Axial flow blood pump with hydrodynamically suspended rotor

An axial flow blood pump for pumping blood through a patient's bloodstream comprising:

• a cylindrical conduit adapted to be disposed in the bloodstream of the patient, the conduit having an internal surface defining a central axial passageway for blood passage therethrough, the passageway having an inner diameter;
• a pump stator mounted within the conduit, the pump stator including axially displaced inlet and outlet sections and a hub extending along the conduit therebetween;
• a cylindrical motor stator located externally of the passageway through the conduit so as to be out of contact with the blood flowing therethrough, the motor stator having windings and a control circuit to create flux in the conduit between he inlet and outlet pump stator sections, said motor stator located externally of said conduit;
• a cylindrical rotor axially positioned in the conduit between the inlet and outlet stator sections, the cylindrical rotor having an outer surface with an outer diameter less than said conduit inner diameter, thereby to define an outer annular radial gap between said rotor outer surface and said conduit internal surface when the rotor is radially centered in the conduit, the rotor further including,
• a plurality of impeller blades extending radially inwardly toward said pump stator hub and defining an inner annular gap therebetween,
• at least one permanent magnet located radially outside of said impeller blades and adapted to interact with said applied flux to rotate the rotor to produce axial blood flow through the passageway from the inlet stator section to the outlet stator section;
• whereby, during rotor rotation, the rotor is suspended radially inside the conduit so as to float on the blood and this result is achieved solely by hydrodynamic effects created by the presence of said blood flowing through said outer an inner annular gaps, respectively.

An axial flow blood pump for pumping blood through a patient's bloodstream comprising:

• a cylindrical conduit adapted to be disposed in the bloodstream of the patient, the conduit having an internal surface defining a central axial passageway for blood passage therethrough, the passageway having an inner diameter;
• a pump stator mounted within the conduit, the pump stator including axially displaced inlet and outlet sections and a hub extending along the conduit therebetween;
• a motor stator having windings and a control circuit to create flux in the conduit between the inlet and outlet pump stator sections, said motor stator located radially within said pump stator hub and axially between said inlet and outlet sections;
• a cylindrical rotor axially positioned in the conduit between the inlet and outlet stator sections and circumscribing said motor stator, the rotor further including,
• a plurality of impeller blades, the cylindrical rotor having an inner diameter greater than said pump stator and an outer diameter less than said conduit inner diameter, thereby to define an inner annular radial gap between said rotor and said pump stator and an outer annular radial gap between said rotor and said conduit internal surface when the rotor is radially centered in the conduit,
• at least one permanent magnet adapted to interact with said applied flux to rotate the rotor to produce axial blood flow through the passageway from the inlet stator section to the outlet stator section;
• whereby, during rotor rotation, the rotor is suspended radially inside the conduit so as to float on the blood and this result is achieved solely by hydrodynamic effects created by the presence of said blood flowing through said outer an inner annular gaps, respectively.

An axial flow blood pump for pumping blood through a patient's bloodstream comprising:

• a cylindrical conduit adapted to be disposed in the bloodstream of the patient, the conduit having an internal surface defining a central axial passageway for blood passage therethrough, the passageway having an inner diameter;
• a pump stator mounted within the conduit, the pump stator including axially displaced inlet and outlet sections;
• a motor stator having windings and a control circuit to create flux in the conduit between the inlet and outlet pump stator sections, said motor stator located outside of said conduit;
• a noncylindrical rotor axially positioned in the conduit between the inlet and outlet stator sections and aligned along a central axis through said conduit, the rotor further including,
• a plurality of impeller blades extending radially outwardly therefrom, the rotor having an outer diameter less than said conduit inner diameter, thereby to define an outer annular radial gap between the rotor and the conduit internal surface when the rotor is radially centered in the conduit,
• at least one permanent magnet located radially inside of said impeller blades and adapted to interact with said applied flux to rotate the rotor to produce axial blood flow through the passageway from the inlet stator section to the outlet stator section;
• whereby, during rotor rotation, the rotor is suspended radially inside the conduit so as to float on the blood and this result is achieved solely by a hydrodynamic effect created by the presence of said blood flowing around said rotor and through said gap.