POWER TRANSFER TO A MEDICAL IMPLANT LOCATED ADJACENT TISSUE WHILE PREVENTING SHORT CIRCUITS THROUGH THE TISSUE

• US 20120215309A1
• Filed: 02/17/2011
• Published: 08/23/2012
• Est. Priority Date: 02/17/2011
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Saldanha, Andrew, Markey, Mathew R.
• Granted Patent: US 8,615,303 B2
• Time in Patent Office: Days
• US Class Current: 623/10
• 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 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 3/06 using resistors or capacitors, e.g. potential divider
• CPC Class Codes: H02M 3/33523 with galvanic isolation between input and output of both the power stage and the feedback loop

Abstract

A medical implant, including a first power storage device, a first switching circuit for receiving power and transferring the received power from an implant connector electrically connected to the medical implant to the first power storage device in a first power transfer stage, a second power storage device, and a second switching circuit for transferring power from the first power storage device to the second power storage device in a second power transfer stage.

Claims

1. A medical implant comprising:

a first power storage device;

a first switching circuit for receiving power and transferring the received power from an implant connector electrically connected to the medical implant to the first power storage device in a first power transfer stage;

a second power storage device; and

a second switching circuit for transferring power from the first power storage device to the second power storage device in a second power transfer stage.

2. A medical implant as claimed in claim 1, further comprising:

a switching circuit control system configured to;

control the first and second switching circuits so that the first and second power storage devices are not in electrical communication with the implant connector when the first power storage device is in electrical communication with the second power storage device during the second power transfer stage; and

control the first and second switching circuits so that the first power storage device is not in electrical communication with the second power storage device when the first power storage device is in electrical communication with the implant connector during the first power transfer stage.

3. A medical implant as claimed in claim 1 wherein:

the second switching circuit is non-conductive when the first switching circuit is conductive and the first switching circuit is non-conductive when the second switching circuit is conductive.

4. A medical implant as claimed in claim 3 wherein:

the implant connector is a two-wire connection for carrying a signal comprising at least a power component.

5. A medical implant as claimed in claim 4 wherein:

the first switching circuit is conductive in a first and second phase of the signal and the second switching circuit is conductive in a third phase of the signal.

6. A medical implant as claimed in claim 4 wherein:

the first switching circuit comprises four switches; and

the second switching circuit comprises two switches.

7. A medical implant as claimed in claim 6 wherein:

the first power storage device is a capacitor; and

the second power storage device is a capacitor.

8. A medical implant as claimed in claim 1, wherein:

a switching circuit control system configured to;

control the first and second switching circuits so that the second power storage device is charged with power delivered to the first power storage device from the implant connector without the second power storage device being in electrical communication with the implant connector.

9. A medical implant as claimed in claim 4 wherein:

the implant connector includes decoupling capacitors in electrical communication with the first switching circuit.

10. A medical implant as claimed in claim 1, wherein:

the medical implant is a stimulator, or a receiver/stimulator of a cochlear implant.

11. A medical implant system comprising:

a first medical implant contained in a first hermetically sealed housing;

a second medical implant contained in a second hermetically sealed housing; and

an electrical connection between the first and second medical implants extending between the two housings, wherein the first medical implant comprises;

a first power storage device;

a power storage interface configured to place the first power storage device into electrical communication with the electrical connection,

wherein the second medical implant comprises;

a second power storage device;

a first switching circuit configured to receive and transfer power received from the electrical connection to the second power storage device in a first power transfer stage;

a third power storage device; and

a second switching circuit configured to receive and transfer power from the second power storage device to the third power storage device in a second power transfer stage.

12. A medical implant system as claimed in claim 11 wherein:

the medical implant system is a cochlear implant system.

13. A medical implant system as claimed in claim 12 wherein:

the first medical implant is an implantable power module and the second medical implant is a stimulator and/or a receiver/stimulator of the cochlear implant system.

14. A medical implant system as claimed in claim 13 further comprising:

an external module configured to transcutaneously transmit power to the implantable power module, wherein the first implantable power module includes a power storage device configured to store power transmitted from the external module.

15. A medical implant system as claimed in claim 14 wherein:

the external module includes a sound processor.

16. A medical implant system as claimed in claim 11 wherein:

the electrical connection comprises one or more wires extending between the first module and the second module.

17. A method of transferring power between a first medical implant and a second medical implant connected by an electrical connection, the method comprising:

receiving power from the first medical implant via the electrical connection at the second medical implant;

transferring at least a portion of the received power to a first power storage device of the second medical implant via a first switching circuit during a first power transfer stage and storing the received power in the first power storage device; and

transferring at least a portion of the stored power stored on the first power storage device to a second power storage device of the second medical implant via a second switching circuit during a second power transfer stage.

18. A method as claimed in claim 17 wherein:

the step of transferring the at least a portion of the power via the electrical connection to the first power storage device is performed when the first switching circuit is closed and the second switching circuit is open.

19. A method as claimed in claim 18 wherein:

the step of transferring the at least a portion of the power stored in the first power storage device to the second power storage device is performed when the first switching circuit is open and the second switching circuit is closed.

20. A method as claimed in claim 17, further comprising:

controlling the first and second switching circuits so that the first and second power storage devices are not in electrical communication with the electrical connection when the first power storage device is in electrical communication with the second power storage device during the second power transfer stage; and

controlling the first and second switching circuits so that the first power storage device is not in electrical communication with the second power storage device when the first power storage device is in electrical communication with the electrical connection during the first power transfer stage.