Centrifugal blood pump assembly

A centrifugal blood pump assembly comprising

• a centrifugal blood pump comprising a housing having an inlet port and an outlet port for blood and adapted to receive blood therein, and an impeller adapted to rotate within the housing for feeding blood by a centrifugal force developed during rotation,
• a controlled magnetic bearing means for magnetically supporting said impeller, and
• an uncontrolled magnetic bearing means for magnetically supporting said impeller, wherein
• said controlled magnetic bearing means and said uncontrolled magnetic bearing means cooperate such that said impeller rotates while it is held at a predetermined position within said housing,
• said impeller is rotatable even when said controlled magnetic bearing means is inoperative and said uncontrolled magnetic bearing means is operative,
• said impeller includes an opening extending through the impeller at the center and a beveled edge at the crossing of the opening with the surface of said impeller facing said uncontrolled magnetic bearing means, the beveled edge increasing its diameter toward said uncontrolled magnetic bearing means, and
• said housing includes a raised portion formed on said inner surface at a position corresponding to the opening of said impeller, the raised portion having a tapered side surface which comes in contact with the beveled edge of said impeller when said controlled magnetic bearing means is inoperative.

A centrifugal blood pump assembly comprising

• a centrifugal blood pump comprising a blood pump housing having an inlet port and an outlet port for blood and adapted to receive blood therein, and an impeller adapted to rotate within the housing for feeding blood by a centrifugal force developed during rotation,
• an impeller position control unit for magnetically supporting said impeller including a control unit housing separable from said blood pump housing, an electromagnet positioned in the control unit housing and a position sensor positioned in the control unit housing, and
• an impeller rotation torque generating unit including a torque generating unit housing separable from the blood pump housing and an impeller rotation torque generating mechanism in the torque generating unit housing, wherein
• said impeller position control unit and the impeller rotation torque generating unit cooperate such that said impeller rotates while it is held at a predetermined position within said blood pump housing, and
• said impeller position control unit and the impeller rotation torque generating unit are removably mounted to said centrifugal blood pump.