Systems and methods for providing power to a battery in an implantable stimulator

• US 7,428,438 B2
• Filed: 01/25/2005
• Issued: 09/23/2008
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Carbunaru, Rafael, Marnfeldt, Goran N., Parramon, Jordi, Ozawa, Robert D.
• Primary Examiner(s): Sykes; Angela
• Assistant Examiner(s): STOKLOSA, JOSEPH A
• Application Number:
  US11/043,642
• Publication Number:
  US 20050131495A1
• Time in Patent Office: 1,337 Days
• Field of Search: 607 30- 31, 607 60- 61, 607 32- 33
• US Class Current: 607/61
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/3727 characterised by the modulation technique
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/37288 Communication to several implantable medical devices within one patient
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04L 27/02 Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation H04L27/32 takes precedence
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence

Abstract

An exemplary system for providing power to a rechargeable battery in an implantable stimulator includes a first coil configured to emit a first magnetic field, a coil in the stimulator configured to receive the first magnetic field, and a zero volt recovery (ZVR) circuit in the stimulator configured to use the first magnetic field to cause the coil in the stimulator to be tuned to a frequency of a second magnetic field. The second magnetic field is used to provide the power to recharge the battery. An exemplary method of providing power to recharge a battery in an implantable stimulator includes transmitting a first magnetic field used to provide the power to recharge the battery, transmitting a second magnetic field; and using the second magnetic field to cause a coil in the stimulator to be tuned to a frequency of the first magnetic field.

Claims

1. A system for providing power to a rechargeable battery in an implantable stimulator, said system comprising:

a first coil configured to emit a first magnetic field;

a second coil in said stimulator configured to receive said first magnetic field; and

a zero volt recovery (ZVR) circuit in said stimulator configured to use said first magnetic field to cause said second coil in said stimulator to be tuned to a frequency of a second magnetic field, said second magnetic field used to provide said power to said battery.

2. The system of claim 1, wherein said first magnetic field has a frequency substantially equal to a self-resonance frequency of said second coil in said simulator.

3. The system of claim 1, wherein said frequency of said first magnetic field is substantially equal to 1.5 megahertz.

4. The system of claim 1, wherein said stimulator comprises a front end circuit having a number of transistor switches, each of said transistor switches being in an ON state or an OFF state, wherein said states of said transistor switches select a mode of operation of said stimulator out of a number of modes of operation, said number of modes of operation including a charging mode wherein said battery is charged with said second magnetic field.

5. The system of claim 4, wherein said number of modes of operation further includes a step-up mode, a frequency shift keying (FSK) receiving mode, an on-off keying(OOK) receiving mode, and a transmitting mode.

6. The system of claim 4, wherein said ZVR circuit comprises an over voltage protection circuit configured to provide over voltage protection during any of said number of modes of operation.

7. The system of claim 4, wherein said ZVR circuit uses said first magnetic field to turn ON one or more of said transistor switches such that said mode of operation of said stimulator is said charging mode.

8. The system of claim 7, wherein said ZVR circuit uses said first magnetic field to turn OFF one or more of said transistor switches such that said mode of operation of said stimulator is said charging mode.

9. The system of claim 7, wherein said ZVR circuit comprises an output gate voltage generation circuit configured to generate a voltage used to turn said one or more of said transistor switches to said ON state.

10. The system of claim 1, wherein said ZVR circuit comprises a trickle charge circuit configured to trickle charge said battery.

11. The system of claim 1, wherein said ZVR circuit comprises one or more asymmetric static random access memory (SRAM) cells.

12. The system of claim 1, wherein said frequency of said second magnetic field is substantially equal to 127 kilohertz.

13. The system of claim 1, wherein said system further comprises a third coil, said third coil configured to emit said second magnetic field.

14. An implantable stimulator, comprising:

a rechargeable battery;

a coil configured to receive a first magnetic field; and

a zero volt recovery (ZVR) circuit configured to use said first magnetic field to cause said coil to be tuned to a frequency of a second magnetic field, said second magnetic field used to provide power to said battery.

