Dec. 2021, 日本AEM学会技術賞, 小児用人工心臓のための超小型磁気浮上モータの改良, 日本AEM学会
Toru Masuzawa;Masahiro Osa
Japan society

20 Oct. 2018, 日本AEM学会論文賞, JAPAN, The Japan Society of Applied Electromagnetics and Mechanics
増澤徹;長真啓
Official journal

Oct. 2018, 日本AEM学会論文賞, ダブルステータ型アキシャルギャップ磁気浮上モータの5軸制御方式を活用した小児用人工心臓循環補助時の外乱力推定と磁気浮上特性評価, The Japan Society of Applied Electromagnetics and Mechanics
増澤徹,長真啓
Official journal

26 Oct. 2017, 日本AEM学会論文賞, ラジアル型セルフベアリングモータにおける受動安定性の簡易推定式の検討, 日本AEM学会
増澤徹;小沼弘幸;村上倫子
Japan society

Oct. 2017, 日本AEM学会論文賞, ラジアル型セルフベアリングモータにおける受動安定性の簡易推定式の検討, 日本AEM学会
増澤徹,小沼弘幸.村上倫子
Japan society

Sep. 2013, Japanese Society for Artificial Organs Best Paper Award in 2013, Effect of metal surface characteristics on the adhesion performance of the integrated low-level energies method of adhesion, Japanese Society for Artificial Organs
Aodai T;Masuzawa T;Ozeki H;Kishida A;Higami T

Nov. 2011, 平成23年度日本AEM学会技術賞, 治療用人工心臓のためのアキシャル型磁気浮上モータの開発，日本AEM学会誌Vol.19，No.2，2011, 日本AEM学会

Oct. 2011, 平成23年度茨城大学学長学術表彰優秀賞, 国立大学法人茨城大学

Nov. 2010, Japanese Society for Artificial Organs Best Paper Award in 2010, Estimation of changes in dynamic hydraulic force in a magnetically suspended centrifugal blood pump with transient computational fluid dynamics analysis, Japanese Society for Artificial Organs
Masuzawa T;Ohta A;Tanaka N;Qian Y;Tsukiya T

Nov. 2009, 日本AEM学会功労賞, 日本AEM学会
増澤徹

Nov. 2009, Japanese Society for Artificial Organs SAITO AWARD 2008, Estimation of changes in dynamic hydraulic force in a magnetically suspended centrifugal blood pump with transient computational fluid dynamics analysis, Japanese Society for Artificial Organs
Toru Masuzawa

Nov. 2007, The International Society for Rotary Blood Pumps (ISRBP) Poster Award, Transient CFD analysis for a maglev centrifugal pump, The International Society for Rotary Blood Pumps (ISRBP)
Masuzawa T;Ohta A;Tanaka N;Qian Y;Tsukiya T

Oct. 2007, ライフサポート学会論文賞, Development of a novel hybrid type magnetic bearing and application to small impeller centrifugal pump for artificial hearts, ライフサポート学会
Saito T;Masuzawa T;Nakayama N

2006, 日本人工臓器学会論文賞

2006, ベストCFDグラフィック・アワード

2003, ライフサポート学会論文賞

2001, 日本人工臓器学会論文賞

2000, 東京電機大学ME会第13回高橋賞

1996, 日本機械学会設計工学・システム部門ラピッドプロトタイピングコンテストアイデア賞

1993, 第21回人工心臓と補助循環懇話会 若手研究者最優秀賞

1992, 第20回人工心臓と補助循環懇話会 若手研究者最優秀賞

1991, 日本エム・イー学会論文賞

〔Major achievements〕Homopolar magnetically levitated motor for implantable total articial heart　　　　　　　　　　　　　　　
鈴木修太、増澤徹、川口哲平、長真啓、北山文矢, Corresponding, 日本AEM学会
日本AEM学会誌, 01 Feb. 2024, [Reviewed]

〔Major achievements〕Flow Rate Estimation of a Centrifugal Blood Pump Using the Balance of Control Currents,Through the Electromagnets in the Magnetic Bearing
Shuya SHIDA; Toru MASUZAWA; Masahiro OSA; Yutaka SUZUKI, Last, the Japanese Society for Medical and Biological Engineering
Advanced Biomedical Engineering, 20 Dec. 2023, [Reviewed]

〔Major achievements〕Effects of biventricular shunt on pump,characteristics in a maglev total artificial,heart
Shuya Shida; Kenichi Tsushima; Masahiro Osa; Daniel L Timms and Toru Masuzawa, Last, ESAO
The International Journal of Artificial Organs, 04 Oct. 2023, [Reviewed]

磁気浮上人工心臓のための制御周波数の検討　　　　　　　　　　　　　　　
斎藤広明,増澤徹,長真啓,北山文矢, Corresponding, 日本AEM学会
日本AEM学会誌, 14 Apr. 2023, [Reviewed]

人工心臓のためのMR流体トルク伝達機構　　　　　　　　　　　　　　　
北山文矢,増澤徹,長真啓,佐藤樹,菅原槙人, Corresponding, 日本AEM学会
日本AEM学会誌, 14 Apr. 2023, [Reviewed]

小児用補助人工心臓用5軸制御セルフベアリングモータの駆動系簡素化の検討　　　　　　　　　　　　　　　
長真啓,増澤徹,北山文矢,西中知博,巽英介, 日本AEM学会
日本AEM学会誌, 10 Feb. 2023, [Reviewed]

〔Major achievements〕Radial Passive Stability Analysis of Magnetically Levitated Impeller Position for the Development of Flow Rate Estimations of a Ventricular Assist Device
Shuya Shida; Toru Masuzawa; Masahiro Osa, Corresponding, 生体医工学会
Advanced Biomedical Engineering, 11 Nov. 2022, [Reviewed]

〔Major achievements〕Magnetic suspension performance and energy consumption characteristics of a maglev pediatric VAD using an ultra-compact axial gap type self-bearing motor with different number of actively controlled axes
Toshihiro YAMASHITA; Toru MASUZAWA; Masahiro OSA; Eisuke TATSUMI; Tomohiro NISHINAKA, Corresponding, 掲載決定, 日本AEM学会
日本AEM学会誌, 05 Aug. 2022, [Reviewed]

Dynamic motion analysis of impeller for the development of real-time flow rate estimations of a ventricular assist device
Shuya Shida; Toru Masuzawa; Masahiro Osa, Corresponding, European Society for Artificial Organs
The International Journal of Artificial Organs, 01 Jan. 2022, [Reviewed]

〔Major achievements〕Double Stator Axial Gap Type Ultra-Compact 5-DOF Controlled Self-Bearing Motor for Rotary Pediatric Ventricular Assist Device
Masahiro Osa; Toru Masuzawa; Kiyoshi Yamaguchi; Eisuke Tatsumi, Corresponding, Accepted, IEEE
IEEE Transactions on Industry Applications, 16 Aug. 2021, [Reviewed]

EVALUATION OF DOWNSIZING AND SUSTAINABILITY OF WATER DISTRIBUTION NETWORK IN A MIDDLE SIZED-CITY
藤田 昌史、桑原 祐史、小林 薫 、増澤 徹, 土木学会
土木学会論文集, 16 Jul. 2021, [Reviewed]

Self-Connecting Inflow Cannula to Support Implantation of Ventricular Assist Device　　　　　　　　　　　　　　　
Naoki Yoshida; Toru Masuzawa; Masahiro Osa; Kazuhide Ozeki; Akio Kishida; Tomonori Tsukiya; Toshihide Mizuno; Tomohiro Nishinaka; Eisuke Tatsumi, Corresponding, The Society of Life Support Engineering
Life Support, 08 Jul. 2021, [Reviewed]

Evaluation of Acceleration Resistance of Homopolar Type Magnetic Bearing for Ventricular Assist Device
Yuto Ueda; Toru Masuzawa; Masahiro Osa, Corresponding
Journal of JSAEM, 12 May 2021, [Reviewed]

Evaluation of Energy Saving on the Axial Maglev Motor for Pediatric Ventricular Assist Device
Kiyoshi Yamaguchi; Toru Masuzawa; Masahiro Osa; Eisuke Tatsumi, Corresponding, 日本AEM学会
Journal of JSAEM, 12 May 2021, [Reviewed]

Effects of gravity on flow rate estimations of a centrifugal blood pump using the eccentric position of a levitated impeller
Shuya Shida; Toru Masuzawa; Masahiro Osa, Corresponding, European Society for Artificial Organs
The International Journal of Artificial Organs, 11 May 2020, [Reviewed]

Vessels anastomosis supporting device for coronary artery bypass grafting　　　　　　　　　　　　　　　
Yosuke Haneda; Toru Masuzawa; Masahiro Osa; Kazuhide Ozeki; Akio Kishida; Eisuke Tatsumi, Corresponding, ライフサポート学会
ライフサポート, Oct. 2019, [Reviewed]

Characterizing A Compact 5-DOF controlled Self-Bearing Motor with Modified Magnetic Circuit to Improve Suspension Performance for Pediatric VAD　　　　　　　　　　　　　　　
Masahiro OSA; Toru MASUZAWA; Ryoga ORIHARA; Eisuke TATSUMI, Corresponding, JSAEM
Journal of JSAEM, 01 Jul. 2019, [Reviewed]

小児用人工心臓のための超小型磁気浮上モータの改良
織原涼雅; 増澤徹; 長真啓; 巽英介, Corresponding, 日本AEM学会
Journal of JSAEM, Jun. 2019, [Reviewed]

Improvement of right centrifugal pump using computer fluid dynamics analysis for flow balance regulation of total artificial heart
Tomoyasu Makida; Toru Masuzawa; Shuya Shida; Masahiro Osa; Daniel L Timms, Corresponding, The Society of Life Support Engineering
LIFE SUPPORT, Jun. 2019, [Reviewed]

Performance enhancement of a magnetic system in a ultra compact 5-DOF-Controlled self-bearing motor for a rotary pediatric ventricular assist device to diminish energy input
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi, Corresponding, MDPI
Actuators, 13 Apr. 2019, [Reviewed]

A Double-Sided Stator Type Axial Bearingless Motor Development for Total Artificial Heart
Nobuyuki Kurita; Takeo Ishikawa; Naoki Saito; Toru Masuzawa; Daniel Lee Timms, This paper proposed a bearingless motor that has tilt control function and clarified its fundamental characteristics as a magnetically suspended motor and magnetically suspended pump. The rotor has eight permanent magnets (PMs) on each side (16 PMs in total). The two stators have 12 poles each with two types of concentrated windings. One is for motoring and axial control and the other is for tilt control. This bearingless motor has three degrees of freedom active positioning control. The theoretical analysis clarified operating principle and showed that the proposed motor could control translational motion, inclinational, and rotational movement independently. An experimental setup was fabricated, and the control performance of the self-bearing motor was also investigated. The fabricated prototype achieved a stable magnetically levitated rotation. In addition, the proposed axial self-bearing motor fabricated into a prototype of the magnetically suspended pump to investigate pump characteristics for a total artificial heart applications., Institute of Electrical and Electronics Engineers Inc.
IEEE Transactions on Industry Applications, 01 Mar. 2019

Flow rate estimation of a centrifugal blood pump using the passively stabilized,eccentric position of a magnetically levitated impeller
Shuya Shida; Toru Masuzawa; Masahiro Osa, Corresponding
The International Journal of Artificial Organs, Feb. 2019, [Reviewed]

Consideration of introduction of a correlated double samping to a two-dimensional magnetic sensor and its noise suppresion
Takayuki Kimura; Kouhei Yamane; Toru Masuzawa, A CDS (correlated double sampling) method was applied to two-dimensional magnetic sensors. The two-dimensional integrated magnetic sensor used for the consideration of CDS was composed of a 64 × 64 array of Hall sensors. The size of a Hall element was 2.7 × 2.7 µm 2 and a pixel size was 7 × 7 µm 2 . By the results of meausrement, FPN(fixed pattern noise) in the reproduced image sampled at 3.2 µs was suppressed to 1.27 mV rms, Institute of Electrical Engineers of Japan
IEEJ Transactions on Sensors and Micromachines, 2019

Magnetic suspension performance enhancement of ultra-compact 5-DOF controlled self-bearing motor for rotary pediatric ventricular assist device　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi, Corresponding, ISMB
Proc. of the 16th ISMB, 01 Aug. 2018

人工心臓への適用を目的とした４軸制御型磁気軸受の開発　　　　　　　　　　　　　　　
小泉綾香; 増澤徹; 長真啓, Corresponding
日本AEM学会誌, 10 Jun. 2018, [Reviewed]

心拍同期型磁気浮上体外循環血液ポンプの径方向安定性評価　　　　　　　　　　　　　　　
佐藤遼太; 増澤徹; 長真啓; 大野康平; 西村隆; 許俊鋭, Corresponding
日本AEM学会誌, 10 Jun. 2018, [Reviewed]

全置換型磁気浮上人工心臓への反発型永久磁石磁気軸受の組み込み　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 國府田芳彰; 長真啓; Daniel L TIMMS, Corresponding, 日本AEM学会
日本AEM学会誌, Jun. 2018, [Reviewed]

ダブルステータ型アキシャルギャップ磁気浮上モータの5軸制御方式を活用した小児用人工心臓循環補助時の外乱力推定と磁気浮上特性評価　　　　　　　　　　　　　　　
長真啓; 増澤徹; 斎藤拓也; 巽英介, Corresponding, 日本AEM学会
日本AEM学会誌, 10 Mar. 2018, [Reviewed]

薄小型補助人工心臓用セルフベアリングモータの改良　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭, Corresponding, 日本AEM学会
日本AEM学会誌, 10 Mar. 2018, [Reviewed]

Motor design and impeller suspension
Toru Masuzawa; Masahiro Osa; Martin Mapley, Motor design over the past century has been a thoroughly researched area
however, the motor requirements for rotary blood pumps (RBPs) are typically unique in nature. As with other applications, they are required not only to be highly efficient, reliable, and compact but also to possess hemocompatibility characteristics, such as large clearances between the rotor and stator and the use of noncontact bearing systems, to ensure long-term patient support. An understanding of the interaction and production of electromagnetic forces inside a motor along with control methods and design topologies is essential for developing a highly efficient, reliable, compact, and hemocompatible motor for use in a RBP., Elsevier Inc.
Mechanical Circulatory and Respiratory Support, 2018

Analysis of the effect of the size of three-dimensional micro-geometric structures on physical adhesion phenomena using microprint technique　　　　　　　　　　　　　　　
Akiko Oota-Ishigaki; Toru Masuzawa; Kazuaki Nagayama, Corresponding
The International Journal of Artificial Organs, 2018, [Reviewed]

Effects of eccentric impeller position on radial passive stability in a magnetically levitated centrifugal blood pump with a double volute
Shuya Shida; Toru Masuzawa; Masahiro Osa; Ryota Sato, Evaluation of the impeller radial stability is important from the bioengineering point of view in the development of mechanical circulatory support devices (MCSDs) for safer use as bridge for several months or destination therapy for years. In this study, radial stability of a magnetically levitated impeller in a centrifugal blood pump with an axially magnetic suspension system was evaluated by investigating the effects of the eccentric impeller position on passive stability, aiming to propose a pump design guide for the development and safer clinical use of MCSDs. First, impeller displacements in the prototype pump were measured using a mock loop together with laser displacement sensors. Then, the radial hydraulic forces exerted on an eccentric impeller were calculated using computational fluid dynamics (CFD) analysis for four volute-casing geometries. In addition, hemocompatibility was assessed using CFD calculations of scalar shear stress exerted on blood. Measurement of impeller displacement showed that the displacement varied from 0.56 to 0.27 mm at a rotational speed of 1800 rpm as the flow rate increased from 0 to 6.5 L/min. In the CFD calculation, the radial hydraulic force increased linearly from 0.2 to 1.7 N as the impeller displacement increased from 0 to 0.5 mm for all the double volute geometries, under conditions of a rotational speed of 1800 rpm and flow rates of 3, 5 and 7 L/ min. These results indicate that the impeller stability in the prototype pump is acceptable at the operation conditions of ventricular assist devices, because the magnetic bearing stiffness of radial component was 4.1 N/mm. In the pressure recovery analysis of eccentric impellers, a double volute was not effective because of the unbalanced pressure field generated by the unbalanced pressure recovery. Thus, the increase in radial hydraulic force associated with an eccentric impeller could not be avoided by changing the conventional double volute design. The CFD analysis of geometrical variation indicated that widening of the radial clearance is an effective approach to improve the radial stability as well as hemocompatibility, although the radial clearance should be designed based on trade-offs among impeller stability, hemocompatibility and pump performance., Japanese Society for Medical and Biological Engineering
Advanced Biomedical Engineering, 2018, [Reviewed]

Magnetic levitation performance of miniaturized magnetically levitated motor with 5-DOF active control
Masahiro Osa; Toru Masuzawa; Takuya Saito; Eisuke Tatsumi, Corresponding,

Mechanical circulatory support (MCS) therapy plays a significant role in an alternative therapy of heart transplants for pediatric heart disease patients. However, continuous flow rotary MCS devices for pediatric patients are still undergoing development, and have not been clinically available technology. Technical difficulties, such as high durability, better blood compatibility and miniature device size, prevent the pediatric MCS devices development. In this study, a double stator axial gap maglev motor for pediatric MCS device has been developed. The maglev motor has two identical motor stators, and a levitated rotor impeller which is aligned between the stators. The levitated rotor impeller is fully suspended with 5-degrees of freedom (5-DOF) active control. A double stator mechanism enhances motor torque production. A miniaturized maglev motor was designed and developed based on FEM magnetic field analysis for use in implantable ventricular assist devices (VADs). The diameter and height of the developed maglev motor are 22 mm and 33 mm. This paper is an initial report on the magnetic levitation and rotation performance of the miniaturized maglev motor. The levitated rotor impeller was magnetically levitated and rotated with the 5-DOF active control. The oscillation amplitudes (x, y and z) and inclination angles (θx and θy) of the levitated rotor impeller were then evaluated in both air and water. The developed maglev motor achieved non-contact rotation up to 1600 rpm in air and 4500 rpm in water, respectively. The oscillation amplitudes and inclination angles were sufficiently suppressed in water due to fluid damping. After these experiments, a magnetic circuit of the maglev motor was modified in order to achieve further stable levitation. The developed maglev motor then indicated potential to achieve the practical use of maglev rotatory pediatric VAD.

, JSME
Mechanical Engineering Journal, 15 Oct. 2017, [Reviewed]

Magnetic levitation performance of miniaturized magnetically levitated motor with 5-DOF active control
Masahiro Osa; Toru Masuzawa; Takuya Saito; Eisuke Tatsumi, Corresponding,

Mechanical circulatory support (MCS) therapy plays a significant role in an alternative therapy of heart transplants for pediatric heart disease patients. However, continuous flow rotary MCS devices for pediatric patients are still undergoing development, and have not been clinically available technology. Technical difficulties, such as high durability, better blood compatibility and miniature device size, prevent the pediatric MCS devices development. In this study, a double stator axial gap maglev motor for pediatric MCS device has been developed. The maglev motor has two identical motor stators, and a levitated rotor impeller which is aligned between the stators. The levitated rotor impeller is fully suspended with 5-degrees of freedom (5-DOF) active control. A double stator mechanism enhances motor torque production. A miniaturized maglev motor was designed and developed based on FEM magnetic field analysis for use in implantable ventricular assist devices (VADs). The diameter and height of the developed maglev motor are 22 mm and 33 mm. This paper is an initial report on the magnetic levitation and rotation performance of the miniaturized maglev motor. The levitated rotor impeller was magnetically levitated and rotated with the 5-DOF active control. The oscillation amplitudes (x, y and z) and inclination angles (θx and θy) of the levitated rotor impeller were then evaluated in both air and water. The developed maglev motor achieved non-contact rotation up to 1600 rpm in air and 4500 rpm in water, respectively. The oscillation amplitudes and inclination angles were sufficiently suppressed in water due to fluid damping. After these experiments, a magnetic circuit of the maglev motor was modified in order to achieve further stable levitation. The developed maglev motor then indicated potential to achieve the practical use of maglev rotatory pediatric VAD.

, JSME
Mechanical Engineering Journal, 15 Oct. 2017, [Reviewed]

Development of a small magnetic levitated centrifugal blood pump using a radial type self-bearing motor and axial position change of rotor-impeller by rotational magnetic field
Hiroyuki Onuma; Toru Masuzawa; Michiko Murakami, Last,

A small magnetic levitated centrifugal blood pump using a radial type self-bearing motor has been developed for use as an implantable artificial heart. In order to realize an implantable blood pump for a small adult patient, miniaturization and high efficiency of the device are necessary. In this study, a radial type self-bearing motor which is small-diameter and thin was developed, and the axial position change of the rotor-impeller by the rotational magnetic field was proposed. Magnetic suspension characteristics and motor performance were compared the center axial position of the rotor with the displaced axial position of the rotor. Additionally, a magnetic levitated centrifugal blood pump using the self-bearing motor was developed, and pump performance and levitation performance were measured. The magnetic suspension performance in the radial direction was enough ability to control the radial position of the rotor. The magnetic suspension force in the radial direction decreased by displacing the axial position of the rotor. The passive stability performance in the axial direction was enough ability to suspend the rotor. The restoring force was possible to be varied by the rotation magnetic field. The motor performance decreased by shifting the phase angle of the rotational magnetic field from 90 degrees and displacing the axial position of the rotor. At the operating condition with a flow rate of 5 L/min against a pressure of 100 mm Hg, the oscillation amplitude in x, y, z direction were 0.014 mm, 0.014 mm and 0.039 mm, respectively. And, the total power consumption was 7.1 W. The developed magnetic levitated centrifugal blood pump has demonstrated sufficient levitation performance and low total power consumption. The average displacement in z direction of the rotor-impeller was possible to change by changing the phase angle of the rotational magnetic field. By decreasing the phase angle from 90 degrees in range of from 60 degrees to 90 degrees, it is possible to improve the levitation performance with just a little increases the total power consumption.

, JSME
Mechanical Engineering Journal, 15 Oct. 2017, [Reviewed]

Compact Maglev Motor with Full DOF Active Control for Miniaturized Rotary Blood Pumps　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi, LDIA2017
Proc. of LDIA2017, 01 Sep. 2017

作動流体粘度が磁気浮上補助人工心臓のポンプ特性およびインペラ浮上性能に与える影響
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭, Corresponding, ライフサポート学会
ライフサポート学会誌, 31 Aug. 2017, [Reviewed]

超小型磁気浮上式小児用人工心臓の開発
斎藤拓也; 増澤徹; 長真啓; 巽英介, Corresponding,

A 5-degrees of freedom (5-DOF) controlled maglev motor and a centrifugal blood pump have been developed for pediatric ventricular assist devices (VADs). The magnetically suspended pediatric VAD consists of a top stator, a bottom stator and a levitated impeller. A double stator mechanism enhances a torque production. The maglev pediatric VAD has an outer diameter of 22 mm, a total length of 34 mm and a total volume of 18 cc. In this study the pump performance of the developed centrifugal pump was investigated, as well as the magnetic suspension ability of the developed 5-DOF controlled self-bearing motor was evaluated. The developed maglev pediatric VAD produced a flow rate up to 2.5 L/min against a pump head pressure of 100 mmHg at an impeller rotating speed of 5000 rpm. The maximum oscillation amplitudes that were 0.08 mm in axial direction and 0.19 mm in radial direction were less than the clearance of the centrifugal blood pump.

, The Japan Society of Applied Electromagnetics and Mechanics
日本AEM学会誌, 10 Jul. 2017, [Reviewed]

全置換型磁気浮上人工心臓のための反発型磁気軸受の検討
國府田芳彰; 増澤徹; 長真啓; Dniel L Timms, Corresponding,

We have developed a magnetically levitated total artificial heart. The stator of the device has a magnetic bearing and a motor stator set at center of the device. The left and right impellers are connected by a shaft through the center hall of the stator core. The axial position and tilting of the levitated impeller are controlled by the magnetic bearing. The radial displacement of the impeller is supported with a passive stability. We propose the application of a repulsive passive permanent magnetic bearing, PMB, for improvement of the radial stiffness of the device. A magnetic field analysis with finite element method was performed to investigate a suitable PMB. As a result, the PMB which has two radially magnetized outer permanent magnets and an axial magnetized inner permanent magnet has better performance and the radial stiffness increased up to 2.5 times of passive stability's one.

, The Japan Society of Applied Electromagnetics and Mechanics
日本AEM学会誌, 10 Jul. 2017, [Reviewed]

The motion of levitated impeller at maglev cascade pump for thin ventricular assist device
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭, Corresponding, ライフサポート学会
ライフサポート学会誌, 30 Jun. 2017, [Reviewed]

Effect of flow around three-dimensional micro-geometric structures on adhesion phenomena
Akiko Oota-Ishigaki; Toru Masuzawa; Takayuki Shibata, Corresponding, ライフサポート学会
ライフサポート学会誌, 30 Jun. 2017, [Reviewed]

Magnetically suspended motor system applied to artificial hearts and blood pumps
Toru Masuzawa, Magnetic levitation technology, for magnetic bearings and magnetically suspended motors, is a cutting edge technology to produce artificial hearts and higher performance blood pumps. A wider blood gap and the elimination of the contacting parts in the device based on the maglev technology provide better blood compatibility and higher durability of the device. Several maglev pumps developed at Ibaraki University are introduced in this article. Maglev pumps have been designed for different medical requirements and for different magnetic suspension systems. All pumps have sufficient suspension and pump performance as blood pumps. The axial suspension system with a double biased hybrid magnetic bearing is explained in detail as one example of maglev blood pumps., SAGE PUBLICATIONS LTD
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART I-JOURNAL OF SYSTEMS AND CONTROL ENGINEERING, May 2017, [Reviewed]

心拍同期型磁気浮上血液ポンプにおける受動安定軸の浮上安定性評価　　　　　　　　　　　　　　　
下堀拓己; 増澤徹; 西村隆; 許俊鋭, Corresponding, 日本AEM学会
日本AEM学会誌, 10 Sep. 2016, [Reviewed]

ラジアル型セルフベアリングモータにおける受動安定性の簡易推定式の検討　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹; 村上倫子, Corresponding
日本AEM学会誌, 10 Sep. 2016, [Reviewed]

Development of radial type self-bearing motor for small centrifugal blood pump　　　　　　　　　　　　　　　
Hiroyuki ONUMA; Toru MASUZAWA and Michiko MURAKAMI, Corresponding
15th International Symposium on Magnetic Bearings, 03 Aug. 2016, [Reviewed]

Thermal denaturation behavior of collagen fibrils in wet and dry environment
Yosuke Suwa; Kwangwoo Nam; Kazuhide Ozeki; Tsuyoshi Kimura; Akio Kishida; Toru Masuzawa, We have developed a new minimally invasive technique--integrated low-level energy adhesion technique (ILEAT)--which uses heat, pressure, and low-frequency vibrations for binding living tissues. Because the adhesion mechanism of the living tissues is not fully understood, we investigated the effect of thermal energy on the collagen structure in living tissues using ILEAT. To study the effect of thermal energy and heating time on the structure of the collagen fibril, samples were divided in two categories-wet and dry. Further, atomic force microscopy was used to analyze the collagen fibril structure before and after heating. Results showed that collagen fibrils in water denatured after 1 minute at temperatures higher than 80 degrees C, while partial denaturation was observed at temperatures of 80 degrees C and a heating time of 1 min. Furthermore, complete denaturation was achieved after 90 min, suggesting that the denaturation rate is temperature and time dependent. Moreover, the collagen fibrils in dry condition maintained their native structure even after being heated to 120 degrees C for 90 min in the absence of water, which specifically suppressed denaturation. However, partial denaturation of collagen fibrils could not be prevented, because this determines the adhesion between the collagen molecules, and stabilizes tissue bonding. (c) 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 538-545, 2016., WILEY-BLACKWELL
JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS, Apr. 2016, [Reviewed]

Improvement of maglev cascade pump for a ventricular assist device toward practical use
Watanabe Yasuaki; Masuzawa Toru; Murakami Michiko; Onuma Hiroyuki; Nishimura Takashi; Kyo Shunei,

A maglev ventricular assist device implanted under the thorax muscle layer has been developed for mild heart disease patients. A radial gap maglev motor and a cascade pump are adopted to make the device thinner. The design of the device was modified to improve pump performance and anatomical fitting using a computational fluid dynamic analysis. A motor diameter is enlarged from 30 mm to 35 mm to improve motor performance. An inlet port was bent toward a ventricular side with an angle of 30 degrees for better fitting. An angle between the inlet and outlet ports was adjusted to 60 degrees. The CFD simulation indicates higher pressure production performance by 30 % of a previous device without any negative effect with the bending port. The pump can produce a sufficient flow rate of 2 L/min against a head pressure with a rotating speed of 1800.

, Japanese Society for Medical and Biological Engineering
Transactions of Japanese Society for Medical and Biological Engineering, 2016

Miniaturizing 5-DOF fully controlled axial gap maglev motor for pediatric ventricular assist devices
Masahiro Osa; Toru Masuzawa; Takuya Saito; Eisuke Tatsumi, An axial gap maglev motor with double stators that can control five-degrees of freedom (5-DOF) of rotor postures has been newly developed for pediatric ventricular assist devices (VADs). The motor has two stators that have an identical structure and a levitated rotor. The rotor is levitated magnetically between the stators and is driven by the mechanism of a synchronous permanent magnet motor. A double-stator structure achieves active 5-DOF posture control and enhances torque production. In this paper, a maglev motor as an actuator of pediatric VAD has been designed and miniaturized based on magnetic field FEM analysis. The performance of the maglev motor, the static magnetic suspension force and the torque of the developed motor, is measured experimentally and is sufficient for stable levitation and rotation., IOS PRESS
INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS, 2016, [Reviewed]

A double sided stator type axial self-bearing motor development for left ventricular assist devices
Nobuyuki Kurita; Takeo Ishikawa; Naoki Saito; Toru Masuzawa, A self-bearing motor that has tilt control function is proposed. The rotor has two permanent magnets on each side (four PMs in total). The two stators have eight poles each with concentrated windings. The operating principle was clarified by theoretical analysis and FEM analysis. Moreover, it was shown that the proposed motor can control the translation motion, inclinational and rotational motion independently. An experimental setup was fabricated and magnetically levitated rotation was achieved. The control performance of the self-bearing motor was also investigated. In addition, the proposed axial self-bearing motor is also designed and fabricated into a prototype maglev pump. Fabricated pump test rig showed sufficient performance for left ventricular assist device (LVAD) application of 4.35 L/min at 100 mm Hg., IOS PRESS
INTERNATIONAL JOURNAL OF APPLIED ELECTROMAGNETICS AND MECHANICS, 2016, [Reviewed]

Radial position active control of double stator axial gap self-bearing motor for pediatric VAD　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Naoki Omori; Eisuke Tatsumi, Corresponding
Mechanical Engineering Journal, 15 Aug. 2015, [Reviewed]

IPM型5軸制御セルフベアリングモータの小型化とコギングトルク特性改善に関する研究
松田健一; 熊谷渉; 近藤良; 増澤徹, Last, 5-DOF self-bearing motor possesses the functions of a motor, two radial active magnetic bearings (AMBs), and an axial AMB. It is possible to downsize the AMB system while still maintaining a high level of support performance. In a 5-DOF self-bearing motor, the IPM rotor generates bias fluxes in not only the radial direction but also in the axial and tilt directions without any side surface permanent magnets. However, cogging torques are inherently generates by the magnetic flux flow in a IPM rotor. The proposed flux recovery-type permanent magnets configuration was analyzed using the 3-dimensional finite element method. The results show a significant reduction of the cogging torques and an improvement to motor efficiency., The Japan Society of Mechanical Engineers
日本機械学会論文集, 18 Jun. 2015, [Reviewed]

磁気浮上型心臓治療用血液ポンプへのセンサレスモータ制御の適用　　　　　　　　　　　　　　　
大森直樹; 増澤徹; 長真啓; 下堀拓己; 西村隆; 許俊鋭, Corresponding
日本AEM学会誌, 10 Jun. 2015, [Reviewed]

薄小型磁気浮上補助人工心臓における浮上インペラの受動安定軸の変動計測　　　　　　　　　　　　　　　
吉田翔一; 増澤徹; 村上倫子; 小沼弘幸; 西村隆; 許俊鋭, Corresponding
日本AEM学会誌, 10 Jun. 2015, [Reviewed]

Size-reduced two-dimensional integrated magnetic sensor fabricated in 0.18μm CMOS process
Takayuki Kimura; Kazuya Uno; Toru Masuzawa, Last, Two-dimensional integrated magnetic sensors have been investigated in order to reduce their size for use in a magnetic self-levitation motor. The two-dimensional integrated magnetic sensor investigated in this paper is composed of a 16 x 16 array of Hall sensors and fabricated by a 0.18-m complementary metal-oxide-semiconductor (CMOS) standard process. The sizes of the Hall elements are 1 x 1, 2 x 2, 3 x 3, and 6 x 6 m(2). Hall element of dimension 1 x 1 m(2)was the minimum size in the fabrication process rule. The dimension of one pixel in which the Hall element was embedded was 20 x 20 m(2). The average sensitivity of the arrayed Hall sensors at four sizes was about 0.140 mV/mT with a DC magnetic field. The product sensitivity at four sizes of Hall sensors was about 0.089 mV/(mAmT), which is better than that of our previous work. Degradation of the product sensitivity was not seen in reduced-size Hall elements. These results reveal that a Hall element of size 1 x 1 m(2) has enough sensitivity for sensing the impeller position of a magnetically suspended motor. (c) 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc., WILEY-BLACKWELL
IEEJ Trans, May 2015, [Reviewed]

全置換型磁気浮上人工心臓と流量バランス制御
山田悠; 増澤徹; Daniel L TImms, Corresponding, An innovative Bi-Ventricular Artificial Heart (IB-Heart) has been successfully developed with a single magnetically suspended motor. The device has auto flow regulation function which reacts to atrial pressure change in order to balance the flow rate of left and right pump. The zero power control is adopted to control axial position of levitated impeller in the IB-Heart. The rate of change of the axial position of the impeller on the atrial pressure change is the key factor of this devices flow regulation function since the flow rate of the pumps is regulated with axial position changing of the levitated impeller. The flow regulating ability of the IB-Heart and the relationship between the rod cross-sectional area and the flow regulation function was investigated. The maglev motor was redesigned with 3-D magnetic field analysis to improve the flow regulation function., The Japan Society of Applied Electromagnetics and Mechanics
日本AEM学会誌, 10 Mar. 2015, [Reviewed]

小児用補助人工心臓のための小型磁気浮上モータの第一試作
大森直樹; 増澤徹; 長真啓; 巽英介, Corresponding, A miniaturized magnetically levitated motor which can actively control 5-degrees of freedom (5-DOF) of impeller postures has been newly developed for a paediatric ventricular assist device (VAD). Developed motor consists of a top stator, a bottom stator and a levitated impeller that is set between the both stators. The diameter and the height of the motor are 28 mm and 41 mm, respectively. Magnetic field analysis with finite element method was performed in order to design the geometry of motor permanent magnets and a stator. Corners of the motor permanent magnets were cut to produce sinusoidal distribution of magnetic flux density and to reduce the cogging torque. The developed maglev motor produces sufficient suspension force and rotates the levitated impeller up to a rotating speed of 6000 rpm with sufficient posture control performance., The Japan Society of Applied Electromagnetics and Mechanics
日本AEM学会誌, 10 Mar. 2015, [Reviewed]

磁気ビーズを用いた磁気励振細胞刺激システム
増澤 徹; 服部圭介; 林照剛; 木村剛; 岸田晶夫, Lead, We have been investigating the mechanical cell stimulation because it has the possibility to enhance cell function without any chemical and biological material. In this paper, a newly developed cell stimulation system using magnetic beads attached on the cell wall is presented. The magnetic beads are attached on cultured cells in advance and an alternating magnetic field produced by the electric magnet is exposed onto the cells attached the magnetic beads. The beads are vibrated with the magnetic field and the cell wall received the vibration stimulation. Basic performance of the stimulation system is evaluated in this paper. The system can produce an attractive force of 30 pN onto the beads and can vibrate the beads up to a vibration frequency of 80 Hz with an oscillation amplitude of 450 nanometers. The vibration of the magnetic beads on the cultured cells with a vibration frequency of 10 Hz was observed successfully with human mesenchymal stem cells., The Japan Society of Applied Electromagnetics and Mechanics
日本AEM学会誌, 10 Mar. 2015, [Reviewed]

回転数周期的変動時の磁気浮上型血液ポンプの浮上安定性と溶血性能の検討
増澤徹; 山口聡史; 下堀拓己; 西村隆; 許俊鋭, Lead, A novel blood pump with magnetically levitated impeller has been developed to recover cardiac function of acute heart failure patients. The pump assists patients heart and the impellers rotational speed are changed based on synchronizing with heart beat in order to increase coronary flow of patients heart. Impeller levitation stability of the pump operated in pulsatile mode was evaluated with a mock circuit filled with water. In the pulsatile mode, the rotational speed was changed from 800 rpm to 1800 rpm with a beat rate of 60 bpm. Maximum axial displacement of the impeller is 22 % of the blood gap between the impeller and casing. Characteristics of hemolysis of the pump were examined within in-vitro hemolysis tests. NIH value of the maglev pump is about half time of it of a commercial based extracorporeal pump in constant speed operation. Even NIH value operated in the pulsatile mode is about two times of the commercial based pumps one and it is acceptable range for clinical usage. The developed maglev pump indicates sufficient impeller levitation stability and hemolysis property., The Japan Society of Applied Electromagnetics and Mechanics
日本ＡＥＭ学会誌, 10 Mar. 2015, [Reviewed]

Effect of incorporation of deuterium on vacancy-type defects of a-C：H films prepared by plasma CVD　　　　　　　　　　　　　　　
K.Ozeki; D.Sekida; A.Uedono; K.K.Hirakuri; T.Masuzawa, Last
Applied Surface Science, 03 Jan. 2015, [Reviewed]

Pediatric VAD with Five Degrees of Freedom Control MAGLEV Motor　　　　　　　　　　　　　　　
T. Masuzawa; M. Osa; N. Omori; E. Tatsumi
41st Annual European Society for Artificial Organs (ESAO) Congress, 17 Sep. 2014, [Invited]

The relationship between the thrombogenicity and the generated flow around 3-dimensional micro geometrical structures on the bio-material -Investigation of micro flow-　　　　　　　　　　　　　　　
Ota-Ishigaki A; Masuzawa T; Shibata T; Kawashima T; Maruyama O
The 10th International Student Conference at Ibaraki University, 15 Sep. 2014

Cadiovascular circulation simulator to evaluate ventricular assist effect　　　　　　　　　　　　　　　
Kurosaki W; Masuzawa T
The 10th International Student Conference at Ibaraki University, 15 Sep. 2014

アウターロータ型5軸制御セルフベアリングモータに関する研究　　　　　　　　　　　　　　　
松田健一; 平根龍也; 近藤良; 増澤徹
日本ＡＥＭ学会誌, 10 Sep. 2014, [Reviewed]

Cascade pump for mechanical circulatory support
Toru Masuzawa; Michiko Murakami, Cascade pump has a rotating disk with circumferential vanes. Flow channel is constructed around the circumferential space of the rotating disk. The cascade pump has thin structure because the inlet and outlet ports are set on the same plane with the rotating disk. The gap between disk surface and casing should be less than 0.05 mm to prevent pressure loss through the gap in the cascade pump. The gap of the cascade pump produces higher hemolysis and thrombus in it. The disk surface gap is minimized with modifying the impeller to ring shape with a radial self-bearing motor to achieve better blood compatibility. Developed pump has maximum diameter of 59 mm and a thickness of 22 mm. Maximum flow rate and head pressure are 7 L/min and 330 mmHg, respectively. The hemolysis property is just two times of the commercial based blood pump and sufficient for mechanical circulatory support., Japan Soc. of Med. Electronics and Biol. Engineering
Transactions of Japanese Society for Medical and Biological Engineering, 17 Aug. 2014, [Reviewed]

Total artificial heart with a single maglev motor
Toru Masuzawa; Daniel L. Timms, A total artificial heart which has a single maglev motor with double centrifugal pumps has been developed. The maglev motor is set between a left pump and a right pump. The impellers of the left and right pumps are connected with a connecting rod passed through at the center of the motor. The impellers are levitated magnetically and rotated with identical rotating speed. The flow balance between the left and right pumps is achieved by shifting the levitated impeller in the axial direction. Zero power control is adopted for preload sensitive control. The maximum diameter and height of the pump are 76 mm and 61 mm, respectively. The pump indicates sufficient pump performance with the maximum flow rate of 20 L/min in usage condition. The flow rate is changed more than by 10 % of the flow rate of the pumps with an impeller position changing of 0.4 mm., Japan Soc. of Med. Electronics and Biol. Engineering
Transactions of Japanese Society for Medical and Biological Engineering, 17 Aug. 2014, [Reviewed]

Magnetically suspended motor system for artificial hearts and blood pumps　　　　　　　　　　　　　　　
Masuzawa T
14th International Symposium on Magnetic Bearings, 11 Aug. 2014, [Reviewed]

Optimization design of magnetically suspended system for the BiVACOR total artificial heart　　　　　　　　　　　　　　　
Kurita N; Timm D; Greatrex N; Kleinheyer M; Masuzawa T
14th International Symposium on Magnetic Bearings, 11 Aug. 2014, [Reviewed]

Radial Position Active Control of Double Stator Axial Gap Self-bearing Motor for Paediatric VAD　　　　　　　　　　　　　　　
Osa M; Masuzawa T; Omori N; Tatsumi E
14th International Symposium on Magnetic Bearings, 11 Aug. 2014, [Reviewed]

Thin Maglev Ventricular Assist Device with radial Type Self-bearing Motor　　　　　　　　　　　　　　　
Murakamia M; Masuzawa T; Yoshida S; Onuma H; Nishimura T; Kyo S
14th International Symposium on Magnetic Bearings, 11 Aug. 2014, [Reviewed]

Evaluation of Magnetic Suspension Characteristics and Levitation Performance of A Centrifugal Blood Pump Using Radial Type Self-Bearing Motor　　　　　　　　　　　　　　　
Onuma H; Masuzawa T
14th International Symposium on Magnetic Bearings, 11 Aug. 2014, [Reviewed]

Magnetically suspended artificial heart　　　　　　　　　　　　　　　
Masuzawa T
8th Asia-Pacific Symposium on Applied Electromagnetics and Mechanics 2014, 23 Jul. 2014, [Invited]

小児用人工心臓のための小型5軸制御セルフベアリングモータ
長真啓; 増澤徹; 大森直樹; 巽英介, 日本AEM学会
日本ＡＥＭ学会誌, 10 Jun. 2014, [Reviewed]

12突極ラジアル型セルフベアリングモータの磁気支持特性の推定　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹
日本AEM学会誌, 10 Jun. 2014, [Reviewed]

Pulsatile operation of the BiVACOR TAH - Motor design, control and hemodynamics
Matthias Kleinheyer; Daniel L. Timms; Nicholas A. Greatrex; Toru Masuzawa; O. Howard Frazier; William E. Cohn, Although there is limited consensus about the strict requirement to deliver pulsatile perfusion to the human circulatory system, speed modulation of rotary blood pumps is an approach that may capture the benefits of both positive displacement and continuous flow blood pumps. In the current stage of development of the BiVACOR Total Artificial Heart emphasis is placed on providing pulsatile outflow from the pump. Multiple pulsatile speed profiles have been applied in preliminary in-vivo operation in order to assess the capability of the TAH to recreate a physiologic pulse. This paper provides an overview about recent research towards pulsatile BiVACOR operation with special emphasis on motor and control requirements and developments., IEEE
2014 36TH ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY (EMBC), 2014, [Reviewed]

シングル磁気浮上モータ方式全人工心臓の開発
西村宣彦; 増澤徹; ダニエルLティムス, A magnetically suspended total artificial heart has been developed with a single magnetically suspended motor. The device has double pumps to replace the function of the left and right ventricles. A stator which has both of a magnetic bearing core and a motor stator core is set at center of the device. The left and right pump impellers are connected with a rod through the center hall of the stator core. Attractive forces produced by the magnetic bearing and the motor are made balance to suspend the rotating impellers. Flow difference between the left and the right pump is regulated by changing the amount of the secondary flow through blood gap between impeller top edge and pump casing by shifting the impeller position axially. Flow rate of the left pump is changed 4.1∼6.7 L/min, flow rate of the right pump is changed 6.5∼7.4 L/min when axial position of the impeller is shifted by ±0.2 mm., The Japan Society of Applied Electromagnetics and Mechanics
日本ＡＥＭ学会誌, 10 Jun. 2013

Influence of the source gas ratio on the hydrogen and deuterium content of a-C:H and a-C:D films: Plasma-enhanced CVD with CH4/H-2, CH4/D-2, CD4/H-2 and CD4/D-2
K. Ozeki; D. Sekiba; T. Suzuki; K. Kanda; M. Niibe; K. K. Hirakuri; T. Masuzawa, Amorphous hydrogenated carbon (a-C:H) and amorphous deuterated carbon (a-C:D) films were prepared using plasma-enhanced chemical vapor deposition (PECVD) from CD4, H-2, CD4 and D-2 source gases. Fourteen different samples were prepared by changing the source gas ratios of CH4/H-2, CH4/D-2, CD4/H-2, and CD4/D-2. The concentrations of hydrogen (H) and deuterium (D) relative to carbon (C) in the films were determined by elastic recoil detection analysis (ERDA) and Rutherford backscattering spectroscopy (RBS). The sp(2)/(sp(2) + sp(3)) ratios of the films were analyzed by near-edge X-ray absorption fine structure (NEXAFS) measurements. Hardness and mass density of the films were measured using a nanoindenter and X-ray reflectivity (XRR), respectively. For all combinations of source gas, the H and D concentrations varied by only 4.0 at.%. For the CH4/D-2 source gas, the D concentration in the film increased from 0 at.% with the D-2/(CH4 + D-2) source gas combination to 11.2 at.% for the 80% D-2/(CH4 + D-2) source gas combination. The increase in D concentration exceeded the increase in total H and D concentration (3.4 at.%). For CH4/D-2 source gas, the H concentration decreased as the D concentration increased. For the CD4/H-2 source gas, we observed the opposite tendency. Additionally, an isotope effect between the a-C:H films and the a-C:D films was observed, with preferential incorporation of H over D. From the NEXAFS measurements, the sp(2)/(sp(2) + sp(3)) ratios in all of the samples were between 38.8% and 40.8%. A correlation between the sp(2)/(sp(2) + sp(3)) ratio and the H-2 or D-2 gas source ratio was not observed. The hardness and density of the films decreased when the H-2 or D-2 source gas ratio increased. Even though the H concentration in the a-C:H films was higher than the D concentration in the a-C:D films, the a-C:D films had lower hardness and mass density values. These findings suggest that information concerning the voids, nanostructures, sp(2)/sp(3) ratios and H concentrations of hydrogenated amorphous carbon films is crucial for evaluation of their mechanical properties. (C) 2012 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV
APPLIED SURFACE SCIENCE, Jan. 2013, [Reviewed]

Phase Composition of Sputtered Film from a Mixture Target of Hydroxyapatite and Strontium-apatite
Ozeki K; Hoshino T.; Aoki H; Masuzawa T, To obtain an Sr-substituted hydroxyapatite thin film, sputter-coating was performed on a cellulose filter acting as a substrate from the mixture target of hydroxyapatite (HA) and strontium-apatite (SrAp) at an Ar pressure of 0.5-5.0 Pa. The ratio of the SrAp in the mixture target was varied from 25% to 100%. After coating, the films were heated at 700 degrees C to remove the cellulose filter substrate, and the crystalline phases were identified by X-ray diffraction (XRD). The sputter-coated film was identified as the Sr-substituted beta-tri-calcium phosphate (TCP) and the Sr-substituted beta-calcium pyrophosphate (CPP) as well as the Sr-substituted HA. The weight ratio of the Sr-substituted HA decreased with increasing Ar pressure or with an increasing ratio of SrAp to HA in the target. The average Sr/(Ca + Sr) molar ratio in the film was 1.9%-3.5% slightly lower than the initial SrAp ratio of the target, and the ratio was not influenced by the Ar pressure. In the (Sr + Ca)/P ratio, the ratio decreased while increasing the SrAp ratio in the target., JOURNAL MATER SCI TECHNOL
Journal of Materials Science and Technology, 2013, [Reviewed]

Antithrombogenicity of Amorphous Deuterated Carbon Film Prepared by RF-plasma CVD　　　　　　　　　　　　　　　
K. Ozeki; D. Sekiba; K.K. Hirakuri and T. Masuzawa
Nano Biomedicine, 2013, [Reviewed]

The adsorptive behavior of albumin and lysozyme proteins on rod-shaped and plate-shaped hydroxyapatite
K. Ozeki; T. Hoshino; H. Aoki and T. Masuzawa, The adsorption behavior of albumin (BSA) and lysozyme (LSZ) on rod-shaped and plate-shaped hydroxyapatite (HA) was investigated to evaluate the influence of crystal orientation and morphology on the selective protein adsorption of HA. The rod-shaped HA was prepared by hydrothermal treatment from beta-tricalcium phosphate (beta-TCP) in H3PO4 solution (pH 2.0 and 4.0 for HA-pH 2.0 and HA-pH 4.0). The plate-shaped HA was synthesized by hydrolysis of CaHPO4-2H(2)O (DCPD) in NaOH solution at 40 degrees C and 80 degrees C (HA-40 degrees C and HA-80 degrees C). The synthesized HA was characterized using scanning electron microscopy (SEM) and X-ray diffractometry (XRD). HA-pH 2.0 and HA-pH 4.0 produced rod-shaped crystals that were highly oriented to the a-face plane, whereas HA-40 degrees C and HA-80 degrees C showed a plate-like shape and a c-face preferred orientation. The peak intensity ratio I(300)/I(002) (a/c intensity ratio) from the XRD patterns increased in the following order: HA-80 degrees C, HA-40 degrees C, HA-pH 2.0 and HA-pH 4.0. It also increased as the Ca/P ratio decreased. The amount of adsorbed BSA increased in the following order: HA-pH 4.0, HA-pH 2.0, HA-40 degrees C and HA-80 degrees C. The amount of adsorbed LSZ on HA increased in the following order -HA-pH 2.0, HA-pH 4.0, HA-40 degrees C and HA-80 degrees C - with a corresponding decrease in the a/c intensity ratio. The BSA/LSA adsorption ratio increased with the a/c intensity ratio in the range of 3.3-8.9, and the BSA and LSZ were selectively adsorbed on HA, depending on the crystal shape., IOS PRESS
Bio-Med. Mat. Eng, 2013, [Reviewed]

