Compression-Stabilized Prosthetic Socket With Longitudinal Channels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional prosthetic sockets fail to effectively prevent lost motion between the socket and the underlying skeletal structure, leading to instability and discomfort for amputees, as they merely encapsulate the limb without addressing tissue displacement and compression.
Innovation Solution
The development of a compression-stabilized socket interface with deep channels and relief areas, where channels are created along the length of the bone to compress tissue against the bone, and relief areas are provided between channels to accommodate tissue displacement, using a jig-assisted casting process and materials like carbon fiber for added strength and comfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional encapsulating socket is used to contain the soft tissue, then the socket structure is simple and easy to manufacture, but it fails to prevent lost motion between the socket and the underlying skeletal structure
Solution Approach 1:
The socket is segmented into distinct functional zones: compression channels that apply focused pressure to specific anatomical locations, relief areas that accommodate tissue displacement, and stabilization regions. This segmentation allows the socket to address multiple stability requirements simultaneously while maintaining a manageable structural complexity
Solution Approach 2:
Different regions of the socket are designed with locally optimized properties: compression channels provide high localized pressure to prevent bone movement, relief areas provide low pressure to accommodate tissue, and transition zones provide gradient pressure distributions. This local quality approach enhances stability without requiring the entire socket structure to be overly complex
2Reliability
If compression is applied to compress tissue against the bone, then lost motion is reduced and stability is improved, but tissue displacement occurs requiring relief areas
Solution Approach 1:
The design converts the potentially harmful effect of tissue displacement into a beneficial feature by creating relief areas that anticipate and accommodate tissue movement. The compression channels apply pressure to stabilize the bone, while the adjacent relief areas provide a designated space for displaced tissue to migrate, transforming what would be a harmful displacement into a controlled and beneficial tissue migration pattern
Solution Approach 2:
The socket design incorporates relief areas in advance during the socket fabrication process, before the user experiences any tissue displacement. This preliminary preparation ensures that when compression is applied and tissue naturally displaces, the tissue has a pre-designed pathway and space to migrate, preventing discomfort and skin issues
3Manufacturing precision
If deep channels are formed in the socket to compress tissue, then the fit and stability are improved, but the manufacturing process becomes more complex
Solution Approach 1:
Compression bars are applied to the limb during the casting process itself, before the socket material sets. This preliminary application of compression allows the channels to be formed directly in the mold, capturing the exact compression geometry needed. The bars are removed after casting, leaving precisely formed channels without requiring complex secondary machining or forming operations
Solution Approach 2:
Compression bars serve as intermediary tools during manufacturing. These temporary structures are placed on the limb, plaster is applied over them to form the socket, and then the bars are removed. The bars mediate the transfer of the desired compression geometry from the manufacturer's intent to the actual socket structure, achieving high manufacturing precision through a relatively simple process
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
This design significantly reduces lost motion, enhances stability, and improves the fit of the prosthetic limb by selectively compressing tissue against the bone while allowing displaced tissue to migrate, resulting in a more comfortable and effective transfer of skeletal movement.
Implementation Method 1
The compression areas, 9, 17, are configured and aligned such that they transfer skeletal movement as efficiently as possible such that interface response to volitional movement and interface stability are maximized
Implementation Method 2
Relief Area—is the region in a socket system between two channels or around or near a compressed area which provides a place for the displaced tissue to migrate
Data Source
AI summary
A method for reducing motion of a skeletal structure in a limb towards a wall of an interface is described. The interface comprises a plurality of compression areas that are longitudinally-shaped and oriented longitudinally along the length of limb. The method comprises selecting, during a process of creating the interface, a compression level for the compression areas that compresses soft tissue against the skeletal structure. The method also comprises donning the interface over the limb to apply a plurality of compressive forces that is sufficient to aid in suspension of the interface on the limb and reduce motion of the skeletal structure toward a wall of the interface.