Hybrid terrain-adaptive lower-extremity systems

• US 9,554,922 B2
• Filed: 09/01/2009
• Issued: 01/31/2017
• Est. Priority Date: 09/04/2008
• Status: Active Grant

• Current Assignee: Otto Bock HealthCare LP (Nader Holding GmbH & Co. KG)
• Original Assignee: BionX Medical Technologies, Inc. (Ottobock SE & Co. KGaA)
• Inventors: Casler, Rick, Herr, Hugh M.
• Primary Examiner(s): Willse, David H
• Application Number:
  US12/551,845
• Publication Number:
  US 20100174385A1
• Time in Patent Office: 2,709 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• 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 2002/5003 having damping means, e.g. shock absorbers for implantable joints A61F2002/30563
• CPC Class Codes: A61F 2002/5007 having elastic means different from springs, e.g. including an elastomeric insert elastic coating A61F2002/3007; springs A61F2002/5072; plate-like springs for feet A61F2002/6657
• CPC Class Codes: A61F 2002/5018 for adjusting angular orientation
• CPC Class Codes: A61F 2002/503 for adjusting elasticity, flexibility, spring rate or mechanical tension
• CPC Class Codes: A61F 2002/5033 for adjusting damping damping means A61F2002/5003
• CPC Class Codes: A61F 2002/5079 Leaf springs A61F2002/6657 takes precedence
• CPC Class Codes: A61F 2002/5087 Sound-damping or noise-reducing means
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/6836 Gears specially adapted therefor, e.g. reduction gears
• 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 2002/7625 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 2002/7665 : for measuring temperatures
• CPC Class Codes: A61F 2005/0155 : with actuating means
• CPC Class Codes: A61F 2005/0169 : with damping means
• CPC Class Codes: A61H 1/0266 : Foot
• CPC Class Codes: A61H 2003/001 : on steps or stairways
• CPC Class Codes: A61H 3/00 : Appliances for aiding patients or disabled persons to walk about apparatus for helping babies to walk A47D13/04; orthopaedic devices for correcting deformities of, or supporting, limbs A61F5/0102; exercising apparatus for the feet or toes A63B23/10; stairways or ramps E04F11/00
• CPC Class Codes: B25J 9/0006 : Exoskeletons, i.e. resembling a human figure
• CPC Class Codes: G01L 5/0028 : Force sensors associated with force applying means G01L5/0052, G01L5/0057, G01L5/0061 take precedence
• CPC Class Codes: G01L 5/0061 : Force sensors associated with industrial machines or actuators for the specific machine or actuator involved see relevant class, e.g. F01, F04, F16, B66, E21
• CPC Class Codes: G01P 21/00 : Testing or calibrating of apparatus or devices covered by the preceding groups
• CPC Class Codes: H02K 7/06 : Means for converting reciprocating motion into rotary motion or vice versa
• CPC Class Codes: H02K 7/116 : with gears

Abstract

Hybrid terrain-adaptive lower-extremity apparatus and methods that perform in a variety of different situations by detecting the terrain that is being traversed, and adapting to the detected terrain. In some embodiments, the ability to control the apparatus for each of these situations builds upon five basic capabilities: (1) determining the activity being performed; (2) dynamically controlling the characteristics of the apparatus based on the activity that is being performed; (3) dynamically driving the apparatus based on the activity that is being performed; (4) determining terrain texture irregularities (e.g., how sticky is the terrain, how slippery is the terrain, is the terrain coarse or smooth, does the terrain have any obstructions, such as rocks) and (5) a mechanical design of the apparatus that can respond to the dynamic control and dynamic drive.

Claims

1. A computer-implemented method comprising:

determining an inertial pose trajectory, based on a wearer intent, of at least one location on or coupled to an apparatus within a swing phase of a gait cycle prior to foot strike, the inertial pose trajectory defined as a matrix comprising at least two of;

an orientation component of the at least one location on or coupled to the apparatus, a translation component of the at least one location on or coupled to the apparatus, or a velocity component of the at least one location on or coupled to the apparatus, the apparatus one of a lower-extremity prosthetic, a lower-extremity orthotic, or a lower-extremity exoskeleton to be coupled to the wearer;

determining a foot slope based on the inertial pose trajectory;

adjusting joint articulation of a portion of the apparatus during the same swing phase of the gait cycle prior to foot strike, based on the inertial pose trajectory and the foot slope;

evaluating a heel-first strategy and a toe-first strategy in view of a projected force imparted on an ankle joint of the apparatus;

selecting the heel-first strategy or the toe-first strategy based on which strategy minimizes the projected force during a period of time between when a foot member of the apparatus strikes the underlying terrain to when the foot member is positioned in a flat-foot position relative to the underlying terrain; and

adjusting an ankle angle of the apparatus in accordance with the selected strategy.

