Blood pump with improved leakage control

Abstract

A blood pump with a stator and rotor wherein the rotor is assembled by bonding the stator components with epoxy. The bonding surfaces of the rotor components are primed with a silane-based primer to improve adhesion between the primer and the rotor components by rendering such surfaces hydrophobic. A bonding surface of one of the stator yoke or the stator sleeve, or both, is treated with a primer that improves wettability of the bonding surface and improves bonding of the epoxy to the binding surface. The device has a bonding surface adhered to epoxy in which a primer was applied on such bonding surface prior to introducing epoxy onto the bonding surface. In addition to improved bond strength, hydrophobic surface would control moister ingress.

We claim: 
     
         1 . A blood pump, comprising:
 a pump motor comprising a rotor portion having proximal and distal ends and a stator portion having proximal and distal ends, wherein the proximal portion of the rotor portion is received into a cavity defined by the stator portion;   the rotor portion comprising an impeller, wherein the impeller comprises impeller blades and a drive unit, the impeller blades positioned at the distal end of the rotor portion and not received into the stator and the drive unit positioned in a portion of the rotor received into the stator portion, wherein the drive unit is coupled to the impeller blades;   the stator portion comprising a yoke, a coil and a coil holding sleeve, the sleeve defining the cavity into which the proximal portion of the rotor is received;   wherein the yoke, coil and sleeve have interior and exterior surfaces, wherein epoxy is introduced between the yoke and the coil and the coil and the sleeve, thereby substantially embedding the coil in epoxy, wherein at least one of the interior surface of the yoke, the exterior surface of the coil, the interior surface of the coil or the exterior surface of the sleeve are treated with a primer prior to the introduction of epoxy therebetween.   
     
     
         2 . The blood pump of  claim 1  wherein the primer is a silane solution. 
     
     
         3 . The blood pump of  claim 2  wherein the silane has the general chemical formula (RO) 3 SiCH 2 CH 2 CH 2 —X wherein RO is a hydrolysable group. 
     
     
         4 . The blood pump of  claim 3  wherein the hydrolysable group is selected from the group consisting of methoxy, ethoxy, or acetoxy. 
     
     
         5 . The blood pump of  claim 4  wherein X is an organofunctional group. 
     
     
         6 . The blood pump of  claim 1  wherein the interior surface of the yoke is treated with the primer wherein the primer is a silane solution such that the silane is interposed between the interior surface of the yoke and the epoxy. 
     
     
         7 . The blood pump of  claim 1  wherein exterior surface of the coil is treated with the primer wherein the primer is a silane solution such that the silane is interposed between the exterior surface of the coil and the epoxy. 
     
     
         8 . The blood pump of  claim 1  wherein the interior surface of the coil is treated with the primer wherein the primer is a silane solution such that the silane is interposed between the interior surface of the coil and the epoxy. 
     
     
         9 . The blood pump of  claim 1  wherein the exterior surface of the sleeve is treated with the primer wherein the primer is a silane solution such that the silane is interposed between the exterior surface of the sleeve and the epoxy. 
     
     
         10 . A method for making a blood pump the method comprising:
 assembling a pump motor comprising a rotor portion having proximal and distal ends and a stator portion having proximal and distal ends, wherein the proximal portion of the rotor portion is received into a cavity defined by the stator portion;   the rotor portion comprising an impeller, wherein the impeller comprises impeller blades and a drive unit, the impeller blades positioned at the distal end of the rotor portion and not received into the stator and the drive unit positioned in a portion of the rotor received into the stator portion, wherein the drive unit is coupled to the impeller blades;   the stator portion comprising a yoke, a coil and a coil holding sleeve, the sleeve defining the cavity into which the proximal portion of the rotor is received;   wherein the yoke, coil and sleeve have interior and exterior surfaces;   treating at least one of the interior surface of the yoke, the exterior surface of the coil, the interior surface of the coil or the exterior surface of the sleeve with a primer; and   introducing epoxy between the yoke and the coil and the coil and the sleeve, thereby substantially embedding the coil in epoxy.   
     
     
         11 . The method of  claim 1  wherein the primer is a silane solution. 
     
     
         12 . The method of  claim 11  wherein the silane has the general chemical formula (RO) 3 SiCH 2 CH 2 CH 2 —X wherein RO is a hydrolysable group. 
     
     
         13 . The method of  claim 12  wherein the hydrolysable group is selected from the group consisting of methoxy, ethoxy, or acetoxy. 
     
     
         14 . The method of  claim 13  wherein X is an organofunctional group. 
     
     
         15 . The method of  claim 10  wherein the interior surface of the yoke is treated with the primer wherein the primer is a silane solution such that the silane is coated on the interior surface of the yoke when the epoxy is introduced between the yoke and the coil. 
     
     
         16 . The method of  claim 10  wherein exterior surface of the coil is treated with the primer wherein the primer is a silane solution such that the silane is coated on the exterior surface of the coil when the epoxy is introduced between the yoke and the coil. 
     
     
         17 . The method of  claim 10  wherein the interior surface of the coil is treated with the primer wherein the primer is a silane solution such that the silane is coated on the interior surface of the coil when the epoxy is introduced between the coil and the sleeve. 
     
     
         18 . The blood pump of  claim 10  wherein the exterior surface of the sleeve is treated with the primer wherein the primer is a silane solution such that the silane is coated on the exterior surface of the sleeve when the epoxy is introduced between the coil and the sleeve.