Power suppy for a cochlear implant

• US 20040049243A1
• Filed: 07/07/2003
• Published: 03/11/2004
• Est. Priority Date: 01/24/2001
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Seligman, Peter Misha
• Granted Patent: US 7,157,808 B2
• Time in Patent Office: Days
• US Class Current: 607/57
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 7/0024 Parallel/serial switching of connection of batteries to charge or load circuit
• CPC Class Codes: H02J 7/0063 with circuits adapted for supplying loads from the battery
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H04R 25/606 acting directly on the eardrum, the ossicles or the skull, e.g. mastoid, tooth, maxillary or mandibular bone, or mechanically stimulating the cochlea, e.g. at the oval window

Abstract

A power supply control system for use with a tissue stimulating prosthesis, such as a cochlear implant. The power supply control system comprises a first battery (31), a second battery (32), at least a third battery (33), and a switching system (36). The first and second batteries (31,32) are electrically connected in series to provide power to the prosthesis, while the third battery (33) is electrically connectable through the switching means (36) in parallel with either the first battery (32). The third battery (33) is electrically connected by the control system in parallel with whichever one of said first battery (31) or said second battery (32) has lowest voltage.

Claims

1. A power supply for an electrically powered device, the power supply comprising:

a first battery;

a second battery;

at least a third battery; and

a switching means;

the first and second battery being electrically connected in series, and the at least a third battery being electrically connectable through the switching means in parallel with either the first battery or the second battery;

wherein the third battery is connected in parallel with whichever of the first and second batteries is exhibiting lesser performance.

2. The power supply of claim 1 wherein the third battery is connected in parallel by the switching means with whichever of the first and second batteries has the lowest voltage.

3. The power supply of claim 1 or claim 2 wherein the switching means comprises an analog changeover switch.

4. The power supply of claim 2 wherein the power supply further comprises a comparator that compares the mid-point from a voltage divider, such that when the mid-point of the batteries indicates a mismatch, the power supply operates the switch to connect the third battery in parallel with whichever of the first or second batteries has the lowest voltage.

5. The power supply of claim 4 wherein the comparator is a low power comparator.

6. The power supply of claim 2, 4 or 5 wherein the switching means operates when the voltage of the battery of the first and second batteries having the lowest voltage is at or below a predetermined value below the voltage of the other battery of the first and second batteries.

7. The power supply of claim 6 wherein the switching means operates when the voltage of the battery having the lowest voltage is at least substantially 4 mV less than the voltage of the other battery of the first and second batteries.

8. The power supply of any one of the preceding claims wherein at least one of the batteries of the power supply is rechargeable.

9. A power supply control system for use with a tissue stimulating prosthesis, the power supply control system comprising:

a first battery;

a second battery;

at least a third battery; and

a switching means;

the first and second battery being electrically connected in series to provide power to the prosthesis, and the at least a third battery being electrically connectable through the switching means in parallel with either the first battery or the second battery;

wherein the third battery is electrically connected by the control system in parallel with whichever one of said first battery or said second battery has the lowest voltage.

10. The power supply control system of claim 9 wherein the switching means comprises an analog changeover switch.

11. The power supply control system of claim 9 or 10 wherein the power supply control system further comprises a comparator that compares the midpoint from a voltage divider positioned across the first and second batteries, such that when the mid-point of the batteries indicates a mismatch, the power supply control system operates the switching means to connect the third battery in parallel with whichever of the first or second batteries has the lowest voltage.

12. The power supply control system of any one of claims 9 to 11 wherein the switching means operates only when the voltage of the battery of the first and second batteries having the lowest voltage is at or below a predetermined value below the voltage of the other battery of the first and second batteries.

13. The power supply control system of claim 12 wherein the switching means operates when the voltage of the battery of the first and second batteries having the lowest voltage is at least substantially 4 mV less than the voltage of the other battery of the first and second batteries.

14. The power supply control system of any one of claims 9 to 13 wherein the tissue-stimulating prosthesis comprises a cochlear implant.

15. The power supply control system of claim 14 wherein the cochlear implant comprises an external component that houses a speech processor.

16. The power supply control system of claim 15 wherein the external component has a case, the power supply being mounted within the case.

17. The power supply control system of any one of claims 9 to 16 wherein the first, second, and at least the third battery each comprise a zinc-air cell.

18. A power supply control system for use with a tissue stimulating prosthesis, the power supply control system comprising:

a first battery;

a second battery;

at least a third battery; and

a switching means;

the first and second battery being electrically connected in series to provide power to the prosthesis, and the at least a third battery being electrically connectable through the switching means in parallel with either the first battery or the second battery;

wherein the third battery is electrically connected by the control system in parallel with one of said first battery or said second battery following detection by the control system that the voltage of said first battery or said second battery is below a predetermined threshold.

19. The power supply control system of claim 18 wherein the switching means comprises an analog changeover switch.

20. The power supply control system of claim 18 or 19 wherein the power supply control system further comprises a comparator that compares the midpoint from a voltage divider positioned across the first and second batteries, such that when the mid-point of the batteries indicates a mismatch, the power supply control system operates the switching means to connect the third battery in parallel with whichever of the first or second batteries has the lowest voltage.

