Sheath system for catheter pump

Abstract

A catheter pump assembly is provided. The catheter pump assembly includes a proximal portion, a distal portion, a catheter body having a lumen extending along a longitudinal axis between the proximal and distal portions, an impeller disposed at the distal portion, and a stator disposed at a downstream location of the impeller to straighten flow downstream from the impeller. The stator is collapsible from a deployed configuration to a collapsed configuration.

1 . A catheter pump assembly, comprising:
 a proximal portion;   a distal portion;   a catheter body having a lumen extending along a longitudinal axis between the proximal and distal portions;   an impeller disposed at the distal portion; and   a stator disposed at a downstream location of the impeller to straighten flow downstream from the impeller;   wherein the stator is collapsible from a deployed configuration to a collapsed configuration.   
     
     
         2 . The catheter pump assembly of  claim 1 , wherein the stator is collapsible to a smaller diameter for percutaneous insertion. 
     
     
         3 . The catheter pump assembly of  claim 1 , wherein the stator is collapsible to a smaller diameter for insertion into a femoral artery. 
     
     
         4 . The catheter pump assembly of  claim 1 , further comprising a bearing assembly disposed proximal of the impeller, the stator being disposed on a distal projection of the bearing assembly. 
     
     
         5 . The catheter pump assembly of  claim 4 , wherein a mechanical interface is provided between the bearing assembly projection and the stator, the mechanical interface further comprising a distal facing radial shoulder adjacent to a proximal facing end of the stator. 
     
     
         6 . The catheter pump assembly of  claim 4 , wherein a mechanical interface is provided between the bearing assembly projection and the stator, the mechanical interface further comprising mating features disposed on the outer surface of the projection and on an inner surface of a lumen extending through a central body of the stator. 
     
     
         7 . The catheter pump assembly of  claim 6 , wherein the mating features comprise helical grooves and projections. 
     
     
         8 . The catheter pump assembly of  claim 7 , wherein the grooves and projections are configured to tighten engagement between the bearing assembly projection and the stator upon application of torque by fluid flow generated by the impeller. 
     
     
         9 . The catheter pump assembly of  claim 1 , wherein the stator is disposed proximal of the impeller in a percutaneous left ventricle application. 
     
     
         10 . The catheter pump assembly of  claim 1 , wherein the stator is disposed distal of the impeller in a percutaneous right ventricle application. 
     
     
         11 . The catheter pump assembly of  claim 1 , wherein the stator is disposed distal of the impeller in a transapical approach to aid the left ventricle. 
     
     
         12 . The catheter pump assembly of  claim 1 , wherein the stator comprises stator blades oriented in an opposite direction to an orientation of blades of the impeller. 
     
     
         13 . The catheter pump assembly of  claim 1 , wherein a gap is disposed between the stator and the impeller, the gap separating the stator and the impeller. 
     
     
         14 . The catheter pump assembly of  claim 1 , further comprising an elongate sheath body, wherein the sheath body is configured to apply force to the catheter body, the impeller, and the stator to facilitate collapsing of a deployed working end. 
     
     
         15 . A catheter system, comprising:
 an elongate polymeric catheter body comprising a proximal end and a distal end;   a cannula having an expandable portion disposed distally of the elongate polymeric catheter body;   at least one expandable component disposed within the cannula; and   an elongate sheath body having a retracted position in which the elongate sheath body is proximal of the expandable portion of the cannula and the at least one expandable component and a forward position in which the elongate sheath body is disposed over the expandable portion of the cannula and the at least one expandable component;   wherein a first segment of the elongate sheath body disposed over the expandable portion of the cannula and the at least one expandable component is configured to resist kinking to a greater extent than a second segment of the elongate sheath body disposed adjacent to the first segment.   
     
     
         16 . The catheter system of  claim 15 , wherein the first segment has a higher hardness than the second segment. 
     
     
         17 . The catheter system of  claim 15 , further comprising a stator disposed at a downstream location of the at least one expandable component to straighten flow downstream from the at least one expandable component, wherein the sheath body is configured to apply force to the catheter body, the cannula, the at least one expandable component, and the stator to facilitate collapsing of a deployed working end.