A computerized control system for assisted circulation

利用微机开发了辅助循环控制系统。该控制系统由一个微型计算机、一个离心泵、一个静脉管闭塞器和一个储液器的液位传感器组成，在辅助循环过程中调节动脉输注和静脉回撤流量。计算机监测中心静脉压、左心房压、主动脉压、血容量，并以1秒的控制间隔控制泵的转速和封堵器的开度。计算机将输液流速保持在预定范围内，并将左心房压力调节到一个设定值，以维持主动脉压力。我们设计了一种在线筛选算法，以防止压力测量中的伪影改变流量。对2例心内直视术后低输出综合征患者应用计算机化控制器，连续4天调节血流速率和左心房压。

A control system for assisted circulation was developed utilizing a microcomputer. The control system, consisting of a microcomputer, a centrifugal pump, a venous tube occluder, and a level sensor for a reservoir, regulates both arterial infusion and venous withdrawal flow throughout assisted circulation. The computer monitors central venous pressure, left atrium pressure, aortic pressure, and the amount of blood in the reservoir and controls the rotational speed of the pump and the degree of opening of the tube occluder with a control interval of one second. The computer keeps the infusion flow rate within a predetermined range and regulates left atrium pressure to a set point in order to maintain aortic pressure. We designed an online screening algorithm to prevent artifacts on pressure measurements from changing the flow rates. The computerized controller was applied on two patients with low output syndrome after the open-heart surgery and regulated the flow rate and left atrium pressure for four days.