Implantable pedometer

• US 7,328,131 B2
• Filed: 02/01/2006
• Issued: 02/05/2008
• Est. Priority Date: 02/01/2006
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc), Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Schugt, Michael A., Donofrio, William T., Nycz, Jeffrey H., Cinbis, Can, Hill, Gerard J., Audet, Sarah Anne, Ye, Qingshan (Sam)
• Primary Examiner(s): Cosimano; Edward R
• Application Number:
  US11/344,999
• Publication Number:
  US 20070179739A1
• Time in Patent Office: 734 Days
• Field of Search: 734/321, 735/70, 735/77, 735/84, 735/87, 736/45, 736/46, 737/60, 737/63, 737/64, 737/68, 737/74, 737/75, 738/651, 340/500, 340/531, 340/539.1, 340/539.11, 340/539.12, 340/573.1, 340/669, 340/870.01, 340/870.07, 377/1, 377/13, 377/15, 377/16, 702/33, 702/34, 702/41, 702/42, 702/127, 702/141, 702/160, 702/182, 702/183, 600/552, 600/553, 600/586, 600/587
• US Class Current: 702/183
• CPC Class Codes: A61B 17/86 Pins or screws or threaded wires; nuts therefor A61B17/72 take precedence
• CPC Class Codes: A61B 2562/0219 Inertial sensors, e.g. accelerometers, gyroscopes, tilt switches
• CPC Class Codes: A61B 5/1118 Determining activity level
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/686 Permanently implanted devices, e.g. pacemakers, other stimulators, biochips A61B5/6861 takes precedence
• CPC Class Codes: A61F 2/2803 for mandibular reconstruction temporo-mandibular joints A61F2/3099; bone plates for the jaw A61B17/8071
• CPC Class Codes: A61F 2/32 for the hip
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/36 Femoral heads ; Femoral endoprostheses
• CPC Class Codes: A61F 2/3676 Distal or diaphyseal parts of shafts
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3804 for elbows
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/4202 for ankles
• CPC Class Codes: A61F 2/4261 for wrists
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2/488 Means for detecting or monitoring wear
• CPC Class Codes: A61F 2002/30448 : using adhesives
• CPC Class Codes: A61F 2002/3067 : for data transfer
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/3403 : Polar aperture
• CPC Class Codes: A61F 2002/3429 : with an integral peripheral collar or flange, e.g. oriented away from the shell centre line
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3625 : Necks
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/4666 : for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2220/005 : using adhesives
• CPC Class Codes: A61F 2250/0002 : for data transfer

Abstract

An implantable pedometer for measuring the amount of joint use is disclosed. The implantable pedometer includes a sensor adapted for detecting indicators of joint usage. A counter is configured for storing count data corresponding to the number of indicators detected by the sensor and a telemetry circuit is configured for transmitting the count data outside of the body.

Claims

1. An implantable pedometer for measuring use of a joint in a skeletal system, comprising:

an elongated housing having an external surface, at least a portion of the external surface configured for bone engagement;

an acoustic sensor disposed within the housing, the sensor adapted for detecting a sound indicative of joint use;

a memory unit disposed within the cylindrical housing and in communication with the sensor, the memory unit adapted for storing a count data corresponding to the number of sounds indicative of joint use detected; and

a telemetry circuit configured for transmitting the count data outside of the skeletal system.

2. The pedometer of claim 1, wherein the sensor is adapted for engaging a bone of the joint.

3. The pedometer of claim 1, wherein the external surface includes a fixation projection.

4. The pedometer of claim 3, wherein the fixation projection includes bone screw threads.

5. The pedometer of claim 1, wherein the joint is an artificial joint.

6. The pedometer of claim 5, wherein the sensor is adapted for being disposed adjacent to the artificial joint.

7. The pedometer of claim 5, wherein the sensor is adapted for being disposed distal to the artificial joint.

8. The pedometer of claim 5, wherein the artificial joint is one of the following an ankle, a knee, a hip, a spinal portion, a shoulder, an elbow, a wrist, or a jaw.

9. The pedometer of claim 5, wherein the external surface includes a means for attaching to the artificial joint.

10. The pedometer of claim 9, wherein the means for attaching to the artificial joint is a threaded connection.

11. An implantable pedometer for measuring use of a joint in a skeletal system, comprising:

an acoustic sensor adapted for detecting an indicator of joint use

a counter for storing a count data corresponding to the number of indicators detected;

a telemetry circuit configured for transmitting the count data outside of the skeletal system; and

an elongated housing for holding the acoustic sensor, the counter, and the telemetry circuit.