Development of Cell Culture Microdevice Integrated with Piezoelectric Thin Film Actuator for On-Chip Regulation of Cell Functions
Takahiro Kawashima; Yuhei Yamada; Yuuta Matsuzawa; Moeto Nagai; Takayuki Shibata; Toru Masuzawa; Tsuyoshi Kimura; and Akio Kishida, To develop a cell culture microdevice integrated with piezoelectric thin film actuators for on-chip cell function regulation, we investigated various fabrication processes including the formation of a lead zirconate titanate (PZT) thin film using a sol-gel method as a piezoelectric thin film actuator and PZT thin film patterning. According to our proposed batch fabrication process, a prototype cell culture microdevice with 16 microchambers and PZT actuators was successfully fabricated on a 20 x 20mm(2) Si substrate. Moreover, we used the fabricated prototype device to investigate the effects of applied voltage and frequency on diaphragm displacement. The device sufficiently delivered mechanical vibratory stimuli to cells in culture solution. Moreover, in a feasibility study using living cells, we observed that mechanical vibratory stimulation affected cell adhesion. (C) 2012 The Japan Society of Applied Physics, JAPAN SOC APPLIED PHYSICS
Japanese Journal of Applied Physics, 04 Oct. 2012, [Reviewed]

スパッタリング法を用いたストロンチウムアパタイト薄膜の作製と骨芽細胞による評価
星野智大; 尾関和秀; 後藤哲哉; 増澤徹; 青木秀希, バイオインテグレーション学会
バイオインテグレーション学会, Aug. 2012, [Reviewed]

Effect of metal surface characteristics on the adhesion performance of the integrated low-level energies method of adhesion　　　　　　　　　　　　　　　
Aodai T; Masuzawa T; Ozeki K; Kishida A; Higami T
Journal of Artificial Organs, Aug. 2012, [Reviewed]

Development of Lorentz force type tilt control motor for rotary blood pumps　　　　　　　　　　　　　　　
Ichinose T; Masuzawa T; Steinseifer U; Timms D
日本AEM学会誌, Jun. 2012, [Reviewed]

A radial type self-bearing motor for small maglev regenerative blood pump　　　　　　　　　　　　　　　
Ukita K; Masuzawa T; Onuma H; Nishimura T; Kyo S
日本AEM学会誌, Jun. 2012, [Reviewed]

Miniaturized axial gap maglev motor with vector control for pediatric artificial heart　　　　　　　　　　　　　　　
Osa M; Masuzawa T; Tatsumi E
Journal of the Japan Society of Applied Electromagnetics and Mechanics, Jun. 2012, [Reviewed]

Development of Cell Culture Microdevice Actuated by Piezoelectric Thin Films for Delivering Mechanical Vibratory Stimuli to Cells
Yuhei Yamada; Genki Umegaki; Takahiro. Kawashima; Moeto Nagai; Takayuki Shibata; Toru Masuzawa; Tsuyoshi Kimura; Akio Kishida
Journal of Physics: Conference Series, Mar. 2012, [Reviewed]

人工心臓のための12突極ラジアル型磁気浮上モータにおける最適極数の検討　　　　　　　　　　　　　　　
小沼弘幸; 浮田啓悟; 増澤徹
日本AEM 学会誌, Mar. 2012, [Reviewed]

小型ローレンツ型磁気浮上モータのサーボモータ制御　　　　　　　　　　　　　　　
岡田養二; 三好理文; 増澤徹; 榎園正人
日本AEM 学会誌, Mar. 2012, [Reviewed]

Study on Permanent Magnet Arrangement for IPM Type 5-DOF Self-Bearing Motor
MATSUDA Kenichi; KONDO Ryou; MASUZAWA Toru, The 5-DOF self-bearing motor possesses the functions of a motor, two radial AMBs, and an axial AMB. Therefore, it is possible to miniaturize the AMB system with maintaining high performance. In this paper, an interior permanent magnet (IPM) type 5-DOF self-bearing motor is proposed. The IPM rotor generates bias fluxes to not only the radial direction but also the overhanging stator direction without side surface permanent magnets. Optimum configuration of the permanent magnets is analyzed using 3 dimensional finite element method. The results show the feasibility of the more compact and highly-reliable 5-DOF self-bearing motor., The Japan Society of Mechanical Engineers
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A, 2012

全人工心臓用アキシャル型磁気軸受の最適化に関する研究
西村宣彦; 増澤徹; ダニエル L ティムス
電気学会研究会資料リニアドライブ研究会LD-11-067～077, 24 Nov. 2011

Development of Lorentz force type tilt control motor for rotary blood pumps　　　　　　　　　　　　　　　
Takannori Ichinose; Toru Masuzawa; Ulrich Steinseifer; Daniel Timms
Proceedings of the 20th MAGDA Conference in Pacific Asia, 30-35, 2011.11.14, 14 Nov. 2011

Miniaturized axial gap maglev motor with vector control for pediatric artificial heart　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Eisuke Tatsumi
Proceedings of the 20th MAGDA Conference in Pacific Asia, 14 Nov. 2011

BiVACORⓇ-A Magnetically levited biventricular artificial heart
Daniel Timms; Nobuyuki Kurita; Nicholas Greatrex; Toru Masuzawa
Proceedings of the 20th MAGDA Conference in Pacific Asia, 14 Nov. 2011

完全人工心臓用カスケードポンプ(ACCEL PUMP)の左心用ポンプの評価　　　　　　　　　　　　　　　
福長一義; 阿部裕輔; 山家智之; 巽英介; 増澤徹; 山根隆志; 妙中義之; 井街宏; 舟久保昭夫; 福井康裕
人工臓器, Oct. 2011, [Reviewed]

治療用人工心臓のためのアキシャル型磁気浮上モータの開発　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 西村隆; 許俊鋭
日本AEM学会誌, Jul. 2011, [Reviewed]

乳児用人工心臓用ダブルステータ型磁気浮上モータの開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽 英介
日本AEM学会誌, Jul. 2011, [Reviewed]

アウターロータ型5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
松田 健一; 寺山 昌幸; 近藤 良; 増澤 徹
日本機械学会論文集Ｃ編, 25 May 2011, [Reviewed]

Synthetic polymer-tissue adhesion using an ultrasonic scalpel
Yamamoto K; Kimura T; Nam K; Funamoto S; Ito Y; Shiba K; Katoh A; Shimizu S; Kurita K; Higami T; Masuzawa T; Kishida A, Interface phenomena such as encapsulation and formation of dead space around implanted biomaterials lower biomaterial performance. To advance tissue adhesive technology, understanding the interactions between tissue (collagen) and polymer is indispensable. Adhesion between tissue and polymer was studied using an ultrasonically activated scalpel (UAS).
The Harmonic Scalpel was used as an ultrasonically activated scalpel for polymer and tissue adhesion. A piece of porcine aorta and a polymeric film were layered and placed between the blades of the Harmonic Scalpel. Then the samples were gripped with 20 kgf of force for 1-10 s to adhere the porcine aorta and polymeric films. The adhesion was characterized by macro- and microscopic observation, thermographic analysis, and measurement of bonding strength, static contact angle (SCA), and surface properties.
Cellulose, vinylon, polyethylene telephthalate, nylon, and Pellethane(A (R)) could be bonded to the aorta. Bonding was not observed for the polyethylene, polypropylene, polyvinyl chloride, or polytetrafluoroethylene. This suggests that the existence of functional groups such as hydroxyl, carbonyl, carboxyl, and amide groups in the polymer structure are key factors in adhesion. Harmonic Scalpel modification of the polyethylene surface during corona discharge treatment further indicated that the functional groups of the polymers are one of the essential factors for tissue adhesion. The temperatures of adhesion were 90-150A degrees C for the polymers, and the melting temperatures (Tm) were 193-306A degrees C. This suggests that adhesion was formed by the interaction between the melted polymer surface and the tissue collagen.
Both polar functional groups and adequate thermal characteristics are necessary for polymers to bond with tissues. These findings should be useful for the development of novel polymers that can be bonded to living tissues with UAS treatment, which can be applied for endoscopic surgery., SPRINGER
Surgical Endoscopy, Apr. 2011, [Reviewed]

Investigation of sensitivity of two-dimensional integrated magnetic sensor fabricated in sub-micron CMOS process
Takayuki Kimura; Hitoshi Furuya; Toru Masuzawa, To realize a high-resolution two-dimensional integrated magnetic sensor, the process rule was changed from 0.35 to 0.18 /im. The fabricated magnetic sensor was an n-type Hall sensor that uses an inversion layer under the gate oxide of the MOSFET. The decided sensor area size was 6.6 × 6.6νm 2. The Hall sensors were arrayed in 32×32 pixels. The average sensitivity of the fabricated magnetic sensors was 34.6mV/(mAT), and this value was the same as that of fabricated magnetic sensors in the 0.35μm standard CMOS process. No degradation of sensitivity was introduced to a magnetic sensor fabricated in 0.18 μm process rule. From the result of two-dimensional integrated magnetic sensor, two-dimensional magnetic flux distribution was successfully measured from the 1-mm diameter Nd-Fe-B rare-earth permanent magnet. By changing the position of the probe that measures Hall voltage, the sensitivity of magnetic sensors was increased by 17%.
Kyokai Joho Imeji Zasshi/Journal of the Institute of Image Information and Television Engineers, Mar. 2011

Effects of vibration on differentiation of cultured PC12 cells
ItoY; KimuraT; NamKW; Kato A; Masuzawa T; Kishida A, Different types of physiological-mechanical stress, such as shear stress in vascular endothelial cells or hydrostatic pressure in chondrocytes are well known as regulators of cell function. In this study, the effects of vibration, a type of non-physiological mechanical stimulation, on differentiation of rat pheochromocytoma (PC12) cells are reported. A nano-vibration system was designed to produce nanometer-scale vibration. The frequency and amplitude of the nano-vibrations were monitored by a capacitance displacement sensor connected to an oscilloscope. When PC12 cells exposed to nerve growth factor were subjected to vibration at 10 kHz, differentiation and elongation of their neurites were promoted earlier in the culture. Vibration promoted differentiation of PC12 cells. This approach could therefore also be promising for determining of the effects of the physical environment on cell differentiation. Biotechnol. Bioeng. 2011;108: 592-599. (C) 2010 Wiley Periodicals, Inc., JOHN WILEY & SONS INC
Biotechnology & Bioengineering., Mar. 2011, [Reviewed]

Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene　　　　　　　　　　　　　　　
K.Ozeki; K.K.Hirakuri; T.Masuzawa
Applied Surface Science, Feb. 2011

サブミクロンプロセスで製造された2次元集積化磁気センサにおける感度特性に関する研究　　　　　　　　　　　　　　　
木村孝之; 古谷仁; 増澤徹
映像情報メディア学会誌, 2011, [Reviewed]

Nano-vibration effect on cell adhesion and its shape
Yukiko Ito; Tsuyoshi Kimura; Yusuke Ago; Kwangwoo Nam; Kaori Hiraku; Kozo Miyazaki; Toru Masuzawa and Akio Kishida, Extracellular physical features of underlying the adhesive substrate affect cell adhesion to it substrate. In this study, the effects of vibration, a type of artificial physical stimulation, on the adhesion of mouse L929 cells, mouse embryonic fibroblasts (MEFs), HeLa cells and human umbilical vein endothelial cells (HUVECs) are reported. A nano-vibration system was designed to produce nanometer-scale vibration. When L929 cells, HeLa cells, and HUVECs were subjected to vibration at 100 Hz and 1 kHz, they were not affected. On the other hand, in MEFs, the adherent cells were increased and changed their shape remarkably in response to 1 kHz vibration. To investigate the MEFs' sensitivity to vibration in detail, the cells shape was classified into four types; round, stellate, filopodia-formed and lamellipodia-formed. In serum addition culture, 1 kHz vibration increased the number of filopodia-formed cells but decreased lamellipodia cells. Furthermore, the preliminary cDNA microarray experiments showed that expression of genes which regulate cytoskeleton were changed by vibration stimulation. These results suggest that vibration could affect cell adhesion and the determination cell shape., IOS PRESS
Bio-Medical Materials and Engineering, 2011, [Reviewed]

Feasibility Study of Cell Culture Microdevice actuated by Piezoelectric Thin Film for on-Chip Regulation of Cell Functions　　　　　　　　　　　　　　　
Takahiro Kawashima; Takayuki Shibata; Moeto Nagai; Toru Masuzawa; Tsuyoshi Kimura and Akio Kishida
Proc. of The 14th International Conference on Miniaturized Systems for Chemistry and Life Sciences (μTAS 2010), Oct. 2010, [Reviewed]

アウターロータ型5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
松田健一; 寺山昌幸; 近藤良; 増澤徹
日本機械学会［No.10-8]Dynamics and Design Conference 2010 CD-ROM論文集, 14 Sep. 2010

Development of Flux Concentrated type Self-Bearing Motor
Okada Y; Kitagou K; Masuzawa T; Enokizono M, Self-bearing motor has combined function of AC motor and magnetic bearing. Usually lévitation force is produced by Maxwell force while the motor torque is produced by Lorentz force. The authors have proposed Lorentz type self-bearing motor where strong magnetic flux is the key technology for good characteristics. In this paper three types of rotors are designed and compared: a flux concentrated PM rotor, Halbach rotors with iron back yoke and aluminum back yoke. The high density flat coils are designed and used for the stator. The experimental setup is fabricated and tested. The results obtained are compared and discussed in details. © 2010 IFAC., IFAC Secretariat
5th IFAC Symposium on Mechatronic Systems, 13 Sep. 2010

Japanese guidance for ventricular assist devices/ total artificial hearts
Yamane T; Kyo S; Matsuda H; Abe Y; Imachi K; Masuzawa T; Nakatani T; Sase K; Tabayashi K; Takatani S; Tatsumi E; Umezu M, To facilitate research and development (R&D) and to expedite the review processes of medical devices, the Ministry of Health, Labor and Welfare (MHLW) and the Ministry of Economy, Trade and Industry (METI) founded a joint committee to establish guidance for newly emerging technology. From 2005 to 2007, two working groups held discussions on ventricular assist devices and total artificial hearts, including out-of-hospital programs, based on previous guidance documents and standards. Based on this discussion, the METI published the R&D Guidelines for innovative artificial hearts in 2007, and in 2008 the MHLW published a Notification by Director regarding the evaluation criteria for emerging technology., WILEY-BLACKWELL PUBLISHING, INC
Artificial Organs, Sep. 2010, [Reviewed]

Miniaturized Magnetically Levitated Motor for Pediatric Artificial Heart　　　　　　　　　　　　　　　
Osa M; Masuzawa T; Tatsumi E
Proceedings the 12th International Symposium on Magnetic Bearings (ISMB 12), Aug. 2010

Axial Magnetic Bearing Development for the BiVACOR Rotary BiVAD/TAH
Greatrex NA; Timms DL; Kurita N; Palmer EW; Masuzawa T, A suspension system for the BiVACOR biventricular assist device (BiVAD) has been developed and tested. The device features two semi-open centrifugal impellers mounted on a common rotating hub. Flow balancing is achieved through the movement of the rotor in the axial direction. The rotor is suspended in the pump casings by an active magnetic suspension system in the axial direction and a passive hydrodynamic bearing in the radial direction. This paper investigates the axial movement capacity of the magnetic bearing system and the power consumption at various operating points. The force capacity of the passive hydrodynamic bearing is investigated using a viscous glycerol solution. Axial rotor movement in the range of +/- 0.15 mm is confirmed and power consumption is under 15.5 W. The journal bearing is shown to stabilize the rotor in the radial direction at the required operating speed. Magnetic levitation is a viable suspension technique for the impeller of an artificial heart to improve device lifetime and reduce blood damage., IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
IEEE Transactions on Biomedical Engineering, Mar. 2010, [Reviewed]

二次元集積化磁気センサのフレームレート向上に関する研究
木村孝之; 横山裕大郎; 増澤徹, To improve the frame rate of a two-dimensional integrated magnetic sensor, the pixel structure and readout circuits were re-examined. The frame rate was improved by reducing the noise of the horizontal shift register by lowering the drive frequency and parallel reading (with 16 channels). With this idea, two-dimensional integrated magnetic sensors were designed and fabricated with the standard 0.35 μm CMOS process on silicon. The type of Hall sensor is n-type Hall sensor that uses an inversion layer under the gate oxide of the MOSFET. The Hall sensors were arrayed (64×64), and the control digital circuits and output amplifier were also integrated into the same chip. "One pixel" was 50×50 μm, and the entire chip was 4.9×4.9 mm. The frame rate was 7813 frames/sec at a 2-MHz horizontal shift register frequency. The average sensitivity of these sensors was 72.9 mV/(mA·T). The two-dimensional magnetic flux distribution was measured with a 3000-rpm, 1-mm-diameter Nd-Fe-B rare-earth permanent rotating magnet without image lag. From the measurement results, a high frame-rate magnetic sensor for motor control was successfully fabicated., The Institute of Image Information and Television Engineers
映像情報メディア学会, Mar. 2010, [Reviewed]

Design and basic characteristics of permanent magnet hybrid type axial magnetic bearings
Nobuyuki Kurita; Youhei Takahashi; Takeo Ishikawa; Daniel Timms; Nicholas Greatrex; Toru Masuzawa, In order to improve rotor-impeller suspensi performance of the developing ventricular assist device, ax magnetic bearing with various permanent magnet arrangeme are designed and fabric stator shows wide l © 2010 IEEE.
Digests of the 2010 14th Biennial IEEE Conference on Electromagnetic Field Computation, CEFC 2010, 2010, [Reviewed]

Influence of the hydrothermal temperature and pH on the crystallinity of a sputtered hydroxyapatite film
Ozeki K; Aoki K; Masuzawa T, Hydroxyapatite (HA) was coated onto titanium substrates using radio frequency sputtering, and the sputtered films were crystallized under hydrothermal conditions at 110-170 degrees C at pH values of 7.0 and 9.5. The crystallite size, the remnant film thickness, and the surface morphology of the films were observed using X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy, respectively.
The crystallite size increased with the process temperature, and reached 123.6 nm (pH 9.5 and 170 degrees C) after 24 h. All of the crystallite sizes of the film treated at pH 9.5 were higher than those treated at pH 7.0 at each process temperature. The film treated at pH 9.5 retained more than 90% of the initial film thickness at any process temperature. The ratio of the film treated at pH 7.0 did not reached 90% at less than 150 degrees C, and tended to increase with the process temperature. (C) 2010 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV
Applied Surface Science, 2010, [Reviewed]

Adsorptive properties of albumin, fibrinogen, and gamma-globulin on fluorinated diamond-like carbon films coated on PTFE
Ozeki K; Magashima I; Hirakuri KK; Masuzawa T, Fluorinated diamond-like carbon (F-DLC) films were deposited on polytetrafluoroethylene (PTFE) using radio frequency (RF) plasma-enhanced chemical vapor deposition (CVD) by changing the ratio of tetrafluoromethane (CF(4)) and methane (CH(4)). To enhance the adhesion strength of the F-DLC film to the PTFE substrate, the PTFE surface was modified with a N(2) plasma pre-treatment. XPS analysis of the films showed that the C-C bond decreased with increases in the CF(4) ratio, whereas the C-F bond increased with the CF(4) ratio. The F/C ratio of the film also increased with the CF(4) ratio. The pull-out test showed that the adhesion strengths of the films (CF(4)-0-60%) were improved with the plasma pre-treatment. In the film without the plasma pre-treatment, adhesion strength increased with the CF(4) ratio. In contrast, in the case with the plasma pre-treatment, the adhesion strength of the F-DLC film decreased with the increased CF(4) ratio. Regarding the adsorption of albumin, fibrinogen, and gamma-globulin, the amount of adsorbed albumin on the film decreased with an increasing CF(4) ratio, and the amount of adsorbed fibrinogen and gamma-globulin increased with the CF(4) ratio. The CF(4)-0% DLC film showed the most adsorbed albumin and the least adsorbed fibrinogen and gamma-globulin. This indicates that the CF(4)-0% DLC film has higher anti-thrombogenicity than the F-DLC film., SPRINGER
J Mater Sci: Mater Med, 2010

The wear properties and adhesion strength of the diamond-like carbon film coated on SUS, Ti and Ni-Ti with plasma pre-treatment
Ozeki K; Masuzawa T; Hirakuri KK, Diamond-like carbon (DLC) films were deposited on stainless steel (SUS), titanium (Ti) and nickel titanium (Ni-Ti) substrates using a radiofrequency plasma chemical vapour deposition method. Prior to DLC coating, the substrates were exposed to O(2) and N(2) plasma to enhance the adhesion strength of the DLC film to the substrate. After the plasma pre-treatment, the chemical composition and the wettability of the substrate surface was investigated by X-ray photoelectron spectroscopy (XPS) and water contact angle measurement, respectively. A pull-out test and a ball-on-disc test were carried out to evaluate the adhesion strength and the wear properties of the DLC-coated substrates.
The XPS results showed that the N(2) and O(2) plasma pre-treatment produced nitride and oxide on the substrate surfaces, such as TiO(2), TiO, Fe(2)O(3), CrN and TiNO. In the pull-out test, the adhesion strengths of the DLC film to the SUS, Ti and Ni-Ti substrates were improved with the plasma pre-treatment. In the ball-on-disc test, the DLC coated SUS, Ti and Ni-Ti substrates without the plasma pre-treatment showed severe film failure following the test. The DLC coated SUS and Ni-Ti substrates with the N(2) plasma pre-treatment showed good wear resistance, compared with that with the O(2) plasma pre-treatment., IOS PRESS
Bio-Medical Materials and Engineering, 2010, [Reviewed]

Cross-sectional hydrogen content and mass density profiles of diamond-like carbon film by neutron and X-ray reflectivity
Ozeki K; Saitoh H; Takeda M; Ohgoe Y; Hirakuri KK; Yonemura M; Masuzawa T, The cross-sectional profiles of hydrogen content and mass density of diamond-like carbon (DLC) film were investigated using X-ray and neutron reflectivity. DLC films were prepared using a plasma CVD technique by varying the H(2)/(H(2) + CH(4)) ratio gas source from 0 to 0.9. The cross-sectional hydrogen content and mass density profiles of the films were calculated by neutron and X-ray reflectivity, and the results were compared with those from elastic recoil detection analysis (ERDA).
The fitted simulation showed that the mass density gradually decreased with increasing depth, whereas the hydrogen content increased with depth. In both ERDA and reflectivity measurements, the average hydrogen content was more than 30% in all films and tended to increase with the H(2)/(CH(4) + H(2)) ratio. However, there was a difference in hydrogen content values between the two analyses ranging from 5.1% to 8.5%. (C) 2009 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA
Diamond & Related Materials, 2010, [Reviewed]

Development of tissue adhesion method using integrated low-level energies
Katoh A; Masuzawa T; Ozeki K; Kishida A; Kimura T; and Higami T, We have developed a method that allows biological tissues to be adhered together with minimal invasion by delivering integrated low-level energies from heat, pressure, and vibration. Tensile tests on adhered slices of porcine aorta were performed to determine the relationships between adhesive strength and conditions such as adhesion temperature, time, pressure, and vibration. The maximal adhesive shear tensile strength using the proposed method was 0.2 MPa, which is half the strength of the porcine aorta and stronger than surgical tissue adhesive. Adhesion strength increased in proportion to temperature, time, and pressure, and also in the presence of vibration, indicating that vibrational energy contributes to the adhesive mechanism and strength. Adhesive stability, the effect of heat on adhesive strength, and the ability of tissue to adhere to artificial materials were also clarified. (C) 2010 IPEM. Published by Elsevier Ltd. All rights reserved., ELSEVIER SCI LTD
Medical Engineering & Physics, 2010, [Reviewed]

両心補助人工心臓BiVACOR Bi-VAD用磁気浮上モータ
増澤 徹; 佐々木瑛祐; ダニエル L ティムス, We have developed a new assist device BiVACOR for bi-ventricular support. In this paper, newly developed magnetically suspended motor for the BiVACOR is reported. BiVACOR has double pumps for left and right ventricular assist driven by single magnetically suspended motor (MSM). Flow difference between the left and the right pump is regulated by changing the amount of the second flow through blood gap between impeller top edge and pump casing by shifting the impeller position axially. New MSM has a combined core for magnetic bearing and motor. Both of the impellers are set at the both end of the integrated core. Back surface of the left pump impeller faced to the core side has permanent magnets to construct the hybrid magnetic bearing with the core that electric magnets for the magnetic bearing are constructed on. Permanent magnets for motor are set on back surface of the right pump impeller. Both impellers are connected rigidly with a center shaft through the center hall of the stator core. Attractive forces produced by the motor and the magnetic bearing are made balance to suspend the rotating impellers. The axial position of the impellers is adjusted with the magnetic bearing when the flow balance between the left and right pump is changed. Performance of the developed MSM as an actuator for BiVACOR was evaluated. The new MSM is rotated with levitation up to a rotating number of 4,800rpm. Vibration amplitude with a rotating number of 2,000rpm is only 27 micro meters and the axial position of the impeller is controllable in the range of 500 micro meters. The developed MSM has sufficient performance as an actuator of the BiVACOR., 日本AEM学会
日本AEM学会, 2010, [Reviewed]

Characterization of cell culture microdevice integrated with piezoelectric thin film actuator for delivering mechanical vibratory stimuli to cells　　　　　　　　　　　　　　　
Kawashima T; Matsuzawa Y; Shibata T; Nomura M; Masuzawa T; Kishida A
Proc. of 3rd International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2009), 2E-13 (in CD-ROM, 4pp), Nov. 2009, [Reviewed]

5-DOF Controlled Self-Bearing Motor
Ishikawa T; Matsuda K; Kondo R; Masuzawa T, A novel 5-DOF actively controlled self-bearing motor that combines the functions of a motor, two radial AMBs, and an axial AMB has been developed to achieve smaller size and higher performance simultaneously. In this paper, magnetic suspension performance of the 5-DOF controlled self-bearing motor is reported. First, radial control performance of the developed self-bearing motor is evaluated by the radial experimental setup. Next, tilt control performance and 5-DOF active control performance are evaluated by the 5-DOF experimental setup. Finally, the frequency response in the 5-DOF is measured with the contact-free levitation. The 5-DOF controlled self-bearing motor produced sufficient radial force and tilt control torque to overcome the radial negative stiffness and to stabilize the rotor. The sufficient frequency bandwidth was observed in the frequency response and the self-bearing motor successfully suppressed vibration at the resonant frequencies., The Japan Society of Mechanical Engineers
Journal of System Design and Dynamics, Jul. 2009, [Reviewed]

4軸制御型磁気軸受を用いた磁気浮上クリーンポンプの研究開発
黒須寛秋; 増澤徹; 加藤綾子; 小沼弘幸; 柿原功一, A new hybrid magnetic bearing and motor system with wide air gaps has been developed, and a magnetically suspended clean pump with the system has been developed. The optimization method to determine the optimal values of the design parameters has been developed based on magnetic equivalent circuit technique, genetic algorithm and three dimensional magnetic field analysis. The size of the hybrid magnetic bearing C core, the thickness of the permanent magnets, and the turn number of the electromagnets are optimized by the method. The developed system has an outer diameter of 100mm, a length of 140mm, and air gaps of 3.5mm. And the developed pump has an outer diameter of 100mm, a length of 160mm. The measured ratio of force to excitation current is 36.4N/A. The rotor-impeller could be driven up to a rotational speed of 6000rpm without touching anywhere. The developed pump indicates sufficient pump performances which are maximum pump head of 9.37mH_2O and maximum flow rate of 27.3L/min., 日本AEM学会
日本AEM学会, Jun. 2009, [Reviewed]

Estimation of changes in dynamic hydraulic force in a magnetically suspended centrifugal blood pump with transient computational fluid dynamics analysis
Masuzawa T; Ohta A; Tanaka N; Qian Y; Tsukiya T, The effect of the hydraulic force oil magnetically levitated (maglev) pumps should be studied carefully to improve the suspension performance and the reliability of the pumps. A maglev centrifugal pump, developed at Ibaraki University, was modeled with 926376 hexahedral elements for computational fluid dynamics (CFD) analyses. The pump has a fully open six-vane impeller with a diameter of 72.5 mm. A self-bearing motor suspends the impeller in the radial direction. The maximum pressure head and flow rate were 250 mmHg and 141/min, respectively. First, a steady-state analysis was performed using commercial code STAR-CD to confirm the model's suitability by comparing the results with the real pump performance. Second, transient analysis was performed to estimate the hydraulic force on the levitated impeller. The impeller was rotated in steps of 1 degrees using a sliding mesh. The force around the impeller was integrated at every step. The transient analysis revealed that the direction of the radial force changed dynamically as the vane's position changed relative to the outlet port during one circulation, and the magnitude of this force was about 1N. The current maglev pump has sufficient performance to counteract this hydraulic force. Transient CFD analysis is not only useful for observing dynamic flow conditions in a centrifugal pump but is also effective for obtaining information about the levitation dynamics of a maglev pump., SPRINGER TOKYO
J. Artificial Oragans, 2009, [Reviewed]

Gas barrier properties of diamond-like carbon films coated on PTFE
Ozeki K; Magashima I; Ohgoe Y; Hirakuri KK; Mukaibayashi H; Masuzawa T, Diamond-like carbon (DLC) films were deposited on polytetrafluoroethylene (PTFE) using radio frequency (RF) plasma-enhanced chemical vapour deposition (PE-CVD). Before the DLC coating, the PTFE substrate was modified with a N(2) plasma pre-treatment to enhance the adhesive strength of the DLC to the substrate. The influences of the N(2) plasma pre-treatment and process pressure on the gas permeation properties of these DLC-coated PTFE samples were investigated. In the Raman spectra, the G peak position shifted to a lower wave number with increasing process pressure. With scanning electron microscopy (SEM), a network of microcracks was observed on the surface of the DLC film without N(2) plasma pre-treatment. The density of these cracks decreased with increasing process pressure. In the film subjected to a N(2) plasma pre-treatment, no cracks were observed at any process pressure. In the gas barrier test, the gas permeation decreased drastically with increasing film thickness and saturated at a thickness of 0.2 mu m. The DLC-coated PTFE with the N(2) plasma pre-treatment exhibited a greater reduction in gas permeation than did the samples without pre-treatment. For both sample types, gas permeation decreased with increasing process pressure. (C) 2009 Elsevier B. V. All rights reserved., ELSEVIER SCIENCE BV
Applied surface science, 2009, [Reviewed]

Development of a cost effective gap sensor for magnetic bearings　　　　　　　　　　　　　　　
Okada Y; Ishikawa T; Masuzawa T; Kondo R
日本AEM学会, 2009

Adsorptive property of albumin and streptokinase on sputtered hydroxyapatite film and its antithrombogenicity　　　　　　　　　　　　　　　
Yoshihara H; Ozeki K; Masuzawa T and Aoki H
Applied Surface Science, 22 Aug. 2008, [Reviewed]

５軸能動制御型セルフベアリングモータの開発
松田健一; 石川達也; 増澤徹; 近藤良, This paper proposes a novel self-bearing motor. The rotor of the proposed self-bearing motor has the side surface permanent magnets with the conventional circumferential surface permanent magnets. The overhanging stator is newly fixed to the outside of the original stator core. This joined stator core can generate axial direction force effectively to the integrated rotor. The principle of the axial control force and the tilting control torque generation is shown and the general solutions of the force and the torque are also presented. The fundamental characteristics of the self-bearing motor are analyzed by 3-dimensional magnetic field analysis using finite element method. The results show the high feasibility of the 5-axis active control type self-bearing motor., 日本AEM学会
日本AEM学会, 2008, [Reviewed]

5-DOF Controlled Self-Bearing Motor　　　　　　　　　　　　　　　
Ishikawa T; Matsuda K; Masuzawa T; Kondo R
Proceedings of the 11th International Symposium on Magnetic Bearings, 2008

Wide gap magnetic bearing system for a magnetically suspended clean pump　　　　　　　　　　　　　　　
Kurosu H; Masuzawa T; Katoh A; Suzuki K; Onuma H; Kakihara K
Proceedings of the 11th International Symposium on Magnetic Bearings, 2008

Photolithography system with liquid crystal display as active gray-tone mask for 3D structuring of photoresist
Hayashi T; Shibata T; Kawashima T; Makino E; Mineta T; Masuzawa T, Layer manufacturing is generally utilized for the development of micro electromechanical systems (MEMS) and micro total analysis systems (mu TAS). However, the preparation of multiple masks and repetitive exposure procedure prevents the rapid fabrication of 3D microstructures. An active mask fabrication by using a liquid crystal display (LCD) as an electrically controllable photomask can simplify the layer manufacturing process. In addition, the gray-tone photolithography is available by using LCD lithography system, since the exposure distribution is easily controlled by an LCD. We have developed the LCD mask exposure system by using UV light source. Firstly, the patterning characteristics of the UV photoresist by exposing line and space patterns are evaluated, and then, a fundamental step shape is produced in order to verify the feasibility of gray-tone UV photolithography by using LCD. A shape with a different height can be fabricated without any repetitive exposure and development procedures. Finally, we confirmed the high patterning resolution such as 11 mu m using check patterns and fabricated 3D step shapes by using the LCD as a gray-scale photomask. (C) 2008 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE SA
Sensors and Actuators A, 2008, [Reviewed]

Axial magnetic bearing developments for the Bivacor rotary BIVAD/TAH
Kurita N; Timms D L; Masuzawa T; Greatrex N; Masuzawa T
Proceedings of the 11th International Symposium on Magnetic Bearings, 2008, [Reviewed]

Development of a novel hybrid type magnetic bearing and application to small impeller centrifugal pump for artificial hearts
Takashi Saitoh; Toru Masuzawa; Naohisa Nakayama, We have developed a new hybrid magnetic(HM)bearing system for durable and small size artificial hearts. A prototype maglev pump was also developed to verify the feasibility of the developed HM bearing system. A small impeller centrifugal pump was combined with the HM bearing for the prototype pump. The impeller is levitated by a set of HM bearings at both sides of the impeller. A motor stator is set at the center of the device to rotate the levitated impeller. Maximum rotating speed with complete levitation in the air is15, 000rpm. Maximum oscillation amplitude in the radial direction is 0. 04mm with a target rotating number of5, 000rpm. The developed HM bearing system indicated sufficient levitation performance for the artificial heart and the magnetically levitated centrifugal pump with small impeller also displayed good pump performance as a ventricular assist system., The Society of Life Support Engineering
ライフサポート, Dec. 2006, [Reviewed]

Characteristics of a two-dimensional integrated magnetic sensor for position sensing and motor control
K Takasaki; T Masuzawa, Two-dimensional integrated magnetic sensors for position sensing were designed and fabricated with the standard 0.35-mu m CMOS process on silicon. One such type is the n-type Hall sensor that uses an inversion layer under the gate oxide of the MOSFET. The Hall sensors were arrayed (64 x 64), and the control digital circuits and output amplifier were also integrated into the same chip. 'One pixel' was 50 x 50 mu m, and the entire chip was 4.9 x 4.9 mm. The sensitivity of one of these sensors was 2.7 mV/(mA.kG). The two-dimensional magnetic flux distribution was measured from the 5-mm diameter Nd-Fe-B rare-earth permanent magnet. About 42 s was required to measure one frame. The position of the magnet could be detected with the fabricated sensors. Magnetic sensors using an inversion layer in MOSFETs are useful for position sensing systems, but their noise characteristics, such as poor sensitivity, should be improved. (c) 2006 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc., WILEY
IEEJ Trans, Aug. 2006

Characteristics of a two-dimensional integrated magnetic sensor for position sensing and motor control
Takayuki Kimura; Keigo Takasaki; Toru Masuzawa, WILEY
IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Aug. 2006

Hemolysis resulting from surface roughness under shear flow conditions using a rotational shear stressor
Nishida M; Yamane T; Oshima I; Adachi Y; Masuzawa T, The degree of hemolysis as a function of surface roughness value and roughened area under shear flow conditions was investigated using a rotational shear stressor. The shearing portion of the stressor is cone shaped in its upper and lower positions, with a cylindrical central section. Surface roughness was applied to the cylindrical section. Bovine blood was sheared for 30 min over a set of roughened surfaces of between arithmetic mean roughness (Ra) 0.1 and 0.8 mm covering 10% of the surface area of the cylindrical section (equivalent to 1.8% of the whole blood contact area) at a shear rate of 3750/s. The threshold value thus obtained for rapid increase in hemolysis was between Ra 0.6 and 0.8 mm. When sheared with a roughened surface of Ra 0.8 mm applied to the cylindrical surface at areas between 0 and 100% (equivalent to between 0 and 18% of the whole blood-contacting area), the hemolysis level did not increase from 10 to 100%, but a significant difference was obtained between 0 and 10%. This suggests that red blood cells were destroyed not by fatigue failure caused by rolling on the roughened surface, but due to the high shear stress generated by surface roughness. Moreover, it appears that the shear stress was generated over the entire cylindrical section, regardless of the area of surface roughness., BLACKWELL PUBLISHING
Artificial organs, 2006

509 Optimization of the radially maglev centrifugal pump for artificial heart
ONUMA Hiroyuki; OKADA Yohji; MASUZAWA Toru, The Japan Society of Mechanical Engineers
Proceedings of the JSME Bioengineering Conference and Seminar, 2005

Novel maglev pump with a combined magnetic bearing
Onuma H; Murakami M and Masuzawa T, The newly developed pump is a magnetically levitated centrifugal blood pump in which active and passive magnetic bearings are integrated to construct a durable ventricular assist device. The developed maglev centrifugal pump consists of an active magnetic bearing, a passive magnetic bearing, a levitated impeller, and a motor stator. The impeller is set between the active magnetic bearing and the motor stator. The active magnetic bearing uses four electromagnets to control the tilt and the axial position of the impeller. The radial movement of the levitated impeller is restricted with the passive stability dependent upon the top stator and the passive permanent magnetic bearing to reduce the energy consumption and the control system complexity. The top stator was designed based upon a magnetic field analysis to develop the maglev pump with sufficient passive stability in the radial direction. By implementing this analysis design, the oscillating amplitude of the impeller in the radial direction was cut in half when compared with the simple shape stator. This study concluded that the newly developed maglev centrifugal pump displayed excellent levitation performance and sufficient pump performance as a ventricular assist device., LIPPINCOTT WILLIAMS & WILKINS
ASAIO Journal, Jan. 2005, [Reviewed]

アキシャル型磁気浮上モータを用いた人工心臓用遠心ポンプの開発
小沼弘幸; 加藤勇; 増澤徹, The lifetime of a rotary blood pump as an artificial heart is mainly determined by the durability of mechanical parts such as bearings and seals. The purpose of this study is to develop a durable centrifugal blood pump with self-bearing motor techniques. A magnetically suspended centrifugal blood pump by using an axially levitated motor is reported. The axially levitated motor consists of a top stator, a levitated rotor, a bottom stator, and a permanent magnet bearing. The levitated rotor is set between the top and the bottom stator. The axial position of the rotor is controlled by using the electromagnets. The maximum head pressure and the maximum flow rate of the magnetically suspended centrifugal pump were 200 mmHg and 81/min, respectively. The developed pump displayed good magnetic suspension performance and sufficient pump performance as a ventricular assist device., The Japan Society of Mechanical Engineers
日本機械学会論文集(C編), Jan. 2005, [Reviewed]

離散要素法を用いた微小循環内の血流シミュレーション　　　　　　　　　　　　　　　
岩田賢; 田中伸厚; 増澤徹
ライフサポート, 2005, [Reviewed]

Hemolysis caused by surface roughness under shear flow
Numata Y; Nishida M; Yamane T; Oshima I; Adachi Y; Masuzawa T, In this study, the relationship between the degree of roughness of blood contact surfaces under laminar shear flow conditions and the level of hemolysis resulting from this roughness was investigated using a rotational shear stressor. Unlike previous in vitro experiments that used a pumped circuit, the level of hemolysis was directly evaluated under a constant shear flow. In total, 1.8% of the blood contact area was roughened to an arithmetic mean roughness (Ra) value of between 0.4 and 9.2μm by machine processing and a shear load was applied for 30min at a shear flow rate of 3750s-1. As a result, the threshold Ra value for the induction of hemolysis was found to be between 0.4 and 0.8μm. In addition, the results of this experiment suggested that the high shear stress resulting from surface roughness plays a major role in determining the level of hemolysis caused by surface roughness. © The Japanese Society for Artificial Organs 2005.
J Artif Organs, 2005

Development of Photolithography System with Liquid Crystal Device as Active Mask for Synthesizing DNA Chips
SHIBATA Takayuki; HAYASHI Terutake; NODA Takayuki; MASUZAWA Toru; MAKINO Eiji, The Society of Life Support Engineering
Journal of Life Support Technology, 2004

Improvement of centrifugal blood pump for artificial heart with radially Maglev motor
Onuma Hiroyuki; Masuzawa Toru; Okada Yohji; Tsukiya Tomonori; Taenaka Yoshiyuki, The Society of Life Support Engineering
Journal of Life Support Technology, 2004

Micro magnetically suspended system for an axial flow artificial heart
SAITO T; MASUZAWA T; OKADA Yoji; ONUMA Hiroyuki; KOJIMA J, The Society of Life Support Engineering
Journal of Life Support Technology, 2004

Improvement of magnetically suspended centrifugal blood pump with 3DOFcontrol
MURAKAMI M.; ONUMA H.; MASUZAWA T., The Society of Life Support Engineering
Journal of Life Support Technology, 2004

Axial type self-bearing motor for axial flow blood pump
Y Okada; T Masuzawa; KI Matsuda; K Ohmori; T Yamane; Y Konishi; S Fukahori; S Ueno; SJ Kim, An axial self-bearing motor is proposed which can drive an axial blood pump without physical contact. It is a functional combination of the bi-directional disc motor and the axial active magnetic bearing, where it actively controls single degree-of-freedom motion, while other motions such as lateral vibration are passively stable. For application to a blood pump, the proposed self-bearing motor has the advantages of simple structure and small size. Through the finite element method (FEM) analysis and the experimental test, its good feasibility is verified. Finally, the axial flow pump is fabricated using the developed magnetically suspended motor. The pump test is carried out and the results are discussed in detail., BLACKWELL PUBLISHING INC
ARTIFICIAL ORGANS, Oct. 2003

Magnetically suspended centrifugal blood pump with an axially levitated motor
Masuzawa T; Ezoe S; Kato T; Okada Y, The longevity of a rotary blood pump is mainly determined by the durability of its wearing mechanical parts such as bearings and seals. Magnetic suspension techniques can be used to eliminate these mechanical parts altogether. This article describes a magnetically suspended centrifugal blood pump using an axially levitated motor. The motor comprises an upper stator, a bottom stator, and a levitated rotor-impeller between the stators. The upper stator has permanent magnets to generate an attractive axial bias force on the rotor and electric magnets to control the inclination of the rotor. The bottom stator has electric magnets to generate attractive forces and rotating torque to control the axial displacement and rotation of the rotor. The radial displacement of the rotor is restricted by passive stability. A shrouded impeller is integrated within the rotor. The performance of the magnetic suspension and pump were evaluated in a closed mock loop circuit filled with water. The maximum amplitude of the rotor displacement in the axial direction was only 0.06 mm. The maximum possible rotational speed during levitation was 1,600 rpm. The maximum pressure head and flow rate were 120 mm Hg and 7 L/min, respectively. The pump shows promise as a ventricular assist device., BLACKWELL PUBLISHING INC
Artificial Organs, Jul. 2003

小型電気油圧式アクチュエータを用いた補助人工心臓の開発　　　　　　　　　　　　　　　
佐久間剛太; 増澤徹; 塚原金二; 土本勝也
ライフサポート, Jan. 2003

Shear evaluation by quantitative flow visualization near the casing surface of a centrifugal blood pump
Masahiro Nishida; Takashi Yamane; Yuki Tsukamoto; Kazuyuki Ito; Yoshiaki Konishi; Toru Masuzawa; Tomonori Tsukiya; Seiko Endo; Yoshiyuki Taenaka, To clarify the correlation between high-shear flow and hemolysis in blood pumps, detail shear velocity distribution was quantified by an experimental method with a model centrifugal blood pump that has a series data of hemolysis tests and computational fluid dynamic analyses. Particular attention was paid to the shear velocity near the casing surface in the volute where the high shear causes in circumferentially wide region that is considerable to cause high hemolysis. Three pump models were compared concern with the radial gap width between the impeller and casing (the radial volute width) also with the outlet position whereas the impeller geometry was identical. These casing geometries were as follows : model 1 - the gap width is standard 3 mm and the outlet locates to make a smooth geometrical connection with the volute, model 2 - the gap width is small 0.5 mm and the outlet locates to make the smooth geometrical connection with the volute, and model 3 - the gap width is small 0.5 mm and the outlet locates to hardly make the smooth geometrical connection with the volute but be similar radial position with that of model 1. Velocity was quantified with a particle tracking velocimetry that is one of the quantitative flow visualization techniques, and the shear velocity was calculated. Results showed that all large shear velocity existed within the layers of about 0.1 mm from the casing surface and that those layers were hardly affected by a vane passage even if the gap width is 0.5 mm. They also showed that the maximum shear velocity appeared on the casing surface, and the shear velocities of models 2 and 3 were almost twice as large as that of model 1. This finding is in full corresponding with the results of hemolysis tests which showed that the hemolysis levels of both models 2 and 3 were 1.5 times higher than that of model 1. These results suggest that detailed high-shear evaluation near the casing surface in the volute is one of the most important keys in estimating the hemolysis of a centrifugal blood pump.
JSME International Journal, Series C: Mechanical Systems, Machine Elements and Manufacturing, Dec. 2002

マイクロカプセル模擬血液の剪断応力による破壊特性
丸山 修; 山根隆志; 西田正浩; 筒井達夫; 軸屋智昭; 小野口富夫; 岩崎友美; 増澤徹, Microcapsule suspensions substituted for animal blood were designed as model blood for hemolysis tests of circulatory artificial organs. They included microcapsules, which were likened to erythrocytes, for main components of the suspensions .In this paper, we used two types of microcapsules, whose membrane materials were polyurethane and melamine resin respectively, and the both target sizes were 100μm in diameter. The fractural properties of the capsules in the suspensions were tested under the shear stress, generated by the rotational shear stressor. Flow patterns in the shear stressor were examined with an oil spot method. Polyurethane-capsule suspension showed similar fractural behavior to the bovine blood results under the rotational shear stressor. However, the behavior of melamine-capsule suspensions was different from the bovine blood, though the destructive sensitivity was higher than that of polyurethane-capsule suspension. We conclude that both suspensions with 100μm diameter can be candidates of standard hemolysis test solutions., The Society of Life Support Engineering
ライフサポート, Dec. 2002

Magnetically suspended centrifugal blood pump with a self-bearing motor
Masuzawa T; Onuma H; Kim SJ; Okada Y, A magnetically suspended centrifugal blood pump with a self bearing motor has been developed for long-term ventricular assistance. A rotor of the self bearing motor is actively suspended and rotated by an electromagnetic field without mechanical bearings. Radial position of the rotor is controlled actively, and axial position of the rotor is passively stable within the thin rotor structure. An open impeller and a semiopened impeller were examined to determine the best impeller structure. The outer diameter and height of the impeller are 63 and 34 mm, respectively. Both the impellers indicated similar pump performance. Single volute and double volute structures were also tested to confirm the performance of the double volute. Power consumption for levitation and radial displacement of the impeller with a rotational speed of 1,500 rpm were 0.7 W and 0.04 mm in the double volute, while those in the single volute were 1.3 W and 0.07 mm, respectively. The stator of the self bearing motor was redesigned to avoid magnetic saturation and improve motor performance. Maximum flow rate and pressure head were 9 L/min and 250 mm Hg, respectively. The developed magnetically suspended centrifugal blood pump is a candidate for an implantable left ventricular assist device., LIPPINCOTT WILLIAMS & WILKINS
ASAIO Journal, Jul. 2002

Flow visualization analysis of relative stagnation areas on the impeller surface of a centrifugal blood pump
Ahmed Aouidef; Takashi Yamane; Masahiro Nishida; Masahiro Toyoda; Yuki Tsukamoto; Kazuyuki Ito; Yoshiaki Konishi; Toru Masuzawa; Tomonori Tsukiya; Yoshiyuki Taenaka, Springer Science and Business Media LLC
Journal of Artificial Organs, Dec. 2001

An ultradurable and compact rotary blood pump with a magnetically suspended impeller in the radial direction
Masuzawa T; Kita Y; Okada Y, A magnetically suspended centrifugal blood pump has been developed with a self-bearing motor for long-term ventricular assist systems. The rotor of the self-bearing motor is not only actively suspended in the radial direction, but also is rotated by an electromagnetic field, The pump has a long lifetime because there are no mechanical parts such as seals and motor bearings. An outer rotor mechanism was adopted for the self-bearing motor. The stator was constructed in the central space of the motor. The rotor shaped thin ring was set at the circumferential space of the stator. Six vanes were extended from the upper surface of the rotor toward the center of the pump to construct an open-type impeller. The outer diameter and the height of the impeller are 63 mm and 34 mm. respectively. The magnetic bearing method and the servomotor mechanism were adopted to levitate and rotate the rotor, Radial movements of the rotor and rotation are controlled actively by using electromagnets in the stator. Axial movement and tilt of the rotor are restricted by passive stability to simplify the control. The radial gap between the rotor and the stator is 1 mm. A closed-loop circuit filled with water was used to examine basic performance of the pump. Maximum flow rate and pressure head were 8 L/min and 200 mm Hg, respectively. Maximum amplitude of radial displacement of the impeller was 0.15 mm. The impeller could be suspended completely without touching the casing wall during the entire pumping process. Power consumption of the pump was only 9.5 W to produce a flow rate of 5 L/min against a pressure head of 100 mm Hg. We conclude that the pump has sufficient performance for the implantable ventricular assist system., WILEY-BLACKWELL
Artificial Organs, May 2001

