Prosthetic foot/ankle system with automatic alignment
Inventors
Hansen, Andrew Howard • Iversen, Edwin Kay • Nickel, Eric Alexander • Voss, Gregory O. • Jacobs, Gregory James • Greene, Carter J. • Christenson, Jeffery David
Assignees
US Department of Veterans Affairs • Motion Control
Publication Number
US-12186212-B2
Publication Date
2025-01-07
Expiration Date
2041-10-21
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Technology is described to provide a foot and ankle prosthesis for individuals with lower limb loss. This technology is able to store and release energy and individuals or patients who are using the foot/ankle prosthesis may be able to expend less energy when walking. The system includes a hydraulic damper attached to dynamic energy storing spring elements. The axis of rotation of the system can be near to that of an intact human ankle, providing biomimetic function. The system can utilize spring elements based on the vertical displacement of the center of pressure of an intact normal foot. A hydraulic system can provide user adjustable heel height and adaptation to inclines. The dorsiflexion and plantar flexion resistances can be independently adjusted manually or electrically. In addition, the system can be automatically locked in dorsiflexion when loaded and unlock when unloaded.
Core Innovation
The invention describes a prosthetic foot and ankle system designed for individuals with lower limb loss that can store and release energy, enabling users to expend less energy during walking or running. The system includes a linear hydraulic damper attached via a revolute joint to dynamic energy storing spring elements. The axis of rotation is positioned near that of an intact human ankle to provide biomimetic function, closely mimicking the natural foot and ankle movements.
The system incorporates spring elements shaped to allow vertical displacement of the center of pressure similar to an intact foot. It features user-adjustable heel height and inclination adaptation through mechanisms such as an adjustable sliding yoke. The dorsiflexion and plantar flexion resistances can be independently adjusted manually or electrically, and the system can automatically lock in dorsiflexion when loaded and unlock upon unloading to allow natural gait dynamics.
Claims Coverage
The patent includes three independent claims covering different configurations of a prosthetic foot and ankle system with hydraulic and spring components providing automatic alignment and adjustable resistance.
Weighted hydraulic cylinder lock for automatic dorsiflexion control
A hydraulic cylinder lock using a weighted valve mechanism that locks the revolute joint for dorsiflexion between heel strike and foot flat and unlocks for dorsiflexion upon toe unloading, enabling automatic dorsiflexion by a toe-lift spring.
Biomimetic energy storing components and hydraulic damping
A prosthetic foot with a foot support, main spring, and energy storing sole plate connected through a revolute joint, combined with a linear hydraulic damper providing resistive communication and adjustable dorsiflexion and plantar flexion resistance, mimicking natural foot mechanics.
User alignment with remnant limb and adjustable shock absorption
Inclusion of a mounting pyramid to enable alignment with a remnant limb and hydraulic valves (manual or electric) for independent adjustment of dorsiflexion and plantar flexion resistance to vary heel strike shock absorption and prevent foot slap.
The inventive features focus on a prosthetic foot/ankle system combining biomimetic energy-storing springs and hydraulic damping with an automatic weighted valve lock mechanism, adjustable resistance, and user alignment capability to improve gait symmetry and adaptability.
Stated Advantages
Allows individuals using the prosthetic foot/ankle to expend less energy when walking or running.
Provides biomimetic function by positioning the axis of rotation near that of an intact ankle, enabling more symmetric gait.
Enables user adjustable heel height and adaptation to slopes and inclines for better comfort and performance.
Allows independent adjustment of dorsiflexion and plantar flexion resistance to optimize shock absorption and prevent foot slap.
Automatic locking in dorsiflexion when loaded and unlocking when unloaded facilitates natural gait phases and reduces stumbling and hip hiking.
Documented Applications
Use as a foot and ankle prosthesis for individuals with lower limb loss to improve walking and running efficiency.
Adaptation to varying heel heights and uneven or inclined walking surfaces for amputees.
Interested in licensing this patent?