Implantable centrifugal blood pump with hybrid magnetic bearings

Abstract

A pump for pumping sensitive fluids, such as blood, has no mechanical contact between the impeller and any other structure.

1 . An apparatus for pumping sensitive biological fluids, comprising:
 a construct having an exterior, an interior having walls therein, at least one housing magnet disposed therein, and an axial center;   an inlet permitting passage of fluids through the construct and into the interior of the construct;   an outlet permitting passage of fluids through the construct from the interior of the construct, the outlet radially located from the axial center of the construct;   an impeller disposed within the interior of the construct and out of contact with the construct;   a magnetic system including at least one impeller magnet juxtaposed to the housing magnet, which is magnetized in a direction for suspending the impeller out of contact with the construct; and   a motor to drive the impeller and control fluid flowing through the apparatus.   
     
     
         2 . The apparatus of  claim 1 , wherein the impeller includes arcuate blades and arcuate passageways whereby fluid flow through the construct is redirected from the inlet to the outlet. 
     
     
         3 . The apparatus of  claim 2 , wherein the magnetic system comprises:
 a first construct permanent magnet disposed on a first wall of the interior of the construct; a second construct permanent magnet disposed on a second wall, opposite the first wall, of the interior of the construct;   a first impeller permanent magnet disposed on the impeller distal to the axial center of the construct and juxtaposed with the first construct permanent magnet; a second impeller permanent magnet disposed on the impeller distal to the axial center of the construct and juxtaposed with the second construct permanent magnet;   a first construct permanent magnet set disposed on the first wall of the interior of the construct;   a second construct permanent magnet set disposed on the second wall of the interior of the construct;   a first impeller permanent magnet set disposed on the impeller proximate to the axial center of the construct and juxtaposed with the first construct permanent magnet set; and   a second impeller permanent magnet set disposed on the impeller proximate to the axial center of the construct and juxtaposed with the second construct permanent magnet set;   wherein the arrangement provides radial stabilization and, due to angular positioning, provides a degree of translational stabilization of the impeller and the impeller is prevented from contacting the interior of the construct by magnetic fields.   
     
     
         4 . The apparatus of  claim 3 , wherein the inlet is integral with the construct exterior. 
     
     
         5 . The apparatus of  claim 3 , wherein the outlet is integral with the construct exterior. 
     
     
         6 . The apparatus of  claim 3 , wherein the outlet is radially located from the axial center of the construct.