A high efficiency blood pump includes a pump housing, wherein the pump housing provides an inlet and outlet. The pump includes a motor housing, wherein the motor housing contains a motor. An impeller is housed in the pump housing, wherein the impeller is radially supported by a hydrodynamic bearing providing at least one row of pattern grooves. A diaphragm provided by the pump housing separates the impeller chamber from the motor chamber. A magnetic coupling is provided between the motor and the impeller, wherein the magnetic coupling causes the impeller to rotate when the motor rotates and provides axial restraint of the impeller.
