抄録
Well controlled man-machine interaction is one of the most mandatory factors in circulatory assist. We designed a long-term extracorporeal circulation system possessing a servomatic flow controlling mechanism with closed circuit.
The bypass circuit is illustrated in Fig. 1. Venous blood is allowed to drain by gravity flow into a reservoir bag with a capacity of 1000ml or 600ml (Fig. 2). Blood is drawn from the reservoir to the roller pump and then pumped through the membrane, through the heat exchanger, to the arterial cannula.
The mechanism of the servomatic regulation of the pump flow is shown in Fig. 5. The system is designed to determine the pump flow to the appointed speed, in accordance with the change in the blood level of the reservoir which is detected by four sensors (Efector; ifm-Japan Co., Ltd.).
Dog experiments have shown us that this system is quite safe, easy to operate and has a very desirable regulating effects from the viewpoint of stabilizing the preload of the natural heart.
