Patent ID: 7229258

Claim:
A blood pump, comprising: a stator having a cavity extending therethrough; an impeller, rotatably disposed and magnetically suspended within the cavity of the stator, the impeller defining an axis of rotation, and the stator and impeller defining a fluid passage therebetween; a plurality of magnetic bearings, including passive permanent magnet and active electromagnetic bearings, suspending the impeller within the cavity of the stator, and having impeller magnets on the impeller and stator magnets or coils/poles on the stator; a motor including impeller magnets on the impeller and coils/poles associated with the stator; a single, annular blood flow path extending axially through the cavity between a cylindrical wall of the cavity of the stator and the impeller at least around blades of the impeller, with the cylindrical wall of the cavity of the stator forming a continuous outer cylindrical surface of the annular blood flow path having a circular cross section, the continuous outer cylindrical surface reducing boundary layer separation, recirculation, stagnation and wake in blood flowing through the annular blood flow path; and an inducer region with at least one inducer blade extending radially inward from the stator near the inlet without spanning the cavity; and a diffuser region with at least one diffuser blade extending inward from the stator near the outlet without spanning the cavity.