HIGH PRECISION PROCESSING OF MEASUREMENT DATA FOR THE MUSCULAR-SKELETAL SYSTEM

• US 20100331680A1
• 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:
  US12/825,898
• Publication Number:
  US 20100331680A1
• Time in Patent Office: Days
• US Class Current: 600/437
• 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 measurement system measures a parameter of a muscular-skeletal system. The measurement system is placed in proximity to the muscular-skeletal system such that the parameter to be measured is applied to a sensing assemblage (3). The measurement system further comprises a digital counter (20), a digital timer (22), a digital clock 24, and a data register (26). The digital counter (20) is preset to a predetermined number of measurement cycles. The digital timer (22) measures an elapsed time of a measurement sequence comprising the predetermined number of measurement cycles. The digital counter (20) is decremented each measurement cycle until a zero count is reached thereby stopping the measurement sequence. The digital timer (22) measures an elapsed time of the measurement sequence. The parameter value can be related to the elapsed time. The precision of a parameter measurement can be modified by changing the predetermined number of measurement cycles.

Claims

1. A high precision method to measure a parameter corresponding to the muscular-skeletal system comprising the steps of:

presetting a measurement sequence for a predetermined number of measurement cycles;

generating a sum corresponding to the measurement sequence; and

measuring an elapsed time of the measurement sequence.

2. The method of claim 1 further including a step of increasing the predetermined number of measurement cycles to raise measurement precision.

3. The method of claim 1 further including a step of dividing the sum corresponding to the measurement sequence by the elapsed time.

4. The method of claim 3 further including the steps of:

applying the parameter to a medium during the measurement sequence;

emitting an energy wave into the medium;

detecting a propagated energy wave;

counting each detected propagated energy wave; and

stopping the measurement sequence when a count of detected propagated energy waves equals the predetermined number of measurement cycles.

5. The method of claim 4 further including a step of emitting an energy wave into the medium upon detection of each propagated energy wave to sustain energy wave propagation during the measurement sequence.

6. The method of claim 5 further including a step of maintaining an integer number of energy waves in the medium during the measurement sequence.

7. The method of claim 5 further including a step of relating a transit time, frequency, or phase measured during the measurement sequence to generate a parameter measurement.

8. The method of claim 1 further including the steps of:

setting a counter to the predetermined number of measurement cycles;

decrementing the counter upon detection of each propagated energy wave; and

stopping the measurement sequence when the counter decrements to zero.

9. The method of claim 8 further including the steps of:

dividing the predetermined number of measurement cycles by the elapsed time; and

storing a result in a data register.

10. The method of claim 9 further including the steps of:

placing a sensing module in proximity to the muscular-skeletal system such that the parameter to be measured is applied directly or indirectly to the sensing module; and

controlling an operation of the sensing module wirelessly to achieve a specific resolution of measurement data;

control processes that include adjusting an ultrasonic frequency, a sampling frequency, a waveguide length, a data rate, and bandwidth in real-time.

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

placing a sensing assemblage in proximity to the muscular-skeletal system;

setting a precision level and resolution of captured data to optimize a trade-off between measurement resolution versus ultrasonic frequency prior to a measurement sequence; and

adjusting a bandwidth of a transceiver providing data communications to deliver the captured data in real-time.

12. The method of claim 11, further including a step of optimizing the tradeoff by evaluating measurement resolution versus a length of a waveguide propagation medium;

13. The method of claim 11 further including a step of optimizing the tradeoff by adjusting the frequency of the ultrasonic energy waves or repetition rate or energy pulses;

14. The method of claim 11 further including a step of optimizing the tradeoff by adjusting a bandwidth of sensing and data capture operations.

15. The method of claim 11, comprising accumulating multiple cycles of excitation and transit time of ultrasonic energy waves.

16. The method of claim 11, comprising controlling a digital counter to run through multiple measurement cycles, each cycle having excitation and transit phases such that there is not lag between successive measurement cycles, and capturing a total elapsed time.

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

a sensor placed in proximity to the muscular-skeletal system;

a digital counter coupled to a sensor where a signal corresponding to a measurement cycle of the sensor clocks the digital counter;

a digital timer to measure an elapsed time of a measurement sequence where the measurement sequence comprises a predetermined number of measurement cycles;

a data register coupled to the digital timer to store a number calculated from the predetermined number of measurement cycles and the elapsed time of the measurement sequence.

18. The measurement system of claim 17 where the precision of a parameter measurement increases by increasing the predetermined number of measurement cycles.

19. The measurement system of claim 18 further including a clock operatively coupled to the digital counter and the digital timer where a parameter value relates to a time period of a measurement cycle and where the digital timer elapsed time is a sum of individual parameter measurements.

20. The measurement system of claim 19 where the measurement system comprises one or more sensing assemblies, one or more load surfaces, an accelerometer, electronic circuitry, a transceiver, and an energy supply, where the measurement system measures forces, such as an applied load, and transmits the measurement data to a secondary system for further processing and display.