Development and chronic in vivo testing of an electrohydraulic totally implantable artificial heart system
Eisuke Tatsumi; Yoshiuki Taenaka; Akihiko Homma; Knihiro Uesho; Tomohiro Nishinaka; Tomonori Tsukiya; Hisateru Takano; Toru Masuzawa; Makoto Nakamura; Kohji Koshiji; Kinji Tsukahara; Katsuya Tsuchimoto; Hideki Wakui, The results of in vivo evaluation of electrohydraulic totally implantable artificial heart (EHTAH) systems were presented. To improve thrombo-resistant property, optimization of blood pump shapes from the hydrodynamic viewpoint were implemented according to the results of a novel flow visualization technique. The EHTAH system demonstrated an excellent anatomic fit and satisfactory in vivo performance represented by the successful sustainment of an animal's blood circulation for over 12 weeks.
American Society of Mechanical Engineers, Bioengineering Division (Publication) BED, 2001

Noninvasive assessment method to determine the anatomic compatibility of an implantable artificial heart system
B Zhang; E Tatsumi; Y Taenaka; H Takano; T Masuzawa, To assess the anatomic compatibility of an artificial heart (AH), we attempted to develop a computer environment that would facilitate a reliable simulation of an AH implanted in the human thorax. A three-dimensional thoracic computer model with a ventricle-resected heart was constructed, by using manually extracted contour points of the aorta, pulmonary artery, atria, atrioventricular valves, diaphragm, and thoracic wall from a set of consecutive CT images. Such a model enabled simulation of an AH implantation by orienting the AH model in it. Error evaluation on CT imaging and contour extraction with a Plexiglas cylindrical phantom showed that the diameter of the extracted phantom contour was approximately 2 mm smaller than its original with a standard deviation of < 0.5 mm. Errors in contour and surface reconstruction could be reduced to far less than 1 mm under constrained conditions. A study on the influence of breathing revealed that variations in some thoracic dimensions between inspiration and expiration could reach 10 mm. In summary, computer simulation of AH implantation is a worthwhile approach with acceptable accuracy, although further considerations of extreme thoracic situations will be required., LIPPINCOTT WILLIAMS & WILKINS
ASAIO JOURNAL, Sep. 2000, [Reviewed]

Magnetically suspended rotary blood pump with radial type combined motor-bearing (jointly authored)
Masuzawa T; Kita T; Matsuda K; Okada Y, A magnetically suspended centrifugal blood pump is being developed with a combined motor-bearing for long-term ventricular assist systems. The combined motor-bearing actively suspends a rotor in a radial direction to deal with radial force unbalance in the pump and rotates the rotor by using the electric magnetic field. Therefore, the pump has no mechanical parts such as bearings of the motor and has a long lifetime. The developed pump consists of a thin rotor with a semi open-type 6 vane impeller and a stator to suspend and rotate the rotor. The rotor has 4-pole permanent magnets on the circumferential surface. The outer diameter and the thickness of the rotor are 60 mm and 8 mm, respectively. Axial movement and tilt of the rotor are restricted by passive stability based on the thin rotor structure. Radial movements of the rotor, such as levitation in radial direction and rotation, are controlled actively by using electric magnets of the stator. The electric magnet coils to produce levitation and rotation forces are constructed on the periphery stator. The p +/- 2-pole algorithm and the synchronous motor mechanism are adopted to levitate and rotate the rotor. The radial gap between the rotor and the stator is 1 mm. A closed-loop circuit filled with water was connected to the developed pump to examine the basic performance of the pump and the magnetic suspension system. Maximum rotational speed, flow rate, and head were 2,800 rpm, 11 L/min, and 270 mm Hg, respectively. The rotor with the impeller could be suspended completely during the entire pumping process. We conclude the pump with the combined motor-bearing has sufficient performance for the blood pump., WILEY-BLACKWELL
Artificial Organs, Jun. 2000

酸素消費量モニタを利用した全人工心臓の流量制御法の開発　　　　　　　　　　　　　　　
中村真人; 本間章彦; 高谷節雄; 大内克洋; 坂本徹; 上所邦広; 巽英介; 妙中義之; 増澤 徹
循環制御, Apr. 2000

Transcutaneous Energy Transmission System for a Totally Implantable Total Artificial Heart - Design and In Vivo Evaluation of the Energy Backup System -
SHIBA K; SHU E; KOSHIJI K; TSUCHIMOTO K; TSUKAHARA K; MASUZAWA T; KAKUTA Y; TATSUMI E; TAENAKA Y; TAKANO H, We have been developing an externally-coupled transcutaneous energy transmission system (ECTETS) for a totally implantable total artificial heart (TITAH) When a patient takes a bath or if some emergency of transcutaneous energy transmission occurs, the energy backup system must switch the energy source from the ECTETS to a rechargeable internal backup battery (RIBB). Then when the transcutaneous energy transmission has been restarted, the energy backup system must switch the energy source from the rechargeable battery to the ECTETS in order to drive TITAH and charge the RIBB. In this study, an energy backup system that can automatically switch energy sources without any discontinuity of the energy supply, was designed and manufactured on an experimental basis. Further, the performance of the energy backup system was evaluated in an in vivo experiment by implanting the secondary coil of the transcutaneous transformer and the RIBB (consisting of a series connection of seven Li⁺ rechargeable batteries) enclosed in a titanous canister in the goat body. As a result, it was found that the switch from the ECTETS to the RIBB requires 100ms and from the RIBB to the ECTETS 50ms. The total efficiency of the ECTETS with the energy backup system was 73-97%, and the temperatures of the implanted devices were less than 40.5°C. It is concluded that the ECTETS with an energy backup system performs adequately., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 15 Feb. 2000

Computational fluid dynamics analysis of a centrifugal blood pump with washout holes
Yuki Tsukamoto; Kazuyuki Ito; Toshio Sawairi; Yoshiaki Konishi; Takashi Yamane; Masahiro Nishida; Toru Masuzawa; Tomonori Tsukiya; Seiko Endo; Yoshiyuki Taenaka, The authors studied avoidance of coagulation occurrence using computational fluid dynamics (CFD) analysis from the fluid dynamical point of view. Concerning centrifugal pumps, blood coagulation sometimes occurs at the region behind the impeller where the flow is generally stagnant. Therefore, we conducted a thorough study with the specimen pump with and without washout holes, mocking up the Nikkiso HPM-15. As the result, the model with washout holes indicated that the fluid rotates rapidly at the vicinity of the shaft and generates washout effects near the stationary rear casing. On the other hand, the model without washout holes showed that fluid cannot be quickly shipped out of the area behind the impeller and rotates mildly around the shaft. To clarify the moving relations between the impeller and the fluid, validation studies by comparing the results of CFD analysis and flow visualization experiments are ongoing
thus far, the studies show that CFD results are similar to the results from flow visualization experiments.
Artificial Organs, 2000

Progress of an electrohydraulic total artificial heart system with a separate energy converter (jointly authored)
Masuzawa T; Tatsumi E; Taenaka Y; Nakamura M; Endo S; Takano H; Koshiji K; Fukui Y; Murai T; Tsukahara K, We have been developing an electrohydraulic total artificial heart (EHTAH) system. The system consists of diaphragm blood pumps, an abdominally placed energy converter, an internal controller, a transcutaneous energy transfer (TET) system, a transcutaneous optical information transfer system, and internal and external lithium-ion (Li-ion) batteries. The energy converter was optimized to obtain better oil transfer. Maximum cardiac output and efficiency of the EHTAH were increased from 8 L/min to 10 L/min and from 10% to 12%, respectively. The volume of the energy converter was reduced from 280 to 210 ml. The pumping unit was successfully implanted in 68-85 kg calves without anatomic problems, and the calves survived up to 10 days with good circulatory results. The maximum temperature rise of the implanted energy converter was only 1 degrees C. Stable performance of the TET system was confirmed in goats for more than 1 month. DC-DC energy transfer efficiency with 20 W of energy transmission remained within the range of 80% to 85%, and no significant temperature rise was observed in the implanted circuit. The internal Li-ion battery was also evaluated in a goat, and the maximum temperature rise during the charging period was 1.5 degrees C, while the charging and discharging times were 72 and 58 min, respectively. We conclude that our system has progressed in its development as a practical implantable system., LIPPINCOTT WILLIAMS & WILKINS
ASAIO Journal, Sep. 1999

Control of a total artificial heart using mixed venous oxygen saturation
M Nakamura; T Masuzawa; E Tatsumi; Y Taenaka; T Ohno; T Nakamura; B Zhang; Y Kakuta; T Nakatani; H Takano, We developed a control of the total artificial heart (TAH) using mixed venous oxygen saturation (SvO(2)). With this method, the TAH output was controlled by automatically adjusting drive parameters in response to changes in measured SvO(2). The feasibility and validity of this method were evaluated in a series of treadmill exercise tests using a calf implanted with a pneumatic TAH. The cardiac output (CO) and SvO(2) were measured with an ultrasonic flowmeter and an oximetric catheter, respectively. The calf performed graded exercise under a fixed drive control mode (fixed mode), in which the drive parameters were unchanged throughout the treadmill test and under the SvO(2) based control mode (SvO(2) mode). The calf could go to Stage 6 in both modes, but the maximal oxygen consumption in the SvO(2) mode was 1.5 times as large as that of the fixed mode. Compared with the fixed mode, CO was increased effectively in the SvO(2) mode, and the capacity for exercise was augmented. When considering the relationship between oxygen consumption and oxygen delivery, it was revealed that the CO in the SvO(2) mode responded more adequately to the recipient's oxygen demand than that in the fixed mode. We conclude that this SvO(2) based control method is feasible and physiologically effective., LIPPINCOTT WILLIAMS & WILKINS
ASAIO JOURNAL, Sep. 1999

Development of design methods for a centrifugal blood pump with a fluid dynamic approach : Results in hemolysis tests (jointly authored)
Masuzawa T; Tsukiya T; Endo S; Tatsumi E; Taenaka Y; Takano H; Yamane T; Nishida M; Asztalos B; et al, The purpose of this study was to examine the relationship between local flow conditions and the hemolysis level by integrating hemolysis tests, flow visualization, and computational fluid dynamics to establish practical design criteria for centrifugal blood pumps with lower levels of hemolysis. The Nikkiso centrifugal blood pump was used as a standard model, and pumps with different values of 3 geometrical parameters were tested. The studied parameters were the radial gap between the outer edge of the impeller vane and the casing wall, the position of the outlet port, and the discharge angle of the impeller vane. The effect of a narrow radial gap on hemolysis was consistent with no evidence that the outlet port position or the vane discharge angle affected blood trauma in so far as the Nikkiso centrifugal blood pump was concerned. The radial gap should be considered as a design parameter of a centrifugal blood pump to reduce blood trauma., WILEY-BLACKWELL
Artificial Organs, Aug. 1999

Three-dimensional thoracic modeling for an anatomical compatibility study of the implantable total artificial heart
B Zhang; T Masuzawa; E Tatsumi; Y Taenaka; C Uyama; H Takano; M Takamiya, Anatomical compatibility with the thoracic cavity is important in developing a completely implantable total artificial heart (TAH). The purpose of this study was to examine the optimal morphology of our TAH and to develop a computer implantation simulation environment for preoperational discussion. As the first stage, we constructed a prototype simulation system by creating a 3-D surface model of a thoracic cavity and one of a TAH. In this system, the thoracic surface model, composed of the aorta, pulmonary artery, ventricle resected heart, diaphragm, and thoracic wall, was created based on the organ contours extracted from electrocardiogram (ECG)-synchronized ultrafast computer tomographic images. The accuracy of the thoracic model was discussed using a phantom. The fitting study can be performed on the computer with the model of the thorax and that of the TAH. In the future, construction of a database for the thoracic cavities of heart failure patients is planned to improve the morphology of the TAH., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, Mar. 1999

The development of a control method for a total artificial heart using mixed venous oxygen saturation
M Nakamura; T Masuzawa; E Tatsumi; Y Taenaka; T Nakamura; B Zhang; T Nakatani; H Takano; T Ohno, For physiological control of a total artificial heart (TAH), applying mixed venous oxygen saturation (Svo(2)) as a parameter for TAH control is a promising approach regarding sensitivity to the recipient's oxygen demand and the practical possibility of continuous monitoring using near infrared rays through transparent blood pump housings. To develop a control method for the TAH using Svo(2), the relationship between Svo(2) and cardiac output (CO) was investigated in a normal calf, and a control algorithm was developed based on this correlation. Then the feasibility of this method (Svo(2) mode) was evaluated in a calf implanted with a pneumatic TAH and compared with the fixed drive control mode (fixed mode) in which the drive parameters were unchanged. The calf performed a graded exercise test in both modes. The CO was effectively increased from 7.3 to 13.0 L/min in the Svo(2) mode, and the capacity for exercise was augmented compared to the fixed mode. We conclude that this Svo(2) mode is feasible and may be effectively applied in TAH control., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, Mar. 1999

In vivo evaluation of the national cardiovascular center electrohydraulic total artificial heart
E Tatsumi; T Masuzawa; M Nakamura; Y Taenaka; T Nishimura; S Endo; B Zhang; Y Kakuta; M Nakata; T Nakamura; T Nishinaka; H Takano; K Tsukahara; K Tsuchimoto, We have been developing an electrohydraulic total artificial heart system. The system comprises an intrathoracic pumping unit composed of diaphragm type ellipsoidal blood pumps and an energy converter in addition to an electronics unit. The in vivo performance of the pumping unit was evaluated in a series of animal implantations with 3 calves weighing 62-85 kg. An interatrial shunt 4.5 mm in diameter was made in the atrial septum to compensate left-right imbalance. Two calves died early postoperatively, one of external controller power failure and the other of interatrial shunt stenosis due to thrombus formation. One calf, however, survived over 10 days under stable circulatory conditions. No abnormality was found in the oxygen metabolic condition or in major organ functions. The generation and dissipation of heat from the device was acceptable. This animal died of device malfunction caused by energy converter bearing breakdown. The device demonstrated a good anatomic fit without compromising the great vessels and adjacent tissues. It is concluded that the pumping unit has a sufficient in vivo basic performance although appropriate countermeasures are to be implemented against the detected problems concerning mechanical durability and interatrial shunt patency., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, Mar. 1999

混合静脈血酸素飽和度に基づいた全人工心臓流量制御法の開発　　　　　　　　　　　　　　　
中村真人; 巽 英介; 増澤 徹; 妙中義之; 大野 孝; 上所邦広; 角田幸秀; 張 斌; 中村知道
人工臓器, Mar. 1999

Transcutaneous energy transmission system for a totally implantable artificial heart. Charging control of rechargeable internal backup battery and driving a TIAH.
Shiba K; Honda H; Shu E; Koshiji K; Tsuchimoto K; Tsukahara K; Masuzawa T; Tatsumi E; Taenaka Y; Takano H, A rechargeable internal backup battery (RIBB) for a totally implantable artificial heart (TIAH) is required as a backup for the transcutaneous energy transmission system (TETS). We have been developing an externally coupled transcutaneous energy transmission system (ECTETS) as a TETS. This paper reports on the use of the ECTETS to simultaneously power a TIAH and Li-ion rechargeable internal backup batteries as a RIBB. A charge-control circuit consisted of a constant-current and constant-voltage circuit created on an experimental basis, and a push-pull circuit was used as the switching circuit for the ECTETS. The energy from the ECTETS was simultaneously supplied to a TIAH consuming a power of 20 W, simulated by an electronic load simulator, and the charger of the RIBB. As a result, it was found that the time required to charge up was 102 minutes, the outnput power and the DC-to-DC energy transmission efficiency of the ECTETS were 22-35 W and 81-84%, respectively, and the efficiency of the charge control circuit was 91-93%. It is concluded that charging was safely, quickly and efficiently performed, and the ECTETS showed a high enough level of performance to simultaneously power the TIAH and the charger., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 1999

Investigation of a transcutaneous transformer with regard to high-power transmission for a totally implantable artificial heart.
Shiba K; Shu E; Koshiji K; Fujiwara O; Nakamura Y; Masuzawa T; Tatsumi E; Taenaka Y; Takano H, When simultaneously charging a rechargeable internal backup battery and driving a totally implantable artificial heart (TIAH), we must transcutaneously transmit a power of more than 40 W from outside of the body. In this paper, the materials, shape, and section area of the ferrite core used in an externally-coupled transcutaneous energy transmission system (ECTETS) were investigat ed with regard to high-power transmission.A material of low energy loss and temperature dependency in the range of 25-36°C was selected for the ferrite core, and this ferrite core was designed to be shaped like a donut from the viewpoint of easy attachment to the body. Three kinds of transformers (section areas of T1: 126 mm2, T2: 189 mm2 and T3: 242 mm2, respectively) were made experimentally, and the DC-to-DC energy transmission efficiency (with a transmission power of 40 W) of the ECTETS with each transformer was measured in an in vitro experiment. As a result, it was found that the efficiencies when using T2 and T3 were improved by more than 15%, and the temperature rises were suppressed by 50% compared with the conventional transformer. Although acute and the 2-week chronic animal experiments were also conducted with goats, there were no noticeable differences in the results compared with the in vitro experiment. In the animal experiments, the temperature on the ferrite core surface was suppressed to less than 42°C.It is concluded that the ferrite core with a section area of more than 189 mm2 can be used as an externally coupled transcutaneous transformer.KEYWO, JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 1999

Computational fluid dynamics analysis to establish the design process of a centrifugal blood pump: Second report
Yuki Miyazoe; Toshio Sawairi; Kazuyuki Ito; Yoshiaki Konishi; Takashi Yamane; Masahiro Nishida; Balazs Asztalos; Toru Masuzawa; Tomonori Tsukiya; Seiko Endo; Yoshiyuki Taenaka, To establish an efficient design process for centrifugal blood pumps, the results of computational fluid dynamics (CFD) analysis were compared to the results of flow visualization tests and hemolysis tests, using the Nikkiso centrifugal blood pump. CFD analysis revealed that the radial gap greatly affected the shear stress in the outlet diffuser. The hemolysis study also indicated a similar tendency. To see the flow behind the impeller, we conducted a comparative study between models with and without washout holes using the CFD technique. CFD analysis indicated that flow and pressure distributions behind the impeller were different between both models, and a particle was observed to remain longer behind the impeller in the model without washout holes. In the future, CFD analysis could be a useful tool for developing blood pumps in comparison to flow visualization tests and hemolysis tests.
Artificial Organs, 1999

Flow visualization study to improve hemocompatibility of a centrifugal blood pump
Masahiro Nishida; Balázs Asztalos; Takashi Yamane; Toru Masuzawa; Tomonori Tsukiya; Seiko Endo; Yoshiyuki Taenaka; Yuki Miyazoe; Kazuyuki Ito; Yoshiaki Konishi, A correlation study was conducted among quantitative flow visualization analysis, computational fluid dynamic analysis, and hemolysis tests regarding the flow in a centrifugal blood pump to prevent hemolysis. Particular attention was paid to the effect of the impeller/casing gap widths on the flow in the volute and in the outlet. Flow vector maps were obtained for 250% scaled-up models with various geometries, using an argon ion laser light sheet, a high speed video camera, and particle tracking velocimetry. In terms of the results, in the small radial gap model, high shear occurred near the inside wall of the outlet and stagnation near the outside wall of the outlet whereas the standard model maintained smooth flow and low shear. The small radial gap model showed a lower head and greater hemolysis than the standard model. This head decrease could be partly restored by relocating the outlet position
however, the hemolysis level hardly decreased. From these results, it was found that the small radial gap itself is important. It was also confirmed by detailed flow visualization and simple laminar shear analysis near the wall that the small radial gap caused a wider high shear layer (110- 120 μm) than the standard model (~80 μm). In the small radial gap model, the high shear layer in the outlet (~50 μm) is much narrower than that in the volute. Flow visualization together with the aid of computational fluid dynamic analysis would be useful to eliminate the causes of hemolysis.
Artificial Organs, 1999

Selection of a rechargeable internal back-up battery for a totally implantable artificial heart
Hiroyuki Honda; Kenji Shiba; Eimei Shu; Kohji Koshiji; Takeji Murai; Tomomichi Nakamura; Toru Masuzawa; Eisuke Tatsumi; Yoshiyuki Taenaka; Hisateru Takano, Three kinds of rechargeable batteries, NiCd, NiMH, and Li+, were compared for the purpose of selecting the most appropriate battery for use in a Rechargeable Internal Back-up Battery (RIBB) unit for a Totally Implantable Artificial Heart. Batteries of each kind were connected in series to obtain the required driving voltage of 24 V. The NiCd and NiMH batteries were charged by a constant current of 1 C, and the Li+ batteries were charged first by a constant current of 1 C and later by a constant voltage of 28.7 V. All three types of batteries were discharged using a dummy electronic pulsatile load consuming 20 W of power. The tests showed that the Li+ batteries were capable of supplying the required energy for more than 60 minutes. The Li+ batteries had a specific energy of 121.5 Wh/kg, which was more than 3× that of the NiCd and NiMH, and an energy density of 282.5 Wh/L more than double that of the other two. In addition, the Li+ batteries recorded the least temperature rise during charging and discharging. The results of our tests conclusively showed that the Li+ battery is the best among the three for use in an RIBB from the viewpoint of energy density and temperature rise., Lippincott-Raven Publ
ASAIO Journal, 1999, [Reviewed]

A transcutaneous energy transmission system with rechargeable internal back-up battery for a totally implantable total artificial heart
Kenji Shiba; Eimei Shu; Kohji Koshiji; Kinji Tsukahara; Tomomichi Nakamura; Toru Masuzawa; Eisuke Tatsumi; Yoshiyuki Taenaka; Hisateru Takano, We have been developing an externally coupled transcutaneous energy transmission system (ECTETS) for a totally implantable total artificial heart (TITAH). When the ECTETS is unable to supply the energy to drive the TITAH from outside the body, a rechargeable internal back-up battery (RIBB) implanted inside the body is used as a back-up to supply the required energy. This paper reports on the performance characteristics of our ECTETS with an RIBB. In this study, a lithium-ion (Li+) secondary battery was used as the RIBB. The transcutaneous energy transmission and the charging control characteristics of the ECTETS, while simultaneously supplying energy to the TITAH and the RIBB, were evaluated in an in vitro experiment. The output power and transmission efficiency of the ECTETS operating in this mode were found to vary from 20 W to 34 W and from 84% to 71%, respectively. It was also found that a sufficient power of more than 20 w could be supplied to the TITAH. The time needed to fully charge the RIBB was 117 minutes, and a fully charged RIBB could drive the TITAH, consuming 20 W for 62 minutes. It may, therefore, reasonably be concluded that the ECTETS with the RIBB is sufficient to drive the TITAH., Lippincott-Raven Publ
ASAIO Journal, 1999, [Reviewed]

Cardiac autonomic nervous function during long-term nonpulsatile left heart bypass
Tomohiro Nishinaka; Eisuke Tatsumi; Takashi Nishimura; Yoshiyuki Taenaka; Toru Masuzawa; Masako Nakata; Hisateru Takano; Hitoshi Koyanagi, We investigated the changes in cardiac autonomic nervous activities during long-term nonpulsatile left heart bypass (NLHB) by analyzing heart rate variability. A pulsatile ventricular assist device was installed in 3 goats, and pulsatile left heart bypass (PLHB) was conducted for 2 weeks. Then, NLHB was maintained for the following 4 weeks. The segmental data of the R-R intervals (R-Rs) was analyzed by maximum entropy spectral analysis. Changes in evaluated parameters from the last week of PLHB to the 4th week of NLHB were as follows: the mean R-Rs increased from 511 ms to 692 ms
the coefficient of variation of R-R increased from 10.2 to 14.1%
the power of the low frequency band (LF) increased from 747 ms2 to 2,855 ms2
the power of the high frequency band (HF) increased from 512 ms2 to 1,270 ms2
and the ratio of LF to HF increased from 2.6 to 6.5. These results indicated that the cardiac autonomic nervous activity, both sympathetic and parasympathetic, increased during long-term NLHB.
Artificial Organs, 1999, [Reviewed]

Augmentative effect of pulsatility on the wall shear stress in tube flow
Masako Nakata; Eisuke Tatsumi; Tomonori Tsukiya; Yoshiyuki Taenaka; Takashi Nishimura; Tomohiro Nishinaka; Hisateru Takano; Toru Masuzawa; Kenkichi Ohba, Wall shear stress (WSS) has been considered to play an important role in the physiological and metabolic functions of the vascular endothelial cells. We investigated the effects of the pulse rate and the maximum flow rate on the WSS to clarify the influence of pulsatility. Water was perfused in a 1/2 inch transparent straight cylinder with a nonpulsatile centrifugal pump and a pulsatile pneumatic ventricular assist device (VAD). In nonpulsatile flow (NF), the flow rate was changed 1 to 6 L/min by 1 L/min increments to obtain standard values of WSS at each flow rate. In pulsatile flow (PF), the pulse rate was controlled at 40, 60, and 80 bpm, and the maximum flow rate was varied from 3.3 to 12.0 L/min while the mean flow rate was kept at 3 L/min. The WSS was estimated from the velocity profile at measuring points using the laser illuminated fluorescence method. In NF, the WSS was 12.0 dyne/cm2 at 3 L/min and 33.0 dyne/cm2 at 6 L/min. In PF, the pulse rate change with the same mean, and the maximum flow rate did not affect WSS. On the other hand, the increase in the maximum flow rate at the constant mean flow rate of 3 L/min augmented the mean WSS from 13.1 to 32.9 dyne/cm2. We concluded that the maximum flow rate exerted a substantial augmentative effect on WSS, and the maximum flow rate was a dominant factor of pulsatility in this effect.
Artificial Organs, 1999, [Reviewed]

Diminished vasoconstrictive function caused by long-term nonpulsatile left heart bypass
Takashi Nishimura; Eisuke Tatsumi; Tomohiro Nishinaka; Yoshiyuki Taenaka; Toru Masuzawa; Masako Nakata; Hisateru Takano, We investigated the functional changes of the systemic vascular system due to prolonged nonpulsatile left heart bypass (NPLHB). Three adult goats underwent pulsatile left heart bypass (PLHB). Two weeks later the PLHB was changed to the NPLHB, which was conducted for 4 weeks. The aortic pulse pressure was 39 and 16 mm Hg during the PLHB and NPLHB, respectively. Systemic vascular resistance (SVR) and the plasma norepinephrine level were measured at the end of PLHB (PUL), and in the 1st, 2nd, 3rd, and 4th weeks of NPLHB (NP1w, NP2w, NP3w, and NP4w). At each point, 1 μg/kg norepinephrine was injected, and the elevation of the SVR (ΔSVR) was calculated. The SVR and the plasma norepinephrine level did not change significantly during the entire course. However, ΔSVR decreased during NPLHB and became significantly lower at NP3w and NP4w than that at PUL (NP3w: 839 ± 164, NP4w: 746 ± 268, and PUL: 1,239 ±324 dyne · s · cm-5). These results strongly indicated that prolonged NPLHB significantly diminished the constrictive function of the vascular system.
Artificial Organs, 1999, [Reviewed]

Quantitative evaluation of humoral conditions under various pulmonary blood flow during venoarterial bypass
TAKEWA Y.; TATSUMI E.; TAENAKA Y.; NAKATANI T.; MASUZAWA T.; NISHIMURA T.; NAKAMURA M.; ENDO S.; TAKANO H.; TANAKA S., Hemodynamic and humoral conditions under various pulmonary blood flow during venoarterial bypass (VAB) were quantitatively investigated in a series of chronic animal experiments. A biventricular bypass system was installed in 6 adult goats weighing 50.0±1.1 kg. Two weeks later the extracorporeal circuitry was changed to VAB without anesthesia. The PAF was reduced stepwise from 100% to 50, 25, 10 and 0% of total systemic flow. The mean aortic pressure (mAoP) and systemic vascular resistance (SVR) decreased in proportion to the decrease in PAF and caused a sort of shock state at 0% PAF. The prostaglandin E² (PGE²) concentration increased following the decrease in PAF from 100 to 0%. The renin-angiotensin system increased in proportion to the decrease in PAF. In contrast, the catecholamines concentrations did not change appreciably even at 10% PAF, but were markedly elevated at 0% PAF. The antidiuretic hormone level similarly changed. In conclusion, decrease in PAF during VAB exerts significant effects on the hemodynamics. The changes in the levels of vasodilators, especially PGE², may play a substantial role in the decrease in SVR, whereas changes in vasoconstrictors are likely to be a secondary reaction to the decrease in mAoP., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 15 Aug. 1998

Prolonged nonpulsatile left heart bypass with reduced systemic pulse pressure causes morphological changes in the aortic wall
T Nishimura; E Tatsumi; S Takaichi; Y Taenaka; Y Wakisaka; T Nakatani; T Masuzawa; Y Takewa; M Nakamura; S Endo; M Nakata; H Takano, We investigated the morphological changes in the aorta due to reduced systemic pulse pressure in prolonged nonpulsatile left heart bypass (LHB). Nineteen adult goats were divided into 3 groups, the nonpulsatile group in which nonpulsatile LHB was conducted, the pulsatile group in which pulsatile LHB was conducted, and the control group used as the normal control. The average aortic pulse pressures were 12, 47, and 37 mm Hg, respectively. The descending aorta was subjected to morphological examination. In the nonpulsatile group, the wall was significantly thinner, and the volume ratio of smooth muscle cells (SMCs) was much lower. In terms of the SMC type classification, the proportion of SMCs with low activity and low contractility was higher, and the cell density of the SMCs was increased compared to those in the other groups. These results indicate that prolonged nonpulsatile LHB causes morphological atrophic changes in the aorta., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, May 1998, [Reviewed]

Development of design methods of a centrifugal blood pump with in vitro tests, flow visualization, and computational fluid dynamics: Results in hemolysis tests
K Takiura; T Masuzawa; S Endo; Y Wakisaka; E Tatsumi; Y Taenaka; H Takano; T Yamane; M Nishida; B Asztalos; Y Konishi; Y Miyazoe; K Ito, There are few established engineering guidelines aimed at reducing hemolysis for the design of centrifugal blood pumps. In this study, a fluid dynamic approach was applied to investigate hemolysis in centrifugal pumps. Three different strategies were integrated to examine the relationship between hemolysis and flow patterns. Hemolytic performances were evaluated in in vitro tests and compared with the flow patterns analyzed by flow visualization and computational fluid dynamic (CFD). Then our group tried to establish engineering guidelines to reduce hemolysis in the development of centrifugal blood pumps. The commercially available Nikkiso centrifugal blood pump (HPM-15) was used as a standard, and the dimensions of 2 types of gaps between the impeller and the casing, the axial and the radial gap, were varied. Four impellers with different vane outlet angles were also prepared and tested. Representative results of the hemolysis tests were as follows: The axial gaps of 0.5, 1.0, and 1.5 mm resulted in normalized index of hemolysis (NIH) values of 0.0028, 0.0013 and 0.0008 g/100 L, respectively. The radial gaps of 0.5 and 1.5 mm resulted in NIH values of 0.0012 and 0.0008 g/100 L, respectively. The backward type vane and the standard one resulted in NIH values of 0.0013 and 0.0002 g/100 L, respectively. These results revealed that small gaps led to more hemolysis and that the backward type vane caused more hemolysis, Therefore, the design parameters of centrifugal blood pumps could affect their hemolytic performances. In flow visualization tests, vortices around the impeller outer tip and tongue region were observed, and their patterns varied with the dimensions of the gaps. CFD analysis also predicted high shear stress consistent with the results of the hemolysis tests. Further investigation of the regional flow patterns is needed to discuss the cause of the hemolysis in centrifugal blood pumps., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, May 1998

LONG-TERM EVALUATION OF A HEPARIN BONDED ARTIFICIAL LUNG -CONTINUOUS USE UP TO 36 DAYS
TAKEWA Y.; TATSUMI E.; TAENAKA Y.; NAKATANI T.; MASUZAWA T.; NISHIMURA T.; NAKAMURA M.; ENDO S.; TAKANO H.; TANAKA H., The long-term evaluation of a heparin bonded artificial lung (AL) was performed with chronic animal experiments. The AL developed in our institution was made with polyolefin hollow fiber membrane where micropores are blind-ended to prevent serum leakage. The blood contacting surface is treated with newly developed covalently heparin-bonding technique to provide good antithrombogenicity. Six goats weighing 50±1.1 kg were perfused with the AL and a pneumatic ventricular assist device in a venoarterial bypass circuit for up to 36 days (17±14 days). Serum leakage was completely prevented in all the devices throughout the experiments. Minimum amounts of heparin (2-3 U/kg/h) were used for systemic anticoagulation. Only in one case the thrombotic complication related to the AL was observed The gas exchange performance was satisfactorily demonstrated for up to 36 days. Blood components and coagulation factors were maintained within acceptable limits. The blood contacting surfaces after the experiment were found almost free of thrombus, while in 3 cases which were perfused more than 2 weeks, thrombus formation was observed mainly on the margin of the inflow side. These results indicate that our AL can be used for prolonged ECMO, although further improvement in thromboresistant properties should be achieved., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 15 Apr. 1998

EXTERNALLY-COUPLED TRANSCUTANEOUS ENERGY TRANSMISSION SYSTEM FOR A TOTALLY IMPLANTABLE ARTIFICIAL HEART-IN VITRO AND IN VIVO ESTIMATIONS FROM THE VIEWPOINT OF ELECTRICAL ENGINEERING
SHIBA K.; SHU E.; KOSHIJI K.; TSUKAHARA K.; TSUCHIMOTO K.; OHU-MI T.; NAKAMURA T.; ENDO S.; MASUZAWA T.; TATSUMI E.; TAENAKA Y.; TAKANO H., Externally-coupled transcutaneous energy transmission system(ECTETS) which has DC to DC energy transmission efficiency of more than 86% in in vitro experiment is very useful for a totally implantable artificial heart. In in vivo experiment of the ECTETS with the internal coil and the rectifier circuit implanted under the skin of a living goat, the DC to DC energy transmission efficiencies were measured using electronic load simulator(ELS) and implantable electrohydraulic total artificial heart(EHTAH) as a load, respectively. As a result, the DC to DC energy transmission efficiency of the ECTETS with the ELS was 81.4% in operation at the output power of 19.2W. It was found that the lowering of the efficiency compared with that in in vitro experiment was caused by the increase in stray capacitance between the windings of the external coil by applying liquid to that surface for sterilization. In driving the EHTAH at the heart rate of 70bpm, the driving power was 20.7W, the pump output flow was 6.2L/min, the DC to DC energy transmission efficiency was 82.1%, and the surface temperature of the internal circuit was less than 40.5°C. In conclusion, the ECTETS had good performance in in vivo experiment., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, Apr. 1998, [Reviewed]

エレクトロハイドローリック方式全人工心臓の慢性動物実験による生体内評価
巽 英介; 増澤 徹; 妙中義之; 中村真人; 遠藤誠子; 西村 隆; 孫 領相; 大野 孝; 瀧浦晃基; 武輪能明; 中谷武嗣; 高野久輝, In vivo performance of an electrohydraulic total artificial heart (EHTAH) system was evaluated for 10 days in a chronic animal experiment. The system consisting of blood pumps and an energy converter was implanted in a 62 kg calf, and was actuated by an external controller though a percutaneous lead at a fixed rate of 85 bpm. A shunt hole of 4.5 mm in diameter was made in the atrial septum to redistribute imbalanced left and right atrial pressures and volumes. During the experiment, the animal's circulation was stably maintained by the EHTAH with an adequate left-right balance. Oxygen metabolic condition was kept favorable at any time of the experiment. No abnormality was found in major organ functions. Generation and dissipation of heat from the device was also acceptable. There occurred, however, mechanical failures including hydraulic oil leakage detected on the 9th day and bearing breakdown resulting in device malfunction on the 10th day. The device demonstrated good anatomic fit at autopsy, as well as at implantation, without compromising the great vessels and adjacent tissues. It is concluded that the EHTAH system has a sufficient in vivo basic performance, although appropriate measures are to be implemented against the mechanical problems detected in the present study., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Apr. 1998

可視化解析による全人工心臓用血液ポンプ室内流れの検討　　　　　　　　　　　　　　　
中田雅子; 増澤 徹; 巽 英介; 瀧浦晃基; 妙中義之; 高野久輝; 大場謙吉; 土本勝也; 塚原金二; 大海武晴
人工臓器, Apr. 1998

体内完全埋込型人工心臓に用いる経皮エネルギー伝送ユニットの生体適合性及び実用性の評価－体内埋込時の温度特性とエネルギー伝送効率の検討－
中村知道; 増澤 徹; 遠藤誠子; 角田幸秀; 巽 英介; 妙中義之; 高野久輝; 柴 建次; 越地耕二, The biocompatibilty and practicality of the transcutaneous energy transmission unit(PEI) for the totally implantable artificial heart system were evaluated m in vitro and in vivo experiments. The distribution of the surface temperature on an internal rectifier circuit was investigated by using a thermography camera in the air. We studied thermal characteristics and energy transfer efficiency of the implanted TET system with a goat weighing of 44kg. An energy of 24W was transferred through skin with the TET system. The surface temperature of the rectifier circuit the external coil, and the energy transmission efficiency were measured for one month. A treadmill exercise best at a speed of 2km/h was carried out to investigate the influence of the body movement on the energy transmission efficiency of the TET system. Abnormal high temperature spot on the TET system was not observed, and the temperature on the implanted system slid not rise and stayed with the same level of the body temperature. The energy transfer efficiency was 80-85% and no change of the efficiency was observed on the treadmill exercise test. As a result sufficient practicality and biocompatibilty of the TET stem were confirmed., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Apr. 1998

電気油圧式全人工心臓の放熱特性に関する検討
遠藤誠子; 増澤 徹; 巽 英介; 妙中義之; 中谷武嗣; 大野 孝; 脇坂佳成; 西村 隆; 武輪能明; 中村真人; 瀧浦晃基; 孫 領相; 高野久輝
人工臓器, Feb. 1998

完全置換型人工心臓装着後の循環血液量の変化と液性因子の検討
中村真人; 巽 英介; 増澤 徹; 大野 孝; 妙中義之; 瀧浦晃基; 孫 領相; 遠藤誠子; 西村 隆; 武輪能明; 脇坂佳成; 中谷武嗣; 高野久輝, The early changes in circulating blood volume (CBV) after implantation of total artificial heart (TAR) were investigated in conjunction with the changes in volume regulating humoral factors (VHFs). CBV and VHFs were periodically evaluated in three calves implanted with an Electrohydraulic or pneumatic TAH and a control calf. The CBV significantly increased in all of the TAH implanted calves, (to 111-155% of the preoperative levels) from early postoperative stage. No consistent decrease in ANP level or consistent increase in ADH level was not observed in the TAH animals, indicating neither ANP nor ADH directly caused the increase of CBV. Renin-angiotensin system were activated in two out of three TAR-implanted animals, suggesting that the implantation of TAR did not always activate the resin-angiotensin system, although there is possible interaction between the CBV and this system. In summary, the CBV increased in the early stage after TAH implantation, and the accompanying changes in VHFs seemed to be not a primary cause of but a secondary response to the increase of CBV, JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Feb. 1998

心房間シャントによる電気油圧駆動方式全人工心臓システムの左右心拍出量差代償に関する研究
巽 英介; 中村真人; 増澤 徹; 妙中義之; 孫 領相; 中田雅子; 大野 孝; 遠藤誠子; 西村 隆; 武輪能明; 中谷武嗣; 高野久輝, We evaluated the basic performance of an interatrial shunt (IAS), which was made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in proportion to the amount of bronchial flow and the size of the IAS. The IAS of 4.4mm in diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in our IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4±1mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. We conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system, JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Feb. 1998

Flow visualization as a complementary tool to hemolysis testing in the development of centrifugal blood pumps
Takashi Yamane; Balázs Asztalos; Masahiro Nishida; Toru Masuzawa; Koki Takiura; Yoshiyuki Taenaka; Yoshiaki Konishi; Yuki Miyazoe; Kazuyuki Ito, With a 250% scaled-up pump model, high speed video camera, and argon ion laser light sheet, flow patterns related to hemolysis were visualized and analyzed with 4 frame particle tracking software. Different flow patterns and shear distributions were clarified by flow visualization for pumps modified to have different hemolysis levels. A combination of in vitro hemolysis tests, flow visualization, and CFD analysis suggested a close relationship between hemolysis and high shear caused by small impeller/casing gaps. Because arbitrary cross sections can be illuminated by laser light sheet, flow visualization is a useful tool in finding locations related to hemolysis in the design process of rotary blood pumps.
Artificial Organs, 1998

In vitro and in vivo evaluation on heat dissipation of electrohydraulic total artificial heart
Seiko Endo; Toru Masuzawa; Eisuke Tatsumi; Yoshiyuki Taenaka; Takeshi Nakatani; Takasi Ohno; Yoshinari Wakisaka; Takashi Nishimura; Yoshiaki Takewa; Makoto Nakamura; Koki Takiura; Young Sang Sohn; Hisateru Takano, We evaluated the heat transfer characteristics of an electrohydraulic total artificial heart (EH-TAH) that have been developed at our institute. In two in vitro experiments, the heat dissipation way of the TAH was investigated. First, we simulated heat transfer of the calf circulation by using a heat exchanger. The amount of heat dissipating directly from the TAH surface and that to the blood chamber were estimated to be almost the same. Second, the temperature of the actuator examined with thermography was found to be almost uniform, and no prominent high temperature area was observed. In an in vivo study, the TAH was implanted in a calf weighing 62 kg for 10 days. The input power to the device was 18 ± 2 W, the temperature of the actuator- tissue contacting surface was 39-41 °C. This slight temperature elevation was thought to be attributable to the heat dissipation to the blood. Upon histological study of the chest wall and the lung in contact with the actuator, vascularized connective tissue enveloped were observed and unfavorable side effects such as tissue necrosis were not observed. These results suggest that the thermal effect of this system is acceptable at this input power.
Japanese Journal of Artificial Organs, 1998

Transcutaneous optical telemetry system with infrared laser diode
Katsushige Inoue; Kenji Shiba; Eimei Shu; Kohji Koshiji; Kinji Tsukahara; Takeharu Oh-Umi; Toru Masuzawa; Eisuke Tatsumi; Yoshiyuki Taenaka; Hisateru Takano, A transcutaneous telemetry system is indispensable when monitoring and controlling the operation of an artificial heart totally implanted inside the body. A telemetry system using light is more useful than radio waves from the viewpoint of electromagnetic interference and power consumption. In this report, a transcutaneous optical coupler consisting of an infrared laser diode (LD) and a PIN photodiode (PINPD) was evaluated, and the transcutaneous optical coupling and information transmission characteristics were evaluated in in vitro experiments. The wavelength and directional angle of the LD used were 830 nm and 9.5 degrees, respectively. With regard to the directional angle of PINPD, the authors found that a PINPD with a larger directional angle allowed for more deviation between the axes optical axes of the LD and the PINPD. It was also found that the transcutaneous coupler had an optimum distance for the permissible deviation to be maximized. The information signals modulated by the phase shift keying (PSK) were transmitted at a rate of 9,600 bps through goat skin 4 mm thick, and demodulated by the phase locked loop (PLL) on the receiving side. As a result, the information signals were demodulated without any errors in deviation within 10.5 mm at a distance of 11 mm. In conclusion, the transcutaneous optical telemetry system using an infrared LD has sufficient characteristics to monitor and control the operation of an artificial heart totally implanted inside the body., Lippincott-Raven Publ
ASAIO Journal, 1998, [Reviewed]

Characterization and optimization of the flow pattern inside a diaphragm blood pump based on flow visualization techniques
Masako Nakata; Toru Masuzawa; Eisuke Tatsumi; Yoshiyuki Taenaka; Takashi Nishimura; Tomonori Tsukiya; Hisateru Takano; Katsuya Tsuchimoto; Kenkichi Ohba, We applied two different flow visualization techniques to obtain detailed information on the inside flow of the diaphragm blood pump of our electrohydraulic total artificial heart system to determine the optimum washout effect that would result in better antithrombogenicity. Major orifice directions of the inflow and outflow Bjork-Shiley valves of the left blood pump were independently changed to create 17 varied patterns. The character and velocity of the main flow at the diaphragm-housing junction were acquired using a laser light sheet method with polyethylene tracers. Wall shear flow, a major factor governing washout in the blood pump, was estimated by a newly developed paint erosion method. In this method, quantitative evaluation for an index of washout effect was made by calculating the residual ratio of the paint on the blood pump inner surface at 30 sec of pumping. When a single circular flow was consistently observed by the laser light sheet method, the paint residual ratio become low, indicating washout was relatively good. At the lowest paint residual ratio, the center of the circular flow observed by the laser light sheet method was located at the geometric center of the blood chamber. In conclusion, the flow pattern inside the blood pump could be characterized by combined use of these two flow visualization techniques, and the significant role of circular flow in better washout was clarified., Lippincott-Raven Publ
ASAIO Journal, 1998, [Reviewed]

Development of a flow estimation and control system of an implantable centrifugal blood pump for, circulatory assist
Yoshinari Wakisaka; Yasuki Okuzono; Yoshiyuki Taenaka; Kenichi Chikanari; Seiko Endo; Toru Masuzawa; Hisateru Takano, A bypass flow rate estimation and control system (BECS) for an implantable centrifugal blood pump (ICBP) has been developed in our institute. The estimated flow rate (EF) of the ICBP was derived from the electric power consumption, the rotating speed of a motor, and the blood viscosity presumed by the hematocrit and body temperature. The error in the EF was 0.5 ± 0.4 L/min in vivo experiments for 40 days. The rotating speed of the motor was controlled automatically every 200 ms to bring the EF in accord with the desired flow rate (DF). The reactivity and accuracy of the BECS were investigated in vitro and in vivo experiments. The ICBP was operated by the BECS in a mock circuit in parallel with a pulsatile ventricular assist device (PVAD) to simulate left heart bypass. The reactivity was evaluated by changing the DF from 7 L/min to 5 L/min at an afterload of 160/97 mm Hg. To evaluate the accuracy of the BECS, the ICBP was driven under the aortic pressure of 110/85 mm Hg in the abdominal wall of an adult goat (70 kg). The DF was set at 5 L/min for 4 min for the goat in an awake condition. It took 13 s to change the flow rate in the in vitro experiment. The measured flow rate (MF) was maintained at 5.0 ± 0.2 L/min by the BECS in vivo. In conclusion, the BECS has moderate reactivity and accuracy.
Artificial Organs, 1998, [Reviewed]

Effect of gaps between impeller tip and casing wall upon hemolytic property of a centrifugal blood pump
MASUZAWA Toru; TSUKIYA Tomonori; ENDO Seiko; TATSUMI Eisuke; TAENAKA Yoshiyuki; YAMANE Takashi; NISHIDA Masahiro; ASZTALOS Balazs; MIYAZOE Yuki; ITO Kazuyuki; SAWAIRI Toshio; KONISHI Yoshiaki, The purpose of this study is to examine the relationship between the flow condition and hemolysis level by integrating hemolysis test, flow visualization and computational fluid dynamics(CFD)to establish design criteria for the good hemocompatible centrifugal pump. Axial and radial gaps between the impeller tip and casing wall of Nikkiso centrifugal blood pump were modified independently and flow condition and hemolytic property of these pumps were examined. Examined gaps were 1.5, 1.0, and 0.5 mm for axial gap and 3.0, 2.0, 1.0, and 0.5 mm for radial gap, respectively. The pumps with the axial gap of 0.5 mm and the radial gap of 0.5 mm showed higher hemolysis level than the other pumps showed. Maximum shear stress in the pump, estimated by CFD, were increased by decreasing the radial gap from 3.0 to 0.5 mm. Regional flow pattern change at the tongue region by decreasing radial gap was observed by flow visualization. Gaps between impeller tip and casing wall are dominant factors to determine hemolytic property of the centrifugal pump. Relationship between regional flow pattern and blood trauma should be investigated in the future., The Society of Life Support Engineering
ライフサポート, 1998

In vitro and in vivo heat dissipation of an electrohydraulic totally implantable artificial heart
S Endo; T Masuzawa; E Tatsumi; Y Taenaka; T Nakatani; T Ohno; Y Wakisaka; T Nishimura; Y Takewa; M Nakamura; K Takiura; YS Sohn; H Takano, The authors evaluated the heat transfer characteristics of an electrohydraulic totally implantable artificial heart (EH-TAH) developed at our institute. In three in vitro experiments, the heat dissipation of the EH-TAH was investigated. First, the EH-TAH was connected to a closed mock circuit filled with 1 L of saline, and driven at an input power of 20 W. The estimated heat conducted to the blood was similar to 10.3 W, which was almost half of the input power. Second, we simulated heat transfer with the circulation of a calf by using a heat exchanger. The amount of heat dissipating directly from the EH-TAH surface was calculated to be 10 W. Third, the temperature of the actuator examined with thermography was found to be almost uniform, and no prominent high temperature area was observed. In an in vivo study, the EH-TAH was implanted for 10 days in a calf weighing 62 kg. The input power was 18 +/- 2 W, the temperature of the actuator-tissue contacting surface was 39.5 +/- 0.8 degrees C, and that of the pump blood chamber was 39.8 +/- 0.4 degrees C. This slight temperature elevation was thought to be attributable to heat dissipation to the blood. On histologic study of the chest wall and the lung in contact with the actuator, vascularized connective tissue envelopes were observed, but unfavorable side effects, such as tissue necrosis, were not observed. These results suggest that the thermal effect of this system is acceptable at the input power used., LIPPINCOTT-RAVEN PUBL
ASAIO JOURNAL, Sep. 1997, [Reviewed]

Establishment of flow estimation for an implantable centrifugal blood pump
Yoshinari Wakisaka; Yasuki Okuzono; Yoshiyuki Taenaka; Kenichi Chikanari; Toru Masuzawa; Hisateru Takano, A less invasive and non thrombogenic flow estimation of an implantable centrifugal blood pump (ICBP) has been developed, which was derived from electric power consumption, the rotating speed of a motor, and blood viscosity presumed by hematocrit and body temperature. The power consumption and the rotating speed of the motor were measured by a wattmeter every 0.2 sec. Accuracy and stability of the estimated flow (EF) were investigated during in vitro and in vivo experiments. The EF was compared with a measured flow rate (MF) monitored by an electromagnetic flowmeter. During in vitro experiments, the EF and MF were measured at 79 operating points. The ICBP was driven in a closed mock loop filled with goat blood with hematocrit values of 21.5, 28, 34, and 42%. During in vivo experiments, the ICBP was implanted in the chest cavity of a goat and driven for 40 days with continuous estimation of the bypass flow rate. Blood was taken to determine hematocrit value several times a week. The temperature of the pleura away from the ICBP was measured every 15 min. A linear correlation between the EF and MF was observed, and the correlation coefficient between the EF and MF was 0.99 during in vitro examinations. An averaged error of the EF was 0.5 L/min, with the MF ranging from 2.3 to 8.1 L/min during in vivo experiments. In conclusion, flow estimation was established with good stability and accuracy in both in vitro and in vivo experiments., Lippincott-Raven Publ
ASAIO Journal, Sep. 1997, [Reviewed]

