Piezoelectric vascular implant release device

• US 20040186464A1
• Filed: 03/20/2003
• Published: 09/23/2004
• Est. Priority Date: 03/20/2003
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Mamayek, Don, Porter, Stephen Christopher
• Granted Patent: US 8,123,774 B2
• Time in Patent Office: Days
• US Class Current: 606/32
• CPC Class Codes: A61B 17/12022 Occluding by internal devices, e.g. balloons or releasable wires plugging an opening in the wall of an organ A61B17/0057; occluders for the cervical canal A61F6/146; vas deferens occluders A61F6/20
• CPC Class Codes: A61B 2017/0011 piezoelectric
• CPC Class Codes: A61B 2017/1209 detachable by electrical current or potential, e.g. electroactive polymer

Abstract

The present invention relates to a devices and methods for their use for the release of medical workpieces such as, without limitation, embolic devices, from apparatuses used to deliver them to a target site in a patient'"'"'s body involving use of a piezoelectric member that is fracturable and/or an adhesive layer that is susceptible to adhesive or cohesive failure.

Claims

1. A device for releasing a medical workpiece at a target site in a patient'"'"'s body, comprising:

a delivery apparatus comprising an elongate member having a proximal and a distal end;

a piezoelectric member having a proximal and a distal end, the proximal end being directly or operatively coupled to the elongate member at or near its distal end;

at least two electrical conducting members, each having a distal end electrically coupled to the piezoelectric member and a proximal end electrically coupled to a signal generator; and

,

a medical workpiece having a proximal and a distal end, the proximal end being directly or operatively coupled to the distal end of the piezoelectric member.

2. The device of claim 1, wherein the elongate member is a pusher wire.

3. The device of claim 1, wherein the elongate member is a microcatheter.

4. The device of claim 1, wherein the electrical conducting members comprise electrically conductive wires.

5. The device of claim 4, wherein the pusher wire comprises one of the electrical conducting members.

6. The device of claim 1, wherein the piezoelectric member is operatively coupled to the medical workpiece through an adhesive layer disposed between the piezoelectric member and the workpiece, the adhesive layer comprising a proximal face that forms a first interfacial bond with a distal face of the piezoelectric member and a distal face that forms a second interfacial bond with a proximal face of the workpiece.

7. The device of claim 6, wherein the adhesive layer is susceptible to adhesive and/or cohesive failure.

8. The device of claim 6, wherein adhesive failure comprises failure of the interfacial bond between the piezoelectric member and the adhesive layer, failure of the interfacial bond between the adhesive layer and the workpiece, or both.

9. The device of claim 7, wherein cohesive failure comprises fracturing of the adhesive layer.

10. The device of claim 9, wherein the adhesive layer comprises one or more engineered structural flaws.

11. The device of claim 10, wherein the engineered structural flaw(s) comprise(s):

one or more discontinuities in one or more faces of the adhesive layer;

one or more internal discontinuities in the adhesive layer;

or,

a combination of one or more face discontinuities and one or more internal discontinuities in the adhesive layer.

12. The device of claim 7, wherein the adhesive layer is selected from the group consisting of a glass, a ceramic, a metal and a polymer.

13. The device of claim 1, wherein the piezoelectric substance is fracturable.

14. The device of claim 13, wherein the fracturable piezoelectric substance comprises one or more engineered structural flaws.

15. The device of claim 14, wherein the engineered structural flaw(s) comprise(s):

one or more discontinuities in one or more faces of the piezoelectric substance;

one or more internal discontinuities in the structure of the piezoelectric member, wherein the discontinuities begin at one face of the piezoelectric member and terminate within the member, begin at one face and terminate at another face of the member, begin and terminate entirely within the internal structure of the member, or a combination of these;

or,

a combination or one or more discontinuities in one or more faces and one or more discontinuities in the internal structure of the piezoelectric member.

16. The device of claim 13, wherein the piezoelectric member comprises a piezoelectric substance selected from the group consisting of a piezoelectric crystal, a piezoelectric ceramic and a piezoelectric polymer.

17. The device of claim 1, wherein:

either the distal end of the piezoelectric member or the distal end of the elongate member comprises a first coupling structure; and

,

the proximal end of the medical workpiece comprises a second coupling structure that is at least partially complementary to the first coupling structure, wherein;

when the second coupling structure is in complementary alignment with the first coupling structure, the medical workpiece is releasably coupled, directly or operatively, to the delivery apparatus.

18. The device of claim 17, wherein:

either the first or the second coupling structure comprises a protrusion surface that has a selected shape; and

,

the other coupling structure comprises a cavity surface that is at least partially complementary to the protrusion surface.

19. The device of claim 18, wherein:

the protrusion surface comprises a cylinder, a cone or a truncated cone; and

,

the cavity surface defines a cylindrical, conical or truncated-conical void.

20. The device of claim 18, wherein:

the protrusion surface comprises a sphere having a diameter;

the cavity comprises at least one cross-sectional dimension of which is complementary to the diameter of the sphere.

