Clarification of the pathophysiological mechanism associated with a total artificial heart (TAH) and establishment of optimum control method of TAH

本研究的目的是阐明人工心脏体外循环过程中出现的贫血、中心静脉压升高、甲状腺激素降低等病理生理问题的发生机制，建立人工心脏体外循环的最佳控制方法。在这4年中取得了以下成果：1.为了提高血泵的抗凝血性能，研制了一种新型的聚合物膜阀--水母阀。通过该瓣膜的使用，大大提高了血泵的抗凝血性，消除了许多病理生理问题，为阐明病理生理问题的机制提供了线索。该阀门在国际上引起了重视，并与美国和欧洲的许多实验室开始了合作研究。我们发现，当我们切断升主动脉以连接左侧流出管时，山羊发生了强烈的神经反射，这是在我们将导管连接到Des…时从未经历过的更多的卷曲的主动脉。在肾功能方面，我们发现TAH植入后肾血浆流量、肾血流量和肾小球滤过率均显著降低，其原因可能与中心静脉压升高有关。为探讨中心静脉压(CVP)升高的原因，观察TAH对心钠素(ANP)动态变化的影响。我们发现，虽然心钠素的分泌不受TAH泵的影响，但随着CVP的增加，心钠素的分泌并没有增加，而且心钠素对肾脏的利钠作用受到了强烈的抑制。塔赫山羊。在人工心脏的控制方面，采用全右心搭桥和人工心脏上下半身分离循环的方法，阐明了循环系统和自然心脏的控制机制。利用这些实验结果，提出了一种新的自动控制方法，即根据总外周电阻的变化来控制TAH的输出。该方法能使TAH动物保持良好的运动状态，使中心静脉压保持在正常范围。较少

The objectives of this study are to clarify the mechanism of pathophysiological problems such as anemia, CVP elevation, low thyroid hormone, etc., generated during the total artificial heart pumping, and to establish an optimum control method of total artificial heart. The following results has been obtained in these 4 years.1. To improve the antithrombogenicity of the blood pump, a new polymer membrane valve, jellyfish valve, was developed. By using this valve the antithrombogenicity of the blood pump was improved greatly and many pathophysiological problems were disappeared, which would give us a hint to clarify the mechanism of pathophysiological problems. The valve was attracted attention internationally, and the cooperative research has begun with many laboratories in USA and Europe.2. We found that a strong nervous reflex occured in the goat when we cutoff an ascending aorta to connect a left outflow cannula, which had never been experienced when we connected the cannula to a des … More cending aorta.3. Concerning the renal functions, we found that renal plasma flow, renal blood flow, and glomerular filtration rate showed significantly decreases after TAH implantation and that the cause of these phenomena would be due to a CVP elevation.4. To seek the cause of CVP elevation, the influence of TAH on the dynamics of atrial natriuretic peptide (ANP) was studied. We found that although the secretion of ANP was not changed by TAH pumping, it did not increase when CVP increased, and that the natriuretic effect of ANP on the kidney was strongly suppressed in. TAH goats.5. As for the control of artificial heart, total right heart bypass and separate circulation between upper and lower half body with an artificial heart were carried out to clarify the control mechanism of the circulatory system and natural heart. Utilizing the results obtained from these experiments, a new automatic control method in which the output of TAH was controlled with the changes in total peripheral resistance. This method could keep a TAH animal in a good condition including exercise state and keep CVP in normal range. Less