Method and apparatus for measurement of transmitter/receiver separation

• US 20070100395A1
• Filed: 09/04/2003
• Published: 05/03/2007
• Est. Priority Date: 09/04/2002
• Status: Active Grant

• Current Assignee: Cochlear Limited
• Original Assignee: Cochlear Limited
• Inventors: Ibrahim, Ibrahim
• Granted Patent: US 8,452,412 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: H04R 25/554 using a wireless connection, e.g. between microphone and amplifier or using Tcoils

Abstract

A method and apparatus for determining a position of an external transceiver (24) relative to an implanted transceiver (23) comprising means (30) for measuring the strength of a magnetic field proximal to thc external transceiver (24) and means for determining a position of the external transceiver (24) relative to the implanted transceiver (23) from said measured magnetic field strength. Furthermore there is disclosed is a method and apparatus for determining a skin flap thickness of a recipient of a prosthesis including a transcutaneous link between the external transceiver (24) and the implanted transceiver (23). A skin-flap thickness meter is also provided.

Claims

1. A method of determining a position of an external transceiver relative to an implanted transceiver, the method comprising the steps of:

measuring the strength of a magnetic field proximal to the external transceiver; and

determining a position of the external transceiver relative to the implanted transceiver from said measured magnetic field strength.

2. The method according to claim 1 wherein the step of determining further comprises comparing a measured strength of magnetic field proximal to the external transceiver to a threshold value.

3. The method according to claim 2 further comprising the step of indicating that the external transceiver has been displaced when the measured strength of magnetic field proximal to the external transceiver exceeds the threshold value.

4. The method according to claim 3 wherein the step of indicating comprises providing an audible indication such as an alarm, a visible indication or other indication.

5. The method according to claim 1 wherein the step of determining further comprises mapping a measured value of magnetic field strength proximal to the external transceiver to a distance value.

6. The method according to claim 5 wherein the step of mapping comprises consulting a look-up table comprising a plurality of pairs of values, each pair of values mapping a particular magnetic field strength to a corresponding transceiver separation distance.

7. The method according to claim 5 wherein the step of mapping comprises algorithmically converting said measured value of magnetic field into a corresponding transceiver separation distance.

8. The method according to claim 1 further comprising the step of providing a transcutaneous link between the external transceiver and the implanted transceiver, the link being bidirectional such that the external transceiver and the implanted transceiver transmit and receive signals across the transcutaneous link.

9. The method according to claim 8 further comprising the step of transmitting power and data signals from the external transceiver to the implanted transceiver across the transcutaneous link.

10. The method according to claim 8 further comprising the step of transmitting data signals from the implanted transceiver to the external transceiver across the transcutaneous link.

11. The method according to claim 1 further comprising the step of providing a transcutaneous link between the external transceiver and the implanted transceiver, the link being unidirectional such that the external transceiver, comprising a transmitter, transmits signals to the implanted transceiver, comprising a receiver, across the transcutaneous link.

12. The method according to claim 11 wherein the signals transmitted by the transmitter are power and data signals.

13. The method according to claim 1 wherein the step of measuring comprises positioning a pick-up coil proximal to the external transceiver such that a voltage induced on the pick-up coil is indicative of a magnetic field proximal to the external transceiver.

14. The method according to claim 13 further comprising the step of positioning the pick-up coil in a plane substantially perpendicular to a primary axis of the magnetic field produced between the external receiver and the implanted receiver.

15. The method according to claim 14 wherein the pick-up coil comprises an open-circuited single turn positioned concentrically with turns of the external receiver.

16. An apparatus for determining a position of an external transceiver relative to an implanted transceiver, the apparatus comprising:

means for measuring the strength of a magnetic field proximal to the external transceiver; and

means for determining a position of the external transceiver relative to the implanted transceiver from said measured magnetic field strength.

17. The apparatus according to claim 16 further comprising means for comparing a measured strength of magnetic field proximal to the external transceiver to a threshold value.

18. The apparatus according to claim 17 further comprising means for indicating that the external transceiver has been displaced when the measured strength of magnetic field proximal to the external transceiver exceeds the threshold value.

19. The apparatus according to claim 18 wherein the means for indicating comprises any one of an audible alarm, a visible indicator or other type of indicator.

20. The apparatus according to claim 16 further comprising means for mapping a measured value of magnetic field strength proximal to the external transceiver to a distance value.

21. The apparatus according to claim 20 wherein the means for mapping comprises a look-up table comprising a plurality of pairs of values of magnetic field strength to transceiver separation distance.

22. The apparatus according to claim 20 wherein the means for mapping comprises means for algorithmically converting said measured value of magnetic field into a corresponding transceiver separation distance.

23. The apparatus according to claim 16 further comprising a transcutaneous link provided by the external transceiver and the implanted transceiver.

24. The apparatus according to claim 23 wherein the transcutaneous link comprises an RF link.

25. The apparatus according to claim 23 wherein the transcutaneous link is bidirectional such that the external transceiver and the implanted transceiver transmit and receive signals across the transcutaneous link.

26. The apparatus according to claim 25 wherein power and data signals are transmitted from the external transceiver to the implanted transceiver across the transcutaneous link.

27. The apparatus according to claim 25 wherein data signals are transmitted from the implanted transceiver to the external transceiver across the transcutaneous link.

28. The apparatus according to claim 23 wherein the transcutaneous link is unidirectional, the external transceiver comprises a transmitter and the implanted transceiver comprises a receiver, such that the transmitter transmits signals to the receiver across the transcutaneous link.

29. The apparatus according to claim 28 wherein the signals transmitted by the transmitter are power and data signals.

30. The apparatus according to claim 16 wherein the means for measuring the strength of the magnetic field proximal to the external transceiver comprises a pickup coil positioned proximal to the external transceiver, such that a voltage induced on the pickup coil is indicative of a magnetic field proximal to the external transceiver.

31. The apparatus according to claim 30 wherein the pickup coil is positioned in a plane substantially perpendicular to a primary axis of the magnetic field produced by the transceivers.

32. The apparatus according to claim 31 wherein the pickup coil comprises an open circuited single turn positioned concentrically with turns of the external transceiver.

33. The apparatus according to claim 30 wherein an output of the pick-up coil is passed through a peak detector means.

34-57. -57. (canceled)

58. An apparatus for determining a position of an external transceiver relative to an implanted transceiver, the apparatus comprising:

means for measuring the strength of a magnetic field proximal to the external transceiver;

means for determining a position of the external transceiver relative to the implanted transceiver from said measured magnetic field strength;

means for comparing a measured strength of magnetic field proximal to the external transceiver to a threshold value;

means for indicating that the external transceiver has been displaced when the measured strength of magnetic field proximal to the external transceiver exceeds the threshold value; and

means for mapping comprises a look-up table comprising a plurality of pairs of values of magnetic field strength to transceiver separation distance.

59. (canceled)