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EP-4252827-B1 - VENTRICULAR ASSIST DEVICE

EP4252827B1EP 4252827 B1EP4252827 B1EP 4252827B1EP-4252827-B1

Inventors

  • TUVAL, YOSI
  • LUBINSKI, Gad
  • TROSHIN, VICTOR
  • ZEMER HAREL, Hagit
  • FRIEDLAND, Ori
  • ROSENBLUM, Daniel
  • ROZENFELD, Avi

Dates

Publication Date
20260506
Application Date
20220830

Claims (13)

  1. An apparatus comprising: a ventricular assist device (20) comprising: an axial shaft (92); an impeller (50) disposed on the axial shaft (92), the impeller (50) being configured to pump blood; a frame (34) disposed around the impeller; a distal thrust bearing (260) disposed within the frame (34), the distal end of the axial shaft (92) being configured to engage with the distal thrust bearing (260) such as to prevent the axial shaft (92) from undergoing axial motion in response to variations in the pressure gradient against which the impeller (50) pumps blood; and a plurality of connecting struts (264) extending radially inwardly from the frame (34) to the distal thrust bearing (260) and coupling the thrust bearing (260) to the frame (34), the frame (34) and the connecting struts (264) being formed as a single integral body, wherein the ventricular assist device (20) further comprises a pump-outlet tube (24) configured to traverse an aortic valve of the subject, such that a proximal portion of the pump-outlet tube (24) is disposed within an aorta of the subject and a distal portion of the pump-outlet tube (24) is disposed within the subject's left ventricle, the distal portion of the pump-outlet tube (24) extending to the distal end of the frame (34) and defining 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), and wherein the distal portion of the pump-outlet tube (24) defines more than 10 blood-inlet openings (108) that are sized such as (a) to allow blood to flow from the subject's left ventricle into the pump-outlet tube (24) and (b) to block structures from the subject's left ventricle from entering into the frame (34).
  2. The apparatus according to claim 1, wherein the frame, the connecting struts (264), and the thrust bearing (260) are all formed as a single integral body.
  3. The apparatus according to claim 1 or claim 2, wherein the ventricular assist device further comprises an impeller-stabilizing spring (68) disposed around the axial shaft (92) between a distal end of the impeller (50) and the thrust bearing (260), the impeller-stabilizing spring (68) being configured to stabilize the distal end of the impeller (50).
  4. The apparatus according to claim 3, wherein the impeller (50) is configured to be radially constrained by becoming axially elongated and wherein the impeller-stabilizing spring (68) is configured to become compressed such as to accommodate the axial elongation of the impeller (50).
  5. The apparatus according to claim 3, wherein the impeller-stabilizing spring (68) is coupled to a distal end of the impeller (50).
  6. The apparatus according to claim 3, wherein the ventricular assist device (20) further comprises a proximal bearing (116) and a proximal impeller-stabilizing spring (68) disposed around the axial shaft (92) between a proximal end of the impeller (50) and the proximal bearing (116).
  7. The apparatus according to claim 3, wherein the impeller-stabilizing spring (68) is coupled to the thrust bearing (260).
  8. The apparatus according to claim 3, further comprising an elastomeric material (69) that is coupled to the impeller-stabilizing spring (68), such that at least a portion of the axial shaft (92) between a distal end of the impeller (50) and the thrust bearing (260) is covered by a combination of the impeller-stabilizing spring (68) and the elastomeric material (69).
  9. The apparatus according to claim 8, wherein the ventricular assist device (20) comprises a purging system that is configured to pump a purging fluid through a lumen defined by the axial shaft (92), such that at least a portion of the purging fluid flows proximally through an interface between the axial shaft (92) and the combination of the impeller-stabilizing spring (68) and the elastomeric material (69).
  10. The apparatus according to claim 8, wherein the elastomeric material (69) is coupled to the impeller-stabilizing spring (68) in such a manner that the elastomeric material (69) changes shape to conform to shape changes that the impeller-stabilizing spring (68) undergoes.
  11. The apparatus according to claim 10, wherein the elastomeric material (69) is configured to undergo the changes in shape without the elastomeric material (69) becoming broken or collapsing.
  12. The apparatus according to claim 10, wherein the elastomeric material (69) is configured not to become creased as a result of the impeller-stabilizing spring (68) being compressed.
  13. The apparatus according to claim 1, wherein the distal portion of the pump-outlet tube (24) defines more than 50 blood-inlet openings (108) that are sized such as (a) to allow blood to flow from the subject's left ventricle into the pump-outlet tube (24) and (b) to block structures from the subject's left ventricle from entering into the frame (34).

