Battery life optimiser

• US 20050077872A1
• Filed: 10/13/2004
• Published: 04/14/2005
• Est. Priority Date: 10/13/2003
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Single, Peter Scott
• Granted Patent: US 8,334,677 B2
• Time in Patent Office: Days
• US Class Current: 320/114
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/0069 Charging or discharging for charge maintenance, battery initiation or rejuvenation

Abstract

A method of controlling charging of a battery (16) of a totally implantable auditory prosthesis and a control system (50) therefor. The method comprises determining a first charge related characteristic of the battery (16) such as the predetermined minimum amount of charge (58), and a second charge related battery characteristic such as the preset charge level or charge rate of the battery (16). The method further comprises detecting when a charge cycle of the battery (16) commences and monitoring where the charge level of the battery (16) is in relation to the first charge related battery characteristic when the charge cycle commences and adjusting the second charge related battery characteristic depending on the relationship between the charge level and the first charge related battery characteristic at the commencement of the charge cycle. The control system and method has the potential to increase the operational life of the battery (16).

Claims

1. A method of controlling charging of a battery of a totally implantable auditory prosthesis, the method comprising:

determining a first charge related battery characteristic;

determining a second charge related battery characteristic;

detecting when a charge cycle of the battery commences; and

monitoring where the charge level of the battery is in relation to the first charge related battery characteristic when the charge cycle commences and adjusting the second charge related battery characteristic depending on the relationship between the charge level and the first charge related battery characteristic at the commencement of the charge cycle.

2. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 1 wherein the first charge related battery characteristic is a predetermined minimum amount of charge contained in the battery.

3. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 1 wherein the first charge related battery characteristic is a predetermined minimum amount of charge contained in the battery and the second charge related battery characteristic is a preset charge level of the battery.

4. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 3 wherein the preset charge level is lower than a maximum battery charge of the battery.

5. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 4 wherein when a charge cycle commences, the method further comprises monitoring the charge level of the battery relative to the predetermined minimum amount of charge contained in the battery.

6. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 5 wherein if the charge level at which charging commences is higher than the predetermined minimum amount of charge contained in the battery, the method further comprises lowering the preset charge level.

7. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 5 wherein if the charge cycle at which charging commences is lower than the predetermined minimum amount of charge contained in the battery, the method further comprises, at least initially, increasing the preset charge level.

8. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 2, further comprising setting the predetermined minimum amount of charge contained in the battery to be a voltage corresponding to a charge required for use of the implant for a predetermined period of time.

9. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 8 wherein the period of time is a complete day, i.e. a 24 hour period.

10. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 2 wherein the second charge related battery characteristic is a charge rate of the battery.

11. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 10 further comprising adjusting the rate of charge of the battery depending on the charge level of the battery relative to the predetermined minimum amount of charge contained in the battery.

12. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 11 wherein if the charge level is lower than the predetermined minimum amount of charge, the method further comprises increasing the charge rate.

13. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 11 wherein if the charge level is above the predetermined minimum amount of charge, the method further comprises decreasing the charge rate.

14. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 3 wherein the method further comprises adjusting the amount of charge normally stored in the battery.

15. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 14 wherein the amount of charge normally stored in the battery is adjusted using feedback control.

16. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 10 wherein the charge rate of the battery is adjusted using feedback control.

17. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 15, wherein the degree of adjustment is related to the predetermined minimum amount of charge of the battery.

18. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 17 wherein the degree of adjustment is between about 1%-10%, more particularly, between about 3%-7% and, optimally, about 5% of the predetermined minimum amount of charge of the battery.

19. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 17 further comprising adjusting the predetermined minimum amount of charge of the battery to take into account ageing of the battery.

20. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 19 wherein the adjustment of the predetermined minimum amount of charge is automatic.

21. The method of controlling charging of a battery of a totally implantable auditory prosthesis of claim 20 wherein the method comprises creating a look-up table in an electronic memory of the implant that provides the predetermined minimum amount of charge for each preset charge level or charge rate, as the case may be, so that, when the preset charge level or charge rate is updated, so is the predetermined minimum amount of charge.

22. A control system for controlling charging of a battery of a totally implantable auditory prosthesis, the control system comprising:

a controller for controlling charging of the battery, the controller being a programmable controller having data relating to a first charge related battery characteristic and a second charge related battery characteristic and for adjusting the second charge related battery characteristic dependent upon where a charge level of the battery is relative to the first charge related battery characteristic when a charging cycle commences; and

a switching arrangement for switching a charging source into charging communication with the battery when charging of the battery is required.

23. The control system of claim 22 wherein the switching arrangement is a switch controlled by the controller.

24. The control system of claim 23 wherein the charging source includes a radio frequency (RF) link which provides charging to the battery when required and/or power to the implant.

25. The control system of claim 24 wherein the switch is connected between the RF link and the battery and is closed under the action of the controller when the battery of the implant requires charging.

26. The control system of claim 22, wherein the control system includes an analog-to-digital converter for converting a battery voltage to a number to be fed to the controller.

27. The control system of claim 22, wherein the controller detects when charging of the battery has commenced.

28. The control system of claim 22, wherein the auditory prosthesis is a cochlear implant.