Ventricular assist device

Abstract

Apparatus and methods are described including a left-ventricular assist device that includes an impeller (50) and a frame (34) disposed around the impeller (50). The frame (34) includes strut junctions (33) at a proximal end of the frame, the strut junctions (33) being configured to be maintained in open states, during assembly of the left ventricular assist device, to facilitate insertion of the impeller (50) into the frame (34). A securing element (117) holds the struts junctions in closed states, subsequent to the insertion of the impeller (50) into the frame (34). A pump-outlet tube (24) extends to a distal end of the frame (34) and defines one or more lateral blood inlet openings (108) that are configured to allow blood to flow from the subject's left ventricle into the pump-outlet tube (24). Other applications are also described.

1 . An apparatus comprising:
 a left-ventricular assist device comprising:
 an impeller configured to be placed inside a left ventricle of a subject and to pump blood from the left ventricle to an aorta of the subject, by rotating; 
 a frame disposed around the impeller, the frame comprising a plurality of strut junctions at a proximal end of the frame, the strut junctions being configured to be maintained in open states, during assembly of the left ventricular assist device, to facilitate insertion of the impeller into the frame; 
 a securing element configured to hold the struts junctions in closed states, subsequent to the insertion of the impeller into the frame; and 
 a pump-outlet tube configured to traverse an aortic valve of the subject, such that a proximal portion of the pump-outlet tube is disposed within the subject's aorta and a distal portion of the pump-outlet tube is disposed within the subject's left ventricle, the distal portion of the pump-outlet tube extending to a distal end of the frame and defining one or more lateral blood inlet openings that are configured to allow blood to flow from the subject's left ventricle into the pump-outlet tube. 
   
     
     
         2 . The apparatus according to  claim 1 , wherein the securing element comprises a ring. 
     
     
         3 . The apparatus according to  claim 1 , wherein the left-ventricular assist device comprises a portion that is distal to the frame, and wherein the pump-outlet tube further comprises a coupling portion that extends distally from the frame and that is coupled to the portion of the left-ventricular assist device that is distal the frame. 
     
     
         4 . The apparatus according to  claim 1 , wherein the distal portion of the pump-outlet tube defines more than 10 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame. 
     
     
         5 . The apparatus according to  claim 4 , wherein the distal portion of the pump-outlet tube defines more than 50 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame. 
     
     
         6 . The apparatus according to  claim 1 , wherein the left-ventricular assist device further comprises:
 a proximal radial bearing disposed within a proximal bearing housing at a proximal end of the frame;   a distal radial bearing disposed within a distal bearing housing at a distal end of the frame;   an axial shaft upon which the impeller is disposed, the axial shaft passing through the proximal radial bearing and the distal radial bearing,   wherein the securing element is configured to hold the struts junctions closed around an outer surface of the proximal bearing housing.   
     
     
         7 . The apparatus according to  claim 6 , wherein the pump-outlet tube further comprises a coupling portion that extends distally from the frame and that is coupled to the distal bearing housing. 
     
     
         8 . The apparatus according to  claim 6 , wherein a distal end of the frame is coupled to an outer surface of the distal bearing housing. 
     
     
         9 . The apparatus according to  claim 6 , wherein the left-ventricular assist device further comprises a distal tip element, and wherein the distal tip element is coupled to the distal bearing housing. 
     
     
         10 . The apparatus according to  claim 6 , wherein the outer surface of the proximal bearing housing defines grooves that are shaped to receive the strut junctions. 
     
     
         11 . The apparatus according to  claim 10 , wherein the strut junctions define widened heads and the grooves are shaped to conform with the widened heads of the strut junctions. 
     
     
         12 . The apparatus according to  claim 6 , wherein the proximal and distal radial bearings are made of a ceramic material and the proximal and distal bearing housings are made of a second material that is moldable into a desired shape. 
     
     
         13 . The apparatus according to  claim 12 , wherein the proximal and distal bearing housings are made of a metal and/or an alloy. 
     
