Foot prosthesis

Patent metadata

Field	Value
Publication number	US-10758376-B2
Application number	US-201615570232-A
Country	US
Kind code	B2
Filing date	Apr 27, 2016
Priority date	Apr 29, 2015
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

A foot prosthesis having a lower-leg connection part, a foot part, a connecting element with a joint function which connects the lower-leg connection part to the foot part, and a release device, which controls movement of the foot part in relation to the lower-leg connection part. The release device includes an inhibiting device that is designed in such a way that a dorsal extension motion of the foot part in relation to the lower-leg connection part in an angular range from a maximal plantar flexion position to a zero position is inhibited less intensely than a dorsal extension motion of the foot part from the zero position.

First claim

The invention claimed is:

1. A foot prosthesis, comprising:
a lower-leg connection part;
a foot part;
a connecting element with a joint that connects the lower-leg connection part with the foot part;
a release device operable to inhibit and disinhibit a motion of the foot part relative to the lower-leg connection part, the release device comprising a passive inhibiting device that is designed in such a way that a dorsal extension motion of the foot part in relation to the lower-leg connection part in an angular range from a maximal plantar flexion position to a zero position is inhibited less intensely than a dorsal extension motion of the foot part from the zero position;
wherein the release device is designed in such a way that it only releases the dorsal extension motion of the foot part beyond the zero position if an ankle torque acting on the foot part lies above a predetermined release threshold value.

2. The foot prosthesis according to claim 1 , wherein the release device is designed in such a way that the zero position can be adjusted.

3. The foot prosthesis according to claim 1 , wherein
the release device has a hydraulic cylinder that is connected to the foot part and the lower-leg connection part, and
the inhibiting device is a hydraulic device that is connected in fluid communication with the hydraulic cylinder such that a dorsal extension motion of the foot part in relation to the lower-leg connection part in an angular range from a maximal plantar flexion position to a zero position is inhibited less intensely than a dorsal extension motion of the foot part from the zero position.

4. The foot prosthesis according claim 3 , wherein the inhibiting device comprises:
a first fluid line through which the hydraulic fluid flows when the foot part executes a dorsal extension motion beyond the zero position, the first fluid line having a first flow resistance;
a bypass line through which the hydraulic fluid flows when the foot part executes a dorsal extension motion between the maximal plantar flexion position and the zero position,
the bypass line having a bypass flow resistance that is smaller than the first flow resistance.

5. The foot prosthesis according to claim 4 , wherein the first fluid line comprises a check valve, the check valve arranged to:
prevent a dorsal extension motion beyond the zero position, provided that an ankle torque acting on the foot part does not lie above a release threshold value, and
release a dorsal extension motion beyond the zero position if the ankle torque lies above the release threshold value.

6. The foot prosthesis according to claim 4 , wherein the inhibiting device has a second fluid line through which the hydraulic fluid flows when the foot part executes a plantar flexion motion, and the second fluid line has a second flow resistance that is smaller than the first flow resistance.

7. The foot prosthesis according to claim 4 , wherein the release device comprises a second hydraulic cylinder, which is connected to the inhibiting device in such a way that:
a dorsal extension motion beyond the zero position causes the hydraulic fluid to flow out of the second hydraulic cylinder, through the first fluid line, and into the first hydraulic cylinder;
a dorsal extension motion between the maximal plantar flexion position and the zero position causes the hydraulic fluid to flow out of the second hydraulic cylinder, through the bypass line, and into the first hydraulic cylinder;
a plantar flexion motion causes the hydraulic fluid to flow out of the second hydraulic cylinder, through the first fluid line, and into the first hydraulic cylinder.

8. The foot prosthesis according to claim 7 , wherein the bypass line is connected to the first hydraulic cylinder or the second hydraulic cylinder such that a tapping point of a tap opening along a longitudinal axis of the hydraulic cylinder can be changed to set the zero position.

9. The foot prosthesis according to claim 4 , wherein the hydraulic cylinder is configured to be dual-acting and is connected to the inhibiting device in such a way that:
a dorsal extension motion beyond the zero position causes the hydraulic fluid to flow out of an outlet opening, which is arranged at an outlet end of the hydraulic cylinder, through the first fluid line and back into the first hydraulic cylinder;
a dorsal extension motion between the maximal plantar flexion position and the zero position causes the hydraulic fluid to flow through a tap opening and the bypass line;
a plantar flexion motion causes the hydraulic fluid to flow through a second fluid line or the bypass line.

10. The foot prosthesis according to claim 3 , wherein the cylinder is a linear cylinder.

11. The foot prosthesis according to claim 1 , wherein the release device comprises:
a friction brake;
a mechanical return element arranged such that a dorsal extension motion of the foot part is braked more intensely than a plantar flexion motion.

12. A foot prosthesis, comprising:
a lower-leg connection part;
a foot part;
a connecting element that connects the lower-leg connection part with the foot part;
a release device to control movement of the foot part relative to the lower-leg connection part, the release device having a passive inhibiting device to inhibit a dorsal extension motion of the foot part relative to the lower-leg connection part in an angular range from a maximal plantar flexion position to a zero position less intensely than a dorsal extension motion of the foot part from the zero position, and the release device releases the dorsal extension motion of the foot part beyond the zero position only if an ankle torque acting on the foot part is above a predetermined release threshold value.

13. The foot prosthesis according to claim 12 , wherein the release device has an adjustable zero position.

14. The foot prosthesis according to claim 12 , wherein the release device has a hydraulic cylinder that is connected to the foot part and the lower-leg connection part, and the inhibiting device is a hydraulic device that is connected in fluid communication with the hydraulic cylinder to inhibit a dorsal extension motion of the foot part in relation to the lower-leg connection part in an angular range from a maximal plantar flexion position to a zero position less intensely than a dorsal extension motion of the foot part from the zero position.

15. The foot prosthesis according claim 14 , wherein the inhibiting device comprises:
a first fluid line through which the hydraulic fluid flows when the foot part executes a dorsal extension motion beyond the zero position, the first fluid line having a first flow resistance;
a bypass line through which the hydraulic fluid flows when the foot part executes a dorsal extension motion between the maximal plantar flexion position and the zero position, the bypass line having a bypass flow resistance that is smaller than the first flow resistance.

16. The foot prosthesis according to claim 15 , wherein the first fluid line comprises a check valve, the check valve to prevent a dorsal extension motion beyond the zero position, provided that an ankle torque acting on the foot part does not lie above a release threshold value, and release a dorsal extension motion beyond the zero position if the ankle torque lies above the release threshold value.

17. The foot prosthesis according to claim 15 , wherein the inhibiting device has a second fluid line through which the hydraulic fluid flows when the foot part executes a plantar flexion motion, and the second fluid line has a second

Assignees

• Bock Healthcare Gmbh
• Ottobock Se & Co Kgaa

Inventors

• Kaltenborn Sven
• Gehrmann Georg
• Schwartz Miclas

Classifications

• A61F2/748

  Valve systems · CPC title

• A61F2/74

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

• A61F2/66 Primary

  Feet; Ankle joints · CPC title

• A61B5/112

  Gait analysis · CPC title

• A61F2002/6657

  having a plate-like or strip-like spring element, e.g. an energy-storing cantilever spring keel · CPC title