Bidirectional Valve with Segmented Elastomeric Disk for Pressure Control

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Solution Overview

Problem

Existing bidirectional valves, such as cross-slit dome valves, face challenges in manufacturing precision, leading to potential leaks and variations in threshold pressures, which can result in ineffective sealing and contamination prevention in vascular access catheters.

Innovation Solution

A normally closed bidirectional valve design featuring an elastomeric disk with distinct regions that interact with different valve seats, allowing for controlled threshold pressures in both flow directions, utilizing an overlapping channeling system to ensure effective flushing and sealing, and incorporating dual-material construction for enhanced flexibility and manufacturability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a cross-slit dome valve is used to provide bidirectional flow control, then the valve structure is simple, but the manufacturing precision is poor leading to leaks and threshold pressure variations

Engineering Contradiction:
Improvevalve structureVSAvoidslit cutting precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The valve disk is segmented into distinct regions (central region and outer peripheral region) that interact with different valve seats (first valve seat and second valve seat). This segmentation allows each region to be optimized independently for its specific function, eliminating the need for precise cross-slit cutting while maintaining bidirectional flow control capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the valve disk are designed with different properties to interact with different valve seats. The central region engages with the first valve seat for one flow direction, while the outer peripheral region engages with the second valve seat for the opposite flow direction. This local differentiation enables precise threshold pressure control without requiring high manufacturing precision across the entire valve structure.

Inventive Principle:
Principle #3Local quality

2Device complexity

If a cross-slit dome valve is used, then the valve mechanism is simple, but the sealing reliability is poor due to low-pressure leaks

Engineering Contradiction:
Improvevalve mechanismVSAvoidsealing reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

By dividing the valve disk into central and outer peripheral regions that seal against different valve seats, the invention creates two independent sealing paths. This segmentation ensures that each sealing interface can be optimized for its specific pressure conditions, preventing low-pressure leaks that occur in cross-slit dome valves where a single sealing interface must handle bidirectional flows.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The valve disk acts as an intermediary element that mediates between the two valve seats. Its dual-region design allows it to selectively engage with either the first or second valve seat based on flow direction and pressure conditions, ensuring reliable sealing in both directions without the leakage problems of single-interface slit valves.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a cross-slit dome valve is used, then the valve design is simple, but the threshold pressure control is poor with significant variations

Engineering Contradiction:
Improvevalve designVSAvoidthreshold pressure accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The valve system is segmented into two independent valve-seat interactions, each with its own threshold pressure characteristics. The central region-valve seat interface controls threshold pressure for one flow direction, while the outer peripheral region-valve seat interface controls threshold pressure for the opposite direction. This segmentation eliminates the threshold pressure variations inherent in cross-slit dome valves.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Each region of the valve disk is designed with specific local properties to achieve precise threshold pressure control for its designated flow direction. The central region is optimized for engagement with the first valve seat at a specific threshold pressure, while the outer peripheral region is optimized for the second valve seat at a different threshold pressure, enabling accurate bidirectional pressure control.

Inventive Principle:
Principle #3Local quality

4Device complexity

If a single valve seat is used in a dome valve, then the structure is simple, but the bidirectional threshold pressure differentiation is limited

Engineering Contradiction:
Improvevalve seat configurationVSAvoidbidirectional pressure control
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The valve system uses two distinct valve seats (first valve seat and second valve seat) positioned at different locations and orientations. This segmentation enables the valve to provide different threshold pressures for bidirectional flows, with each valve seat optimized for its specific flow direction, thereby enhancing adaptability while maintaining structural simplicity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and second valve seats are positioned asymmetrically relative to the valve disk and housing. This asymmetric configuration, combined with the dual-region valve disk design, enables significantly different threshold pressures for opposite flow directions, providing superior bidirectional pressure control compared to symmetric single-seat dome valves.

Inventive Principle:
Principle #4Asymmetry

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 robust, easily manufacturable valve with precise control over opening pressures, ensuring effective sealing and flushing, while preventing contamination and blood loss, with a large difference in threshold pressures between infusion and aspiration directions.

Implementation Method 1

An elastomeric disk is disposed between the first and second port in the internal housing volume, and retained against the housing within an annular region of the elastomeric disk between a central region and an outer peripheral region. In this way, a central region and outer peripheral region of the valve disk are free to move with respect to the housing.

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The housing provides first flow channels leading from the first port to the elastomeric disk to press the elastomeric disk against the second valve seat and to press the elastomeric disk away from the first valve seat when pressure at the first port is greater than pressure at the second port.

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3010578B1Bidirectional valve with improved threshold pressure accuracy
Publication Date: 2019.01.16 ILLINOIS TOOL WORKS INC
  • EP3010578B1 patent drawingFigure 1~3
  • EP3010578B1 patent drawingFigure 4~5
  • EP3010578B1 patent drawingFigure 6~7

AI summary

A bidirectional valve for medical use or the like provides different threshold opening pressures in different directions using a valve seat and flapper construction providing improved characterization in operation in contrast to cross-slit valves often used for bidirectional operation. A valve disk supported in a central annular region provides movable portions engaging in valve seats at a peripheral region and a central region.