Prosthetic Foot Vacuum Pump for Sleeve-Free Socket Suspension
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Solution Overview
Problem
Existing prosthetic vacuum suspension systems fail to adapt to limb volume changes during walking, often lose suction, and are bulky, restricting range of motion and requiring sleeves that add material thickness and weight.
Innovation Solution
A prosthetic device with a distal vacuum pump mechanism that generates negative pressure inside the socket, using a prosthetic foot's movement to draw air out during heel strike and expel it during swing phase, maintaining secure suspension without a sleeve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sleeve is used to seal the socket and achieve vacuum suspension, then vacuum seal is improved, but range of motion is restricted and material thickness increases
Solution Approach 1:
The patent removes the traditional sleeve component entirely and replaces it with a sealing mechanism integrated into the liner itself. The liner includes a seal at its proximal end that interfaces directly with the socket opening, eliminating the need for a separate sleeve while maintaining the vacuum seal function.
Solution Approach 2:
The sealing function is merged with the liner by integrating a seal directly into the liner structure. The liner comprises a seal at its proximal end that forms an airtight interface with the socket, combining the liner and sleeve functions into a single integrated component.
2Reliability
If a sleeve is used to achieve vacuum suspension, then vacuum seal is improved, but device weight and bulk increase
Solution Approach 1:
The patent eliminates the separate sleeve component, thereby removing its weight and bulk from the system. The vacuum seal function is achieved through the integrated liner seal, reducing overall device weight while maintaining sealing effectiveness.
3Reliability
If vacuum is applied along the entire residual limb to achieve suspension, then suspension effectiveness is improved, but adaptation to volume change is reduced
Solution Approach 1:
The patent concentrates the vacuum seal at the proximal end of the liner where it interfaces with the socket opening, rather than distributing it along the entire length. This localized sealing approach allows the distal portions of the residual limb to accommodate volume changes while maintaining effective suspension through the proximal seal.
4Reliability
If a mechanical vacuum pump is added to provide vacuum assistance, then suspension reliability is improved, but device complexity increases
Solution Approach 1:
The vacuum pump mechanism is designed to be automatically actuated by the user's own gait motion. The pump includes a piston that is driven by the movement of the prosthetic limb during walking, eliminating the need for external power sources or complex control systems while maintaining reliable vacuum generation.
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 provides secure, lightweight, and reliable vacuum suspension by stabilizing soft tissue volume, reducing the risk of leakage, and allowing unrestricted motion, while minimizing volume fluctuations and weight.
Implementation Method 1
The pump mechanism is arranged to draw air from the prosthetic socket interior upon expansion of the pump mechanism
Implementation Method 2
The pump mechanism has a second port including a one-way valve arranged for expelling air drawn from the prosthetic socket interior
Implementation Method 3
The seal component is located on a distal end of the suspension liner and circumferentially engages the interior wall of the prosthetic socket defining an interior of the prosthetic socket
Data Source
AI summary
A prosthetic system includes a prosthetic foot defining an upper surface and having a flexible configuration andincluding a movable member and a pump system attached to the prosthetic footmechanism. The pump system includes a pump mechanism definingdefines a fluid chamber having variable configuration and an actuating partpositioned between the member and the foot. The actuating part is arranged to selectively engage with and separate a distance from the upper surface of the foot plate to move the pump mechanism between a first position in which a volume of the fluid chamber is zero or near-zero and a second position in which the volume of the fluid chamber is expanded relative to the first position. The volume of the fluid chamber increases when the actuating part moves away from the upper surface of the foot plate.During heel strike, the member pulls the upper side of the pump forward to expand the fluid chamber; during stance or toe-off, the member pushes the pump backward to compress the fluid chamber. The member includes two non-pivotally joined pieces.