INTEGRATED SENSOR FOR MEDICAL APPLICATIONS

• US 20100331704A1
• Filed: 06/29/2010
• Published: 12/30/2010
• Est. Priority Date: 06/30/2009
• Status: Active Grant

• Current Assignee: Howmedica Osteonics Corp. (Stryker Corporation)
• Original Assignee: OrthoSensor, Inc (Stryker Corporation)
• Inventors: Ellis, James, Stein, Marc
• Granted Patent: US 8,668,646 B2
• Time in Patent Office: Days
• US Class Current: 600/459
• 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 assemblage (1) for capturing a transit time, phase, or frequency of energy waves propagating through a medium is disclosed to measure a parameter of the muscular-skeletal system. The sensing assemblage (1) comprises a transducer (2) and a waveguide (3). The transducer (2) is coupled to the waveguide (3) at a first location. A second transducer (11) can be coupled to the waveguide (3) at a second location. An interface material that is transmissive to acoustic energy waves can be placed between transducers (402, 404) and a waveguide (414) to improve transfer. The interface material (408, 410) can affix the transducers (402, 404) to the waveguide (414). Alternatively, a reflecting feature (5) can be placed at a second location of the waveguide (3) to reflect acoustic waves back to the transducer (2) where transducer (2) emits energy waves into the medium and detects propagated energy waves.

Claims

1. A sensing assemblage comprising:

an ultrasound waveguide with two ends; and

a first transducer and second transducer each placed at one of the ends of the ultrasound waveguide where the first transducer and second transducer operate together to measure changes in the propagation characteristics of ultrasound waves within the waveguide.

2. The sensing assemblage of claim 1 where the waveguide comprises urethane.

3. The sensing assemblage of claim 1 where the waveguide comprises polyethylene.

4. The sensing assemblage of claim 1 where a series and parallel resonance of the first transducer does not overlap a series and parallel resonance of the second transducer.

5. The sensing assemblage of claim 4 where the waveguide is compressible.

6. The sensing assemblage of claim 5, where the first transducer emits a continuous wave or pulse and where electronic circuitry by way of the second transducer measures a change in a time of flight, differential time of flight, frequency, phase, or amplitude of the continuous wave or pulse.

7. The sensing assemblage of claim 6 where the sensing assemblage couples to a muscular-skeletal system to measure a force, load, or pressure.

8. The sensing assemblage of claim 7 where a relationship between waveguide length and applied force, load, or pressure is known and where the measurement of change in a time of flight, differential time of flight, frequency, phase, or amplitude of the continuous wave or pulse relates to a length of the waveguide.

9. The sensing assemblage of claim 8 where the waveguide is cylindrical in shape.

10. The sensing assemblage of claim 10, where the first transducer and the second transducer alternate between transmitting and receiving functions

11. A sensing assemblage comprising:

an ultrasound waveguide with a reflective feature; and

a transducer placed at one end of the ultrasound waveguide;

where the single transducer measures changes in the propagation characteristics of reflected ultrasound waves within the waveguide.

12. The sensing assemblage of claim 11, where the transducer alternates between transmitting and receiving.

13. The sensing assemblage of claim 12, where the waveguide length is less than 10 mm and where the waveguide is compressible.

14. The sensing assemblage of claim 13 further including a controller operatively coupled to the transducer to evaluate a change in a time of flight, differential time of flight, frequency, phase, or amplitude of the reflected ultrasound waves.

15. The sensing assemblage of claim 13 where an integer number of energy waves is maintained in the waveguide during a measurement.

16. A three-dimensional sensing assemblage comprising:

a first sensing assemblage along a x-axis;

a second sensing assemblage along a y-axis; and

a third sensing assemblage along a z-axis, where the first, second, and third sensing assemblages include at least one reflective feature along one or more waveguides to share transducers.

17. The sensing assemblage of claim 16 where the sensing assemblage includes at least one waveguide.

18. The sensing assemblage of claim 17 further including a first, second, and third transducer coupled respectively to the waveguide in the x-axis, y-axis, and z-axis.

19. The sensing assemblage of claim 18 where propagation of an energy wave in the sensing assemblage is uni-directional.

20. The sensing assemblage of claim 16 where a reflected energy wave is propagated in the sensing assemblage.