2. The computer-implemented method of claim 1, wherein the at least one location on or coupled to the apparatus comprises a location between and including an ankle joint and a knee joint.

3. The computer-implemented method of claim 2, wherein the at least one location on or coupled to the apparatus comprises the ankle joint.

4. The method of claim 2, wherein the ankle joint is connected to the foot member and a first end of a lower leg member of the apparatus, and the knee joint is connected to an opposite end of the lower leg member.

5. The computer-implemented method of claim 1, wherein adjusting the articulation of the portion of the apparatus comprises adjusting articulation of a foot member or ankle angle to a heel down position when a predetermined condition of the inertial pose trajectory is indicative of underlying terrain corresponding to level ground, an ascending ramp, or a descending ramp.

6. The computer-implemented method of claim 1, wherein adjusting the articulation of the portion of the apparatus comprises adjusting articulation of a foot member or ankle angle to a toe down position when a predetermined condition of the inertial pose trajectory is indicative of the presence of an ascending stair or a descending stair in underlying terrain.

7. The computer-implemented method of claim 6, further comprising adjusting the articulation of a foot member or ankle angle to a dorsi flexed position relative to a lower leg member of the apparatus when a predetermined condition of the inertial pose trajectory is representative of the presence of an ascending stair.

8. The computer-implemented method of claim 6, further comprising adjusting the articulation of a foot member or ankle angle to a plantar flexed position relative to a lower leg member of the apparatus when a predetermined condition of the inertial pose trajectory is representative of the presence of a descending stair.

9. The computer-implemented method of claim 1, wherein adjusting the articulation of the portion of the apparatus comprises:

adjusting the articulation of a foot member or ankle angle to a heel down position when a predetermined condition of the inertial pose trajectory is representative of the presence of level ground, an ascending ramp, or a descending ramp in underlying terrain; and

adjusting the articulation of the foot member or ankle angle to a toe down position when the predetermined condition of the trajectory is representative of the presence of an ascending stair or a descending stair in underlying terrain.

10. The computer-implemented method of claim 1, wherein adjusting the articulation of the portion of the apparatus comprises adjusting the articulation of a foot member or ankle angle to a predetermined orientation when the inertial pose trajectory satisfies a predetermined condition.

11. The method of claim 1, comprising analyzing the inertial pose trajectory relative to at least one predetermined inertial pose trajectory model to estimate an underlying terrain condition.

12. The method of claim 1, wherein determining the inertial pose trajectory comprises estimating a velocity vector attack angle of a portion of the apparatus.

13. The method of claim 12, comprising:

determining a property of an underlying terrain based on whether the velocity vector attack angle lies within a predetermined range; and

controlling the at least one of an impedance, ankle angle, position and torque of the apparatus based on whether the velocity vector attack angle lies within a predetermined range.

14. The method of claim 1, wherein the at least one location on or coupled to the apparatus comprises a location above the foot member.

15. The method of claim 1, wherein the inertial pose trajectory comprises an in-flight trajectory.

16. The method of claim 1, comprising controlling at least one of joint impedance, position or torque of the apparatus.

17. The method of claim 1, wherein determining the inertial pose trajectory comprises determining a translation of the at least one location on or coupled to the apparatus in at least two independent directions.

18. The method of claim 17, wherein determining the translation of the at least one location on or coupled to the apparatus comprises determining the translation in a substantially horizontal direction and a substantially vertical direction.

19. The method of claim 18, wherein the substantially horizontal direction and the substantially vertical direction comprise velocity components that define a velocity vector attack angle of the at least one location on or coupled to the apparatus.

20. The method of claim 1, wherein determining the inertial pose trajectory comprises determining a path of the at least one location of the apparatus or the point on the wearer coupled to the apparatus within a plane.

