Prosthetic knee with swing assist

Patent metadata

Field	Value
Publication number	US-11883304-B2
Application number	US-202218046447-A
Country	US
Kind code	B2
Filing date	Oct 13, 2022
Priority date	Jan 25, 2018
Publication date	Jan 30, 2024
Grant date	Jan 30, 2024

Abstract

The present disclosure provides for a device and method of control for an artificial prosthetic knee. A prosthetic knee according to the present disclosure relies on strictly passive means of providing support during weight bearing and supplements a resistive swing-phase mechanism with a small powered actuator. This actuator adds power to the knee, exclusively during swing phase, to improve swing-phase behavior. In particular, the knee still relies on the resistive swing-phase mechanism to provide nominal swing-phase knee motion, but supplements that motion as needed with the small powered actuator.

First claim

What is claimed is:

1. A knee prosthesis, comprising:
a shank link;
a polycentric knee joint comprising an extension stop, the extension stop substantially preventing the knee prosthesis from hyperextending;
a thigh link rotatably coupled to the shank link by the polycentric knee joint;
at least one powered control element configured to power rotation of the thigh link relative to the shank link; at least one sensor;
and a controller coupled to the at least one sensor, the controller configured to:
receive sensor measurements from the at least one sensor and determine, based at least on the sensor measurements, a present state of a plurality of states comprising at least a swing state and a stance state; and
cause the at least one powered control element to power rotation if the present state is a swing state;

wherein the polycentric knee joint is further configured to provide a center of rotation of the thigh link relative to the shank link, wherein the center of rotation is substantially posterior to a ground reaction force vector if the present state is the stance state, and
wherein the at least one powered control element is configured to apply a maximum torque on the knee prosthesis which is substantially smaller than a maximum torque provided by the polycentric knee joint when the polycentric knee joint is hyperextended.

2. The knee prosthesis of claim 1 , wherein the at least one powered control element comprises an electric motor coupled to the thigh link and the shank link through a power screw.

3. The knee prosthesis of claim 2 , where the power screw is a backdrivable power screw.

4. The knee prosthesis of claim 1 , wherein the at least one powered control element comprises a linear motor drive system configured for power-assisted swing motion assist.

5. The knee prosthesis of claim 1 , wherein the at least one powered control element comprises an electric motor coupled rotatably to one of the polycentric mechanism links.

6. The knee prosthesis of claim 1 , wherein the polycentric knee joint is a 4-bar knee joint.

7. The knee prosthesis of claim 4 , wherein the polycentric knee joint is a 4-bar knee joint, and wherein the polycentric knee and the linear motor drive system comprise a single degree-of-freedom 6-bar mechanism.

8. A knee prosthesis, comprising:
a shank link;
a polycentric knee joint comprising an extension stop, the extension stop substantially preventing the knee prosthesis from hyperextending;
a thigh link rotatably coupled to the shank link by the polycentric knee joint;
at least one powered control element configured to power rotation of the thigh link relative to the shank link;
at least one sensor; and
a controller coupled to the at least one sensor, the controller configured to:
receive sensor measurements from the at least one sensor and determine, based at least on the sensor measurements, a present state of a plurality of states comprising at least a swing state and a stance state; and
cause the at least one powered control element to power rotation if the present state is a swing state;

wherein the polycentric knee joint is further configured to provide a center of rotation of the thigh link relative to the shank link, wherein the center of rotation is substantially posterior to a ground reaction force vector if the present state is the stance state, and
a plurality of revolute connecting links and a plurality of prismatic connecting links.

9. A knee prosthesis, comprising:
a shank link;
a polycentric knee joint comprising an extension stop, the extension stop substantially preventing the knee prosthesis from hyperextending;
a thigh link rotatably coupled to the shank link by the polycentric knee joint;
at least one powered control element configured to power rotation of the thigh link relative to the shank link; at least one sensor; and
a controller coupled to the at least one sensor, the controller configured to:
receive sensor measurements from the at least one sensor and determine, based at least on the sensor measurements, a present state of a plurality of states comprising at least a swing state and a stance state; and
cause the at least one powered control element to power rotation if the present state is a swing state;

wherein the polycentric knee joint is further configured to provide a center of rotation of the thigh link relative to the shank link, wherein the center of rotation is substantially posterior to a ground reaction force vector if the present state is the stance state,
where the at least one powered control element powers rotation exclusively in the swing state.

Assignees

• Univ Vanderbilt

Inventors

• Goldfarb Michael
• Baimyshev Almaskhan
• Bartlett Harrison
• Lee Jantzen

Classifications

• A61F2/644 Primary

  of the single-bar or multi-bar linkage type · CPC title

• A61F2/70

  electrical · CPC title

• A61F2/74

  fluid {, i.e. hydraulic or pneumatic} · CPC title

• A61F2/741

  using powered actuators, e.g. stepper motors or solenoids · CPC title

• A61F2/748

  Valve systems · CPC title