In vivo joint implant cycle counter

• US 20050010299A1
• Filed: 07/09/2004
• Published: 01/13/2005
• Est. Priority Date: 07/11/2003
• Status: Active Grant

• Current Assignee: Depuy Synthes Products Incorporated (Johnson & Johnson)
• Original Assignee: Depuy Products Incorporated (Johnson & Johnson)
• Inventors: Disilvestro, Mark R.
• Granted Patent: US 7,347,874 B2
• Time in Patent Office: Days
• US Class Current: 623/18.120
• CPC Class Codes: A61B 2090/0803 Counting the number of times an instrument is used
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• 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 5/1038 Measuring plantar pressure during gait
• CPC Class Codes: A61B 5/1076 for measuring dimensions inside body cavities, e.g. using catheters A61B3/1005 takes precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• 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 2/367 Proximal or metaphyseal parts of shafts trochanteric devices connected to said proximal parts A61F2/30739
• CPC Class Codes: A61F 2/38 for elbows or knees
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2/389 Tibial components A61F2/3868 takes precedence
• CPC Class Codes: A61F 2/40 for shoulders
• CPC Class Codes: A61F 2/4081 Glenoid components, e.g. cups
• CPC Class Codes: A61F 2/468 Testing instruments for artificial joints for testing non-implantable prostheses A61F2/76
• CPC Class Codes: A61F 2/488 Means for detecting or monitoring wear
• CPC Class Codes: A61F 2002/30326 differing in height or in length
• CPC Class Codes: A61F 2002/3067 for data transfer
• CPC Class Codes: A61F 2002/30892 parallel
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/4018 : Heads or epiphyseal parts of humerus
• CPC Class Codes: A61F 2002/4062 : Proximal or metaphyseal parts of shafts
• CPC Class Codes: A61F 2002/4698 : magnetic
• CPC Class Codes: A61F 2250/0002 : for data transfer
• CPC Class Codes: A61F 2250/0037 : differing in height or in length
• CPC Class Codes: Y10S 623/914 : Bone

Abstract

A joint endoprosthesis system has two prosthetic components to be affixed to two bones of a human joint. A sensor and electronic components are affixed to one of the prosthetic components so that a record can be maintained of the number of times the patient moves the prosthetic joint in a particular way, such as in walking. This information is stored within the electronic components and selectively transmitted to an external system for interpretation of the data. The caregiver can use this data to counsel the patient on life-style changes or to prescribe therapeutic treatments if available.

Claims

1. A joint endoprosthesis system to be implanted in a patient, the system comprising:

a first prosthetic component to be affixed to one bone of the joint;

a second prosthetic component to be affixed to the other bone of the joint;

a sensor for generating a signal each time the bones of the joint are in a predetermined condition;

a counter for storing the number of signals generated by the sensor.

2. The joint endoprosthesis system of claim 1 wherein the predetermined condition for generating a signal comprises a predetermined level of load at the joint.

3. The joint endoprosthesis of claim 2 wherein the sensor comprises a load sensor.

4. The joint endoprosthesis system of claim 1 wherein the predetermined condition for generating a signal comprises an angle between at least one of the bones of the joint and a reference.

5. The joint endoprosthesis system of claim 4 wherein the sensor comprises a proximity sensor.

6. The joint endoprosthesis system of claim 4 wherein the sensor comprises a transducer.

7. The joint endoprosthesis system of claim 4 wherein the sensor comprises a transponder.

8. The joint endoprosthesis system of claim 4 wherein the sensor comprises a switch.

9. The joint endoprosthesis system of claim 1 wherein the predetermined condition for generating a signal is associated with one of the following patient actions:

walking;

sitting;

running;

squatting and lifting.

10. The joint endoprosthesis system of claim 1 further comprising a signal source affixed to the first prosthetic component and wherein the sensor is affixed to the second prosthetic component.

11. The joint endoprosthesis system of claim 10 wherein the signal source is capable of generating an electromagnetic or magnetostatic field.

12. The joint endoprosthesis system of claim 10 wherein the signal source is capable of generating a radio-frequency wave.

13. The joint endoprosthesis system of claim 10 wherein the signal source is capable of generating an eddy current.

14. The joint endoprosthesis system of claim 1 further comprising a first power source for supplying continuous power to the counter.

15. The joint endoprosthesis system of claim 1 further comprising a transmitter for transmitting data related to the number of signals stored.

16. The joint endoprosthesis system of claim 15 further comprising:

a first power source for supplying continuous power to the counter; and

a second power source for selectively supplying power to the transmitter.

17. A joint endoprosthesis system comprising:

a first prosthetic component to be affixed to one bone of the joint;

a second prosthetic component to be affixed to the other bone of the joint;

a sensor for generating a signal each time the bones are in a predetermined position;

a counter for storing the incremental number of signals generated by the sensor;

a transmitter for selectively transmitting a signal having a characteristic related to the incremental count recorded by the counter;

a first power source for supplying continuous power to the counter; and

a second power source for selectively supplying power to the transmitter.

18. The joint endoprosthesis system of claim 17 wherein the sensor comprises a switch.

19. The joint endoprosthesis of claim 18 wherein the transducer comprises a Hall effect switch, the joint endoprosthesis further comprising a permanent magnet.

20. The joint endoprosthesis system of claim 19 wherein the switch is associated with one of the bones of the joint and the permanent magnet is associated with the other bone of the joint.

21. The joint endoprosthesis of claim 19 wherein at least one of the switch and the magnet is affixed to one of the prosthetic components.

22. The joint endoprosthesis of claim 21 wherein the switch is affixed to the first prosthetic component and the permanent magnet is affixed to the other prosthetic component.

23. The joint endoprosthesis of claim 17 wherein the first prosthetic component comprises a distal femoral component and the second prosthetic component comprises a proximal tibial component.

24. The joint endoprosthesis of claim 17 wherein the first prosthetic component comprises a proximal femoral component and the second prosthetic component comprises an acetabular cup.

25. The joint endoprosthesis of claim 17 wherein the first prosthetic component comprises a humeral component and the second prosthetic component comprises a glenoid component.

26. The joint endoprosthesis system of claim 17 further comprising a signal source affixed to the first prosthetic component and wherein the sensor and transmitter are affixed to the second prosthetic component.

27. The joint endoprosthesis system of claim 26 wherein the signal source is capable of generating an electromagnetic or magnetostatic field.

28. The joint endoprosthesis system of claim 26 wherein the signal source is capable of generating a radio-frequency wave.

29. The joint endoprosthesis system of claim 26 wherein the signal source is capable of generating an eddy current.

30. The joint endoprosthesis system of claim 17 wherein the first power source and the second power source are affixed to the second prosthetic component.

31. A method of monitoring use of an implanted joint endoprosthesis system, wherein the joint endoprosthesis system includes a first prosthetic component affixed to one bone of the joint and a second prosthetic component affixed to another bone of the joint, wherein the first and second prosthetic components are movable through a plurality of positions, the method comprising the steps of:

generating a signal each time the first and second prosthetic components are in a predetermined position;

storing an incremental count of the number of signals generated within the patient'"'"'s body;

converting the incremental count stored into a transmittable signal;

transmitting the transmittable signal to a position outside of the patient'"'"'s body; and

determining the incremental count outside of the patient'"'"'s body.