Hemodynamic and humoral conditions in stepwise reduction of pulmonary blood flow during venoarterial bypass in awake goats
Yoshiaki Takewa; Eisuke Tatsumi; Yoshiyuki Taenaka; Kazuhiro Eya; Takeshi Nakatani; Takashi Nishimura; Young-Sang Sohn; Toru Masuzawa; Yoshinari Wakisaka; Makoto Nakamura; Seiko Endo; Hisateru Takano; Soichiro Kitamura, The effects of reduced pulmonary arterial blood flow (PAF) during venoarterial bypass (VAB) on hemodynamic and humoral conditions were investigated in a series of experiments in a chronic animal model. A biventricular bypass system was installed in five adult goats weighing 49.8 ± 1.1 kg. Two weeks later, the extracorporeal circuitry was changed to VAB without anesthesia. The PAF was reduced stepwise from 100% to 50, 25, 10, and 0% of total systemic flow. The mean aortic pressure and systemic vascular resistance decreased from 110 ± 14 to 66 ± 3 mmHg and from 1,288 ± 77 to 740 ± 73 dyne · sec/cm5, respectively, in proportion to the decrease in PAF from 100 to 0%. The prostaglandin E2 concentration increased from 1.5 ± 0.6 to 8.8 ± 0.6 pg/ml following the decrease in PAF from 100 to 0%. The renin-angiotensin system increased in proportion to the decrease in PAF. In contrast, the epinephrine and norepinephrine concentrations (60 ± 10 and 227 ± 80 pg/ml, respectively, at 100% PAF) did not change appreciably even at 10% PAF, but were markedly elevated to 335 ± 117 and 2,088 ± 1,503 pg/ml at 0% PAF. The antidiuretic hormone level similarly changed. In conclusion, decrease in PAF during VAB exerts significant effects on hemodynamics in a proportional manner and on vasoactive humoral factors in a diverse manner., Lippincott-Raven Publ
ASAIO Journal, Sep. 1997, [Reviewed]

Morphologic changes of the aortic wall due to reduced systemic pulse pressure in prolonged non pulsatile left heart bypass
Takashi Nishimura; Eisuke Tatsumi; Shigeko Takaichi; Yoshiyuki Taenaka; Yoshinari Wakisaka; Takeshi Nakatani; Toru Masuzawa; Yoshiaki Takewa; Makoto Nakamura; Seiko Endo; Young-Sang Sohn; Hisateru Takano, The morphologic changes of the aortic wall due to reduced systemic pulse pressure in prolonged non pulsatile left heart bypass (LHB) were investigated. Sixteen adult goats were divided into three groups: the non pulsatile group in which non pulsatile LHB was conducted for 137 days on average, the pulsatile group in which pulsatile LHB was conducted for 79 days on average, and the control group used as the normal control. The average aortic pulse pressures were 12, 48, and 37 mmHg, respectively. At the end of the experiments, the descending aorta was excised and subjected to morphologic examination. The wall thickness of the aorta in the non pulsatile group (1.4 mm) was significantly thinner than that in the pulsatile group (2.2 mm) and the control group (2.0 mm), and the volume ratio of smooth muscle cells (SMC) in the non pulsatile group (37%) was lower than that in the pulsatile group (48%) and the control group (49%). In SMC classification, the proportion of SMC with low activity and low contractility in the non pulsatile group (57%) was high as compared with that in the pulsatile (2%) and control (5%) groups. These results strongly indicate that prolonged non pulsatile LHB causes substantial morphologic changes in the aorta., Lippincott-Raven Publ
ASAIO Journal, Sep. 1997, [Reviewed]

In vitro and in vivo evaluation of a left-right balancing capacity of an interatrial shunt in an electrohydraulic total artificial heart system
E Tatsumi; M Nakamura; T Masuzawa; Y Taenaka; YS Sohn; T Nishimura; M Nakata; T Nakatani; T Ohno; S Endo; K Takiura; Y Takewa; Y Kakuta; H Takano, The authors evaluated the basic performance of an interatrial shunt (IAS) made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in compliance with the amount of bronchial flow and the size of the IAS. The IAS of 4.4 mm diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in this IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5 mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4 +/- 1 mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. The authors conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system., LIPPINCOTT-RAVEN PUBL
ASAIO JOURNAL, Sep. 1997

Characteristics of mixed venous oxygen saturation and physical activity as parameters for artificial heart control
T Ohno; T Masuzawa; M Nakamura; E Tatsumi; Y Taenaka; T Nakatani; Y Wakisaka; T Nishimura; Y Takewa; H Takano; Y Fukui, Mixed venous oxygen saturation (SvO(2)) and physical activity (PhyAc) are practical candidates as parameters of total artificial heart (TAH) control because SvO(2) can be measured through a transparent blood pump housing with infrared rays and PhyAc can be calculated from signals of an accelerometer used for rate response pacemakers. Although the methods for measurement of the parameters have already been developed, characteristics of these parameters for TAH control, such as during exercise, are still unclear and were examined in this study. SvO(2), cardiac output (CO), and PhyAc were measured as parameters. Multi-stage treadmill exercise tests were performed. Difference values (DVs) from the value at the start of exercise showed better correlation than did absolute values. Correlation coefficients between DV in CO and DV in SvO(2) and between DV in CO and PhyAc were high at -0.82 and 0.72, while the time constants for the change of SvO(2) and CO to the PhyAc change were 26 and 32 sec. Although the correlation coefficient between the CO and SvO(2) was higher than that between CO and PhyAc, PhyAc responded more quickly to the speed change compared with the response of SvO(2) and CO. It was concluded that SvO(2) and PhyAc were useful parameters with different characteristics for TAH control during exercise., LIPPINCOTT-RAVEN PUBL
ASAIO JOURNAL, Sep. 1997

Noninvasive pump flow estimation of a centrifugal blood pump
Y Wakisaka; Y Okuzono; Y Taenaka; K Chikanari; T Masuzawa; T Nakatani; E Tatsumi; T Nishimura; Y Takewa; T Ohno; H Takano, A flow rate estimating method was investigated for a centrifugal blood pump developed in our institute. The estimated flow rate was determined by the power consumption, the rotating speed of the motor, and the hematocrit value. The power consumption and the rotating speed of the motor were measured with a wattmeter. The examinations were performed in a closed mock loop filled with goat blood with hematocrit values of 21.5%, 28%, 34%, and 42%. Measured values of blood viscosity were 2.47, 3.09, 3.71, and 5.07 mPa . s at a share rate of 37.5/s, respectively. A linear correlation between the power consumption and the pump flow rate was observed in all hematocrit values. But variations in hematocrit caused a difference in the flow rate up to 1.1 L/min at the same power consumption and rotating speed. Effects of blood viscosity on the flow estimation were corrected by the hematocrit value. The value of the coefficient of determination, RP between the estimated flow rate and the measured now rate was 0.988. These results may indicate that the now estimating method calculated by the power consumption of the motor, the rotating speed, and the hematocrit value is useful in the clinical situation., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, Jul. 1997, [Reviewed]

CHRONIC IN VIVO EVALUATION OF AN INTEGRATED ARTIFICIAL HEART-LUNG DEVICE AS A LONG-TERM CARDIOPULMONARY SUPPORT SYSTEM
TAKEWA Y.; TATSUMI E.; AKAGI H.; EYA K.; TAENAKA Y.; NAKATANI T.; MASUZAWA T.; WAKISAKA Y.; NISHIMURA T.; OHNO T.; TAKIURA K.; NAKAMURA M.; ENDO S.; SOHN Y-S.; TAKANO H.; YODA T; OKAMOTO T.; OHARA Y.; TANAKA S., We have developed an integrated artificial heart-lung device for long-term cardiopulmonary support. The device is composed of an artificial lung unit and two pusher-plate type artificial hearts which are connected to both sides of the artificial lung unit. The core size and the priming volume of the device are 11×14×17cm and 400ml, respectively. The hollow fibers of the artificial lung unit consist of a special polyolefin membrane which can prevent serum leakage. The entire blood-contacting surface of the artificial lung unit is treated with covalent heparin bonding. As a in vitro evaluation, the device exhibited a maximum output of 7.0L/min with a pressure gradient of around 10mmHg per 1L/min flow rate. In acute in vivo evaluation with two adult goats, the device satisfactorily replaced animals' circulation and respiration for 6 hours. Pumping output ranged from 5.5 to 6.0L/min, and PaO₂ and PaCO₂ were kept above 500mmHg and below 30mmHg, respectively. In chronic in vivo evaluation the device demonstrated a prominent thrombo-resistant property in non-heparin animal use trial. These results suggest that the integrated artificial heart-lung device has a potential to be used for long-term cardiopulmonary support with minimal anticoagulant therapy., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 15 Apr. 1997

Early changes in circulating blood volume and volume regulating humoral factors after implantation of an electrohydraulic total artificial heart
M. Nakamura; E. Tatsumi; T. Masuzawa; Y. Taenaka; T. Nakatani; Y. Sohn; S. Endo; T. Ohno; K. Takiura; T. Nishimura; Y. Takewa; Y. Wakisaka; H. Takano, The early changes in circulating blood volume (CBV) and volume regulating humoral factors after implantation of an electrohydraulic total artificial heart (EH-TAH) were investigated in a calf and compared with results in a sham operated control calf. CBV was measured by the dye dilution method using indocyanine green. CBV and humoral factors were periodically investigated. It is concluded that significant water retention occurs even at sufficient cardiac output early after EH-TAH implantation. The changes in humoral factors are suggested to arise secondary to the increased CBV or other unknown factors., Lippincott-Raven Publ
ASAIO Journal, 1997

人工肺(2)
小林 絋一; 武輪 能明; 巽 英介; 妙中 義之; 中谷 武嗣; 増澤 徹; 西村 隆; 中村 真人; 遠藤 誠子; 高野 久輝; 田中 操一; 猪狩 次雄; 星野 俊一; 岩谷 文夫; 引地 仁; 土本 勝也; 磯山 隆; 中村 真之; 田原 耕一郎; 桑名 克之; 森 康真; 川上 浩良; 長岡 昭二; 窪田 倭; 金森 敏幸; 新保 登志夫, JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, 1997

Long-term evaluation of a nonpulsatile mechanical circulatory support system
Yoshinari Wakisaka; Yoshiyuki Taenaka; Kenichi Chikanari; Takeshi Nakatani; Eisuke Tatsumi; Toru Masuzawa; Takashi Nishimura; Yoshiaki Takewa; Takashi Ohno; Hisateru Takano, Antithrombogenicity of a centrifugal pump (CP) developed in our institute is provided by a central balancing hole (BH) in the impeller. A current CP, the National Cardiovascular Center (NCVC)-2, was ameliorated to improve antithrombogenicity, whereby the BH diameter was widened to improve self washout flow velocity, and an edge of the thrust bearing was rounded off to minimize flow separation. Effects of these modifications were assessed in a long-term in vivo experiment. The antithrombogenicity, hemolytic property, and mechanical durability of the NCVC-2 were investigated in 3 goats. The NCVC-2 was installed paracorporeally between the left atrium and the aorta and driven as long as possible at rotating speeds of about 2,800 rpm. The NCVC-2 ran for 50, 200, and 367+ days. The mean bypass flow rates were 6,8, 5.0, and 5.3 L/min, respectively. Creatinine, blood urea nitrogen (BUN), glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) did not increase until one week before termination. Plasma free hemoglobin was kept to a level less than 15 mg/dl, except for the last week of the second case. These results indicate that the NCVC-2 has excellent antithrombogenicity, an acceptable hemolytic property and the necessary durability for prolonged use., Blackwell Publishing Inc.
Artificial Organs, 1997, [Reviewed]

Impact of systemic depulsation on tissue perfusion and sympathetic nerve activity
Koichi Toda; Eisuke Tatsumi; Yoshiyuki Taenaka; Toru Masuzawa; Hisateru Takano, Background. We postulated that pathophysiologic processes under nonpulsatile circulation are related to the behavior of the sympathetic nerve activity that regulates tissue perfusion. Methods. Pulsatile and nonpulsatile pumps were installed in parallel in the left heart bypass circuit of anesthetized goats (n = 9) so that pulsatile circulation could be converted to nonpulsatile circulation instantly. At 5 minutes before and after systemic depulsation, we measured hemodynamic indices, renal nerve activity, and regional blood flow of the brain, heart, and renal cortex. Results. Renal nerve activity was significantly elevated after systemic depulsation (15.6 ± 9.3 versus 19.4 ± 9.8 μV), when mean aortic pressure remained almost constant. The renal cortical flow was significantly reduced after depulsation (3.61 ± 1.23 versus 2.93 ± 1.19 mL · min-1 · g-1), whereas no significant difference was found in the regional blood flow of the brain or the heart. Conclusions. The significant reduction of renal cortical blood flow after systemic depulsation is associated with a significant increase in renal nerve activity. Our results suggest that increased renal nerve activity plays an important role in the reduction of renal function after systemic depulsation.
Annals of Thoracic Surgery, Dec. 1996, [Reviewed]

Development of a precise controller for an electrohydraulic total artificial heart - Improvement of the motor's dynamic response
JM Ahn; T Masuzawa; Y Taenaka; E Tatsumi; T Ohno; WW Choi; K Toda; K Miyazaki; Y Baba; T Nakatani; H Takano; BG Min, In an electrohydraulic total artificial heart developed at the National Cardiovascular Center (Osaka, Japan), two blood pumps are pushed alternatively by means of the bidirectional motion of a brushless DC motor for pump systole and diastole. Improvement in the dynamic response of the motor is very important to obtain better pump performance; this was accomplished by using power electronic simulation. For the motor to have the desired dynamic response, it must be commutated properly and the damping ratio (zeta), which represents transient characteristics of the motor, must lie between 0.4 and 0.8. Consequently, all satisfactory specifications with respect to power consumption must be obtained. Based on the simulated results, the design criteria were determined and the precise controller designed to reduce torque ripple and motor vibration, and determine motor stop time at every direction change. In in vitro tests, evaluation of the controller and dynamic response of the motor was justified in terms of zeta, power consumption, and motor stop time. The results indicated that the power consumption of the controller and the input power of the motor were decreased by 1.2 and 2.5 W at zeta = 0.6, respectively, compared to the previous system. An acceptable dynamic response of the motor, necessary for the reduction of torque ripple and motor vibration, was obtained between zeta = 0.5 and zeta = 0.7, with an increase in system efficiency from 10% to 12%. The motor stop time required for stable motor reoperation was determined to be over 10 msec, for a savings in power consumption of approximately 1.5 W. Therefore, the improved dynamic response of the motor can contribute to the stability and reliability of the pump., LIPPINCOTT-RAVEN PUBL
ASAIO JOURNAL, Sep. 1996

Tandem operation of a turbo blood pump (BP-80-type centrifugal pump) to reduce hemolysis
Wakisaka Y; Taenaka Y; Nakatani T; Anai H; Araki K; Nishimura T; Tatsumi E; Masuzawa T; Baba Y; Toda K; Eya K; Miyazaki K; Takewa Y; Takano H, When operating turbo blood pumps in tandem, the strength of shear stress is reduced, but the exposure duration of the stress is increased. The purpose of this experiment was to compare the degree of contribution of these two factors on hemolysis as well as to evaluate the effectiveness of the tandem operation of turbo blood pumps. Tandem operation of two Bio-pumps (BP-80; Medtronics Bio-medicus, Inc., Eden Prairie, Minnesota, U.S.A,) were compared with single operation of a BP-80 in in vitro hemolysis tests in three different driving conditions, that is, pumping heads of 200, 350, and 500 mm Hg under a pump flow rate of 5 L/min. The Alien's hemolytic indexes of the tandem operation at pumping heads of 200, 350, and 500 mm Kg were 0.014, 0.020, and 0.080 mg/dl, respectively. The hemolytic indexes of the single operation at pumping heads of 200, 350, and 500 mm Hg were 0.014, 0.056, and 0.12 mg/dl, respectively. These results indicate that tandem operation is a useful method of reducing hemolysis with the BP-80 under high pumping heads and that the effect on hemolysis of exposure to higher shear stresses may be more serious than that of longer durations of exposure to shear stress in, Artificial Organs
Artificial Organs, 07 Aug. 1996

Sympathetic nerve activities in pulsatile and nonpulsatile systemic circulation in anesthetized goats
Koichi Toda; Eisuke Tatsumi; Yoshiyuki Taenaka; Toru Masuzawa; Hisateru Takano, To investigate the effects of pulsatile and nonpulsatile systemic circulation on the sympathetic nerve activity, using a left heart bypass technique, we converted systemic circulation between the pulsatile and the nonpulsatile mode in anesthetized goats and analyzed differences in periodicity and quantity of renal nerve activity (RNA). After pulsatile systemic circulation was converted to the nonpulsatile mode, the mean RNA was significantly increased from 10.7 ± 3.6 to 13.1 ± 3.4 μV and periodic discharges of RNA, which corresponded to pulse-related rhythm during pulsatile circulation, became obscure, whereas an 8-12 cycle/s rhythm, which was distinguished and accounted for 30 ± 9% of total intervals during pulsatile circulation, became dominant (48 ± 11%). These results clarified a significant increase in mean RNA after depulsation of the systemic circulation and indicated that the cardiac related rhythm in RNA could be produced by periodic inputs from arterial baroceptors alone, whereas the 8- 12 cycle/s rhythm that was present regardless of the type of circulation was the fundamental rhythm originating from the vasomotor center.
American Journal of Physiology - Heart and Circulatory Physiology, Jul. 1996, [Reviewed]

Development of a centrifugal pump with improved antithrombogenicity and hemolytic property for chronic circulatory support
Y Taenaka; Y Wakisaka; T Masuzawa; E Tatsumi; K Toda; K Miyazaki; K Eya; Y Baba; T Nakatani; T Ohno; T Nishimura; H Takano, A centrifugal pump with a unique structure has been developed for chronic support. The pump is driven by a magnetic coupling and has no rotating shaft, no seal around the rotating part, and a balancing hole at the center of the impeller and the thrust bearing. The pump was improved in stepwise fashion to realize good antithrombogenicity and low hemolysis. The first pump, the National Cardiovascular Center (NCVC)-0, had an impeller with 4 rectangular and curved vanes; 6 triangularly shaped curved vanes were employed in the second model, the NCVC-1, to reduce trauma to the blood. In the third design, the NCVC-2, the central hole was enlarged, and the thrust bearing shoulder was rounded so that blood washing was enhanced around the impeller; stream lines also were smoothed for improved antithrombogenicity. The hemolytic property of the device was evaluated in vitro with heparinized fresh goat blood; hemolysis indexes of the NCVC-0, -1, and -2 were 0.05, 0.01, and 0.006 g per 100 L, respectively. Antithrombogenicity of the pumps was examined in animal experiments as a left heart bypass device in goats weighing 52-75 kg. Six NCVC-0 pumps were driven for 14 to 33 (22.0 +/- 7.6) days in goats receiving the antiplatelet drug cilostazol orally. Four NCVC-1 pumps ran for 1 to 80 (28.5 +/- 30.6) days with the same drug regimen in 2 cases and with no anticoagulation therapy in 2 cases. After 3 preliminary 1-week tests of NCVC-2 pumps in animals, the pump was installed in 3 goats; 2 pumps were still running on the 182nd and 58th pumping day. Intracorporeal implantation also was attempted successfully. The results indicate that this pump has promising features for chronic support although longer term and additional evaluations are necessary., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, Jun. 1996

DEVELOPMENT AND EVALUATION OF A HEPARIN-BONDED MENMBRANE OXYGENATOR FOR LONG-TERM RESPIRATORY SUPPORT
EYA K; TATSUMI E; TAENAKA Y; TAKEWA Y; TODA K; WAKISAKA Y; NAKATANI T; BABA Y; MASUZAWA T; MIYAZAKI K; NISHIMURA T; OHNO T; TAKANO H; MIMURA R; TANAKA S; HARADA I, We developed a membrane oxygenator (MO) for long-term respiratory support. The MO is made with polyolefin hollow fiber membrane where micropores are blind-ended to prevent serum leakage. And the blood contacting surface is treated with newly developed covalently heparin-bonding technique to provide good antithrombogenicity. In vivo evaluation of the MO was performed with 4 adult goats for a week. Throughout the experiment, the gas transfer rates were well maintained and the levels of coagulation parameters remained relatively constant and within physiologic ranges. After the device was removed and rinsed with saline, no apparent macroscopic thrombus formation was found in two cases. Scanning electron microscopic examination, however, revealed several fibrin clots on the surfaces in these cases. These results suggest that the antithrombotic properties should be bettered for application of this MO to such a long-term respiratory support as a bridge to lung or heart-lung transplantation., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 15 Apr. 1996

Influence of ventricular fibrillation on sympathetic nerve activity under biventricular bypass circulation
K Toda; E Tatsumi; Y Taenaka; T Masuzawa; K Miyazaki; T Nakatani; Y Baba; K Eya; Y Wakisaka; H Takano, Autonomic nerves play an important role in circulatory control. The characteristics of sympathetic nerve activity (SNA) during artificial circulation, however, are not well understood. In this study, we examined the influence of natural heart beating on the renal SNA (RSNA) using pulsatile 100% biventricular assistance and electrically induced ventricular fibrillation in anesthetized goats, whose heart rate and size are similar to the human heart's. Following induction of the ventricular fibrillation, the pulse-synchronous discharges in the RSNA did not change their periodicity and quantity significantly, It was concluded that the beating of the heart had little influence on the RSNA and was presumably not essential for maintaining nervous control of circulation as long as the circulation was maintained by an artificial heart., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, Feb. 1996, [Reviewed]

Charging and discharging control of rechargeable backup-battery for a totally implantable artificial heart.:-Characteristics of lithium ion rechargeable battery
YASUE H; SHIBA K; KOSHIJI K; SHU E; UTSUNOMIYA T; OHNO T; MASUZAWA T; TATSUMI E; TAENAKA Y; TAKANO H, We study charge and discharge characteristics of a lithium ion rechargeable backup-battery under a condition of same temperature as inside of body for a totally implantable artificial heart. The seven cells of lithium ion battery in series connection were charged on condition of constant voltage of 29.4V (maximum charging current of 1000mA), and they required 84 minutes to be fully charged. We connected the 7-cell lithium ion battery with a mock load of 25Ω, which electrically simulates a typical TAH actuator, and measured dischargeable time of the battery for the mock load. It was dischargeable for 60 minutes, and the terminal voltage varied from 28.9V to 18.9V in this process. The dischargeable time was compared with 20-cell NiCd rechargeable battery with same voltage and same volume as the 7-cell lithium ion battery. It was found that the lithium ion was dischargeable twice as long as the NiCd. Using the terminal voltage of the lithium ion varying in discharging process, we investigated to monitor residual energy of the lithium ion battery. As a result, the residual energy of the battery could be monitored in either of continuously and intermittently discharging using the terminal voltage. And the surface temperature rise of the lithium ion battery was 2°C in case of charge and 8°C in case of discharging. It was found that the lithium ion battery had higher energy density and smaller temperature rise compared with NiCd battery., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 1996

Influence of non pulsatile systemic circulation on tissue blood flow and oxygen metabolism
Eisuke Tatsumi; Koji Miyazaki; Koichi Toda; Yoshiyuki Taenaka; Takeshi Nakatani; Yuzo Baba; Toru Masuzawa; Yoshinari Wakisaka; Kazuhiro Eya; Takashi Nishimura; Yoshiaki Takewa; Takashi Ohno; Hisateru Takano, Influence of non pulsatile systemic circulation on oxygen metabolism was examined regarding tissue perfusion in 12 adult goats weighing from 46 to 55 kg. Under general anesthesia, a flow character, changeable total left heart bypass circuit consisting of pulsatile and non pulsatile pumps was installed through a left thoracotomy. Systemic flow was converted from pulsatile to non pulsatile in 7 of 12 animals, and in the reverse order in the other 5, by changing the driving pump. Esophageal mucosal blood flow was determined by a colored microsphere method that estimated tissue blood flow at the pre capillary level. Esophageal intramucosal pH was evaluated with a silicone balloon tonometer catheter surgically placed in the submucosal space. Hemodynamic and arterial blood gas parameters were unchanged at flow mode conversion. Although oxygen delivery was comparable between pulsatile and non pulsatile circulation, oxygen extraction ratio was lower and venous oxygen saturation was higher in non pulsatile than pulsatile circulation. Although statistically not significant, serum lactate level tended to be higher with non pulsatile circulation. No difference was observed in esophageal mucosal blood flow between pulsatile and non pulsatile circulation, whereas intramucosal pH, which strongly correlated with arterial pH regardless of the flow mode, was significantly lower under non pulsatile than pulsatile conditions. In conclusion, systemic oxygen uptake is less efficient in non pulsatile than pulsatile circulation in the setting of an acute experiment using animals, which may be accounted for by the disparity between the pre capillary blood flow and actual tissue oxygen metabolism., Lippincott Williams and Wilkins
ASAIO Journal, 1996

Altered oxygen metabolic conditions associated with increased norepinephrine levels in a nonpulsatile systemic circulation
Eisuke Tatsumi; Koji Miyazaki; Koichi Toda; Yoshiyuki Taenaka; Takeshi Nakatani; Yuzo Baba; Toru Masuzawa; Kazuhiro Eya; Yoshinari Wakisaka; Takashi Nishimura; Yoshiaki Takewa; Takashi Ohno; Hisateru Takano, Change in oxygen metabolic conditions accompanying the conversion of systemic flow from pulsatile to nonpulsatile (from P-mode to N-mode) was investigated in association with blood norepinephrine levels. Total left heart bypass was instituted through a left thoracotomy under general anesthesia in 10 adult goats. Pulsatile and nonpulsatile pumps were incorporated in the circuit in parallel, and the flow character was rapidly converted from the P-mode to the N-mode. Norepinephrine levels increased significantly after the conversion, from 222 ± 54 pg/ml to 285 ± 65 pg/ml. While oxygen delivery (DO2) was kept constant, the oxygen extraction ratio significantly decreased, from 21 ± 3% to 16 ± 3%, and venous oxygen saturation (SvO2) significantly increased, from 77 ± 6% to 84 ± 6% after depulsation. The serum lactate level was significantly higher in the N-mode than the P-mode (P-mode: 35 ± 2 mg/dl, N-mode: 45 ± 5 mg/dl). Strong positive and negative correlations of norepinephrine levels were observed with oxygen extraction ratio and SvO2, respectively, whereas norepinephrine levels did not correlate with DO2. Regression lines in these correlations unveiled higher oxygen uptake in the P-mode than the N-mode at the same norepinephrine level. These results indicate that, in the setting of an acute animal experiment, oxygen uptake is less efficient with the absence of pulsatility, and the higher norepinephrine concentration functioned to tune the oxygen metabolism in the initial stage of nonpulsatile systemic circulation., Lippincott Williams and Wilkins
ASAIO Journal, 1996

Development of an integrated artificial heart-lung device for long-term cardiopulmonary support
Eisuke Tatsumi; Yoshiaki Takewa; Haruhiko Akagi; Yoshiyuki Taenaka; Kazuhiro Eya; Takeshi Nakatani; Yuzo Baba; Toru Masuzawa; Yoshinari Wakisaka; Koichi Toda; Koji Miyazaki; Takashi Nishimura; Takashi Ohno; Hisateru Takano, An integrated artificial heart-lung device has been developed as a long- term cardiopulmonary support system. The device is composed of gas exchange and pumping units. The gas exchange unit consists of a special hollow fiber membrane that can prevent serum leakage. The entire blood contacting surface of the gas exchange unit is treated with covalent heparin bonding. The pumping unit consists of two pusher-plate artificial hearts joined to each end of the artificial lung unit. The core size and priming volume of the device are 11 x 14 x 17 cm and 400 ml, respectively. In in vitro evaluation, the device exhibited a maximum output of 7.0 L/min, with a pressure gradient of 10 mmHg per 1 L/min flow rate. In acute in vivo evaluation with adult goats, the device satisfactorily replaced the animals' circulation and respiration for 6 hr. Pumping output ranged from 5.5 to 6.0 L/min, whereas PaO2 and PaCO2 were kept above 500 mmHg and below 30 mmHg, respectively. The device demonstrated prominent thrombus resistant properties in nonheparin animal use trials. These results indicate that the integrated artificial heart-lung device has a potential to be a long-term cardiopulmonary support system that can be used with minimal anticoagulant therapy., Lippincott Williams and Wilkins
ASAIO Journal, 1996

Development of a membrane oxygenator for long-term respiratory support and its experimental evaluation in prolonged ECMO
Kazuhiro Eya; Eisuke Tatsumi; Yoshiyuki Taenaka; Yoshiaki Takewa; Yoshinari Wakisaka; Koichi Toda; Takeshi Nakatani; Toru Masuzawa; Yuzo Baba; Koji Miyazaki; Takashi Nishimura; Takashi Ohno; Jae Mok Ahn; Hisateru Takano; Rishichi Mimura; Soichi Tanaka; Toru Wada, The authors developed a new membrane oxygenator (MO) for long-term respiratory support and evaluated its performance in animal experiments for as long as 336 hr. The MO, with a membrane area of 1.2 m2 and priming volume of 140 ml, is compact and designed to be interposed in a ventricular assist system (VAS) conduit. It is made with a novel hollow fiber membrane, in which micropores are blind-ended so that serum leakage can be prevented during prolonged use. The blood contacting surface of the MO is heparinized with a newly developed covalent bonding technique that ensures good thrombus resistance. In vivo evaluation with five adult goats was performed by installing the MO into a venoarterial or venovenous bypass circuit. No systemic anticoagulant therapy was used, except for a heparin-added fluid infusion to keep the pressure monitoring lines open (2-3 U/kg/hr). Throughout the experiments, no plasma leakage was observed, and gas transfer rates were maintained in a satisfactory range. Platelet counts did not decrease to less than 60% of levels before bypass, and hemolysis was negligible. The levels of coagulation parameters including fibrinogen, fibrin degradation products (FDP), antithrombin III (AT III), anti-plasmin, prothrombin time (PT) and activated partial thromboplastic time (APTT) remained within physiologic ranges and relatively constant. At the end of the evaluation, no thrombus formation was noted in three of five MOs. These results suggest that this MO is a promising device for long-term respiratory support., Lippincott Williams and Wilkins
ASAIO Journal, 1996

Evaluation of a two stage axial flow pump on hemolysis
Wakisaka Y; Anai H; Nakatani T; Araki K; Taenaka Y; Tatsumi E; Masuzawa T; Baba Y; Toda K; Eya K; Takano H, To reduce hemolysis in an axial flow pump (AP), a basic study of a two stage AP (2S) was performed. The 2S was evaluated in two kinds of in vitro hemolysis tests for four hours. In this first test, the 2S was compared with two kinds of single stage (APs (ISs). Each pump was designed to be operated at a flow rate of 5 l/min and a pressure head of 100 mmHg. The 2S was series operation of two single stage APs designed at a flow rate of 5 λ/min and a pressure head of 50 mmHg. One of the ISs has the same specific speed (Ns) of the 2S and the other IS has the same impeller of the single stage of the 2S. In the second test, hemolysis in each stage of the 2S was evaluated. The basic structure of all single stage APs were same. Allen's hemolytic index (III) of the 2S, that was regarded as an aggregate III of both stage AP, was less than those of the ISs. These data suggests that the 2S was useful to reduce hemolysis in an AP., Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1996

Set-up, improvement, and evaluation of an electrohydraulic total artificial heart with a separately placed energy converter. (jointly authored)
T Masuzawa; Y Taenaka; E Tatsumi; JM Ahn; T Ohno; K Toda; K Miyazaki; Y Wakisaka; K Eya; Y Baba; T Nakatani; H Takano; C Uyama; K Koshiji; Y Fukui; K Takahashi; K Tsuchimoto; K Tsukahara, The authors have been developing an electrohydraulic total artificial heart (TAH) system with a separately placed electrohydraulic energy converter to minimize anatomic constraints in the pericardial space. Improvements to the system and current status of the development are reported. The energy converter was miniaturized to improve implantability, and its thickness was reduced to 54 mm. System efficiency was increased by suppressing rush current at the time of motor reversal. Maximum cardiac output of the TAH system was 9 L/min, and maximum system efficiency increased to 10%. The blood pump system was implanted easily in the body of a 57 kg calf, and no significant temperature rise on the energy converter surface was observed. As the next step, main components were integrated into a total system. The transcutaneous energy transfer system could supply power to the TAH without a decline in pump performance, and the internal battery could support the system at 6.5 L/min of cardiac output for 1 hour without a decrease in cardiac output. The authors consider the TAH system with a separately placed energy converter the most promising approach to development of a TAH for smaller sized patients., LIPPINCOTT-RAVEN PUBL
ASAIO Journal, 1996

Improvement of a totally implantable electrohydraulic artificial heart system to the evaluation stage by chronic animal experiments
増澤徹
人工臓器, 1996

HEMOLYSIS AND HEAT-GENERATION IN 6 DIFFERENT TYPES OF CENTRIFUGAL BLOOD PUMPS
K ARAKI; Y TAENAKA; T MASUZAWA; E TATSUMI; Y WAKISAKA; M WATARI; T NAKATANI; H AKAGI; Y BABA; H ANAI; YH PARK; K EYA; K TODA; H TAKANO, What the most causative factor affecting hemolysis is still controversial. To resolve this problem, we investigated the relationship between hemolysis and heat generation in six types of centrifugal blood pumps (Bio-Pump, Delphin, Capiox, Nikkiso, Isoflow, and Toyobo). The analyzed parameters were index of hemolysis in fresh goat blood, pumping performance, and heat generation in a thermally isolated mock circuit. These parameters were analyzed at a flow rate of 5 L/min by changing the pressure head (100 mm Hg and 500 mm Hg). At 500 mm Hg of pressure head, the Bio-Pump needed the highest rotation number and showed the highest hemolytic rate and heat generation. The index of hemolysis is well correlated to heat generation (r(2) = 0.721). Heat may originate from the motor by conduction, hydraulic energy loss, and mechanical friction between the shaft and seal. We strongly suspect that hemolysis was caused by a factor such as mechanical friction which generates heat locally., BLACKWELL SCIENCE PUBL INC CAMBRIDGE
ARTIFICIAL ORGANS, Sep. 1995

Development and in vivo evaluation of an implantable left ventricular assist system with an impedance based monitoring and control system
T NAKATANI; H ANAI; K EYA; Y WAKISAKA; K TODA; Y TAENAKA; E TATSUMI; T MASUZAWA; Y BABA; H TAKANO, We have developed an implantable pneumatically driven diaphragm left ventricular assist system (LVAS) for small adults, and an electric impedance based monitoring and control system (Z system). In this Z system, measurement of electric impedance of the blood chamber is performed by charging an alternating current with a constant amplitude between two metal connectors without compromising antithrombogenicity. Automatic calibration was performed periodically by measuring trough values of impedance in the blood chamber for several beats while the blood pump was in a full-fill state under preset driving conditions. For precise control of the fill-to-empty (F/E) drive, an automatic trigger level adjustment method was developed. This method is an automatic searching algorithm that identifies the volume change of the last ejection or filling by the Z system and settles the next trigger level to maintain a definite stroke volume. In chronic in vivo evaluation, this LVAS was used in 13 adult goats. The pump was installed between the LV apex and the descending aorta and was placed in the abdominal walt. Pump output ranged from 2.5 to 5.8 L/min, and the Z system provided good monitoring. The F/E drive was achieved satisfactorily by this Z system. The physical condition of the goats was excellent for as long as 19 weeks. Hematologic, hepatic, and renal functions were within the normal range, and no prominent thromboembolic symptoms were observed. A new mobile control drive unit with this Z system is being developed. We conclude that this LVAS with the Z system is promising for long-term use in a clinical setting., LIPPINCOTT-RAVEN PUBL
ASAIO JOURNAL, Jul. 1995, [Reviewed]

Heat generation and hemolysis at the shaft seal in centrifugal blood pumps
Araki K; Taenaka Y; Wakisaka Y; Masuzawa T; Tatsumi E; Nakatani T; Baba Y; Eya K; Toda K; Takano H; Koga Y; Yagura A, The heat and hemolysis around a shaft seal were investigated. Materials were original pumps (Nikkiso HMS-15:N-original, and 3M Delphin:D-original), vane-removed pumps (Nvane(-), Dvane(-)), and a small chamber with a shaft coiled by nichrome wire (mock pump). The original pumps were driven at 500 mmHg and 5 L/min, and vane-removed pumps were driven at the same rotation number. An electrical power of 0, 0.5, 2, and 10 W was supplied to the mock pumps. In vitro hemolytic testing showed that hemolytic indices were 0.027 g/100 L in N-original, 0.013 in Nvane(-), 0.061 in D-original, and 0.012 in Dvane(-). Measurement of heat with a thermally insulated water chamber showed total heat within the pump of 8.62 and 10.85 W, and heat at the shaft seal of 0.87 and 0.62 W in the Nikkiso and Delphin pumps, respectively. Hemolysis and heat generation of mock pumps remained low. The results indicate that the heat generated around the shaft seal was minimal. Hemolysis at the shaft-seal was considerable but not major. Local heat did not affect hemolysis. It was concluded that the shaft-seal affected hemolysis, not by local heat but friction itself., ASAIO Journal
ASAIO Journal, 01 Jan. 1995

Improvement in antithrombogenicity in a centrifugal pump with self wash-out structure for long-term use
Wakisaka Y; Taenaka Y; Tatsumi E; Araki K; Masuzawa T; Nakatani T; Baba Y; Anai H; Eya K; Toda K; Takano H, Antithrombogenicity in the initial (NCVC-1) centrifugal pump (CP) developed at our institute is provided by a central balancing hole in an impeller that promotes self wash-out blood flow (Sf) around the impeller. The current CP (NCVC-2) was ameliorated to obtain better antithrombogenicity, where the balancing hole diameter was widened to improve Sf velocity (Vsf), and the edge of a thrust bearing (TB) was rounded to minimize flow separation. Effects of the modifications were assessed in in vitro and in vivo studies. The Vsf of the NCVC-1 and the NCVC-2 evaluated by Doppler velocimeter were 12.8 and 22.1 cm/sec, respectively. Flow around the TB visualized by a light cutting method confirmed less flow stagnation in the NCVC-2. In vivo antithrombogenicity of the CPs was investigated in three goats. A pulsatile VAD (P-VAD) was installed paracorporeally between the left atrium and the aorta. After 3 weeks, the P-VAD was exchanged for the NCVC-2 and the NCVC-1 in sequence. Each CP was driven for 1 week and disassembled. No anticoagulation was used, except for heparin injection at pump exchange. Thrombus at the TB was found in the two NCVC-1s, and two little thrombi were on the impeller o, ASAIO Journal
ASAIO Journal, 01 Jan. 1995

Experimental evaluation of intravenous axial flow pump for right heart assist
Nakatani T; Anar H; Wakisaka Y; Araki K; Taenaka Y; Tatsumi E; Akagi H; Masuzawa T; Baba Y; Eya K; Toda K; Tominaga M; Choi W; Kitoh Y; Takano H, We have developed intravenous axial flow pump for right heart assist. In this study, experimental evaluation of this system was performed. The pump was positioned in the right heart through a 14 mm, low porosity graft anastomosed to the infrarenal inferior vena cava. The pump showed good performance in right heart assistance under induced pulmonary stenosis or induced biventricular failure. Chronic animal experiments were performed using adult goats. There was no difficulties in pump insertion. Level of plasma hemoglobin was acceptable. There was not prominent damages in heart tissues. In conclusion, this pump system is practicable for temporary right heart assist., Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1995

Development of an intravenous axial flow pump for temporary right heart assist
Nakatani T; Anai H; Wakisaka Y; Taenaka Y; Tatsumi E; Masuzawa T; Baba Y; Eya K; Toda K; Araki K; Takano H, In clinical settings, quick application systems with easy access for circulatory support are desired. For left heart assist, an intraarterial axial flow pump (Hemopump) has been developed and applied to clinical cases. However, no simple way has been proposed for right heart assist. We have developed an intravenous axial flow pump for temporary right heart assist and have reported its hemodynamic effect. In this study, in vivo evaluation of this system was performed. The pump system consists of an outflow cannula, an impeller that was newly developed for intravenous use, and a driving system for the Hemopump. A prototype pump demonstrated 3.2 L/min of maximal flow at a pressure differential against 40 mmHg at a pump speed of 28,000 rpm in mock circulation. Application to goats is as follows. A 14 mm low porosity graft was anastomosed to the infrarenal inferior vena cava (IVC). The pump system was inserted into the IVC through the graft and advanced to the right heart using balloon catheter guidance under fluoroscopy, and the tip of the cannula of the pump was positioned at the main pulmonary artery. In acute experiments, this system provided effective right heart assist under induc, ASAIO Journal
ASAIO Journal, 01 Jan. 1995

Approach to decrease hemolysis caused by axial blood flow pump
Anai H; Araki K; Nakatani T; Wakisaka Y; Taenaka Y; Tatsumi E; Akagi H; Masuzawa T; Baba Y; Eya K; Toda K; Takano H, To decrease hemolysis caused by an axial flow blood pump, we studied whether specific speed at the design point should be kept within the existing engineering standard range or whether pump speed should be reduced to a minimum. Four pumps were designed at a flow of 5 L/min, a head of 100 mmHg and speeds of 14000-26000 rpm. Specific speed of each pump was calculated as 758-1407 (m, m 3 /min, rpm). Hemolytic tests were performed with flesh goat blood in a mock circuit. The lowest level of hemolysis is observed in the pump with the minimum specific speed (758) that is out of the existing engineering standard range. We also studied the influence of change in design of guide vanes on hemolysis. Four guide vanes that had different length and number of vanes were devised for same impellers. In the result of hemolysis test, difference in hemolytic index was not clearly observed among the pumps that had different guide vanes., Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1995

Heat generation and hemolysis in centrifugal blood pumps
Araki K; Taenaka Y; Masuzawa T; Wakisaka Y; Nakatani T; Akagi H; Baba Y; Anai H; Eya K; Toda K; Takano H, We investigated the effect of heat and friction around a shaft-sealing on hemolysis in centrifugal blood pumps. The materials were original pumps (Nikkiso HMS-15 and 3M Delphin), vane-removed pumps and a small chamber with a shaft coiled by a nichrome wire (mock pump) to investigate the effect of local heat on hemolysis. In-vitro hemolytic examination was carried out using heparinized fresh blood of a goat. The original pumps were driven at the flow rate of 5 L/min and pressure head of 500 mmHg. The vane-removed pumps were driven at the same rotation number and the flow of 5 L/min was maintained by Bio-pumps (1000 rpm). Electric power of 0, 0.5, 2 and 10 Watts was supplied to the mock pump and the flow was maintained in the same way. We also measured generated heat of the original pumps and vane-removed pumps with a thermally-insulated water chamber. The results indicated that the heat generated around the shaft-sealing was minimal. The hemolysis of the shaft- sealing was, however, considerable but not principal. The local heat less than 10 Watts did not affect hemolysis. We concluded that a shaft-sealing affects hemolysis by not local heat but the friction, and the main causative, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1995

Development of an electrohydraulic total artificial heart at the National Cardiovascular Center, Osaka, Japan. (jointly authored)
T MASUZAWA; Y TAENAKA; E TATSUMI; WW CHOI; K TODA; T OHNO; Y BABA; T NAKATANI; H TAKANO; C UYAMA; K KOSHIJI; Y FUKUI; K TAKAHASHI; T OHMI, The authors have been developing an electrohydraulic total artificial heart with a basic concept placing the blood pumps and an electrohydraulic energy converter separately, in the thorax and the abdominal region, respectively, to minimize anatomic constraints. Major problems of the system were a high energy consumption of 56 W at 6 L/min output and an insufficient maximum output of 6.7 L/min. The energy converter was redesigned to overcome these problems. A three phase, 4 pole brushless DC motor, which has maximum efficiency of 79% at a motor rotation of 2500 rpm with a load of 0.1 Nm, was developed for the new energy converter. Flow-channel design of the regenerative oil pump was optimized, which resulted in increasing the maximum flow rate at one directional motor rotation from 18 to 29 L/min. In vitro performance of the electrohydraulic total artificial heart was evaluated in a mock circulation with physiologic pressure conditions. Maximum output was increased to 10.7 L/min at a pump rate of 120 bpm and energy consumption of the motor at 6 L/min output was reduced to 18 W. Based upon these favorable results, the system is now being assembled for chronic animal implantation., LIPPINCOTT-RAVEN PUBL
ASAIO Journal, 1995

Development of totally implantable artificial heart-Electrohydraulic total artificial heart with a regenerative pump energy converter
MASUZAWA Toru; TAENAKA Yoshiyuki; TATSUMI Eisuke; NAKATANI Takeshi; AKAGI Haruhiko; TAKANO Hisateru; TAKASHI Koshiji; OHNO Takashi; FUKUI Yasuhiro; TAKAHASHI Katumi; SASAGAWA Hiroshi; TUKAHARA Kinji; TUTIMOTO Katsuya; OHMI Takeharu, We have been developing an electrohydraulic total artificial heart (EH) with a motor integrated regenerative pump as an energy converter, The motor and the regenerative pump was improved to move a chronic animal implantation. Three phases and four poles brushless DC motor, which has maximum efficiency of 79% at a motor rotation of 2500rpm with a load of 1kg/cm, was developed for the new actuator. Design of flow channel of the regenerative oil pump was optimized, which resulted in increasing maximum flow rate at one directional motor rotation from 18 to 28L/min. In vitro performance of the EH was evaluated in a mock circulation with 100mmHg of afterload on the left side, 20mmHg on the right side, and 10mmHg of preload on both sides. Maximum output was 10.7L/min at a pump rate of 120bpm Double diaphragm type blood pump (DDP) was also developed to compensate the balance between left and right pump output. Preload sensitive ability of the DDP was evaluated in in vitro experiment. We will turn upon a chronic animal experimental stage with the EH in next few months., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, 1995

The animal experiments of total artificial heart at the national cardiovascular center in japan　　　　　　　　　　　　　　　
HY Park; Tatsumi E; Masuzawa T; Taenaka Y; Anai H; Wakisaka Y; Eya K; Toda K; Baba Y; Akagi H; Araki K; Nakatani T; Takano H
Korean J Thoracic Cardiovas Surg, Oct. 1994

In vitro and in vivo assessment of an intravenous axial flow pump for right heart assist
Nakatani T; Anai H; Araki K; Wakisaka Y; Taenaka Y; Tatsumi E; Akagi H; Masuzawa T; Baba Y; Eya K; Toda K; Takano H, Right ventricular (RV) function is a limiting factor in maintaining systemic circulation with circulatory assist. There is, however, no easy way to institute RV assist, such as the intraarterial axial flow pump (Hemopump) used for left heart assist. In this study, the feasibility and hemodynamic effect of intravenous use of an axial flow pump was examined. A pump system was developed with an outflow cannula and an impeller that were newly designed for intravenous insertion with a Hemopump driving system. The pump system characteristics using goat blood at a hematocrit of 26% indicated that maximum flow at a pressure differential against 40 mmHg is 3.2 l/min at a pump speed of 28,000 rpm. The pump was tested in adult goats by intravenous insertion through a 14 mm, low porosity graft anastomosed to the infrarenal inferior vena cava. The pump was advanced until the tip of the cannula was positioned at the main pulmonary artery, using balloon catheter guidance under fluoroscopy. RV assistance was evaluated by pressure tracing, and aortic flow (AF) measured by electromagnetic flowmeter under 1) induced pulmonary stenosis (PS), and 2) electrically induced ventricular fibrillation (VF) in, ASAIO Journal
ASAIO Journal, 01 Jul. 1994

Development and evaluation of components for a totally implantable artificial heart system
Y. Taenaka; T. Masuzawa; E. Tatsumi; H. Anai; K. Toda; H. Akagi; T. Nakatani; Y. Baba; K. Eya; Y. Wakisaka; H. Takano; K. Koshiji; E. Shu; T. Utsunomiya; Y. Fukui, The authors have been developing an electrohydraulic (EH) artificial heart system for total implantation. This system consists of intrathoracic ventricles, an abdominally placed EH actuator, flexible silicone oil conduits, externally coupled transcutaneous energy transfer (TET) system, transcutaneous optical telemetry (TOT) system, internal battery, and internal control drive unit. Fitting was evaluated in chronic animal experiments as a pneumatic system in 11 goats weighing 55.2 ± 4.2 kg and 3 calves of 52.3 ± 1.2 kg. The longest survival time in calves was 111 days, and that in goats was 51 days. The assembled EH pump was implanted in two goats of 49 and 50 kg as an acute experiment, and 4.2-6.7 L/min of cardiac output was maintained. For the TET system, an internal coil 3 cm in diameter was implanted to make an arch covered by skin. Electric energy was transmitted from the external to the internal coil, and energy of about 20 W was carried through wires to an external load. The DC-to-DC efficiency of the system was 76-83% for 40 days. The TOT system with internal light emitting diodes and external photodiodes also was evaluated in a goat. Disalignment of up to 12 mm was tolerated. Although more improvement is necessary, most of the components showed characteristics desirable for a totally implantable system., J.B. Lippincott Co
ASAIO Journal, Jul. 1994

遠心ポンプにおけるin-vitro 性能評価
荒木賢二; 妙中義之; 増澤; 徹; 脇坂佳成; 中谷武嗣; 赤城治彦; 馬場雄造; 松尾義昭; 榊; 雅之; 穴井博文; 渡; 正伸.Young; Hwan; Park; 高野久輝
人工臓器, Jun. 1994

