Magnetically shielded AIMD housing with window for magnetically actuated switch

• US 7,493,167 B2
• Filed: 11/01/2005
• Issued: 02/17/2009
• Est. Priority Date: 03/22/2005
• Status: Expired due to Fees

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch-Sierra, Inc.
• Inventors: Frysz, Christine A., Stevenson, Robert A., Hussein, Haytham
• Primary Examiner(s): Schaetzle; Kennedy J
• Assistant Examiner(s): SARCIONE, JESSICA LYNN
• Application Number:
  US11/163,848
• Publication Number:
  US 20060217792A1
• Time in Patent Office: 1,204 Days
• Field of Search: 607 30- 33, 607 36- 38, 607 59- 61, 128897-899, 128/903, 128/904, 128/908
• US Class Current: 607/36
• CPC Class Codes: A61N 1/16 Screening or neutralising undesirable influences from or using, atmospheric or terrestrial radiation or fields using atmospheric electricity or earth currents H05F3/00
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3752 Details of casing-lead connections

Abstract

An active implantable medical device (AIMD) having a magnetic shield on its housing for shielding the interior of the device from magnetic fields originating outside the housing. The magnetic shield is created using a magnetic absorbing coating on the inner surface of the housing. The AIMD includes an area of the housing left without the magnetic shield, a magnetic window, adjacent to a magnetically actuated device located inside of the housing. The magnetic window permits activation of the magnetically actuated device.

Claims

1. An active implantable medical device, comprising:

a housing having a terminal through which a lead wire extends;

a magnetically actuated device disposed within the housing; and

a magnetic shield disposed adjacent to the housing for shielding an interior of the housing from magnetic fields originating exteriorly of the housing, the magnetic shield including a window adjacent to the magnetically actuated device, and wherein the magnetic shield comprises a coating applied to interior surfaces of the housing.

2. The active implantable medical device of claim 1, wherein the coating comprises ferrous paint, nickel plating, nickel coating, nano-materials, Mu-metal materials, or a sogel or slurry of nano-materials containing magnetic dipoles.

3. The active implantable medical device of claim 1, wherein the magnetically actuated device is a reed switch, a Hall-effect device, an embedded telemetry coil, a low frequency telemetry coil, or a close-coupled subcutaneous battery recharging circuit.

4. The active implantable medical device of claim 1, including a sub-housing for the magnetically actuated device, the sub-housing overlaying the magnetic shield window so that the magnetically actuated device is disposed between the window and the sub-housing.

5. The active implantable medical device of claim 4, including a secondary magnetic shield disposed adjacent to the sub-housing.

6. The active implantable medical device of claim 5, wherein the secondary magnetic shield comprises a coating applied to interior surfaces of the sub-housing.

7. The active implantable medical device of claim 6, wherein the secondary magnetic shield coating comprises ferrous paint, nickel plating, nickel coating, nano-materials, Mu-metal materials, or a sogel or slurry of nano-materials containing magnetic dipoles.

8. The active implantable medical device of claim 4, wherein the sub-housing comprises an electrical shield.

9. The active implantable medical device of claim 1, wherein the terminal comprises an insulator through which the lead wire extends, and a terminal magnetic shield.

10. The active implantable medical device of claim 9, wherein the terminal magnetic shield comprises non-magnetic electrodes within the insulator.

11. The active implantable medical device of claim 10, wherein the non-magnetic electrodes comprise nickel electrodes.

12. The active implantable medical device of claim 1, wherein the housing comprises an electrical shield.

13. The active implantable medical device of claim 12, wherein the electrical shield comprises titanium.

14. The active implantable medical device of claim 1, wherein the AIMD comprises a cardiac pacemaker, an implantable defibrillator, a congestive heart failure device, a hearing implant, a cochlear implant, a neurostimulator, a drug pump, a ventricular assist device, an insulin pump, a spinal cord stimulator, an implantable sensing system, a deep brain stimulator, an artificial heart, an incontinence device, a vagus nerve stimulator, a bone growth stimulator, a gastric pacemaker, or a prosthetic device.

