Prosthetic Valve Membrane Airflow and Snag Reduction

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Solution Overview

Problem

Conventional valve systems for prosthetic devices suffer from poor air flow and air resistance, leading to delayed secure fits, increased risk of disengagement, and discomfort due to protruding components, which can snag on objects and compromise the sealing strength, ultimately affecting the suspension and ease of donning and doffing.

Innovation Solution

A valve with a membrane having independently operating portions that respond to different triggers, allowing for efficient air regulation with low air resistance, featuring a low-profile housing to minimize snagging risks and improve air flow, enabling quick expulsion and introduction of air without re-entry, thus enhancing suspension and reducing the number of steps for a tight fit.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional valve systems are used with prosthetic sockets, then air can be expelled to maintain negative pressure, but air flow is poor and air resistance is high, causing delayed secure fit and decreased suction

Engineering Contradiction:
Improveair flow efficiencyVSAvoidtime to achieve secure fit
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The valve system is segmented into distinct functional components: a valve member with a valve seat, a biasing member, and a suction cup. This segmentation allows each component to be optimized independently - the suction cup creates a seal and negative pressure zone, the biasing member provides restoring force, and the valve member controls air flow. This modular approach improves overall air flow efficiency compared to integrated conventional designs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The suction cup is extracted as a separate component from the socket structure, allowing it to be positioned optimally for creating negative pressure. The valve system is also extracted as a distinct assembly that can be independently optimized for air flow characteristics. This separation enables the suction mechanism and valve mechanism to work independently yet cooperatively, improving air evacuation efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If conventional valve systems with protruding components are used, then air can be vented, but the protruding parts increase the chance of snagging and damage

Engineering Contradiction:
Improvesealing strengthVSAvoidsnagging and damage risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The valve member is nested within the valve housing, and the entire valve assembly is integrated into the socket structure. The suction cup is nested within the socket, creating a hierarchical nested arrangement. This nesting eliminates protruding components that could snag on objects, while maintaining the sealing interface between the suction cup and socket interior. The valve seat is nested within the valve housing, allowing the valve member to move freely without external exposure.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The suction cup is made from a flexible material that can deform to create a seal against the socket interior. This flexible membrane approach maintains sealing strength without requiring rigid protruding components. The valve member also utilizes flexible sealing surfaces that conform to the valve seat, ensuring reliable sealing while avoiding sharp or protruding edges that could snag.

Inventive Principle:
Principle #30Flexible shells and thin films

3Productivity

If conventional valve systems are used, then air can be expelled, but the sealing strength is insufficient or limited, compromising suspension

Engineering Contradiction:
Improveair expulsion capabilityVSAvoidsuspension stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The biasing member is pre-loaded to maintain the valve member in a sealed position against the valve seat before air expulsion is needed. This preliminary positioning ensures that the valve is ready to open immediately when air pressure differential occurs, enabling rapid air expulsion. The suction cup is also pre-positioned to create initial negative pressure, preparing the system for efficient air evacuation when the valve opens.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The valve system provides automatic feedback control of air pressure within the socket. When air pressure increases (positive pressure relative to ambient), the pressure differential automatically opens the valve member, allowing air to escape. When air pressure decreases (negative pressure), the biasing member automatically closes the valve to maintain the vacuum. This feedback mechanism maintains optimal suspension conditions without user intervention.

Inventive Principle:
Principle #23Feedback

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 improves air flow and reduces air resistance, allowing for faster and more efficient donning and doffing of prosthetic devices by automatically expelling air and maintaining a snug fit, reducing the likelihood of disengagement and damage to the valve system.

Implementation Method 1

The differential air pressure is routinely referred to as suction or vacuum by those having skill in the art. Using a valve should allow air to be expelled from the socket in order to maintain at least a slight negative pressure for creating the suction against the residual limb.

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

The differential air pressure is routinely referred to as suction or vacuum by those having skill in the art. Using a valve should allow air to be expelled from the socket in order to maintain at least a slight negative pressure for creating the suction against the residual limb.

Methodology Applied
Scientific EffectSuction: Suction

Implementation Method 3

a biasing member biasing the valve member to its seated position

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3125830B1Valve for prosthetic device
Publication Date: 2018.02.28 OSSUR ICELAND EHF
  • EP3125830B1 patent drawingFigure 1
  • EP3125830B1 patent drawingFigure 2~3A
  • EP3125830B1 patent drawingFigure 3B~3C

AI summary

A valve for use with a prosthetic socket includes a body defining an upper opening, a lower opening adapted to be in fluid communication with the socket cavity, and a passageway formed between the openings. A membrane is flexibly seated on the body over the upper opening. The membrane is moveable between a closed position in which the upper opening is sealed such that fluid communication between the upper opening and the lower opening is inhibited, and an open position in which the upper opening is unsealed such that fluid can flow through the passageway. The membrane includes a first part connected to a release element that is operable to move the membrane between the open and closed positions, and a free part operable independent of the first part to move the membrane between the open and closed positions.