BLOOD PUMP HAVING A MAGNETICALLY SUSPENDED ROTOR

摘要

A blood pump (500) preferably has a magnetically suspended rotor (502) that rotates within a housing (506). The rotor (502) may rotate about a stator (504) disposed within the housing. Radial magnetic bearings (560) may be defined within a stator (504) and a rotor (502) in order to suspend the rotor (502). The radial magnetic bearings (560) may be passive magnetic bearings that include permanent magnets disposed within the stator and the rotor or active magnetic bearings. The pump (500) may further include an axial magnetic bearing (562) that may be either a passive or an active magnetic bearing. A motor stator (508) that drives the rotor may be disposed within the housing in order to more easily dissipate heat generated by the motor stator (508). A primary flow path (552) is defined between the stator (504) and the rotor (502), and a secondary flow path (552) is defined between the stator (504) and the rotor (502). Preferably, a substantial majority of blood passes through the primary flow path (550). The secondary flow path (552) is large enough so that it provides adequate flushing of the secondary flow path (552) while being small enough to permit efficient operation of the radial magnet bearings (560) across the secondary path (552).