DEVELOPMENT OF A TOTALL IMPLANTABLE, MOTOR DRIVEN ARTIFICIAL HEART SYSTEM

开发完全植入式电机驱动人工心脏系统

• 批准号: 10044232
• 负责人: TAKATANI Setsuo
• 金额: $ 2.82万
• 依托单位: TOKYO MEDICAL AND DENTAL UNIVERSITY (1999-2001)Yamagata University (1998)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10044232/
• 关键词: Electromechanical TAH; Electromechanical VAD; Heart Transplantation; Continuous Flow Pumps; Centrifugal Blood Pump; Biocompatibility; Durability; Compliance Chamber; 全置換型人工心臓; 補助人工心臓; Ti-6Al-7Nbチタン合金; ポリウレタン3尖弁; 流れの可視化; 拍動流補助人工心臓; 連続流補助人工心臓

In this project, in collaboration with Prof. H Reul's group of Helmholtz Institute of Biomedical Engineering, TechnicalUniversity Aachen, Aachen, Germany, the main objective was to develop a totally implantable, ultracompact electromechanical total artificial heart (TAH) and ventricular assist device (VAD). Both TAH and VAD Systems are based on transmitting the electrical energy through skin using a transcutaneous energy transmission (TET) system to power the implanted blood pump. The implanted components include thes pumping unit, compliance chamber, internal battery, and the controller. The TAH pumping unit is an one-piece design sandwiching an electromechanical actuator between the left and right pumps. The VAD was made using the same actuator as TAH's and covering the right side of the TAH with a backplate. The diameter and thickness of the TAH are 90mm and 70mm, respectively, and its volume is 400cc with the weight being 450g. Those of the VAD are 90mm and 56mm, respectively, yiel … More ding the volume of 275cc and weight of 460g. Although downsized, the maximum floy of 8L/min was obtained at the pumping rate of 160BPM. The power required for TAH ranged from 10 to 15 watts, while that of VAD from 5 to 8 watts. The maximum electrical to hydraulic efficiency of the TAH was 13.5% and that for VAD was 23%.As a volume compensator, 55cc air-filled chamber was designed for TAH, while for VAD 75cc chamber. The flexing membrane was made of polyurethane with its thickness being around 0.2mm. The secondary rechargeable batteries such as NiMH and Li-ion were tested for their performance with the TAH and VAD. With the terminal voltage of 16V, both batteries were able to power the artificial heart for over a duration of 2 hours.In vivo studies with VAD and TAH have just started to evaluate their durability and biocompatibility. When long term durability and biocompatibility were demonstrated, we will move into clinical trials.In addition to pulsatile systems, we also started to design and evaluate the centrifugal blood pump. The centrifugal blood pump is a tri-pod mechanism supporting the impeller. The basic performance in terms of head pressure-flow was obtained. The results indicated that the prototype pump meet the requirements as the left ventricular assist device. However, because of high friction wear at the tri-pod and polyethylene groove interface, we changed the pump design to a single pivot bearing mechanism. With improvement in impeller stability, this pump may meet requirements for clinical ventricular assist device. Further study will follow in future.As a monitoring system of the artificial heart implanted patient, an optical reflectance sensor to measure blood hemoglobin level and oxygen saturation was developed. Its accuracy in terms of hemoglobin level and oxygen saturation was evaluated using bovine blood. The results indicated feasibility of the sensor for continuous patient monitoring, provided its long term performance has been proven in animals.Through collaboration with Helmohotz Institute, we were fortunate to exchange not only the staff members, but also students. We received three master's students who worked on the optical sensor project. One of our students spent six months in Aachen learning computation fluid dynamic approach to analyze blood flow pattern inside the continuous flow devices. Also, we organized two Japan-Germany artificial heart symposiums, one in 1998 and the other in 2000. Through these exchange programs, we were fortunate to learn valuable information to help better design and analyze blood pump data. I think exchange program provided valuable experience to the students as well as staff members. Less