21. The method of claim 20, wherein the plane is substantially a sagittal plane.

22. The method of claim 1, wherein determining the inertial pose trajectory comprises determining a pitch angle and a translation component of the at least one location on or coupled to the apparatus.

23. The method of claim 1, wherein determining the inertial pose trajectory comprises determining at least one of an orientation component, a velocity component, a translation component, a position component and an angle component.

24. The method of claim 1, wherein the inertial pose trajectory comprises a plurality of orientation components.

25. The method of claim 1, wherein the inertial pose trajectory comprises a plurality of translation components.

26. The method of claim 1, wherein the inertial pose trajectory comprises a plurality of velocity components.

27. The method of claim 1, wherein the inertial pose trajectory is a function of time or space comprising three unit vectors defining a coordinate frame and a fourth vector defining an origin.

28. The method of claim 1, further comprising estimating a condition of underlying terrain based on the determining of the at least two components of the inertial pose trajectory, based on wearer intent, of the at least one location on or coupled to the apparatus.

29. The method of claim 28, wherein adjusting articulation of the portion of the apparatus includes adjusting an equilibrium position and an impedance in accordance with the condition of the underlying terrain.

30. The method of claim 1, wherein determining the at least two components of the inertial pose trajectory, based on wearer intent, of the at least one location on or coupled to the apparatus comprises collecting information from an inertial measurement unit.

31. The method of claim 1, further comprising adjusting impedance of the portion of the apparatus during the swing phase of the gait cycle based on the inertial pose trajectory.

32. The method of claim 1, wherein adjusting articulation of the portion of the apparatus comprises modulating at least one of a joint equilibrium and impedance of a portion of the apparatus during the swing phase of the gait cycle based on the inertial pose trajectory.

33. The method of claim 1, further comprising sending an articulation adjustment signal to a controller of the apparatus based on the determined inertial pose trajectory during the same swing phase of the gait cycle prior to foot strike.

34. The method of claim 1, wherein adjusting articulation of the portion of the apparatus comprises adjusting articulation of a foot member or ankle angle to conform to an angle defined by a vertical translation and a horizontal translation of the at least one location on or coupled to the apparatus.

35. The method of claim 1, wherein adjusting articulation of the portion of the apparatus comprises adjusting at least one of an impedance and an ankle angle equilibrium of the apparatus to minimize a cost function, wherein the cost function is based on at least one of a foot strike force and a foot flat force.

36. A method for discriminating between properties of terrain underlying a lower extremity prosthetic, orthotic, or exoskeleton apparatus to be worn by a wearer, the apparatus to comprise a foot member, a lower leg member, and an ankle joint for connecting the foot member to the lower leg member, the method comprising:

determining an inertial pose trajectory, based on a wearer intent, of at least one location on or coupled to the apparatus within a swing phase of a gait cycle prior to foot strike, the inertial pose trajectory defined as a matrix comprising at least two of;

an orientation component of the at least one location on or coupled to the apparatus, a translation component of the at least one location on or coupled to the apparatus, or a velocity component of the at least one location on or coupled to the apparatus;

determining a foot slope based on the inertial pose trajectory;

estimating a velocity vector attack angle of a portion of the apparatus during the same swing phase of the gait cycle prior to foot strike based at least in part on the inertial pose trajectory;

determining whether the velocity vector attack angle lies within a predetermined range;

determining a property of an underlying terrain based on;

a determination that the velocity vector attack angle lies within the predetermined range, and

the foot slope;

adjusting at least one of joint impedance or ankle angle equilibrium during the same swing phase of the gait cycle prior to foot strike based on the property; and

adjusting at least one of the impedance or the ankle angle equilibrium to minimize a projected force imparted on the lower leg member during a period of time between when the foot member strikes the underlying terrain to when the foot member is positioned in a flat-foot position relative to the underlying terrain.

