ACTUATOR ASSEBMLY FOR PROSTHETIC OR ORTHOTIC JOINT

• US 20070156252A1
• Filed: 09/01/2005
• Published: 07/05/2007
• Est. Priority Date: 09/01/2005
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Jonsson, Helgi, Lecomte, Christophe, Ingimarsson, Gudni, Clausen, Arinbjorn
• Granted Patent: US 8,048,172 B2
• Time in Patent Office: Days
• US Class Current: 623/24
• CPC Class Codes: A61F 2/60 Artificial legs or feet or parts thereof
• CPC Class Codes: A61F 2/604 Joints for artificial legs A61F2/605, A61F2/64, A61F2/6607 take precedence
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/66 Feet; Ankle joints
• 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 2002/5016 adjustable
• CPC Class Codes: A61F 2002/5018 for adjusting angular orientation
• CPC Class Codes: A61F 2002/502 for adjusting length
• CPC Class Codes: A61F 2002/5021 for adjusting a position by translation along an axis
• CPC Class Codes: A61F 2002/5043 with rotation-limiting stops, e.g. projections or recesses
• CPC Class Codes: A61F 2002/5073 Helical springs, e.g. having at least one helical spring
• CPC Class Codes: A61F 2002/6614 Feet
• 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 2002/705 Electromagnetic data transfer
• CPC Class Codes: A61F 2002/7625 for measuring angular position
• 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

Abstract

Abstract of the Disclosure

A system and method associated with the movement of a limb. In one example, the system, such as a prosthetic or orthotic system, includes an actuator that actively controls, or adjusts, the angle between a foot unit and a lower limb member. The actuator preferably selectively locks during a desired phase in a gait cycle of the limb and minimizes friction against a rotor of the actuator. A processing module may control movement of the actuator based on data obtained from a sensor module. For instance, sensing module data may include information relating to the gait of a user and may be used to adjust the foot unit to substantially mimic the movement of a natural, healthy ankle. The system may further accommodate, for example, level ground walking, traveling up/down stairs, traveling up/down sloped surfaces, and various other user movements. In addition, the processing module may receive user input or display output signals through an external interface. For example, the processing module may receive a heel height input from the user.

Claims

1. A device configured to be attached to a limb, comprising:

a first portion;

a second portion, the first and second portions moveable relative to each other to mimic a natural human joint; and

an actuator comprising a rotor operatively coupled to a stator and a motor configured to rotate the rotor, the actuator coupling the first and second portions together and configured to adjust an angle between the first portion and the second portion,

wherein the actuator is selectively locked and unlocked during a desired phase of a gait cycle.

2. The device of Claim 1, wherein the actuator locks when in tension.

3. The device of Claim 2, wherein the actuator applies a friction force on the rotor to thereby inhibit the rotation of the rotor when the rotor and stator are in tension relative to each other.

4. The device of Claim 1, wherein the actuator further comprises a screw extending along a major axis of the actuator, the motor being disposed about the screw.

5. The device of Claim 4, wherein the rotor is a nut rotatably movable relative to the screw, and wherein a locking force is generated between a flange on the nut and a flange on a retainer disposed about the nut.

6. The device of Claim 5, wherein the nut and the screw are threadingly engaged and the locking force is further generated between threads on the nut and threads on the screw.

7. The device of Claim 1, wherein the actuator is further configured to inhibit the application of a load on the motor when a force is applied to the rotor.

8. The device of Claim 1, wherein the second portion is a prosthetic foot.

9. A device configured to be attached to a limb, comprising:

a first portion;

a second portion, the first and second portions moveable relative to each other to mimic a natural human joint;

an actuator comprising a rotor operatively coupled to a stator and a motor configured to rotate the rotor, the actuator coupling the first and second portions together and configured to adjust an angle between the first portion and the second portion; and

means for minimizing friction against the rotor.

10. The device of Claim 9, wherein the means comprises a ball bearing disposed between the stator and the rotor, the ball bearing configured to inhibit friction between the rotor and the stator.

11. The device of Claim 9, wherein the means is a magnet disposed between the rotor and the stator, the magnet configured to draw the rotor and the stator toward each other and away from a friction generating surface.