Development of full-fill to full-empty drive control system of artificial hearts by measuring electrical impedance in a blood chamber with aoutomatic trigger level adjustment method for ejecting phase.
ANAI H; NAKATANI T; SASAKI E; TAENAKA Y; AKAGI H; MASUZAWA T; BABA Y; ARAKI K; INOUE K; SAKAKI M; MATSUO Y; WATARI M; PARK Yh; TAKANO H, Continuous monitoring method of pump performance by measuring electrical impedance in a blood chamber was applied to the trigger system of full-fill to full-empty(F/E) drive control. An automatic trigger level adjustment method(ATAM) for settlement of a trigger level to change a phase from ejecting to filling was developed to maintain a definite stroke volume against changes of afterload or driving pressure. ATAM was an automatic searching algorism that can identfy the volume change of last ejection by impedance method and settle next trigger level to maintain a destination stroke volume. In a mock circuit and animal experiments, ATAM functioned satisfactorily to follow the changes of afterload and driving pressure and maintained definite stroke volume. In conclusion, this method was practical and useful in regulation of F/E driving., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 1994

A Flow Visualization Study of the NCVC Centrifugal Blood Pump
Kenji Araki; Yoshiyuki Taenaka; Toru Masuzawa; Eisuke Tatsumi; Yoshinari Wakisaka; Masanobu Watari; Takeshi Nakatani; Haruhiko Akagi; Yuzo Baba; Hirofumi Anai; Young Hwan Park; Kazuhiro Eya; Koichi Toda; Hisateru Takano, Abstract: A compact centrifugal pump, NCVC–1, has an open–type impeller with 6 curved vanes, and it is characterized by no shaft and no seal. A tunnel is placed in the center of the impeller–rotor assembly to irrigate the back space behind the rotor. To evaluate the flow, we performed 3 visualization methods: tracer, oil film, and injection streak line method. The flow, observed by the tracer method in NCVC–1, indicated little turbulence along vanes. A volute chamber proved effective to reduce vortex formation in the outlet. Oil film pattern revealed no flow separation on vanes at 5 L/min. Washout flow behind the rotor is essential to prevent thrombus formation and was shown as inward spiral flow without any stagnation. These data suggested that a combination of visualization techniques was useful to analyze various flow conditions, and the NCVC–1 has excellent flow characteristics with little turbulence and little flow stagnation, which must be beneficial to low hemolysis and high antithrombogenicity. © 1994 International Society for Artificial Organs
Artificial Organs, 1994, [Reviewed]

Power of an in-situ latissimus dorsi muscle as an actuator for circulatory assistance
Araki K; Nakatani T; Toda K; Sakaki M; Taenaka Y; Masuzawa T; Akagi H; Baba Y; Matsuo Y; Anai H; Watari M; Park Y, We evaluated the effect of dissecting site and preconditioning which may influence the power generated by an in-situ latissimus dorsi muscle (LDM). To evaluate dissecting sites, 3 un-preconditioned adult goats underwent dissection of the origin of one site and the insertion of the other site. The other 3 adult goats which underwent 10 week-preconditioning were dissected their insertion of LDMs. By contracting muscles under various load, tension-length relationships in end-contraction and end-relaxation and their regression lines were obtained, and the maximum area of a square drawn within both regression lines was assumed to be maximum external work (maxW) of a LDM. The mean maxW generated by the origin-dissected and insertion-dissected LDMs was 0.432 J and 0.732 J, respectively. The power of three preconditioned LDMs changed 0.175 to 0.109 Watts (15 minute-stimulation), 0.137 to 0.094 Watts (60 minutes) and 1.17 to 0.037 Watts (60 minutes) from the beginning to the end of stimulations, respectively. We concluded that the tension-length relationship was useful for evaluation of the generated power of LDMs, and insertion-dissected LDMs could generate higher power than origin-dissect, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1994

Development of full-fill to full-empty drive control system of artificial hearts by measuring electrical impedance in a blood chamber with automatic trigger level adjustment method for ejecting phase
Anai H; Nakatani A; Sasaki E; Taenaka Y; Akagi H; Masuzawa T; Baba Y; Araki K; Inoue K; Sakaki M; Matsuo Y; Watari M; Park Y; Takano H, Continuous monitoring method of pump performance by measuring electrical impedance in a blood chamber was applied to the trigger system of full-fill to full-empty(F/E) drive control. An automatic trigger level adjustment method(ATAM) for settlement of a trigger level to change a phase from ejecting to filling was developed to maintain a definite stroke volume against changes of afterload or driving pressure. ATAM was an automatic searching algorism that can identify the volume change of last ejection by impedance method and settle next trigger level to maintain a destination stroke volume. In a mock circuit and animal experiments, ATAM functioned satisfactorily to follow the changes of afterload and driving pressure and maintained definite stroke volume. In conclusion, this method was practical and useful in regulation of F/E driving., Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1994

An implantable left ventricular assist system with an electrical impedance monitoring and control system
Nakatani T; Anai H; Taenaka Y; Akagi H; Masuzawa T; Baba Y; Sakaki M; Araki K; Inoue K; Matsuo Y; Takano H, The authors developed an implantable left ventricular assist system (LVAS) for bridge to transplant of rather small sized adults. The pump was made of segmented polyether polyurethane and was 86 mm in diameter, 50 mm in height, with a 70 ml nominal stroke volume. A percutaneous drive line was connected with an external pneumatic control drive unit (CDU). In chronic animal experiments using 11 adult goats, the pump was installed between the LV apex and the descending aorta and was placed in the abdominal wall. Five goats were killed after 4 to 14 weeks while in good physical condition, and one is ongoing. There were no prominent thromboembolic symptoms despite no anti- thrombogenic agent being used. The new electrical impedance-based monitoring and control system (Z system) was installed in the CDU. In this Z system, automatic calibration was performed periodically for several seconds while the drive condition was changed to ensure full-fill of the blood pump. The full-fill to full-empty drive was well controlled by this Z system. In conclusion, the new Z system is practical and useful for monitoring and control of an implantable pump, giving this LVAS a promising place in clinical, ASAIO Journal
ASAIO Journal, 29 Oct. 1993

長期使用可能な人工心臓用遠心ポンプの開発－溶血減少のためのインペラ形状変更とその効果－
荒木賢二; 妙中義之; 増澤 徹; 井上和重; 中谷武嗣; 木下正之; 赤城治彦; 馬場雄造; 松尾義昭; 榊 雅之; 穴井博文; 高野久輝, We have developed a centrifugal blood pump for a long-term circulatory assistance, of which final goal is a completely implantable VAD or TAH. NCVC-0 centrifugal blood pump is characterized by non-seal, no shaft, magnet-couple driving and little disturbed flow, resulting in acquiring high durability and anti-thrombogenicity. To achieve an improvement of a pumping performance and hemolytic properties, the impeller of NCVC-0 was modified to that of NCVC-1; the profile shape was changed from flat to conical, the number of vanes from 4 to 6, the vane entrance angle from 30 to 60 degrees and the height was made wider. These modifications resulted that the revolution number to generate 100mmHg and 5L/min was decreased from 2850rpm of NCVC-0 to 2450rpm of NCVC-1 and that the hemolytic index was decreased to 0.013g/100L for NCVC-1 compared with 0.039g/100L for NCVC-0. We concluded that NCVC-1 centrifugal pump acquired a sufficient pumping performance and hemolytic property in addition to high durability and anti-thrombogenicity which were inherited by NCVC-0., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Jun. 1993

体内完全埋込型を目指したエレクトロハイドローリック式全人工心臓の急性動物実験による性能評価
妙中義之; 木下正之; 増澤 徹; 中谷武嗣; 赤城治彦; 榊 雅之; 松尾義昭; 井上和重; 馬場雄造; 穴井博文; 荒木賢二; 高野久輝; 藤田 毅, In vivo performance of an electrohydraulic total artificial heart was evaluated in acute experiments aiming at the establishment of a totally implantable system. The device consists of diaphragm-type ventricles and an electrohydraulic actuator placed in the abdominal region. The device was implanted in 2 goats of 50 and 49kg to evaluate anatomical fitting, surgical implantation procedure and hemodynamic performances. The pump fit well in the chest cavity and there was no difficulty in surgical procedure. An atrial septal defect was made to compensate the right to left imbalance of cardiac output. Hemodynamic parameters were maintained within a normal range, including atrial pressure, cardiac output, aortic pressure and pulmonary arterial pressure. The results indicated satisfactory in vivo performance of the artificial heart for future development of a totally implantable system., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Jun. 1993

A FLOW VISUALIZATION STUDY OF CENTRIFUGAL BLOOD PUMPS DEVELOPED FOR LONG-TERM USAGE
K ARAKI; Y TAENAKA; T MASUZAWA; K INOUE; T NAKATANI; M KINOSHITA; H AKAGI; Y BABA; Y MATSUO; M SAKAKI; H ANAI; H TAKANO, We have developed centrifugal pumps for long-term circulatory assistance, with the final goal of a completely implantable ventricular assist device or total artificial heart. The previous model, NCVC-0, was characterized by a nonseal design and few flow-stagnating parts and acquired high durability and antithrombogenicity. To improve its pumping performance, NCVC-0 was modified. In the new model, NCVC-1, the profile shape of the impeller was changed from flat to conical, the number of vanes from 4 to 6, and the vane entrance angle from 30-degrees to 60-degrees. A flow visualization study performed by means of a combination of the polystyrene tracer method and the light-cutting method indicated decreased flow turbulence between vanes in NCVC-1, which corresponded well with the increased pumping performance. Flow visualization is a useful method to evaluate the design elements that are closely related to the pumping performance of a centrifugal blood pump., BLACKWELL SCIENCE INC
ARTIFICIAL ORGANS, May 1993

Effect of cardiomyoplasty on ventricular function with our compact electrical stimulator.
SAKAKI M; NAKATANI T; ARAKI K; TAENAKA Y; KINOSHITA M; AKAGI H; MASUZAWA T; BABA Y; MATSUO Y; INOUE K; ANAI H; TAKANO H; OTA M; FUJITA T; MOROE T, The purpose of the study is to clarify the effect of cardiomyoplasty on ventricular function, especially on right ventricular function. The experiment was performed with the left latissimus dorsi muscle (LDM) in 4 normal heart goats. After electrically conditioned for 6 to 8 weeks, the pedicled LDM were sutured around the ventricles clockwise and stimulated synchronously with our compact electrical stimulator. Our stimulator showed a good quality during the experiment To evaluate the ventricular function, systolic pulmonary arterial pressure (sPAP), right ventricular ejection fraction (RVEF), cardiac output (CO), systolic left ventricular pressure and maximal end-systolic volume elastance (Ees) with and without stimulation were measured. Although no significant changes were observed in these data, sPAP (29±3 mmHg vs 26±3 mmHg), RVEF (42±8% vs 37±8%) and CO (6.0±0.7 L/min vs 5.3±1.4 L/min) showed a tendency to increase. We considered that cardiomyoplasty with electrically conditioned LDM could play an important part to improve the right ventricular function., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
Journal of the Japanese Society for Artificial Organs and Tissues, 1993

Cardiac output estimation model with a neural network toward total artificial heart control　　　　　　　　　　　　　　　
Toru Masuzawa; Yoshiyuki Taenaka; Masayuki Kinoshita; Takeshi Nakatani; Haruhiko Akagi; Hisateru Takano; Yasuhiro Fukui, A computer neural network model to estimate cardiac output from physiological data during exercise was developed toward studying total artificial heart (TAH) control. Treadmill exercise test was given to two normal goats to obtain the physiological data during exercise. Heart rate, mean arterial blood pressure, mixed venous oxygen saturation and physical activity were adopted in the neural network as input variables and cardiac output was used as an output variable. A three layer back-propagation network was used to construct the model. Feasibility of the neural network for modeling was evaluated by comparing estimated cardiac output and real data. Estimated cardiac output agreed well with real cardiac output with the individual data. The neural network technique should be a useful tool to develop control algorithm of TAH., Publ by IEEE
Proceedings of the Annual Conference on Engineering in Medicine and Biology, 1993

Diastolic mechanics of a skeletal muscle pump system actuated by in-situ bilateral latissimus dorsi muscles
Araki K; Nakatani T; Sakaki M; Matsuo Y; Taenaka Y; Kinoshita M; Masuzawa T; Akagi H; Baba Y; Inoue K; Anai H; Takano H, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1993

In vivo performance of an electrohydraulic total artificial heart toward the development of a totally implantable system
Taenaka Y; Kinoshita M; Masuzawa T; Nakatani T; Akagi H; Sakaki M; Matsuo Y; Inoue K; Baba Y; Anai H; Araki K; Takano H; Fujita T, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 1993

The development of a centrifugal blood pump for a long-term usage - Modifications of the impeller and its effect on the hemolytic property
Araki K; Taenaka Y; Masuzawa T; Inoue K; Nakatani T; Kinoshita M; Akagi H; Baba Y; Matsuo Y; Sakaki M; Anai H; Takano H, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1993

Development of continuous monitoring and control system of artificial heart by measuring electrical impedance in a blood chamber with automatic calibration mechanism
Anai H; Nakatani T; Sasaki E; Taenaka Y; Kinoshita M; Akagi H; Masuzawa T; Baba Y; Sakaki M; Inoue K; Matsuo Y; Araki K; Takano H, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1993

A new ventilator system for liquid breathing driven by a linear motor
Baba Y; Taenaka Y; Tsukahara K; Akagi H; Nakatani T; Kinoshita M; Masuzawa T; Sakaki M; Inoue K; Matsuo Y; Anai H; Araki K; Ohumi T; Takano H, Japanese Journal of Artificial Organs
Japanese Journal of Artificial Organs, 01 Jan. 1993

A model of cardiovascular system using a neural network technique
MASUZAWA T.; KINOSHITA M.; TAENAKA Y.; NAKATANI T.; AKAGI H.; TAKANO H., A model of the cardiovascular system was developed using a neural network technique. A treadmill exercise experience was performed to obtain the physiological signals during the exercise with a goat. The blood pressure catheter and blood flow prove were implanted in the chest and the exercise tests were performed after two weeks of the operation. The model to estimate cardiac output from heart rate, mean arterial pressure, mixed venous saturation and physical activity that were obtained from the exercise experience was constructed based on a neural network technique. A three-layer back-propagation network, which has the input layer with forty two cells, the hidden layer with thirty two cells and the output layer with 10 cells, was used to construct the model. Five hundred and forty six sets of data were used for learning process of the network. Seventy sets of the learning data and sixty six sets of data which were not used for learning were used to evaluate the performance of the cardiac output estimation. The correlation coefficient between the learning data and real cardiac output was 0.965 (p<0.001) and that for the non-learning data was 0.869 (p<0.001) and the feasibility of the neural network for modeling of cardiovascular system was confirmed., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, 1993

A bioartificial ventricle used as a totally implantable circulatory assist device
Takeshi Nakatani; Akio Kishida; Takehisa Matsuda; Masayuki Sakaki; Masahiro Goto; Yoshiyuki Taenaka; Masayuki Kinoshita; Haruhiko Akagi; Toru Masuzawa; Yuzo Baba; Kenji Araki; Kazushige Inoue; Hirohumi Anai; Yoshiaki Matsuo; Hisateru Takano, The authors designed a totally implantable circulatory assist device consisting of a bioartificial ventricle composed of a skeletal muscle ventricle lined with a bioartificial endocardium. The bioartificial endocardium consists of a structural matrix made of a polyurethane porous membrane, fragmented blood vessels, and collagen gel. The authors prepared the polyurethane porous membrane by solvent cocasting with salt powder. They used collagen gel with fragmented goat carotid vein to perform in vitro construction of the bioartificial endocardium. For in vivo construction of the bioartificial endocardium, the authors used a modified version of the tissue fragment method for vascular prostheses. The authors prepared suspensions of tissue fragments using collagen gel with fragmented goat carotid artery. They used a highly porous fabric vascular prosthesis as a structural matrix
tissue fragments were entrapped on the outer surface of the prosthesis, and the prosthesis then was implanted into the carotid artery of four adult goats. In specimens 1 and 3 months postimplantation, cells from the fragmented tissue regenerated an endothelium-like monolayer sheet on the inner surface of the prostheses. Output of a prototype bioartificial ventricle reached 660 ml/min at an afterload of 60 mmHg and a preload of 20 mmHg. Based on these data, the authors conclude that the bioartificial ventricle is promising as an implantable device with excellent antithrombogenicity.
Trans Am Soc Artif Intern Organs, Jul. 1992

Pulmonary function in a non-pulsatile pulmonary circulation
Masayuki Sakaki; Yoshiyuki Taenaka; Eisuke Tatsumi; Takeshi Nakatani; Masayuki Kinoshita; Haruhiko Akagi; Toru Masuzawa; Yoshiaki Matsuo; Kazushige Inoue; Yuzo Baba; Hirohumi Anai; Kenji Araki; Hisateru Takano Tsutomu Kasugai, The authors suggested that a mammal immediately accommodates well to nonpulsatile flow in the systemic circulation. In the current study, nonpulsatile pulmonary blood flow using a centrifugal pump was established in chronic models to analyze its influence on the pulmonary circulation. A pulsatile right ventricular assist device (RVAD) was implanted to draw blood from both the right atrium and ventricle and send blood to the pulmonary artery in six goats. After 2 weeks, the pulsatile pump was quickly replaced with a centrifugal pump without anesthesia, and a 100% non-pulsatile pulmonary blood flow was obtained. Cardiac output was kept at 80-120 ml/kg/min during the experiments. No changes were observed in hemodynamic ters, including pulmonary arterial pressure, pulmonary vascular resistance index, and blood gas data, after the immediate depulsation of the pulmonary blood flow. There was also no significant change in the ventral to dorsal tissue blood flow ratio of the lower lobe of the right lung, which was calculated by a colored microsphere method, between pulsatile and non-pulsatile pulmonary blood perfusion. These results suggest that pulmonary function, including blood flow distribution, is not affected by non-pulsatile pulmonary circulation for periods up to 14 days.
Trans Am Soc Artif Intern Organs, Jul. 1992

Permeation of silicone oil through a diaphragm in an electrohydraulic ventricular assist system
Yoshiaki Matsuo; Yoshiyuki Taenaka; Hisateru Takano; Takeshi Nakatani; Toru Masuzawa; Haruhiko Akagi; Masayuki Kinoshita; Yuzo Baba; Masayuki Sakaki; Takeharu Ohumi; Kinji Tsukahara; Katsuya Tsuchimoto; Tetsuzo Akutsu, This study was designed to investigate the permeation of silicone oil through a pump diaphragm made of Pellethane in the authors' electrohydraulic ventricular assist system (EHVAS) and to evaluate influences on organ function. The permeability of the diaphragm to silicone oil was investigated by in vitro experiments. Influences on organ function were evaluated in five goats with an EHVAS by monitoring serum silicon levels (SSi), blood chemical parameters, and histologic findings. Elevation of silicone oil levels in Pellethane sheets immersed in silicone oil demonstrated that the Pellethane diaphragm was, in fact, permeable to silicone oil. The permeation rate of silicone oil was calculated to be 1.75 ml/year in the authors' EHVAS from the data of a diffusion apparatus test. Serum silicon levels did not increase during the EHVAS pumping, and renal and hepatic function were not affected. No abnormality or deposit suggestive of silicone oil was observed. However, the problem of permeation of silicone oil through the pump diaphragm must be solved to allow for a circulatory assist device for long-term use.
Trans Am Soc Artif Intern Organs, Jul. 1992

Influence of an impeller centrifugal pump on blood components in chronic animal experiments
Yoshiyuki Taenaka; Kazushige Inoue; Toru Masuzawa; Kenji Araki; Masayuki Sakaki; Yoshiaki Matsuo; Haruhiko Akagi; Takeshi Nakatani; Masayuki Kinoshita; Yuzo Baba; Hirifumi Anai; Hisateru Takano, A chronic animal experiment was designed to examine the changes in blood components induced by the use of a centrifugal pump (CP). In the pump, an impeller spins in a blood chamber by magnetic coupling with a rotating magnet outside the blood chamber. A pulsatile ventricular assist device was implanted between the left atrium and the descending aorta in four goats weighing from 63 to 75 kg
the CP was installed to replace the assist device, without surgery and anesthesia, more than 2 weeks later when the influences of implantation surgery were diminished. Antithrombotic therapy was performed with oral administration of an antiplatelet agent, cilostazol, a cyclic adenosine monophosphate phosphodiesterase at a dose of 30 mg/kg/day. No significant differences were observed in any of the following parameters: 1) hematocrit, 2) plasma free hemoglobin, 3) lactic acid dehydrogenase, 4) adenosine diphosphate, 5) platelet count, 6) fibrinogen, and 7) antithrombin III, between the data before and after the use of the CP, nor were deformation or pseudopods of platelets seen. The CP developed in the authors' institute and evaluated in this study did not damage blood components, and it proved to be a promising device for long-term use.
Trans Am Soc Artif Intern Organs, Jul. 1992

小型多機能補助循環駆動装置の開発
中谷武嗣; 佐々木栄作; 穴井博文; 妙中義之; 木下正之; 巽英介; 増澤徹; 赤城治彦; 後藤昌弘; 松尾義昭; 榊雅之; 井上和重; 馬場雄造; 高野久輝; 近城賢一; 橋本浩一; 池田稔, We have built a new compact control drive unit (CDU) which can be used for a ventricular assist system (VAS) or intraaortic balloon pumping (IABP). This CDU has an installed air compressor, a vacuum unit, a battery, full alarm and backup systems, an automatic level control of flow and atrial pressure for VAS, and a full-fill to full-empty drive mode controlled by air flow. This CDU exhibited satisfactory and stable performance in mock circulation, animal studies and clinical cases. This new compact CDU is thought to be useful in clinical setting., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Apr. 1992

無拍動流肺循環の肺におよぼす影響に関する実験的検討－慢性期，覚醒状態下において－
榊雅之; 妙中義之; 巽英介; 中谷武嗣; 赤城治彦; 増澤徹; 後藤昌弘; 佐々木栄作; 井上和重; 松尾義昭; 馬場雄造; 穴井博文; 高野久輝, As a centrifugal pump was widely used for eltracorporeal circulation in recent years, the clarification of the influences of nonpulsatile blood flow on physiological function has become more important, especially in pulmonary function. To analyze the influences, nonpulsatile pulmonary blood flow by a centrifugal pump was established in chronic animal models. A pulsatile RVAS was implanted to draw the blood from both the right atrium and ventricle and to send to the pulmonary artery in 4 goats. Two weeks after implanted, the pulsatile pump was quickly replaced by a centrifugal pump without anesthesia and a 100% nonpulsatile pulmonary blood flow was obtained. Cardiac output was kept at 80-120 ml/kg/min during the experiments and no changes were observed in hemodynamic parameters after the immediate depulsation of the pulmonary flow. Blood gas data and serum levels of angiotensin converting enzyme were maintained within normal range. There was no significant change in the ventral to dorsal blood perfusion ratio of the lower lobe of right lung which was calculated by the colored microsphere method, between pulsatile and nonpulsatile pulmonary flow. These results suggested that pulmonary functions including gas exchange and metabolism of vasoactive agent and lung tissue perfusion were not affected by nonpulsatile pulmonary circulation., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Apr. 1992

左室圧－容積関係を用いたcardiomyoplastyの左心補助効果に関する実験的検討
後藤昌弘; 中谷武嗣; 榊雅之; 妙中義之; 巽英介; 赤城治彦; 増澤徹; 佐々木栄作; 馬場雄造; 松尾義昭; 井上和重; 藤田毅; 高野久輝, Cardiomyoplast (CMP) has been performed for heart failure patients. The evaluation of cardiac function under CMP, however, was difficult and the performance of CMP was unclear in clinical cases. In order to clarify the effect of CMP, we applied left ventricular pressure-volume loops relationship using a conduct-ance catheter (CC) in acute animal expert-ments. In normal heart goats (n=5), electrically preconditioned latissimus dorsi muscle flap (LDMF) was sutured around the ventricle counterclockwise and was stimulated synchronously by the electrical stimulator with bursts. The left ventricular volume was measured using a CC with and without LDMF stimulation. Maximal end-systolic volume elastance (Ees) was determined from multiple pressure-volume loops obtained during a brief preload reduction by occlusion of an inferior vena cava. There are no significant differences in Ees, stroke volume, left ventricular(LV) end-diastolic pressure, LV end-systolic pressure and end-diastolic volume between, with and without LDMF stimulation. These data showed that the CMP did not affect LV performances of normal heart in goats. However, a CC was useful to evaluate LV functions and to avoid the limitation of cardiac diastolic movement with CMP., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Apr. 1992

胎盤を用いたハイブリッド型呼吸補助システムの試作
赤城治彦; 高野久輝; 妙中義之; 中谷武嗣; 木下正之; 馬場雄造; 巽英介; 増澤徹; 後藤昌弘; 井上和重; 榊雅之; 松尾義昭; 穴井博文; 荒木賢二, A novel hybrid respiratory support system was developed using a human placenta. In this system, patient's blood is oxygenated with 02 saturated artificial blood across villous membrane during passage through the fetal circuit of a placenta which is placed in a specially constructed artificial uterus. Human term placentas were obtained immediately after vaginal delivery and served for experiments. The gas transfer performance of the system was 60 ml/min for O₂ and 40 ml/min for CO₂ at a blood flow rate of 1l/min. From these results and assured antithrombogenicity of the placenta, we conclude that this system will become one of the most promising modalities for prolonged extracorporeal oxygenation without anticoagulant., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Apr. 1992

Cardiovascular simulation using a multiple modeling method on a digital computer-Simulation of interaction between the cardiovascular system and angiotensin II (jointly authored)
T MASUZAWA; Y FUKUI; NT SMITH, A cardiovascular system model that simulates interactive responses to drugs has been developed on a small digital computer. The overall model basically consists of three models. The first is a momentum transport model that represents relations between blood pressure and flow in the cardiovascular system. In this model, the cardiovascular system is divided into 14 components and modeled by using equivalent electrical circuits. The second is a mass transport model comprising 14 compartments corresponding to the respective components of the cardiovascular system. This model represents the distribution of the administered drug in the various cardiovascular components. The third is an interaction model that represents the relationships between the momentum and mass transport models. This model causes variations in the resistance and capacitance parameters of the momentum transport model as a function of the current drug concentrations in the appropriate compartments of the mass transport model. The capacitances representing the ventricles are varied in a time-dependent fashion to simulate the beat of the heart. Simulation is performed by using the Euler method to solve a system of 28 ordinary differential equations governing the momentum and mass transport models on a 32-bit microcomputer, a Macintosh II. The model was assessed by performing two demonstrations of the cardiovascular response to the vasopressor angiotensin II (AT II). They first examined the interaction between the cardiovascular system and AT II. The effect of AT II on the cardiovascular system was incorporated into the interaction model. Administration of AT II as a constant infusion (200-mu-g/hr) resulted in an elevation of mean arterial pressure from approximately 100 to 150 mm Hg. The second was a pharmacodynamic demonstration of the cardiovascular system in the presence of tumor tissue during induced-hypertension chemotherapy. A tumor tissue component was added to the cardiovascular system model, thereby incorporating into the interaction model the effects of blood pressure elevation on tumor tissue. The same administration of AT II as above resulted in an increase in blood flow from 0.3 and 1.3 ml/s (i.e., an increase of approximately 460%) in the carcinomatous tissue. The results, along with those obtained earlier with sodium nitroprusside, indicate that the present simulator could represent the cardiovascular system during administration of vasoactive drugs., KLUWER ACADEMIC PUBL
Journal of Clinical Monitoring, 1992

A motor integrated regenerative pump as the actuator of an electrohydraulic totally implantable artifical heart. (jointly authored)
T. Masuzawa; Y. Taenaka; M. Kinoshita; T. Nakatani; H. Akagi; H. Takano; Y. Fukui; H. Sasagawa; K. Takahashi, The authors have developed a new actuator to drive an electrohydraulic totally implantable artificial heart. The basic concept of this artificial heart is that the blood pumps are implanted in the thorax and an actuator is placed separately in the abdominal region. The actuator is a regenerative pump that pumps fluids against high pressures and is thin enough for easy implantation. The rotor-magnet of the brushless DC motor is mounted on the impeller of the pump to miniaturize the actuator and reduce the number of moving parts. The height, diameter, and weight of the actuator are 32.5 mm, 73 mm, and 360 g, respectively. A pair of oil ports is connected to the left and right blood pumps with mesh reinforced tubes filled with silicone oil. The blood pumps are alternately driven by bidirectional rotation of the motor. Performance of the system was evaluated in in vitro and in vivo experiments. Maximum output of the right heart was 6.7 L/min in both experiments. Systemic circulation was well maintained in acute animal experiments using 49 and 50 kg goats. The feasibility of the actuator was confirmed.
Trans Am Soc Artif Intern Organs, 1992

腹壁内埋込み型左心補助人工心臓に関する基礎的検討
中谷武嗣; 後藤昌弘; 妙中義之; 巽英介; 赤城治彦; 佐々木栄作; 増澤徹; 松尾義昭; 関井浩義; 矢倉明彦; 高野久輝, As the initial stage of development of implantable left ventricular assist system (VAS), the blood pump system was designed to be positioned in the left abdominal wall. The pump is a pneumatic and diaphragm-type modified from NCVC VAS made of Japanese-made segmented polyether polyurethane. Inflow cannula was reinforced at the distal portion. The pump was connected by inflow and outflow cannulae between the left ventricular apex and the descending aorta, and was connected to the external console by a percutaneous tube. In animal experiments using goats, this system showed easy applicability and stable hemodynamics over three weeks. There was no signs of infection around the pocket of pump. In conclusion, this blood pump system is safely applicable to long-term left ventricular assist., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Aug. 1991

Serum silicon levels in recipients of an electrohydraulic ventricular assist system
Yoshiaki Matsuo; Yoshiyuki Taenaka; Hisateru Takano; Takeshi Nakatani; Eisuke Tatsumi; Toru Masuzawa; Masahiro Goto; Akihiko Yagura; Haruhiko Akagi; Eisaku Sasaki; Kazusige Inoue; Masayuki Sakaki; Yuzo Baba; Tetsuzou Akutsu; Takeharu Ohumi; Kinji Tsukahara, This study was designed to determine the permeation rate of silicon oil from the authors' electrohydraulic ventricular assist system (EHVAS), and to evaluate influences on organ function. The permeation rate through the diaphragm of the EHVAS was determined by in vitro experiments. Influences on organ function were evaluated in three goats with EHVAS by monitoring blood chemical parameters and serum silicon levels (S-Si). The permeation rate from the EHVAS was about 0.2 ml/month, calculated from the data obtained in the in vitro experiments. S-Si levels did not increase during chronic animal implantation, and renal and hepatic function were not affected. The permeation rate through the diaphragm must, however, be taken into consideration.
ASAIO Transactions, Jul. 1991, [Reviewed]

Chronic evaluation of a compact nonseal magnet pump as a nonpulsatile pump for long-term use
Yoshiyuki Taenaka; Eisuke Tatsumi; Masayuki Sakaki; Eisaku Sasaki; Toru Masuzawa; Takeshi Nakatani; Haruhiko Akagi; Masahiro Goto; Yoshiaki Matsuo; Kazushige Inoue; Yuzo Baba; Masayuki Kinoshita; Hisateru Takano, Use of a nonpulsatile pump is one of the most interesting approaches in the development of artificial hearts. A centrifugal pump without a seal around the rotating part was evaluated in five goats. The size of the pump is 8.4 cm ×φ7.0 cm, including an electric motor. A polypropylene impeller with four fins on the top of a column in which a magnetic ring is embedded spins by coupling with a rotating magnet outside the housing. In the goats, the pump was placed paracorporeally to provide total left heart bypass at a flow rate of 4.6-7.6 L/min, and activated clotting time was controlled at 200-300 sec by continuous heparin infusion. Although the first three goats died within 3 days due to bleeding, embolism, and a jammed impeller, respectively, a pump could be driven for 14 days in the fourth goat, and another pump with a rotational control feedback system ran for 32 days in the fifth goat. Plasma free hemoglobin levels were 13.8 ± 4.3 mg/dl and 9.5 ± 2.5 mg/dl, and platelet counts were 53.8 ± 24.7 × 104/mm3 and 62.0 ± 22.0 × 104mm3 after 12 hours and 7 days pumping, respectively. No thrombus was observed in the blood chamber in the last two cases. In conclusion, this pump has possibilities as a nonpulsatile pump for long-term use.
ASAIO Transactions, Jul. 1991, [Reviewed]

Peripheral circulation during nonpulsatile systemic perfusion in chronic awake animals
Yoshiyuki Taenaka; Eisuke Tatsumi; Masayuki Sakaki; Eisaku Sasaki; toru Masuzawa; Takeshi Nakatani; Haruhiko Akagi; Masahiro Goto; Yoshiaki Matsuo; Kazushige Inoue; Yuzo Baba; Masayuki Kinoshita; Hisateru Takano, Peripheral circulation (PC) during nonpulsatile (NP) perfusion is not satisfactorily understood, although it is known that animals can survive with chronic NP flow. In awake goats, PC was analyzed by hemodynamic and hormonal parameters, tissue blood flow of the ear measured by a noninvasive laser Doppler flowmeter, and distribution of the body surface temperature monitored by thermography. An NP systemic circulation was established in five 40-64 kg goats with a centrifugal pump (MD-10, Iwaki Pump, Japan) that replaced a pulsatile ventricular assist device 2 weeks postoperatively
this was done without anesthesia. Nonpulsatile total left heart bypass was obtained, with flow rates of 78-165 ml/kg/min. Systemic vascular resistance and blood adrenalin and noradrenalin levels were not affected by the depulsation. Tissue blood flow during NP perfusion was well maintained and showed comparable values to those during pulsatile systemic circulation. Vasomotion of 10-20 cycles/min was obvious in the tissue blood flow pattern, indicating adequate PC at each sampling point. Thermography before and after depulsation indicated no change of temperature distribution, and displayed warm peripheral areas. In conclusion, PC of animals on chronic NP systemic perfusion is adequately maintained.
ASAIO Transactions, Jul. 1991, [Reviewed]

Hybrid respiratory support system with extracorporeal placental oxygenation
Haruhiko Akagi; Hisateru Takano; Yoshiyuki Taenaka; Takeshi Nakatani; Eisuke Tatsumi; Toru Masuzawa; Masahiro Goto; Eisaku Sasaki; Kazushige Inoue; Masayuki Sakaki; Yoshiaki Matsuo; Yuzo Baba, The authors developed a novel hybrid system for long-term respiratory support with extracorporeal placental oxygenation. In this system, the patient's blood is oxygenated with O2 saturated artificial blood across the villous membrane during passage through the fetal circuit of the placenta, which is placed in a specially constructed artificial uterus. Human term placentas were obtained immediately after vaginal delivery and used for the experiments. The gas transfer performance of the current apparatus was 60 ml/min for O2 and 40 ml/min for CO2 at a blood flow rate of 1.0 L/min. From these results (and the assured blood compatibility of the placenta), the authors conclude that this system will become one of the most promising modalities for prolonged extracorporeal oxygenation.
ASAIO Transactions, Jul. 1991, [Reviewed]

Integrated artificial heart-lung device
Eisuke Tatsumi; Hisateru Takano; Yoshiyuki Taenaka; Haruhiko Akagi; Takeshi Nakatani; Eisaku Sasaki; Masahiro Goto; Toru Masuzawa; Masayuki Sakaki; Yoshiaki Matsuo; Kazushige Inoue; Jun Kamo; Takanobu Aoyagi, An integrated artificial heart-lung device (IAHLD) is being developed as a novel system for simultaneous long-term support of heart and lung. The IAHLD consists of an artificial lung component (LC) and two blood pumps. The LC is made with a special composite hollow fiber membrane that prevents serum leakage. The fibers are arranged as piled-up lattices and potted in a cylindrical housing made of polyurethane. The blood pump with a single port is of a pneumatic pusher-plate type, and a Bjoerk-Shiley valve is mounted in the port. The LC is sandwiched between the inlet and outlet pumps, and all components are integrated. This special structure provides high gas exchange efficiency, prevention of flow channeling and stagnation, and reduction of blood contacting surfaces. The prototype IAHLD had exchange rates of up to 170 ml/min of O2 and CO2 and up to 5.5 L/min of pump output. A flow visualization analysis with cineroentgenography revealed that the flow distribution within the IAHLD was uniform, without any stasis. It was concluded that the IAHLD is a promising system for long-term heart and lung support, and can be used without systemic heparinization given thromboresistant surface treatment as the next step of development.
ASAIO Transactions, Jul. 1991, [Reviewed]

完全体内埋込型エレクトロハイドローリック式全人工心臓の開発のための基礎的検討
妙中義之; 増澤 徹; 中谷武嗣; 矢倉明彦; 巽 英介; 関井浩義; 佐々木栄作; 赤城治彦; 後藤昌弘; 榊 雅之; 松尾義昭; 井上和重; 高野久輝, An electro-hydraulic total artificial heart system consisted of a separately placed actuator and blood pumps was designed. In the actuator a brushless DC motor is sandwiched by 2 pusher-plate pumps connected with the blood pumps by flexible tubes. A roller-screw system is employed for alternative pumping and silicone oil is used to trans-mit the action. The pumps were implanted in 4 goats of 54-59 kg as a pneumatic sys-tem. The longest survivor could be maintained for 40 days. The system could yield around 6L/min in an in vitro evaluation., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, Jun. 1991

補助人工心臓からの離脱に有用な新しい駆動法を搭載した多機能補助循環駆動装置の開発と評価
佐々木栄作; 中谷武嗣; 高野久輝; 妙中義之; 巽英介; 赤城治彦; 関井浩義; 矢倉明彦; 後藤昌弘; 増澤徹; 榊誠之; 松尾義昭; 池田稔, We have built a new drive unit (VCT200) which can drive both IABP and LVAS in the same way as separate units. And we devised a new weaning method, Alternate Synchronous Driving (ASD), to wean from LVAS to IABP smoothly. ASD was installed in VCT200 to be applied easily and automatically. After IABP insertion in the final weaning stage, ASD drives LVAS and IABP alternately, with electrocardiogram synchronization. The pumping ratio of IABP increases while that of LVAS decreases according to the recovery of natural heart function. In vitro and in vivo studies, ASD was effective method to prevent hemodynamic deterioration during final weaning from LVAS and overlap in pump ejection and balloon inflation., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, 1991

エレクトロハイドローリック方式補助人工心臓システムの改良と慢性動物実験による性能評価
松尾義昭; 矢倉明彦; 妙中義之; 高野久輝; 中谷武嗣; 巽英介; 赤城治彦; 関井浩義; 佐々木栄作; 後藤昌弘; 増澤徹; 榊雅之; 阿久津哲造; 大海武晴; 土本勝也, We estimated the EHVAS in 4 goats and examined the effect of the automatic negative pressure control (ANPC) mechanism to prevent atrial wall sucking. ANPC regulates the filling power of the actuator automatically by monitoring sillicone oil pressure. Our EHVAS could be operated for 21-42 days. When ANPC was not used, instantaneous left atrial pressure during filling phase was-40mmHg, however, it was-10mmHg by using ANPC. ANPC could prevent atrial wall sucking. Our EHVAS could become a portable VAS., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, 1991

実験動物の無拍動流体循環への生理学的適応過程の検討
妙中義之; 巽英介; 榊雅之; 佐々木栄作; 中谷武嗣; 赤城治彦; 関井浩義; 矢倉明彦; 後藤昌弘; 増澤徹; 松尾義昭; 井上和重; 高野久輝, A pulsatile left ventricular assist device was quickly replaced by a centrifugal pump without anesthesia in 5 goats 2 weeks after surgery. A 100% bypass of nonpulsatile systemic flow was immediately obtained and the pump was controlled to maintain the same mean aortic pressure as before the switch. Central venous pressure, cardiac output, systemic vascular resistance, oxygen consumption, blood lactate, and plasma adrenalin, noradrenalin, renin activity, angiotensin II and aldosterone did not deviate from the control levels., JAPANESE SOCIETY FOR ARTIFICIAL ORGANS
人工臓器, 1991

The blood pressure control system with abnormal control phase recognition
MASUZAWA Toru, A study is presented of a blood pressure control system with safety feature in therapeutic practice. Using fuzzy logic, the physician's heuristic rules for control were transformed into automatic control rules. Fuzzy controller has two input variables (the difference between the actual and target pressures, the increment of blood pressure) and one output variable (the variation in the drug dosage) expressed as a fuzzy variable by establishing corresponding membership functions. 25 control rules were converted into fuzzy control rules. As safety feature, the control phases recognition function was developed by using TMSTR (Time-sequential Multiple State Transition Representation) technique which is devised to represent time-sequential data transition with IF-THEN rule structure. The function is observing time-trend of blood pressure and drug infusion rate during control. The function takes over control from the fuzzy controller when abnormal control phases are recognized. To evaluate the present system, the pressure elevation simulation and animal experiments were performed. The blood pressure was elevated from the ordinary level (about 100 mmHg) to 150 mmHg by infusing the vasopressor. Excellent blood pressure control was achieved in both of simulation and experiments, and the overall effectiveness of the present control system was verified., The Japan Society for Precision Engineering
精密工学会誌, Aug. 1990

A control method based on recognition of time sequential data transition–application to blood pressure control
Toru Masuzawa; Yasuhiro Fukui, The development of an automatic system which, as a means of treatment, can control the blood pressure of a patient by a continuous injection of vaso‐acting drugs is in great demand in the medical care field. However, the practical application of such a system has been postponed due to safety considerations. This paper attempts to realize the safe control of the physiological system, and a control method based on the recognition of the transition of the time‐series signal has been developed. The idea is applied to the automatic control of blood pressure. For the recognition of the time‐series signal transition, a dedicated IF‐THEN representation TMSTR (time‐sequential multiple state transition representation) is devised which includes the concepts of “state” and “time.” A method is proposed in which more than one “state” is defined for the time‐sequential data, and the transitions among states are represented by IF‐THEN rules. By this scheme, the time sequential data transition is recognized. Using the constructed representation, the physician's knowledge of the blood pressure control is represented and transplanted to the computer. Using a 16‐bit microcomputer, a closed‐loop control system is constructed. As a result of animal experiments, a blood pressure control close to that of the physician is realized, indicating the effectiveness of the proposed method in the control of the physiological system. Copyright © 1990 Wiley Periodicals, Inc., A Wiley Company
Systems and Computers in Japan, 1990

An electorohydraulic total artificial heart with a separately placed actuator
Y.Taenaka; H.Sekii; E.Tatsumi; T.Nakatani; E.Sasaki; A.Yagura; H.Akagi; T.Masuzawa; M.Goto; Y.Matsuo; And H.Takano, An electrohydraulic total artificial heart (EHTAH) system, consisting of a separately placed actuator and blood pumps with good anatomic fit, was designed. In the actuator is a brushless DC motor sandwiched between two metal bellows or two pusher-plate pumps connected with the blood pumps by polyvinylchloride tubes. A roller-screw system coupled with the bellows is used for alternative pumping, and silicone oil transmits the action. The pumps are elliptical, and the right pump has a flatter and longer shape than the left to fit the extremely short distance between the right atrium and the sternum. To evaluate in vivo performance, the pumps were implanted as a pneumatic system in a calf weighing 53 kg and three goats weighing 54-55 kg. The pump fit well in the animals, and the calf survived for 111 days, and one goat was alive for 8 days. The EHTAH system could provide an output of 6 L/min with pusher-plate pumps as oil chambers on in vitro evaluation. This system could become one of the most suitable approaches for a totally implantable system.
ASAIO Transaction, 1990

時系列信号の推移認識に基づいた制御－血圧自動制御への応用－
増澤 徹; 福井康裕, 電子情報通信学会情報・システムソサイエティ
電子情報通信学会論文誌ＤⅡ, Nov. 1989

Knowledge-based approach to intelligent alarms
Yasuhiro Fukui; Toru Masuzawa, The goal of intelligent alarms is not only to recognize potentially dangerous situations, but to discriminate whether the condition is truly threatening or has resulted from nonthreatening causes, such as artifacts. The authors describe a knowledge-based approach in the development of intelligent alarms, using complex guidelines that simulate human reasoning and follow "if, then" rules of problem solving. © 1989 Little, Brown and Company., Kluwer Academic Publishers
Journal of Clinical Monitoring, Jul. 1989

ファジィ血圧制御システムの開発
福井康裕; 増澤 徹
医用電子と生体工学, Jun. 1989

介助用小型軽量マニプレータの開発
藤記拓也; 土肥健純; 増澤 徹, In these several years, the number of aged people in Japan has increased, and for some other reasons, there has risen the problem of people who take care of the bedridden patients in daily life. And it is.expected that this kind of probkem would be more serious in the future. As one solution to the this problem, we've developed some manipulator systems which aid the nursing of bedridden patients. But the traditional manipulator is not powerful enough to be used in practice.In order to overcome this disadvantage in power, we developed a new type manipulator which is more powerful than the traditional one, by using the wire-driving mechanism. This mechanism has been thought to be useless, because the length of wire changes as the load changes, and it is difficult to know the precise position of the end effector. This time, we have solved this problem by putting high resolution encoders at each joint and sensing the displacement of the joints directly. As the result, we succeeded in developing a new type manipulator more powerful than the traditional one. And for controllability, we took the dual-PID control algorithm and improved the controlling characteristic., THE SOCIETY OF LIFE SUPPORT ENGINEERING
エル・エス・ティ学会誌, May 1989

帯磁コンタクトレンズを用いた無拘束眼球運動計測システムの開発
鎮西清行; 土肥健純; 増澤 徹, Nystagmus measurement is quite useful and popular for equilibrium function test. To measure it, several kinds of methods. for example, Electro-Nystagmography(ENG, orEOG) are developed and clinically used. But they have some problems. To solve those problems, such as the drift or noise on the output signal, or the improper restriction of the free movement of the subject's body and eyeball, we propose the following new measuring method. We adopted the magnetic measuring method, and constructed a prototype system. In this system, a set of magnetic sensors detects magnetic flux density of the magnetic contact lens. worn on the eyeball of the subject And using this system, we confirm the availability of this system., THE SOCIETY OF LIFE SUPPORT ENGINEERING
エル・エス・ティ学会誌, May 1989

Development of Fuzzy Blood Pressure Control System
Yasuhiro Fukui; Toru Masuzawa, y blood pressure control system has been developed to regulated blood pressure by using vaso-active drugs, which aims the medical treatment of the patient. Fuzzy logic is used to convert heuristic control rules as a physician's knowledge into an automatic control strategy. Usually, a physician decides infusion rate based on referring ideal pressure trajectory during control. To emulate such a physician's heuristic control, the controller refer an ideal pressure trajectory, for example, from the normal level to the target level. One of Inputs to the controller is a difference between real pressure and ideal pressure, where another is a rate of its pressure difference. An output from the controller is the change in drug infusion rate. Both of inputs and output are transformed into fuzzy sets, whose membership functions are predefined. Twenty one physician's control rules are converted into fuzzy control rules. The fuzzy control procedure consists of three steps : (1) computing both input values and finding their appropriate membership values (grade), (2) finding applied rules and applying fuzzy composition to infer weighted output fuzzy sets, (3) inferring the change in drug infusion rate by taking the center of mass of the membership function of output. Nine animal experiments are performed to evaluate the developed system by using rats with vasopressor drug, Angiotensin II Blood pressure was elevated from normal pressure (around 100 mmHg) to 150 mmHg. Satisfactory blood pressure control was realized on eight experiments and effectiveness of the controller was confirmed. The fuzzy control approach is especially useful for the closed-loop control in the medical fields, because the knowledge of expert physician's treatment is directly contained and represented in the control strategy. The system is expected to be applicable to the clinical cases. © 1989, Japanese Society for Medical and Biological Engineering. All rights reserved.
Japanese Journal of Medical Electronics and Biological Engineering, 1989

The control system for physiological sytem-Optimal control of blood-presure by using vaso-active drug
増澤徹
精密工学会誌, 1989

マン・マシン・インターフェースを考慮した聴覚障害児童のための発声発語訓練装置の開発
楢原弘之; 土肥健純; 堀内孝; 増澤徹, In this report, a basic principle of designing on effective man-machine interface is given to construct a speech training system based upon the information theory. Although the speech training system has been developed by our group, its evaluation in a field-testing indicated a need for correction in this system. In order to keep trainee's attention, a program on the display has to be attractive. Concerning these problems the newly designed inexpensive training system is constructed using the home computer MSX 2 and the speech processing interface board. The signals are picked up by a microphone, and then pass through a low pass filter which cut-off frequency is controllable by the micro computer. The analogue signals are converted to digital ones by the A/D convertor. The signal processor (μPD 7720) is adopted to find the peaks of the power spectrum which is realized by the cascaded 4 signal processors arrangement. Using the MSX 2 graphic functions, the result of this analysis is presented to trainee. This system could be utilized in the first three stage of speech training; basic vocalization;intensity, duration, pitch; pronounciation of specific vowels and dipthongs., Japanese Society of Medical Instrumentation
医科器械学, 01 Aug. 1988

アウターロータ型5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
松田 健一; 寺山 昌幸; 近藤 良; 増澤 徹
日本機械学会論文集Ｃ編, 25 May 1911, [Reviewed]

Sensorless Control of 5-Degrees of Freedom Controlled Self-Bearing Motor for Pediatric Ventricular Assist Device
小橋優輝; 長真啓; 増澤徹; 北山文矢; 西中知博
日本AEM学会誌, 2024

革新的磁気浮上技術を用いた次世代型小児用補助人工心臓の研究開発
長真啓; 増澤徹; 北山文矢; 西中知博; 築谷朋典; 水野敏秀; 梅木昭秀; 巽英介
人工臓器(日本人工臓器学会), 2023

Implantable Pediatric Ventricular Assist Device with Compact Axial Gap Type Self-bearing Motor using Four Three-phase Inverters
長真啓; 増澤徹; 北山文矢
村田学術振興・教育財団研究助成等成果報告書(Web), 2023

磁気浮上型人工心臓　　　　　　　　　　　　　　　
増澤徹
日本AEM学会誌, 10 Sep. 2017, [Reviewed], [Invited]
Lead

人工心臓の磁気浮上方式の現在と将来　　　　　　　　　　　　　　　
増澤 徹
電気学会誌, Sep. 2015, [Invited]
Lead

補助人工心臓とベアリング技術　　　　　　　　　　　　　　　
増澤徹
ベアリング新聞, 05 Jun. 2015, [Invited]

退院できる補助人工心臓　　　　　　　　　　　　　　　
増澤徹
日本機械学会誌, Feb. 2015, [Invited]

ゼロパワー制御を用いた磁気浮上全人工心臓の流量バランス制御　　　　　　　　　　　　　　　
山田悠; 増澤徹; ティムズダニエル
電気学会研究会資料 リニアドライブ研究会 LD-13-083〜103, 07 Oct. 2013

