Bi-Modal Ankle-Foot Device Lockable Joint
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Solution Overview
Problem
Current ankle-foot prosthetic devices fail to provide adequate stability during standing and walking for lower-limb amputees, particularly those with vascular-related amputations, leading to balance issues and increased risk of falls.
Innovation Solution
A bi-modal ankle-foot prosthetic or orthotic device that transitions between a curved effective rocker shape for walking and a flattened shape for standing, utilizing a lockable ankle joint and resilient elements to mimic the biological response of able-bodied individuals, thereby enhancing stability and balance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a curved effective rocker shape is provided for walking, then walking efficiency is improved, but stability during standing deteriorates
Solution Approach 1:
The ankle-foot device incorporates a lockable ankle joint that can transition between locked and unlocked states. When unlocked, the device provides a curved rocker shape for efficient walking. When locked, it provides a stable flattened shape for standing. This dynamic reconfiguration allows the device to adapt its geometry based on the user's activity state, resolving the contradiction between walking efficiency and standing stability.
Solution Approach 2:
The device changes its effective shape parameter from curved to flattened by locking or unlocking the ankle joint. This parameter change allows the same device to provide optimal characteristics for both walking (curved shape) and standing (flattened shape), eliminating the need for separate devices for each function.
2Ease of manufacture
If a single fixed shape is provided for the ankle-foot device, then manufacturing simplicity is improved, but adaptability to different functional needs deteriorates
Solution Approach 1:
The ankle-foot device is segmented into a foot piece and an ankle joint assembly that can be independently configured. The ankle joint can be locked or unlocked to change the effective shape, allowing the device to adapt to different functional needs while maintaining relatively simple manufacturing of individual components.
Solution Approach 2:
The lockable ankle joint mechanism enables a single device to perform multiple functions: providing a curved rocker shape for walking when unlocked, and a stable flattened shape for standing when locked. This multi-functionality eliminates the need for separate devices for different activities while keeping the overall structure manageable.
3Stability of the object's composition
If the ankle joint is locked to provide stability during standing, then balance is improved, but walking mobility deteriorates
Solution Approach 1:
The lockable ankle joint allows the user to dynamically switch between locked (stable) and unlocked (mobile) states. During standing, the joint is locked to provide stability and balance. During walking, the joint is unlocked to allow the curved rocker shape to facilitate natural walking motion. This dynamic switching resolves the contradiction between stability and mobility.
4Productivity
If the ankle joint is unlocked to provide curved shape for walking, then walking efficiency is improved, but stability during standing deteriorates
Solution Approach 1:
The lockable ankle joint enables dynamic reconfiguration of the device geometry. When unlocked, the ankle joint allows the device to form a curved rocker shape that facilitates efficient walking. When locked, it creates a stable flattened shape for standing. This dynamic capability allows the device to provide optimal performance for each activity without compromising the other.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The device reduces the occurrence of falls by providing a stable base during standing and facilitating efficient walking, improving balance confidence and mobility for lower-limb amputees, particularly those with diabetes-related or vascular-related amputations.
Implementation Method 1
one or more resilient elements cooperating to provide a curved effective shape for walking
Data Source
AI summary
A bi-modal ankle-foot device that provides a curved effective shape appropriate for walking and a flattened effective shape for standing. The bi-modal ankle-foot device includes a foot piece and a lockable ankle joint connected to the flat foot piece, the ankle joint and foot piece cooperating to provide a curved shape for walking when the ankle joint is unlocked and to provide a flattened shape for standing when the ankle joint is locked.