Prosthetic ankle assembly and ankle-foot system comprising same
Inventors
Hansen, Andrew • Voss, Gregory Owen • Nickel, Eric • Hein, Emily
Assignees
US Department of Veterans Affairs
Publication Number
US-12070399-B2
Publication Date
2024-08-27
Expiration Date
2039-06-17
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Abstract
Disclosed herein are devices, systems, and methods for accommodating quick and easy exchange of footwear for lower limb amputees. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.
Core Innovation
The invention relates to ankle-foot prosthetic devices that allow quick and easy exchange of footwear having different heel heights. Specifically, disclosed are ankle assemblies comprising a resilient joint subassembly and an endoskeletal connector configured for at least partial receipt within a receptacle defined by a prosthetic foot. The resilient joint subassembly permits pivotal movement of the endoskeletal connector about a transverse pivot axis, and upon such pivotal movement, applies a return force to urge the connector toward a start position.
The resilient joint subassembly can comprise opposed first and second springs or spring elements spaced apart relative to the longitudinal axis of the prosthetic foot. These springs can differ in size, stiffness, material, and the size of their openings, and are positioned respectively towards the toe and heel portions of the foot. The ankle assembly can include an ankle body with inner surfaces to receive the resilient joint subassembly and outer surfaces to engage interior surfaces of the prosthetic foot's receptacle, forming a tapered connection configured to withstand tensile stresses during walking.
The foot-ankle system includes a prosthetic foot having a receptacle with toe and heel portions spaced apart and an ankle assembly as described. The system allows for mechanical coupling with a prosthetic leg and permits pivotal movement of the endoskeletal connector. This design facilitates quick exchange of prosthetic feet suitable for different heel heights without the need for realignment by the user, thereby overcoming limitations of current prosthetic feet that are restricted to a narrow range of heel heights and require manual alignment.
Claims Coverage
The patent claims include multiple independent claims covering an ankle assembly, a foot-ankle system comprising such an ankle assembly and prosthetic foot, and methods of using the foot-ankle system. The main inventive features relate to the resilient joint subassembly structure and its mechanical interaction with the prosthetic foot and leg connectors.
Resilient joint subassembly permitting pivotal movement and return force
An ankle assembly comprising a resilient joint subassembly configured for at least partial receipt within a receptacle defined by a prosthetic foot with toe and heel portions. The resilient joint subassembly permits pivotal movement of an endoskeletal connector from a start position about a transverse pivot axis perpendicular or oblique to the foot's longitudinal axis. Upon such forward or rearward pivotal movement, the resilient joint subassembly applies a return force urging the connector toward the start position.
Opposed springs or spring elements spaced relative to foot longitudinal axis
The resilient joint subassembly includes opposed first and second springs (e.g., C-springs) or opposed spring elements spaced apart relative to the longitudinal axis of the prosthetic foot. These springs may differ in size, stiffness, material, and opening size. They are positioned such that one spring is between the other and the toe portion, with their openings facing towards respective foot portions (toe or heel).
Mount body secured to endoskeletal connector and pivotable relative to ankle body
The resilient joint subassembly includes a mount having a mount body made of resilient material with an upper portion secured to the endoskeletal connector and a lower portion extending downward. A pin secures the upper portion to the ankle body, allowing the mount body to pivot relative to the ankle body. Opposed first and second spring elements engage inner surfaces of the ankle body and are positioned between the mount body's lower portion, providing control of pivotal motion.
Tapered ankle body for tapered connection within prosthetic foot receptacle
The ankle body has a taper configured to engage a sloped or tapered inner surface of the prosthetic foot's receptacle. This configuration defines a tapered connection with a posterior aspect designed to receive the greatest portion of tensile stress generated during the late stance phase of walking.
Use of endoskeletal connector as mechanical coupling to prosthetic leg
The endoskeletal connector secured to the resilient joint subassembly is configured as a pyramid connector for mechanical coupling with a prosthetic leg.
The claims cover an ankle assembly and foot-ankle system designed to allow pivotal movement with energy return, including details of resilient springs, a resilient mount body pivoting about a pin within an ankle body, and a tapered connection to the prosthetic foot. Methods cover assembling and switching the ankle assembly between prosthetic feet accommodating differing heel heights, with the endoskeletal connector coupling to a prosthetic leg.
Stated Advantages
Allows quick and easy exchange of prosthetic feet for shoes of different heel heights without requiring user alignment adjustments.
Provides a biomimetic roll-over shape during walking accommodating a wide range of heel heights.
Offers a lightweight, inexpensive, and easy-to-use prosthetic ankle-foot system compared to current adjustable heel-height prosthetic feet.
Facilitates natural ankle motion with energy storage and return properties via resilient joint subassemblies.
Documented Applications
Prosthetic device for lower limb amputees to quickly and easily change footwear of varying heel heights.
Adjustable ankle-foot prosthetic systems designed to fit into different shoe types, supporting various heel heights.
Prosthetic foot-and-ankle systems used by Veterans and other amputees requiring compatibility with female footwear or high heel shoes.
Method of using an ankle assembly with interchangeable prosthetic feet within different shoes without alignment changes.
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