System and method for bidirectional communication with an implantable medical device using an implant component as an antenna

• US 20060009856A1
• Filed: 06/29/2004
• Published: 01/12/2006
• Est. Priority Date: 06/29/2004
• Status: Active Grant

• Current Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Inventors: DiSilvestro, Mark R., Sherman, Jason T.
• Granted Patent: US 8,176,922 B2
• Time in Patent Office: Days
• US Class Current: 623/20.320
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2002/3067 for data transfer
• CPC Class Codes: A61F 2250/0002 for data transfer

Abstract

A system and method enables data to be communicated from a position within a human body to an external data device. The system includes a wireless communication module that is electrically coupled to an implant component having a metal surface so that the implant component operates as an antenna in response to the application of a modulated carrier wave being applied to the implant component. The wireless communication module may be coupled to the implant component so that the implant component operates as a monopole or dipole antenna. When the monopole configuration is used, the system further includes a ground plane so that the electromagnetic field emitted by the implant component is reflected and the emitted and reflected fields resemble the emitted field of a dipole antenna for the carrier frequency.

Claims

1. A data communication system for wirelessly communicating data from within a human body to a data communication device external to the body, comprising:

an implant component having a metal surface; and

a wireless communication module electrically coupled to the implant component so that a length of the implant component operates as an antenna.

2. The system of claim 1 wherein the wireless communication module is a module for sending a signal modulated with sensor data through the implant component.

3. The system of claim 1 wherein the wireless communication module is a module for receiving a data signal through the implant component.

4. The system of claim 1 wherein the wireless communication module is a transceiver for both transmitting and receiving signals through the implant component.

5. The system of claim 1 wherein the wireless communication module is coupled to the implant component at a point where the length of the implant component that operates as an antenna is an integral number of half-wavelengths for a carrier wave used for communication through the antenna.

6. The system of claim 5 wherein the wireless communication module is coupled to the implant component at approximately its midpoint so that the implant component operates as a dipole antenna.

7. The system of claim 5 wherein the wireless communication module is coupled to the implant component at one end of the implant component so that the implant component operates as a dipole antenna, and the system further comprising:

a ground plane positioned to reflect the emitted field from the implant component so that reflected and emitted field of the implant component resembles the emitted field from a dipole antenna having a length approximately one half-wavelength of the carrier signal.

8. The system of claim 7 wherein the ground plane is incorporated in the implant component operating as an antenna.

9. The system of claim 7 wherein the ground plane is incorporated in another implant component used to reconstruct the joint in which the implant component operating as an antenna is located.

10. The system of claim 1 wherein the wireless communication module communicates data on a carrier wave frequency of about 2.4 GHz.

11. A data communication system for wirelessly communicating data from a reconstructed knee comprising:

a tibial component having a metal surface;

a wireless communication module coupled to the tibial component; and

a sensor located proximate to the tibial component to sense a parameter near the tibial component, the sensor being coupled by a wire to the wireless communication module so that a signal generated by the sensor is provided over the wire to the wireless communication module and the wireless communication module uses the signal received from the sensor to modulate a carrier frequency that is applied to the tibial component for radiation to an external data device.

12. The system of claim 11 wherein the tibial component is coupled to the wireless communication module so that the tibial component operates as a dipole antenna.

13. The system of claim 11 wherein the tibial component is coupled to the wireless communication module so that the tibial component operates as a monopole antenna;

and the system further includes;

a ground plane to reflect the electromagnetic field emitted by the tibial component so the emitted and reflected field of the monopole antenna resembles a field produced by a dipole antenna for the carrier frequency.

14. A method for wirelessly communicating data from within a human body to a device external to the human body, comprising:

electrically coupling a wireless communication module to an implant component having a metal surface; and

operating the implant component as an antenna for wireless communication between the wireless communication module and a data communication device external to a patient in which the implant component is implanted.

15. The method of claim 14 further comprising:

transmitting a modulated carrier wave through the implant component operating as an antenna

16. The method of claim 14 further comprising:

receiving a modulated carrier wave through the implant component operating as an antenna.

17. The method of claim 14 further comprising:

modulating a carrier wave transmitted through the implant component with sensor data.

18. The method of claim 14 further comprising:

demodulating a modulated carrier wave received through the implant component to obtain a data signal from an external data communication device.

19. The method of claim 14 wherein the coupling of the wireless communication module to the implant component occurs at a point where the length of the implant component that operates as an antenna is an integral number of half-wavelengths of the carrier wave.

20. The method of claim 14 wherein the coupling of the wireless communication module to the implant component occurs at a point that enables the implant component to operate as a dipole antenna for a carrier wave frequency.

21. The method of claim 14 wherein the coupling of the wireless communication module to the implant component occurs at a point that enables the implant component to operate as a monopole antenna;

and the method also includes;

positioning a ground plane to reflect the electromagnetic field emitted by the implant component so that the reflected and emitted field of the monopole antenna corresponds to one generated by a dipole antenna.

22. The method of claim 21 further comprising:

incorporating the ground plane in the implant component operating as an antenna.

23. The method of claim 21 further comprising:

incorporating the ground plane in an implant component used to reconstruct the joint other than the implant component being operated as an antenna.

24. The method of claim 14 further comprising:

variably tuning the external data communication device until a response signal is received from the wireless communication module through the implant component acting as an antenna; and

determining the length of the implant component operating as an antenna from the frequency of the response signal.

25. A method for wirelessly communicating data from a reconstructed knee, comprising:

electrically coupling a wireless communication module to a tibial component for wireless communication with an external data communication device;

coupling a sensor to the wireless communication module;

modulating a carrier frequency with data received from the sensor coupled to the wireless communication module; and

radiating the modulated carrier frequency through the tibial component.

26. The method of claim 25 further comprising:

demodulating the modulated carrier frequency to obtain the data used to modulate the carrier frequency.

27. The method of claim 25 wherein the tibial component is coupled to the wireless communication module so that the tibial component operates as a monopole antenna;

and the method further includes;

positioning a ground plane to reflect the electromagnetic field emitted by the tibial component operating as a monopole antenna so that the emitted field and reflected field corresponds to that produced by a dipole antenna for the carrier frequency.

28. The method of claim 27 wherein the ground plane is positioned within a polyethylene insert on the tibial component to reflect the electromagnetic field emitted by the tibial component.

29. The method of claim 25 further comprising:

variably tuning an external data communication device so the wireless communication module provides a response signal to the external device through the implant component; and

determining the length of the tibial component from the frequency on which the response signal was received.