APPARATUS AND METHOD FOR SENSING BONE POSITION AND MOTION

• US 20140031698A1
• Filed: 05/02/2013
• Published: 01/30/2014
• Est. Priority Date: 05/02/2012
• Status: Abandoned Application

• Current Assignee: San Diego State University (SDSU) Research Foundation
• Original Assignee: San Diego State University (SDSU) Research Foundation
• Inventors: OZTURK, Yusuf, MOON, Kee S.
• Application Number:
  US13/875,701
• Publication Number:
  US 20140031698A1
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/0077 Devices for viewing the surface of the body, e.g. camera, magnifying lens
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/4504 Bones A61B5/4547 takes precedence
• CPC Class Codes: A61B 5/4528 Joints A61B5/4533, A61B5/4538 take precedence
• CPC Class Codes: A61B 5/4887 Locating particular structures in or on the body
• CPC Class Codes: A61B 5/6825 Hand
• CPC Class Codes: A61B 5/6826 Finger

Abstract

This invention describes a novel photoplethysmographic system captures a joint shape change representing different positions of bones and tendons near the joint. At least one light source illuminates a joint interface and the light reflected from the joint location is captured by a photodiode sensor. Motions and positions of the bones surrounding the joint can be determined. One joint includes the knuckle. Finger lift-up motions, finger put-down motions, and finger bending events can be determined by monitoring a sensing area at the knuckle joint.

Claims

1. A method for measuring movement about a joint comprising:

positioning a photoplethysmographic sensor at a joint;

emitting light from the photoplethysmographic sensor to the joint; and

measuring an amount of reflected light from the joint.

2. The method of claim 1 wherein the photoplethysmographic sensor includes an optical sensor.

3. The method of claim 1 wherein the amount of reflected light is represented by a signal.

4. The method of claim 1 wherein the amount of reflected light over time from a particular joint produces a signature signal correlating to movement of one or more bones near the joint.

5. The method of claim 1 further comprising transmitting the signal wirelessly.

6. The method of claim 1 wherein the joint is a knuckle.

7. The method of claim 1 wherein a plurality of joints are provided with photoplethysmographic sensors and at least two of the plurality of joints are measured substantially simultaneously.

8. The method of claim 8 wherein the combination of a measurement from a first joint and a second joint depicts a movement.

9. The method of claim 8 wherein the combination of a measurements over a time from a first joint and a second joint depicts a movement of bones near the joint.

10. An apparatus for measuring movement comprising;

a strap for holding a photoplethysmographic sensor proximate a joint, the photoplethysmographic sensor further including;

a light emitter for emitting light into a joint region;

a light detector for receiving reflected light from the joint region, the light detector producing a signal in response to an amount of reflected light received at the light detector; and

a processing device for associating the amount of light reflected and received at the light detector to a position of bones near the joint.

11. The apparatus of claim 10 wherein the strap supports a plurality of photoplethysmographic sensors.

12. The apparatus of claim 10 wherein the strap supports a plurality of photoplethysmographic sensors, the strap allowing for adjustment of the position of the photoplethysmographic sensors with respect to the strap.

13. The apparatus of claim 10 wherein a spacing between a plurality of photoplethysmographic sensors can be adjusted to position of the photoplethysmographic sensors near a plurality of joints to be measured.

14. The apparatus of claim 10 wherein a spacing between a plurality of photoplethysmographic sensors can be adjusted to position of the photoplethysmographic sensors near a plurality of knuckles to be measured.

15. The apparatus of claim 10 wherein the light emitter for emitting light into a joint region includes a light emitting diode (LED).

16. The apparatus of claim 10 wherein the light detector for measuring reflected light from a joint region includes a photosensor.

17. A machine-readable medium providing instructions that, when executed by a machine, cause the machine to perform operations comprising:

measuring an amount of reflected light from a joint when bones near the joint are in a plurality of positions;

associating the amount of reflected light from a joint to a position the one or more plurality of positions; and

determining a position of the bones near a joint based on subsequent measures of an amount of reflected light from a joint.

18. The machine-readable medium of claim 17 for providing instructions that, when executed by a machine, cause the machine to perform operations further comprising determining a motion from a plurality of subsequent measures of reflected light of the bones near a joint.