21. The power supply control system of any one of claims 18 to 20 wherein the switching means operates only when the voltage of the battery of the first and second batteries having the lowest voltage is at or below a predetermined value below the voltage of the other battery of the first and second batteries.

22. The power supply control system of claim 21 wherein the switching means operates when the voltage of the battery of the first and second batteries having the lowest voltage is at least substantially 4 mV less than the voltage of the other battery of the first and second batteries.

23. The power supply control system of any one of claims 18 to 22 wherein the tissue-stimulating prosthesis comprises a cochlear implant.

24. The power supply control system of claim 23 wherein the cochlear implant comprises an external component that houses a speech processor.

25. The power supply control system of claim 24 wherein the external component has a case, the power supply being mounted within the case.

26. The power supply control system of any one of claims 18 to 25 wherein the first, second, and at least the third battery each comprise a zinc-air cell.

27. A power supply control system for use with a tissue stimulating prosthesis, the power supply control system comprising:

a first battery;

a second battery connected in series with the first battery to provide power to the prosthesis; and

a third battery being electrically connectable via switching means in parallel with either the first battery or the second battery;

wherein the control system controls the switching means to electrically connect the third battery in parallel with said first battery or said second battery based on a determination by the control system that the operation of said first battery or said second battery is below a predetermined threshold.

28. The power supply control system of claim 27 wherein the control system is operable to measure a voltage of the first battery and a voltage of the second battery in order to make the determination of which of said first battery and said second battery are below the predetermined threshold.

29. The power supply control system of claim 27 or 28 wherein the switching means comprises an analog changeover switch.

30. The power supply control system of any one of claims 27 to 29 wherein the power supply control system further comprises a comparator that compares the mid-point from a voltage divider positioned across the first and second batteries, such that when the mid-point of the batteries indicates a mismatch, the power supply control system operates the switching means to connect the third battery in parallel with whichever of the first or second batteries has the lowest voltage.

31. The power supply control system of any one of claims 27 to 30 wherein the switching means operates only when the voltage of the battery of the first and second batteries having the lowest voltage is at or below a predetermined value below the voltage of the other battery of the first and second batteries.

32. The power supply control system of claim 31 wherein the switching means operates when the voltage of the battery of the first and second batteries having the lowest voltage is at least substantially 4 mV less than the voltage of the other battery of the first and second batteries.

33. The power supply control system of any one of claims 27 to 32 wherein the tissue-stimulating prosthesis comprises a cochlear implant.

34. The power supply control system of claim 33 wherein the cochlear implant comprises an external component that houses a speech processor.

35. The power supply control system of claim 34 wherein the external component has a case, the power supply being mounted within the case.

36. The power supply control system of any one of claims 27 to 35 wherein the first, second, and at least the third battery each comprise a zinc-air cell.

37. A method of operating a power supply, the method comprising the steps of:

electrically connecting a first battery and a second battery in series; and

electrically connecting a third battery in parallel with whichever battery of the first battery and the second battery exhibits worse performance.

38. The method of claim 37 further comprising the step of measuring the performance of the first battery and the second battery by determining the voltage of each of the first and second batteries.

39. The method of claim 37 or claim 38 further comprising the step of disconnecting the third battery from a parallel connection with either of the first battery or the second battery, prior to determining the performance of the first battery and the second battery.

40. A method of operating a power supply for a tissue-stimulating prosthesis, the method comprising the steps of:

electrically connecting a first battery and a second battery in series; and

electrically connecting a third battery in parallel with whichever battery of the first battery and the second battery exhibits worse performance.

41. The method of claim 40 further comprising the step of measuring the performance of the first battery and the second battery by determining the voltage of each of the first and second batteries.

42. The method of claim 40 or claim 41 further comprising the step of disconnecting the third battery from a parallel connection with either of the first battery or the second battery, prior to determining the performance of the first battery and the second battery.

43. A power supply for an electrically powered device, the power supply comprising:

a first plurality of batteries;

a second plurality of batteries; and

a switching means;

the first plurality of batteries being electrically connected in series, and at least one of the second plurality of batteries being electrically connectable through the switching means in parallel with at least one of the first plurality of batteries;

wherein said at least one of the second plurality of batteries is connected in parallel with whichever of said at least one of the first plurality of batteries is exhibiting lesser performance.

44. A power supply control system for use with a tissue stimulating prosthesis, the power supply control system comprising:

a first plurality of batteries;

a second plurality of batteries; and

a switching means;

the first plurality of batteries being electrically connected in series to provide power to the prosthesis, and at least one of the second plurality of batteries being electrically connectable through the switching means in parallel with at least one of the first plurality of batteries;

wherein the at least one of the second plurality of batteries is electrically connected by the control system in parallel with at least one of said first plurality of batteries following detection by the control system that the voltage of said at least one of said first plurality of batteries is below a predetermined threshold.