External Charger with Customizable Magnetic Charging Field

• US 20170281956A1
• Filed: 06/06/2017
• Published: 10/05/2017
• Est. Priority Date: 05/07/2010
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Carbunaru, Rafael, DiGiore, Andrew, Whitehurst, Todd
• Granted Patent: US 10,350,420 B2
• Time in Patent Office: Days
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Improved external chargers for charging an implantable medical device, and particularly useful in charging a plurality of such devices, are disclosed. Each of the various embodiments include a plurality of field customization coils for customizing the magnetic charging field generated by the external charger such that the magnetic charging field is not radially symmetric. For example, one embodiment includes a primary coil with a plurality of field customization coils distributed radially with respect to the coil. The generated magnetic charging field can be rendered radially asymmetric by selectively activating or disabling the field customization coils in response to data quantifying the coupling between the various implants and the field customization coils in the charger. If there is a relatively high coupling between a particular implant and a particular customization coil for example, that customization coil can be activated to counter the magnetic charging field at that location, while still maintaining a relatively high magnetic charging field at the location of other implants that may have lower couplings.

Claims

1. A method for charging at least one implantable medical device using an external charger comprising a plurality of coils, the method comprising:

differently activating the plurality of coils in the external charger to generate a magnetic charging field that is radially asymmetric, wherein the plurality of coils are differently activated in accordance with at least one coupling parameter that is indicative of coupling between the external charger and the at least one implantable medical device.

2. The method of claim 1, wherein each coupling parameter is indicative of the coupling between one of the coils and one implantable medical device.

3. The method of claim 1, wherein the plurality of coils comprises one primary coil and one or more customization coils.

4. The method of claim 3, wherein the plurality of coils are positioned radially symmetrically about a main axis of the primary coil.

5. The method of claim 3, wherein the coils are differently activated by some, but not all, of the coils being coupled in series with the primary coil.

6. The method of claim 3, wherein increasing a current that is supplied to at least one of the customization coils decreases a strength of the magnetic charging field near the at least one customization coil.

7. The method of claim 3, wherein increasing a current that is supplied to at least one of the customization coils increases a strength of the magnetic charging field near the at least one customization coil.

8. The method of claim 1, wherein the coils are differently activated by carrying different customization currents.

9. The method of claim 1, wherein the coils are differently activated by some, but not all, of the coils being closed or by some, but not all, of the coils being opened.

10. The method of claim 1, further comprising:

routing a test current through at least one of the coils independently; and

measuring a voltage across the at least one coil that is required to support the test current.

11. The method of claim 1, further comprising:

routing a test current to at least one of the coils independently; and

receiving, via telemetry at the external charger, an indication from the at least one implantable medical device of coupling between the at least one coil and the at least one implantable medical device.

12. A method for charging at least one implantable medical device using an external charger comprising a plurality of coils, the method comprising:

differently activating the plurality of coils in the external charger to generate a magnetic charging field that is radially asymmetric, wherein the plurality of coils are differently activated in accordance with coupling parameters each indicative of the coupling between one of the coils and the at least one implantable medical device.

13. The method of claim 12, wherein the plurality of coils comprises one primary coil and one or more customization coils.

14. The method of claim 13, wherein the plurality of coils are positioned radially symmetrically about a main axis of the primary coil.

15. The method of claim 13, wherein the coils are differently activated by some, but not all, of the coils being coupled in series with the primary coil.

16. The method of claim 13, wherein increasing a current that is supplied to at least one of the customization coils decreases a strength of the magnetic charging field near the at least one customization coil.

17. The method of claim 13, wherein increasing a current that is supplied to at least one of the customization coils increases a strength of the magnetic charging field near the at least one customization coil.

18. The method of claim 12, wherein the coils are differently activated by carrying different customization currents.

19. The method of claim 12, further comprising:

routing a test current through at least one of the coils independently; and

measuring a voltage across the at least one coil that is required to support the test current.

20. The method of claim 12, further comprising:

routing a test current to at least one of the coils independently; and

receiving, via telemetry at the external charger, an indication from the at least one implantable medical device of coupling between the at least one coil and the at least one implantable medical device.