PROSTHETIC AND ORTHOTIC DEVICES AND METHODS AND SYSTEMS FOR CONTROLLING THE SAME

• US 20120083901A1
• Filed: 09/29/2011
• Published: 04/05/2012
• Est. Priority Date: 09/29/2010
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Langlois, David, Rittenhouse, Matheson, Roy, Yves
• Granted Patent: US 8,915,968 B2
• Time in Patent Office: Days
• US Class Current: 623/24
• CPC Class Codes: A61B 2560/0462 Apparatus with built-in sensors
• CPC Class Codes: A61B 5/1123 Discriminating type of movement, e.g. walking or running A61B5/1116, A61B5/112 take precedence
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6827 Feedback system for providing user sensation, e.g. by force, contact or position
• CPC Class Codes: A61F 2002/701 operated by electrically controlled means, e.g. solenoids or torque motors
• CPC Class Codes: A61F 2002/702 Battery-charging stations
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/705 Electromagnetic data transfer for implantable prostheses A61F2250/0002
• CPC Class Codes: A61F 2002/708 electrically self charging
• CPC Class Codes: A61F 2002/7615 Measuring means for implanting artificial joints A61F2/4657
• CPC Class Codes: A61F 2002/762 for measuring dimensions, e.g. a distance
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• 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 2002/7645 for measuring torque, e.g. hinge or turning moment, moment of force
• CPC Class Codes: A61F 2002/765 for measuring time or frequency

Abstract

Prosthetic and/or orthotic devices (PODS), control systems for PODS and methods for controlling PODS are provided. As part of the control system, an inference layer collects data regarding a vertical and horizontal displacement of the POD, as well as an angle of the POD with respect to gravity during a gait cycle of a user of the POD. A processor analyzes the data collected to determine a locomotion activity of the user and selects one or more control parameters based on the locomotion activity. The inference layer may be situated between a reactive layer control module and a learning layer control module of the control system architecture.

Claims

1. A motorized prosthetic or orthotic device (POD) comprising:

a first segment including a joint member and a second segment coupled with the first segment via the joint member;

an actuator configured to control motion of the second segment relative to the first segment;

a control system for operating the POD, comprising;

a reactive layer which commands and controls motion of the second segment relative to the first segment; and

an inference layer configured to receive an input stream comprising a first set of data accumulated during one or more gait cycles, the first set of data including one or more measurements of at least one of a vertical displacement associated with the first segment or the second segment, a horizontal displacement associated with the first segment or the second segment, and an angle associated with the first segment or the second segment with respect to gravity;

wherein the inference layer is configured to identify a locomotion activity of a user of the POD based at least on the first set of data and transmit information regarding the locomotion activity to the reactive layer to control motion of the second segment relative to the first segment.

2. The POD of claim 1, wherein the POD is a prosthetic knee, the first segment comprises a proximal connector configured to operably connect to a socket mountable to a thigh of the user, the second segment comprises a shank structure extending downwardly from the proximal connector, and the joint member comprises a motor configured to rotate the shank structure relative to the proximal connector.

3. The POD of claim 2, wherein the shank structure comprises a distal connector configured to connect to a prosthetic foot or ankle.

4. The POD of claim 1, wherein the control system further comprises a learning layer that identifies and responds to trends in use of the POD.

5. A method for controlling a motorized prosthetic or orthotic device (POD) of a user, wherein the POD comprises a first segment including a joint member and a second segment coupled with the first segment via the joint member, the method comprising:

receiving POD data at an inference layer control, wherein the POD data includes one or more measurements of at least one of a vertical displacement of the POD, a horizontal displacement of the POD, and an angle of the POD with respect to gravity;

determining a current locomotion activity of the user based on the POD data; and

transmitting information relating to the current locomotion activity to an actuator control.

6. The method of claim 5, wherein the first segment is a thigh segment and the second segment is a shank segment.

7. The method of claim 5, further comprising:

determining whether the current locomotion activity is a previous locomotion activity;

following the determination that the current locomotion is different from the previous locomotion activity, retrieving a plurality of parameters associated with the current locomotion activity; and

transmitting the plurality of parameters to the actuator control.

8. The method of claim 7, wherein the plurality of parameters comprise at least one of position set points, controller gains, velocity set points, and conditions for transitioning from one state to another state.

9. The method of claim 5, further comprising determining the current locomotion activity from one of fumbling around (FA), forward progression (FP), generation (GEN), dissipation (DIS), upward walking (UW), downward walking (DW), standing-to-sitting (STS), and sitting (SIT).

10. The method of claim 9, further comprising transitioning from the FA activity to the FP activity based on the POD data indicating a center-of-mass of the user is within a threshold location of a foot member coupled with the POD.

11. The method of claim 10, wherein indicating the center-of-mass of the user is within a threshold location of a foot member coupled with the POD is based on an absolute angle of the first segment and a velocity of the first segment.

12. The method of claim 9, further comprising transitioning from the FA activity to at least one of the GEN activity and the DIS activity based on a relative vertical displacement of the POD exceeding a threshold value.

