Actuator assembly for prosthetic or orthotic joint

• US 8,709,097 B2
• Filed: 10/31/2011
• Issued: 04/29/2014
• Est. Priority Date: 09/01/2005
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Clausen, Arinbjrn Viggo, Ingimarsson, Gudni, Lecomte, Christophe, Sigfusson, Larus, Jnsson, Helgi, Ragnarsdttir, Heirn Ggja
• Primary Examiner(s): Isabella, David
• Assistant Examiner(s): Woznicki, Jacqueline
• Application Number:
  US13/286,015
• Publication Number:
  US 20120078380A1
• Time in Patent Office: 911 Days
• Field of Search: 623/47, 623/24
• 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 for implantable prostheses A61F2002/30537
• CPC Class Codes: A61F 2002/5018 for adjusting angular orientation
• CPC Class Codes: A61F 2002/502 for adjusting length for implantable joints A61F2002/3055
• 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 for implantable prostheses A61F2250/0002
• 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

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 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, data may include information relating to a user'"'"'s gait and may be used to adjust the foot unit to substantially mimic the movement of a natural ankle. The system may accommodate level ground walking, traveling up/down stairs or sloped surfaces, and various other user movements. In addition, the processing module may receive user input, such as a heel height, or display output signals through an external interface.

Claims

1. A prosthetic ankle for attaching to a limb, comprising:

a prosthetic lower limb member;

a prosthetic foot movably coupled to the prosthetic lower limb member;

an actuator comprising;

a motor,

a first threaded member that extends along a longitudinal axis of the actuator and connects to the prosthetic lower limb member, the first threaded member having a first threaded portion and configured to move along the longitudinal axis relative to the motor, and

a second threaded member that extends along the longitudinal axis of the actuator and connects to the prosthetic foot, the second threaded member having a second threaded portion and configured to move along the longitudinal axis relative to the motor, the first and second threaded members extending from opposite sides of the motor and configured to move relative to each other,

wherein the motor is disposed circumferentially about at least a portion of the first and second threaded members, the motor configured to axially displace outer ends of one or both of the first and second threaded members to adjust an angle between the prosthetic lower limb member and the prosthetic foot, and wherein a pitch of threads of one or both of the first and second threaded members generates a locking force when an axial load is applied to at least one of the first and second threaded members to lock the angle between the prosthetic lower limb member and the prosthetic foot.

2. The prosthetic ankle of claim 1, wherein the first and second threaded portions threadingly engage and the locking force is generated between the threads of the first and second threaded portions.

3. The prosthetic ankle of claim 1, wherein the threads of the first threaded portion and the second threaded portion have the same pitch.

4. The prosthetic ankle of claim 1, wherein the pitch of the threads of one or both of the first and second threaded members is configured to generate the locking force during a desired phase of a gait cycle.

5. The prosthetic ankle of claim 4, wherein the pitch of the threads of one or both of the first and second threaded members is configured to allow movement of the actuator when the load is removed to adjust the angle between the prosthetic lower limb member and the prosthetic foot.

6. The prosthetic ankle of claim 1, wherein the actuator further comprises at least one magnet, and wherein the motor is disposed circumferentially about at least a portion of the magnet and the magnet is disposed circumferentially about at least a portion of the first and second threaded members.

7. A prosthetic ankle for attaching to a limb, comprising:

a prosthetic lower limb member;

a prosthetic foot movably coupled to the prosthetic lower limb member; and

an actuator operatively coupled to the prosthetic foot and the prosthetic lower limb member, comprising;

at least one magnet;

a rotor having a threaded portion;

a motor configured to rotate the rotor via the at least one magnet;

a screw that extends along a longitudinal axis of the actuator and connects to the prosthetic foot, the screw having a threaded portion and configured to move along the longitudinal axis relative to the motor;

wherein the motor is disposed circumferentially about at least a portion of the at least one magnet, the at least one magnet is disposed circumferentially about at least a portion of the rotor, the rotor is disposed circumferentially about at least a portion of the screw, and wherein rotation of the rotor axially moves the screw to adjust an angle between the prosthetic lower limb member and the prosthetic foot,

wherein a pitch of threads of one or both of the rotor and screw generates a locking force when an axial load is applied to the actuator to lock the angle between the prosthetic lower limb member and the prosthetic foot.

8. The prosthetic ankle of claim 7, wherein the threaded portions of the rotor and screw threadingly engage and a locking force is generated between threads of the rotor and screw.

9. The prosthetic ankle of claim 7, wherein threads of the threaded portions of the rotor and screw have the same pitch.

10. The prosthetic ankle of claim 7, wherein the pitch of threads of one or both of the rotor and screw is configured to generate the locking force during a desired phase of a gait cycle.

11. The prosthetic ankle of claim 10, wherein the pitch of the threads of one or both of the rotor and screw is configured to allow movement of the actuator when the axial load is removed to adjust the angle between the prosthetic lower limb member and the prosthetic foot.

12. The prosthetic ankle of claim 11, wherein the pitch of the threads of one or both of the rotor and screw is configured to allow movement of the actuator to adjust the angle between the prosthetic lower limb member and the prosthetic foot during a swing phase of the gait cycle.