Pressure-Sensitive External Charger for an Implantable Medical Device

• US 20110178576A1
• Filed: 01/19/2010
• Published: 07/21/2011
• Est. Priority Date: 01/19/2010
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Aghassian, Daniel
• Granted Patent: US 8,401,663 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36062 Spinal stimulation
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting

Abstract

An improved external charger for an implantable medical device is disclosed in which charging is at least partially controlled based on a sensed pressure impingent on its case, which pressure is indicative of the pressure between the external charger and a patient'"'"'s tissue. The improved external charger includes pressure detection circuitry coupled to one or more pressure sensors for controlling the external device in accordance with the sensed impingent pressure. The sensed pressure can be used to control charging, for example, by suspending charging, by adjusting a maximum set point temperature for the external charger based on the measured pressure, or by issuing an alert via a suitable user interface. By so controlling the external charger on the basis of the measured pressure, the external charger is less likely to create potentially problematic or uncomfortable conditions for the user.

Claims

1. An external device for wirelessly transmitting energy to an implantable medical device, comprising:

a case;

at least one pressure sensor for sensing a pressure impingent on the case; and

detection circuitry coupled to the at least one pressure sensor for reducing the energy wirelessly transmitted to the implantable medical device in accordance with the sensed impingent pressure.

2. The external device of claim 1, wherein the external device is hand-held, or body-worn, or portable.

3. The external device of claim 1, wherein the wirelessly transmitted energy comprises power for the implantable medical device.

4. The external device of claim 3, wherein the power is used to charge a battery in the implantable medical device.

5. The external device of claim 1, wherein the wirelessly transmitted energy comprises instructions for programming the implantable medical device.

6. The external device of claim 1, wherein reducing the energy wirelessly transmitted to the implantable medical device comprises modifying a maximum set point temperature for the external device.

7. The external device of claim 1, wherein the detection circuit further issues an alert from the external device in accordance with the sensed impingent pressure.

8. The external device of claim 1, wherein reducing the energy wirelessly transmitted to the implantable medical device comprises suspending the wireless transmission to the implantable medical device.

9. An external device for an implantable medical device, comprising:

a hand-held case comprising at least two hard case portions;

a coil for wirelessly transmitting to an implantable medical device;

at least one pressure sensor for sensing a pressure impingent on the at least two hard case portions; and

detection circuitry coupled to the at least one pressure sensor for controlling the external device in accordance with the sensed impingent pressure.

10. The external device of claim 9, further comprising a user interface, and wherein the detection circuit controls the external device by issuing an alert from the user interface.

11. The external device of claim 9, wherein the detection circuit controls the external device by disabling the coil.

12. The external device of claim 9, wherein the external device comprises a plurality of pressure sensors.

13. The external device of claim 9, wherein the at least one pressure sensor is located inside of the case portions.

14. The external device of claim 13, wherein the at least one pressure sensor is mounted to a printed circuit board within the case portions.

15. The external device of claim 9, wherein the at least one pressure sensor is located at a junction between the at least two case portions.

16. The external device of claim 9, wherein the at least one pressure sensor comprises a strain gauge.

17. The external device of claim 9, wherein the detection circuitry receives inverse inputs from two pressure sensors.

18. The external device of claim 9, wherein the case portions are substantially planar, and wherein the sensed pressure is orthogonal to the substantially planar case portions.

19. The external device of claim 9, wherein the detection circuit detects a critical pressure and controls the external device when the critical pressure is exceeded.

20. The external device of claim 19, wherein the critical pressure is adjustable.

21. The external device of claim 9, wherein the detection circuit detects a critical pressure and controls the external device when the critical pressure is exceeded for a set period of time.

22. The external device of claim 9, wherein the detection circuit detects a plurality of pressure ranges and controls the external device in accordance with a detected pressure range.

23. An external charger for wirelessly providing power to an implantable medical device, comprising:

a case;

a coil within the case for wirelessly transmitting power to an implantable medical device;

at least one pressure sensor for sensing a pressure impingent on the case; and

detection circuitry coupled to the at least one pressure sensor for controlling a temperature of the external charger in accordance with the sensed impingent pressure.

24. The external charger of claim 23, wherein the external charger is hand-held, or body-worn, or portable.

25. The external charger of claim 23, wherein the detection circuit controls the temperature by modifying a set point temperature for the external charger.

26. The external charger of claim 23, wherein the detection circuitry controls the temperature by scaling a maximum set point temperature for the external charger inversely with the impingent pressure.

27. The external charger of claim 23, wherein the detection circuit further controls the external charger by disabling the coil in accordance with the sensed impingent pressure.

28. The external charger of claim 23, further comprising a user interface, and wherein the detection circuit further controls the external charger by issuing an alert from the user interface in accordance with the sensed impingent pressure.

29. The external charger of claim 23, wherein the case is substantially planar, and wherein the sensed impingent pressure is orthogonal to the substantially planar case.

30. The external charger of claim 23, wherein the detection circuit detects a critical pressure and controls the temperature when the critical pressure is exceeded.

31. The external charger of claim 23, wherein the detection circuit detects a critical pressure and controls the temperature when the critical pressure is exceeded for a set period of time.

32. The external charger of claim 23, wherein the detection circuit detects a plurality of pressure ranges and controls the temperature in accordance with a detected pressure range.

33. A method for operating an external charger, comprising:

enabling the external charger to wirelessly transmit power to an implanted medical device during a charging session;

monitoring a pressure on the case of the external charger during the charging session; and

suspending the wireless transmission of power during the charging session when the pressure on the case of the external charger exceeds a critical pressure value.

34. The method of claim 33, wherein the critical pressure value is adjustable via a user interface of the external charger.

35. The method of claim 33, wherein the wireless transmission of power is suspended when the pressure on the case of the external charger exceeds the critical pressure value for a first amount of time.

36. The method of claim 33, further comprising resuming the wireless transmission of power during the charging session when the pressure on the case of the external charger falls below the critical pressure value.

37. The method of claim 33, further comprising altering the user when the pressure on the case of the external charger is greater than the critical pressure value for a second time, wherein the second time is less than the first time.

38. A method for operating an external charger, comprising:

enabling the external charger to wirelessly transmit power to an implanted medical device during a charging session;

monitoring a pressure on the case of the external charger during the charging session; and

issuing an alert from the external charger when the pressure on the case of the external charger exceeds a critical pressure.

39. The method of claim 38, wherein the alert is issued when the pressure on the case of the external charger exceeds the critical pressure value for a first time.