12. The device of Claim 9, wherein the second portion is a prosthetic foot and wherein the natural human joint is an ankle.

13. A device configured to be attached to a limb, comprising:

a first portion;

a second portion, the first and second portions moveable relative to each other to mimic a natural human joint; and

an actuator comprising a rotor operatively coupled to a stator and a motor configured to rotate the rotor, the actuator coupling the first and second portions together and configured to adjust an angle between the first portion and the second portion,

wherein the motor is disposed about the rotor.

14. The device of Claim 13, wherein the second portion is a prosthetic foot and wherein the natural human joint is an ankle.

15. The device of Claim 13, wherein the actuator further comprises a screw extending along a major axis of the actuator, the screw having a hollow portion.

16. The device of Claim 15 wherein the rotor is a nut rotatably movable relative to the screw.

17. The device of Claim 16, wherein the nut and the screw are threadingly engaged.

18. The device of Claim 13, wherein the actuator is further configured to inhibit the application of a load on the motor when a force is applied to the rotor.

19. A prosthetic device configured to be attached to a limb, comprising:

a prosthetic foot;

a pivot assembly attached to the prosthetic foot, the pivot assembly mimicking a natural human ankle joint;

a support member having an upper end and a lower end, wherein the lower end of the support member is operatively coupled to the pivot assembly; and

an actuator operatively coupled to the prosthetic foot and the support member, the actuator configured to adjust an angle between the support member and the prosthetic foot about the pivot assembly,

wherein the actuator is selectively locked and unlocked during a desired phase of a gait cycle of the prosthetic foot.

20. The device of Claim 19, wherein the actuator locks when in tension.

21. The device of Claim 20, wherein the actuator comprises a rotor coupled to a stator, the actuator configured to apply a friction force on the rotor to thereby inhibit the rotation of the rotor when the rotor and stator are in tension relative to each other.

22. The device of Claim 20, wherein the rotor is a nut and a locking force is generated between a flange on the nut and a flange on a retainer disposed about the nut.

23. The device of Claim 22, wherein the nut is threadingly engaged with and rotatably moveable relative to a screw, and wherein the locking force is further generated between threads on the screw and threads on the nut.

24. The device of Claim 19, wherein the actuator locks when the prosthetic foot is in a stance position between heel-strike and toe-off.

25. An actuator, comprising:

an elongate member extending about a major axis of the actuator;

a rotor rotatably coupled to the elongate member;

a stator operatively coupled to the rotor;

at least one magnet disposed between the rotor and the stator, the magnet configured to apply a magnetic force between the rotor and the stator; and

a motor configured to rotate the rotor relative to the elongate member,

wherein the at least one magnet is configured to minimize friction between the rotor and the stator.

26. The actuator of Claim 25, wherein the elongate member is a screw.

27. The actuator of Claim 26, wherein the screw is hollow.

28. The actuator of Claim 25, wherein the rotor and the screw are threadingly coupled.

29. A prosthetic device comprising the actuator of Claim 25, wherein the actuator adjusts an angle between a first portion and a second portion of the prosthetic device, the first and second portions moveable relative to each other to mimic a natural human joint.

30. The prosthetic device of Claim 29, wherein the second portion is a prosthetic foot and the natural human joint is an ankle.

31. An actuator, comprising:

an elongate member extending about a major axis of the actuator;

a rotor rotatably coupled to the elongate member;

a stator operatively coupled to the rotor;

a ball bearing disposed between the rotor and the stator; and

a motor configured to rotate the rotor relative to the elongate member,

wherein the ball bearing is configured to minimize friction between the rotor and the stator.

32. The actuator of Claim 31, wherein the elongate member is a screw.

33. The actuator of Claim 32, wherein the screw is hollow.

34. The actuator of Claim 32, wherein the rotor and the screw are threadingly coupled.

35. A prosthetic device comprising the actuator of Claim 31, wherein the actuator adjusts an angle between a first portion and a second portion of the prosthetic device, the first and second portions moveable relative to each other to mimic a natural human joint.

36. The prosthetic device of Claim 35, wherein the second portion is a prosthetic foot and the natural human joint is an ankle.

