Rotary blood pump

Abstract

A rotary blood pump comprises a housing and a rotor. The housing includes a blood inlet, a blood outlet, a blood flow conduit disposed between the blood inlet and the blood outlet, and a rotary bearing assembly disposed within and fixed to the housing. The rotor is rotatably disposed within the housing and includes one or more impellor blades disposed within the blood flow conduit for pumping blood through the conduit, and a shaft affixed to and rotating with the rotor. The shaft rotatably engages the bearing assembly to define an intersection between the rotor and the housing and to provide relative rotation between the rotor and the housing. In addition, the shaft further defines an axis of rotation for the rotor. In the rotary pump of the invention, at least one of the rotor and the housing defines a swirl region proximate to the intersection between the rotor and the housing. The swirl region includes a curved surface adapted to cause blood being pumped through the blood flow conduit to swirl about an axis that is transverse to and spaced apart from the axis of rotation of the rotor. This swirl washes the intersection between the housing and the rotor, and further provides blood flow in a region that would otherwise have low flow.

Dependencies are inferred from the claim text.