Implantable sensor

• US 20070238992A1
• Filed: 02/01/2006
• Published: 10/11/2007
• Est. Priority Date: 02/01/2006
• Status: Abandoned Application

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: SDGI Holdings Incorporated (Medtronic Plc)
• Inventors: Cinbis, Can, Drapeau, Susan, Morrison, Matthew, Nycz, Jeffrey, Ye, Qingshan (Sam), Donofrio, William
• Application Number:
  US11/344,667
• Publication Number:
  US 20070238992A1
• Time in Patent Office: Days
• US Class Current: 600/437
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/4509 Bone density determination
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/6882 Anchoring means
• CPC Class Codes: A61B 7/005 Detecting noise caused by implants, e.g. cardiac valves
• CPC Class Codes: A61B 7/006 Detecting skeletal, cartilage or muscle noise A61B7/003 and A61B7/008 take precedence
• CPC Class Codes: A61B 8/0875 for diagnosis of bone A61B5/4504 takes precedence
• CPC Class Codes: A61B 8/4472 Wireless probes
• CPC Class Codes: A61B 8/56 Details of data transmission or power supply
• CPC Class Codes: A61B 8/565 involving data transmission via a network

Abstract

An implantable sensor for detecting changes in tissue density is disclosed. The implantable sensor includes a transducer adapted for detecting indicators of tissue density. The implantable sensor includes memory for storing data corresponding to the tissue density indicators detected by the sensor. A telemetry circuit is configured for transmitting the tissue density data outside of the body.

Claims

1. An implantable sensor for detecting indicators of the density of a tissue in a body, comprising:

a sensor having an external surface adapted to engage a portion of the body to maintain a position in the body, the sensor configured for detecting a signal indicative of a density of the tissue; and

a telemetry circuit in communication with the sensing element adapted for transmitting the detected signal outside of the tissue.

2. The implantable sensor of claim 1, wherein the sensing element is adapted for detecting acoustic signals.

3. The implantable sensor of claim 1, wherein the sensing element is adapted for detecting impedance signals.

4. The implantable sensor of claim 1, wherein the sensor is externally powered.

5. The implantable sensor of claim 4, wherein the telemetry circuit is adapted for transferring power from an external device to the sensing element.

6. The implantable sensor of claim 5, wherein the telemetry circuit includes a coil adapted for inductive coupling.

7. The implantable sensor of claim 1, wherein the portion of the body engaged by the external surface is the tissue.

8. The implantable sensor of claim 1, wherein the sensor is internally powered.

9. The implantable sensor of claim 1, wherein the tissue is a bone.

10. The implantable sensor of claim 9, wherein the sensor is adapted for detecting indicators of an osteolytic lesion.

11. The implantable sensor of claim 1, wherein the tissue is a soft tissue.

12. The implantable sensor of claim 1, wherein the portion of the body engaged by the external surface is a bone.

13. The implantable sensor of claim 1, wherein the portion of the body engaged by the external surface is a soft tissue.

14. The implantable sensor of claim 1, wherein the portion of the body engaged by the external surface is adjacent an artificial implant.

15. A system for detecting changes in tissue density, comprising:

an implantable acoustic sensor adapted for detecting a signal indicative of a density of a tissue and communicating the signal to an external receiver; and

an external receiver adapted for receiving the signal from the implantable sensor.

16. The system of claim 15, wherein the sensing element is adapted for detecting sounds.

17. The system of claim 15, wherein the sensing element is adapted for detecting vibrations.

18. The system of claim 15, wherein the implantable sensor is externally powered.

19. The system of claim 15, wherein the external receiver is adapted for providing power to the implantable sensor.

20. The system of claim 15, wherein the implantable sensor is internally powered.

21. The system of claim 20, wherein the implantable sensor includes a battery.

22. The system of claim 20, wherein the implantable sensor includes a memory unit adapted for storing tissue density data representative of the detected signals.

23. The system of claim 22, wherein the implantable sensor includes a signal processor.

24. The system of claim 23, wherein the tissue density is the density of a portion of a bone.

25. The system of claim 24, wherein the signal processor is adapted for classifying signals that are indicators of an osteolytic lesion.

26. The system of claim 25, wherein the memory unit is adapted for storing data corresponding to the osteolytic lesion indicators.

27. The system of claim 15, wherein the external receiver includes a signal processing unit adapted for creating tissue density data representative of the signals received from the implantable sensor.

28. The system of claim 27, wherein the external receiver includes a memory unit adapted for storing the tissue density data.

29. The system of claim 27, wherein the external receiver includes an output mechanism.

30. The system of claim 28, wherein the output mechanism is configured for outputting the tissue density data in a human intelligible form.

31. The system of claim 30, wherein the human intelligible form is a visual display.

32. The system of claim 29, wherein the output mechanism is configured for sending the tissue density data over a network.

33. The system of claim 15, wherein communication between the implantable sensor and the external receiver is wireless.

34. The system of claim 33, wherein the wireless communication is RFID communication.

35. The system of claim 15, further comprising a plurality of implantable acoustic sensors.

36. The system of claim 35, wherein the plurality of implantable acoustic sensors operate as redundancies.

37. The system of claim 35, wherein the plurality of implantable acoustic sensors operate together.

38. The system of claim 37, wherein the plurality of implantable acoustic sensors are adapted to locate a tissue density change based on the detected signals.

39. The system of claim 15, wherein the implantable sensor is adapted for percutaneous implantation.

40. The system of claim 39, wherein the implantable sensor is substantially cylindrical.

41. The system of claim 40, wherein the implantable sensor has a diameter less than 10 mm.

42. The system of claim 41, wherein the implantable sensor has a diameter less than 4 mm.

43. The system of claim 39, wherein the external receiver is implantable.

44. The system of claim 43, wherein the external receiver is adapted for percutaneous implantation.

45. A method of detecting a density of a tissue in a body, comprising:

providing a sensor adapted for detecting a signal indicative of a density of a tissue, the sensor having an external configuration adapted to engage a portion of the body to maintain a position in the body;

inserting the sensor into the body adjacent a site to be monitored;

engaging the external configuration with a portion of the body to maintain the position of the sensor; and

operating the sensor to detect a signal indicative of a density of the site.

46. The method of claim 45, wherein the sensor is an acoustic sensor.

47. The method of claim 45, wherein the sensor is an impedance sensor.

48. The method of claim 45, further comprising operating the sensor to detect a plurality of signals indicative of the density of the site.

49. The method of claim 48, further comprising analyzing the signals with respect to one another to detect changes in density.

50. The method of claim 49, wherein the analyzing includes comparison of a first audible signal with a second audible signal.

51. The method of claim 49, wherein the analyzing includes spectral analysis.

52. The method of claim 45, wherein the inserting includes percutaneously positioning the sensor.

53. The method of claim 52, wherein the inserting includes passing the sensor through a catheter.

54. The method of claim 45, wherein the site is an interface between an artificial implant and natural tissue.

55. The method of claim 54, further including implanting an artificial implant after inserting the sensor.

56. The method of claim 54, further including implanting an artificial implant prior to inserting the sensor.