生体組織融着技術を用いた血管吻合装置の開発－加圧バンドを用いた場合の融着強度評価－
橋本一生; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
電気学会研究会資料 リニアドライブ研究会 LD-13-083〜103, 07 Oct. 2013, [Reviewed]

2C05 Nano-vibration device with flexure hinge structure to stimulate the sensory organ
HATTORI Keisuke; MASUZAWA Toru; KIMURA Takayuki; FURUYAMA Akira
The Proceedings of the Bioengineering Conference Annual Meeting of BED/JSME, 2013

生体組織融着技術を用いたステントの位置ずれ防止-小型コイルによるステントの誘導加熱と引張強度評価-
田代翔子; 橋本一生; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
日本機械学会関東支部・精密工学会・茨城大学茨城講演会講演論文集, 2013

Development and Practice of the Education Curriculum for the Department of Mechanical Engineering in Ibaraki University
堀辺忠志; 増澤徹; 関東康祐; 金野満; 黒崎利榮; 河合彰
J.ofJSEE, 2013

802 Total Artificial Heart with a single magnetically levitated motor
Sakata Yusuke; Masuzawa Toru; Nishimura Nobuhiko; Timms Daniel L
茨城講演会講演論文集 : Ibaraki district conference, 24 Aug. 2012

806 Development of small and high-performance outer-rotor-type 5-DOF self-bearing motor
Hirane Tatsuya; Matsuda Kenichi; Kondo Ryo; Masuzawa Toru
茨城講演会講演論文集 : Ibaraki district conference, 24 Aug. 2012

A radial type self-bearing motor for small maglev regenerative blood pump　　　　　　　　　　　　　　　
Keigo Ukita; Toru Masuzawa; Hiroyuki Onuma; Takashi Nishimura; Shunei Kyo
Proceedings of the 20th MAGDA Conference in Pacific Asia, 14 Nov. 2011

139 Study of Permanent Magnet Arrangement for IPM Type 5-DOF Self-bearing Motor
MATSUDA Kenichi; KONDO Ryou; MASUZAWA Toru; TERAYAMA Masayuki
Dynamics and Design Conference : D & D, 04 Sep. 2011

407 Study on IPM type 5-DOF self bearing motor
Sato Shinpei; Matsuda Kenichi; Kondo Ryo; Masuzawa Toru
茨城講演会講演論文集 : Ibaraki district conference, 26 Aug. 2011

EVALUATION OF THE MAGLEV MOTOR AND DESIGN OF THE CENTRIFUGAL BLOOD PUMP FOR PEDIATRIC ARTIFICIAL HEART
M. Osa; T. Masuzawa; E. Tatsumi
INTERNATIONAL JOURNAL OF ARTIFICIAL ORGANS, Aug. 2011

Surface characteristics and bonding of medical polymeric material
Nakamura N; Nam K; Kimura T; Masuzawa T; Okada T; Kishida A
Annual reports of the Institute of Biomaterials and Bioengineering, 2011

Surface characteristics and bonding of medical polymeric material
Nakamura N; Nam K; Kimura T; Masuzawa T; Okada T; Kishida A
Annual Report of the Institute of Biomaterials and Bioengineering, 2011

732 Development of an outer-rotor-type 5-DOF self-bearing motor
MATSUDA Ken-ichi; TERAYAMA Masayuki; KONDO Ryou; MASUZAWA Toru
Dynamics & Design Conference, 14 Sep. 2010

人工心臓開発の要素技術の現状と展望磁気浮上技術
増澤徹
第38回人工心臓と補助循環懇話会, 2010, 2010

Journal of Artificial Organs 2009:the year in review
Sawa Y; Tatsumi E; Funakubo A; Horiuchi T; Iwasaki K; Kishida A; Masuzawa T; Matsuda K; Nishimura M; Nishimura T; Tomizawa Y; Yamaoka T; Watanabe H
J Artif Organs, 2010

医用アクチュエーション技術の体系化に関する協同研究委員会活動報告　　　　　　　　　　　　　　　
増澤徹; 福長一義; 小沼弘幸; 住倉博仁
平成21年電気学会産業部門応用部門大会, 31 Aug. 2009

1008 Downsizing of a 5-DOF self-bearing motor for application of artificial heart
Terayama Masayuki; Matsuda Ken-ichi; Kondo Ryo; Masuzawa Toru
茨城講演会講演論文集 : Ibaraki district conference, 25 Aug. 2009

165 Development of Cell Culture Microdevice Actuated by Piezoelectric Thin Film for On-Chip Regulation of Cell Functions
MATSUZAWA Yuuta; SHIBATA Takayuki; KAWASHIMA Takahiro; MASUZAWA Toru; KISHIDA Akio
東海支部総会講演会講演論文集, 01 Mar. 2009

138 Impeller movement and hydraulic force changes in a magnetically suspended artificial heart
ONUMA Hiroyuki; MASUZAWA Toru
バイオエンジニアリング講演会講演論文集, 22 Jan. 2009

Journal of Artificial Organs 2008:the year in review
Sawa Y; Tatsumi E; Funakubo A; Horiuchi T; Iwasaki K; Kishida A; Masuzawa T; Matsuda K; Nishimura M; Nishimura T; Tomizawa Y; Yamaoka T; Watanabe H
J Artif Organs, 2009

医用アクチュエーション技術の現状
医用アクチュエーション技術に関する共同研究委員会編
電気学会技術報告第1122号, Jul. 2008

257 Development of Biodevice Actuated by Piezoelectric Thin Film for On-chip Regulation of Cell Functions
WAKISAKA Kenji; MATSUZAWA Yuuta; SHIBATA Takayuki; KAWASHIMA Takahiro; MASUZAWA Toru; KISHIDA Akio
東海支部総会講演会講演論文集, 01 Mar. 2008

扁平型ハイブリッド磁気軸受の最適化設計　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 鈴木健一
第20回「電磁力関連のダイナミクス」シンポジウム講演論文集, 2008

Journal of Artificial Organs 2007:the year in review
Sawa Y; Tatsumi E; Funakubo A; Horiuchi T; Iwasaki K; Kishida A; Masuzawa T; Matsuda K; Nishimura M; Nishimura T; Tomizawa Y; Yamaoka T; Watanabe H
J Artif Organs, 2008

扁平型ハイブリッド磁気軸受の開発　　　　　　　　　　　　　　　
鈴木健一; 増澤徹
第16回MAGDAコンファレンスin京都講演論文集, 22 Nov. 2007

５軸能動制御型セルフベアリングモータの開発　　　　　　　　　　　　　　　
松田健一; 石川達也; 増澤徹; 近藤良
第16回MAGDAコンファレンスin京都講演論文集, 22 Nov. 2007

磁気軸受用センサの開発　　　　　　　　　　　　　　　
岡田養二; 石川達也; 増澤徹; 近藤良
第16回MAGDAコンファレンスin京都講演論文集, 22 Nov. 2007

人工心臓のための小型ハイブリッド型磁気軸受　　　　　　　　　　　　　　　
増澤徹; 鈴木健一; 黒須寛秋; 加藤綾子
電気学会研究会資料LD-07-32～49, 26 Oct. 2007

207 Magnetically suspended blood pump with double biased magnetic flux
Sasaki Eisuke; Masuzaswa Toru; Onuma Hiroyuki
茨城講演会講演論文集 : Ibaraki district conference, 28 Sep. 2007

Magnetic suspension system in medical actuation technology　　　　　　　　　　　　　　　
Toru Masuzawa
平成19年度電気学会産業応用部門講演論文集, 21 Aug. 2007

人工心臓の最近の進歩　　　　　　　　　　　　　　　
増澤徹
体外循環と補助循環2007第23回教育セミナー（日本人工臓器学会）, 10 Jul. 2007, [Invited]

人工心臓用ダブルバイアス磁束型磁気浮上システム　　　　　　　　　　　　　　　
増澤徹; 加藤裕介; 佐々木瑛祐; 小沼弘幸
第19回電磁力関連のダイナミクスシンポジウム講演論文集, May 2007

茨城大学工学部における“ものづくり”創造教育の取り組み
伊藤伸英; 篠塚 淳; 前川克廣; 増澤 徹; 伊藤吾朗; 金野 満; 柴田隆行
工学教育, 2007

Journal of Artificial Organs 2006:the year in review
Sawa Y; Horiuchi T; Kishida A; Masuzawa T; Nishimura M; Tatsumi E; Tomizawa Y; Watanabe H
J Artif Organs, 2007

Active mask UV lithography systme for MEMS and μTAS applications
Terutake Hayashi; Takayuki Shibata; Takahiro Kawashima; Eiji Makino; Takashi Mineta; Toru Masuzawa
Proceedings of the 21st Annual ASPE Meeting, ASPE 2006, 01 Dec. 2006

A magnetically levitated artificial heart with a flux guided hybrid magnetic bearing
KATO Y.; MASUZAWA T.
電気学会研究会資料. LD, リニアドライブ研究会, 26 Oct. 2006

203 Optimal design of the magnetic bearing for artificial hearts
NAKAYAMA N.; MASUZAWA T.; KATOH A.; SUZUKI S.
茨城講演会講演論文集 : Ibaraki district conference, 14 Sep. 2006

204 Magnetically levitated artificial heart with bias magnet flux guided bearing
KATO Y.; MASUZAWA T.
茨城講演会講演論文集 : Ibaraki district conference, 14 Sep. 2006

Optimized Design for a Hybrid Magnetic Bearing for the Artificial Heart
Katoh A; Masuzawa T
Proceedings for the Tenth International Symposium on Magnetic Bearings: CD-ROM, Aug. 2006

Journal of Artificial Organs 2005:the year in review
Sawa Y; Horiuchi T; Kishida A; Masuzawa T; Mizuguchi K; Nishimura M; Okoshi T; Shinzato T; Tatsumi E; Tomizawa Y; Watanabe H
J Artif Organs, 2006

人工心臓（基礎）　　　　　　　　　　　　　　　
増澤徹
人工臓器, 2006

Current Development Status of Electric Driven Artificial Heart
MASUZAWA Toru; Toru MASUZAWA
Journal of the Japan Society of Applied Electromagnetics and Mechanics, 10 Sep. 2005

703 Miniaturization of the axial type magnetically levitated centrifugal pump for artificial heart
KATO Y.; MASUZAWA T.
茨城講演会講演論文集 : Ibaraki district conference, 08 Sep. 2005

10311 Development of the magnetically levitated centrifugal pump with three-DOF control for artificial heart
KATO Y.; MURAKAMI M.; ONUMA H.; MASUZAWA T.
日本機械学会関東支部総会講演会講演論文集, 17 Mar. 2005

Development of Bio-Microdevice Actuated by Piezoelectric Thin Film for Cell Culture
MAKITA Yoshiyuki; SHIBATA Takayuki; MASUZAWA Toru; KISHIDA Akio; MAKINO Eiji
茨城講演会講演論文集 : Ibaraki district conference, 23 Sep. 2004

Accelerating system of cell multiplication with nanometer vibration
KUSAMA Jun; ISHIMARU Masato; MASUZAWA Toru; KIMURA Takayuki; SHIBATA Takayuki; KISHIDA Akio
茨城講演会講演論文集 : Ibaraki district conference, 23 Sep. 2004

医療機器の今後10年間の展望，人工臓器－人工心臓を中心に－
増澤徹
医科器械学, Jun. 2004

Magnetically levitated artificial heart with an axially suspended motor
ONUMA Hiroyuki; MASUZAWA Toru
バイオエンジニアリング講演会講演論文集, 21 Jan. 2004

Nakamura M, Homma A, Tatsumi E, Uesho K, Taenaka Y, Masuzawa T. Transient response of remnant atrial heart rate to step changes in total artificiala heart output.
M. Nakamura; A. Homma; E. Tatsumi; K. Uesho; Y. Taenaka; T. Masuzawa
J Artif Organs, 2002

Oxygen-demand-based physiological control of the total artificial heart.
M. Nakamura; S. Takatani; K. Ohuchi; T. Sakamoto; A. Homma; E. Tatsumi; K. Uesho; Y. Taenaka; T. Masuzawa
Journal of Congestive Heart Failure and Circulatory Support, 2001

Long-term in vivo testing of the National Cardiovascular Center electrohydraulic total artificial heart.
E. Tatsumi; Y. Taenaka; K. Uesho; A. Homma; T. Nishinaka; Y. Kakuta; T. Tsukiya; N. Katagiri; K. Shioya; M. Takahashi; H. Ohnishi; K. Sato; H. Takano; T. Masuzawa; M. Nakamura; K. Tsukahara; K. Tsuchimoto
Journal of Congestive Heart Failure and Circulatory Support, 2001

Mixed venous oxygen saturation as a promising parameter for physiologic control of total artificial heart
M Nakamura; A Homma; E Tatsumi; K Uesho; Y Taenaka; T Masuzawa; T Nakamura; B Zhang; Y Kakuta; K Imada; T Nakatani; H Takano
ASAIO JOURNAL, Nov. 2000

In vivo long-term evaluation of the national cardiovascular center electrohydraulic total artificial heart system
E. Tatsumi; Y. Taenaka; K. Uesho; A. Homma; T. Nishinaka; Y. Kakuta; T. Tsukiya; N. Katagiri; K. Imada; M. Takahashi; Y. Ohnishi; K. Sato; H. Takano; T. Masuzawa; M. Nakamura
ASAIO Journal, 2000

Practical Evaluation Of A Transcutaneous Energy Transmission System For The Totally Implantable Artificial Heart By A Chronic Animal Experiment." jointly authored"
Y Kakuta; Y Tenaka; E Tatsumi; K Uesho; M Nakamura; T Masuzawa; K Shiba; K Kosiji
The Japanese Journal of Artificial Organs, 2000

In vivo long term evaluation of transcutaneous energy transmission for tatally implantable artifitial heart
Y. Kakuta; E. Tatsumi; Y. Taenaka; K. Uesho; A. Homma; M. Nakamura; T. Masuzawa; K. Shiba; K. Koshiji
ASAIO Journal, 2000

903 Radial type magnetically suspended centrifugal blood pump for artificial heart
ONUMA Hiroyuki; MASUZAWA Toru; OKADA Yohji
茨城講演会講演論文集日立 2000, 2000

Current status of development and in vivo evaluation of the National Cardiovascular Center electrohydraulic total artificial heart system
Eisuke Tatsumi; Yoshiyuki Taenaka; Kunihiro Uesho; Akihiko Homma; Tomohiro Nishinaka; Yukihide Kakuta; Tomonori Tsukiya; Hisateru Takano; Toru Masuzawa; Makoto Nakamura; Kohji Koshiji; Yasuhiro Fukui; Kinji Tsukahara; Katsuya Tsuchimoto; Hideki Wakui
Journal of Artificial Organs, 2000

Effects of long-term nonpulsatile left heart bypass on the mechanical properties of the aortic wall
T Nishimura; E Tatsumi; Y Taenaka; T Nishinaka; T Nakatani; T Masuzawa; M Nakata; M Nakamura; S Endo; H Takano
ASAIO JOURNAL, Sep. 1999

Technology to Develop the Implantable Artificial Heart System
MASUZAWA T.
The Japanese journal of medical instrumentation, 01 Jul. 1999

Development of a Novel Integrated Artificial Heart-Lung Device.
巽英介; 武輪能明; 妙中義之; 中谷武嗣; 増沢徹; 高野久輝
バイオエンジニアリング講演会講演論文集, 1998

Development and control of an internally embedded entirely artificial electrohydraulic heart.
増沢徹; 中村真人; 巽英介; 妙中義之; 高野久輝; 大野孝; 福井康裕; 土本健也; 塚原金二
精密工学会大会学術講演会講演論文集, 1998

人工心臓(1)
廣瀬 一; 梅津 光生; RANAWAKE Manoja; 飯沼 一成; 中田 紀彦; 藤本 哲男; 野尻 知里; 富岡 淳; 竹本 尚史; 平松 浩; 北野 智哉; 林 洋次; 森 敏夫; 小林 賢; 山崎 健二; 小柳 仁; 遠藤 誠子; 増澤 徹; 瀧浦 晃基; 巽 英介; 妙中 義之; 中谷 武嗣; 大野 孝; 西村 隆; 武輔 能明; 孫 領相; 中村 真人; 高野 久輝; 山口 高広; 大竹 重彰; 澤 芳樹; 福嶌 教偉; 西村 元延; 張 〓嶂; 鍵崎 康治; 大畑 俊裕; 竹谷 哲; 松田 暉; 八田 光弘; 古川 博史; 木原 信一郎; 斎藤 聡; 星 浩信; 野々山 真樹; 北村 昌也
人工臓器, 1997

Development of an Integrated Heart-Lung Support System for Emergent Use.
巽英介; 武輪能明; 妙中義之; 中谷武嗣; 増沢徹; 中田雅子; 西村隆; 中村真人; 遠藤誠子
ライフサポート学会大会講演予稿集, 1997

Molphological changes of aortic wall due to long-term high-flow nonpulsatile left heart bypass.
西村隆; 巽英介; 妙中義之; 脇坂佳成; 中谷武嗣; 増沢徹; 武輪能明; 高野久輝; 高市成子
人工臓器(日本人工臓器学会), 1997

Evaluation of a centrifugal blood pump for long-term circulatory support for up to one year.
脇坂佳成; 妙中義之; 近成賢一; 中谷武嗣; 巽英介; 増沢徹; 西村隆; 武輪能明; 高野久輝
人工臓器(日本人工臓器学会), 1997

Improvement of efficiency and reliability for externally-coupled transcutaneous energy transmission system
Shiba K; Miyasaka K; Koshiji K; Shu E; Utsunomiya T; Tsukahara K; Tsuchimoto K; Ohu-mi T; Ohno T; Masuzawa T; Tatsumi E; Taenaka Y; Takano H
Proceedings of the Society Conference of IEICE, 18 Sep. 1996

Importance of metabolic function of the natural lung evaluated by prolonged exclusion of the pulmonary circulation
Kazuhiro Eya; Eisuke Tatsumi; Yoshiyuki Taenaka; Yoshiaki Takewa; Koichi Toda; Yoshinari Wakisaka; Takeshi Nakatani; Toru Masuzawa; Yuzo Baba; Koji Miyazaki; Takashi Nishimura; Takashi Ohno; Jae Mok Ahn; Haruhiko Akagi; Hisateru Takano
ASAIO Journal, 1996

Long-term cardiopulmonary support with a composite artificial heart-lung system
E TATSUMI; K EYA; Y TAENAKA; T NAKATANI; Y BABA; T MASUZAWA; Y WAKISAKA; K TODA; K MIYAZAKI; H TAKANO
ASAIO JOURNAL, Jul. 1995

磁気浮上技術の原理と応用　　　　　　　　　　　　　　　
Contributor
科学情報出版株式会社, 26 Mar. 2018
9784904774656

Mechanical Circulatory and Respiratory Support　　　　　　　　　　　　　　　
Edited by Gregory; Stevens & Fraser, Joint work
Elsevier, Academic Press, 04 Oct. 2017
9780128104910

南山堂医学大辞典 第20版　　　　　　　　　　　　　　　
Joint work
南山堂, 01 Apr. 2015

増補新訂版 人工臓器は，いま　　　　　　　　　　　　　　　
Joint work
はる書房, 25 Dec. 2012

ひとの暮らしと表面科学（現代表面科学シリーズ５）　　　　　　　　　　　　　　　
日本表面科学会編集, Joint work
共立出版株式会社, 25 Jul. 2011
9784320033702

Advanced Bio/Medical Devices and Equipments for Health Care　　　　　　　　　　　　　　　
Supervisor: Kohji Mitsubayashi, Joint work
CMC books, 29 May 2009
9784781301204

人工臓器イラストレテッド　　　　　　　　　　　　　　　
日本人工臓器学会編集, Joint work
はる書房, 05 Nov. 2007
9784899840800

人工臓器は，いま　　　　　　　　　　　　　　　
日本人工臓器学会編集, Joint work
はる書房, 07 Nov. 2003
4899840454

Clinical application of Computational Mechanics to the Cardiovascular System, T. Yamaguchi(Ed.)　　　　　　　　　　　　　　　
Joint work
Springer, 2000

ＭＥ用語辞典　　　　　　　　　　　　　　　
日本エム・イー学会編, Joint work
コロナ社, Sep. 1999

人工心臓のためのハイブリッドMR流体変速機の研究
小川夏輝; 北山文矢; 増澤徹; 佐藤樹; 長真啓
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20240306, 20240307

体内植込み型小児用補助人工心臓のための小型・扁平磁気浮上モータの研究　　　　　　　　　　　　　　　
河村幹也; 長真啓; 北山文矢; 増澤徹; 西中知博
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20240306, 20240307

アキシャル型全人工心臓用磁気浮上モータの改良
江藤絢平; 増澤徹; 今野美紗紀; 桑本真子; 北山文矢; 長真啓
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20240306, 20240307

ホモポーラ型磁気浮上モータを用いた全置換型人工心臓の研究
鈴木修太; 増澤徹; 長真啓; 北山文矢; 信太宗也
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20240306, 20240307

磁気浮上血液ポンプにおけるスクイーズ効果の検討　　　　　　　　　　　　　　　
谷平健心; 増澤徹; 後藤結帆; 長真啓; 北山文矢
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20240306, 20240307

ホモポーラ型磁気浮上モータを用いた全置換型人工心臓の制御システムの構築　　　　　　　　　　　　　　　
平口航士朗; 増澤徹; 佐藤光志朗; 鈴木修太; 長真啓; 北山文矢
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20240306, 20240307

５軸制御セルフベアリングモータの三相駆動・制御システムの開発　　　　　　　　　　　　　　　
村山優心; 長真啓; 長澤優樹; 北山文矢; 増澤徹
第33回ライフサポート学会フロンティア講演会, 06 Mar. 2024
20200306, 20240307

磁気浮上式血液ポンプにおける粘性流体送液時のインペラ支持性能　　　　　　　　　　　　　　　
長真啓; 増澤徹; 北山文矢; 西中知博; 築谷朋典; 巽英介
第32回MAGDAコンファレンスin 金沢, 27 Nov. 2023
20231127, 20231128

ホモポーラ型磁気浮上モータを用いた全置換型人工心臓
鈴木修太; 増澤徹; 長真啓; 信太宗也; 北山文矢
第32回MAGDAコンファレンスin 金沢, 27 Nov. 2023
20231127, 20231128

人工心臓のためのハイブリッドMR流体変速機
佐藤樹; 増澤徹; 北山文矢; 長真啓
第32回MAGDAコンファレンスin 金沢, 27 Nov. 2023
20231127, 20231128

小児用補助人工心臓用磁気浮上モータのセンサレス制御化　　　　　　　　　　　　　　　
小橋優輝; 長真啓; 増澤徹; 北山文矢; 西中知博
第32回MAGDAコンファレンスin 金沢, 27 Nov. 2023
20231127, 20231128

Pediatric ventricular assist device and artificial hearts with magnetic levitation mechanism　　　　　　　　　　　　　　　
Toru Masuzawa
11th Asan Medical Center Biomedical Engineering Center Symposium, 16 Nov. 2023
20231116, 20231116

Magnetic bearing of maglev total artificial heart　　　　　　　　　　　　　　　
Toru MASUZAWA; Misaki KONNO; Mako KUWAMOTO; Masahiro OSA; Fumiya KITAYAMA
21st International Symposium on Applied Electromagnetics and Mechanics, 14 Nov. 2023
20231112, 20231115

NPOオーファンデバイス研究開発の設立　　　　　　　　　　　　　　　
増澤徹; 小野稔; 松宮護郎; 岸田晶夫
第61回日本人工臓器学会大会, 11 Nov. 2023
20231109, 20231111

Magnetic Levitation Technology for MCS　　　　　　　　　　　　　　　
TORU MASUZAWA
The 29th annual meeting of The International Society for Mechanical Circulatory Support, 30 Oct. 2023, [Invited]
20231030, 20231101

Magnetic levitation technology for artificial heart　　　　　　　　　　　　　　　
Toru Masuzawa
APSAO 2023 Conference, 25 Sep. 2023, [Invited]
20230925, 20230926

完全置換型磁気浮上人工心臓の流量バランス制御機能向上のための研究
桑本真子; 増澤徹; 長真啓; 信太宗也; Daniel L Timms
Life2023, 19 Sep. 2023
20230919, 20230921

小児用磁気浮上型補助人工心臓の粘性液体下におけるポンプ性能とインペラ支持性能評価　　　　　　　　　　　　　　　
佐藤遼一郎; 長真啓; 増澤徹; 北山文矢
第31回茨城講演会, 18 Aug. 2023
20230818, 20230818

分割巻線を用いた磁気浮上小児用補助人工心臓の性能評価　　　　　　　　　　　　　　　
長澤優樹; 長真啓; 北山文矢; 増澤徹
第31回茨城講演会, 18 Aug. 2023
20230818, 20230818

チタン合金壁通過型渦電流変位センサの特性評価　　　　　　　　　　　　　　　
菅原槙人; 増澤徹; 長真啓; 北山文矢; 柴健次
第31回茨城講演会, 18 Aug. 2023
20230818, 20230818

ラジアル型全人工心臓用磁気浮上モータの改良　　　　　　　　　　　　　　　
佐藤光志朗; 増澤徹; 鈴木修太; 長真啓; 北山文矢
第31回茨城講演会, 18 Aug. 2023
20230818, 20230818

体内植込型全人工心臓のためのホモポーラ型磁気浮上モータ　　　　　　　　　　　　　　　
鈴木修太; 増澤徹; 川口哲平; 長真啓; 北山文矢
第35回「電磁力関連のダイナミクス」シンポジウム, 12 Jun. 2023
20230612, 20230614

出力シャフトに永久磁石を配置した人工心臓用MR変速機　　　　　　　　　　　　　　　
北山文矢; 増澤徹; 佐藤樹; 長真啓
第３５回「電磁力関連のダイナミクス」シンポジウム, 12 Jun. 2023
20230612, 20230614

体内埋め込みを目指した磁気浮上型小児用人工心臓の駆動システムの研究開発　　　　　　　　　　　　　　　
長澤優樹; 長真啓; 北山文矢; 増澤徹
第32回ライフサポート学会フロンティア講演会, 13 Mar. 2023
20230313, 20230314

ホモポーラ型磁気軸受を用いたラジアル型磁気浮上全人工心臓の研究　　　　　　　　　　　　　　　
佐藤光志朗; 増澤徹; 長真啓; 北山文矢
第32回ライフサポート学会フロンティア講演会, 13 Mar. 2023
20230313, 20230314

人工心臓のためのハイブリッド型MR流体変速機の研究　　　　　　　　　　　　　　　
佐藤樹; 増澤徹; 北山文矢; 長真啓
第32回ライフサポート学会フロンティア講演会, 13 Mar. 2023
20230313, 20230314

低損失・高い磁気支持性能を有する小児用補助人工心臓用磁気浮上モータの研究　　　　　　　　　　　　　　　
佐藤遼一郎; 長真啓; 北山文矢; 増澤徹
第32回ライフサポート学会フロンティア講演会, 13 Mar. 2023
20230313, 20230314

磁気浮上補助人工心臓のための小型制御システムの開発　　　　　　　　　　　　　　　
齋藤広明; 増澤徹; 長真啓; 北山文矢
第32回ライフサポート学会フロンティア講演会, 13 Mar. 2023
20230313, 20230314

磁気浮上技術と人工心臓　　　　　　　　　　　　　　　
増澤徹
第32回ライフサポート学会フロンティア講演会, 13 Mar. 2023, [Invited]
20230313, 20230314

Magnetic Suspension Stability of a Compact Axial Flux Self-Bearing Motor for Implantable Pediatric Rotary Blood Pumps　　　　　　　　　　　　　　　
Osa Masahiro; Toru Masuzawa
18th International Symposium on Magnetic Bearings, 19 Feb. 2023
20230218, 20230221

小児用補助人工心臓のための磁気浮上型遠心ポンプの性能評価　　　　　　　　　　　　　　　
長真啓; 増澤徹; 西中知博; 築谷朋典; 水野敏秀; 梅木昭秀; 巽英介
第51回人工心臓と補助循環懇話会学術集会, 17 Feb. 2023
20230217, 20230218

小児用補助人工心臓用5軸制御セルフベアリングモータの駆動系簡素化の検討　　　　　　　　　　　　　　　
長真啓; 増澤徹; 北山文矢; 西中知博; 巽英介
第31回MAGDAコンファレンス, 01 Nov. 2022
20221101, 20221102

磁気浮上人工心臓のための制御周波数の検討　　　　　　　　　　　　　　　
齋藤広明; 増澤徹; 長真啓; 北山文也
第31回MAGDAコンファレンス, 01 Nov. 2022
20221101, 20221102

Magnetically levitated mechanical circulatory support systems　　　　　　　　　　　　　　　
T. Masuzawa; M. Osa; T. Nishinaka; D. Timms
the 48th Annual Congress of the European Society for Artificial Organs, 10 Sep. 2022
20220906, 20220910

小児用補助人工心臓用磁気浮上モータの外径拡大による高支持力・高トルク化の検討　　　　　　　　　　　　　　　
小橋優輝; 長真啓; 増澤徹; 西中智博
第30回茨城講演会, 19 Aug. 2022
20220819, 20220819

両心室シャント構造を持つ完全置換型磁気浮上人工心臓のポンプ性能　　　　　　　　　　　　　　　
桑本真子; 増澤徹; 長真啓; 信太宗也; Daniel L Timms
第30回茨城講演会, 19 Aug. 2022
20220819, 20220819

体内埋込み型磁気浮上式小児用補助人工心臓の動物実験に向けた改良　　　　　　　　　　　　　　　
長真啓; 増澤徹; 西中知博; 築谷朋典; 巽英介
第34回「電磁力関連のダイナミクス」シンポジウム, 11 May 2022
20220511, 20220513

磁気浮上人工心臓における制御周波数と浮上安定性の関係　　　　　　　　　　　　　　　
齋藤広明; 増澤徹; 長真啓
第34回「電磁力関連のダイナミクス」シンポジウム, 11 May 2022
20220511, 20220513

小児用補助人工心臓用磁気浮上モータの省エネルギー化と支持性能の向上　　　　　　　　　　　　　　　
小橋優輝; 増澤徹; 長真啓
第31回ライフサポート学会フロンティア講演会, 07 Mar. 2022
20220307, 20220308

複合低エネルギーを用いた自己接合型脱血管の実用化に向けた検討　　　　　　　　　　　　　　　
鈴木修太,増澤徹,長真啓,西中智博
第31回ライフサポート学会フロンティア講演会, 07 Mar. 2022
20220307, 20220308

磁気浮上型小児用補助人工心臓の高度化に関する研究　　　　　　　　　　　　　　　
山下俊大; 増澤徹; 長真啓; 巽英介; 西中智博
第31回ライフサポート学会フロンティア講演会, 07 Mar. 2022
20220307, 20220308

ホモポーラ磁気軸受を用いた人工心臓磁気浮上モータの研究開発　　　　　　　　　　　　　　　
川口哲平; 増澤徹; 長真啓
第31回ライフサポート学会フロンティア講演会, 07 Mar. 2022
20220307, 20220308

テンセグリティ細胞模擬ロボットのソレノイドアクチュエータの検討　　　　　　　　　　　　　　　
桑本真子,増澤徹,長真啓
第31回ライフサポート学会フロンティア講演会, 07 Mar. 2022
20220307, 20220308

小児用補助人工心臓用磁気浮上モータの異なる制御軸数における磁気支持性能と電力特性の評価　　　　　　　　　　　　　　　
山下俊大; 増澤徹; 長真啓; 巽英介; 西中知博
第30回MAGDAコンファレンス, 06 Dec. 2021
20211206, 20211206

改良型遠心ポンプの改善点報告と実機評価，小型遠心血液ポンプを用いた磁気浮上型小児用補助人工心臓の研究開発　　　　　　　　　　　　　　　
長真啓; 山下俊大; 増澤徹; 西中知博; 築谷朋典; 水野敏秀; 片桐伸将; 巽英介; 柳園宣紀; 一ノ瀬高紀
日本定常流ポンプ研究会学術集会202, 27 Nov. 2021
20211127, 20211127

乳幼児用体内埋込み型補助人工心臓開発に向けた数値流体解析による磁気浮上式遠心血液ポンプ設計の検討　　　　　　　　　　　　　　　
信太宗也,増澤徹,築谷朋典,長真啓,西中知博,巽英介
第59回日本人工臓器学会大会, 26 Nov. 2021
20211125, 20211127

超小型な磁気浮上モータを用いた小児用人工心臓の性能評価　　　　　　　　　　　　　　　
長真啓; 山下俊大; 増澤徹; 西中知博; 築谷朋典; 水野敏秀; 片桐伸将; 巽英介; 柳園宜紀; 一ノ瀬高紀
第59回日本人工臓器学会大会, 26 Nov. 2021
20211125, 20211127

埋め込み型補助人工心臓のための緊急エネルギ維持機構　　　　　　　　　　　　　　　
LIFE2020-2021, 16 Sep. 2021
20210916, 20210918

模擬循環回路による補助循環下の冠循環流量評価　　　　　　　　　　　　　　　
LIFE2020-202, 16 Sep. 2021
20210916, 20210918

完全置換型磁気浮上人工心臓のポンプ特性　　　　　　　　　　　　　　　
對馬謙一; 増澤徹; 長真啓; 信太宗也; Timms Daniel
LIFE2020-202, 16 Sep. 2021
20210916, 20210918

小児用人工心臓用アキシャル型セルフベアリングモータの動特性評価　　　　　　　　　　　　　　　
長真啓,増澤徹,築谷朋典,西中知博,巽英介
Dynamics and Design Conference 2021, 16 Sep. 2021
20210916, 20210916

Dynamic Suspension Performance of an Ultra-Compact 5-DOF Controlled Axial Gap Type Self-Bearing Motor for Use in Pediatric Ventricular Assist Device　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Toshihiro Yamashita; Eisuke Tatsumi
The 17th International Syimposium on Magnetic Bearings, 20 Aug. 2021
20210820, 20210820

小児用人工心臓用磁気浮上モータの小型化に関する研究　　　　　　　　　　　　　　　
第33回「電磁力関連のダイナミクス」シンポジウム, 19 May 2021
20210519, 20210521

体内植込型補助人工心臓のためのホモポーラ型磁気浮上モータ　　　　　　　　　　　　　　　
川口哲平,増澤徹,長真啓
第33回「電磁力関連のダイナミクス」シンポジウム, 19 May 2021
20210519, 20210521

人工心臓のためのホモポーラ型磁気軸受の支持力向上の検討　　　　　　　　　　　　　　　
上田優人; 増澤徹; 長真啓; Megan Kavin
第31回「電磁力関連のダイナミクス」シンポジウム, 22 May 2019

全置換型磁気浮上人工心臓の右心ポンプ性能の向上に関する研究　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 信太宗也; 長真啓; Daniel L Timms
第28回ライフサポート学会フロンティア講演会, 15 Mar. 2019

小児用補助人工心臓用磁気浮上モータの省エネルギー化に関する研究　　　　　　　　　　　　　　　
山口清; 増澤徹; 長真啓; 織原涼雅; 巽英介
第28回ライフサポート学会フロンティア講演会, 15 Mar. 2019

埋込型人工心臓への使用を目的とした緊急時電力供給用小型フライホールの研究開発　　　　　　　　　　　　　　　
柳沼修太; 増澤徹; 長真啓; 柴建次; 巽英介; 西村隆
第28回ライフサポート学会フロンティア講演会, 15 Mar. 2019

冠動脈バイパス手術における血管接合支援デバイスの研究開発　　　　　　　　　　　　　　　
羽根田洋輔; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫; 巽英介
第28回ライフサポート学会フロンティア講演会, 15 Mar. 2019

冠動脈バイパス手術のための血管吻合デバイスの開発　　　　　　　　　　　　　　　
吉田尚記; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫; 巽英介
第28回ライフサポート学会フロンティア講演会, 15 Mar. 2019

血液Ht変化に伴う粘度変化が磁気浮上インペラ非制御位置計測による血液遠心ポンプ流量推定精度に及ぼす影響　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓
第47回人工心臓と補助循環懇話会学術集会, 01 Feb. 2019

超小型磁気浮上モータを用いた次世代型遠心連続流式小児用人工心臓の血液循環性能評価，　　　　　　　　　　　　　　　
長真啓; 増澤徹; 織原涼雅; 築谷朋典; 巽英介
第47回人工心臓と補助循環懇話会学術集会, 01 Feb. 2019

血液遠心ポンプ拍出流量推定手法確立のための磁気浮上インペラ流体評価　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓
第31回バイオエンジニアリング講演会, 14 Dec. 2018

磁気浮上インペラ偏心位置を用いた新しい血液遠心ポンプ流量推定手法確立のための流路内圧不平衡場解析　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓
日本生体医工学会関東支部若手研究者発表会2018, 01 Dec. 2018

小児心不全治療のための超小型な磁気浮上型補助人工心臓の研究開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 織原涼雅; 巽英介
第56回日本人工臓器学会大会, 01 Nov. 2018

高せん断流れ場におけるせん断応力と接液面の表面粗さが溶血に及ぼす影響　　　　　　　　　　　　　　　
安武勇貴; 長真啓; 丸山修; 西田正浩; 増澤徹
第56回日本人工臓器学会大会, 01 Nov. 2018

Dynamic movement of the magnetically levitated impeller during pulsatile operation　　　　　　　　　　　　　　　
Toru Masuzawa; Shuya Shida; Masahiro Osa; Takashi Nishimura; Eisuke Tatsumi
26th ISMCS2018, 31 Oct. 2018

Next generation Ultra-Compact centrifugal pediatric VAD using maglev motor with Improved design to enhance energy efficiency　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi
26th ISMCS2018, 31 Oct. 2018

Novel flow rate estimation method of a centrifugal blood pump using passive stabilization dynamics of magnetically levitated impeller　　　　　　　　　　　　　　　
Shuya Shida; Toru Masuzawa; Masahiro Osa
26th ISMCS2018, 31 Oct. 2018

Next generation Ultra-Compact centrifugal pediatric VAD using maglev motor with,Improved design to enhance energy efficiency　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi
26th ISMCS2018, 31 Oct. 2018

小児用人工心臓のための超小型磁気浮上モータの改良　　　　　　　　　　　　　　　
織原涼雅; 増澤徹; 長真啓; 巽英介
第27回MAGDAコンファレンス in Katusshika, 20 Oct. 2018

血液遠心ポンプ拍出流量推定のための磁気浮上インペラふれ回り運動解析　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓; 大野康平; 西村隆; 許俊鋭; 巽英介
LIFE2018, 06 Sep. 2018

複合低エネルギ冠動脈バイパス接合デバイスの開発　　　　　　　　　　　　　　　
羽根田洋輔; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫; 片桐伸将; 巽英介
LIFE2018, 06 Sep. 2018

磁気浮上式血液ポンプ内インペラ径方向受動安定ダイナミクスの血液量計測への応用　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓
第57回日本生体医工学会大会, 19 Jun. 2018

全置換型磁気浮上人工心臓の浮上インペラの非制御軸の振動抑制　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 長真啓; Daniel L Timms
第30回「電磁力関連のダイナミクス」シンポジウム, 23 May 2018

心拍同期型体外設置磁気浮上血液ポンプの研究開発　　　　　　　　　　　　　　　
佐藤遼太; 増澤徹; 長真啓; 西村隆; 許俊鋭; 巽英介
第27回ライフサポート学会フロンティア講演会, 09 Mar. 2018

全置換型磁気浮上人工心臓の径方向受動安定性の向上　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 長真啓; Daniel L Timms
第27回ライフサポート学会フロンティア講演会, 09 Mar. 2018

人工心臓のためのホモポーラ型磁気浮上モータの構造検討　　　　　　　　　　　　　　　
上田優人; 増澤徹; 長真啓; 小泉綾香
第27回ライフサポート学会フロンティア講演会, 09 Mar. 2018

高せん断流れ場における表面粗さと溶血に関する研究　　　　　　　　　　　　　　　
安武勇貴; 増澤徹; 長真啓; 丸山修
第27回ライフサポート学会フロンティア講演会, 09 Mar. 2018

これからのMCSデバイス開発　　　　　　　　　　　　　　　
増澤徹
第46回人工心臓と補助循環懇話会学術集会, 09 Feb. 2018

磁気浮上式血液ポンプ内インペラ受動安定位置計測による血流量推定　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓; 佐藤遼太
第46回人工心臓と補助循環懇話会学術集会, 09 Feb. 2018

インペラ変位による流体力増大を考慮した磁気浮上遠心血液ポンプ内ボリュート形状の検討　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓
第30回バイオエンジニアリング講演会, 14 Dec. 2017

全置換型磁気浮上人工心臓への反発型永久磁石磁気軸受の組み込み　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 國府田芳彰; 長真啓; Daniel L Timms
第26回MAGDAコンファレンス in 金沢, 26 Oct. 2017

人工心臓への適用を目的とした4軸制御型磁気軸受の開発　　　　　　　　　　　　　　　
小泉綾香; 増澤徹; 長真啓
第26回MAGDAコンファレンス in 金沢, 26 Oct. 2017

心拍同期型磁気浮上体外循環血液ポンプの径方向安定性評価　　　　　　　　　　　　　　　
佐藤遼太; 増澤徹; 長真啓; 大野康平; 西村隆; 許俊鋭
第26回MAGDAコンファレンス in 金沢, 26 Oct. 2017

Effects of eccentrically whirling motion of a Magnetically levitated impeller on blood damage potential in a centrifugal blood pump　　　　　　　　　　　　　　　
Shuya Shida; Toru Masuzawa; Masahiro Osa
2017 The International society for mechanical circulatory support (ISMCS), 16 Oct. 2017

Performance evaluation of a magnetically levitated centrifugal pediatric VAD and motor design optimization for improvement of a maglev motor　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi
2017 The International society for mechanical circulatory support (ISMCS), 16 Oct. 2017

体外循環磁気浮上血液ポンプにおける浮上回転インペラ不釣り合いの径方向変位への影響　　　　　　　　　　　　　　　
大野康平; 増澤徹; 長真啓; 佐藤遼太; 西村隆; 許俊鋭
LIFE2017, 15 Sep. 2017

補助人工心臓のための4軸制御型磁気軸受の開発－3次元静磁場解析による軸受形状検討－　　　　　　　　　　　　　　　
小泉綾香; 増澤徹; 長真啓
LIFE2017, 15 Sep. 2017

複合低エネルギを用いた冠動脈バイパス手術支援デバイスの開発－吻合時温度変化の検討－　　　　　　　　　　　　　　　
羽根田洋輔; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫
LIFE2017, 15 Sep. 2017

Compact maglev motor with full DOF active control for miniaturized rotary blood pumps　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Ryoga Orihara; Eisuke Tatsumi
The 11th International Symposium on Linear Drives for Induatry Applications(LDIA2017), 06 Sep. 2017

反発型永久磁石磁気軸受による磁気浮上全人工心臓の安定化　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 長真啓; 國府田芳彰; Daniel Timms
第55回日本人工臓器学会大会, 01 Sep. 2017

磁気浮上型体外循環血液ポンプの血液適合性向上のための浮上インペラ振れ回り運動解析　　　　　　　　　　　　　　　
佐藤遼太; 増澤徹; 長真啓; 信太宗也; 大野康平; 西村隆; 許俊鋭
第55回日本人工臓器学会大会, 01 Sep. 2017

小型5軸制御磁気浮上モータを用いた小児用人工心臓のポンプ性能評価　　　　　　　　　　　　　　　
織原涼雅; 増澤徹; 長真啓; 巽英介
第55回日本人工臓器学会大会, 01 Sep. 2017

乳児・小児用磁気浮上補助人工心臓の開発　　　　　　　　　　　　　　　
増澤徹; 長真啓; 巽英介
第55回日本人工臓器学会大会, 01 Sep. 2017

磁気浮上型全人工心臓の流量バランス制御に関する研究　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 長真啓; Daniel L Timms
第25回茨城講演会, 29 Aug. 2017

磁気支持安定性向上を目指した三次元磁場解析による小児用人工心臓用5軸制御磁気浮上モータの構造検討　　　　　　　　　　　　　　　
織原涼雅; 増澤徹; 長真啓; 巽英介
第25回茨城講演会, 29 Aug. 2017

磁気浮上型血液ポンプ内浮上インペラの羽根枚数が径方向変位に与える影響　　　　　　　　　　　　　　　
大野康平; 増澤徹; 長真啓; 佐藤遼太; 西村隆; 許俊鋭
第25回茨城講演会, 29 Aug. 2017

複合低エネルギを用いた冠動脈バイパス手術支援デバイスの開発－血管装着部の変更・加圧機構の改良－　　　　　　　　　　　　　　　
羽根田洋輔; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫
第25回茨城講演会, 29 Aug. 2017

5軸制御磁気浮上モータを用いた遠心式小児用人工心臓の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 斎藤拓也; 巽英介
第29回「電磁力関連のダイナミクス」シンポジウム, 18 May 2017

薄小型補助人工心臓用セルフベアリングモータの改良　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第29回「電磁力関連のダイナミクス」シンポジウム, 18 May 2017

磁気浮上遠心血液ポンプ設計のためのインペラ変位を考慮した数値流体解析　　　　　　　　　　　　　　　
信太宗也; 増澤徹; 長真啓
第56回日本生体医工学会大会, 03 May 2017

全置換型人工心臓の高度化に関する研究　　　　　　　　　　　　　　　
國府田芳彰; 増澤徹; 長真啓; 牧田丈靖; Daniel L Timms
第26回ライフサポート学会フロンティア講演会, 10 Mar. 2017

心臓治療を目的とした心拍同期型体外循環磁気浮上血液ポンプの研究開発　　　　　　　　　　　　　　　
大野康平; 増澤徹; 長真啓; 佐藤遼太; 西村隆; 許俊鋭
第26回ライフサポート学会フロンティア講演会, 10 Mar. 2017

複合低エネルギーを用いた冠動脈バイパス手術支援デバイスの研究開発　　　　　　　　　　　　　　　
羽根田洋輔; 増澤徹; 尾関和秀; 岸田晶夫; 樋上哲哉
第26回ライフサポート学会フロンティア講演会, 10 Mar. 2017

作動流体粘度が磁気浮上補助人工心臓のポンプ・浮上性能に与える影響　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第26回ライフサポート学会フロンティア講演会, 10 Mar. 2017

全置換型磁気浮上人工心臓の流量バランス制御に関する研究　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 長真啓; 國府田芳彰; Daniel L Timms
第26回ライフサポート学会フロンティア講演会, 10 Mar. 2017

小児用人工心臓のための小型5軸制御磁気浮上モータの改良　　　　　　　　　　　　　　　
織原涼雅; 長真啓; 増澤徹; 斎藤拓也; 巽英介
第26回ライフサポート学会フロンティア講演会, 10 Mar. 2017

磁気浮上型小児用補助人工心臓の研究開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 斎藤卓也; 巽英介
第45回人工心臓と補助循環懇話会学術集会, 17 Feb. 2017

磁気浮上血液ポンプのマグネットカプリング機構の設計　　　　　　　　　　　　　　　
小泉綾香; 増澤徹; 國府田芳彰; 長真啓
第29回バイオエンジニアリング講演会, 19 Jan. 2017

磁気浮上型全人工心臓の課題　　　　　　　　　　　　　　　
増澤徹; Daniel Timms
第54回日本人工臓器学会大会, 25 Nov. 2016, [Invited]

薄小型補助人工心臓のための径方向2軸制御型磁気浮上カスケードポンプの開発　　　　　　　　　　　　　　　
辺 保昭; 増澤 徹; 村上 倫子; 小沼 弘幸; 西村 隆; 許 俊鋭
第25回MAGDAコンファレンス, 24 Nov. 2016

全置換型磁気浮上人工心臓のための反発型磁気軸受の検討　　　　　　　　　　　　　　　
國府田 芳彰; 増澤 徹; 長 真啓; Daniel L TIMMS
第25回MAGDAコンファレンス, 24 Nov. 2016

超小型磁気浮上式小児用人工心臓の開発　　　　　　　　　　　　　　　
斎藤拓也; 増澤徹; 長真啓; 巽英介
第25回MAGDAコンファレンス, 24 Nov. 2016

Miniaturization of pediatric ventricular assist device with a double stator maglev motor　　　　　　　　　　　　　　　
Takuya Saito; Toru Masuzawa; Masahiro Osa; Eisuke Tatsumi
24th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2016

Performance enhancement of magliv ventricular assist device for mild heart disease patients　　　　　　　　　　　　　　　
Yasuaki Watanabe; Toru Masuzawa; Michiko Murakami; Hiroyuki Onuma; Takashi Nishimura; Shunei Kyo
24th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2016

Improvement in a next generation maglev centrifugal pediatric VAD　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Takuya Saito; Eisuke Tatsumi
24th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2016

Magnetically levitated blood pump for extracorporeal circulation driven to synchronize with heart beat　　　　　　　　　　　　　　　
Ryota Sato; Toru Masuzawa; Masahiro Osa; Takashi Nishimura; Shunei Kyo; Noritsugu Naito; Eisuke Tatsumi
24th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2016

Maglev motor optimization for single rotating actuator total artificial heart　　　　　　　　　　　　　　　
Yoshiaki Koda; Toru Masuzawa; Masahiro Osa; Daniel Lee Timms
24th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2016

The investigation of hydrodynamic effect of the 3D micro-geometrical structures on physical adhesion phenomena of thrombus foemation　　　　　　　　　　　　　　　
Akiko Oota; Toru Masuzawa; Kazuaki Nagayama
24th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2016

全置換型人工心臓用磁気浮上モータの改良　　　　　　　　　　　　　　　
國府田芳彰; 増澤徹; 長真啓; Timms Daniel
LIFE2016, 04 Sep. 2016

Effect of pulsatile operation on a maglev centrifugal blood pump　　　　　　　　　　　　　　　
Toru Masuzawa
2016 Annual Conference of the Asia-Pacific Society for Artificial Organs, 27 Aug. 2016

心臓治療を目的とした磁気浮上型体外循環血液ポンプの研究開発　　　　　　　　　　　　　　　
佐藤遼太; 増澤徹; 長真啓; 西村隆; 許俊鋭
第24回茨城講演会, 26 Aug. 2016

複合低エネルギ生体組織接合技術における生体組織構造変化の可視化　　　　　　　　　　　　　　　
小泉綾香; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫
第24回茨城講演会, 26 Aug. 2016

