Leg prosthesis with an artificial knee joint provided with an adjustment device

• US 6,423,098 B1
• Filed: 08/09/1999
• Issued: 07/23/2002
• Est. Priority Date: 12/10/1997
• Status: Expired due to Term

• Current Assignee: Otto Bock Healthcare Products GmbH (Albatros Son Holding BV)
• Original Assignee: Biedermann Motech GmbH
• Inventors: Biedermann, Lutz
• Primary Examiner(s): Willse, David H.
• Application Number:
  US09/367,198
• Time in Patent Office: 1,079 Days
• Field of Search: 623/24-27, 623/39, 623/43-46, 623/57, 623/58
• US Class Current: 623/24
• CPC Class Codes: A61F 2/64 Knee joints
• CPC Class Codes: A61F 2/70 electrical
• 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 2002/5003 having damping means, e.g. shock absorbers
• CPC Class Codes: A61F 2002/607 Lower legs
• CPC Class Codes: A61F 2002/6614 Feet
• CPC Class Codes: A61F 2002/6818 for braking
• CPC Class Codes: A61F 2002/6863 magnetic
• CPC Class Codes: A61F 2002/704 computer-controlled, e.g. robotic control
• CPC Class Codes: A61F 2002/7635 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61F 2210/009 magnetic

Abstract

A leg prosthesis having an artificial knee joint with swing phase control and recoil break comprises a damping member acting upon the knee joint, detectors for detecting force, knee angle and acceleration and a control unit for controlling the dampening degree of the damping member on the basis of the detected values. The damping characteristics of the damping member are varied in dependence on control signals produced by the control unit on the basis of a viscosity change of the magneto-rheological liquid.

Claims

1. A leg prosthesis having an artificial knee joint with swing phase control and recoil brake, said prosthesis comprising:

means for producing control signals for controlling said knee joint; and

a control member controlling said knee joint on the basis of said control signals;

said control member comprising a damping member in the form of a piston cylinder device having a piston and a cylinder filled with a magneto-rheological liquid and means for changing the viscosity of said magneto-rheological liquid within the cylinder on the basis of said control signals, wherein a damping effect is provided by the piston in the cylinder.

2. The leg prosthesis of claim 1, said means for producing control signals comprising a detector provided at said leg prosthesis,

said detector including (A) a detector selected from the group consisting of (1) a force detector, (2) a knee angle detector or (3) an acceleration detector having a signal output, and (B) a control unit connected to said signal output of said detector for producing said control signals on the basis of the values of force, knee angle or acceleration detected by said detector.

3. The leg prosthesis of claim 2 comprising a detector selected from the group consisting of:

(1) a detector provided at the knee joint for detecting the knee angle,

(2) a detector provided in the region of a shin for detecting a lateral or forward acceleration, or

(3) a force detector provided at the sole.

4. The leg prosthesis of claim 2, further comprising a regulating unit for automatic regulation of the knee joint functions during the walking on the basis of the actually detected values of force, acceleration or knee angle, said regulation unit comprising said knee joint, said control unit and said control member.

5. The leg prosthesis of claim 2, wherein said control unit is mounted to said leg prosthesis and fixedly connected to said control member.

6. The leg prosthesis of claim 1, wherein said means for changing the viscosity of said magneto-rheological liquid is a solenoid, and said control member controls said solenoid for varying the magnetic field produced by said solenoid on the basis of said control signals.

7. A leg prosthesis according to claim 1, said leg prosthesis further comprising:

at least one detector provided at said prosthesis for detection of force, knee angle or acceleration, said detector having a signal output; and

a control unit connected to said signal output for producing control signals on the basis of the values detected by said detector;

wherein said control member is provided at said knee joint for automatically controlling said knee joint on the basis of said control signals during operation of said prosthesis.

8. The leg prosthesis of claim 1, wherein said piston-cylinder device comprises an axially displaceable piston or a rotary piston.

9. A leg prosthesis having an artificial knee joint with swing phase control and recoil brake, said prosthesis comprising:

means for producing control signals for controlling said knee joint;

at least one detector provided at said prosthesis for detection of force, knee angle or acceleration, said detector having a signal output;

a control unit connected to said signal output for producing control signals on the basis of the values detected by said detector; and

a control member provided at said knee joint for automatically controlling said knee joint on the basis of said control signals during operation of said prosthesis;

said control member comprising a piston and a cylinder filled with a magneto-rheological liquid and means for changing the viscosity of said magneto-rheological liquid on the basis of said control signals, wherein said magneto-rheological liquid provides resistance within the cylinder, thereby providing a damping effect on the piston.