Prosthetic Liner Anchoring with Dual Straps
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Solution Overview
Problem
Existing prosthetic anchoring systems for above-the-knee amputees face issues with stability, as they often rely on single attachment points, leading to extraneous pivoting, rotation, and shift during ambulation, and fail to adjust comfortably with volume changes in the limb, causing discomfort and potential dislodgment.
Innovation Solution
A prosthetic anchoring system featuring top-side and lower mechanical attachments with a reinforcement plate having a high-density molded hook backing that removably adheres to the liner, providing secure anchors for straps and preventing lateral and rotational movement, while allowing for easy adjustment through Velcro® closure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single attachment point is used to secure the liner to the socket, then the device complexity is reduced, but the stability deteriorates due to extraneous pivoting, rotation, and shift during ambulation
Solution Approach 1:
The single attachment point is segmented into multiple attachment points (first and second attachment points) distributed around the circumference of the liner. This segmentation allows the liner to be secured at multiple locations, preventing pivoting and rotation while maintaining manageable device complexity through a modular attachment system.
2Reliability
If radial pressure is applied by tightening belts to secure the limb, then the socket fit is improved, but the comfort deteriorates due to uneven squeezing and pain
Solution Approach 1:
Instead of applying radial pressure uniformly through belts, the system uses localized attachment points with straps that can be independently adjusted. This allows pressure to be distributed more evenly across the limb surface, securing the socket fit while reducing concentrated pressure points that cause discomfort and pain.
3Reliability
If a distal pin is used for docking and locking the socket, then the connection security is improved, but the ease of operation deteriorates due to difficulty engaging and pain associated with pin insertion
Solution Approach 1:
The mechanical pin docking system is replaced with a strap-based attachment system that uses friction and tension rather than rigid mechanical interlocking. This substitution eliminates the need for precise pin insertion while maintaining connection security through the distributed strap attachments that secure the liner to the socket.
4Stability of the object's composition
If the anchoring system is fixed to prevent movement, then the stability is improved, but the adaptability deteriorates when limb volume changes throughout the day
Solution Approach 1:
The anchoring system incorporates dynamic elements through adjustable straps that can be loosened or tightened as limb volume changes throughout the day. The straps maintain secure attachment while allowing for volume adjustments, transforming a static fixed system into a dynamic adaptive system that responds to physiological changes.
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 system enhances stability and comfort by preventing extraneous motion and allowing for easy adjustment to accommodate volume changes, maintaining a secure fit without causing pain or dislodgment, and can be easily repositioned for optimal fit.
Implementation Method 1
a reinforcement plate having a high-density molded hook backing that removably adheres to the liner
Data Source
AI summary
An anchoring system for a transtibial or transfemoral (above or below the knee) prosthesis. The anchoring system includes a liner for enveloping an amputee limb. The liner has a first strap releasably secured to the fabric of the liner by a reinforcement plate that has a particular molded hook backing that removably adheres to the liner in such a way as to still provide a secure anchor for the buckle. The liner also has a second strap fixedly attached to the distal bottom end of the liner. The anchoring system also includes a containment socket for seating the liner. The containment socket has a pair of slots there through at positions corresponding to the two straps of the liner, respectively. To apply the anchoring system, the patient first applies the liner to his/her limb. The liner is then inserted into the socket with the two fastening straps protruding out through the respective slots. The patient pulls down on the lower strap thereby drawing the liner down into the socket until the liner is securely seated in the socket. When fully seated, the two fastening straps are overlayed and secured to themselves by Velcro® or the lower strap is threaded through a buckle on the upper strap and secured onto itself with Velcro®. The foregoing forms a suspension which holds the prosthesis on. Moreover, the fastening straps through slots absolutely prevent lateral shift as well as rotation.