Thermal Management of Implantable Medical Devices

• US 20090082832A1
• Filed: 09/25/2008
• Published: 03/26/2009
• Est. Priority Date: 09/25/2007
• Status: Abandoned Application

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Carbunaru, Rafael, Jaax, Kristen N., Schleicher, Brett, Digiore, Andrew
• Application Number:
  US12/237,631
• Publication Number:
  US 20090082832A1
• Time in Patent Office: Days
• US Class Current: 607/59
• CPC Class Codes: A61N 1/37 Monitoring; Protecting
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Systems and techniques for thermal management of implantable medical devices. In one aspect, an implantable device adapted for implantation in a body includes a conductor component that conducts an electrical current in response to the body in which that implantable device is implanted being subjected to an alternating electromagnetic field and a thermal management component in thermal contact with the conductor component and configured to manage excess heat generated by the conduction of the electrical current. The thermal management component comprises a material that undergoes a phase transition at a temperature above the temperature of the body in which the implantable device is adapted to be implanted.

Claims

1. An implantable device adapted for implantation in a body, comprising:

a conductor component that conducts an electrical current in response to the body in which that implantable device is implanted being subjected to an alternating electromagnetic field; and

a thermal management component in thermal contact with the conductor component and configured to manage excess heat generated by the conduction of the electrical current;

wherein the thermal management component comprises a material that undergoes a phase transition at a temperature between zero and ten degrees Celsius above the temperature of the body in which the implantable device is adapted to be implanted.

2. The implantable device of claim 1, wherein the conductor component comprises an electrically conductive loop.

3. The implantable device of claim 2, wherein the electrically conductive loop comprises a conducting coil of a charging component that is configured to convert electrical or magnetic energy from outside the body in which the implantable device is adapted to be implanted.

4. The implantable device of claim 1, wherein:

the implantable device comprises a pacemaker; and

the conductor component comprises a wire in a lead of the pacemaker.

5. The implantable device of claim 1, wherein:

the implantable device comprises a neurostimulator; and

the conductor component comprises a wire in a lead of the neurostimulator.

6. The implantable device of claim 1, wherein the implantable device comprises an orthopedic implant.

7. The implantable device of claim 1, wherein the conductor component comprises a conductive linear wire in a lead.

8. The implantable device of claim 1, wherein the conductive linear wire has a length of about 26 cm or about 13 cm.

9. The implantable device of claim 1, wherein the implantable device further comprises:

an active component configured to perform one or more medical activities; and

a charging component that comprises the conductor component and is configured to convert energy from outside a body in which the implantable device is implanted into energy that can consumed by the active component,

wherein

the conversion of energy includes the conduction of the electrical current by the conductor component, and

the thermal management component is in thermal contact with the conductor component of the charging component and is configured to manage excess heat generated in the conversion of energy from outside the body.

10. The implantable device of claim 9, wherein the thermal management component is interposed between the active component and the charging component.

11. The implantable device of claim 9, wherein the thermal management component surrounds the charging component.

12. The implantable device of claim 9, wherein the active component comprises electrical circuitry of an implantable pulse generator.

13. The implantable device of claim 9, wherein the charging component comprises a conducting coil.

14. The implantable device of claim 9, further comprising a thermal barrier between the active component and the charging component.

15. The implantable device of claim 1, further comprising a container configured to restrict flow of the material of the thermal management component.

16. The implantable device of claim 15, wherein the container comprises an elastic balloon.

17. The implantable device of claim 1, wherein the material undergoes the phase transition at a temperature between two and four degrees Celsius above the temperature of the body in which the implantable device is adapted for implantation.

18. The implantable device of claim 1, further comprising:

a system of one or more biocompatible housings, wherein at least one of the housings in the system comprises;

a magnetically non-transparent biocompatible material that encloses a power storage device of an implantable pulse generator; and

a magnetically transparent biocompatible material that encloses the conductor component and the thermal management component, wherein the conductor component comprises a charging coil configured to convert electrical or magnetic energy from outside a body in which the implantable device is implanted into energy that can be stored at the power storage device and the thermal management component is in thermal contact with the charging coil.

19. The implantable device of claim 18, wherein the system comprises:

a first biocompatible housing that comprises the magnetically transparent material; and

a second biocompatible housing that comprises the magnetically non-transparent material.

20. The implantable device of claim 19, wherein the system further comprises an insulated conductor that joins the first biocompatible housing and the second biocompatible housing.

21. The implantable device of claim 18, wherein the system comprises a single biocompatible housing comprising a magnetically transparent portion that comprises the magnetically transparent material and a magnetically non-transparent portion that comprises the magnetically non-transparent material.

22. The implantable device of claim 21, wherein:

the magnetically transparent portion comprises a ceramic;

the magnetically non-transparent portion comprises a metal.

23. The implantable device of claim 22, wherein:

the ceramic comprises zirconia; and

the metal comprises titanium.

24. The implantable device of claim 21, further comprising a brazed seam joining the magnetically transparent portion to the magnetically non-transparent portion.

25. The implantable device of claim 1, wherein the material that undergoes the phase transition comprises one or more of a clay, a paraffin, and an organic acid.

26. The implantable device of claim 1, wherein the material that undergoes the phase transition comprises one or more of a salt hydrate, a clathrate, and a eutectic organic or inorganic compound.

27. The implantable device of claim 1, wherein the material that undergoes the phase transition comprises one or more of paraffin 6106, potassium fluoride dehydrate, (KF 2H₂O), and lauric acid.

28. The implantable device of claim 1, wherein the material that undergoes the phase transition does not conduct electricity.

29. The implantable device of claim 1, wherein the material undergoes the phase transition at a temperature between two and four degrees Celsius above the temperature of the body in which the implantable device is to be implanted.

30. An implantable device comprising:

a first hermetically-sealed housing that houses an active component configured to perform medical activities;

a second hermetically-sealed housing that houses

a charging component configured to convert energy from outside a body in which the implantable device is implanted into energy that can be consumed by the active component, and

a material that undergoes a phase transition at a temperature between zero and twenty degrees Celsius above the temperature of the body in which the implantable device is to be implanted; and

an insulated conductor configured to conduct energy from the second hermetically-sealed housing to the active component housed in the first hermetically-sealed housing.

31. An implantable device comprising:

an active component configured to perform one or more medical activities;

a charging component configured to convert energy from outside a body in which the implantable device is implanted into potential energy; and

a thermal management component in thermal contact with the charging component and configured to manage excess heat generated by the charging component in converting energy from outside the body into potential energy,

wherein the thermal management component comprises a material that undergoes a phase transition at a temperature between zero and ten degrees above the temperature of the body in which the implantable device is to be implanted.

32. The implantable device of claim 31, wherein the charging component comprises an optical component responsive to light or other electromagnetic radiation generated outside the body.

33. The implantable device of claim 31, wherein the charging component comprises a mechanical component responsive to mechanical impulses generated outside the body.