Magnetic levitation performance of miniaturized magnetically levitated motor with 5-DOF active control　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Takuya Saito; Eisuke Tatsumi
15th International symposium on magnetic bearings, 03 Aug. 2016

Magnetic Levitation Performance of Miniaturized Magnetically Levitated Motor with 5-DOF Active Control　　　　　　　　　　　　　　　
Masahiro OSA; Toru MASUZAWA; Takuya SAITO and Eisuke TATSUMI
15th International Symposium on Magnetic Bearings, 03 Aug. 2016

Development of radial type self-bearing motor for small centrifugal blood pump　　　　　　　　　　　　　　　
Hiroyuki ONUMA; Toru MASUZAWA and Michiko MURAKAMI
15th International Symposium on Magnetic Bearings, 03 Aug. 2016

The effect of 3-dimential micro-geometrical structures of bio-material surface on flow and adhesion phase in thrombus cascade　　　　　　　　　　　　　　　
Toru Masuzawa
ASAIO 62nd Annual Conference, 15 Jun. 2016

小児用人工心臓用5軸制御磁気浮上モータのセンサレスモータ制御　　　　　　　　　　　　　　　
長真啓; 増澤徹; 斎藤拓也; 巽英介
第28回「電磁力関連のダイナミクス」シンポジウム, 18 May 2016

薄小型磁気浮上補助人工心臓の実用化に向けた改良　　　　　　　　　　　　　　　
渡辺保昭; 増澤徹; 村上倫子; 小沼弘幸; 西村隆; 許俊鋭
第55回日本生体医工学会大会, 26 Apr. 2016

レオメータを使用したせん断流れ場における血液接触面の表面粗さと溶血量の関係　　　　　　　　　　　　　　　
中嶋翔太; 丸山修; 西田正浩; 足立吉數; 長真啓; 増澤徹
第55回日本生体医工学会大会, 26 Apr. 2016

人工心臓技術の現況と今後の展望　　　　　　　　　　　　　　　
増澤徹; 長真啓; 柴建次; 巽英介; 西村隆; 許俊鋭; Daniel Timms
日本医工学治療学会第32回学術大会, 20 Mar. 2016, [Invited]

複合低エネルギ生体組織接合技術の研究開発－FIB-SEMによる生体組織接合部の観察－　　　　　　　　　　　　　　　
小泉綾香; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫
ライフサポート学会第25回フロンティア講演会, 08 Mar. 2016

心拍同期型磁気浮上血液ポンプにおける受動安定性向上のための検討　　　　　　　　　　　　　　　
下堀拓己; 増澤徹; 長真啓; 西村隆; 許俊鋭
ライフサポート学会第25回フロンティア講演会, 08 Mar. 2016

磁気浮上型体外循環血液ポンプの拍動運動における流体力推定　　　　　　　　　　　　　　　
佐藤遼太; 増澤徹; 長真啓; 下堀拓己; 西村隆; 許俊鋭
ライフサポート学会第25回フロンティア講演会, 08 Mar. 2016

連続流式小児用磁気浮上心臓の研究開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 斎藤拓也; 巽英介
第44回人工心臓と補助循環懇話会学術集会, 04 Mar. 2016

磁気浮上人工心臓の制御　　　　　　　　　　　　　　　
増澤徹; 西村隆; 許俊鋭; 巽英介; Daniel Timms
第44回人工心臓と補助循環懇話会学術集会, 04 Mar. 2016

急性心不全適用を目指した体外循環磁気浮上ポンプの開発　　　　　　　　　　　　　　　
増澤徹; 下堀拓己; 内藤啓嗣; 巽英介; 西村隆; 許俊鋭
日本定常流ポンプ研究会2015, 19 Nov. 2015

次世代型磁気浮上式小児用補助人工心臓の開発現状　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第53回日本人工臓器学会大会, 19 Nov. 2015

薄小型磁気浮上補助人工心臓における非制御軸方向の振動と流体力　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第53回日本人工臓器学会大会, 19 Nov. 2015

循環系シミュレータの冠循環模擬評価　　　　　　　　　　　　　　　
黒崎亘; 増澤徹
第53回日本人工臓器学会大会, 19 Nov. 2015

連続流型磁気浮上全人工心臓の開発　　　　　　　　　　　　　　　
箕輪純承; 増澤徹; 長真啓; 國府田芳彰
第53回日本人工臓器学会大会, 19 Nov. 2015

人工材料上の表面粗さ周囲に発生する流れと血栓形成に関する基礎研究～幾何学構造周囲流れの予測と成分付着の関係～　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 柴田隆行
第53回日本人工臓器学会大会, 19 Nov. 2015

センサレスモータ制御を用いた磁気浮上血液ポンプの回転数変調　　　　　　　　　　　　　　　
長真啓; 増澤徹; 下堀拓己; 西村隆; 許俊鋭
第58回自動制御連合講演会, 14 Nov. 2015

ラジアル型セルフベアリングモータにおける受動安定性の簡易推定式の検討　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹; 村上倫子
第24回MAGDAコンファレンス, 12 Nov. 2015

磁気浮上型人工心臓のための永久磁石磁気カップリングの基礎検討　　　　　　　　　　　　　　　
國府田芳彰; 増澤徹; 長真啓; Kieran Hunter
第24回MAGDAコンファレンス, 12 Nov. 2015

心拍同期型磁気浮上血液ポンプにおける受動安定軸の浮上安定性評価　　　　　　　　　　　　　　　
下堀拓己; 増澤徹; 西村隆; 許俊鋭
第24回MAGDAコンファレンス, 12 Nov. 2015

Magnetically suspended total artificial heart with a single actuator　　　　　　　　　　　　　　　
Toru Masuzawa
APSAO2015, 24 Oct. 2015

A double side stator type axial self-bearing motor development for the left ventricular assist device　　　　　　　　　　　　　　　
Nobuyuki Kurita; Takeo Ishikawa; Naoki Saito; Toru Masuzawa
The 17th International Symposium on Applied Electromagnetics and Mechanics, 15 Sep. 2015

Ministurizing 5-DOF fully controlled axial gap maglev motor for pediatric ventricular assist devices　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Naoki Omori; Eisuke Tatsumi
The 17th International Symposium on Applied Electromagnetics and Mechanics, 15 Sep. 2015

小児用人工心臓用5軸制御磁気浮上モータの小型化　　　　　　　　　　　　　　　
斎藤拓也; 増澤徹; 長真啓; 巽英介
第23回茨城講演会, 28 Aug. 2015

ホモポーラ型ハイブリッド5軸制御セルフベアリングモータに関する研究　　　　　　　　　　　　　　　
鈴木力; 松田健一; 岡田養二; 近藤良; 増澤徹
第23回茨城講演会, 28 Aug. 2015

ＩＰＭ型5軸制御セルフベアリングモータに関する研究　　　　　　　　　　　　　　　
徳井春彦; 松田健一; 近藤良; 増澤徹
第23回茨城講演会, 28 Aug. 2015

コンシクエントポール型5軸制御セルフベアリングモータの基本特性解析　　　　　　　　　　　　　　　
原田誠; 松田健一; 近藤良; 増澤徹
第23回茨城講演会, 28 Aug. 2015

二重円筒型レオメータによる人工材料溶血定量評価　　　　　　　　　　　　　　　
中嶋翔太; 丸山修; 西田正浩; 足立吉數; 長真啓; 増澤徹
第23回茨城講演会, 28 Aug. 2015

全置換型磁気浮上人工心臓の研究開発－エネルギ伝送技術を用いた径方向変位抑制機構－　　　　　　　　　　　　　　　
國府田芳彰; 増澤徹; 箕輪純承; 長真啓; 柴建次; Daniel L Timms
第23回茨城講演会, 28 Aug. 2015

数値流体解析による薄小型磁気浮上補助人工心臓用カスケードポンプの改良　　　　　　　　　　　　　　　
渡辺保昭; 増澤徹; 村上倫子; 小沼弘幸; 西村隆; 許俊鋭
第23回茨城講演会, 28 Aug. 2015

スパッタリング法による水熱結晶化マグネシウム含有HA薄膜の溶解性及び密着性評価　　　　　　　　　　　　　　　
第23回茨城講演会, 28 Aug. 2015

磁性粒子を用いた磁気励振細胞刺激機構の開発　　　　　　　　　　　　　　　
西村佳織; 増澤徹; 長真啓; 林照剛; 岸田晶夫
第27回「電磁力関連のダイナミクス」シンポジウム, 14 May 2015

小児用人工心臓のための5軸制御磁気浮上モータの回転速度センサレス制御　　　　　　　　　　　　　　　
長真啓; 増澤徹; 大森直樹; 巽英介
第27回「電磁力関連のダイナミクス」シンポジウム, 14 May 2015

Mechanical circulatory supportのための磁気浮上血液ポンプ　　　　　　　　　　　　　　　
増澤徹
第54回生体医工学会大会, 07 May 2015

人工材料表面上での微小流れと抗血栓性に関する研究　　　　　　　　　　　　　　　
山口直紀
関東学生会第54回学生員卒業研究発表講演会, 20 Mar. 2015

複合低エネルギ生体組織接合技術の開発研究－コラーゲン変性可視化による至適接合条件の検討－　　　　　　　　　　　　　　　
諏訪陽祐; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫; 樋上哲哉
第24回ライフサポート学会フロンティア講演会, 05 Mar. 2015

小児用磁気浮上人工心臓の小型化設計　　　　　　　　　　　　　　　
斎藤拓也; 増澤徹; 長真啓; 大森直樹; 巽英介
第24回ライフサポート学会フロンティア講演会, 05 Mar. 2015

全置換型人工心臓のための磁気浮上モータの改良　　　　　　　　　　　　　　　
國府田芳彰; 増澤徹; 長真啓; 箕輪純承; Daniel L Timms
第24回ライフサポート学会フロンティア講演会, 05 Mar. 2015

薄小型磁気浮上補助人工心臓用カスケードポンプの改良　　　　　　　　　　　　　　　
渡辺保昭; 増澤徹; 村上倫子; 吉田翔一; 小沼弘幸; 西村隆; 許俊鋭
第24回ライフサポート学会フロンティア講演会, 05 Mar. 2015

人工心臓材料表面性状と血液適合性に関する研究－人工材料表面粗さが溶血に及ぼす影響の検討－　　　　　　　　　　　　　　　
中嶋翔太; 丸山修; 西田正浩; 足立吉數; 増澤徹
第24回ライフサポート学会フロンティア講演会, 05 Mar. 2015

乳幼児、小児用補助人工心臓のための磁気浮上モータの小型化　　　　　　　　　　　　　　　
長真啓; 増澤徹; 大森直樹; 巽英介
第43回人工心臓と補助循環懇話会学術集会, 20 Feb. 2015

磁気浮上型心臓治療用血液ポンプへのセンサレスモータ制御の適用　　　　　　　　　　　　　　　
大森直樹; 増澤徹; 長真啓; 下堀拓己; 西村隆; 許俊鋭
第23回MAGDAコンファレンスin 高松, 04 Dec. 2014

薄小型磁気浮上補助心臓における浮上インペラの受動安定軸の変動計測　　　　　　　　　　　　　　　
吉田翔一; 増澤徹; 村上倫子; 小沼弘幸; 西村隆; 許俊鋭
第23回MAGDAコンファレンスin 高松, 04 Dec. 2014

ホモポーラ型ハイブリット5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
加藤正寛; 松田健一; 岡田養二; 近藤良; 増澤徹
第23回MAGDAコンファレンスin 高松, 04 Dec. 2014

The relationship between the thrombogenicity and the generated flow around 3-dimensional micro geometrical structures on the bio-material –Investigation of micro flow－　　　　　　　　　　　　　　　
Ota-Ishigaki A; Masuzawa T; Shibata T; Kawashima T; Maruyama O
The 10th International Student Conference at Ibaraki University, 15 Nov. 2014

Cardiovascular circulation simulator to evaluate ventricular assist effect　　　　　　　　　　　　　　　
Kurosaki W; Masuzawa T
The 10th International Student Conference at Ibaraki University, 15 Nov. 2014

全置換型磁気浮上人工心臓への反発型永久磁石磁気軸受の組み込み　　　　　　　　　　　　　　　
牧田丈靖; 増澤徹; 國府田芳彰; 長真啓; Daniel L Timms
第26回MAGDAコンファレンス in 金沢, 26 Oct. 2014

重症化予防のための薄小型磁気浮上補助人工心臓　　　　　　　　　　　　　　　
増澤徹; 村上倫子; 吉田翔一; 長真啓; 小沼弘幸; 許俊鋭; 西村隆; 柴建次
第52回日本人工臓器学会大会, 17 Oct. 2014

冠循環模擬を付加した循環系シミュレータの性能評価　　　　　　　　　　　　　　　
黒崎亘; 増澤徹; 箕輪純承
第52回日本人工臓器学会大会, 17 Oct. 2014

5軸制御磁気浮上モータを用いた乳幼児、小児用補助人工心臓の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 大森直樹; 巽英介
第52回日本人工臓器学会大会, 17 Oct. 2014

全置換型磁気浮上人工心臓：BiVACORとIBHeart　　　　　　　　　　　　　　　
増澤徹; Daniel Timms; Shaun Gregory
日本定常流ポンプ研究会2014, 17 Oct. 2014

複合低エネルギ生体組織接合のおける生体組織含水率と接合強度の関係　　　　　　　　　　　　　　　
諏訪陽祐; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫; 樋上哲哉
生活生命支援医療福祉工学系学会連合大会, 24 Sep. 2014

薄小型補助人工心臓磁気浮上インペラの非制御軸挙動　　　　　　　　　　　　　　　
吉田翔一; 増澤徹; 村上倫子; 長真啓; 小沼弘幸; 西村隆; 許俊鋭
生活生命支援医療福祉工学系学会連合大会, 24 Sep. 2014

Pediatric VAD with five degrees of freedom control maglev motor　　　　　　　　　　　　　　　
Toru Masuzawa
the 41st Annual ESAO Congress, 17 Sep. 2014

スパッタリング法によるマグネシウム置換HA薄膜の作製とマグネシウム置換量の評価　　　　　　　　　　　　　　　
但野ちなみ; 尾関和秀; 増澤徹; 青木秀希
第22回茨城講演会, 05 Sep. 2014

ケイ酸塩またはHA粉末を用いた放射性物質吸着とケイ酸塩/HA複合体作成方法の検討　　　　　　　　　　　　　　　
大和田詠里; 尾関和秀; 増澤徹; 青木秀希
第22回茨城講演会, 05 Sep. 2014

複合低エネルギ生体組織接合技術を利用した冠動脈バイパス手術支援デバイスの研究開発　　　　　　　　　　　　　　　
荒昌幸; 増澤徹; 長真啓; 尾関和秀; 岸田晶夫; 樋上哲哉
第22回茨城講演会, 05 Sep. 2014

生体組織融着技術におけるステントの加熱手法の基礎的検討　　　　　　　　　　　　　　　
豊田裕史; 田代翔子; 橋本一生; 柴建次; 岸田晶夫; 木村剛; 尾関和秀; 増澤徹
第22回茨城講演会, 05 Sep. 2014

急性心不全のための心拍同期型磁気浮上ポンプの研究開発　　　　　　　　　　　　　　　
下堀拓己; 増澤徹; 長真啓; 西村隆; 許俊鋭
第22回茨城講演会, 05 Sep. 2014

冠循環模擬機構を有する循環系シミュレータの開発　　　　　　　　　　　　　　　
箕輪純承; 増澤徹; 黒崎亘; 長真啓
第22回茨城講演会, 05 Sep. 2014

Magnetically Suspended Motor System for Artificial Hearts and Blood Pumps　　　　　　　　　　　　　　　
Toru Masuzawa
14th International Symposium on Magnetic Bearings, 11 Aug. 2014

Radial position Active Control of Double Stator Axial Gap Self-Bearing Motor for Peadiatric VAD　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Naoki Omori; Eisuke Tatsumi
14th International Symposium on Magnetic Bearings, 11 Aug. 2014

Thin Maglev Ventricular Assist Device with Radial Type Self-Bearing Motor　　　　　　　　　　　　　　　
Michiko Murakami; Toru Masuzawa; Shoichi Yoshida; Hiroyuki Onuma; Takashi Nishimura; Syunei Kyo
14th International Symposium on Magnetic Bearings, 11 Aug. 2014

Evaluation of magnetic Suspension Characteristics and Levitation Performance of a centrifugal Blood pump Using Radial Type Self-Bearing Motor　　　　　　　　　　　　　　　
Hiroyuki Onuma; Toru Masuzawa
14th International Symposium on Magnetic Bearings, 11 Aug. 2014

Optimization design of magnetically suspended system for the BIVACOR total artificial heart　　　　　　　　　　　　　　　
Kurita N; Timm D; Greatrex N; Kleinheyer M; Masuzawa T
14th International Symposium on Magnetic Bearings, 11 Aug. 2014

Magnetically Suspended Artificial Heart　　　　　　　　　　　　　　　
Toru Masuzawa
8th Asia-Pacific Symposium on Applied Electromagnetics and Mechanics, 22 Jul. 2014, [Invited]

シングル磁気浮上モータを使用した全置換型人工心臓　　　　　　　　　　　　　　　
増澤徹; ティムス ダニエル
第53回日本生体医工学会大会, 24 Jun. 2014

循環補助デバイスのための渦流（カスケード）ポンプ　　　　　　　　　　　　　　　
増澤徹; 村上倫子
第53回日本生体医工学会大会, 24 Jun. 2014

小児用補助人工心臓のための小型磁気浮上モータの開発　　　　　　　　　　　　　　　
大森直樹; 増澤徹; 長真啓; 巽英介
第26回「電磁力関連のダイナミクス」シンポジウム, 21 May 2014

磁気ビーズを用いた磁気励振細胞刺激システム　　　　　　　　　　　　　　　
増澤徹; 服部圭介; 林照剛; 木村剛; 岸田晶夫
第26回「電磁力関連のダイナミクス」シンポジウム, 21 May 2014

全置換型磁気浮上人工心臓と流量バランス制御　　　　　　　　　　　　　　　
山田悠; 増澤徹; Daniel L Timms
第26回「電磁力関連のダイナミクス」シンポジウム, 21 May 2014

回転数周期的変動時の磁気浮上型血液ポンプの浮上安定性と溶血性能の検討　　　　　　　　　　　　　　　
増澤徹; 山口聡史; 下堀拓己; 西村隆; 許俊鋭
第26回「電磁力関連のダイナミクス」シンポジウム, 21 May 2014

新しい循環治療方法の評価を目指した循環系シミュレータの研究開発　　　　　　　　　　　　　　　
箕輪純承; 増澤徹; 黒崎亘
関東学生会第53回学生員卒業研究発表講演会, 14 Mar. 2014

乳幼児, 小児に適用可能な磁気浮上補助人工心臓の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 大森直樹; 巽英介
第42回人工心臓と補助循環懇話会学術集会, 07 Mar. 2014

左右心流量バランス機能を有した全置換型磁気浮上人工心臓　　　　　　　　　　　　　　　
山田悠; 増澤徹; ティムズダニエル
第42回人工心臓と補助循環懇話会学術集会, 07 Mar. 2014

薄型補助人工心臓の開発　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第42回人工心臓と補助循環懇話会学術集会, 07 Mar. 2014

全置換型磁気浮上人工心臓と流量バランス制御の研究　　　　　　　　　　　　　　　
山田悠; 増澤徹
第23回ライフサポート学会フロンティア講演会, 28 Feb. 2014

磁気浮上型心臓治療用血液ポンプのインペラの浮上安定性の検討　　　　　　　　　　　　　　　
下堀拓己; 増澤徹; 山口聡史; 西村隆; 許俊鋭
第23回ライフサポート学会フロンティア講演会, 28 Feb. 2014

複合低エネルギ生体組織接合技術を利用した冠動脈バイパス手術支援デバイスの開発　　　　　　　　　　　　　　　
荒昌幸; 増澤徹; 尾関和秀; 岸田晶夫; 樋上哲哉
第23回ライフサポート学会フロンティア講演会, 28 Feb. 2014

小児、乳児用人工心臓のための5軸制御磁気浮上モータ　　　　　　　　　　　　　　　
長真啓; 増澤徹; 大森直樹; 巽英介
第23回ライフサポート学会フロンティア講演会, 28 Feb. 2014

薄型磁気浮上補助人工心臓における受動安定特性の検討　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第22回MAGDAコンファレンスin宮崎, 02 Dec. 2013

12突極ラジアル型セルフベアリングモータの磁気支持特性の推定　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹
第22回MAGDAコンファレンスin宮崎, 02 Dec. 2013

磁気浮上型血液ポンプのセンサレスモータ制御　　　　　　　　　　　　　　　
床井宏行; 増澤徹; 山口聡史; 西村隆; 許俊鋭
第22回MAGDAコンファレンスin宮崎, 02 Dec. 2013

小児用人工心臓のための小型5軸制御セルフベアリングモータ　　　　　　　　　　　　　　　
長真啓; 増澤徹; 大森直樹; 巽英介
第22回MAGDAコンファレンスin宮崎, 02 Dec. 2013

アウターロータ型5軸制御セルフベアリングモータに関する研究　　　　　　　　　　　　　　　
松田健一; 平根龍也; 近藤良; 増澤徹
第22回MAGDAコンファレンスin宮崎, 02 Dec. 2013

生体組織融着技術を用いた血管吻合装置の開発－加圧バンドを用いた場合の融着強度評価－　　　　　　　　　　　　　　　
橋本一生; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
リニアドライブ研究会, 07 Oct. 2013, 電気学会

ゼロパワー制御を用いた磁気浮上全人工心臓の流量バランス制御　　　　　　　　　　　　　　　
山田悠; 増澤徹; ティムズダニエル
リニアドライブ研究会, 07 Oct. 2013

The thin maglev ventricular assist device for mild heart disease patients　　　　　　　　　　　　　　　
Michiko Murakami; Toru Masuzawa; Hiroyuki Onuma; Takashi Nishimura; Syunei Kyo
21th ISRBP2013 YOKOHAMA, 26 Sep. 2013

Development of the left ventricular assist device by use of the double side stator type axial magnetically levitated motor　　　　　　　　　　　　　　　
Nobuyuki Kurita; Takeo Ishikawa; Hirohumi Takada; Toru Masuzawa
21th ISRBP2013 YOKOHAMA, 26 Sep. 2013

Hemolysis characteristics of maglev blood pump operated in the pulsatile mode　　　　　　　　　　　　　　　
Satoshi Yamaguchi; Toru Masuzawa; Takashi Nishimura; Shunei Kyo
21th ISRBP2013YOKOHAMA, 26 Sep. 2013

Performance improvement of two-DOF control self-bearing motor for maglev centrifugal blood pump　　　　　　　　　　　　　　　
Hiroyuki Onuma; Toru Masuzawa
21th ISRBP2013 YOKOHAMA, 26 Sep. 2013

Characterizing the magnetic motor-bearing of a rotary TAH to improve pressuresensitivity　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Hiroyuki Tokoi; Nobuyuki Kurita; Nicholas Greatrex; Daniel Timms
21th ISRBP2013 YOKOHAMA, 26 Sep. 2013

Magnetically suspended total artificial heart with a single maglev motor　　　　　　　　　　　　　　　
Yu Yamada; Toru Masuzawa; Daniel Lee Timms
21th ISRBP2013YOKOHAMA, 26 Sep. 2013

A small thin maglev ventoricular assist device for mild heart disease patients　　　　　　　　　　　　　　　
Toru Masuzawa; Michiko Murakami; Yusuke Sakata; Shoichi Yoshida; Hiroyuki Onuma; Takashi Nisimura; Syunei Kyo
5th Congress of the International Federation for Artificial Organs (IFAO2013), 26 Sep. 2013

Observation of collagens’ microscopic structure change to investigate the adhesion mechanism combined low level energies　　　　　　　　　　　　　　　
Yosuke Suwa; Toru Masuzawa; Kwangwoo Nam; Tsuyoshi Kimura; Akio Kishida
5th Congress of the International Federation for Artificial Organs (IFAO2013), 26 Sep. 2013

The mechanical cell stimulator using alternative magnetic field eith magnetic beads attached on the cell　　　　　　　　　　　　　　　
Keisuke Hattori; Toru Masuzawa; Terutake Hayashi
5th Congress of the International Federation for Artificial Organs (IFAO2013), 26 Sep. 2013

Motor performance of magnetically levitated paediatric VAD　　　　　　　　　　　　　　　
Naoki Omori; Toru Masuzawza; Masahiro Osa; Eisuke Tatsumi
5th Congress of the International Federation for Artificial Organs (IFAO2013), 26 Sep. 2013

Magnetically suspended total artificial heart with a single actuator　　　　　　　　　　　　　　　
T.Masuzawa; N.Nishimura; D.L.Timms
XL ESAO Annual Congress, 11 Sep. 2013

薄型磁気浮上補助人工心臓のための動圧スラスト軸受　　　　　　　　　　　　　　　
吉田翔一; 増澤徹; 村上倫子; 坂田祐介; 小沼弘幸; 西村隆; 許俊鋭
第21回茨城講演会, 06 Sep. 2013

小児用人工心臓への応用を目指した5軸制御型小型磁気浮上モータの開発　　　　　　　　　　　　　　　
大森直樹; 増澤徹; 長真啓; 巽英介
第21回茨城講演会, 06 Sep. 2013

コンシクエントポール型セルフベアリングモータの基本特性解析　　　　　　　　　　　　　　　
加藤正寛; 松田健一; 岡田養二; 近藤良; 増澤徹
第21回茨城講演会, 06 Sep. 2013

生体組織融着技術を用いたステントの位置ずれ防止－小型コイルによるステントの誘導加熱と引張強度評価－　　　　　　　　　　　　　　　
田代翔子; 橋本一生; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
第21回茨城講演会, 06 Sep. 2013

複合低エネルギ生体組織接合に関する研究－加圧熱によるコラーゲンフィブリルの幾何学的形状変化－　　　　　　　　　　　　　　　
諏訪陽祐; 増澤徹; 南広祐; 木村剛; 岸田晶夫
第21回茨城講演会, 06 Sep. 2013

アパタイトおよびケイ酸塩を用いた放射性物質除去に関する研究　　　　　　　　　　　　　　　
大和田詠里; 尾関和秀; 増澤徹; 青木秀希
生活生命支援医療福祉工学系学会連合大会, 02 Sep. 2013

生体組織融着技術を用いた血管吻合装置の開発－ステントの加熱と融着強度の評価－　　　　　　　　　　　　　　　
橋本一生; 田代翔子; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
生活生命支援医療福祉工学系学会連合大会, 02 Sep. 2013

せん断流れ場における血液接触面の表面粗さが溶血量増加に及ぼす定量評価－せん断応力発生の関与について－　　　　　　　　　　　　　　　
丸山修; 工藤大樹; 西田正浩; 山根隆志; 松田健一; 足立吉數; 増澤徹
生活生命支援医療福祉工学系学会連合大会, 02 Sep. 2013

複合低エネルギ生体組織接合に関する研究－加圧機によるコラーゲンフィブリルの幾何学的形状変化の検討－　　　　　　　　　　　　　　　
諏訪陽祐; 増澤徹; 南広祐; 木村剛; 岸田晶夫
生活生命支援医療福祉工学系学会連合大会, 02 Sep. 2013

磁気ビーズを用いた細胞振動刺激装置及びナノ振動検出装置の研究開発　　　　　　　　　　　　　　　
服部圭介; 増澤徹; 林照剛
生活生命支援医療福祉工学系学会連合大会, 02 Sep. 2013

小児用人工心臓のための小型磁気浮上モータにおけるロータ永久磁石形状の検討　　　　　　　　　　　　　　　
大森直樹; 増澤徹; 長真啓; 巽英介
生活生命支援医療福祉工学系学会連合大会, 02 Sep. 2013

全人工心臓用モータ小型化の検討　　　　　　　　　　　　　　　
床井宏行; 増澤徹; Daniel L Timms
第25回「電磁力関連のダイナミクス」シンポジウム, 15 May 2013

心機能回復のための磁気浮上型血液ポンプの動特性に関する検討　　　　　　　　　　　　　　　
山口聡史; 増澤徹; 大森正芳; 前田裕之; 西村隆; 許俊鋭
第25回「電磁力関連のダイナミクス」シンポジウム, 15 May 2013

薄型磁気浮上摩擦血液ポンプにおける非制御軸の安定性への流体力の影響　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 坂田佑介; 小沼弘幸; 西村隆; 許俊鋭
第25回「電磁力関連のダイナミクス」シンポジウム, 15 May 2013

ストロンチウム固溶ハイドロキシアパタイト薄膜の作製と骨芽細胞による評価　　　　　　　　　　　　　　　
星野智大; 尾関和秀; 後藤哲哉; 増澤徹; 青木秀希
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

カテーテル搭載用小型コイルを用いた食道用ステントの誘導加熱－小型コイルの開発と評価－　　　　　　　　　　　　　　　
田代翔子; 橋本一生; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

複合低エネルギを用いた腹腔鏡手術用鉗子型接合デバイスの開発　　　　　　　　　　　　　　　
中島彩; 青代敏行; 増澤徹; 尾関和秀; 岸田晶夫; 樋上哲哉
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

複合低エネルギ接合を利用した人工心臓用脱血管の研究　　　　　　　　　　　　　　　
佐々木悠祐; 青代敏行; 増澤徹; 尾関和秀; 岸田晶夫; 巽英介
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

生体組織・金属接合のための電磁誘導加熱に関する研究　　　　　　　　　　　　　　　
横須賀匠; 増澤徹; 橋本英子; 柴建次
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

細胞振動印加装置及びナノ振動検出装置の研究開発　　　　　　　　　　　　　　　
放生宏貴; 増澤徹; 服部圭介; 林照剛
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

小型磁気浮上摩擦血液ポンプのための動圧軸受の研究開発,　　　　　　　　　　　　　　　
吉田翔一; 増澤徹; 村上倫子; 坂田 祐介; 小沼弘幸; 西村隆; 許俊鋭
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

小児用磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
大森直樹; 増澤徹; 長真啓; 巽英介
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

人工材料表面の3次元マイクロドメイン幾何学構造と血液適合性に関する研究　　　　　　　　　　　　　　　
古河翔多; 増澤徹; 太田晶子; 柴田隆行; 川島貴弘
第22回ライフサポート学会フロンティア講演会, 02 Mar. 2013

新しい治療デバイスと磁気浮上技術　　　　　　　　　　　　　　　
増澤徹; 西村隆; 許俊鋭; 巽英介; TIMMS Daniel
第41回人工心臓と補助循環懇話会学術集会, 01 Feb. 2013

BiVACOR－Implantable Rotary Total Artificial Heart　　　　　　　　　　　　　　　
TIMMS Daniel; COHN William; PARNIS Steven; GREATREX Nicholas; KURITA Nobuyuki; MASUZAWA Toru
第41回人工心臓と補助循環懇話会学術集会, 01 Feb. 2013

乳児用人工心臓への応用を目指した5自由度制御型磁気浮上モータの開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第41回人工心臓と補助循環懇話会学術集会, 01 Feb. 2013

薄型補助人工心臓に用いる2軸制御型磁気浮上ポンプの開発　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第41回人工心臓と補助循環懇話会学術集会, 01 Feb. 2013

磁気浮上全人工心臓の流量バランス制御　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 西村宣彦; TIMMS Daniel
第41回人工心臓と補助循環懇話会学術集会, 01 Feb. 2013

小児用人工心臓のための小型磁気浮上モータの開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第25回バイオエンジニアリング講演会, 09 Jan. 2013

小型補助人工心臓のためのハイブリッド軸受の開発　　　　　　　　　　　　　　　
床井宏行; 増澤徹; ニコラス グレイトレックス; ウーリッヒ スタインセイファー
第25回バイオエンジニアリング講演会, 09 Jan. 2013

循環系シミュレータにおける血管コンプライアンスと血圧波形との関係の検討　　　　　　　　　　　　　　　
須田佳裕; 増澤徹; 黒崎亘
第25回バイオエンジニアリング講演会, 09 Jan. 2013

弾性ヒンジ型ナノ振動印加装置の研究開発　　　　　　　　　　　　　　　
服部圭介; 増澤徹; 木村孝之; 古山昭
第25回バイオエンジニアリング講演会, 09 Jan. 2013

磁気浮上型全人工心臓のCFD解析　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 西村宣彦; ティムスダニエル
第50回日本人工臓器学会大会, 22 Nov. 2012

複合低エネルギーを用いた組織接合法のin vivo評価　　　　　　　　　　　　　　　
橋本英子; 増澤徹; 尾関和秀; 丸岡寛明; 青代敏行; 樋上哲哉; 舩本誠一; 岸田晶夫; 木村剛
第50回日本人工臓器学会大会, 22 Nov. 2012

乳児用人工心臓のための5自由度制御型磁気浮上モータ　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第50回日本人工臓器学会大会, 22 Nov. 2012

これからの定常流ポンプ研究開発 新しい循環器病治療方法への対応　　　　　　　　　　　　　　　
増澤徹; 西村隆; 許俊鋭; 巽英介; Daniel L Timms
日本定常流ポンプ研究会2012, 22 Nov. 2012, 日本定常流ポンプ研究会

シングル磁気浮上モータ方式全人工心臓の開発　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; Daniel L Timms
第21回MAGDAコンファレンス, 21 Nov. 2012

IPM型5軸制御セルフベアリングモータのコギングトルク低減に関する研究　　　　　　　　　　　　　　　
佐藤心平; 松田健一; 近藤良; 増澤徹
第21回MAGDAコンファレンス, 21 Nov. 2012

薄型補助人工心臓のための2軸制御磁気浮上ポンプの開発　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第21回MAGDAコンファレンス, 21 Nov. 2012

スパッタリング法を用いたSr固溶HA薄膜の作製と骨芽細胞による評価　　　　　　　　　　　　　　　
星野智大; 尾関和秀; 後藤哲哉; 増澤徹; 青木秀希
生活生命支援医療福祉工学系学会連合大会2012, 02 Nov. 2012

せん断流れ場における血液接触材料の表面粗さが溶血量増加に及ぼす定量評価　　　　　　　　　　　　　　　
丸山修; 伊藤大輝; 西田正浩; 山根隆志; 松田健一; 足立吉數; 増澤徹
生活生命支援医療福祉工学系学会連合大会2012, 02 Nov. 2012

磁気浮上全人工心臓の研究開発　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; ダニエル・ティムス
生活生命支援医療福祉工学系学会連合大会2012, 02 Nov. 2012

磁気浮上全人工心臓のポンプ内部圧力分布解明のためのCFD解析　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 西村宣彦; ダニエル・ティムス
生活生命支援医療福祉工学系学会連合大会2012, 02 Nov. 2012

低エネルギ生体融着デバイスの開発－圧力測定機構の付加－　　　　　　　　　　　　　　　
丸岡寛明; 増澤徹; 橋本英子; 青代敏行; 岸田晶夫; 舩本誠一; 樋上哲哉
生活生命支援医療福祉工学系学会連合大会2012, 02 Nov. 2012

Novel Long Term Ventricular Assist Device for Mild Heart Disease Patients　　　　　　　　　　　　　　　
27)Masuzawa T; Ukita K; Onuma H; Nishimura T; Kyo S
XXXIX Annual ESAO Congress, 29 Sep. 2012, ESAO

CFD Analysis for Maglev Total Artificial Heart　　　　　　　　　　　　　　　
Akiko Ota; Toru Masuzawa; Nobuhiko Nishimura; Yusuke Sakata; Daniel L Timms
20th Congress of the International Society for Rotary Blood Pumps, 21 Sep. 2012, the International Society for Rotary Blood Pumps

Levitated Bearings Technology for RBPs: Challenge or Perspective?　　　　　　　　　　　　　　　
25)Toru Masuzawa; Daniel L Timms
20th Congress of the International Society for Rotary Blood Pumps, 20 Sep. 2012, the International Society for Rotary Blood Pumps, [Invited]

新しい人工心臓装着支援技術に関する研究　　　　　　　　　　　　　　　
床井宏行; 増澤徹; 橋本英子; 尾関和秀; 青代敏行; 岸田晶夫; 樋上哲哉; 巽英介
第20回茨城講演会, 24 Aug. 2012

単一磁気浮上モータを用いた全置換型人工心臓の研究開発　　　　　　　　　　　　　　　
坂田佑介; 増澤徹; 西村宣彦; Daniel L Timms
第20回茨城講演会, 24 Aug. 2012

心機能回復のための磁気浮上型血液ポンプの研究開発　　　　　　　　　　　　　　　
山口聡史; 増澤徹; 山田悠; 大森正芳; 前田裕之; 西村隆; 許俊鋭
第20回茨城講演会, 24 Aug. 2012

小型・高性能アウターロータ型5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
平根龍也; 松田健一; 近藤良; 増澤徹
第20回茨城講演会, 24 Aug. 2012

ホモポーラ型ハイブリッド5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
玉置将也; 松田健一; 岡田養二; 近藤良; 増澤徹
第20回茨城講演会, 24 Aug. 2012

スパッタリング法によるストロンチウム固溶HA薄膜の作製と物性評価　　　　　　　　　　　　　　　
星野智大; 尾関和秀; 後藤哲哉; 増澤徹; 青木秀希
第20回茨城講演会, 24 Aug. 2012

磁性ビーズ細胞励振系およびナノ振動計測系の研究開発　　　　　　　　　　　　　　　
服部圭介; 増澤徹; 長真啓; 林照剛
第20回茨城講演会, 24 Aug. 2012

二重円筒型レオメーターを使用したせん断流れ場における表面粗さが溶血に与える影響　　　　　　　　　　　　　　　
丸山修; 伊藤大輝; 西田正浩; 山根隆志; 松田健一; 足立吉數; 増澤徹
第20回茨城講演会, 24 Aug. 2012

5-DOF control double stator otor for paediatric ventricular assist device　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Eisuke Tatsumi
13th international Symposium on Magnetic Bearings(ISMB13), 06 Aug. 2012

人工心臓用ラジアル型磁気浮上モータのステータ突極形状の検討　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹
第24回「電磁力関連のダイナミクス」シンポジウム, 16 May 2012

新しい人工心臓装着支援装置に関する研究　　　　　　　　　　　　　　　
床井宏行; 増澤徹; 青代敏行; 橋本英子; 尾関和秀; 岸田晶夫; 樋上哲哉; 巽英介
第24回「電磁力関連のダイナミクス」シンポジウム, 16 May 2012

ホモポーラ型ハイブリッド5軸制御セルフベアリングモータの提案　　　　　　　　　　　　　　　
松田健一; 玉置将也; 岡田養二; 近藤良; 増澤徹
第24回「電磁力関連のダイナミクス」シンポジウム, 16 May 2012

災害と補助人工心臓在宅治療　　　　　　　　　　　　　　　
増澤徹
第51回日本生体医工学会大会, 10 May 2012

複合低エネルギを用いた鉗子型組織接合装置の開発　　　　　　　　　　　　　　　
丸岡寛明; 増澤徹; 青代敏行; 尾関和秀; 木村剛; 岸田晶夫; 船本誠一; 樋上哲哉
第51回日本生体医工学会大会, 10 May 2012

小型磁気浮上摩擦血液ポンプの開発　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

オンチップ細胞機能制御のための圧電駆動型マイクロ細胞培養デバイスの開発－器械的ナノ振動刺激の付与による細胞接着の評価－　　　　　　　　　　　　　　　
山田侑平; 梅垣彦希; 川島貴弘; 永井萌土; 柴田隆行; 増澤徹; 木村剛; 岸田晶夫
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

弾性損失発熱を利用した生体接着装置の開発　　　　　　　　　　　　　　　
笠原康佑; 南広祐; 木村剛; 清水繁; 青代敏行; 増澤徹; 岸田晶夫
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

生体組織融着技術を用いた血管吻合装置の開発－加熱性能の評価－　　　　　　　　　　　　　　　
橋本一生; 柴建次; 岸田晶夫; 尾関和秀; 増澤徹
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

磁気浮上モータを用いた全置換型人工心臓のポンプ性能　　　　　　　　　　　　　　　
坂田佑介; 増澤徹; 西村宣彦; Daniel L Timms
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

心臓治療用血液ポンプのモータ効率化と溶血性能の検討　　　　　　　　　　　　　　　
山口聡史; 増澤徹; 山田悠; 大森正芳; 前田裕之; 西村隆; 許俊鋭
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

磁気ビーズ細胞励振系およびナノ振動計測系の開発　　　　　　　　　　　　　　　
服部圭介; 増澤徹; 長真啓; 林照剛
第21回ライフサポート学会フロンティア講演会, 03 Mar. 2012, ライフサポート学会

心臓治療用磁気浮上血液ポンプの溶血性能評価　　　　　　　　　　　　　　　
山田悠; 増澤徹; 大森正芳; 前田裕之; 西村隆; 許俊鋭
第40回人工心臓と補助循環懇話会, 17 Feb. 2012

小型非接触摩擦血液ポンプの研究開発　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第40回人工心臓と補助循環懇話会, 17 Feb. 2012

磁気浮上全人工心臓のポンプ性能　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; ダニエルティムズ
第40回人工心臓と補助循環懇話会, 17 Feb. 2012

用途別に分化する磁気浮上型血液ポンプ　　　　　　　　　　　　　　　
増澤徹; 巽英介; 西村隆; 許俊鋭
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

磁気浮上小型摩擦血液ポンプの研究開発　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

動圧軸受血液ポンプのための傾き制御用磁気軸受の研究開発　　　　　　　　　　　　　　　
須田佳裕; 増澤徹; 一ノ瀬高紀; ティムス ダニエル; ウーリッヒ スタインセイファー
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

乳児用人工心臓用小型遠心ポンプの設計と磁気浮上系の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

心機能の回復を目的とした磁気浮上型治療用血液ポンプの研究開発　　　　　　　　　　　　　　　
山田悠; 増澤徹; 大森正芳; 前田裕之; 西村隆; 許俊鋭
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

磁気浮上型全人工心臓の開発　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; ティムス ダニエル
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

複合低エネルギを用いた生体組織技術の開発　　　　　　　　　　　　　　　
丸岡寛明; 増澤徹; 青代敏行; 尾関和秀; 岸田晶夫; 樋上哲哉; 加藤綾子
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

完全人工心臓用カスケードポンプ（ACCELPUMP）の左心用ポンプの評価　　　　　　　　　　　　　　　
福長一義; 阿部祐輔; 山家智之; 巽英介; 増澤徹; 山根隆志; 妙中義之; 井街宏; 舟久保昭夫; 福井康裕
第49回日本人工臓器学会大会, 25 Nov. 2011, 日本人工臓器学会

両心室補助人工心臓への適用を目的としたアキシャル磁気浮上モータの浮上回転特性　　　　　　　　　　　　　　　
栗田伸幸; 石川赴夫; 手塚孝幸; 増澤徹; ダニエル ティムズ
第54回自動制御連合講演会, 19 Nov. 2011

人工心臓用磁気浮上モータにおけるロータ変位の影響　　　　　　　　　　　　　　　
小沼弘幸; 浮田啓悟; 増澤徹
第54回自動制御連合講演会, 19 Nov. 2011

複合低エネルギを用いた鉗子型接合装置の加熱制御　　　　　　　　　　　　　　　
青代敏行; 増澤徹; 丸岡寛明; 尾関和秀; 加藤綾子; 樋上哲哉; 岸田晶夫
第54回自動制御連合講演会, 19 Nov. 2011

A radial type self-bearing motor for small maglev regenerative blood pump　　　　　　　　　　　　　　　
Keigo Ukita; Toru Masuzawa; Hiroyuki Onuma; Takashi Nishimura; Shunei Kyo
The 20th MAGDA COnference in Pacific Asia, 14 Nov. 2011, 日本AEM学会

Development of Lorentz force type tilt control motor for rotary blood pumps　　　　　　　　　　　　　　　
Takannori Ichinose; Toru Masuzawa; Ulrich Steinseifer; Daniel Timms
The 20th MAGDA COnference in Pacific Asia, 14 Nov. 2011, 日本AEM学会

Miniaturized axial gap maglev motor with vector control for pediatric artificial hear　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Eisuke Tatsumi
The 20th MAGDA COnference in Pacific Asia, 14 Nov. 2011, 日本AEM学会

BiVACORⓇ-A Magnetically levited biventricular artificial heart　　　　　　　　　　　　　　　
Daniel Timms; Nobuyuki Kurita; Nicholas Greatrex; Toru Masuzawa
The 20th MAGDA COnference in Pacific Asia, 14 Nov. 2011, 日本AEM学会

誘導加熱を用いた手術用生体融着システムの検討　　　　　　　　　　　　　　　
秋山直矢; 柴建次; 岸田昌夫; 尾関和秀; 増澤徹
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

新規せん断負荷装置を使用したせん断流れ場における高粘度ウシ血液の溶血特性　　　　　　　　　　　　　　　
丸山修; 玉置将也; 西田正浩; 山根隆志; 松田健一; 足立吉數; 増澤徹
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

磁気浮上モータを用いた全人工心臓のポンプ性能　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; Daniel L Timms
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

心機能回復のための治療用血液ポンプの研究開発　　　　　　　　　　　　　　　
山田悠; 増澤徹; 西村隆; 許俊鋭
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

人工心臓の性能評価のための循環系シミュレータの研究開発　　　　　　　　　　　　　　　
須田佳裕; 増澤徹; 黒崎亘
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

複合低エネルギによる鉗子型融着デバイスの温度制御技術　　　　　　　　　　　　　　　
丸岡寛明; 増澤徹; 青代敏行; 尾関和秀; 加藤綾子; 岸田昌夫; 樋上哲哉
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

ストロンチウムアパタイト薄膜の作製とその細胞接着性評価　　　　　　　　　　　　　　　
星野智大; 尾関和秀; 後藤哲哉; 増澤徹; 青木秀希
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

微小振動下における細胞接着過程の検討　　　　　　　　　　　　　　　
木村剛; 伊藤由樹子; 南広祐; 加藤綾子; 増澤徹; 岸田昌夫
生活生命支援医療福祉工学系連合大会2011, 03 Nov. 2011, ライフサポート学会

スパッタリング法を用いたストロンチウムアパタイト薄膜の作製とその細胞応答性　　　　　　　　　　　　　　　
星野智大; 尾関和秀; 後藤哲哉; 増澤徹; 青木秀希
第19回茨城講演会, 26 Aug. 2011

複合低エネルギによる金属と生体組織の接合技術　　　　　　　　　　　　　　　
丸岡寛明; 増澤徹; 青代敏行; 尾関和秀; 加藤綾子; 岸田昌夫; 樋上哲哉
第19回茨城講演会, 26 Aug. 2011

IPM型5軸制御セルフベアリングモータに関する研究　　　　　　　　　　　　　　　
佐藤心平; 松田健一; 近藤良; 増澤徹
第19回茨城講演会, 26 Aug. 2011

補助人工心臓用アキシャル型磁気軸受の最適化に関する研究　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; 寺山昌幸; Daniel L Timms
第19回茨城講演会, 26 Aug. 2011

動圧軸受血液ポンプのための傾き制御機構の研究開発　　　　　　　　　　　　　　　
須田佳裕; 増澤徹; 一ノ瀬高紀; ダニエル・ティムズ; ウーリッヒ・スタインセイファー
第19回茨城講演会, 26 Aug. 2011

循環補助用小型磁気浮上摩擦血液ポンプの研究開発　　　　　　　　　　　　　　　
山田悠; 増澤徹; 浮田啓悟; 西村隆; 許俊鋭
第19回茨城講演会, 26 Aug. 2011

コーン・シリンダー型レオメーターを使用したせん断流れ場におけるウシ血液の溶血特性、　　　　　　　　　　　　　　　
丸山修; 玉置将也; 西田正浩; 山根隆志; 松田健一; 足立吉數; 増澤徹
第19回茨城講演会, 26 Aug. 2011

誘導加熱を用いた手術用生体融着システムの検討-周波数変化における温度特性-　　　　　　　　　　　　　　　
秋山直矢; 柴建次; 岸田昌夫; 尾関和秀; 増澤徹
第19回茨城講演会, 26 Aug. 2011

小型ローレンツ型磁気浮上モータのサーボモータ制御　　　　　　　　　　　　　　　
岡田養二; 三好理文; 増澤徹; 榎園正人
第23回「電磁力関連のダイナミクス」シンポジウム, 18 May 2011

人工心臓のための12突極ラジアル型磁気浮上モータにおける最適極数の検討　　　　　　　　　　　　　　　
小沼弘幸; 浮田啓悟; 増澤徹
第23回「電磁力関連のダイナミクス」シンポジウム, 18 May 2011

全人工心臓用磁気浮上モータの磁気支持性能　　　　　　　　　　　　　　　
増澤徹; 寺山昌幸; ダニエル L ティムス
第23回「電磁力関連のダイナミクス」シンポジウム, 18 May 2011

医療用高分子材料の表面特性と接着　　　　　　　　　　　　　　　
中村奈緒子; 南広祐; 木村剛; 増澤徹; 岸田昌夫
第50回日本生体医工学会大会, 29 Apr. 2011

微小振動を用いた小型組織融着装置の開発　　　　　　　　　　　　　　　
笠原康佑; 南広祐; 木村剛; 清水繁; 青代敏行; 増澤徹; 岸田昌夫
第50回日本生体医工学会大会, 29 Apr. 2011

乳児用人工心臓専用磁気浮上モータのベクトル制御　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第50回日本生体医工学会大会, 29 Apr. 2011

磁気浮上型治療用血液ポンプの開発　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 西村隆; 許俊鋭
第50回日本生体医工学会大会, 29 Apr. 2011

人工心臓のための磁気浮上技術　　　　　　　　　　　　　　　
増澤徹
第50回日本生体医工学会大会, 29 Apr. 2011

磁気浮上型両心補助用人工心臓の研究開発　　　　　　　　　　　　　　　
寺山昌幸; 増澤徹; 西村宣彦; ダニエル L ティムス
第50回日本生体医工学会大会, 29 Apr. 2011

小型磁気浮上摩擦血液ポンプの研究開発　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第50回日本生体医工学会大会, 29 Apr. 2011

動圧血液ポンプのための傾き制御モータの開発　　　　　　　　　　　　　　　
一ノ瀬型の理; 増澤徹; ダニエル ティムス; ウーリッヒ スタインセイファー
第50回日本生体医工学会大会, 29 Apr. 2011

