Lioi A P, Orth J L, Crump K R, Diffee G, Dew P A, Nielsen S D, Olsen D B
Institute for Biomedical Engineering, University of Utah, Salt Lake City.
Artif Organs. 1988 Apr;12(2):152-62. doi: 10.1111/j.1525-1594.1988.tb02748.x.
The in vitro development of automatic control of the actively filled, alternately pumped, volumetrically coupled, electrohydraulic total artificial heart was the goal of this investigation. Control features under study were (a) cardiac output (CO) response to preload; (b) CO relationship to mean aortic pressure (AoP); and (c) control of balanced ventricular outputs. A modified pulmonic valve to increase backflow was used as a balancing mechanism. Hydraulic fluid pressure transducers monitored diastolic pressures, and microprocessor control of motor speed maintained in a mild suction to yield filling rate dependent on atrial pressure. Results indicated a rise in CO from 5 to 9 L/min, with a change in mean right atrial pressure (RAP) from 0 to 7 mm Hg. No significant difference in CO was found as AoP was varied from 80 to 120 mm Hg with a maximum variation of +/- 0.5 L/min on CO and +/- 1 mm Hg on RAP. Balance was maintained for bronchial flows up to 50% with mean left atrial pressure never exceeding 15 mm Hg. An alternately pumped electrohydraulic heart was automatically controlled to respond sensitively to preload changes. Afterload changes did not alter the CO response curve. Automatically controlled, balanced ventricular outputs were maintained.
本研究的目标是对主动充盈、交替泵送、容积耦合的电动液压全人工心脏进行体外自动控制开发。所研究的控制特性包括：(a) 心输出量（CO）对前负荷的反应；(b) CO与平均主动脉压（AoP）的关系；以及(c) 平衡心室输出量的控制。使用改良的肺动脉瓣增加反流作为平衡机制。液压流体压力传感器监测舒张压，微处理器控制电机速度以保持轻微吸力，从而产生取决于心房压力的充盈率。结果显示CO从5升/分钟升至9升/分钟，平均右心房压力（RAP）从0毫米汞柱变为7毫米汞柱。当AoP在80至120毫米汞柱之间变化时，CO无显著差异，CO的最大变化为±0.5升/分钟，RAP的最大变化为±1毫米汞柱。当支气管血流量高达50%时保持平衡，平均左心房压力从未超过15毫米汞柱。交替泵送的电动液压心脏被自动控制以对前负荷变化做出敏感反应。后负荷变化未改变CO反应曲线。维持了自动控制的、平衡的心室输出量。
