Logic controlled blood pump - has cannula with liq. detector and pressure monitor operating pump within safe limits

摘要

A blood pump for use during heart operations has a cannula (1) through which the blood passes, connected by a line (2) to a peristaltic pump (3) connected to a reservoir vessel (4) with a return line (5). The cannula contains two electrodes (6, 7) acting as liquid detectors and connected to a control unit which can start and stop the pump. A branch line (15) connected to the control unit is also connected by a by-pass link (13) with a control orifice (14) to the return line (5). The branch line is connected to a pressure indicator (16) which may control a photo-electric system with photo transistors connected to a logic circuit so that the pump is also controlled between pressure limits.