Prosthetic Foot Membrane Pump for Consistent Vacuum Suspension
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Solution Overview
Problem
Existing prosthetic devices face challenges in securely attaching to the residual limb without causing discomfort or injury, with mechanical pumps being bulky and inconsistent in generating vacuum, and electronic pumps being complex.
Innovation Solution
A prosthetic system with a pump mechanism that generates vacuum automatically during gait by expanding and compressing a foot member, using a movable member to shift between configurations and create a vacuum without bulky components, allowing for a secure and reliable attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical pump is used to generate vacuum, then vacuum can be generated without electronic components, but the pump becomes bulky and adds weight to the prosthetic device
Solution Approach 1:
The patent employs a flexible membrane as the pumping element instead of rigid mechanical components. The membrane expands and contracts to create vacuum, eliminating the need for bulky mechanical pump structures while maintaining vacuum generation capability. This directly resolves the contradiction by using thin-film flexible material to replace heavy mechanical components.
Solution Approach 2:
The patent extracts the essential vacuum-generating function from the bulky mechanical pump structure. By isolating the membrane as the active pumping element and removing unnecessary structural components, the design achieves vacuum generation with minimal weight, directly addressing the weight vs. functionality contradiction.
2Reliability
If frame and support blade components are added to improve vacuum efficiency, then vacuum generation improves, but the device becomes bulkier and heavier
Solution Approach 1:
The flexible membrane serves as both the pumping mechanism and the structural element, eliminating the need for separate frame and support blade components. The membrane's flexibility allows it to perform vacuum generation without requiring additional rigid structural support, thus improving vacuum efficiency while minimizing device volume.
Solution Approach 2:
The membrane performs multiple functions simultaneously: it acts as the pumping surface, the structural support, and the seal. This multi-functionality eliminates the need for separate frame and support blade components, achieving efficient vacuum generation without increasing device volume.
3Reliability
If the pump mechanism engages the heel of the prosthetic foot, then vacuum can be generated, but versatility is limited
Solution Approach 1:
The membrane pump mechanism is designed to be compatible with various prosthetic foot types by engaging at multiple locations including the heel, midfoot, or forefoot. This universal design approach allows the same pump mechanism to work with different prosthetic configurations, enhancing versatility while maintaining reliable vacuum generation.
Solution Approach 2:
The pump mechanism is designed with dynamic engagement points that can adapt to different prosthetic foot geometries. The flexible membrane can engage at varying locations along the prosthetic foot structure, allowing the system to maintain effective vacuum generation across different foot types and configurations.
4Reliability
If complete compression of the pump is required to expel air, then vacuum can be generated, but the system becomes unpredictable and inadequate due to varying user motion
Solution Approach 1:
The membrane pump mechanism automatically generates and expels air through the natural expansion and contraction cycles of the prosthetic foot during user motion. The system self-regulates the compression and expansion phases without requiring complete compression, adapting to varying user motion patterns while maintaining consistent vacuum generation.
Solution Approach 2:
The pump operates through periodic expansion and contraction cycles driven by natural gait motion. Each cycle automatically performs both air intake and expulsion phases, creating consistent vacuum levels without requiring complete compression. The periodic nature of the operation ensures reliable vacuum generation that adapts to varying user motion speeds and patterns.
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 a lightweight, versatile, and efficient vacuum suspension that maintains consistent vacuum levels, reducing discomfort and improving proprioception by minimizing volume fluctuations and pistoning.
Implementation Method 1
the membrane expands, air is efficiently drawn from the socket
Implementation Method 2
generating negative pressure inside a prosthetic socket worn over a residual limb
Implementation Method 3
The weight placed on the foot member of the prosthetic foot expands and compresses the foot member, which, in turn, expands a pump mechanism positioned between the end sections of the foot member
Data Source
AI summary
A prosthetic system includes a prosthetic foot with a foot member defining a first end portion, a second end portion, and an intermediate portion defining a curvature and extending between the first and second end portions. A pump mechanism is coupled to the foot member. The pump mechanism includes a housing defining a cavity, and a membrane situated in the cavity. The pump mechanism is movable between an original configuration and an expanded configuration. A movable member includes a first portion coupled to the membrane and a second portion arranged to slidably engage the foot member. Relative movement between the first and second end portions moves the first portion of the movable member relative to the housing and slides the second portion along a length of the foot member to shift the pump mechanism between the original and expanded configurations.