Power Circuitry for an Implantable Medical Device Using a DC-DC Converter

• US 20110276110A1
• Filed: 04/14/2011
• Published: 11/10/2011
• Est. Priority Date: 05/07/2010
• Status: Abandoned Application

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Whitehurst, Todd, Carbunaru, Rafael, Parramon, Jordi
• Application Number:
  US13/086,549
• Publication Number:
  US 20110276110A1
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02M 3/33592 having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

Improved power circuitry for charging a battery in an implantable medical device is disclosed. The improved power circuitry uses a DC-DC converter positioned between the rectifier and the battery in the implant to be charged, and operates to boost the voltage produced by the rectifier to a higher compliance voltage used to charge the battery. Because the rectifier can now produce a smaller DC voltage, the AC voltage preceding the rectifier (the coil voltage), can also be lessened. Lowering the coil voltage reduces the amount of heat generated by the coil, which reduces the overall heat generated by the implant during receipt of a magnetic charging field from an external charger during a charging session, which improves patient safety. Additionally, a reduced coil voltage means that the external charger can reduce the intensity of the magnetic charging field, which also reduces heat generated in the external charger during the charging session.

Claims

1. An implantable medical device, comprising:

a coil for receiving a magnetic charging field from an external charger, the magnetic charging field inducing an AC voltage in the coil;

a rectifier for producing a first DC voltage from the AC voltage;

a converter for producing a second DC voltage from the first DC voltage, wherein the second DC voltage is higher than the first DC voltage, and wherein the converter is adjustable to adjust the magnitude of the second DC voltage; and

a battery, wherein the second DC voltage provides power to charge the battery.

2. The device of claim 1, wherein the converter comprises a charge pump.

4. The device of claim 1, wherein the converter comprises an inductor.

6. The device of claim 1, wherein the second DC voltage provides power directly to the battery to charge the battery.

7. The device of claim 1, wherein the second DC voltage provides power indirectly to the battery through a conditioning circuit which provides a charging current to charge the battery.

8. The device of claim 1, further comprising a conditioning circuit between the converter and the battery.

9. The device of claim 1, wherein the rectifier comprises a half- or full-wave rectifier.

10. The device of claim 1, further comprising at least one electrode coupled to the implantable medical device for providing electrical stimulation to a patient'"'"'s tissue.

11. The device of claim 1, wherein the coil is further configured to communicate data to the external charger during receipt of the magnetic charging field.

3. (canceled)

5. (canceled)

12. An implantable medical device, comprising:

a coil for receiving a magnetic charging field from an external charger, the magnetic charging field inducing an AC voltage in the coil;

a rectifier for producing a first DC voltage from the AC voltage;

a converter for producing a second DC voltage from the first DC voltage, wherein the second DC voltage is higher than the first DC voltage, and wherein the converter is adjustable to adjust the magnitude of the second DC voltage;

a conditioning circuit for receiving the DC voltage and for producing a battery charging current; and

a battery for receiving the battery charging current.

13. The device of claim 12, wherein the converter comprises a charge pump.

15. The device of claim 12, wherein the converter comprises an inductor.

17. The device of claim 12, wherein the conditioning circuitry implements a charging scheme for varying the battery charging current over time.

18. The device of claim 12, wherein the rectifier comprises a half- or full-wave rectifier.

19. The device of claim 12, further comprising at least one electrode coupled to the implantable medical device for providing electrical stimulation to a patient'"'"'s tissue.

20. The device of claim 12, wherein the coil is further configured to communicate data to the external charger during receipt of the magnetic charging field.

14. (canceled)

16. (canceled)