13. The method of claim 9, further comprising transitioning from the FP activity to the DW activity based on at least one of a torque at the joint member exceeding a threshold value and the vertical displacement of the POD exceeding a threshold value.

14. The method of claim 9, further comprising transitioning from the FP activity to the UW activity based on at least one of an absolute angle of the first segment exceeding a threshold value upon foot strike of a foot member coupled with the POD and the vertical displacement of the POD exceeding a threshold value upon foot strike of the foot member.

15. The method of claim 9, further comprising transitioning from the FA activity to the STS activity based on a torque at the joint member exceeding a threshold value.

16. The method of claim 5, further comprising actuating the second segment relative to the first segment using the actuator control based at least in part on the determined locomotion activity.

17. The method of claim 5, further comprising determining at least one of an incline and a decline of a surface based on a relative vertical displacement of the POD.

18. The method of claim 5, further comprising determining a decline of a surface based at least on a torque at the joint member.

19. The method of claim 5, further comprising determining a center-of-mass of a user of the POD based at least on the angle of the POD with respect to gravity.

20. The method of claim 5, further comprising determining a cadence of the user based on at least one of the horizontal displacement of the POD between events and a time duration of a stance phase and swing phase of a user between events.

21. The method of claim 5, wherein the horizontal displacement is a relative horizontal displacement between foot strikes.

22. The method of claim 5, further comprising estimating a relative slope of terrain based on a relative horizontal displacement and a relative vertical displacement of the first segment and the second segment.

23. The method of claim 22, further comprising estimating the relative vertical displacement and the relative horizontal displacement based on one or more absolute first segment angles and one or more absolute second segment angles.

24. The method of claim 22, wherein the relative horizontal displacement is a horizontal displacement between foot strikes and the relative vertical displacement is a vertical displacement between foot strikes.

25. The method of claim 5, further comprising estimating the vertical displacement and the horizontal displacement of the POD based on a combination of a double integration of accelerometer signals and an absolute angle of the second segment.

26. The method of claim 5, further comprising estimating a relative vertical displacement and a relative horizontal displacement of the first segment and the second segment based on a sum of acceleration signals measured in a segment local coordinate system over specific periods of a gait cycle of the user.

27. The method of claim 5, wherein determining the current locomotion activity occurs at least once during each gait cycle of the user.

28. The method of claim 5, wherein the POD data comprises data from at least one of a first set of data, a second set of data, and a combination of the first set of data and the second set of data.

29. The method of claim 28, wherein the combination of the first set of data and the second set of data comprises an average of the first set of data and the second set of data.

30. The method of claim 28, wherein

the first set of data comprises one or more measurements of at least one of a vertical displacement of the first segment, a horizontal displacement of the first segment, and an angle of the first segment with respect to gravity, and

the second set of data comprises one or more measurements of at least one of a vertical displacement of the second segment, a horizontal displacement of the second segment, and an angle of the second segment with respect to gravity.

31. The method of claim 5, further comprising estimating the vertical displacement and the horizontal displacement of the POD based on a difference between a first angle at a first time and a second angle at a second time.

32. The method of claim 31, wherein the first angle at the first time is the angle of the POD at a foot-off event.

33. The method of claim 31, wherein the second angle at the second time is the angle of the POD at a foot strike event.

34. A control system for controlling a motorized prosthetic or orthotic device (POD) that is actuatable about a joint, the control system comprising:

a first inertial measurement unit (IMU) associated with a first segment of a user and configured to collect a first set of data, wherein the first set of data includes one or more measurements of at least one of a vertical displacement of the first segment, a horizontal displacement of the first segment, and an angle of the first segment with respect to gravity;

a second IMU associated with a second segment of the lower-limb POD of the user and configured to collect a second set of data, wherein the second set of data includes one or more measurements of at least one of a vertical displacement of the second segment, a horizontal displacement of the second segment, and an angle of the second segment with respect to gravity; and

an inference layer in communication with the first IMU and the second IMU and configured to;

receive the first set of data from the first IMU and the second set of data from the second IMU, and

identify a locomotion activity of the user based at least on the first set of data and the second set of data.

35. The control system of claim 34, wherein the first segment is a thigh segment and the second segment is a shank segment.

36. The control system of claim 34, wherein the inference layer is configured to transmit information regarding the locomotion activity to a reactive layer which commands and controls movement of the POD about the joint.

37. The control system of claim 36, wherein the inference layer is situated between the reactive layer and a learning layer.

38. The control system of claim 34, wherein the inference layer is configured to identify one of at least eight groups of locomotion activities, said at least eight groups comprising:

fumbling around (FA), forward progression (FP), generation (GEN), dissipation (DIS), upward walking (UW), downward walking (DW), standing-to-sitting (STS), and sitting (SIT).

39. The control system of claim 34, wherein the inference layer comprises a detection module, a performance assessment module and an activity definition module.

40. The control system of claim 34, wherein the first IMU is located at a distal portion of the first segment and the second IMU is located at a distal portion of the second segment.

41. The control system of claim 34, wherein each IMU includes an accelerometer and a gyroscope.