Abstract
We have been developing a nutating centrifugal pump as pulsatile and non-pulsatile blood pimp. This pump, so called Tea-Spoon type pump (TS-pump), is about 40% in efficiency. l'e aim at improving its pump efficiency. Model test of 2-dimensional TS-pump showed that a narrow clearance bctwcei, impeller and casing increases efficiency. Pressure profile along the inside wall of annular impeller passage was measured in 3-dimensional prototype TS-pump. Maximum shear stress and velocity profile in the c.learance was estimated by a simplified fubrication theory from the observed pressure distribution along the clearance. This proved that the more narrow clearance else reduces the more shear stress relevant to hemolysis. We undertake testing newly-developed TS-pumps which have narrow clearance, smaller impeller and improved profile of casing.
