Power and data transfer in hearing prostheses

• US 9,724,525 B2
• Filed: 11/17/2014
• Issued: 08/08/2017
• Est. Priority Date: 01/30/2014
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Meskens, Werner
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Patel, Natasha
• Application Number:
  US14/542,877
• Publication Number:
  US 20150209591A1
• Time in Patent Office: 995 Days
• CPC Class Codes: A61N 1/36036 of the outer, middle or inner ear
• CPC Class Codes: A61N 1/36038 Cochlear stimulation
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• 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 50/12 of the resonant type
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: H04R 2225/67 Implantable hearing aids or parts thereof not covered by H04R25/606

Abstract

Embodiments presented herein are generally directed to techniques for separately transferring power and data from an external device to an implantable component of a partially or fully implantable medical device. The separated power and data transfer techniques use a single external coil and a single implantable coil. The external coil is part of an external resonant circuit, while the implantable coil is part of an implantable resonant circuit. The external coil is configured to transcutaneously transfer power and data to the implantable coil using separate (different) power and data time slots. At least one of the external or internal resonant circuit is substantially more damped during the data time slot than during the power time slot.

Claims

1. An implantable medical device, comprising:

an implantable resonant circuit comprising an implantable coil; and

an external resonant circuit comprising an external coil configured to transcutaneously transfer power and data to the implantable coil using separate power time slots and data time slots, respectively,

wherein a peak amplitude of current used to drive the external coil during the data time slots is lower than a peak amplitude of current used to drive the external coil during the power time slots, and wherein at least one of the external or implantable resonant circuit is substantially more damped during the data time slots than during the power time slots.

2. The implantable medical device of claim 1, wherein the external and implantable resonant circuits are resonant tank circuits.

3. The implantable medical device of claim 1, wherein a resonance frequency of the external resonant circuit is adjusted during the data time slots so as to be lower or higher than the resonant frequency of the external resonant circuit during the power time slots.

4. The implantable medical device of claim 1, wherein the implantable coil is connected to an energy rectifier, and wherein the peak amplitude of current used to drive the external coil during the data time slot is such that the energy rectifier does not allow current to pass there through during the data time slots.

5. The implantable medical device of claim 1, wherein the external resonant circuit is connected to one driver bridge that is used to drive the external coil during both the power and data time slots.

6. The implantable medical device of claim 5, further comprising:

a first series circuit comprising a first resistor and a first inductor connected between a first output of the driver bridge and the external resonant circuit;

a second series circuit comprising a second resistor and a second inductor connected between a second output of the driver bridge and the external resonant circuit; and

a switch connected in parallel to the first and second series circuits between the first and second outputs of the driver bridge and the external resonant circuit,

wherein during the data time slots the switch is open so that signals from the first and second outputs of the driver bridge pass through the first and second series circuits, respectively, and wherein during the power time slots the switch is closed so that signals from the first and second outputs of the driver bridge bypass the first and second series circuits.

7. The implantable medical device of claim 1, wherein the external resonant circuit is connected to two or more driver bridges, and wherein different ones of the two or more driver bridges are used to drive the coil during the power and data time slots, respectively.

8. The implantable medical device of claim 7, wherein a first driver bridge is a half H-bridge and at least one additional driver bridge is a full H-bridge.

9. The implantable medical device of claim 7, wherein outputs of a driver bridge that is not used during one of the power or data time slots are placed in a high impedance state.

10. The implantable medical device of claim 7, wherein a first dedicated driver bridge is enabled during the data time slot and a second dedicated driver bridge is enabled during the power time slot.

11. The implantable medical device of claim 7, further comprising:

a data driver bridge;

a first series circuit comprising a first resistor and a first inductor connected between a first output of the data driver bridge and the external resonant circuit;

a second series circuit comprising a second resistor and a second inductor connected between a second output of the data driver bridge and the external resonant circuit; and

at least one power driver bridge directly connected to the external resonant circuit so as to bypass the first and second series circuits,

wherein during the data time slots the data driver bridge is enabled and outputs of the at least one power driver bridge are placed in a high impedance state and wherein during the power time slots the at least one power driver bridge is enabled and the first and second outputs of the data driver bridge are placed in a high impedance state.

12. The implantable medical device of claim 11, wherein the at least one power driver bridge comprises first and second power driver bridges configured to be simultaneously enabled.

13. The implantable medical device of claim 1, further comprising:

a capacitor connected to the implantable coil and forming part of the implantable resonant circuit; and

a resistor connectable in parallel to the capacitor via an implantable switch,

wherein during the data time slots the implantable switch is closed so as to connect the resistor to the implantable resonant circuit to dampen the implantable resonant circuit, and wherein during the power time slots the implantable switch is opened so as to disconnect the resistor from the implantable resonant circuit.

14. The implantable medical device of claim 1, wherein the quality factor of the external resonant circuit is lower during the data slots than during the power time slots to dampen the external resonant circuit during the power time slots.

15. The implantable medical device of claim 7, further comprising:

a first series circuit comprising a first resistor and a first inductor connected between a first output of the first driver bridge and the external resonant circuit;

a second series circuit comprising a second resistor and a second inductor connected between a second output of the first driver bridge and the external resonant circuit;

wherein the second driver bridge is directly connected to the external resonant circuit so as to bypass the first and second series circuits.

