Stance controller and related methods

• US 10,799,373 B2
• Filed: 09/14/2015
• Issued: 10/13/2020
• Est. Priority Date: 09/12/2014
• Status: Active Grant

• Current Assignee: Rehabilitation Institute of Chicago (Tenet Healthcare Corporation)
• Original Assignee: Rehabilitation Institute of Chicago (Tenet Healthcare Corporation)
• Inventors: Lenzi, Tommaso, Sensinger, Jon
• Primary Examiner(s): Woznicki, Jacqueline
• Application Number:
  US14/853,577
• Publication Number:
  US 20160074180A1
• Time in Patent Office: 1,856 Days
• 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 2/6607 Ankle joints
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2/72 Bioelectric control, e.g. myoelectric
• CPC Class Codes: A61F 2/74 fluid , i.e. hydraulic or pneumatic
• CPC Class Codes: A61F 2/80 Sockets, e.g. of suction type
• 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 2002/762 for measuring dimensions, e.g. a distance
• 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

Abstract

Systems and methods are disclosed for operating a joint of a prosthesis during a phase of stance. In an embodiment, a method for such operation comprises determining a joint angle of the joint, determining a walking speed of the prosthesis, retrieving a torque value from a lookup table stored in a memory, on the basis of the joint angle and the walking speed, and initiating a signal to apply a torque to the joint of the prosthesis in an amount based on the torque value.

Claims

1. A method for operating a joint of a prosthesis during a phase of stance, comprising:

a. determining a joint angle of the joint;

b. determining a walking speed magnitude of the prosthesis;

c. retrieving, using only the joint angle and the walking speed, a torque value from an intact leg'"'"'s quasi-stiffness profile,

wherein the quasi-stiffness profile is representative of torque data for an able-bodied joint,

wherein the able-bodied joint corresponds to the joint of the prosthesis, and

wherein the intact leg'"'"'s quasi-stiffness profile is encoded in a lookup table stored in a memory; and

d. initiating a signal to apply a torque to the joint of the prosthesis in an amount based on the torque value.

2. The method of claim 1, further comprising operating the prosthesis on a ground;

and determining an inclination of the ground at the position under the prosthesis;

wherein the step of retrieving the torque value from the lookup table stored in the memory is based on the inclination of the ground.

3. The method of claim 1, wherein the method is used to control the prosthesis during an early phase of stance, a mid-phase of stance, and a late phase of stance.

4. The method of claim 1, wherein the joint of the prosthesis is the knee joint.

5. A method for operating a prosthesis comprising a knee joint and an ankle joint during a phase of stance, comprising performing the method of claim 1 for the knee joint and performing the method of claim 1 for the ankle joint.

6. The method of claim 1, where the torque value is retrieved from the lookup table using interpolation.

7. The method of claim 1, wherein the signal to apply the torque to the joint of the prosthesis is modified, based on a weight of the user of the prosthesis, to normalize the torque to apply.

8. The method of claim 1, wherein the method is used to control the prosthesis during an early phase of stance, a mid-phase of stance, and a late phase of stance.

9. The method of claim 1, wherein the joint of the prosthesis is the knee joint.

10. A method for operating a prosthesis comprising a knee joint and an ankle joint during a phase of stance, comprising performing the method of claim 1 for the knee joint and performing the method of claim 1 for the ankle joint.

11. The method of claim 1, where the torque value is retrieved from the lookup table using interpolation.

12. The method of claim 1, wherein the signal to apply the torque to the joint of the prosthesis is modified, based on a weight of the user of the prosthesis, to normalize the torque to apply.

13. The method of claim 1, wherein the lookup table is selected from a plurality of lookup tables.

14. The method of claim 13, wherein each lookup table in the plurality of lookup tables is associated with a distinct phase of stance.

15. The method of claim 1, wherein the determining the walking speed magnitude of the prosthesis comprises measuring a shank orientation of a user of the prosthesis using a complementary filter.

16. A method for operating a joint of a prosthesis, comprising:

a. setting the prosthesis to a first stance phase and, while the prosthesis is in the first stance phase;

determining a first joint angle of the joint;

determining a first walking speed of the prosthesis;

retrieving, using only the first joint angle and the first walking speed, a first torque value from a first intact leg'"'"'s quasi-stiffness profile,

wherein the quasi-stiffness profile is representative of torque data for an able-bodied joint,

wherein the able-bodied joint corresponds to the joint of the prosthesis in the first stance, and,

wherein the intact leg'"'"'s quasi-stiffness profile is encoded in a first lookup table stored in a memory; and

initiating a first signal to apply a torque to the joint of the prosthesis in an amount based on the first torque value; and

b. setting the prosthesis to a second stance phase and, while the prosthesis is in the second stance phase;

determining a second joint angle of the joint;

determining a second walking speed of the prosthesis;

retrieving, using only the second joint angle and the second walking speed, a second torque value from a second intact leg'"'"'s quasi-stiffness profile,

wherein the quasi-stiffness profile is representative of torque data for the able-bodied joint in the second stance,

and wherein the intact leg'"'"'s quasi-stiffness profile is encoded in a second lookup table stored in a memory; and

initiating a second signal to apply a torque to the joint of the prosthesis in an amount based on the second torque value.

17. The method of claim 16, further comprising smoothing the second signal after a transition from the first stance phase to the second stance phase.

18. The method of claim 17, wherein the smoothing occurs during the 20 ms following the transition.

19. The method of claim 16, wherein step (b) occurs when a movement of an ankle joint of the prosthesis inverts between dorsiflexion and plantarflexion.