SYSTEMS AND METHODS FOR PROCESSING LIMB MOTION

• US 20100324456A1
• Filed: 08/12/2010
• Published: 12/23/2010
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Ragnarsdóttir, Heidrun G., Jónsson, Helgi, Clausen, Arinbjörn Viggo
• Granted Patent: US 9,078,774 B2
• Time in Patent Office: Days
• US Class Current: 600/592
• CPC Class Codes: A61B 5/112 Gait analysis
• CPC Class Codes: A61B 5/4851 Prosthesis assessment or monitoring
• CPC Class Codes: A61F 2/6607 Ankle joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/6657 having a plate-like or strip-like spring element, e.g. an energy-storing cantilever spring keel
• CPC Class Codes: A61F 2002/701 operated by electrically controlled means, e.g. solenoids or torque motors
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/763 for measuring spatial position, e.g. global positioning system [GPS]
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2002/764 for measuring acceleration
• CPC Class Codes: A61F 2002/7665 for measuring temperatures
• CPC Class Codes: A61F 2002/7685 located on natural or sound-site limbs, e.g. comparison measuring means

Abstract

Control systems and methods are disclosed for processing a time series of signals associated with the movement of a device associated with a limb. The time series of motion signals is filtered, such as thorough an autoregressive filter, and compared to stored data sets representing a limb-motion event and/or phase. In certain examples, a plurality of accelerometers generate the time series of motion signals based at least on acceleration measurements in three orthogonal directions and/or planes. The acceleration measurements may relate to the movement of an artificial limb, such as a prosthetic or orthotic device. Upon determining an event and/or phase of limb motion, the control system may trigger an actuator to appropriately adjust one or more prosthetic or orthotic joints.

Claims

1. A method of processing signals associated with the movement of a device associated with a limb, the method comprising:

receiving a time series of motion signals indicative of a movement of a device associated with a limb;

filtering selected ones of the time series of motion signals; and

processing the filtered signals to identify at least one limb-motion category.

2. The method of claim 1, wherein said receiving comprises receiving the time series of motion signals from at least one sensor.

3. The method of claim 2, wherein the at least one sensor comprises an accelerometer or a gyroscope.

4. The method of claim 2, wherein the time series of motion signals includes a continuous acceleration signal.

5. The method of claim 4, wherein the continuous acceleration signal comprises a non-uniform sampling rate.

6. The method of claim 1, wherein said processing further comprises comparing the filtered signals with a set of sample signals.

7. The method of claim 6, wherein said processing further comprises identifying at least one limb-motion event.

8. The method of claim 7, wherein the at least one limb-motion event comprises at least one of:

heel strike, toe down, heel off, toe off, midswing and end of swing.

9. The method of claim 1, wherein the limb-motion category comprises at least one of:

inclination, declination, step and non-step.

10. A method of processing signals associated with the movement of a device associated with a limb, the method comprising:

receiving a plurality of sensor signals indicative of a motion of a device associated with a limb;

processing the plurality of sensor signals with a time series analysis; and

comparing the processed sensor signals to a plurality of motion patterns so as to associate the processed sensor signals with at least one of the plurality of motion patterns.

11. The method of claim 10, wherein said processing includes filtering the plurality of sensor signals with a predictive filter.

12. The method of claim 10, wherein said processing includes filtering the plurality of sensor signals with an autoregressive filter.

13. The method of claim 12, wherein said processing includes filtering the plurality of sensor signals with a Kalman filter.

14. The method of claim 10, wherein the plurality of motion patterns includes calibration data associated with at least one limb-motion event.

15. The method of claim 10, wherein the at least one limb-motion event comprises at least one of toe-off and heel-strike events.

16. The method of claim 10, wherein the device associated with the limb comprises an actively-adjustable prosthetic device.

17. The method of claim 16, additionally comprising generating the plurality of sensor signals with at least one accelerometer attached to the actively-adjustable prosthetic device.

18. A system for processing signals associated with the movement of a device associated with a limb, the system comprising:

means for receiving a time series of motion signals indicative of a movement of a device associated with a limb;

means for filtering selected ones of the time series of motion signals; and

means for processing the filtered signals by comparing the filtered signals with stored patterns to identify at least one limb-motion category related to the movement of the device associated with the limb.

19. The system of claim 18, further comprising means for identifying at least one limb-motion event from the processed signals, wherein the at least one limb-motion event includes at least one of:

heel strike, toe down, heel off, toe off, midswing and end of swing.

20. The system of claim 18, wherein the at least one limb-motion category comprises at least one of level ground walking, walking up or down stairs, walking up or down ramps and running.