Power supply for a cochlear implant

• US 7,157,808 B2
• Filed: 01/24/2002
• Issued: 01/02/2007
• Est. Priority Date: 01/24/2001
• Status: Expired due to Fees

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Seligman, Peter Misha
• Primary Examiner(s): Sircus; Brian
• Assistant Examiner(s): DESCHERE, ANDREW M
• Application Number:
  US10/250,705
• Publication Number:
  US 20040049243A1
• Time in Patent Office: 1,804 Days
• Field of Search: 320/138, 307/48, 307/50, 307/54, 307/63, 307/71, 307/66, 307/130, 607/29, 607/34, 607/55, 607/56, 607/57
• US Class Current: 307/48
• 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 comprising:

a first battery;

a second battery;

at least a third battery; and

a switching means;

wherein, the first and second battery being electrically connected in series, and the at least a third battery being electrically connected by the switching means in parallel with one of the first battery or the second battery which has a lower voltage,

when the lower voltage is below the voltage of the other one of the first and second batteries by a predetermined value.

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

3. The power supply of claim 1 further comprising a comparator that compares a mid-point voltage from a voltage divider with the predetermined value, such that when a mid-point voltage of the batteries indicates a mismatch with the predetermined value, the power supply operates the switching means to connect the third battery in parallel with the one of the first or second batteries which has the lower voltage.

4. The power supply of claim 3 wherein the comparator is a low power comparator.

5. The power supply of claim 1 wherein the predetermined value is at least 4 mV.

6. The power supply of claim 1 wherein at least one of the batteries of the power supply is rechargeable.

7. A power supply control system for use with a tissue stimulating prosthesis comprising:

a first battery;

a second battery;

at least a third battery; and

a switching means

wherein, 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 connected by the switching means in parallel with one of the first battery or the second battery which has a lower voltage,

when the lower voltage is below the voltage of the other one of the first and second batteries by a predetermined value.

8. The power supply control system of claim 7 wherein the switching means comprises an analog changeover switch.

9. The power supply control system of claim 7 further comprising a comparator that compares a mid-point voltage from a voltage divider positioned across the first and second batteries with the predetermined value, such that when a mid-point voltage of the batteries indicates a mismatch, the power supply control system operates the switching means to connect the third battery in parallel with the one of the first or second batteries which has the lower voltage.

10. The power supply control system of claim 7, wherein the predetermined value is at least 4 mV.

11. The power supply control system of claim 7 wherein the tissue-stimulating prosthesis comprises a cochlear implant.

12. The power supply control system of claim 11 wherein the cochlear implant comprises an external component that houses a speech processor.

13. The power supply control system of claim 12 wherein the external component has a case, the power supply being mounted within the case.

14. The power supply control system of claim 7 wherein the first, second, and at least the third battery each comprise a zinc-air cell.

15. A power supply control system for use with a tissue stimulating prosthesis comprising:

a first battery;

a second battery;

at least a third battery; and

a switching means

wherein, 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 connected by the switching means in parallel with either one of the first battery or the second battery which has a lower voltage,

when the lower voltage is below the voltage of the other one of the first and second batteries by a predetermined value.

16. The power supply control system of claim 15 wherein the switching means comprises an analog changeover switch.

17. The power supply control system of claim 15 further comprising a comparator that compares a mid-point voltage from a voltage divider positioned across the first and second batteries with the predetermined value, such that when a mid-point voltage of the batteries indicates a mismatch, the power supply control system operates the switching means to connect the third battery in parallel with the one of the first or second batteries which has the lower voltage.

18. The power supply control system of claim 15 wherein the predetermined value 4 mV.

19. The power supply control system of claim 15 wherein the tissue-stimulating prosthesis comprises a cochlear implant.

20. The power supply control system of claim 19 wherein the cochlear implant comprises an external component that houses a speech processor.

21. The power supply control system of claim 20 wherein the external component has a case, the power supply being mounted within the case.

22. The power supply control system of claim 15 wherein the first, second, and at least the third battery each comprise a zinc-air cell.

23. 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 in parallel with one of the first battery or the second battery by a switching means;

wherein the control system controls the switching means to electrically connect the third battery in parallel with said one of the first battery or the 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 voltage value and

wherein the switching means operates only when the voltage of the battery of the first and second batteries having a lower voltage is below the voltage of the other battery of the first and second batteries by the predetermined voltage value.

24. The power supply control system of claim 23 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 voltage value.

25. The power supply control system of claim 23 wherein the switching means comprises an analog changeover switch.

26. The power supply control system of claim 23 further comprising a comparator that compares a mid-point voltage from a voltage divider positioned across the first and second batteries with the predetermined voltage value, such that when a mid-point voltage of the batteries indicates a mismatch, the power supply control system operates the switching means to connect the third battery in parallel with the one of the first or second batteries which has the lower voltage.

27. The power supply control system of claim 23 wherein the predetermined voltage is at least 4 mV.

28. The power supply control system of claim 23 wherein the tissue-stimulating prosthesis comprises a cochlear implant.

29. The power supply control system of claim 28 wherein the cochlear implant comprises an external component that houses a speech processor.

30. The power supply control system of claim 29 wherein the external component has a case, the power supply being mounted within the case.

31. The power supply control system of claim 23 wherein the first, second, and at least the third battery each comprise a zinc-air cell.