Centrifugal blood pump assembly

DETAILED DESCRIPTION According to a first aspect of the invention, there is provided 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 rotatable in the housing for feeding blood by a centrifugal force developed during rotation; a controlled magnetic bearing means for magnetically supporting the impeller; and an uncontrolled magnetic bearing means for magnetically supporting the impeller.
The controlled magnetic bearing means and the uncontrolled magnetic bearing means cooperate such that the impeller rotates while it is held at a predetermined position within the housing.
The impeller is rotatable even when the controlled magnetic bearing means is inoperative and the uncontrolled magnetic bearing means is operative.
During rotation of the impeller, a blood flowpath is defined between a surface of the impeller on the side of the uncontrolled magnetic bearing means and an inner surface of the housing facing the impeller surface.
According to a second aspect of the invention, there is provided 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 the impeller; and an uncontrolled magnetic bearing means for magnetically supporting the impeller.
The controlled magnetic bearing means and the uncontrolled magnetic bearing means cooperate such that the impeller rotates while it is held at a predetermined position within the housing.
The impeller is rotatable even when the controlled magnetic bearing means is inoperative and the uncontrolled magnetic bearing means is operative.
The 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 the impeller facing the uncontrolled magnetic bearing means, the beveled edge increasing its diameter toward the uncontrolled magnetic bearing means