37. A method for controlling at least one of joint impedance, position or torque of a lower extremity prosthetic, orthotic, or exoskeleton apparatus to be worn by a wearer, the apparatus to comprise a foot member, a lower leg member, and an ankle joint for connecting the foot member to the lower leg member, the method comprising:

determining an inertial pose trajectory, based on a wearer intent, of at least one location on or coupled to the apparatus within a swing phase of a gait cycle prior to foot strike, the inertial pose trajectory defined as a matrix comprising at least two of;

an orientation component of the at least one location on or coupled to the apparatus, a translation component of the at least one location on or coupled to the apparatus, or a velocity component of the at least one location on or coupled to the apparatus;

determining a foot slope based on the inertial pose trajectory;

estimating a velocity vector attack angle of a portion of the apparatus during the same swing phase of the gait cycle prior to foot strike based at least in part on the inertial pose trajectory;

determining whether the velocity vector attack angle lies within a predefined range;

adjusting a joint position of the foot member or an ankle angle of the apparatus within the same swing phase of the gait cycle prior to foot strike to a toe down position based on;

a determination that the velocity vector attack angle lies within a predefined range; and

the foot slope; and

adjusting at least one of an impedance or an ankle angle equilibrium of the apparatus to minimize a projected force imparted on the lower leg member during a period of time between when the foot member strikes the underlying terrain to when the foot member is positioned in a flat-foot position relative to the underlying terrain.

38. A method for discriminating between properties of terrain underlying a lower extremity prosthetic, orthotic, or exoskeleton apparatus to be worn by a wearer, the apparatus to comprise a foot member, a lower leg member, and an ankle joint for connecting the foot member to the lower leg member, the method comprising:

determining an inertial pose trajectory, based on a wearer intent, of at least one location on or coupled to the apparatus within a swing phase of a gait cycle prior to foot strike, the inertial pose trajectory defined as a matrix comprising at least two of;

an orientation component of the at least one location on or coupled to the apparatus, a translation component of the at least one location on or coupled to the apparatus, or a velocity component of the at least one location on or coupled to the apparatus;

determining a foot slope based on the inertial pose trajectory;

estimating a velocity vector attack angle of a portion of the apparatus during the same swing phase of the gait cycle prior to foot strike based at least in part on the inertial pose trajectory;

determining whether the velocity vector attack angle lies within a predetermined range;

determining a property of an underlying terrain based on;

a determination that the velocity vector attack angle lies within the predetermined range, and

the foot slope;

controlling at least one of joint impedance, ankle angle equilibrium or joint torque of the apparatus during the same swing phase of the gait cycle prior to foot strike based on the property; and

adjusting at least one of the joint impedance or the ankle angle equilibrium of the apparatus to minimize a projected force imparted on the lower leg member during a period of time between when the foot member strikes the underlying terrain to when the foot member is positioned in a flat-foot position relative to the underlying terrain.

39. The method of claim 38, comprising adjusting a position of the foot member or ankle angle to a heel down position when the velocity vector attack angle falls outside of the predetermined range.

40. The method of claim 38, wherein the foot member is attachable to a foot of the wearer and the lower leg member is attachable to a leg of the wearer.

41. The method of claim 38, wherein the foot member and lower leg member are adapted to replace the foot and lower leg of the wearer.

42. The method of claim 38, wherein determining a property of an underlying terrain comprises determining the presence of an ascending stair or a descending stair in the underlying terrain.

43. The method of claim 38, wherein determining a property of an underlying terrain comprises determining the presence of level ground, an ascending ramp, or a descending ramp in the underlying terrain.

44. The method of claim 38, wherein the predetermined range of velocity vector attack angle comprises a range below a threshold value.

45. The method of claim 43, wherein the threshold value comprises a positive value.

46. The method of claim 45, wherein controlling the ankle angle of the apparatus comprises adjusting articulation of the foot member or ankle angle to a toe down position when the property of the underlying terrain comprises the presence of an ascending stair or a descending stair.

47. The method of claim 46, wherein controlling the ankle angle of the apparatus comprises adjusting the articulation of the foot member or ankle angle to a heel down position when the property of the underlying terrain comprises the presence of level ground, an ascending ramp, or a descending ramp.

48. The method of claim 38, wherein the property of the underlying terrain comprises the presence of an ascending stair or a descending stair when the velocity vector attack angle falls within the predetermined range threshold.

49. The method of claim 38, wherein the property of the underlying terrain comprises the presence of level ground, an ascending ramp, or a descending ramp when the velocity vector attack angle does not fall within the predetermined range threshold.

50. The method of claim 38, wherein the velocity vector attack angle of the portion of the apparatus comprises an angle between a vertical direction and a direction of velocity of the ankle joint.

51. The method of claim 38, wherein estimating the velocity vector attack angle of the portion of the apparatus comprises estimating the velocity vector attack angle of the ankle joint of the apparatus.