Systems and methods for processing limb motion

• US 20060135883A1
• Filed: 12/22/2005
• Published: 06/22/2006
• Est. Priority Date: 12/22/2004
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Arion Banki Hf
• Inventors: Ragnarsdottir, Heidrun G., Jónsson, Helgi, Clausen, Arinbjörn Viggo
• Granted Patent: US 7,811,333 B2
• Time in Patent Office: Days
• US Class Current: 600/546
• 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 system for analyzing the movement of a device associated with a limb, the system comprising:

at least one accelerometer configured to generate a time series of motion signals indicative of a movement of a device associated with a limb; and

a process module in communication with the at least one accelerometer, the process module comprising;

a filter configured to process the time series of motion signals received from the at least one accelerometer and configured to generate a plurality of filtered signals; and

a comparison module configured to compare the plurality of filtered signals with a plurality of sample signals, wherein the comparison module is further configured to identify limb-motion events associated with the movement of the device associated with the limb.

2. The system of claim 1, wherein the at least one accelerometer comprises a gyroscope.

3. The system of claim 1, wherein the time series of motion signals comprises at least one of forward, inward and downward linear acceleration signals.

4. The system of claim 1, wherein the filter comprises an autoregressive filter.

5. The system of claim 4, wherein the filter comprises a Kalman filter.

6. The system of claim 1, further comprising a database configured store the plurality of sample signals.

7. The system of claim 1, wherein the process module comprises a machine executable software module.

8. The system of claim 1, wherein the limb is an artificial limb.

9. The system of claim 8, wherein the artificial limb comprises one of a prosthetic device and an orthotic device.

10. A prosthetic device being movable about a joint location and comprising the system of claim 1.

11. The prosthetic device of claim 10, wherein the comparison module is further configured to generate a control signal for adjusting the prosthetic device.

12. The prosthetic device of claim 11, further comprising an actuator configured to control movement of the prosthetic device according to the control signal.

13. The prosthetic device of claim 12, wherein the joint location is an ankle-joint location.

14. 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 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.

15. The method of claim 14, wherein said receiving further comprises receiving the time series of motion signals from at least one of an accelerometer and a gyroscope.

16. The method of claim 15, wherein the time series of motion signals includes a continuous acceleration signal.

17. The method of claim 16, wherein the continuous acceleration signal comprises a non-uniform sampling rate.

18. The method of claim 14, wherein said processing further comprises comparing the filtered signals with a set of sample signals.

19. The method of claim 14, wherein the limb-motion category comprises at least one of:

inclination, declination, step, and non-step.

20. The method of claim 14, additionally comprising identifying at least one limb-motion event.

21. The method of claim 20, 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.

22. 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 a particular motion pattern.

23. The method of claim 22, wherein said processing includes filtering the plurality of sensor signals with a predictive filter.

24. The method of claim 22, wherein the plurality of motion patterns includes calibration data associated with at least one limb-motion event.

25. The method of claim 22, wherein the device is a prosthetic ankle device.

26. 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 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 to identify at least one limb-motion category.

27. The system of claim 26, further comprising means for identifying at least one limb-motion event, 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.

28. A system for processing signals associated with the movement of a prosthetic ankle device, the system comprising:

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

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

means for comparing the processed sensor signals to a plurality of motion patterns so as to associate the processed sensor signals with a particular motion pattern.

29. The system of claim 28, wherein the motion pattern is a gait pattern.

30. The system of claim 28, further comprising the prosthetic ankle device.