15. An active implantable medical device, comprising:

a housing having a terminal through which a lead wire extends, wherein the housing comprises an electrical shield;

a magnetically actuated device disposed within the housing;

a magnetic shield disposed adjacent to the housing for shielding an interior of the housing from magnetic fields originating exteriorly of the housing, the magnetic shield including a window adjacent to the magnetically actuated device;

a sub-housing for the magnetically actuated device, the sub-housing overlaying the magnetic shield window so that the magnetically actuated device is disposed between the window and the sub-housing; and

a secondary magnetic shield disposed adjacent to the sub-housing.

16. The active implantable medical device of claim 15, wherein the magnetic shield and the secondary magnetic shield comprise coatings applied to interior surfaces of the housing and the sub-housing.

17. The active implantable medical device of claim 16, wherein the coatings comprise ferrous paint, nickel plating, nickel coating, nano-materials, Mu-metal materials, or a sogel or slurry of nano-materials containing magnetic dipoles.

18. The active implantable medical device of claim 16, wherein the magnetically actuated device is a reed switch, a Hall-effect device, an embedded telemetry coil, a low frequency telemetry coil, or a close-coupled subcutaneous battery recharging circuit.

19. The active implantable medical device of claim 15, wherein the terminal comprises an insulator through which the lead wire extends, and a terminal magnetic shield.

20. The active implantable medical device of claim 19, wherein the terminal magnetic shield comprises non-magnetic electrodes within the insulator.

21. The active implantable medical device of claim 20, wherein the non-magnetic electrodes comprise nickel electrodes.

22. The active implantable medical device of claim 15, wherein the sub-housing comprises an electrical shield.

23. The active implantable medical device of claim 22, wherein the electrical shields comprise titanium.

24. The active implantable medical device of claim 15, wherein the AIMD comprises a cardiac pacemaker, an implantable defibrillator, a congestive heart failure device, a hearing implant, a cochlear implant, a neurostimulator, a drug pump, a ventricular assist device, an insulin pump, a spinal cord stimulator, an implantable sensing system, a deep brain stimulator, an artificial heart, an incontinence device, a vagus nerve stimulator, a bone growth stimulator, a gastric pacemaker, or a prosthetic device.

25. An active implantable medical device, comprising:

a housing having a terminal insulator through which a lead wire extends, and a terminal magnetic shield;

a magnetically actuated device disposed within the housing;

a magnetic shield disposed adjacent to the housing for shielding an interior of the housing from magnetic fields originating exteriorly of the housing, the magnetic shield including a window adjacent to the magnetically actuated device;

a sub-housing for the magnetically actuated device, the sub-housing overlaying the magnetic shield window so that the magnetically actuated device is disposed between the window and the sub-housing; and

a secondary magnetic shield disposed adjacent to the sub-housing.

26. The active implantable medical device of claim 25, wherein the AIMD comprises a cardiac pacemaker, an implantable defibrillator, a congestive heart failure device, a hearing implant, a cochlear implant, a neurostimulator, a drug pump, a ventricular assist device, an insulin pump, a spinal cord stimulator, an implantable sensing system, a deep brain stimulator, an artificial heart, an incontinence device, a vagus nerve stimulator, a bone growth stimulator, a gastric pacemaker, or a prosthetic device.

27. The active implantable medical device of claim 26, wherein the magnetic shield and the secondary magnetic shield comprise coatings applied to interior surfaces of the housing and the sub-housing.

28. The active implantable medical device of claim 27, wherein the coatings comprise ferrous paint, nickel plating, nickel coating, nano-materials, Mu-metal materials, or a sogel or slurry of nano-materials containing magnetic dipoles.

29. The active implantable medical device of claim 26, wherein the magnetically actuated device is a reed switch, a Hall-effect device, an embedded telemetry coil, a low frequency telemetry coil, or a close-coupled subcutaneous battery recharging circuit.

30. The active implantable medical device of claim 25, wherein the terminal magnetic shield comprises non-magnetic electrodes within the insulator.

31. The active implantable medical device of claim 30, wherein the non-magnetic electrodes comprise nickel electrodes.

32. The active implantable medical device of claim 31, wherein the electrical shield comprises titanium.

33. The active implantable medical device of claim 25, wherein the housing and the sub-housing both comprise an electrical shield.