DEVELOPMENT OF PUSHER-PLATE TYPE TAH SYSTEM - EVALUATION OF ITS DRIVING-CONTROLLABILITY.

With the aim of developing a completely implantable total artificial heart system, pusher-plate (PP) type TAH and versatile control-drive systems were developed. The PP pumps incorporate Hall effect sensors to provide PP movement continuously, this signal then is used to compute beat-to-beat pump output as well as to control PP movement precisely. Each pump can be operated at a fixed pulse rate (FR), variable pulse rate (VR) or in synchrony with the ECG P-wave. In the VR mode, pump stroke volume is regulated at a preset level utilizing a Hall effect signal, while the pump rate is allowed to vary depending on the preload and afterload. Both in-vitro and in-vivo studies demonstrated satisfactory performances of both pump and drive systems in controlling the hemodynamics. Also Hall sensor derived pump output values agreed well with the volumetric measurement (r equals 0. 996).