Patent ID: 8668473

Claim:
An axial flow blood pump comprising: an impeller rotatable on a rotation axis within a cylindrical lumen, the impeller having a radially projection-free cylindrical circumference with a blood upstream and a blood downstream end and a plurality of spaced apart grooves each extending substantially axially along said cylindrical circumference from a blood entrance opening to a blood exit opening, each groove being defined by adjacent sidewalls as boundaries for peripheral surface areas of the impeller between said grooves, the width of each groove at circumferential axial positions on the impeller being substantially smaller than the width of adjacent peripheral surfaces areas at such positions, said sidewalls of each groove converging to establish a relatively narrowing portion thereof not parallel to said rotation axis between said blood entrance and blood exit openings, said sidewalls thereafter diverging to establish a widening axially oriented portion terminating at said blood exit opening; said peripheral surface areas being magnetically coupled with proximal magnetic stator elements and defining hydrodynamic thrust bearing surfaces to enable said impeller to rotate freely within the blood contained in said lumen.