16. A method performed by an implantable medical device, comprising:

transcutaneously transmitting data from an external coil of an external resonant circuit to an implantable coil of an implantable resonant circuit in a first set of time slots;

transcutaneously transmitting power from the external coil to the implantable coil in a second set of time slots; and

lowering a peak amplitude of current used to drive the external coil during the first set of time slots relative to the peak amplitude of current used to drive the external coil during the second set of time slots to damp the external resonant circuit during the first set of time slots and lower a quality factor of the external resonant circuit during the first set of time slots relative to the quality factor of the external resonant circuit during the second set of time slots.

17. The method of claim 16, wherein damping the external resonant circuit during the first set of time slots comprises:

adjusting a resonance frequency of the external resonant circuit during the first set of time slot so as to be lower or higher than the resonant frequency of the external circuit during the second set of time slots.

18. The method of claim 16, wherein the implantable resonant circuit comprises an energy rectifier, and wherein the peak amplitude of current used to drive the external coil during the first set of time slot is such that the energy rectifier does not allow current to pass there through during the first set of time slots.

19. The method of claim 16, wherein the external and implantable resonant circuits are resonant tank circuits.

20. The method of claim 16, wherein the external resonant circuit is connected to one driver bridge, and wherein the method further comprises:

driving the external coil with the driver bridge during both the first and second sets of time slots.

21. The method of claim 20, wherein a first series circuit comprising a first resistor and a first inductor is connected between a first output of the driver bridge and the external resonant circuit, a second series circuit comprising a second resistor and a second inductor is connected between a second output of the driver bridge and the external resonant circuit, and a switch is connected in parallel to the first and second series circuits between the first and second outputs of the driver bridge and the external resonant circuit, and wherein the method further comprises:

during the first set of time slots, opening the switch so that signals from the first and second outputs of the driver bridge pass through the first and second series circuits, respectively; and

during the second set of time slots, closing the switch so that signals from the first and second outputs of the driver bridge bypass the first and second series circuits.

22. An implantable medical device, comprising:

an implantable resonant circuit comprising an implantable coil; and

an external resonant circuit comprising an external coil configured to transcutaneously transfer power and data to the implantable coil using separate power time slots and data time slots, respectively;

a capacitor connected to the implantable coil and forming part of the implantable resonant circuit; and

a resistor connectable in parallel to the capacitor via an implantable switch,

wherein during the data time slots the implantable switch is closed so as to connect the resistor to the implantable resonant circuit to dampen the implantable resonant circuit, and

wherein during the power time slots the implantable switch is opened so as to disconnect the resistor from the implantable resonant circuit.

23. The implantable medical device of claim 22, wherein the external and implantable resonant circuits are resonant tank circuits.

24. The implantable medical device of claim 22, wherein a resonance frequency of the external resonant circuit is adjusted during the data time slots so as to be lower or higher than the resonant frequency of the external resonant circuit during the power time slots.

25. The implantable medical device of claim 22, wherein a peak amplitude of current used to drive the external coil during the data time slots is lower than a peak amplitude of current used to drive the external coil during the power time slots.

26. The implantable medical device of claim 25, wherein the implantable coil is connected to an energy rectifier, and wherein the peak amplitude of current used to drive the external coil during the data time slot is such that the energy rectifier does not allow current to pass there through during the data time slots.

27. The implantable medical device of claim 22, wherein the external resonant circuit is connected to one driver bridge that is used to drive the external coil during both the power and data time slots.

28. The implantable medical device of claim 22, wherein the external resonant circuit is connected to two or more driver bridges, and wherein different ones of the two or more driver bridges are used to drive the coil during the power and data time slots, respectively.

29. An implantable medical device, comprising:

an implantable resonant circuit comprising an implantable coil;

an external resonant circuit comprising an external coil configured to transcutaneously transfer power and data to the implantable coil using separate power time slots and data time slots, respectively; and

first and second driver bridges connected to the external resonant circuit, wherein the first driver bridge is enabled during the data time slots to drive the coil during the data time slots and the second driver bridge is enabled during the power time slot to drive the coil during the power time slots,

wherein at least one of the external or implantable resonant circuit is substantially more damped during the data time slots than during the power time slots.

30. The implantable medical device of claim 29, wherein the external and implantable resonant circuits are resonant tank circuits.

31. The implantable medical device of claim 29, wherein a resonance frequency of the external resonant circuit is adjusted during the data time slots so as to be lower or higher than the resonant frequency of the external resonant circuit during the power time slots.

32. The implantable medical device of claim 29, wherein a peak amplitude of current used to drive the external coil during the data time slots is lower than a peak amplitude of current used to drive the external coil during the power time slots.

33. The implantable medical device of claim 32, wherein the implantable coil is connected to an energy rectifier, and wherein the peak amplitude of current used to drive the external coil during the data time slot is such that the energy rectifier does not allow current to pass there through during the data time slots.

34. The implantable medical device of claim 29, wherein the first driver bridge is a half H-bridge and the second driver bridge is a full H-bridge.

35. An implantable medical device, comprising:

an implantable resonant circuit comprising an implantable coil; and

an external resonant circuit comprising an external coil configured to transcutaneously transfer power and data to the implantable coil using separate power time slots and data time slots, respectively,

a driver bridge, connected to the external resonant circuit, configured to drive the external coil during both the power and data time slots;

a first series circuit comprising a first resistor and a first inductor connected between a first output of the driver bridge and the external resonant circuit;

a second series circuit comprising a second resistor and a second inductor connected between a second output of the driver bridge and the external resonant circuit; and

a switch connected in parallel to the first and second series circuits between the first and second outputs of the driver bridge and the external resonant circuit,

wherein at least one of the external or implantable resonant circuit is substantially more damped during the data time slots than during the power time slots.