Axial flow blood pump

A blood pump comprising:

• a housing comprising an inner wall surface defining an inlet, an outlet downstream from the inlet, and a blood flow channel between the inlet and the outlet, wherein a first portion of the inner wall surface has a first inner dimension that increases to a second inner dimension in a downstream direction;
• an axial flow impeller positioned within the blood flow channel downstream of the first portion of the inner wall surface and rotatable within the blood flow channel to pump an axial blood flow along the blood flow channel, the axial flow impeller comprising a magnetic material and at least one hydrodynamic thrust bearing surface having an outer dimension that is greater than the first inner dimension of the inner wall surface such that blood flowing between the first portion of the inner wall surface and the at least one hydrodynamic thrust bearing surface applies a pressure to the at least one hydrodynamic thrust bearing surface and prevents the axial flow impeller from advancing upstream of the first portion of the inner wall surface;
• a motor stator positioned about the blood flow channel between the inlet and the outlet, wherein the motor stator is configured to generate a magnetic field for suspending and rotating the axial flow impeller within the blood flow channel;
• and
• wherein the magnetic field generated by the motor stator is configured to bias the axial flow impeller such that the magnetic field urges the axial flow impeller in an upstream direction toward the first portion of the inner wall surface to stabilize the axial flow impeller in an axial direction.