Catheter pump

Abstract

A catheter pump is provided that includes a rotatable impeller and an elongate cannula. The elongate cannula has a mesh that has a plurality of circumferential members disposed about the impeller. The elongate cannula has a plurality of axial connector extending between a proximal side of a distal circumferential member and a distal side of a proximal circumferential member. The circumferential members are radially self-expandable. The cannula is configured to minimize fracture within at least in the distal zone of the mesh as the elongated cannula moves into a sheathing device.

What is claimed is: 
     
         1 . A catheter pump assembly, comprising:
 an elongate body having a distal end and a proximal end opposite the distal end;   an expandable cannula coupled with the distal end of the elongate body, the expandable cannula comprising:
 a mesh structure that includes a plurality of nitinol members defining a cannula distal portion and a cannula proximal portion, the cannula proximal portion tapering from an expanded diameter to a smaller diameter at the distal end of the elongate body and coupled to the distal end of the elongate body, the cannula distal portion defining a plurality of inlet spaces between the plurality of nitinol members to permit blood to enter the expandable cannula; and 
 a coating formed over the mesh structure and forming a conduit for the flow of blood from the cannula distal portion to the cannula proximal portion; and 
   an impeller coupled with the distal end of the elongate body, the impeller configured to rotate to induce blood flow through the expandable cannula.   
     
     
         2 . The catheter pump assembly of  claim 1 , wherein the expanded diameter is at least 5 millimeters. 
     
     
         3 . The catheter pump assembly of  claim 1 , wherein the cannula proximal portion tapers at an angle in the range of 30 degrees to 40 degrees relative to the longitudinal axis of the elongate body. 
     
     
         4 . The catheter pump assembly of  claim 1 , wherein the expandable cannula is configured to collapse to a delivery configuration having a delivery diameter for insertion into a patient, and expand to the expanded diameter for operation. 
     
     
         5 . The catheter pump assembly of  claim 1 , wherein the coating comprises a biocompatible polymer. 
     
     
         6 . The catheter pump assembly of  claim 1 , wherein the plurality of nitinol members forms connection structures for securing the mesh structure to the elongate body. 
     
     
         7 . The catheter pump assembly of  claim 6 , wherein the connection structures secure the mesh structure to the elongate body at a hub structure. 
     
     
         8 . The catheter pump assembly of  claim 7 , wherein the connection structures engage slots formed in the hub structure. 
     
     
         9 . The catheter pump assembly of  claim 6 , wherein the connection structures comprise loop elements. 
     
     
         10 . The catheter pump assembly of  claim 6 , wherein the connection structures comprise linear elements. 
     
     
         11 . A cannula comprising:
 a self-expandable mesh structure having a proximal portion and a distal portion, the mesh structure comprising:
 a plurality of struts, each strut of the plurality of struts disposed adjacent at least one other strut and spaced apart axially from the least one other adjacent strut, the plurality of struts extending at least partway between the proximal portion of the mesh structure and the distal portion of the mesh structure, the proximal portion tapering from an expanded diameter to a smaller diameter and configured to be coupled to a distal end of a catheter body, the distal portion defining a plurality of inlet spaces between the plurality of struts to permit blood to enter the self-expandable mesh structure; and 
 a polymeric enclosure disposed about at least a portion of the mesh structure to define a lumen along a length of the mesh structure from the proximal portion to the distal portion. 
   
     
     
         12 . The cannula of  claim 11 , wherein the expanded diameter is at least 5 millimeters. 
     
     
         13 . The cannula of  claim 11 , wherein the cannula proximal portion tapers at an angle in the range of 30 degrees to 40 degrees relative to the longitudinal axis of the elongate body. 
     
     
         14 . The cannula of  claim 11 , wherein the expandable cannula is configured to collapse to a delivery configuration having a delivery diameter for insertion into a patient, and expand to the expanded diameter for operation. 
     
     
         15 . The cannula of  claim 11 , wherein the coating comprises a biocompatible polymer. 
     
     
         16 . The cannula of  claim 11 , wherein the plurality of nitinol members forms connection structures for securing the mesh structure to the elongate body. 
     
     
         17 . The cannula of  claim 16 , wherein the connection structures secure the mesh structure to the elongate body at a hub structure. 
     
     
         18 . The cannula of  claim 17 , wherein the connection structures engage slots formed in the hub structure. 
     
     
         19 . The cannula of  claim 16 , wherein the connection structures comprise loop elements. 
     
     
         20 . The cannula of  claim 16 , wherein the connection structures comprise linear elements.