     
         14 . The apparatus according to  claim 13 , wherein the axial shaft comprises a metal and/or an alloy and wherein the axial shaft is covered with ceramic sleeves along regions of the axial shaft that come into contact with either of the proximal and distal bearings during operation of the left-ventricular assist device. 
     
     
         15 . A method of manufacturing a left ventricular assist device, the method comprising:
 forming a frame such that the frame is closed at its distal end and such that a plurality of strut junctions at a proximal end of the frame are maintained in open states;   coupling a pump-outlet tube to the frame, such that a distal portion of the pump-outlet tube extends to a distal end of the frame and defines one or more lateral blood-inlet openings that are configured to allow blood to flow from the subject's left ventricle into the pump-outlet tube, the pump-outlet tube being configured traverse an aortic valve of a subject, such that a proximal portion of the pump-outlet tube is disposed within the subject's aorta and the distal portion of the pump-outlet tube is disposed within the subject's left ventricle;   inserting an impeller into the frame via the proximal end of the frame, the impeller being configured to pump blood through the pump-outlet tube, by rotating; and   subsequently, closing the strut junctions at the proximal and of the frame, and maintaining the strut junctions in their closed states using a securing element.   
     
     
         16 . The method according to  claim 15 , wherein the securing element includes a ring, and maintaining the strut junctions in their closed states using the securing element comprises maintaining the strut junctions in their closed states using the ring. 
     
     
         17 . The method according to  claim 15 , wherein the pump-outlet tube further includes a coupling portion configured to extend distally from the frame, wherein the method further comprises coupling the coupling portion to a portion of the left-ventricular assist device that is distal to the frame. 
     
     
         18 . The method according to  claim 15 , wherein the left-ventricular assist device further includes:
 a proximal radial bearing disposed within a proximal bearing housing at a proximal end of the frame;   a distal radial bearing disposed within a distal bearing housing at a distal end of the frame;   an axial shaft upon which the impeller is disposed, the axial shaft passing through the proximal radial bearing and the distal radial bearing,   wherein maintaining the strut junctions in their closed states using the securing element comprises maintaining the strut junctions in their closed states by holding the struts junctions closed around an outer surface of the proximal bearing housing.   
     
     
         19 . The method according to  claim 18 , wherein the pump-outlet tube further includes a coupling portion configured to extend distally from the frame, wherein the method further comprises coupling the coupling portion to the distal bearing housing. 
     
     
         20 . The method according to  claim 18 , further comprising coupling a distal end of the frame to an outer surface of the distal bearing housing. 
     
     
         21 . The method according to  claim 18 , further comprising coupling a distal tip element to the distal bearing housing. 
     
     
         22 . The method according to  claim 18 , wherein the outer surface of the proximal bearing housing defines grooves that are shaped to receive the strut junctions, and wherein holding the struts junctions closed around the outer surface of the proximal bearing housing comprises holding the struts junctions within the grooves defined by the outer surface of the proximal bearing housing. 
     
     
         23 . The method according to  claim 22 , wherein the strut junctions define widened heads, and wherein holding the struts junctions within the grooves defined by the outer surface of the proximal bearing housing comprises holding the struts junctions within grooves that are shaped to conform with the widened heads of the strut junctions. 
     
     
         24 . The method according to  claim 18 , wherein the proximal and distal radial bearings are made of a ceramic material and the proximal and distal bearing housings are made of a second material that is moldable into a desired shape. 
     
     
         25 . The method according to  claim 24 , wherein the proximal and distal bearing housings are made of a metal and/or an alloy. 
     
     
         26 . The method according to  claim 25 , wherein the axial shaft comprises a metal and/or an alloy and wherein the method further comprises covering the axial shaft with ceramic sleeves along regions of the axial shaft that come into contact with either of the proximal and distal bearings during operation of the left-ventricular assist device. 
     
     
         27 - 107 . (canceled)