Axial flow pump with multi-grooved rotor

An axial-flow blood pump for pumping blood, comprising:

• a substantially cylindrical outer enclosure;
• a tubular housing concentric with and located within said outer enclosure having at one end an inlet and at an opposite end an outlet;
• a motor stator concentric with and located between said outer enclosure and said tubular housing;
• an impeller concentric with and located within said tubular housing, suspended in operation by a combination of passive magnetic forces between magnets within said impeller or magnetized regions of said impeller and said motor stator and hydrodynamic thrust forces generated as blood flows between said tubular housing and a plurality of hydrodynamic thrust bearing surfaces located on said impeller;
• and
• a volute in fluid-tight connection with said outlet of said tubular housing for receiving blood in the axial direction and directing blood in a direction normal to the axial direction, wherein said volute has a flow-improving member extending axially from the volute and into and coaxially with said tubular housing.

An axial-flow blood pump for pumping blood, comprising:

• a substantially cylindrical outer enclosure;
• a tubular housing concentric with and located within said outer enclosure having at one end an inlet and at an opposite end an outlet;
• a motor stator concentric with and located between said outer enclosure and said tubular housing;
• an impeller concentric with and located within said tubular housing, suspended in operation by a combination of passive magnetic forces between magnets within said impeller or magnetized regions of said impeller and said motor stator and hydrodynamic thrust forces generated as blood flows between said tubular housing and a plurality of hydrodynamic thrust bearing surfaces located on said impeller, and
• a flow straightener or diffuser in fluid-tight connection with said outlet of said tubular housing for receiving blood in the axial direction and directing blood in said axial direction or in a direction normal to the axial direction, wherein said flow straightener has one or more stator blades therein.