Heart assist device with expandable impeller pump

Patent metadata

Field	Value
Publication number	US-9364592-B2
Application number	US-94559410-A
Country	US
Kind code	B2
Filing date	Nov 12, 2010
Priority date	Sep 17, 2004
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

An impeller includes a hub and at least one blade supported by the hub. The impeller has a stored configuration in which the blade is compressed so that its distal end moves towards the hub, and a deployed configuration in which the blade extends away from the hub. The impeller may be part of a pump for pumping fluids, such as pumping blood within a patient. A blood pump may include a cannula having a proximal portion with a fixed diameter, and a distal portion with an expandable diameter. The impeller may reside in the expandable portion of the cannula. The cannula may have a compressed diameter which allows it to be inserted percutaneously into a patient. Once at a desired location, the expandable portion of the cannula may be expanded and the impeller expanded to the deployed configuration. A flexible drive shaft may extend through the cannula for rotationally driving the impeller within the patient's body.

First claim

The invention claimed is:

1. A method of manipulating an impeller of a pump, the pump comprising a cannula disposed about an impeller, the cannula comprising a mesh having a first plurality of circumferential rings and an enclosure disposed about the mesh, each circumferential ring of the first plurality of circumferential rings comprising a plurality of distal crests, a plurality of proximal troughs, and a plurality of side segments extending between respective crests and troughs, wherein a first connector connects a first side segment of a first circumferential ring to a second circumferential ring, wherein each circumferential ring of the first plurality of circumferential rings is connected to an adjacent circumferential ring of the first plurality of circumferential rings by at least one connector, the cannula having an inlet and an outlet spaced from the inlet along an axial direction of the pump, the enclosure defining a space for the flow of blood in the axial direction, the method comprising:
compressing the impeller to a compressed configuration, said compressing storing potential energy in the impeller; and
retaining the impeller in the compressed configuration within a portion of the cannula.

2. The method of claim 1 , further comprising causing an expandable portion of the cannula to be held in a compressed configuration by a retainer sheath.

3. The method of claim 2 , wherein a radially outward portion of the impeller is folded towards a hub of the impeller in the compressed configuration to cause the blade(s) to be in a reduced diameter as compared to a deployed diameter.

4. The method of claim 2 , further comprising providing relative motion between the retainer sheath and the cannula to cause the cannula to be compressed to the compressed configuration.

5. The method of claim 4 , comprising moving the retainer sheath over at least a portion of the cannula to hold the cannula in the compressed configuration and to hold the impeller in the compressed configuration.

6. The method of claim 4 , further comprising deploying the impeller by applying opposite relative motion between the retainer sheath and the cannula.

7. The method of claim 6 , further comprising deploying the impeller by releasing potential energy stored in the impeller.

8. The method of claim 6 , further comprising pumping blood through the cannula along the axial direction.

9. The method of claim 4 , further comprising applying a force to a proximal end of a drive shaft to cause relative motion, a distal end of the drive shaft being-coupled with the impeller.

10. The method of claim 1 , wherein the cannula comprises a reversibly expandable portion.

11. The method of claim 1 , wherein the cannula in the compressed configuration has a diameter that is less than or equal to one-half the diameter of the cannula in an expanded configuration.

12. The method of claim 1 , further comprising compressing the impeller to a reduced diameter of less than or equal to one-half of a deployed diameter.

13. The method of claim 1 , comprising deploying the impeller to a deployed diameter between about 6 mm and about 7 mm.

14. The method of claim 1 , further comprising compressing the impeller to a reduced diameter of between about 3 mm and about 4 mm.

15. The method of claim 1 , wherein a distal-most circumferential ring is distal of the impeller, and wherein a proximal-most circumferential ring is disposed near a proximal end of the impeller.

16. The method of claim 1 , wherein the enclosure is non-porous.

17. The method of claim 1 , wherein the mesh includes a coating, the enclosure defined at least in part by the mesh and the coating.

18. The method of claim 17 , wherein a distal end of the coating is proximal a distal end of the mesh.

19. The method of claim 17 , wherein the coating comprises an elastic coating over an outside surface of the circumferential rings.

20. A method of manipulating an expandable pump, the pump comprising an expandable impeller and a cannula having an expandable portion comprising a mesh extending between a proximal portion of the cannula and a distal portion of the cannula and at least about the impeller, the cannula comprising an enclosure disposed about the mesh, the mesh comprising a first plurality of circumferential rings, each circumferential ring of the first plurality of circumferential rings comprising a plurality of distal crests, a plurality of proximal troughs, and a plurality of side segments extending between respective crests and troughs, wherein a first connector connects a first side segment of a first circumferential ring to a second circumferential ring, wherein each circumferential ring of the first plurality of circumferential rings is connected to an adjacent circumferential ring of the first plurality of circumferential rings by at least one connector, the pump further comprising a retainer sleeve disposed over the cannula, the cannula having an inlet and an outlet spaced from the inlet along an axial direction of the pump, the enclosure defining a space for the flow of blood in the axial direction, the method comprising:
moving the retainer sleeve over the expandable portion of the cannula to compress the expandable portion of the cannula into a compressed state;
such that the compressing of the expandable portion of the cannula causes the impeller to be compressed within the cannula to be in a stored configuration,
the stored configuration being reversible to a deployed configuration by opposite relative motion.

21. The method of claim 20 , wherein the impeller is compressed by folding a radially outward portion of the impeller towards a hub of the impeller.

22. The method of claim 20 , wherein the mesh surrounds a plurality of interstitial voids, and wherein the expandable portion of the cannula has a stiffness that varies along a length of the expandable portion.

23. The method of claim 20 , wherein two of the circumferential rings of the first plurality of circumferential rings are connected by a plurality of axial connectors.

24. The method of claim 20 , wherein two of the circumferential rings of the first plurality of circumferential rings are at least partially interleaved.

25. The method of claim 24 , wherein the number of axial connectors per pair of circumferential rings decreases within the expandable portion of the cannula from a first level at a first zone adjacent to the proximal portion to a second lower level at a second zone between the first zone and the distal portion.

26. The method of claim 20 , further comprising expanding the expandable portion of the cannula, said expansion driven by potential energy stored in the expandable portion of the cannula.

27. The method of claim 20 , wherein the circumferential rings are at least partially interleaved.

28. The method of claim 20 , wherein a distal-most circumferential ring is distal of the impeller, and wherein a proximal-most circumferential ring is disposed near a proximal end of the impeller.

29. The method of claim 20 , wherein the cannula has a bending stiffness that varies along a length of the cannula.

30. The method of claim 20 , wherein the enclosure is non-porous.

31. The method of claim 20 , wherein the mesh includes a coating, the enclosure defined at least in part by the mesh and the coating.

Assignees

• Mcbride Mark W
• Boger David A
• Campbell Robert L
• Dillon Gregory P
• Hambric Stephen A
• Kunz Robert F
• Leschinsky Boris
• Mallison Thomas M
• Runt James P
• Walsh Justin M
• Penn State Res Found
• Thoratec Corp

Inventors

• Mcbride Mark W
• Boger David A
• Campbell Robert L
• Dillon Gregory P
• Hambric Stephen A
• Kunz Robert F
• Leschinsky Boris
• Mallison Thomas M
• Runt James P
• Walsh Justin M

Classifications

• F04D29/542

  Bladed diffusers (fixing blades to stators F01D9/042) · CPC title

• A61M2205/0266

  Shape memory materials · CPC title

• F04D29/181

  Axial flow rotors (F04D29/185 take precedence) · CPC title

• F04D29/528

  especially adapted for liquid pumps · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title