Development and Evaluation of a Seamless Left Heart Assist Blood Pump

摘要

A valved blood pump made from a single continuous elastomer (Avocothane 51 or Avcomat 610) has been developed. The pump weighs 65 g, has a 110 cc stroke volume, and 69% volumetric efficiency. It is fabricated with no steps or seams anywhere between the apical inflow and aortic outflow. The pump incorporates sinus-contoured tri-leaflet valves integral to the inflow and outflow conduits (18.5 mm dia, 14 mm Hg pressure gradient at 30 L/min). In vitro a flow of 10 L/min with 75% pump efficiency at 90 BPM has been achieved. In vivo experiments, in calves have demonstrated its effectiveness for circulatory support of the left ventricle during continuous assist for up to 45 days, (elective termination of health animal) without anticoagulant or antiplatelet therapies. These experiments have confirmed the importance of surface smoothness and high shear rates in minimizing thrombosis. The valves have functioned in vivo for up to 11 months. In vitro the pump has been fatigued in real time to 30.5 million cycles, and valves to 54 million cycles. (Ninety-seven million cycles at accelerated rates).