WIRELESS POWER MODULATION TELEMETRY FOR MEASURING A PARAMETER OF THE MUSCULAR-SKELETAL SYSTEM

• US 20100331735A1
• Filed: 06/29/2010
• Published: 12/30/2010
• Est. Priority Date: 06/30/2009
• Status: Abandoned Application

• Current Assignee: OrthoSensor, Inc (Stryker Corporation)
• Original Assignee: OrthoSensor, Inc (Stryker Corporation)
• Inventors: Stein, Marc
• Application Number:
  US12/825,671
• Publication Number:
  US 20100331735A1
• Time in Patent Office: Days
• US Class Current: 600/587
• 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 5/6846 specially adapted to be brought in contact with an internal body part, i.e. invasive
• CPC Class Codes: A61B 5/6878 Bone
• CPC Class Codes: A61B 5/7239 using differentiation including higher order derivatives
• CPC Class Codes: A61B 8/15 Transmission-tomography

Abstract

A sensing insert device (100) is disclosed for measuring a parameter of the muscular-skeletal system. The sensing insert device (100) can be temporary or permanent. Used intra-operatively, the sensing insert device (100) comprises an insert dock 202 and a sensing module 200. The sensing module (200) is a self-contained encapsulated measurement device having at least one contacting surface that couples to the muscular-skeletal system. The sensing module (200) comprises one or more sensors (303), electronic circuitry (307), a capacitor (1410), and communication circuitry (320). The electronic circuitry (307) operatively couples to the one or more sensors (303) to measure the parameter. A transmitter (309) transmits parameter measurements. The capacitor (1410) can store sufficient charge to power the sensing module (200) for a total joint reconstruction operation. Energy is wirelessly coupled to an induction coil (1404) thereby generating a power signal that provides charge to the capacitor (1410).

Claims

1. A system to measure a parameter of the muscular-skeletal system comprising:

a sensing module including;

one or more sensors for coupling to the muscular-skeletal system;

electronic circuitry operatively coupled to the sensors; and

a capacitor coupled to power the sensing module for a predetermined time.

2. The system of claim 1 where the capacitor is charge wirelessly.

3. The system of claim 2 where the sensing module further includes:

an induction coil;

a rectifier coupled to the induction coil; and

a regulator coupled to the rectifier to regulate a voltage output by the capacitor.

4. The system of claim 3 further including a wireless energy source placed in proximity to the sensing module where the wireless energy source electromagnetically couples to the induction coil and where a power signal is generated in the induction coil that charges the capacitor.

5. The system of claim 4 where the wireless energy source is placed within 20 centimeters of the sensing module.

6. The system of claim 4 where data is modulated on the power signal, where the data is demodulated from the power signal, and where the data is provided to the electronic circuitry.

7. The system of claim 1 where the sensing module is stored in a zero charge state prior to use.

8. The system of claim 7 where the capacitor is fully charged in less than 3 minutes from the zero charge state and where the capacitor has a solid dielectric.

9. The system of claim 8 where the sensing module is in a final insert to measure the parameter of the muscular-skeletal system where the final insert has at least one bearing surface for allowing movement of at least one bone of the muscular-skeletal system.

10. The system of claim 8 where the sensing module is used intra-operatively with a dock as a trial insert to measure the parameter of the muscular-skeletal system.

11. A method of enabling a sensing module for measuring a parameter of the muscular-skeletal system comprising the steps of:

placing a wireless energy source in proximity to the sensing module;

coupling electromagnetically to an induction coil in the sensing module;

generating a power signal in the induction coil comprising energy from the wireless energy source;

charging a capacitor with the power signal;

enabling the sensing module when the capacitor has stored sufficient charge to power the sensing module for a predetermined time; and

measuring at least one parameter of the muscular-skeletal system.

12. The method of claim 11 further including the steps of:

rectifying the power signal; and

regulating a voltage on the capacitor.

13. The method of claim 12 where the step of regulating further includes discharging the capacitor when the voltage on the capacitor exceeds a predetermined threshold.

14. The method of claim 13 further including the steps of:

demodulating input data from the power signal;

coupling the input data to operational circuitry of the sensing module; and

controlling at least one operation of the sensing module with the input data.

15. The method of claim 13 further including the steps of:

transmitting measured parameter measurements; and

discharging the capacitor after completion of the parameter measurements to disable the sensing module.

16. An insert device for coupling to the muscular-skeletal system comprising:

a surface on the insert device allowing articulation of the muscular-skeletal system; and

a sensing module including;

one or more sensors for coupling to the muscular-skeletal system;

electronic circuitry operatively coupled to the sensors; and

a capacitor coupled to power the sensing module for a predetermined time.

17. The insert device of claim 16, where the capacitor is charged wirelessly.

18. The insert device of claim 17 where the sensing module further includes:

an induction coil;

a rectifier coupled to the induction coil to rectify the signal;

a regulator coupled to the rectifier; and

the capacitor coupled to the regulator where the sensing module is enabled to measure a parameter of the muscular-skeletal after sufficient charge is stored on the capacitor to power the sensing module for a predetermined time.

19. The insert device of claim 18 further including a wireless energy source placed in proximity to the sensing module where the wireless energy source electromagnetically couples to the induction coil and where a power signal is generated in the induction coil that charges the capacitor.

20. The insert device of claim 19 where data is modulated on the power signal, where the data is demodulated from the power signal, and where the data is provided to the electronic circuitry.