DUAL MODE CLOSED-LOOP SYSTEM AND METHOD FOR MEASURING A PARAMETER OF THE MUSCULAR-SKELETAL SYSTEM

• US 20100331663A1
• 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: Stein, Marc
• Granted Patent: US 9,592,010 B2
• Time in Patent Office: Days
• US Class Current: 600/407
• 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 dual-mode closed-loop measurement system (100) for capturing a transit time, phase, or frequency of energy waves propagating through a medium (122) is disclosed. A first device comprises an inductor drive circuit (102), an inductor (104), a transducer (106), and a filter (110). A second circuit comprises an inductor (114) and a transducer (116). A parameter to be measured is applied to the medium (122). The medium (122) is coupled between the first device and the second device. The first device initiates the transmit inductor (104) to query via inductive coupling to a receive inductor (114) on the second device via a first path. The inductor (114) triggers a transducer (116) on the second device to emit an energy wave that is propagated in the medium (122) and detected by the first device. The transit time of energy waves is affected by the parameter by known relationship.

Claims

1. A dual-mode closed loop measurement system evaluates a transit time of energy waves or pulses between two wireless modules to facilitate the measurement of physical or physiologic parameters within or affecting the interface between one or more of the medical devices and surrounding, but not limited to, tissue, bones, cartilage, fluids, or combinations thereof.

2. The measurement system of claim 1, where a first wireless module operating as the master can include a propagation tuned oscillator to maintain closed-loop feedback.

3. The measurement system of claim 2 further including a phase detector to correct phase differences between compared signals.

4. The measurement system of claim 3 further including a counter to count energy waves having propagated through a medium where the physical or physiologic parameters being measured are applied to the medium.

5. The measurement system of claim 4 where the physical or physiologic parameter being measured corresponds to energy wave transit time and where a known relationship exists between the medium and physical or physiological parameters.

6. The measurement system of claim 1, where a first wireless module and a second wireless module operates over a same transmission type over both paths of the wireless transmission coupling.

7. The measurement system of claim 6 where the transmission type of the first and second wireless modules is piezo-to-piezo or inductor to inductor.

8. The measurement system of claim 1 where a first wireless module and a second wireless module operates over a different transmission type over each path of the wireless transmission coupling.

9. The measurement system of claim 8 where one path of the wireless transmission coupling is inductor to inductor and another path of the wireless transmission coupling is piezo-to-piezo.

10. A dual-mode closed loop measurement system comprising an inductor drive circuit on a first device actively initiating by way of a transmit inductor a query via inductive coupling to a receive inductor on a second device via a first path, the receive inductor in response to the query triggers a transducer also on the second device to actively emit an energy wave in a second path back to the first device.

11. The system of claim 10 further including a transducer on the first device responsive to receiving the energy wave and where the first device continues the emission, propagation, and detection of energy waves.

12. The system of claim 11 further including a propagation medium coupled between the transducer of the first device and the transducer of the second device where the energy wave propagates through the medium to the transducer of the first device.

13. The system of claim 12 where the propagation medium is biological and where a transit time of the energy wave corresponds to a parameter applied to the medium.

14. The system of claim 12 where the propagation medium is one or more materials of an implanted device in the muscular-skeletal system.

15. The measurement system of claim 12 where the first device monitors the received energy wave for assessing the one or more properties of the propagation medium, whilst generating a pulse sequence that is fed back to the inductor drive circuit to create a close-loop feedback path.

16. The measurement system of claim 11 further including a capture of a transit time, phase, or frequency of energy waves propagating through the propagating medium.

17. A measurement system comprising:

a propagation medium;

a first device comprising;

an inductor;

a propagation tuned oscillator (PTO) including a driver circuit coupled to the inductor;

a transducer coupled to a first location of the propagation medium where the transducer detects an energy wave and provides a corresponding signal to the PTO;

a second device comprising;

an inductor operatively coupled to the inductor of the first device;

a transducer coupled to the propagation medium at a second location where the transducer of the second device emits an energy wave into the propagation medium in response to an inductively coupled signal from the first device to the second device.

18. The measurement system of claim 17 where the propagation medium is bone.

19. The measurement system of claim 17 where the propagation medium is a material of an implanted component to the muscular-skeletal system.

20. The measurement system of claim 17 where the measurement system forms a dual-mode closed-loop to maintain the emission, propagation, and detection of energy waves into the propagation medium and where the PTO captures one of a transit time, phase, or frequency of energy waves propagating through the propagating medium.