SYSTEMS AND METHODS FOR ACTUATING A PROSTHETIC ANKLE

• US 20110224804A1
• Filed: 02/28/2011
• Published: 09/15/2011
• Est. Priority Date: 02/12/2004
• Status: Active Grant

• Current Assignee: Ossur hf
• Original Assignee: Ossur hf
• Inventors: Ragnarsdottir, Heidrun G., Jonsson, Helgi, Clausen, Arinbjörn V.
• Granted Patent: US 9,271,851 B2
• Time in Patent Office: Days
• US Class Current: 623/47
• 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 2002/5018 for adjusting angular orientation
• CPC Class Codes: A61F 2002/5073 Helical springs, e.g. having at least one helical spring
• CPC Class Codes: A61F 2002/6642 Heels
• CPC Class Codes: A61F 2002/6685 S-shaped
• 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

Systems and methods for sensing actuating a prosthetic ankle are disclosed. In one example, the system, such as an actuated prosthetic ankle joint, detects that the user has moved to a relaxed position, such as sitting, reclining, crawling, or leaning. In response, the actuated prosthetic ankle joint actively adjusts the angle between the members of the ankle to a relaxed state. The system may further detect when the user has moved to exit the relaxed position, and may actively adjust the angle between the members of the ankle to an exit state.

Claims

1. A prosthetic system that mimics the movement of a natural ankle in a relaxed position, the prosthetic system comprising:

a prosthetic ankle joint comprising a foot unit and an upper member moveably attached to the foot unit to simulate a natural human ankle joint; and

a controller configured to automatically adjust the state of the prosthetic ankle joint, wherein the controller is configured to automatically adjust the prosthetic ankle joint to a relaxed state upon receiving data indicative of a user'"'"'s movement to a relaxed position.

2. The prosthetic system of claim 1, further comprising a sensor system, wherein the sensor system is configured to detect a user'"'"'s movement to the relaxed position whereupon the sensor system signals the controller to adjust the prosthetic ankle joint to the relaxed state.

3. The prosthetic system of claim 1, wherein the prosthetic ankle joint is an actuated prosthetic ankle joint.

4. The prosthetic system of claim 1, wherein the relaxed state comprises a low power mode.

5. The prosthetic system of claim 1, wherein the relaxed state comprises a desired angle between the foot unit and the upper member.

6. The prosthetic system of claim 2, wherein the sensor system comprises an accelerometer configured to measure the force of gravity on the sensor, whereupon the measured force is indicative of the angle of the prosthetic ankle joint relative to a ground surface, and wherein there is a range of angles indicative of the user'"'"'s movement to the relaxed position.

7. The prosthetic system of claim 2, wherein the sensor system comprises an accelerometer configured to measure the lateral acceleration of the sensor, whereupon there is a range of acceleration measurements indicative of the user'"'"'s movement to the relaxed position.

8. The prosthetic system of claim 2, wherein the sensor system comprises a timer configured to measure the time during which the sensor system measures parameters indicative of a user'"'"'s movement to the relaxed position, and wherein there is a range of time indicative of the user'"'"'s movement to the relaxed position.

9. The prosthetic system of claim 1, wherein the controller is further configured to automatically adjust the prosthetic ankle joint to an exit state upon receiving data indicative of a user'"'"'s movement to an exit position.

10. A prosthetic system for mimicking the natural movement of an ankle in a relaxed position, the prosthetic system comprising:

a prosthetic foot;

a pivot assembly attached to a first location on the prosthetic foot, wherein the first location is near a natural ankle location of the prosthetic foot;

a lower limb member extending in a tibial direction, the lower limb member having an upper end and a lower end, wherein the lower end of the lower limb member is operatively coupled to the pivot assembly; and

an actuator coupled to the prosthetic foot and to the lower limb member, wherein the actuator is configured to adjust an angle between the lower limb member and the prosthetic foot about the pivot assembly;

at least one sensor configured to detect a position of a user of the prosthetic system; and

a controller configured to operate the actuator;

wherein the at least one sensor is configured to transmit data to the controller indicative of when the user is in a relaxed position, said relaxed position determined by the user positioning the prosthetic system within a range of defined angles relative to a ground surface for a defined amount of time and the prosthetic system having an acceleration less than a maximum threshold value, and wherein the controller is configured to operate the actuator to cause an angle between the prosthetic foot and the lower limb assembly to increase about the pivot assembly such that the prosthetic foot becomes more plantarflexed relative to the lower limb assembly.

11. The prosthetic system of claim 10, wherein the at least one sensor comprises an accelerometer.

12. The prosthetic system of claim 10, wherein the actuator is configured to adjust the angle between the lower limb member and the prosthetic foot to at least ten degrees more than the angle at neutral position upon the controller receiving data indicative of the user being in said relaxed position.

13. The prosthetic system of claim 10, wherein the actuator is configured to adjust the angle after a delay of about one second or more from receiving data indicative of a user'"'"'s movement to said relaxed position.

14. The prosthetic system of claim 10, wherein the range of defined angles is between about 30 degrees and −

90 degrees.

15. The prosthetic system of claim 10, wherein the maximum threshold value of acceleration is about 1 m/s².