Method for controlling an artificial orthotic or prosthetic kneejoint

• US 9,968,468 B2
• Filed: 07/07/2014
• Issued: 05/15/2018
• Est. Priority Date: 08/22/2013
• Status: Active Grant

• Current Assignee: Otto Bock Healthcare Products GmbH (Albatros Son Holding BV)
• Original Assignee: Otto Bock Healthcare Products GmbH (Albatros Son Holding BV)
• Inventors: Auberger, Roland, Seyr, Martin, Mandl, Clemens, Seifert, Dirk, Dietl, Hans
• Primary Examiner(s): Willse, David H
• Application Number:
  US14/911,549
• Publication Number:
  US 20160206447A1
• Time in Patent Office: 1,408 Days
• Field of Search: None
• CPC Class Codes: A61F 2/482 Electrical means
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/68 Operating or control means
• CPC Class Codes: A61F 2/70 electrical
• CPC Class Codes: A61F 2002/5007 having elastic means different from springs, e.g. including an elastomeric insert
• CPC Class Codes: A61F 2002/503 for adjusting elasticity, flexibility, spring rate or mechanical tension
• CPC Class Codes: A61F 2002/5033 for adjusting damping
• CPC Class Codes: A61F 2002/5072 having spring elements
• CPC Class Codes: A61F 2002/6818 for braking
• 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 2002/764 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 2005/0155 with actuating means
• CPC Class Codes: A61F 2250/0012 for adjusting elasticity, flexibility, spring rate or mechanical tension
• CPC Class Codes: A61F 2250/0096 Markers and sensors for detecting a position or changes of a position of an implant, e.g. RF sensors, ultrasound markers
• CPC Class Codes: A61F 5/0123 for the knees A61F5/0106 takes precedence

Abstract

A method for controlling an artificial orthotic or prosthetic knee joint, on which a lower-leg component is arranged and with which a resistance device is associated, the bending resistance (R) of which resistance device is changed in dependence on sensor data that are determined by means of at least one sensor during the use of the orthotic or prosthetic knee joint, wherein a linear acceleration (a_F) of the lower-leg component is determined, the determined linear acceleration (a_F) is compared with at least one threshold value, and, if a threshold value of the linear acceleration (a_F) of the lower-leg component is reached, the bending resistance (R) is changed.

Claims

1. A method for controlling an artificial orthotic or prosthetic knee joint, on which a below-knee component is arranged and which is assigned a resistance device, the method comprising:

determining sensor data via at least one sensor during use of the orthotic or prosthetic knee joint;

changing a flexion resistance R in accordance with the sensor data;

determining a linear acceleration a_F of the below-knee component;

comparing the determined linear acceleration a_F with at least one threshold value;

changing the flexion resistance R if the threshold value is reached;

wherein, after a reduction of the flexion resistance R, the method further comprises increasing the flexion resistance R again if, within a predefined time interval, no bending of the knee joint took place, or if, within an enclosed knee angle φ

_K, a limit value for an acceleration is exceeded.

2. The method as claimed in claim 1, further comprising determining an extended stride position of a prosthesis or orthosis having the artificial prosthetic or orthotic knee joint, and reducing the flexion resistance R when the extended stride position is present.

3. The method as claimed in claim 1 further comprising determining an absolute angle φ

_US of the below-knee component in order to detect a terminal stance phase, and reducing the flexion resistance R if a predefined limit value for the absolute angle φ

_US of the below-knee component is exceeded.

4. The method as claimed in claim 3, further comprising measuring the absolute angle φ

_US of the below-knee component from an absolute angle of a thigh component and a knee angle φ

_K or directly with an inertial angle sensor.

5. The method as claimed in claim 1, further comprising determining a knee angle φ

_K via a knee angle sensor, and reducing the flexion resistance R if a predefined limit value for the knee angle φ

_K is not reached.

6. The method as claimed in claim 1, further comprising determining a knee angle velocity ω

_K, and reducing the flexion resistance R only when a limit value is exceeded.

7. The method as claimed in claim 1, further comprising calculating or detecting an angular velocity ω

_US of the below-knee component via a sensor, and reducing the flexion resistance R only when the angular velocity ω

_US is below a limit value.

8. The method as claimed in claim 1, further comprising using the linear acceleration a_F of the below-knee component at the sole level as a basis for the control.

9. The method as claimed in claim 1, further comprising reducing the flexion resistance R when there is a hyperextension of the below-knee component.

10. The method as claimed in claim 1, wherein the knee joint has an elastic extension stop, the method further comprising:

calculating a knee moment via the knee angle φ

_K;

calculating a spring characteristic of the extension stop;

reducing the flexion resistance R if a knee moment in the extension direction exceeds a threshold value.

11. The method as claimed in claim 1, further comprising calculating or detecting a rotation direction of the below-knee component via a sensor, and reducing the flexion resistance R only if there is a forward rotation.

12. The method as claimed in claim 1, further comprising determining acceleration data of the below-knee component via at least one of an acceleration sensor and an inertial angle sensor.

13. A method for controlling an artificial orthotic or prosthetic knee joint, the orthotic or prosthetic knee joint including a resistance device, the method comprising:

providing at least one sensor and a below-knee component positioned on the orthotic or prosthetic knee joint;

determining sensor data via the at least one sensor during use of the orthotic or prosthetic knee joint;

changing a flexion resistance applied by the resistance device using the sensor data;

determining a linear acceleration of the below-knee component with the sensor data;

comparing the determined linear acceleration with at least one threshold value;

changing the flexion resistance if the threshold value is reached;

using the linear acceleration of the below-knee component at the sole level as a basis for the control;

wherein, after a reduction of the flexion resistance, the method further comprising increasing the flexion resistance again if, within a predefined time interval, no bending of the knee joint took place, or if, within an enclosed knee angle, a limit value for an acceleration is exceeded.

14. The method as claimed in claim 13, further comprising determining an extended stride position of a prosthesis or orthosis having the artificial prosthetic or orthotic knee joint, and reducing the flexion resistance when the extended stride position is present.

15. The method as claimed in claim 13, further comprising determining an absolute angle of the below-knee component in order to detect a terminal stance phase, and reducing the flexion resistance if a predefined limit value for the absolute angle of the below-knee component is exceeded.

16. The method as claimed in claim 15, further comprising measuring the absolute angle of the below-knee component from an absolute angle of a thigh component and a knee angle or directly with an inertial angle sensor.

17. The method as claimed in claim 13, further comprising determining a knee angle via the at least one sensor, and reducing the flexion resistance if a predefined limit value for the knee angle is not reached.

18. The method as claimed in claim 13, further comprising determining a knee angle velocity, and reducing the flexion resistance only when a limit value is exceeded.

19. The method as claimed in claim 13, further comprising calculating or detecting an angular velocity of the below-knee component via the at least one sensor, and reducing the flexion resistance only when the angular velocity is below a limit value.