12. The pedometer of claim 11, wherein the acoustic sensor includes a piezoelectric transducer.

13. The pedometer of claim 11, wherein the joint is one of a spinal portion, a shoulder, an elbow, a wrist, or a jaw.

14. The pedometer of claim 11, wherein the acoustic sensor includes a microphone.

15. The pedometer of claim 14, wherein the pedometer further includes a recording device in communication with the microphone.

16. The pedometer of claim 15, wherein the recording device operates using a buffer.

17. The pedometer of claim 11, wherein the joint is one of a hip, a knee, or an ankle.

18. The pedometer of claim 17, wherein the indicator is a sound.

19. The pedometer of claim 18, wherein the sound is associated with stepping.

20. An implantable pedometer for measuring use of a joint in a skeletal system, comprising:

a single elongated pedometer housing adapted for containing all components of the pedometer;

a sensor disposed within the pedometer housing, the sensor adapted for detecting indicators of joint use and storing a count data corresponding to the number of indicators detected; and

a telemetry circuit disposed within the housing, the telemetry circuit configured for transmitting the count data outside of the skeletal system.

21. A method of using an implantable pedometer to evaluate use of a joint in a body, comprising:

implanting a programmable sensor into the body, the sensor adapted for detecting indicators associated with use of the joint, storing a usage data corresponding to the number of indicators detected that satisfy a threshold, and modifying the threshold based on an external input;

obtaining the usage data from the sensor; and

analyzing the usage data to evaluate the amount of use of the joint.

22. The method of claim 21, further comprising modifying the threshold based on an external input.

23. The method of claim 22, wherein the indicators correlate to movements related to use of the joint.

24. The method of claim 23, wherein the usage data is a representation of the number of movements made.

25. The method of claim 23, further comprising analyzing the usage data by spectral analysis.

26. The method of claim 23, wherein the sensor is further adapted for distinguishing between different types of movements.

27. The method of claim 26, wherein the usage data is grouped by the different types of movements.

28. The method of claim 22, wherein the joint is an artificial joint.

29. The method of claim 28, wherein the sensor is implanted during the same surgical procedure as the artificial joint.

30. The method of claim 29, wherein the sensor is attached to a portion of the artificial joint prior to being implanted.

31. The method of claim 28, wherein the sensor is implanted in a surgical procedure separate from the surgical procedure used to implant the artificial joint.

32. The method of claim 31, wherein the sensor is implanted percutaneously.

33. An implantable pedometer for measuring use of an artificial hip implant within a patient, the pedometer comprising:

an elongated housing adapted for implantation through a catheter and separate from the artificial hip implant, the housing having an external surface configured for tissue engagement;

an acoustic sensor disposed within the housing, the acoustic sensor configured for detecting an acoustic indicator of the patient taking a step;

a memory unit disposed within the housing and in communication with the acoustic sensor, the memory unit for storing a count data corresponding to the number of indicators detected; and

a telemetry circuit configured for transmitting the count data outside of the skeletal system.

34. The pedometer of claim 33, further comprising a power source disposed within the housing and connected to the acoustic sensor and the memory unit.

35. The pedometer of claim 34, wherein the power source is a rechargeable battery.

36. The pedometer of claim 34, wherein the power source is rechargeable wirelessly.

37. The pedometer of claim 34, further comprising a signal processor disposed within the housing and in communication with the acoustic sensor and the memory unit, the signal processor for determining whether a detected acoustic signal is an indicator of the patient taking a step.

38. The pedometer of claim 37, wherein the telemetry circuit includes an antenna.

39. The pedometer of claim 37, wherein the telemetry circuit includes a coil adapted for inductive coupling.

40. The pedometer of claim 37, wherein the count data stored by the memory unit is a scaled representation of the number of indicators detected.

41. The pedometer of claim 40, wherein the memory unit is adapted to be reset to clear the count data.

42. The pedometer of claim 37, wherein the external surface is configured for being disposed in a bony tissue adjacent to the artificial hip implant.

43. The pedometer of claim 42, wherein the external surface includes a anti-migration structure to provide a secure engagement between the housing and the bony tissue.

44. The pedometer of claim 37, wherein the external surface is configured for being disposed in a soft tissue adjacent to the artificial hip implant.

45. The pedometer of claim 44, wherein the wherein the external surface includes a anti-migration structure to prevent unwanted movement between the housing and the soft tissue.

46. The pedometer of claim 37, wherein the signal processor determines whether the detected acoustic signal satisfies a predetermined parameter indicative of the patient taking a step.

47. The pedometer of claim 46, wherein the predetermined parameter is selected from the group consisting of an amplitude range, a frequency range, and a decibel range.

48. The pedometer of claim 46, wherein the signal processor is programmable to set the predetermined parameter.

49. The pedometer of claim 48, wherein the signal processor is programmable wirelessly.