Basic Research on Seal-less Centrifugal Blood Pump

点击翻译按钮获取中文摘要

We aim at improving the performance of seal-less centrifugal blood pumps (nutation on type and magnetic suspension type) as an artificial heart of next generation.I.Nutation Type : We replaced the nutating impeller by an undulating circular disc of double action in order to obtain the higher pressure at the lower rotational speed. The pump performance proved to be improved by narrowing the clearance between the edge of disc and the casing, and also by widening the inlet port of diaphragm side.II.Magnetic suspension Type : (1) Animal experiments verified that the present pump has endurance of more than one year. (2) Without flow meter and pressure transducers, the flow rate and pressure difference can be estimated from the measured motor current and the motor speed. (3) The stability of rotational impeller magnetically suspended was measured by Laser position sensers. This show that the radially straight vane is most stable. (4) By viewing from the same rotational coordinate as rotating impeller, the flow patterns in various kinds of impellers were revealed.III.Computational Flow Analysis : (1) Distribution of turbulent shear stress in the orifice were computed using the low Reynolds number turbulent model and then the threshold of shear stress for hemolysis were determined. (2) Flows around a nutating circular cylinder were analyzed by the discrete vortex method with diffusion velocit.