High efficiency blood pump

Abstract

A high efficiency blood pump includes a pump housing, wherein the pump housing provides an inlet and outlet. The pump includes a motor housing, wherein the motor housing contains a motor. An impeller is housed in the pump housing, wherein the impeller is radially supported by a hydrodynamic bearing providing at least one row of pattern grooves. A diaphragm provided by the pump housing separates the impeller chamber from the motor chamber. A magnetic coupling is provided between the motor and the impeller, wherein the magnetic coupling causes the impeller to rotate when the motor rotates and provides axial restraint of the impeller.

1 - 35 . (canceled) 
     
     
         36 . A blood pump comprising:
 a pump housing, wherein the pump housing provides an inlet and outlet;   a cylindrical bearing surface facing radially outward from a central axis and housing a hub configured to rotate about the central axis and the hub comprising a first permanent magnet;   an impeller housed in the pump housing configured to rotate concentrically with respect to the cylindrical bearing surface and comprising (i) a bore receiving the cylindrical bearing surface and defining an internal surface concentric with the central axis, a first hydrodynamic bearing configured to radially support the impeller and being provided between the cylindrical bearing surface and the internal surface; (ii) a multi-lobe shape on the internal surface forming the first hydrodynamic bearing; (iii) a second permanent magnet axially aligned with and radially displaced from the first permanent magnet of the hub, the first permanent magnet and the second permanent magnet forming a magnetic coupling; and   a motor axially displaced from and rotationally connected to the hub.   
     
     
         37 . The blood pump of  claim 36 , further comprising a non-ferromagnetic diaphragm provided by the pump housing, wherein the impeller is configured to rotate concentrically around the diaphragm, and the diaphragm is intermediate to the magnetic coupling between the motor and the impeller. 
     
     
         38 . The blood pump of  claim 36 , further comprising:
 an impeller chamber defined by the pump housing, wherein the impeller is housed in the impeller chamber;   a motor housing defining a motor chamber, wherein the motor is housed in the motor chamber; and   a diaphragm provided by the pump housing and the diaphragm separates the motor chamber and the impeller chamber.   
     
     
         39 . The blood pump of  claim 36 , wherein the impeller is configured to create high pressure zones, when the impeller is rotating, between the internal surface of the impeller and the cylindrical bearing surface. 
     
     
         40 . The blood pump of  claim 36 , wherein the multi-lobe shape is configured to create, when the impeller is rotating, high pressure zones within the first hydrodynamic bearing, such that the impeller, when rotating concentrically with respect to the cylindrical bearing surface, is stabilized by radial stabilizing forces created by the high pressure zones. 
     
     
         41 . The blood pump of  claim 36 , wherein the motor is a brushless DC motor having an efficiency equal to 85% or greater. 
     
     
         42 . The blood pump of  claim 36 , wherein top surfaces of the impeller provide a second hydrodynamic bearing that provides a top set of pattern grooves for axial support of the impeller. 
     
     
         43 . The blood pump of  claim 42 , wherein the grooves of the top set are spiral grooves or spiral herringbone grooves. 
     
     
         44 . The blood pump of  claim 42 , wherein the grooves of the top set are rectangular, rectangular with a bevel, semi-circular, or elliptical in cross section. 
     
     
         45 . The blood pump of  claim 36 , further comprising a passive magnetic axial bearing. 
     
     
         46 . The blood pump of  claim 45 , wherein the passive magnetic axial bearing comprises:
 a first set of one or more permanent magnets, wherein the first set of permanent magnets is housed in blades of the impeller and configured to rotate with the impeller;   a second set of one or more permanent magnets, wherein the second set of permanent magnets is housed above the impeller in and fixed relative to the pump housing; and   a third set of one or more permanent magnets, wherein the third set of permanent magnets is housed below the impeller in and fixed relative to the pump housing.   
     
     
         47 . A blood pump comprising:
 a pump housing, wherein the pump housing provides an inlet and outlet;   an impeller chamber defined by the pump housing, wherein an impeller is housed in the impeller chamber;   a motor housing defining a motor chamber, wherein a motor is housed in the motor chamber; wherein the motor provides a shaft with a hub mounted to the shaft; wherein the hub comprises a first permanent magnet;   a diaphragm provided by the pump housing, the diaphragm separating the motor chamber and the impeller chamber; the diaphragm defines cavity providing a region for hub to rotate within; diaphragm also provides a cylindrical bearing surface for impeller to rotate around with hydrodynamic radial support;   wherein the impeller is radially supported by a first hydrodynamic bearing between the cylindrical bearing surface and an impeller internal surface that provides a multi-lobe shape on the internal surface, the multi-lobe shape being configured to create the first hydrodynamic bearing and provide radial hydrodynamic support to cause the impeller to rotate concentrically about the cylindrical bearing surface, the impeller further comprising a second permanent magnet providing a magnetic coupling between the impeller and the hub.   
     
     
         48 . The blood pump of  claim 47 ,
 wherein the magnetic coupling causes the impeller to rotate when the motor rotates, and the diaphragm is a non-ferromagnetic diaphragm.   
     
     
         49 . The blood pump of  claim 47 , wherein the impeller is an open pressure balanced type impeller that minimizes axial thrust during operation of the pump. 
     
     
         50 . The blood pump of  claim 47 , wherein top surfaces of the impeller provide a second hydrodynamic bearing that provides a top set of pattern grooves for axial support of the impeller; optionally wherein the top set of pattern grooves are spiral grooves or spiral herringbone grooves; or wherein the top set of pattern grooves are rectangular, rectangular with a bevel, semi-circular, or elliptical in cross section. 
     
     
         51 . The blood pump of  claim 47 , wherein at least a portion of the impeller is conically shaped. 
     
     
         52 . The blood pump of  claim 51 , wherein top surfaces of the impeller are linear, convex, or concave. 
     
     
         53 . The blood pump of  claim 51 , wherein top surfaces of the impeller provide a top set of pattern grooves for axial and radial support of the impeller; optionally wherein the top set of pattern grooves are spiral grooves or spiral herringbone grooves; or wherein the top set of pattern grooves are rectangular, rectangular with a bevel, semi-circular, or elliptical in cross section. 
     
     
         54 . The blood pump of  claim 47 , further comprising a passive magnetic axial bearing comprising:
 a first set of one or more permanent magnets, wherein the first set of permanent magnets is housed in the impeller;   a second set of one or more permanent magnets, wherein the second set of permanent magnets is housed above the impeller in the pump housing; and   a third set of one or more permanent magnets, wherein the third set of permanent magnets is housed below the impeller in the pump housing.   
     
     
         55 . The blood pump of  claim 47 , wherein the impeller is configured to create a high pressure zone, when the impeller is rotating, between the impeller internal surface and the cylindrical bearing surface.