Method for design and manufacture of compliant prosthetic foot

Patent metadata

Field	Value
Publication number	US-12090067-B2
Application number	US-202318305005-A
Country	US
Kind code	B2
Filing date	Apr 21, 2023
Priority date	May 26, 2017
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

A compliant prosthetic foot is designed and fabricated by combining a compliant mechanism optimization technique with a calculation of low leg trajectory error under a reference loading condition. The compliant mechanism optimization technique includes a set of determinants for the compliant prosthetic foot. An optimized set of determinants of the compliant prosthetic foot is formed that minimizes the lower leg trajectory error relative to a target kinematic data set. The compliant prosthetic foot is then fabricated in conformance with the optimized set of determinants.

First claim

What is claimed is:

1. A compliant prosthetic foot, comprising:
a keel; and
a forefoot, a shape of the keel and forefoot defined by a set of determinants for a parametric curve, the determinants iterated to minimize a lower leg trajectory error relative to a target kinematic data set.

2. The compliant prosthetic foot of claim 1 , wherein the keel and the forefoot is a singular body.

3. The compliant prosthetic foot of claim 2 , wherein the singular body is compliant along its entire length.

4. The compliant prosthetic foot of claim 1 , wherein the target kinematic data set includes a physiological data set.

5. The compliant prosthetic foot of claim 1 , wherein the set of determinates comprises wide Bezier curve parameters.

6. The compliant prosthetic foot of claim 5 , wherein the parametric curve is a cubic curve defined by relative positions of at least two control points.

7. The compliant prosthetic foot of claim 6 , wherein the cubic curve is defined by relative positions of at least four control points.

8. The compliant prosthetic foot of claim 5 , wherein the set of determinants comprises a width of the Bezier curve as a variable, wherein the width is a function of control circles.

9. The compliant prosthetic foot of claim 8 , wherein the width of the Bezier curve is defined as a function of diameters of at least four control circles.

10. The compliant prosthetic foot of claim 1 , wherein the set of determinants of the compliant prosthetic foot is set by finite element analysis.

11. The compliant prosthetic foot of claim 10 , wherein the finite element analysis is conducted for each of a set time intervals within a gait cycle.

12. The compliant prosthetic foot of claim 11 , wherein the time intervals extend from foot flat.

13. The compliant prosthetic foot of claim 12 , further comprising a heel component in combination with a wide Bezier curve.

14. The compliant prosthetic foot of claim 13 , wherein the time intervals extend from early stance plantar flexion.

15. The compliant prosthetic foot of claim 10 , wherein the set of determinants comprises material properties of the keel and forefoot.

16. The compliant prosthetic foot of claim 1 , wherein the target kinematic data set is a physiological data set obtained from a subject for whom the compliant prosthetic foot is being fabricated.

17. The compliant prosthetic foot of claim 1 , wherein the target kinematic data set is a physiological data set obtained from an able-bodied subject with the same body size and mass as the subject for whom the compliant prosthetic foot is being fabricated.

18. The compliant prosthetic foot of claim 1 , wherein the target kinematic data set is a physiological data set scaled from an able-bodied subject to adjust for differences in body size and mass compared to the subject for whom the compliant prosthetic foot is being fabricated.

19. The compliant prosthetic foot of claim 1 , wherein the target kinematic data set is obtained by at least one member of the group consisting of simulation, measurement of a subject, measurement from a population of subjects, and scaling in magnitude from a subject(s) of a different body size and weight.

20. The compliant prosthetic foot of claim 1 , wherein the compliant prosthetic foot is fabricated by at least one method selected from the group consisting of: machining; three-dimensional printing; a layup method; a water jet method; additive fabrication; subtractive fabrication; lamination; composite manufacture; injection molding; carbon fiber fabrication; extrusion; casting; molding; co-molding; carving; and vulcanization.

21. The compliant prosthetic foot of claim 1 , wherein the compliant prosthetic foot is fabricated of at least one member of the group consisting of: nylon 6/6; carbon fiber; fiber glass; spring steel; titanium; plastic; an alloy of metals; a polymer; a composite; a resin; a thermoplastic; laminate; a rubber; an elastomer; a non-viscoelastic material; a viscoelastic material; and wood.

Assignees

• Massachusetts Inst Technology

Inventors

• Winter V Amos Greene
• Olesnavage Kathryn Michelle

Classifications

• G05B2219/49023

  3-D printing, layer of powder, add drops of binder in layer, new powder · CPC title

• G05B19/4099

  Surface or curve machining, making three-dimensional [3D] objects, e.g. desktop manufacturing · CPC title

• A61F2002/6657

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

• A61F2002/505

  using CAD-CAM techniques or NC-techniques · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title