21. The device of claim 17, further comprising:

a lumen described by an inside surface of the piezoelectric member, the lumen being disposed in the piezoelectric member such that an axis thereof aligns with the medical workpiece; and

,

a plunger member having a proximal and a distal end, the plunger being slidably disposed within the lumen, wherein;

at least one cross-sectional dimension of the plunger is complementary to at least one cross-sectional dimension of the lumen such that when no electrical signal is being sent to the piezoelectric member, the plunger is releasably coupled, directly or operatively, to the piezoelectric member.

22. The device of claim 17, further comprising:

a cavity surface defining a cavity in the distal portion of the elongate member; and

,

an actuator member that is either slidably disposed within the cavity or is coupled to the cavity surface, the actuator also being directly or operatively coupled to the piezoelectric member, wherein;

at least a portion of the distal end of the elongate member comprises the first coupling structure.

23. The device of claim 17, further comprising:

a cavity surface defining a cavity in the distal portion of the piezoelectric member, wherein,

at least a portion of the distal end of the piezoelectric member comprises the first coupling structure.

24. The device of any one of claim 1-23, wherein:

the target site is an aneurysm, an arteriovenous malformation, a fistula or a tumor; and

,

the medical workpiece is an embolic device.

38. The method of any one of claims 22-37, wherein:

the target site is an aneurysm, an arteriovenous malformation, a fistula or a tumor; and

,

the medical workpiece is an embolic device.

25. A method for delivering a medical workpiece to a target site in a patient, comprising:

providing a delivery apparatus comprising an elongate member having a proximal and a distal end;

providing a piezoelectric member having a proximal and a distal end, the proximal end of the piezoelectric member being directly or operatively coupled to the elongate member at or near its distal end;

providing at least two electrical conducting members, each having a distal end electrically coupled to the piezoelectric member and a proximal end electrically coupled to a signal generator;

providing a medical workpiece having a proximal and a distal end, the proximal end being directly or operatively coupled to the distal end of the piezoelectric member;

directing the distal end of elongate member to the target site;

positioning the workpiece at or in the target site;

generating an electrical signal; and

,

transmitting the electrical signal through the electrical conducting members to the piezoelectric member, thereby effecting release of the medical workpiece.

26. The method of claim 25, wherein providing a delivery apparatus comprises providing a microcatheter.

27. The method of claim 25, wherein providing a delivery apparatus comprises providing a pusher wire.

28. The method of claim 25, wherein the electrical conducting members comprise electrically conducting wires.

29. The method of claim 25, wherein:

operatively coupling the piezoelectric member to the medical workpiece comprises providing an adhesive layer disposed between piezoelectric member and the workpiece, the adhesive layer comprising a proximal face that forms a first interfacial bond with a distal face of the piezoelectric member and a distal face that forms a second interfacial bond with a proximal face of the workpiece.

30. The method of claim 29, further comprising providing the adhesive layer with an engineered structural flaw that renders it susceptible to fracture.

31. The method of claim 30, wherein providing the adhesive layer with an engineered structural flaw comprises:

creating one or more discontinuities in one or more faces of the adhesive layer;

creating one or more internal discontinuities in the adhesive layer;

or,

creating a combination of one or more facial discontinuities and one or more internal discontinuities in the adhesive layer.

32. The method of claim 25, further comprising providing the piezoelectric member with one more engineered structural flaws.

33. The method of claim 32, wherein providing the piezoelectric member with one or more engineered flaws comprise(s):

creating one or more discontinuities in one or more faces of the piezoelectric member;

creating one or more internal discontinuities in the structure of the piezoelectric, wherein the discontinuities begin at one face of the member and terminate within the member, begin at one face, pass through the member and terminate at another face, begin and terminate entirely in the internal structure of the member, or a combination of these;

or,

a combination of one or more discontinuities in one or more faces, and one or more discontinuities in the internal structure, of the piezoelectric member.

34. The method of claim 25, further comprising:

providing the distal end of the piezoelectric member with a first coupling structure;

providing the proximal end of the workpiece with a second coupling structure that is at least partially complementary to the first coupling structure such that, when no electrical signal is being generated, the piezoelectric member is releasably coupled, directly or operatively, to the workpiece.

35. The method of claim 25, further comprising:

providing the piezoelectric member with an inside surface that defines a lumen, an axis of which aligns with the medical workpiece;

providing a plunger member that is slidably disposed in the lumen, wherein,

at least one cross-sectional dimension of the plunger is complementary to at least one cross-sectional dimension of the lumen such that, when no electrical signal is being sent to the piezoelectric member, the plunger is releasably coupled, directly or operatively, to the piezoelectric member.

36. The method of claim 25, further comprising:

providing the piezoelectric member with a cavity surface that defines a cavity, wherein;

at least a portion of the cavity surface is complementary to at least a portion of a surface of the medical workpiece such that, when the two portions are in complementary alignment, the medical workpiece is releasably coupled to the piezoelectric member; and

,

essentially completely filling the cavity with a non-compressible liquid.

37. The method of claim 25, further comprising:

providing the distal portion the elongate member with a cavity surface that defines a cavity and that is at least partially complementary to a surface of the medical workpiece such that, when the cavity surface and the medical workpiece surface are in complementary alignment, the medical workpiece is releasably coupled to the elongate member;

providing an actuator member that is either slidably disposed in or coupled to the cavity surface and that is also directly or operatively coupled to the piezoelectric member; and

,

essentially filling the cavity with a non-compressible fluid.