Transcutaneous capacitive data link

1. An implantable medical device, comprising:

a transcutaneous capacitive data link circuit comprising:

a first pair of capacitors each having an external electrode configured to be externally positioned on a recipient and an internal electrode configured to be internally positioned in the recipient;

a first voltage driver having positive and negative terminals each connected to one of the external electrodes, and configured to generate a first voltage drive signal responsive to a first input control signal; and

a first differential amplifier circuit connected to the internal electrodes, configured to generate a first output data signal representative of the first input control signal.

2. The implantable medical device of claim 1 , wherein the data link circuit further comprises:

a second pair of capacitors each having an external electrode configured to be externally positioned on a recipient and an internal electrode configured to be internally positioned in the recipient;

a second voltage driver having positive and negative terminals each connected to one of the internal electrodes of the second pair of capacitors, and configured to generate a second voltage drive signal responsive to a second input control signal; and

a second differential amplifier circuit connected to the external electrodes of the second pair of capacitors, configured to generate a second output data signal representative of the second input control signal.

3. The implantable medical device of claim 2 , wherein:

the second input control signal comprises telemetry signals generated by an implanted stimulator unit of the implantable medical device; and

the second output data signal is suitable for receipt by a speech processor unit of the implantable medical device.

4. The circuit of claim 2 , wherein the second differential amplifier circuit comprises:

a differential amplifier; and

a resistive network connected between the differential amplifier and the internal electrodes.

5. The implantable medical device of claim 1 , wherein:

the first input control signal comprises a coded sound signal generated by a speech processor unit of an implantable medical device, and

the first output control signal is suitable for receipt by an implanted stimulator unit of the implantable medical device.

6. The implantable medical device of claim 1 , wherein the first differential amplifier circuit comprises:

a differential amplifier; and

a resistive network connected between the differential amplifier and the internal electrodes.

7. The implantable medical device of claim 1 , wherein:

each capacitor of the first pair thereof includes opposing electrodes;

each electrode is substantially planar and has an axis substantially orthogonal thereto; and

for each capacitor, the axes of opposing electrodes thereof are substantially aligned with each other.

8. The implantable medical device of claim 1 , wherein:

the implantable medical device is an implantable auditory prosthesis.

9. The implantable medical device of claim 8 , wherein:

the implantable auditory prosthesis is a cochlear implant.

10. An implantable medical device, comprising:

a transcutaneous capacitive data link circuit comprising:

a first pair of capacitors each having an external electrode configured to be externally positioned on a recipient and an internal electrode configured to be internally positioned in the recipient;

first voltage driver means, having positive and negative terminals each connected to one of the external electrodes, for generating a first voltage drive signal responsive to a first input control signal; and

first differential amplifier means connected to the internal electrodes, for generating a first output data signal representative of the first input control signal.

11. The implantable medical device of claim 10 , wherein the data link circuit further comprises:

a second pair of capacitors each having an external electrode configured to be externally positioned on a recipient and an internal electrode configured to be internally positioned in the recipient;

second voltage driver means having positive and negative terminals each connected to one of the internal electrodes of the second pair of capacitors, for generating a second voltage drive signal responsive to a second input control signal; and

second differential amplifier means connected to the external electrodes of the second pair of capacitors, for generating a second output data signal representative of the second input control signal.

12. The implantable medical device of claim 11 , wherein:

the second input control signal comprises telemetry signals generated by an implanted stimulator unit of an implantable medical device, and

the second output data signal is suitable for receipt by a speech processor unit of the implantable medical device.

13. The implantable medical device of claim 10 , wherein:

the first input control signal comprises a coded sound signal generated by a speech processor unit of an implantable medical device, and

the first output control signal is suitable for receipt by an implanted stimulator unit of the implantable medical device.

14. A transcutaneous capacitive data link circuit comprising:

a first pair of capacitors each having an external electrode configured to be externally positioned on a recipient and an internal electrode configured to be internally positioned in the recipient;

a first voltage driver having positive and negative terminals each connected to one of the external electrodes, and configured to generate a first voltage drive signal responsive to a first input control signal; and

a first differential amplifier circuit connected to the internal electrodes, configured to generate a first output data signal representative of the first input control signal.

15. The circuit of claim 14 , further comprising:

a second pair of capacitors each having an external electrode configured to be externally positioned on a recipient and an internal electrode configured to be internally positioned in the recipient;

a second voltage driver having positive and negative terminals each connected to one of the internal electrodes of the second pair of capacitors, and configured to generate a second voltage drive signal responsive to a second input control signal; and

a second differential amplifier circuit connected to the external electrodes of the second pair of capacitors, configured to generate a second output data signal representative of the second input control signal.

16. The circuit of claim 15 , wherein:

the second input control signal comprises telemetry signals generated by an implanted stimulator unit of a cochlear implant; and

the second output data signal is suitable for receipt by a speech processor unit of the cochlear implant.

17. The circuit of claim 15 , wherein the second differential amplifier circuit comprises:

a differential amplifier; and

a resistive network connected between the differential amplifier and the internal electrodes.

18. The circuit of claim 14 , wherein:

the first input control signal comprises a coded sound signal generated by a speech processor unit of a cochlear implant; and

the first output control signal is suitable for receipt by an implanted stimulator unit of the cochlear implant.

19. The circuit of claim 14 , wherein the first differential amplifier circuit comprises:

a differential amplifier; and

a resistive network connected between the differential amplifier and the internal electrodes.

20. The circuit of claim 14 , wherein:

each capacitor of the first pair thereof includes opposing electrodes;

each electrode is substantially planar and has an axis substantially orthogonal thereto; and

for each capacitor, the axes of opposing electrodes thereof are substantially aligned with each other.