A bearingless and sealless rotary blood pump is disclosed which provides multidirectional flow intended to provide low-pressure, high-volume right-sided partial assist circulatory support in a univentricular Fontan circulation on a permanent basis. The pump includes a housing and an impeller suspended in the center of the housing. The housing incorporates flow optimization features between inlet and outlet ends, as well as with the impeller surface. Large fluid gaps maintained between impeller and housing eliminate any potential for blood flow obstruction. The impeller contains some motor components. It includes a central stator and surrounding rotor. The motor includes a brushless DC outrunner electrical motor design. An electromagnetic stator core is surrounded by a circumferential passive magnetic ring. The rotor is further levitated about the stator spindle by a plurality of axially and radially located passive magnetic and hydrodynamic journal bearings on both ends of the spindle. The rotor is bearingless and sealless. During impeller rotation, blood entering the space between the rotor and stator is induced to flow by centrifugal pumping action and the fluid film separates the stator hydrodynamic bearings from the rotor so that there is no direct mechanical contact between the rotor and stator.
