Prosthetic Liner Locking Attachment Internalizing Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing prosthetic liners with distal locking systems face issues of lack of strength and security due to reliance on adhesive bonds and physical engagement with fabric, requiring destructive inspection and potential separation or pistoning, and lack of manufacturing efficiency.
Innovation Solution
A novel screw cap attachment system where the locking base resides within the liner, with an external screw cap securing to the fabric, providing internal locking and eliminating the need for embedding in the elastomer gel or engaging with the outer fabric, allowing for enhanced strength, safety, and non-destructive inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive materials, grommetting, or molding methods are used to secure the distal portion of the liner, then the locking system can be attached to the prosthetic liner, but the attachment lacks sufficient strength and security, potentially causing separation or pistoning
Solution Approach 1:
The locking attachment base is merged with the elastomeric matrix by embedding it within the matrix material during the molding process. This creates a unified structure where the locking base becomes an integral part of the liner body, eliminating weak adhesive bonds or mechanical fasteners that could fail. The locking base is positioned such that it is surrounded by and bonded to the elastomeric material, distributing stresses and preventing separation.
Solution Approach 2:
The locking attachment base is nested within the elastomeric matrix, with the base embedded inside the molded material. This nested configuration allows the locking mechanism to be housed within the liner body rather than attached to the exterior, creating a more secure and integrated assembly that resists pistoning and separation forces.
2Ease of manufacture
If the distal umbrella is mounted to the external surface of the fabric, then the locking system can be attached, but additional effort is needed to add a grommet to ensure secure attachment
Solution Approach 1:
The locking attachment base is merged into the elastomeric matrix during the molding process, eliminating the need for separate grommet installation or adhesive application steps. The base becomes an integral part of the molded liner, simplifying manufacturing by combining multiple operations into a single molding cycle.
Solution Approach 2:
The locking attachment base is pre-positioned and embedded within the elastomeric matrix during the molding process, before the liner is assembled. This preliminary integration eliminates the need for subsequent grommet installation or securement operations, reducing manufacturing complexity and ensuring consistent attachment quality.
3Reliability
If the locking system requires destructive inspection of the liner, then bonding surfaces can be examined, but the liner is destroyed in the process
Solution Approach 1:
The locking attachment base is designed with external indication features that replicate or indicate the internal bonding quality without requiring physical access to the bonding surfaces. The molded structure provides external signs that verify the integrity of the internal bond between the locking base and elastomeric matrix, allowing inspection without destruction.
Solution Approach 2:
The locking attachment base is nested within the elastomeric matrix in a way that creates external accessible features or indicators. This nested configuration allows the internal bonding quality to be verified through external examination of the molded structure, eliminating the need for destructive dissection to inspect the bonding surfaces.
4Ease of operation
If the locking attachment is external to the liner body, then it can be accessed easily, but it lacks the strength and security of an internal locking mechanism
Solution Approach 1:
The locking attachment base is nested within the elastomeric matrix of the liner body, creating an internal locking mechanism. The base is embedded in the molded material, surrounding it with strengthening elastomeric material that distributes and resists applied stresses, thereby increasing the overall strength and security of the locking system while maintaining accessibility through the liner opening.
Solution Approach 2:
The locking attachment base is integrated with the elastomeric matrix to create a composite structure. The base material and elastomeric matrix work together as a unified composite, combining the structural properties of both materials to achieve superior strength and security compared to external attachments or adhesive bonds alone.
Data Source
AI summary
A prosthetic liner incorporating a locking attachment that can be used by amputees to engage their prosthetic liner with a prosthetic device. The prosthetic liner has an open proximal end and a closed distal end with a liner opening at the closed distal end. The prosthetic liner further comprises an external fabric layer and an internal elastomer layer. This internal elastomer layer may be made of silicone, urethane, or a thermoplastic styrene-based elastomer gel. The locking attachment is comprised of two parts: an umbrella further comprising a stem having a base and the exterior screw cap. The exterior screw cap can engage the umbrella in a variety of ways including, but not limited to, locking grooves, locking studs, and locking teeth. In addition, the locking attachment has an internally threaded central aperture that allows for the expulsion of air as well as the mounting of a prosthesis.