Medical Valve Variable-Diameter Seal for Low-Resistance Insertion

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Solution Overview

Problem

Existing medical valves, such as hemostatic and iris valves, suffer from deformation, tearing, and leakage issues due to their design limitations, particularly when accommodating a variety of differently sized medical devices during procedures, leading to fluid loss and increased resistance.

Innovation Solution

A medical valve assembly with a variable seal mechanism using an elastomeric seal compressed between a plunger plate and a flange, actuated by a coil spring or leaf spring cage, allowing for adjustable inner diameter through manual operation, ensuring a reliable seal across various device sizes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a disk valve is modified to accommodate differently sized medical devices with increased tensile and elongation properties, then adaptability is improved, but resistance increases and excessive force is required for insertion and withdrawal

Engineering Contradiction:
Improveadaptability to different device sizesVSAvoidforce required for insertion and withdrawal
Core Design Contradiction:
Adaptability or versatilityVSForce

Solution Approach 1:

The seal diameter is made dynamically adjustable through a variable diameter mechanism that allows the seal to change its inner diameter based on the size of the medical device being inserted. This dynamic adjustment enables the seal to adapt to different device sizes without requiring excessive tensile strength or elongation properties, thereby reducing the force needed for insertion and withdrawal while maintaining adaptability.

Inventive Principle:
Principle #15Dynamics

2Reliability

If an elastomeric sleeve is twisted and constricted to effectuate closure in an iris valve, then sealing capability is improved, but wear increases through tearing

Engineering Contradiction:
Improvesealing capabilityVSAvoidservice life of elastomeric sleeve
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The variable diameter mechanism provides dynamic control over the seal's opening size, allowing the seal to be opened or closed by adjusting the inner diameter rather than through continuous twisting and constriction. This reduces mechanical stress and wear on the elastomeric material, extending its service life while maintaining reliable sealing capability when closed.

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If a single medical valve is used to insert multiple medical devices of different sizes, then device versatility is improved, but fluid loss increases due to inability to quickly adjust

Engineering Contradiction:
Improveability to accommodate multiple devicesVSAvoidfluid loss through valve
Core Design Contradiction:
Adaptability or versatilityVSLoss of substance

Solution Approach 1:

The variable diameter mechanism enables rapid adjustment of the seal's inner diameter to match different medical device sizes. This dynamic adaptation allows the single valve to maintain an effective hemostatic seal across multiple device exchanges without significant fluid loss, combining versatility with fluid containment efficiency.

Inventive Principle:
Principle #15Dynamics

4Reliability

If the inner diameter of the elastomeric seal is decreased to establish a closed condition, then sealing capability is improved, but resistance to device insertion increases

Engineering Contradiction:
Improvesealing capabilityVSAvoidresistance to device insertion
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The variable diameter mechanism allows the seal to maintain a larger inner diameter during device insertion, reducing resistance and the force required. Once the device is in place, the inner diameter can be decreased to establish a closed sealing condition. This dynamic adjustment separates the insertion phase from the sealing phase, optimizing both low resistance during insertion and reliable sealing when closed.

Inventive Principle:
Principle #15Dynamics

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 provides a consistent and predictable seal for multiple medical devices, minimizing fluid loss and reducing wear, while maintaining low resistance during insertion and withdrawal.

Implementation Method 1

An elastomeric seal is compressed between the plunger plate and the flange... A coil spring is disposed within said valve housing and is compressed between said first valve housing end and said plunger plate for applying a compression force to said plunger plate for compressing said elastomeric seal

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3563901B1A medical valve with a variable diameter seal
Publication Date: 2025.09.10 FREUDENBERG MEDICAL LLC
  • EP3563901B1 patent drawingFigure 1
  • EP3563901B1 patent drawingFigure 2
  • EP3563901B1 patent drawingFigure 3~4A

AI summary

A medical valve assembly includes a tube extending between a first and second tube end along an axis, and a plunger plate extends radially from the second tube end. A valve housing surrounds the tube and includes a radially inwardly extending flange. A compression member is biased against the plunger plate and compresses an elastomeric seal from a non-compressed condition to a compressed condition to establish a sealed condition of the medical valve assembly. An inner surface of the elastomeric seal in the non-compressed condition has a plurality of planar portions and a plurality of radiused portions, with adjacent planar portions interconnected with one of the radiused portions to improve a closure of the elastomeric seal during compression. The inner surface preferably includes three planar portions and three radiused portions to define a generally triangular-shaped inner surface as viewed in cross section in the non-compressed condition.