Abstract
Totally implantable, compact, high performance, electro-mechanical pulsatile ventricular assist device (VAD) has been developed. The diameter and thickness of the pump are 90 and 56mm, and volume and weight are 275cc and 450g; this compact size enables an easy application to 50-60Kg patients. The energy converter consists of a DC brush-less motor and a planetary roller screw. The blood pump is pusher-plate type with the stroke volume being 55.8cc. The pump housing is made of titanium alloy (Ti-6Al-7Nb) and flexing blood contacting diaphragm is made of Bio-Span polyurethane. A micro-processor is used to control the pump based on the motor rotor commutation signals and pusher-plate position signal. In vitro evaluation revealed that the pump can deliver about 4-5L/min flow against 100mmHg afterload with 10mmHg preload require 5-6watts power. It can provide the max. flow of 8.lL/min and the max. electrical to hydraulic efficiency is about 24%. This VAD is ready for long term endurance test as well as systematic chronic animal study to evaluate its anti-thrombogenic as well as system performance, prior to clinical use.
