[Design and preliminary experiment of an intelligentized physiologic pulsatile flow cardiac support system]

A patent cardiac support system which is used as a bridge treatment for acute myocardial infarction has been designed and tested in vitro and in two dogs in vivo. This is an easy-to-use intelligentized pulsatile flow cardiopulmonary bypass device to replace the function of heart. The device consists of two identical pumps and perfusion chambers, a sensing and control system, a gas exchanger between the vein and pump, two one way valves between pump and veins or arteries. Arterial pressure and EKG feedback mechanisms are used for maintaining blood pressure and coordinating the pumping activity with heart contraction. A prototype of the device was built to perform hydraulic in vitro tests with aims of verifying the new device's pumping behavior. Functional evaluation of the device was carried out by using it in a model circuit made with standard CPB components plus a mock hydraulic pipeline. This system demonstrated easy manipulation, good controllability, and provided a 65+/-2ml x beat(-1) flow volume. There was a linear correlation between peak pressure value and pulsatile frequency. In the two in vivo experiments, the primary objective was to determine whether the device could work well in dog, whether physiologic pulsatility could be achieved and whether the blood supply to heart should be sufficient during asystole status by drugs. The results suggest that all the goals have been achieved.