在这个项目中，与德国亚琛理工大学Helmholtz生物医学工程研究所H Reul教授的团队合作，主要目标是开发一种完全可植入的、超致密的机电全人工心脏(TAH)和心脏辅助装置(VAD)。TAH和VAD系统都是基于通过皮肤传输电能，使用经皮能量传输(TET)系统为植入的血泵提供动力。植入的部件包括抽油机、顺应室、内部电池和控制器。TAH抽油机是一种一体式设计，在左泵和右泵之间夹有一个机电执行器。VAD使用与TAH相同的致动器，并用背板覆盖TAH的右侧。TAH的直径为90 mm，厚度为70 mm，体积为400cc，重量为450g。VAD分别为90 mm和56 mm，Year…体积为275毫升，重量为460克。当泵速为160次/分时，浮选效果最好，达到8L/min。TAH所需的功率为10至15瓦，而VAD所需的功率为5至8瓦。TAH的最大电液效率为13.5%，VAD的最大电液效率为23%。作为体积补偿器，TAH设计了55cc的充气室，而VAD设计了75cc的充气室。挠性膜由厚度为0.2 mm左右的聚亚安酯制成。用TAH和VAD对镍氢和锂离子二次充电电池的性能进行了测试。在终端电压为16V的情况下，两种电池都能够为人造心脏提供超过2小时的电力。VAD和TAH的体内研究刚刚开始评估它们的耐用性和生物兼容性。当长期耐用性和生物相容性被证明后，我们将进入临床试验。除了脉动系统，我们还开始设计和评估离心式血泵。离心式血泵是支撑叶轮的三脚架机构。得到了压头压力-流量关系的基本性能。结果表明，样机泵满足作为左心辅助装置的要求。然而，由于三柱体和聚乙烯沟槽界面的高摩擦磨损，我们将泵的设计改为单枢轴轴承机构。随着叶轮稳定性的提高，该泵可满足临床脑室辅助装置的要求。作为人工心脏植入患者的监测系统，研制了一种用于测量血液中血红蛋白水平和血氧饱和度的光学反射式传感器。它在血红蛋白水平和血氧饱和度方面的准确性是用牛血来评估的。结果表明，该传感器用于连续患者监测是可行的，只要它的长期性能已经在动物身上得到证实。通过与赫尔莫霍兹研究所的合作，我们幸运地不仅交流了工作人员，也交流了学生。我们接待了三名从事光学传感器项目的硕士研究生。我们的一名学生在亚琛花了六个月的时间学习计算流体动力学方法来分析连续流动设备内的血液流动模式。此外，我们还组织了两次日本-德国人工心脏研讨会，一次是在1998年，另一次是在2000年。通过这些交流项目，我们有幸获得了有价值的信息，以帮助更好地设计和分析血泵数据。我认为交流项目为学生和工作人员提供了宝贵的经验。较少

项目成果

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海和,高谷他: "磁気浮上型遠心ポンプ内における光学的手法による血液のヘマトクリット測定" 人工臓器. 28巻1号. 173-177 (1999)

Kaiwa, Takatani 等人：“在磁悬浮离心泵中使用光学方法测量血液血细胞比容”，Artificial Organs，第 28 卷，第 1. 173-177 期（1999 年）。

Takatani S, Nakamura M, Ohuchi K, Nogawa M, Sakamoto T: "Ultracompact, Completely Implantable Electro-mechanical permanent TAH"Journal of Congestive Heart Failure and Circulatory Support. 1(4). 161-166 (2001)

Takatani S、Nakamura M、Ohuchi K、Nokawa M、Sakamoto T：“超紧凑、完全植入式机电永久 TAH”充血性心力衰竭和循环支持杂志。

Kaiwa T,Takatani S et al: "Measurement of blood hematocrit inside the magnetically suspended centrifugal pump using an optical technique" Artificial Organs. (in press). (1999)

Kaiwa T、Takatani S 等人：“使用光学技术测量磁悬浮离心泵内的血细胞比容”人工器官。

Yuhki A,Nogawa M,Takatani S: "Development of a compact, seal-less, tripod supported, magnetically driven centrifugal blood pump"Artificial Organs. 24(6). 501-505 (2000)

Yuhki A、Nokawa M、Takatani S：“开发紧凑型、无密封、三脚架支撑、磁驱动离心血泵”人工器官。