US Patent 8002518 Rotary pump with hydrodynamically suspended impeller

A pump assembly adapted for continuous flow pumping of blood. In a particular form the pump is a centrifugal pump wherein the impeller is entirely sealed within the pump housing and is hydrodynamically suspended therein as the impeller rotates within the fluid urged by electromagnetic means external to the pump cavity. Hydrodynamic suspension is assisted by the impeller having deformities therein such as blades with surfaces tapered from the leading edges to the trailing edges of bottom and top edges thereof.