複合低エネルギによる鉗子型組織接合装置の開発　　　　　　　　　　　　　　　
青代敏行; 増澤徹; 猪野学; 尾関和秀; 加藤綾子; 岸田昌夫; 木村剛; 樋上哲哉
第50回日本生体医工学会大会, 29 Apr. 2011

動圧軸受血液ポンプのための傾き制御モータの提案　　　　　　　　　　　　　　　
一ノ瀬高紀; 増澤徹; Ulrich Steinseif; Daniel L Timms
第39回人工心臓と補助循環懇話会, 05 Mar. 2011

循環補助用超小型非接触摩擦ポンプの研究開発　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
第39回人工心臓と補助循環懇話会, 05 Mar. 2011

ベクトル制御を用いた乳児用小型磁気浮上人工心臓の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

スパッタリング法を用いたストロンチウムアパタイト薄膜の作製と物性評価　　　　　　　　　　　　　　　
星野智大; 尾関和秀; 増澤徹; 青木秀希
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

循環補助用小型磁気浮上摩擦ポンプの研究開発　　　　　　　　　　　　　　　
山田悠; 増澤徹; 浮田啓悟; 小沼弘幸; 西村隆; 許俊鋭
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

人工心臓用アキシャル型磁気軸受の最適化に関する研究　　　　　　　　　　　　　　　
西村宣彦; 増澤徹; 寺山昌幸; Daniel L Timms
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

動圧軸受血液ポンプのための小型傾き制御用磁気軸受の提案　　　　　　　　　　　　　　　
須田佳裕; 増澤徹; 一ノ瀬隆紀; Ulrich Steinseifer; Daniel L Timms
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

誘導加熱を用いた手術用生体融着システム　　　　　　　　　　　　　　　
秋山直矢; 柴建次; 尾関和秀; 増澤徹
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

微小振動を用いた小型組織融着装置の開発　　　　　　　　　　　　　　　
笠原康佑; 南広祐; 木村剛; 清水繁; 青代敏行; 増澤徹; 岸田昌夫
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

複合低エネルギを用いた金属と生体組織の接合技術　　　　　　　　　　　　　　　
丸岡寛明; 増澤徹; 青代敏行; 尾関和秀; 加藤綾子; 岸田昌夫; 樋上哲哉
第20回ライフサポート学会フロンティア講演会, 05 Mar. 2011

人工心臓のための磁気浮上モータの設計　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 小沼弘幸; 西村隆; 許俊鋭
日本生体医工学会関東支部若手研究者発表会2010, 27 Nov. 2010

低エネルギ複合による鉗子型融着デバイスの開発　　　　　　　　　　　　　　　
猪野学; 増澤徹; 青代敏行; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲也; 加藤綾子
日本生体医工学会関東支部若手研究者発表会2010, 27 Nov. 2010

乳児用人工心臓用ダブルステータ型磁気浮上モータの開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第19回MAGDAコンファレンスin 札幌, 22 Nov. 2010

治療用人工心臓のためのアキシャル型磁気浮上モータの開発　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 西村隆; 許俊鋭
第19回MAGDAコンファレンスin 札幌, 22 Nov. 2010

両心補助および全人工心臓を目指した磁気浮上人工心臓BiVACOR　　　　　　　　　　　　　　　
増澤徹
第48回日本人工臓器学会大会, 18 Nov. 2010

複合低エネルギによる金属と生体組織接合技術の開発　　　　　　　　　　　　　　　
青代敏行; 増澤徹; 猪野学; 尾関和秀; 加藤綾子; 岸田晶夫; 木村剛; 樋上哲也
第48回日本人工臓器学会大会, 18 Nov. 2010

両心補助用人工心臓のためのインペラ位置可変磁気浮上モータの開発　　　　　　　　　　　　　　　
寺山昌幸; 増澤徹; Dniel L Timms
第48回日本人工臓器学会大会, 18 Nov. 2010

自己心機能回復を目的とした磁気浮上型人工心臓の開発　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 浮田啓悟; 西村隆; 許俊鋭
第48回日本人工臓器学会大会, 18 Nov. 2010

ダブルステータ型磁気浮上モータを用いた乳児用人工心臓の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
日本定常流ポンプ研究会2010, 18 Nov. 2010

磁気浮上人工心臓における浮上インペラの変動要因の検討　　　　　　　　　　　　　　　
小沼弘幸; 浮田啓悟; 増澤徹
第53回自動制御連合講演会, 05 Nov. 2010

オンチップ細胞機能制御のための圧電駆動型マイクロ細胞培養デバイスの開発 －細胞導入の効率化と細胞実験の基礎的検討－　　　　　　　　　　　　　　　
山田侑平; 大竹英明; 柴田隆行; 川島貴弘; 永井萌土; 増澤徹; 木村剛; 岸田晶夫
第53回自動制御連合講演会, 05 Nov. 2010

弾性ヒンジ機構を用いたナノ振動細胞加振装置の開発　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 青代敏行; 木村孝之; 岸田晶夫; 伊藤由樹子; 木村剛
生活生命支援医療福祉工学系連合大会2010, 18 Sep. 2010

微小振動融着法を用いた高分子コラーゲン間の接着　　　　　　　　　　　　　　　
笠原康佑; 山本健二; 舩本誠一; 南広祐; 木村剛; 清水繁; 青代敏行; 増澤徹; 岸田晶夫
生活生命支援医療福祉工学系連合大会2010, 18 Sep. 2010

低エネルギ生体融着デバイスの発熱機構の開発　　　　　　　　　　　　　　　
猪野学; 増澤徹; 青代敏行; 尾関和秀; 加藤綾子; 岸田晶夫; 樋上哲哉
生活生命支援医療福祉工学系連合大会2010, 18 Sep. 2010

せん断流れ場における表面粗さに基づく溶血特性－高粘度血液を使用した実験－　　　　　　　　　　　　　　　
丸山修; 江尻賢治; 西田正浩; 山根隆志; 永井文秀; 足立吉數; 増澤徹
生活生命支援医療福祉工学系連合大会2010, 18 Sep. 2010

乳児用小型磁気浮上人工心臓の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
生活生命支援医療福祉工学系連合大会2010, 18 Sep. 2010

乳児用磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
一ノ瀬高紀; 長真啓; 増澤徹; 巽英介
茨城講演会, 27 Aug. 2010

急性心不全を対象とした磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
浮田啓悟; 北郷将史; 増澤徹; 西村隆; 許俊鋭
茨城講演会, 27 Aug. 2010

Miniaturized magnetically levitated motor for pediatric artificial heart　　　　　　　　　　　　　　　
Masahiro Osa; Toru Masuzawa; Eisuke Tatsumi
12th International Symposium on Magnetic Bearings, 24 Aug. 2010

心機能代替プロジェクト「小型な人工心臓が心臓を補助する」　　　　　　　　　　　　　　　
増澤徹
第49回日本生体医工学会大会, 25 Jun. 2010

Magnetically levitated therapeutic artificial heart　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 浮田啓悟; 西村隆; 許俊鋭
第49回日本生体医工学会大会, 25 Jun. 2010

Current development status of artificial heart　　　　　　　　　　　　　　　
増澤徹
第49回日本生体医工学会大会, 25 Jun. 2010

Adhesion technology using integrated low level energies　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 青代敏行; 河野貴宏; 岸田晶夫; 木村剛; 樋上哲哉
第49回日本生体医工学会大会, 25 Jun. 2010

Nano vibration cell stimulus device　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 青代敏行; 小林亜美子; 木村孝之; 岸田晶夫; 伊藤由樹子
第49回日本生体医工学会大会, 25 Jun. 2010

Development of cell culture microdevice integrated with piezoelectric thin film actuator for on-chip regulation of cell functions　　　　　　　　　　　　　　　
川島貴弘; 松澤勇太; 山田侑平; 柴田隆行; 増澤徹; 木村剛; 岸田晶夫
第49回日本生体医工学会大会, 25 Jun. 2010

IPM型5軸制御セルフベアリングモータの提案　　　　　　　　　　　　　　　
松田健一; Mohd Syawqei; 近藤良; 増澤徹
第22回「電磁力関連のダイナミクス」シンポジウム, 19 May 2010

低エネルギ複合による生体組織接合デバイスの開発　　　　　　　　　　　　　　　
青代敏行; 増澤徹; 河野貴宏; 岸田晶夫; 樋上哲哉; 加藤綾子
第22回「電磁力関連のダイナミクス」シンポジウム, 19 May 2010

シングルモータ方式磁気浮上型両心補助人工心臓の研究開発　　　　　　　　　　　　　　　
寺山昌幸; 増澤徹; ダニエル L ティムス
第22回「電磁力関連のダイナミクス」シンポジウム, 19 May 2010

斜流式磁気浮上人工心臓に関する研究　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
第19回ライフサポート学会フロンティア講演会, 06 Mar. 2010

急性心不全患者を対象とした治療用人工心臓の研究開発　　　　　　　　　　　　　　　
浮田啓悟; 増澤徹; 北郷将史; 西村隆; 許俊鋭
第19回ライフサポート学会フロンティア講演会, 06 Mar. 2010

乳幼児用磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
一ノ瀬高紀; 増澤徹; 長真啓; 巽英介
第19回ライフサポート学会フロンティア講演会, 06 Mar. 2010

オンチップ細胞機能制御のための圧電駆動型マイクロ細胞培養デバイスの開発　　　　　　　　　　　　　　　
松澤勇太; 山田侑平; 柴田隆行; 川島貴弘; 増澤徹; 木村剛; 岸田晶夫
第19回ライフサポート学会フロンティア講演会, 06 Mar. 2010

乳児対象小型磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第38回人工心臓と補助循環懇話会, 26 Feb. 2010

磁気浮上型両心補助用人工心臓の研究開発　　　　　　　　　　　　　　　
寺山昌幸; 増澤徹; 北郷将史; Daniel L Timms
第38回人工心臓と補助循環懇話会, 26 Feb. 2010

人工心臓開発の要素技術の現状と展望 磁気浮上技術　　　　　　　　　　　　　　　
増澤徹
第38回人工心臓と補助循環懇話会, 26 Feb. 2010, [Invited]

小型人工心臓のための全軸制御型磁気浮上斜流ポンプ　　　　　　　　　　　　　　　
増澤徹; 松井寿定; 巽英介
第22回代用臓器・再生医学研究会, 23 Jan. 2010

Magnetic suspension technology for 3rd generation blood pumps　　　　　　　　　　　　　　　
Toru Masuzawa
KNU & KAOC international symposium, 27 Nov. 2009, Kangwon National University Artificial Heart Center, Korea University Korea Artificial Organ Center

磁束集束ローレンツ型磁気浮上モータの研究　　　　　　　　　　　　　　　
岡田養二; 北郷将史; 伊佐川晃平; 増澤徹; 榎園正人
第18回MAGDAコンファレンスin東京, 19 Nov. 2009

両心補助人工心臓BiVACOR Bi-VAD用磁気浮上モータ　　　　　　　　　　　　　　　
増澤徹; 佐々木瑛介; ダニエル L ティムス
第18回MAGDAコンファレンスin東京, 19 Nov. 2009

一体型アキシャル磁気浮上モータを用いた両心補助／全人工心臓BiVACOR　　　　　　　　　　　　　　　
増澤徹; Daniel Timms
日本定常流ポンプ研究会2009, 12 Nov. 2009

高耐久性、高生体適合性を実現する磁気浮上技術　　　　　　　　　　　　　　　
増澤徹
第47回日本人工臓器学会大会, 12 Nov. 2009, [Invited]

斜流式人工心臓の磁気浮上インペラに作用する流体力の検討　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
第47回日本人工臓器学会大会, 12 Nov. 2009

小型両心補助用磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 松井寿定; 寺山昌幸; ティムズ ダニエル
第47回日本人工臓器学会大会, 12 Nov. 2009

新生児・乳児用小型人工心臓のための磁気浮上系の開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
第47回日本人工臓器学会大会, 12 Nov. 2009

両心補助用人工心臓のための一体型アキシャル磁気浮上モータの開発　　　　　　　　　　　　　　　
北郷将史; 増澤徹; 佐々木瑛祐; Daniel Timms
第7回生活支援工学系学会連合大会, 24 Sep. 2009

食品容器を目的とした光触媒／DLC膜の消臭性評価　　　　　　　　　　　　　　　
尾関和秀; 大石信洋; 宮沢真吾; 平栗健二; 増澤徹
第7回生活支援工学系学会連合大会, 24 Sep. 2009

弾性ヒンジを用いたナノ振動細胞加振装置の開発　　　　　　　　　　　　　　　
小林亜美子; 増澤徹; 加藤綾子; 木村孝之; 木村剛; 岸田晶夫
第7回生活支援工学系学会連合大会, 24 Sep. 2009

微小振動融着法による高分子材料－生体組織間の接着に関する研究　　　　　　　　　　　　　　　
山本健二; 木村剛; 南広祐; 加藤綾子; 清水繁; 樋上哲哉; 増澤徹; 岸田晶夫
第7回生活支援工学系学会連合大会, 24 Sep. 2009

せん断流れ場において表面粗さに基づく溶血特性－せん断応力の増加と溶血量増加の相関　　　　　　　　　　　　　　　
丸山修; 阿部純也; 西田正浩; 山根隆志; 大島郁也; 永井文秀; 足立吉數; 増澤徹
第7回生活支援工学系学会連合大会, 24 Sep. 2009

オンチップ細胞機能制御のための圧電駆動型マイクロ細胞培養デバイスの開発　　　　　　　　　　　　　　　
松澤勇太; 柴田隆行; 川島貴弘; 増澤徹; 木村剛; 岸田晶夫
第7回生活支援工学系学会連合大会, 24 Sep. 2009

高性能で小型化が可能な5軸制御セルフベアリングモータの開発　　　　　　　　　　　　　　　
松田健一; 石川達也; 近藤良; 増澤徹
日本機械学会Dynamics and Design Conference 2009, 03 Sep. 2009

磁束集束ローレンツ浮上モータの提案　　　　　　　　　　　　　　　
岡田養二; 北郷将史; 増澤徹; 榎園正人
日本機械学会Dynamics and Design Conference 2009, 03 Sep. 2009

CVD法により作成されたDLC膜の有機分子の吸着特性評価　　　　　　　　　　　　　　　
宮澤真吾; 尾関和秀; 平栗健二; 増澤徹
茨城講演会, Aug. 2009

歯科インプラント実習を目的としたアパタイト／レジン模擬骨に関する研究　　　　　　　　　　　　　　　
稲垣尭久; 尾関和秀; 増澤徹; 青木秀希; 宇佐美諒真
茨城講演会, Aug. 2009

新生児・乳幼児用人工心臓のための磁気浮上モータの開発　　　　　　　　　　　　　　　
長真啓; 増澤徹; 巽英介
茨城講演会, Aug. 2009

人工心臓適用を目指した5軸制御セルフベアリングモータの小型化に関する研究　　　　　　　　　　　　　　　
寺山昌幸; 松田健一; 増澤徹; 近藤良
茨城講演会, Aug. 2009

粗さを付加したときの表面付近のせん断応力場に関する数値解析　　　　　　　　　　　　　　　
西田正浩; 丸山修; 山根隆志; 増澤徹; 永井文秀
茨城講演会, Aug. 2009

血液のせん断流れ場において金属材料表面粗さが溶血に及ぼす影響　　　　　　　　　　　　　　　
丸山修; 西田正浩; 山根隆志; 永井文秀; 足立吉數; 増澤徹
茨城講演会, Aug. 2009

4軸制御型磁気軸受を用いた磁気浮上クリーンポンプの研究開発　　　　　　　　　　　　　　　
黒須寛秋; 増澤徹; 加藤綾子; 小沼弘幸; 柿原功一
日本AEM学会, Jun. 2009

両心室補助人工心臓への応用を目的としたアキシャル磁気浮上モータの開発　　　　　　　　　　　　　　　
栗田伸幸; Daniel Timms; Nicholas Greatrex; 増澤徹
第21回「電磁力関連のダイナミクス」シンポジウム, 20 May 2009

5軸制御セルフベアリングモータの小型化に関する研究　　　　　　　　　　　　　　　
松田健一; 寺山昌幸; 増澤徹; 近藤良
第21回「電磁力関連のダイナミクス」シンポジウム, 20 May 2009

複合低エネルギ組織融着技術の研究開発　　　　　　　　　　　　　　　
河野貴宏; 増澤徹; 加藤綾子; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉
第21回「電磁力関連のダイナミクス」シンポジウム, 20 May 2009

斜流式人工心臓のための磁気浮上モータシステムの開発　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
第21回「電磁力関連のダイナミクス」シンポジウム, 20 May 2009

医用アクチュエータの最新の話題、電磁駆動アクチュエータ（回転）：磁気浮上モータ　　　　　　　　　　　　　　　
増澤徹
第48回日本生体医工学会大会, 23 Apr. 2009, [Invited]

顕微鏡に設置可能なナノ振動細胞刺激装置の開発　　　　　　　　　　　　　　　
小林亜美子; 増澤徹; 加藤綾子; 木村孝之; 岸田晶夫
第48回日本生体医工学会大会, 23 Apr. 2009

微笑振動付加による種々の細胞の基材への接着と増殖の効果　　　　　　　　　　　　　　　
吾郷友亮; 伊藤由樹子; 木村剛; 南広祐; 加藤綾子; 増澤徹; 岸田晶夫
第48回日本生体医工学会大会, 23 Apr. 2009

ナノ振動融着法による高分子材料‐生体組織間の接着に関する研究　　　　　　　　　　　　　　　
山本健二; 宮廻寛; 木村剛; 南広祐; 加藤綾子; 栗田公夫; 樋上哲哉; 増澤徹; 岸田晶夫
第48回日本生体医工学会大会, 23 Apr. 2009

複合低エネルギ－を利用した組織融着に関する研究　　　　　　　　　　　　　　　
河野貴宏; 増澤徹; 加藤綾子; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉
第48回日本生体医工学会大会, 23 Apr. 2009

斜流式人工心臓用磁気軸受の開発　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
第48回日本生体医工学会大会, 23 Apr. 2009

フッ素添加DLC膜のタンパク質吸着特性評価　　　　　　　　　　　　　　　
尾関和秀; 平栗健二; 増澤徹
第48回日本生体医工学会大会, 23 Apr. 2009

身体活動度モニタリングスーツによる日常生活活動のエネルギー消費量推定　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 石井博徳; 植野彰規
第48回日本生体医工学会大会, 23 Apr. 2009

培養細胞を対象としたナノ振動加振装置の振動特性解析　　　　　　　　　　　　　　　
小林亜美子; 増澤徹; 加藤綾子; 木村孝之; 岸田晶夫
日本機械学会関東支部第15期総会講演会, 06 Mar. 2009

複合低エネルギを利用した組織融着技術に関する研究　　　　　　　　　　　　　　　
河野貴宏; 増澤徹; 加藤綾子; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉
日本機械学会関東支部第15期総会講演会, 06 Mar. 2009

DT-QOL向上のための技術開発とは？デバイス故障と闘う軸受技術　　　　　　　　　　　　　　　
増澤徹
第37回人工心臓と補助循環懇話会, 27 Feb. 2009, [Invited]

多軸制御型斜流式磁気浮上人工心臓の研究開発　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
第37回人工心臓と補助循環懇話会, 27 Feb. 2009

茨城大学における磁気浮上型人工心臓の研究開発　　　　　　　　　　　　　　　
増澤徹
つくば医工連携フォーラム2009, 14 Jan. 2009

両心補助用人工心臓BIVACOR Bi-VADの開発　　　　　　　　　　　　　　　
増澤徹; 佐々木瑛祐; 栗田伸幸; ダニエル ティムス
日本定常流ポンプ研究会, 27 Nov. 2008

人工内臓から内蔵機器へ－人工臓器“体内埋込技術”の新展開　　　　　　　　　　　　　　　
増澤徹
第46回日本人工臓器学会大会, 27 Nov. 2008

人工心臓の仕組み　　　　　　　　　　　　　　　
増澤徹
第46回日本人工臓器学会大会, 27 Nov. 2008

非定常CFD解析による磁気浮上型遠心ポンプのインペラに働く流体力の推定　　　　　　　　　　　　　　　
増澤徹; 松井寿定; 田中伸厚; 築谷朋典; 銭逸
第46回日本人工臓器学会大会, 27 Nov. 2008

種々の細胞機能に対する機械的ナノ振動刺激の影響に関する検討　　　　　　　　　　　　　　　
伊藤由樹子; 吾郷友亮; 木村剛; 南広祐; 小林亜美子; 加藤綾子; 増澤徹; 岸田晶夫
第46回日本人工臓器学会大会, 27 Nov. 2008

斜流式磁気浮上型人工心臓の開発　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
第46回日本人工臓器学会大会, 27 Nov. 2008

表面粗さを付加した回転せん断負荷装置内の流れと溶血との関係　　　　　　　　　　　　　　　
西田正浩; 丸山修; 山根隆志; 永井文秀; 大島郁也; 増澤徹
第46回日本人工臓器学会大会, 27 Nov. 2008

4軸制御型磁気軸受を用いた磁気浮上クリーンポンプの研究開発　　　　　　　　　　　　　　　
黒須寛秋; 増澤徹; 加藤綾子; 小沼弘幸; 柿原功一
第17回MAGDAコンファレンスin 日立, 20 Nov. 2008

5軸制御型セルフベアリングモータの傾き制御特性　　　　　　　　　　　　　　　
石川達也; 松田健一; 増澤徹; 近藤良
第17回MAGDAコンファレンスin 日立, 20 Nov. 2008

両心補助人工心臓BIVACOR Bi-VADの磁気浮上システムの開発　　　　　　　　　　　　　　　
佐々木瑛祐; 増澤徹; 栗田伸幸
リニアドライブ研究会, Nov. 2008

複合低エネルギ利用による低損傷生体組織融着技術における伝熱特性の影響　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 河野貴宏; 木村孝之; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
第6回生活支援工学系学会連合大会, 17 Sep. 2008

せん断流れ場において表面粗さの大きさとせん断応力が溶血に及ぼす影響　　　　　　　　　　　　　　　
丸山修; 川口雄大; 米谷幸治; 西田正浩; 山根隆志; 永井文秀; 足立吉數; 増澤徹
第6回生活支援工学系学会連合大会, 17 Sep. 2008

表面粗さを付加した回転せん断負荷装置内の流れ解析　　　　　　　　　　　　　　　
西田正浩; 塚越洋之; 川口雄大; 丸山修; 山根隆志; 増澤徹; 永井文秀
第6回生活支援工学系学会連合大会, 17 Sep. 2008

新しい低損傷生体組織融着技術によるステントグラフト融着の評価　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 河野貴宏; 木村孝之; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
第6回生活支援工学系学会連合大会, 17 Sep. 2008

両心補助用人工心臓BIVACOR Bi-VADのための磁気浮上系の開発　　　　　　　　　　　　　　　
増澤徹; 佐々木瑛祐; 栗田伸幸; ダニエル ティムズ
第6回生活支援工学系学会連合大会, 17 Sep. 2008

スパッタHA薄膜の薬剤吸着特性と抗血栓性評価　　　　　　　　　　　　　　　
尾関和秀; 吉原裕貴; 増澤徹
第6回生活支援工学系学会連合大会, 17 Sep. 2008

身体活動度モニタリングスーツによるエネルギー消費量の推定　　　　　　　　　　　　　　　
石井博徳; 増澤徹; 加藤綾子
第6回生活支援工学系学会連合大会, 17 Sep. 2008

Ti・ステンレス基材に対するSi中間層を用いたDLC膜の密着性の研究　　　　　　　　　　　　　　　
佐藤実; 永島勲; 尾関和秀; 増澤徹
茨城講演会, Sep. 2008

斜流式磁気浮上人工心臓用ポンプの研究開発　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 巽英介
茨城講演会, Sep. 2008

表面粗さを付加した回転せん断付加装置内の数値解析　　　　　　　　　　　　　　　
西田正浩; 柳生祥丈; 丸山修; 山根隆志; 増澤徹; 永井文秀; 大島郁也
茨城講演会, Sep. 2008

カテーテル型ステント融着マニピュレータに関する開発　　　　　　　　　　　　　　　
河野貴宏; 増澤徹; 加藤綾子; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
茨城講演会, Sep. 2008

ナノ振動細胞刺激装置の振動特性解析　　　　　　　　　　　　　　　
小林亜美子; 増澤徹; 加藤綾子; 木村孝之; 岸田晶夫; 木村剛
茨城講演会, Sep. 2008

5-DOF controlled self-bearing motor　　　　　　　　　　　　　　　
Tatsuya Ishikawa; Ken-ichi Matsuda; Toru Masuzawa; Ryou Kondo
11th International Symposium on Magnetic Bearings, 26 Aug. 2008

Wide gap magnetic bearing system for a magnetically suspended clean pump　　　　　　　　　　　　　　　
Hiroaki Kurosu; Toru Masuzawa; Ayako Katoh; Kenichi Suzuki
11th International Symposium on Magnetic Bearings, 26 Aug. 2008

Evaluation of a new hybrid magnetic bearing for the bivacor BI-VAD/TAH　　　　　　　　　　　　　　　
Eisuke Sasaki; Toru Masuzawa; Nobuyuki Kurita; Daniel Timms
ASAIO 54th Annual conference, 19 Jun. 2008

扁平型ハイブリッド磁気軸受の最適化設計　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 鈴木健一
第20回「電磁力関連のダイナミクス」シンポジウム, 21 May 2008

複合低エネルギを用いた生体組織と人工物の融着技術の開発　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 尾関秀和; 木村孝之; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
第47回日本生体医工学会大会, 08 May 2008

身体活動度モニタスーツの開発　　　　　　　　　　　　　　　
石井博徳; 増澤徹; 加藤綾子
第47回日本生体医工学会大会, 08 May 2008

カテーテル型ステント融着マニピュレータに関する開発研究　　　　　　　　　　　　　　　
河野貴宏; 増澤徹; 加藤綾子; 濱口崇志; 尾関和秀; 木村孝之; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
人と福祉を支える技術フォーラム2008, 01 Mar. 2008, ライフサポート学会

斜流式人工心臓用ポンプの研究開発　　　　　　　　　　　　　　　
松井寿定; 増澤徹; 太田晶子; 巽英介
人と福祉を支える技術フォーラム2008, 01 Mar. 2008, ライフサポート学会

磁気浮上人工心臓ポンプの非定常CFD解析　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 田中伸厚; 銭逸; 築谷朋典
人と福祉を支える技術フォーラム2008, 01 Mar. 2008, ライフサポート学会

「細胞を対象とした工学研究」の共通概念の構築―機械工学サイドから―　　　　　　　　　　　　　　　
増澤徹
人と福祉を支える技術フォーラム2008, 01 Mar. 2008, ライフサポート学会

ナノ振動細胞刺激装置の開発研究　　　　　　　　　　　　　　　
小林亜美子; 増澤徹; 加藤綾子; 木村孝之; 橋本健児; 岸田晶夫; 木村剛
人と福祉を支える技術フォーラム2008, 01 Mar. 2008, ライフサポート学会

両心補助用人工心臓のためのハイブリッド型磁気軸受の開発　　　　　　　　　　　　　　　
佐々木瑛祐; 増澤徹
第36回人工心臓と補助循環懇話会, Mar. 2008, 東京電機大学理工学部電子情報工学科 福井康裕（世話人）

小型磁気浮上斜流ポンプの研究開発　　　　　　　　　　　　　　　
黒須寛秋; 鈴木健一; 加藤綾子; 増澤徹
第36回人工心臓と補助循環懇話会, Mar. 2008, 東京電機大学理工学部電子情報工学科 福井康裕（世話人）

５軸能動制御型セルフベアリングモータの開発　　　　　　　　　　　　　　　
松田健一; 石川達也; 増澤徹; 近藤良
第16回MAGDAコンファレンスin京都, Nov. 2007, 日本AEM学会

磁気軸受用センサの開発　　　　　　　　　　　　　　　
岡田養二; 石川達也; 増澤徹; 近藤良
第16回MAGDAコンファレンスin京都, Nov. 2007, 日本AEM学会

扁平型ハイブリッド磁気軸受の開発　　　　　　　　　　　　　　　
鈴木健一; 増澤徹
第16回MAGDAコンファレンスin京都, Nov. 2007, 日本AEM学会

ハイブリッド型磁気軸受を用いた磁気浮上型血液ポンプの開発　　　　　　　　　　　　　　　
鈴木健一; 増澤徹
第5回生活支援工学系学会連合大会, Oct. 2007, ライフサポート学会

循環系治療機器の工学的評価に関する研究　　　　　　　　　　　　　　　
石塚健太郎; 増澤徹; 加藤綾子; 岸田晶夫; ダニエルLティムス
第5回生活支援工学系学会連合大会, Oct. 2007, ライフサポート学会

磁気浮上人工心臓ポンプの非定常CFD解析　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 田中伸厚; 銭逸; 築谷朋典
第5回生活支援工学系学会連合大会, Oct. 2007, ライフサポート学会

ナノ振動刺激時における細胞膜近傍の剪断応力解析　　　　　　　　　　　　　　　
橋本健児; 増澤徹; 木村孝之; 加藤綾子; 岸田晶夫; 木村剛
第5回生活支援工学系学会連合大会, Oct. 2007, ライフサポート学会

低エネルギ複合による生体接合技術の開発　　　　　　　　　　　　　　　
濱口崇志; 増澤徹; 加藤綾子; 尾関和秀; 木村孝之; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
第5回生活支援工学系学会連合大会, Oct. 2007, ライフサポート学会

層流せん断流れ場において材料表面粗さが溶血に及ぼす影響　　　　　　　　　　　　　　　
川口雄大; 丸山修; 西田正弘; 山根隆志; 永井文秀; 足立吉數; 増澤徹
第5回生活支援工学系学会連合大会, Oct. 2007, ライフサポート学会

人工心臓のための小型ハイブリッド型磁気軸受　　　　　　　　　　　　　　　
増澤徹; 鈴木健一; 黒須寛秋; 加藤綾子
電気学会研究会, Oct. 2007, 電気学会

健康管理ロボットによる食事摂取量計測に関する基礎的研究　　　　　　　　　　　　　　　
石井博徳; 増澤徹; 加藤綾子
茨城講演会, 28 Sep. 2007, 日本機械学会

循環系シミュレータの開発と磁気浮上型人工心臓の評価　　　　　　　　　　　　　　　
黒須寛秋; 増澤徹; 石塚健太郎; Daniel L Timms
茨城講演会, 28 Sep. 2007, 日本機械学会

ダブルバイアス磁束型磁気浮上血液ポンプの開発　　　　　　　　　　　　　　　
佐々木瑛祐; 増澤徹; 小沼弘幸
茨城講演会, 28 Sep. 2007, 日本機械学会

SPH法と格子法の組み合わせによるメゾスケール血流解析　　　　　　　　　　　　　　　
中村信之; 田中伸厚; 増澤徹
茨城講演会, 28 Sep. 2007, 日本機械学会

人工心臓内の材料表面粗さによるせん断応力と血球破壊に関する研究　　　　　　　　　　　　　　　
川口雄大; 丸山修; 西田正弘; 山根隆志; 永井文秀; 足立吉數; 増澤徹
茨城講演会, 28 Sep. 2007, 日本機械学会

人工心臓の最近の進歩　　　　　　　　　　　　　　　
増澤徹
体外循環と補助循環2007 第23回日本人工臓器学会教育セミナー, Jul. 2007, 日本人工臓器学会

人工心臓用ダブルバイアス磁束型磁気浮上システム　　　　　　　　　　　　　　　
増澤徹; 加藤裕介; 佐々木瑛祐; 小沼弘幸
第19回電磁力関連のダイナミクスシンポジウム, May 2007, 日本機械学会

ナノ振動負荷時の細胞周りの剪断応力解析　　　　　　　　　　　　　　　
橋本健児; 増澤徹; 木村孝之; 加藤綾子; 岸田晶夫; 木村剛
第46回日本生体医工学会大会, Apr. 2007, 日本生体医工学会

人工心臓ポンプ内の流れが磁気浮上インペラに及ぼす影響　　　　　　　　　　　　　　　
太田晶子; 増澤徹; 銭逸
第46回日本生体医工学会大会, Apr. 2007, 日本生体医工学会

複数低エネルギーの複合化による新しい生体接合技術の開発　　　　　　　　　　　　　　　
濱口崇志; 増澤徹; 加藤綾子; 尾関和秀; 木村孝之; 岸田晶夫; 木村剛; 樋上哲哉; 佐藤裕一郎; 山本芳郎
第46回日本生体医工学会大会, Apr. 2007, 日本生体医工学会

磁気浮上型人工心臓評価のための循環系シミュレータの開発　　　　　　　　　　　　　　　
黒須寛秋; 増澤徹; 石塚健太郎
人と福祉を支える技術フォーラム2007, 03 Mar. 2007, ライフサポート学会

磁気浮上血液ポンプの高機能化に関する研究　　　　　　　　　　　　　　　
佐々木瑛祐; 増澤徹; 加藤裕介
人と福祉を支える技術フォーラム2007, 03 Mar. 2007, ライフサポート学会

斜流ポンプ人工心臓のための小型磁気軸受の開発　　　　　　　　　　　　　　　
中山直久; 増澤徹; 鈴木健一; 加藤綾子
人と福祉を支える技術フォーラム2007, 03 Mar. 2007, ライフサポート学会

健康管理パーソナルロボットに関する基礎的研究　　　　　　　　　　　　　　　
石井博徳; 増澤徹; 加藤綾子
人と福祉を支える技術フォーラム2007, 03 Mar. 2007, ライフサポート学会

定常流ポンプ用磁気浮上技術　　　　　　　　　　　　　　　
増澤徹
日本定常流ポンプ研究会・第12回日本臨床補助人工心臓研究会, 31 Oct. 2006

定常流ポンプ用磁気浮上技術　　　　　　　　　　　　　　　
増澤徹
日本定常流ポンプ研究会・第12回日本臨床補助人工心臓研究会, Oct. 2006

中堅研究者からパイオニアへ：研究者として進化するには？　　　　　　　　　　　　　　　
増澤徹
第44回日本人工臓器学会大会, Oct. 2006, [Invited]

2次元的な磁束経路を形成するハイブリッド型磁気軸受の開発　　　　　　　　　　　　　　　
鈴木健一; 増澤徹
リニアドライブ研究会, Oct. 2006

重複バイアス磁束ハイブリッド型磁気軸受の開発　　　　　　　　　　　　　　　
小沼弘幸; 村上倫子; 柿原功一; 増澤徹
リニアドライブ研究会, Oct. 2006

バイアス磁束誘導型磁気軸受を用いた人工心臓の開発　　　　　　　　　　　　　　　
加藤裕介; 増澤徹
リニアドライブ研究会, Oct. 2006

磁気浮上型人工心臓のポンプ流量推定に関する研究　　　　　　　　　　　　　　　
石塚健太郎; 増澤徹
第44回日本人工臓器学会大会, Oct. 2006

人工心臓のためのバイアス磁石対向式ハイブリッド型磁気軸受の開発　　　　　　　　　　　　　　　
鈴木健一; 増澤徹
第44回日本人工臓器学会大会, Oct. 2006, [Invited]

人工心臓用磁気軸受の最適設計法の開発　　　　　　　　　　　　　　　
中山直久; 鈴木健一; 増澤徹
第44回日本人工臓器学会大会, Oct. 2006

バイアス磁束誘導型磁気軸受を応用した体外循環用血液ポンプの開発　　　　　　　　　　　　　　　
加藤裕介; 増澤徹
第44回日本人工臓器学会大会, Oct. 2006

振動エネルギー利用による生体接合技術の開発　　　　　　　　　　　　　　　
濵口崇志; 加藤綾子; 尾関和秀; 岸田晶夫; 木村剛; 樋上哲哉; 増澤徹
第44回日本人工臓器学会大会, Oct. 2006

人工心臓の血液接触面の表面粗さが溶血に及ぼす影響　　　　　　　　　　　　　　　
丸山修; 米谷幸治; 西田正浩; 山根隆志; 足立吉數; 大島郁也; 増澤徹
茨城講演会, 15 Sep. 2006

SPH法を用いた血流解析における赤血球モデルの改良　　　　　　　　　　　　　　　
中村信之; 田中伸厚; 増澤徹
茨城講演会, 15 Sep. 2006

バイアス磁束誘導型磁気浮上人工心臓の開発　　　　　　　　　　　　　　　
加藤裕介; 増澤徹
茨城講演会, 15 Sep. 2006

人工心臓用磁気軸受の最適設計　　　　　　　　　　　　　　　
中山直久; 増澤徹; 加藤綾子; 鈴木健一
茨城講演会, 15 Sep. 2006

人工心臓用バイパス磁石対向式ハイブリッド型磁気軸受　　　　　　　　　　　　　　　
鈴木健一; 増澤徹; 青砥良平
茨城講演会, 15 Sep. 2006

ナノ振動が細胞に与える影響　　　　　　　　　　　　　　　
橋本健児; 草間淳; 加藤綾子; 岸田晶夫; 木村剛; 木村孝之; 増澤徹
第4回生活支援工学系学会連合大会, Sep. 2006

機械的微小振動刺激の細胞分化に及ぼす影響に関する検討　　　　　　　　　　　　　　　
伊藤由樹子; 木村剛; 南広祐; 加藤綾子; 増澤徹; 岸田晶夫
第4回生活支援工学系学会連合大会, Sep. 2006

振動エネルギー利用による生体接合技術の開発　　　　　　　　　　　　　　　
濵口崇志; 加藤綾子; 岸田晶夫; 木村剛; 樋上哲哉; 増澤徹
第4回生活支援工学系学会連合大会, Sep. 2006

磁気浮上型人工心臓のポンプ流量推定に関する研究　　　　　　　　　　　　　　　
石塚健太郎; 増澤徹
第4回生活支援工学系学会連合大会, Sep. 2006

回転せん断負荷装置内の流れ解析　　　　　　　　　　　　　　　
西田正浩; 丸山修; 山根隆志; 増澤徹; 大島郁也
第4回生活支援工学系学会連合大会, Sep. 2006

せん断流れ場において表面粗さの大きさと面積が溶血に及ぼす影響　　　　　　　　　　　　　　　
丸山修; 沼田雄亮; 米谷幸治; 西田正浩; 山根隆志; 足立吉數; 大島郁也; 増澤徹
第4回生活支援工学系学会連合大会, Sep. 2006

人工心臓用小型ハイブリッド磁気軸受の開発　　　　　　　　　　　　　　　
増澤徹; 齋藤喬
第18回電磁力関連のダイナミクスシンポジウム, May 2006

磁気浮上型人工心臓の駆動状態推定方法の開発　　　　　　　　　　　　　　　
増澤徹
第45回日本生体医工学会大会, May 2006

ナノ振動と細胞機能制御　　　　　　　　　　　　　　　
増澤徹; 加藤綾子; 草間淳; 木村孝之; 岸田晶夫; 木村剛; 柴田隆行
第45回日本生体医工学会大会, May 2006

超音波メス制御による手術支援　　　　　　　　　　　　　　　
加藤綾子; 増澤徹; 樋上哲哉; 岸田晶夫; 佐藤裕一郎
第45回日本生体医工学会大会, May 2006

Characteritics of a Two-dimensional Integrated Magnetic Sensor for Position Sensing and Motor Control,　　　　　　　　　　　　　　　
T Kimura; K Takasaki; T Masuzawa
IEEJ Trans, Jan. 2006

磁気浮上型人工心臓のポンプ流量推定に関する研究　　　　　　　　　　　　　　　
石塚健太郎; 増澤徹
第44回日本人工臓器学会大会予稿集, Jan. 2006

Quick touch術式効果の工学的評価と超音波メス制御方式の検討　　　　　　　　　　　　　　　
能田高行; 増澤徹; 樋上哲哉; 岸田晶夫; 佐藤裕一郎
第３回生活支援工学系 学会連合大会講演予稿集, Dec. 2005

ナノ微小振動と細胞　　　　　　　　　　　　　　　
増澤徹; 草間淳; 木村孝之; 柴田隆行; 岸田晶夫; 木村剛
第３回生活支援工学系学会連合大会講演予稿集, Dec. 2005

SPH法による血流シミュレーションの赤血球モデルの比較　　　　　　　　　　　　　　　
早川裕次郎; 田中伸厚; 増澤徹
第３回生活支援工学系学会 連合大会講演予稿集, Dec. 2005

せん断流れ場において表面粗さが溶血に及ぼす影響　　　　　　　　　　　　　　　
丸山修; 西田正浩; 山根隆志; 大島郁也; 足立吉數; 増澤徹
第３回生活支援工学系学会連合大会講演予稿集, Dec. 2005

磁気浮上型人工心臓の技術課題　　　　　　　　　　　　　　　
増澤徹
日本定常流ポンプ研究会, 30 Nov. 2005

磁気浮上モーターの特性評価を目的とした二次元磁気センサの計測　　　　　　　　　　　　　　　
高崎慶吾; 木村孝之; 増澤徹
電気学会研究会資料, 17 Nov. 2005

細胞機能制御のためのMEMS細胞加振デバイスの開発　　　　　　　　　　　　　　　
吉田典央; 柴田隆行; 堀内宰; 増澤徹; 岸田晶夫
電気学会研究会資料, 17 Nov. 2005

人工心臓応用を目指した新しいハイブリッド型磁気軸受の開発　　　　　　　　　　　　　　　
齋藤喬; 中山直久; 増澤徹
電気学会研究会資料, Nov. 2005

人工心臓用磁気浮上モータの小型化と高効率化　　　　　　　　　　　　　　　
増澤徹; 加藤裕介
電気学会研究会資料, Nov. 2005

人工心臓に用いる磁性流体封入型動圧軸受に関する研究　　　　　　　　　　　　　　　
小林秀法; 増澤徹; 大島郁也
茨城講演会 講演論文集, 09 Sep. 2005

磁気浮上型小型ターボポンプの開発　　　　　　　　　　　　　　　
中山直久; 齋藤喬; 西田正浩; 山根隆志; 増澤徹
茨城講演会 講演論文集, 09 Sep. 2005

人工心臓用アキシャル型磁気浮上遠心ポンプの小型化　　　　　　　　　　　　　　　
加藤裕介; 増澤徹
茨城講演会 講演論文集, 09 Sep. 2005

Magnetically suspended pumps for artificial heart　　　　　　　　　　　　　　　
Toru Masuzawa
8th Japanese-Polish Seminar on New Engineering Methods Supporting Human Life, 55,, Sep. 2005

Magulev pump and zero power control　　　　　　　　　　　　　　　
ToruMasuzawa; Hiroyuki Onuma
13th Congress of the ISRBP, Sep. 2005

Hemolysis resulting from surface roughness under shear flow　　　　　　　　　　　　　　　
Osamu Maruyama; Masahiro Nishida; Takashi Yamane; Ikuya Oshima; Yoshikazu Adachi; Toru Masuzawa
13th Congress of the ISRBP, OS-2-3, 62, Sep. 2005

Accuracy enhancement of flow visualization analysis for hemocompatibility evaluation of rotary blood pumps　　　　　　　　　　　　　　　
M Nishida; T Yamane; H Kogure; T Chida; T Masuzawa
13th Congress of the ISRBP, PA-4,116, Sep. 2005

Magunetically suspended pumps for artificial heart　　　　　　　　　　　　　　　
Toru Masuzawa
第8回日本ポーランドセミナー, Sep. 2005

磁気浮上ポンプによるポンプ室内流体力の推定　　　　　　　　　　　　　　　
増澤徹
第３回生活支援工学系学会連合大会 講演予稿集, Aug. 2005

Cell function control by nano vibrations　　　　　　　　　　　　　　　
J Kusama; T Kimura; T Shibata; A Kishida; T
The First International Student Conference at Ibaraki University, 13 Jul. 2005

Development of a novel hybrid type magnetic bearing and application to micro centrifugal pumps for artificial hearts,　　　　　　　　　　　　　　　
Saito T; Nakayama N; Kakihara K; Okamoto T; Masuzawa T
The First International Student Conference at Ibaraki University, Jul. 2005

Development of two－Dimensional magnetic sensors for characterization of magnetic levitated motors　　　　　　　　　　　　　　　
K Takasaki; T Kimura; T Masuzawa
The First International Student Conference, Jul. 2005

人工心臓のための磁気浮上軸流ポンプの開発　　　　　　　　　　　　　　　
齋藤喬; 山根隆志; 西田正浩; 増澤徹
第43巻特別号 第44回日本生体医工学会大会プログラム・論文集, Apr. 2005

人工心臓のためのアキシャル型3軸制御磁気浮上モータの改良　　　　　　　　　　　　　　　
加藤裕介; 村上倫子; 小沼弘幸; 増澤徹
第44回日本生体医工学会大会プログラム・論文集, Apr. 2005

人工心臓用3軸制御型磁気浮上遠心ポンプの開発　　　　　　　　　　　　　　　
加藤裕介; 村上倫子; 小沼弘幸; 増澤徹
日本機械学会関東支部第11期総会 講演会講演論文集, Mar. 2005

磁気動圧浮上回転式ポンプ　　　　　　　　　　　　　　　
山根隆志; 西田正浩; 丸山修; 小西義昭; 山城直人; 増澤徹; 岡田養二
日本機械学会関東支部第11期総会講演会 講演論文集, Mar. 2005

人工心臓のための5軸制御型磁気浮上軸流ポンプの開発　　　　　　　　　　　　　　　
中山直久; 齊藤喬; 西田正浩; 山根隆志; 増澤徹
日本機械学会関東支部第11期 総会講演会講演論文集, Mar. 2005

径方向支持型磁気浮上遠心血液ポンプの開発現況　　　　　　　　　　　　　　　
小沼弘幸; 岡田養二; 築谷朋典; 巽英介; 妙中義之; 増澤徹
第33回人工心臓と補助循環懇話会 プログラム・抄録集, Jan. 2005

5軸制御型磁気浮上軸流ポンプの開発　　　　　　　　　　　　　　　
齊藤喬; 山根隆志; 西田正浩; 増澤徹
第33回人工心臓と補助循環懇話会プログラム・抄録集, Jan. 2005

ナノバイブレーションによる細胞機能制御　　　　　　　　　　　　　　　
草間淳; 石丸正臣; 木村孝之; 柴田隆行; 岸田晶夫; 増澤徹
第33回人工心臓と補助循環懇話会プログラム・抄録集, Jan. 2005

アキシャル型磁気浮上モータを用いた人工心臓用遠心ポンプの開発　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹; 加藤勇
日本機械学会論文集, Jan. 2005

人工心臓用ラジアル型磁気浮上遠心ポンプの最適化　　　　　　　　　　　　　　　
小沼弘幸; 岡田養二; 増澤徹
第17回バイオエンジニアリング講演会講演論文集, Jan. 2005

血流のミクロ・シミュレーション　　　　　　　　　　　　　　　
高野龍雄; 田中伸厚; 増澤徹
日本機械学会論文集, Nov. 2004

医療機器の今後10年間の展望、人工臓器－人工心臓を中心に－、　　　　　　　　　　　　　　　
増澤徹
医科器械学 創立80周年記念誌, Jun. 2004

Feed Forward医療の提唱－新しいエムイ－技術創出－　　　　　　　　　　　　　　　
増澤徹
生体医工学 第42巻特別号 第43回日本エム・イー学会大会プログラム・論文集, May 2004

径方向支持型磁気浮上モータを用いた完全磁気浮上遠心血液ポンプの改良、　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹; 岡田養二; 築谷朋典; 妙中義之
生体医工学 第42巻特別号第43回日本エム・イー学会大会プログラム・論文集, May 2004

アキシャル型3軸制御磁気浮上遠心血液ポンプの開発　　　　　　　　　　　　　　　
村上倫子; 増澤徹; 小沼弘幸
生体医工学第42巻特別号 第43回日本エム・イー学会大会プログラム・論文集, May 2004

インピーダンスを利用した穿刺深さ計測法の開発、　　　　　　　　　　　　　　　
増澤徹; 小林誉之; 孫彦斌; 柴田隆行; 岸田晶夫
生体医工学第42巻特別号 第43回日本エム・イー学会大会プログラム・論文集, May 2004

ナノバイブレーションによる細胞機能制御システムの開発　　　　　　　　　　　　　　　
石丸正臣; 増澤徹; 草間淳; 柴田隆行; 岸田晶夫; 木村剛; 宮崎幸造
ナノバイブレーションによる細胞機能制御システムの開発、, May 2004

実用化にむけた磁気浮上型人工心臓の開発　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹; 大島郁也; 近藤良; 岡田養二
第2回SVBL成果報告会, Mar. 2004

磁気浮上型人工心臓　　　　　　　　　　　　　　　
増澤徹
電気学会技術報告第958号, Mar. 2004

軸流ポンプ用小型磁気浮上システムの開発　　　　　　　　　　　　　　　
齋藤喬; 小沼弘幸; 岡田養二; 増澤徹
SVBL第2回成果報告会, 28 Feb. 2004

生体組織の粘弾性評価に関する研究‐幼児と成人の筋肉の粘弾性評価-　　　　　　　　　　　　　　　
中村太一; 小川真由美; 増澤徹
人と福祉を支える技術フォーラム, Feb. 2004

アキシャル型磁気浮上人工心臓の高機能化に関する研究　　　　　　　　　　　　　　　
大沢卓也; 村上倫子; 小沼弘幸; 増澤徹
人と福祉を支える技術フォーラム, Feb. 2004

ラジアル型磁気浮上人工心臓の改良に関する研究　　　　　　　　　　　　　　　
野津英孝; 小沼弘幸; 増澤徹; 岡田養二; 築谷朋典; 妙中義之
人と福祉を支える技術フォーラム, Feb. 2004

ナノバイブレーションによる細胞機能制御システムの開発　　　　　　　　　　　　　　　
草間淳; 石丸正臣; 増澤徹; 木村孝之; 岸田晶夫; 木村剛; 宮崎幸造
人と福祉を支える技術フォーラム, Feb. 2004

アキシャル型磁気浮上モータを用いた人工心臓の開発　　　　　　　　　　　　　　　
小沼弘幸; 増澤徹
第16回バイオエンジニアリング講演会講演論文集, Jan. 2004, [Invited]

次世代型磁気浮上定常流ポンプの開発現況　　　　　　　　　　　　　　　
増澤徹; 岡田養二
第10回日本定上流ポンプ研究会, Oct. 2003

アキシャル方向支持型磁気浮上モータを使用した遠心血液ポンプの開発　　　　　　　　　　　　　　　
小沼弘幸; 加藤勇; 増澤徹
第41回日本人工臓器学会大会予稿集, Oct. 2003