15. The stimulator of claim 14, wherein said first magnetic field has a frequency substantially equal to a self-resonance frequency of said coil.

16. The stimulator of claim 14, wherein said frequency of said first magnetic field is substantially equal to 1.5 megahertz.

17. The stimulator of claim 14, further comprising:

a front end circuit having a number of transistor switches, each of said transistor switches being in an ON state or an OFF state;

wherein said states of said transistor switches select a mode of operation of said stimulator out of a number of modes of operation, said number of modes of operation including a charging mode wherein said battery is charged with said second magnetic field.

18. The stimulator of claim 17, wherein said number of modes of operation further includes a step-up mode, a frequency shift keying (FSK) receiving mode, an on-off keying (OOK) receiving mode, and a transmitting mode.

19. The stimulator of claim 17, wherein said ZVR circuit comprises an over voltage protection circuit configured to provide over voltage protection during any of said number of modes of operation.

20. The stimulator of claim 17, wherein said ZVR circuit uses said first magnetic field to turn ON one or more of said transistor switches such that said mode of operation of said stimulator is said charging mode.

21. The stimulator of claim 20, wherein said ZVR circuit uses said first magnetic field to turn OFF one or more of said transistor switches such that said mode of operation of said stimulator is said charging mode.

22. The stimulator of claim 20, wherein said ZVR circuit comprises an output gate voltage generation circuit configured to generate a voltage used to turn said one or more of said transistor switches to said ON state.

23. The stimulator of claim 14, wherein said ZVR circuit comprises a trickle charge circuit configured to trickle charge said battery.

24. The stimulator of claim 14, wherein said ZVR circuit comprises one or more asymmetric static random access memory (SRAM) cells.

25. The stimulator of claim 14, wherein said frequency of said second magnetic field is substantially equal to 127 kilohertz.

26. A device configured to provide power to a rechargeable battery in an implantable stimulator, said device comprising:

a first coil configured to emit a first magnetic field of a first frequency used by a zero volt recovery (ZVR) circuit in said stimulator to cause a stimulator coil in said stimulator to be tuned to a frequency of a second magnetic field of a second frequency, said second magnetic field configured to provide said power to said battery; and

a second coil configured to emit said second magnetic field.

27. The device of claim 26, wherein said first frequency is substantially equal to a self-resonance frequency of said stimulator coil in said simulator.

28. The device of claim 26, wherein said first frequency is substantially equal to 1.5 megahertz.

29. The device of claim 26, further comprising control circuitry to activate the first coil before the second coil.

30. The device of claim 26, wherein said second frequency is substantially equal to 127 kilohertz.

31. A method of providing power to a rechargeable battery in an implantable stimulator, said method comprising:

transmitting a first magnetic field used to provide said power to said battery;

transmitting a second magnetic field; and

using said second magnetic field to cause a coil in said stimulator to be tuned to a frequency of said first magnetic field.

32. The method of claim 31, wherein said second magnetic field has a frequency substantially equal to a self-resonance frequency of said coil in said simulator.

33. The method of claim 31, wherein said frequency of said second magnetic field is substantially equal to 1.5 megahertz.

34. The method of claim 31, wherein said step of using said second magnetic field to cause said coil in said stimulator to be tuned to said frequency of said first magnetic field comprises controlling a state of a number of transistor switches with said second magnetic field.

35. The method of claim 31, further comprising trickle charging said battery.

36. The method of claim 31, wherein said frequency of said first magnetic field is substantially equal to 127 kilohertz.

37. A system for providing power to a rechargeable battery in an implantable stimulator, said system comprising:

means for transmitting a first magnetic field used to provide said power to said battery;

means for transmitting a second magnetic field; and

means for using said second magnetic field to cause a coil in said stimulator to be tuned to a frequency of said first magnetic field.

38. The system of claim 37, wherein said means for using said second magnetic field to cause said coil in said stimulator to be tuned to said frequency of said first magnetic field comprises means for controlling a state of a number of transistor switches with said second boost field.