Distensible Suspension Liner Seal for Prosthetic Socket
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Solution Overview
Problem
Existing suspension liners for prosthetic sockets face challenges in effectively sealing the interface between a residual limb and the socket, particularly for trans-tibial amputees due to bony protuberances and volume fluctuations, which impair the seal's effectiveness and comfort.
Innovation Solution
A suspension liner with an elongate, conical body and radially extensible seal elements, featuring a volume control pad that can be selectively adjusted and pressurized to regulate the seal's extension, providing a secure and adjustable interface between the residual limb and the prosthetic socket.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed seal element is used in the suspension liner, then the structure is simple, but the seal effectiveness deteriorates due to volume fluctuations and bony protuberances
Solution Approach 1:
The seal element is designed to be distensible rather than fixed, allowing it to dynamically adjust its configuration in response to volume fluctuations of the residual limb and irregularities such as bony protuberances. This dynamic adaptation maintains reliable sealing without requiring complex adjustable mechanisms.
Solution Approach 2:
The seal element's physical parameters (shape, volume, position) are changed in response to environmental conditions (limb volume fluctuations). This allows the seal to adapt to varying conditions while maintaining simplicity in the overall structure.
2Object-affected harmful factors
If the suspension liner is thickened to provide cushioning, then comfort is improved, but the seal effectiveness deteriorates due to interference with bony protuberances
Solution Approach 1:
The liner is designed with non-uniform thickness, providing cushioning in areas where comfort is needed while maintaining thinner sections in areas requiring effective sealing. This local differentiation allows both comfort and seal effectiveness to coexist without interference from bony protuberances.
3Stability of the object's composition
If a reinforcement layer is added to resist axial elongation, then structural stability is improved, but radial distension is restricted
Solution Approach 1:
The reinforcement layer is strategically positioned and oriented to provide axial support while leaving radial directions relatively unrestricted. This segmented approach to reinforcement allows the liner to maintain axial stability while preserving the ability to radially adapt to the residual limb's shape and volume 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 solution enhances the sealing effectiveness and comfort by distributing traction evenly, reducing pressure peaks and accommodating volume fluctuations, thereby improving the retention and fit of the residual limb within the socket.
Implementation Method 1
a volume control pad located between the body portion and the seal element and arranged to distend from the body portion and urge the seal element outwardly
Implementation Method 2
The elastomer constituting the suspension liner member frictionally engages and remains attached to the skin of a residual limb
Implementation Method 3
suction is created in the distal end of the socket tending to retain the suspension liner within the socket
Data Source
AI summary
A suspension liner is adapted to provide an interface between a residual limb and a prosthetic socket. The liner includes an elongate, generally conical body portion, and a volume control pad located along the body portion. The volume control pad is arranged to distend outwardly from the body portion. A resilient seal element is connected to the body portion and protrudes radially from the body portion, and is located in correspondence with the volume control pad.