37. An actuator, comprising:

an elongate member extending about a major axis of the actuator;

a rotor rotatably coupled to the elongate member;

a stator operatively coupled to the rotor; and

a motor disposed about the rotor, the motor configured to rotate the rotor relative to the elongate member.

38. The actuator of Claim 37, wherein the rotor is actuated via a force without placing a load on the motor.

39. A prosthetic device comprising the actuator of Claim 37, wherein the actuator adjusts an angle between a first portion and a second portion of the prosthetic device, the first and second portions moveable relative to each other to mimic a natural human joint.

40. The prosthetic device of Claim 39, wherein the second portion is a prosthetic foot and the natural human joint is an ankle.

41. An actuator, comprising:

an elongate member extending about a major axis of the actuator;

a rotor rotatably coupled to the elongate member;

a retainer disposed about the rotor;

a stator operatively coupled to the rotor; and

a motor configured to rotate the rotor relative to the elongate member,

wherein the rotor and the retainer selectively engage to inhibit rotation of the rotor.

42. The actuator of Claim 41, wherein a flange on the rotor and a flange on the retainer selectively engage thereby generating a locking force to inhibit rotation of the rotor.

43. The actuator of Claim 41, wherein the elongate member is a screw and the rotor is a nut threadingly coupled to the screw.

44. The actuator of Claim 43, wherein a pitch between threads on the rotor and the screw generate a friction force between the rotor and the screw that is large enough to inhibit the relative rotation of the rotor and the screw when an axial load is applied to the rotor and/or the screw.

45. The actuator of Claim 41, wherein the rotor and the retainer engage, so as to generate a locking force, when the rotor and stator are in tension relative to each other.

46. A prosthetic device comprising the actuator of Claim 41, wherein the actuator adjusts an angle between a first portion and a second portion of the prosthetic device, the first and second portions moveable relative to each other to mimic a natural human joint.

47. The prosthetic device of Claim 46, wherein the second portion is a prosthetic foot and the natural human joint is an ankle.

48. The prosthetic device of Claims 47, wherein the rotor and the retainer selectively engage during a desired phase in a gait cycle of the prosthetic device to inhibit the rotation of the rotor.

49. A method of operating a prosthetic device attached to a limb, comprising:

providing a prosthetic device configured to attach to a limb, the device mimicking a natural human joint and having a first portion and a second portion, the portions moveable relative to each other about the joint;

providing an actuator coupled to the first portion and the second portion;

adjusting an angle between the first portion and the second portion; and

selectively locking and unlocking the actuator during a desired phase of a gait cycle.

50. The method of Claim 49, wherein selectively locking the actuator includes generating a friction force between a rotor of the actuator and a retainer disposed about the rotor.

51. The method of Claim 50, wherein selectively locking the actuator further includes generating a friction force between a rotor and a screw of the actuator.

52. The method of Claim 49, wherein selectively locking the actuator includes locking the actuator when a rotor and a stator of the actuator are in tension relative to each other.

53. The method of Claim 49, wherein selectively locking the actuator includes locking the actuator while in a stance position during the gait of the prosthetic device.

54. The method of Claim 49, wherein the natural human joint is a natural human ankle joint.

55. A method of operating a prosthetic device attached to a limb, comprising:

providing a prosthetic device configured to attach to a limb, the device mimicking a natural human joint and having a first portion and a second portion, the portions moveable relative to each other about the joint;

providing an actuator coupled to the first portion and the second portion;

adjusting an angle between the first portion and the second portion; and

actively minimizing friction against a rotor of the actuator during a selected desired phase of a gait cycle.

56. The method of Claim 55, wherein minimizing friction includes providing a magnet between the rotor and a stator of the actuator, the magnet configured to draw the stator and rotor toward each other.

57. The method of Claim 55, wherein minimizing friction includes providing a ball bearing between the rotor and a stator of the actuator.

58. The method of Claim 55, wherein friction is minimized during a swing phase of the gait cycle of the prosthetic device.

59. The method of Claim 55, wherein friction is minimized during a stance phase of the gait cycle of the prosthetic device.

60. The method of Claim 55, wherein the natural human joint is a natural human ankle joint.