Patent ID: 6638011
Filing Date: 2003-10-28
Classification: A61M,F01D,F04D,F16C,Y10S

Abstract:
A rotary blood pump for use in a heart assist device, said pump having an impeller suspended in use within a pump housing exclusively by hydrodynamic thrust forces generated by relative movement of said impeller with respect to and within said pump housing; and wherein at least one of said impeller or said housing includes at least a first deformed surface lying on at least part of a first face which, in use, moves relative to respective facing surfaces on the other of said impeller or said housing thereby to form a relatively moving surface pair which generates relative hydrodynamic thrust between said impeller and said housing which includes everywhere a localized thrust component substantially and everywhere normal to the plane of said first deformed surface and wherein said impeller includes blades which are tapered or non-planar, so that a thrust is created between the edges and the pump housing during relative movement there between and wherein said edges of said blades are shaped such that the gap at the leading edge of the blade is greater than at the trailing edge and thus the fluid which is drawn through the gap experiences a wedge shaped restriction which generates a thrust.