Description

CROSS-REFERENCES TO RELATED APPLICATIONS The present application claims priority from: US Provisional Patent Application 63/254,321 to Tuval, entitled "Ventricular assist device," filed October 11, 2021; andUS Provisional Patent Application 63/317,199 to Tuval, entitled "Ventricular assist device," filed March 07, 2022. FIELD OF EMBODIMENTS OF THE INVENTION The present invention relates to apparatus comprising a ventricular assist device. BACKGROUND Ventricular assist devices are mechanical circulatory support devices designed to assist and unload cardiac chambers in order to maintain or augment cardiac output. They are used in patients suffering from a failing heart and in patients at risk for deterioration of cardiac function during percutaneous coronary interventions. Most commonly, a left-ventricular assist device is applied to a defective heart in order to assist left-ventricular functioning. In some cases, a right-ventricular assist device is used in order to assist right-ventricular functioning. Such ventricular assist devices are either designed to be permanently implanted or mounted on a catheter for temporary placement. GB2504175 relates to a distal bearing support for an impeller assembly that is used in a catheter pump. The distal bearing support comprises expandable supports disposed on an impeller shaft, distal of the impeller. The expandable supports have lobes or digits having an arcuate outer surface and which are biased to expand radially against a cannula housing wall to improve bending stiffness and maintain an impeller blade tip working clearance gap adjacent the wall. US9533084 relates to an intravascular blood pump comprising a shaft and an impeller fastened to the shaft. The impeller and a distal portion of the shaft are enclosed by a housing made of a sack-like polyurethane skin and thus forming an envelope around the impeller. The distal end of the envelope comprises a hub in which a distal end of the shaft is supported. The shaft cannot be axially displaced but is adapted to rotate in the hub such that the envelope is secured against rotation with the rotating shaft. EP3545983 relates to a blood pump having a housing and a rotor arranged in the housing. The rotor has a spindle-shaped design. Furthermore, the housing follows at least in parts the spindle-shaped widening of the rotor. US8690749 relates to a wireless compressible heart pump, and discloses apparatus with a compressible construction having a wireless power source structured around a cylindrical-shaped support that suspends a motor within the vascular system while also supporting an impeller pump that can be made to be collapsible. SUMMARY OF EMBODIMENTS In accordance with the present invention, there is provided apparatus as defined in appended independent claim 1. Embodiments of the present invention are defined in the appended claims dependent on independent claim 1. In accordance with some applications of the present disclosure, a ventricular assist device includes a motion-cushioning spring. As described in further detail hereinbelow, typically, during operation of the ventricular assist device, i.e., as an impeller of the ventricular assist device is rotating, the impeller of the ventricular assist device undergoes axial back-and-forth motion. For some applications, as the impeller undergoes the axial back-and-forth motion, the motion-cushioning spring is configured to act as a shock absorber, to provide cushioning to the motion. As the impeller moves distally from a systolic position to a diastolic position, the motion-cushioning spring becomes more compressed. For some applications, the impeller is configured to be radially constrained (i.e., crimped) by becoming axially elongated, and the motion-cushioning spring is configured to become compressed such as to accommodate the axial elongation of the impeller. For some applications, the motion-cushioning spring is coupled to an elastomeric material (such as polyurethane, and/or silicone), such that at least a portion of an axial shaft of the ventricular assist device that is between a distal end of the impeller and a distal radial bearing is covered by the elastomeric material. For some applications, coupling the elastomeric material to the spring reduces a risk of the generation of thrombi and/or hemolysis by the spring, relative to if the spring is not coupled to the elastomeric material. It is noted that the scope of the present disclosure includes providing the motion-cushioning spring in the absence of elastomeric material, as may be desirable in some cases. For some applications, the spring is coated with the elastomeric material with the elastomeric material extending between adjacent windings of the spring. Alternatively, the spring is embedded within the elastomeric material. Typically, the elastomeric material is coupled to the motion-cushioning spring in such a manner that the elastomeric material changes shape (e.g., by stretching and compressing) to c