Massiello A, Kiraly R, Butler K, Himley S, Chen J F, McCarthy P M
Department of Biomedical Engineering, Cleveland Clinic Foundation, Ohio.
J Thorac Cardiovasc Surg. 1994 Sep;108(3):412-9.
We describe the design and in vitro testing of the Cleveland Clinic-Nimbus electrohydraulic permanent total artificial heart as it nears completion of development. The total artificial heart uses an electric motor and hydraulic actuator to drive two diaphragm-type blood pumps. The interventricular space contains the pump control electronics and is vented to an air-filled compliance chamber. Pericardial tissue valves and biolized blood-contacting surfaces potentially eliminate the need for anticoagulation. In vitro studies on a mock circulatory circuit demonstrated preload-sensitive control of pump output over the operating range of the blood pump: 70 to 160 beats/min and 5 to 9.6 L/min at right and left atrial pressures of 1.0 to 7.0 mm Hg and 5.0 to 12.0 mm Hg, respectively. The pump output was found to be insensitive to afterload over a range of 15 to 40 mm Hg mean pulmonary artery pressure and 60 to 130 mm Hg mean systemic pressure. The left master alternate control mode balanced the ventricular outputs during simulated bronchial artery shunting of up to 20% of cardiac output. A 10% to 15% right-pump, stroke-volume limiter balanced ventricular outputs during maximum output of 9.6 L/min. In response to a sustained increase in systemic venous return, the pump increased output by 2 L/min (29%) in 35 seconds. Thus the Cleveland Clinic-Nimbus total artificial heart meets the National Heart, Lung, and Blood Institute hemodynamic performance goals for devices being developed for permanent heart replacement. The biolized blood-contacting surfaces should decrease the risk of thromboembolism associated with circulatory assist devices.
我们描述了克利夫兰诊所 - 宁布斯电动液压永久性全人工心脏在接近研发完成时的设计及体外测试情况。该全人工心脏使用电动马达和液压致动器来驱动两个隔膜式血泵。心室空间包含泵控制电子设备，并通向一个充满空气的顺应腔。心包组织瓣膜和生物化的血液接触表面可能无需进行抗凝。在模拟循环回路中的体外研究表明，在血泵的工作范围内，泵输出对前负荷敏感：右心房压力为1.0至7.0毫米汞柱、左心房压力为5.0至12.0毫米汞柱时，心率为70至160次/分钟，流量为5至9.6升/分钟。发现在平均肺动脉压为15至40毫米汞柱和平均体循环压力为60至130毫米汞柱的范围内，泵输出对后负荷不敏感。在模拟支气管动脉分流高达心输出量的20%时，左主交替控制模式平衡了心室输出。一个10%至15%的右泵冲程容积限制器在最大输出为9.6升/分钟时平衡了心室输出。响应全身静脉回流的持续增加，泵在35秒内将输出增加了2升/分钟（29%）。因此，克利夫兰诊所 - 宁布斯全人工心脏达到了美国国立心肺血液研究所为正在研发的用于永久性心脏置换的设备设定的血流动力学性能目标。生物化的血液接触表面应降低与循环辅助设备相关的血栓栓塞风险。
