Passive power-conservative artificial knee

Patent metadata

Field	Value
Publication number	US-2016374887-A1
Application number	US-201615190946-A
Country	US
Kind code	A1
Filing date	Jun 23, 2016
Priority date	Jun 23, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

A passive artificial knee comprises first and second links rotatably coupled at a knee joint, a passive compressive force generator rotatably coupled to the second link, and a release mechanism coupled to the first link. When a relative angle of the first and second links is less than a toggle angle, the release mechanism locks in a first operational mode, and the force generator compresses, resisting the flexing of the second link relative to the first link. When the relative angle is larger than the toggle angle, the force generator decompresses and encourages the flexion of said second link relative to said first link. When the force generator is substantially extended and said compressive force is substantially small, the release mechanism moves into a second operational mode, wherein the force generator neither resists nor encourages the extension and flexion of said second link from said first link.

First claim

What is claimed is:

1 . A passive power-conservative artificial knee comprising:
a first link; a second link rotatably coupled to said first link at a knee joint; a passive compressive force generator rotatably coupled to said second link from a first end of the compression force generator, and capable of generating a compressive force between said first end and a second end of the compression force generator; a release mechanism coupled to said first link, wherein said release mechanism has at least a first operational mode and a second operational mode, wherein in the first operational mode said release mechanism couples the second end of said compression force generator to said first link and in the second operational mode said release mechanism does not couple said second end of said compression force generator to said first link, wherein: when said second link is flexing toward said first link and an angle of said second link relative to said first link is less than a toggle angle, said release mechanism moves into the first operational mode where said compression force generator is becoming compressed, locks said release mechanism in the first operational mode, and resists the flexing of said second link relative to said first link; when said second link is flexing toward said first link and the angle of said second link relative to said first link is larger than said toggle angle, said release mechanism remains in the first operational mode and said compressive force generator is becoming decompressed and therefore encourages the flexion of said second link relative to said first link; when said compression force generator is substantially extended and said compressive force is substantially small, said release mechanism moves into the second operational mode; and when said release mechanism is in said second operational mode, said compression force generator neither resists nor encourages the extension and flexion of said second link from said first link.

2 . The passive power-conservative artificial knee of claim 1 , wherein said first link is configurable to move in unison with a user's thigh and said second link is configurable to move in unison with a user's shank.

3 . The exoskeleton of claim 1 , wherein said first link is configurable to move in unison with a user's shank and said second link is configurable to move in unison with a user's thigh.

4 . The exoskeleton of claim 1 , wherein said first link comprises a first connector to couple said first link to a user's shank and said second link includes a second connector to couple said second link to a user's thigh.

5 . The exoskeleton of claim 1 , wherein said first link comprises a first connector to couple the first link to a user's thigh and said second link includes a second connector to couple the second link to a user's shank.

6 . The passive power-conservative artificial knee of claim 1 , wherein said release mechanism comprises:
a holding block rotatably coupled to said first link; a constraint path in said holding block allowing for motion of said second end of said force generator along the constraint path in the holding block; a moving block capable of blocking the motion of said second end of said force generator in said holding block; and a trigger spring coupled to said moving block from a first end of the trigger spring and to said first link from a second end of the trigger spring, wherein; when said release mechanism is in the first operational mode, said moving block is held stationary in its slot by a force of said force generator while said trigger spring is pulled by its second end imposing a tensile force on said moving block; when said release mechanism is in the second operational mode, said moving block and said trigger spring move due to motion of said second link relative to said first link, and said moving block is not blocking the motion of the second end of said force generator.

7 . The passive power-conservative artificial knee of claim 6 , wherein:
said second end of said trigger spring is coupled to a guiding piece which moves in a cam slot on the first link; when the release mechanism is in the first operational mode and the second link flexes, said guiding piece moves along said cam slot, thereby increasing the tensile force; and when said release mechanism is in the second operational mode if said second link extends relative to said first link, said guiding piece moves along said cam slot, thereby pushing said moving block.

8 . The passive power-conservative artificial knee of claim 1 , wherein said release mechanism comprises:
a hook rotatably coupled to said second link; a constraint path in said second link allowing for motion of said second end of said force generator along said constraint path; a trigger spring coupled to said hook from a first end of the trigger spring and coupled to said force generator from a second end of the trigger spring; and a return spring coupled to said hook from a first end of the return spring and coupled to said second link from a second end of the return spring, wherein: when said release mechanism is in the first operational mode, said hook is held stationary by a friction force applied by the force generator, while said trigger spring is pulled by its second end, thus imposing a tensile force on said hook; and when said release mechanism is in the second operational mode, said hook is moved by the tensile force of the trigger spring such that said hook is not blocking the motion of the second end of said force generator.

9 . The passive power-conservative artificial knee of claim 1 , further comprising an ankle-foot orthosis capable of being coupled to a user's foot.

10 . The passive power-conservative artificial knee of claim 9 , wherein said ankle-foot orthosis is connectable to said first link or said second link.

11 . The passive power-conservative artificial knee of claim 9 , wherein said ankle-foot-orthosis comprises an internal or external ankle-foot-orthosis or combination of internal and external ankle-foot-orthoses selected from the group consisting of rigid AFO, complaint AFO, hinged AFO, non-hinged AFO, Plantarflexion Stop AFO, standard posterior leaf spring AFO, energy return AFO, flexible AFO, rigid AFO, AFO with tamarack flexure, AFO with anti-talus, AFO anti-talus (anterior shell or shell in the front), AFO with a free-motion ankle joint, AFO with an adjustable rigid ankle joint, AFO with a spring-loaded ankle joint, and AFO with an adjustable spring-loaded ankle joint.

12 . The passive power-conservative artificial knee of claim 1 , further comprising an exoskeleton trunk configurable to be coupled to said user's upper body, said exoskeleton trunk including:
a torso link capable of being coupled to a user's torso; and a trunk thigh link configurable to be rotatably coupled to said torso link.

13 . The passive power-conservative artificial knee of claim 12 , wherein said trunk thigh link is coupled to a link selected from a set consisting of said first link and said second link.

14 . The passive power-conservative artificial knee of claim 12 , further comprising an actuator capable of providing torque between said torso link and said trunk thigh link.

15 . The passive power-conservative artificial knee of claim 12 , further comprising an ankle-foot orthosis capable of being coupled to a user's foot.

16 . The exoskeleton of claim 15 , wherein said ankle-foot orthosis is coupled to a link selected from a set consisting of said first link and said second link.

17 . T

Assignees

• Univ California

Inventors

• Wu Shang-Li
• Kazerooni Homayoon

Classifications

• A61H1/0244

  Hip (A61H1/0255 takes precedence) · CPC title

• A61H2201/1676

  Pivoting · CPC title

• A61F5/0127

  for the feet (A61F5/0111 takes precedence) · CPC title

• A61H2201/165

  Wearable interfaces · CPC title

• A61H3/00 Primary

  Appliances for aiding patients or disabled persons to walk about (apparatus for helping babies to walk A47D13/04 {; applying electrical currents by contact electrodes for stimulating motor muscles, e.g. walking assistance A61N1/36003}) · CPC title