Control of a passive prosthetic knee joint with adjustable damping

1. A method for initiating and implementing a stair-climbing mode in a passive prosthetic knee joint connected to a prosthetic leg unit including a prosthetic foot, the method comprising:

detecting with at least one sensor of the passive prosthetic knee joint a lift phase of the prosthetic foot, the at least one sensor generating sensor data;

reducing a flexion damping level of the passive prosthetic knee joint in the lift phase in response to the sensor data to a level below that which is used by the passive prosthetic knee joint for walking on level ground;

detecting a lowering phase of the prosthetic foot;

increasing the flexion damping level of the passive prosthetic knee joint in the lowering phase to a level above that which is used for walking on level ground;

maintaining the flexion damping level until a straightened hip is detected when in the lowering phase.

2. The method of claim 1 , wherein in the lowering phase, an extension damping level is increased to a level above that which is used for walking on level ground.

3. The method of claim 1 , further comprising the step of, in the lowering phase, detecting a knee angle and establishing the flexion damping level as a function of the detected knee angle.

4. A method of controlling a passive prosthetic knee joint with adjustable damping in the direction of flexion such that a prosthetic unit that is connected to the passive prosthetic knee joint, and that includes an artificial foot, can climb stairs, the method comprising:

detecting with at least one sensor of the passive prosthetic knee joint a low-torque lift of the prosthetic foot, the at least one sensor generating sensor data, and

lowering the flexion damping in a lift phase in response to the sensor data to below a level that is used for walking on level ground;

increasing extension damping and flexion damping in a foot placement and hip-straightening phase to a level above a damping of a swing phase control when walking on level ground;

maintaining the flexion damping in the foot placement and hip-straightening phase until a hip is fully straightened.

5. The method of claim 4 , wherein the flexion damping in the foot placement phase is increased to a maximum value.

6. The method of claim 4 , wherein the flexion damping is increased as a function of the change of the knee angle after lowering the flexion damping in the lift phase to a level that is used for walking on level ground.

7. The method of claim 4 , wherein the flexion damping is lowered as a function of an axial force acting on the lower leg shaft.

8. The method of claim 4 , wherein an extension damping is set during the lift phase and also during the foot placement and hip-straightening phase.

9. The method of claim 4 , wherein the at least one sensor includes a force sensor or a torque sensor.

10. The method of claim 4 , wherein the low-torque lift is detected by measuring a horizontal acceleration of the prosthetic foot and by recording a bending in the passive prosthetic knee joint.

11. The method of claim 4 , wherein the low-torque lift is detected by the at least one sensor determining a torque at the front of the prosthetic foot.

12. The method of claim 4 , wherein the flexion in the lift phase is provided by a pre-tensioned spring mechanism.

13. The method of claim 4 , wherein the increase in the flexion and extension damping is initiated when the prosthetic foot, after being lifted, is placed down again.

14. The method of claim 13 , wherein the foot placement is detected by an axial force measurement in the lower leg shaft or in the prosthetic foot.

15. The method of claim 4 , wherein the flexion damping in the lift phase is lowered to a minimum value.

16. The method of claim 4 , wherein after the flexion damping has been lowered, a free extension is set with time control.

17. The method of claim 16 , wherein the free extension is spring-assisted.

18. The method of claim 16 , wherein the time control is effected mechanically or electronically.

19. The method of claim 4 , wherein the flexion damping is increased as a function of an axial force acting on the lower leg shaft after lowering the flexion damping in the lift phase to a level that is used for walking on level ground.

20. A method for initiating and implementing a stair-climbing mode in a passive prosthetic knee joint connected to a prosthetic leg unit including a prosthetic foot, the method comprising:

detecting with at least one sensor a lift phase of the prosthetic foot, the at least one sensor generating sensor data;

reducing a flexion damping level of the knee joint in the lift phase in response to the sensor data to a level below that which is used by the knee joint for walking on level ground;

detecting a lowering phase of the prosthetic foot;

increasing the flexion damping level of the knee joint in the lowering phase to a level above that which is used for walking on level ground;

detecting a knee angle and establishing the flexion damping level as a function of the detected knee angle when in the lowering phase.

21. A method of controlling a passive prosthetic knee joint with adjustable damping in the direction of flexion such that a prosthetic unit that is connected to the prosthetic knee joint, and that includes an artificial foot, can climb stairs, the method comprising:

detecting with at least one sensor a low-torque lift of the prosthetic foot, the at least one sensor generating sensor data;

lowering the flexion damping in a lift phase in response to the sensor data to below a level that is used for walking on level ground;

increasing the flexion damping as a function of the change of the knee angle after lowering the flexion damping in the lift phase to a level that is used for walking on level ground.

22. A method of controlling a passive prosthetic knee joint with adjustable damping in the direction of flexion such that a prosthetic unit that is connected to the prosthetic knee joint, and that includes an artificial foot, can climb stairs, the method comprising:

detecting with at least one sensor a low-torque lift of the prosthetic foot, the at least one sensor generating sensor data;

lowering the flexion damping in a lift phase in response to the sensor data to below a level that is used for walking on level ground;

wherein the low-torque lift is detected by measuring a horizontal acceleration of the prosthetic foot and by recording a bending in the prosthetic knee joint.

23. A method of controlling a passive prosthetic knee joint with adjustable damping in the direction of flexion such that a prosthetic unit that is connected to the prosthetic knee joint, and that includes an artificial foot, can climb stairs, the method comprising:

detecting with at least one sensor a low-torque lift of the prosthetic foot, the at least one sensor generating sensor data;

lowering the flexion damping in a lift phase in response to the sensor data to below a level that is used for walking on level ground;

setting a free extension with time control after the flexion damping has been lowered.

24. A method of controlling a passive prosthetic knee joint with adjustable damping in the direction of flexion such that a prosthetic unit that is connected to the prosthetic knee joint, and that includes an artificial foot, can climb stairs, the method comprising:

detecting with at least one sensor a low-torque lift of the prosthetic foot, the at least one sensor generating sensor data;

lowering the flexion damping in a lift phase in response to the sensor data to below a level that is used for walking on level ground;

increasing the flexion damping as a function of an axial force acting on the lower leg shaft after lowering the flexion damping in the lift phase to a level that is used for walking on level ground.

25. A method of controlling a passive prosthetic knee joint with adjustable damping in the direction of flexion such that a prosthetic unit that is connected to the passive prosthetic knee joint, and that includes an artificial foot, can climb stairs, the method comprising:

detecting with at least one sensor of the passive prosthetic knee joint a low-torque lift of the prosthetic foot, the at least one sensor generating sensor data, and

lowering the flexion damping in a lift phase in response to the sensor data to below a level that is used for walking on level ground;

increasing extension damping and flexion damping in a foot placement and hip-straightening phase to a level above a damping of a swing phase control when walking on level ground;

wherein increasing the flexion damping and extension damping is initiated when the prosthetic foot, after being lifted, is placed down again;

detecting the foot placement by an axial force measurement in a lower leg shaft or in the artificial foot.