Abstract
An automatic flow control system for cardio-pulmonary bypass (CPB) has been developed. The system consists of three micro-computers, one is used for pulsatile infusion pump, another for operational console, and the other for pressure and flow control. The micro-computer completely controls blood flow and pressure throughout CPB. At the beginning of CPB, the system starts with 26ml/kg/min of infusion flow and increases to 80ml/kg/min automatically and controls venous withdrawal flow to minimize the error between central venous pressure (CVP) and CVP preset point. Modified PI (Proportional-Integral) control algorithm with a sampling period of 3 seconds, is used for CVP controller. The results on 16 dog experiments indicate, more than 96% of total CPB period, this control system maintains CVP within ±1mmHg error of CVP preset point.
