Selectively activated shape memory device

• US 6,323,459 B1
• Filed: 04/18/2000
• Issued: 11/27/2001
• Est. Priority Date: 09/05/1996
• Status: Expired due to Term

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Maynard, Ronald S.
• Primary Examiner(s): Walberg, Teresa
• Assistant Examiner(s): Fuqua, Shawntina T
• Application Number:
  US09/551,828
• Time in Patent Office: 588 Days
• Field of Search: 219/209, 219/201, 219/522, 219/528, 219/533, 219/534, 219/548, 219/552, 219/553, 219/200, 219/549, 219/508, 604/53, 604/95, 604/93, 604/114, 604/281, 128/657, 128/658, 128/786, 337/140
• US Class Current: 219/209
• CPC Class Codes: A61B 1/0058 using shape-memory elements
• CPC Class Codes: A61F 2/848 having means for fixation to the vessel wall, e.g. barbs
• CPC Class Codes: A61F 2/92 Stents in the form of a rolled-up sheet expanding after insertion into the vessel , e.g. with a spiral shape in cross-section
• CPC Class Codes: A61M 25/0158 with magnetic or electrical means, e.g. by using piezo materials, electroactive polymers, magnetic materials or by heating of shape memory materials
• CPC Class Codes: F03G 7/065 using a shape memory element

Abstract

A shape memory device includes a shape memory alloy member configured to have at least a portion of the shape memory alloy member be selectively activated. A heating device is coupled to the member and configured to provide heat to a selected section of the member and activate at least a portion of the selected section.

Claims

1. A shape memory device, comprising:

a tubular actuator formed from a shape memory alloy mesh and configured so that at least a portion of the actuator may be selectively activated; and

a heating device coupled to the actuator and configured to provide heat to a selected section of the actuator to activate at least a portion of the selected section.

2. The device of claim 1, wherein the actuator is formed in a basket.

3. The device of claim 2, wherein the basket is thermally trained in a crushed configuration.

4. The device of claim 1, wherein the shape memory alloy mesh is co-extruded with an elastomer.

5. The device of claim 4, wherein the elastomer is formed according to a process selected from the group consisting of casting, heat shrinking, and dipping.

6. The device of claim 1, and further comprising a catheter positioned around the actuator.

7. The device of claim 6, wherein the actuator is positioned substantially parallel to a longitudinal axis of the catheter.

8. The device of claim 1, wherein the heating device includes a plurality of thin film heaters distributed at least partially circumferentially on the surface of the actuator.

9. The device of claim 8, and further including a control unit to selectively activate one or more of the thin film heaters to achieve a desired deflection.

10. The device of claim 1, and further comprising a slipping member coupled to at least a portion of the actuator, wherein the slipping member is configured to provide at least a portion of an exterior of the actuator with a low coefficient of friction.

11. The device of claim 1, and further comprising a sensor selected from the group consisting of a pressure sensor, a temperature sensor, an electrosonic sensor, a voltage potential sensor, a chemical sensor, a chemical potential sensor, and an electronic magnetic sensor.

12. The device of claim 1, wherein the device is configured to have a two-way shape memory affect.

13. A shape memory device, comprising:

an actuator formed from a perforated shape memory alloy constructed in a tubular configuration, and which is capable of being selectively activated; and

a heating device to provide heat to a selected section of the actuator to activate at least a portion of the selected section.

14. The device of claim 13, wherein the actuator is formed into a basket that is thermally-trained in a crushed configuration.

15. The device of claim 13, wherein the actuator is co-extruded with an elastomer.

16. The device of claim 13, and further comprising a catheter positioned around the actuator.

17. The device of claim 13, wherein the heating device includes a plurality of thin film heaters distributed at least partially circumferentially on the surface of the actuator.

18. The device of claim 13, and further including a control unit to selectively activate one or more of the thin film heaters to achieve a desired deflection of at least a portion of the actuator.

19. The device of claim 13, and further comprising a slipping member coupled to at least a portion of the actuator, wherein the slipping member is configured to provide at least a portion of an exterior of the actuator with a low coefficient of friction.

20. The device of claim 13, and futher comprising a sensor selected from the group consisting of a pressure sensor, a temperture sensor, and electrosonic sensor, a voltage potential sensor, a chemical sensor, a chemical potential sensor, and an electronic magnetic sensor.

21. The device of claim 13, wherein the actuator is configured to have a two-way shape memory affect.

22. An elongated tubular device including a device body extending between a device body distal end and a device body proximal end, the device body further comprising:

a shape memory alloy mesh formed into a tube and extending between the device body proximal and distal ends;

a plurality of independently controllable heating elements distributed over the device body, each of the independently controllable heating elements providing heat to an adjoining selected section of the shape memory alloy mesh and providing activation of only the selected section of the shape memory alloy mesh; and

means for energizing selected ones of the plurality of independently controllable heating elements to emit heat and induce a change in shape of the device body through activation of the adjoining selected section of the shape memory alloy mesh.

23. The device of claim 22, wherein an activation of at least a portion of the selected section provides a variable Young'"'"'s modulus of at least a portion of the shape memory alloy member.

24. The device of claim 22, wherein the activating means further comprises a micro-fabricated conductive path coupled to the plurality of independently controllable heating elements.

25. The device of claim 22, wherein the shape memory ally mesh is formed of a shape memory alloy sheet that is perforated and formed into a tube.

26. The device of claim 22, wherein the shape memory alloy mesh is a wire-like structure that is formed into a tube.

27. The device of claim 22, wherein the elongated tubular device has a longitudinal axis, and the plurality of independently controllable heating elements provide heat to an adjoining selected section of the shape memory alloy mesh to enable deflection of the device laterally relative to the longitudinal axis of the elongated tubular device.

28. An elongated tubular device including a device body extending between a device body distal end and a device body proximal end, the device body further comprising:

a shape memory alloy mesh formed into a tube and extending between the device body proximal and distal ends;

an insulating film positioned on a surface of the shape memory alloy mesh and electrically isolating the shape memory alloy mesh from passage of current through the shape memory alloy mesh; and

a plurality of independently controllable heating elements distributed over the insulating film, each of the independently controllable heating elements providing heat to an adjacent selected section of the shape memory alloy mesh through the insulating film and providing activation of only the selected section of the shape memory alloy mesh.

29. The device of claim 28, further comprising means for activating selected ones of the plurality of independently controllable heating elements to induce a change in shape of the device body.

30. The device of claim 29, wherein the elongated tubular device has a longitudinal axis, and the plurality of independently controllable heating elements provide heat to an adjoining selected section of the shape memory alloy mesh to enable deflection of the device laterally relative to the longitudinal axis of the elongated tubular device.

31. The device of claim 28, wherein the elongated tubular device has a longitudinal axis, and the plurality of independently controllable heating elements provide heat to an adjoining selected section of the shape memory alloy mesh to enable deflection of the device laterally relative to the longitudinal axis of the elongated tubular device.

32. The device of claim 28, wherein an activation of at least a portion of the selected section provides a variable Young'"'"'s modulus of at least a portion of the shape memory alloy member.

33. The device of claim 28, further comprising:

a micro-fabricated conductive path coupled to the plurality of independently controllable heating elements.

34. The device of claim 28, wherein the shape memory ally mesh is formed of a shape memory alloy sheet that is perforated and formed into a tube.

35. The device of claim 28, wherein the shape memory alloy mesh is a wire-like structure that is formed into a tube.