DEVELOPMENT OF COMPUTER CONTROLLED CARDIO-PULMONARY BYPASS SYSTEM

本文介绍了一种用于体外循环（CPB）的脉动式滚压泵及其流量自动控制系统。脉动泵采用了新设计的泵头，减小了流量和压力波形的相对波动。滚子和壳体之间的间隙变化，使得泵管的体积与转子旋转的角度成正比。离体实验表明，相对波动率为常规辊式卸料的30%~ 85%。在临床应用中，该泵产生了令人满意的脉动压力波形。通过200例临床病例对该泵的可靠性进行了探讨。微计算机完全控制整个CPB过程中的血流和压力。流量控制器采用采样周期为1秒的数字PI（比例积分）控制算法。20只狗的实验结果表明，该控制系统能较好地维持输液和回输流量。

A pulsatile roller pump and an automatic flow control system for cardio-pulmonary bypass (CPB) have been developed. The pulsatile pump has a newly designed head casing to reduce relative fluctuation of flow and pressure waveform. The clearance between rollers and the casing varies such that the volume of pumping tube is directly proportional to the angle of rotor rotation. In vitro experiments shows that the relative fluctuation ratio is ranging from 30 to 85 % of conventional roller dump. In clinical cases, the pump produced pulsatile pressure waveform satisfactory. The reliability of the pump was probed by 200 clinical cases.The automatic control system consists of pumps and 16 bit micro-computer. The micro-computer completely controls blood flow and pressure throughout CPB. the digital PI (Proportional-Integral) control algorithm with a sampling period of 1 second, is used for flow controller. The results of 20 dog experiments indicate that this control system maintains infusion and withdrawal flow satisfactory.