Check Valve Backflow Prevention in Medical Suction Systems

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Solution Overview

Problem

Current medical suctioning devices fail to adequately prevent backflow of contaminants from the vacuum system into a patient's mouth, leading to a high risk of cross-contamination, particularly due to boundary layer conditions and mouth-induced backflow suction, which is exacerbated by the formation of bio-films.

Innovation Solution

A backflow prevention system featuring a fluid ejector tube with an internal valve seat and a valve flap that automatically disengages upon vacuum application to prevent contaminant backflow, combined with disposable covers for the suction assembly to provide a sanitary barrier.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If a vacuum line is reused between patients without changing the entire suctioning device, then cost and resource utilization are improved, but cross-contamination risk increases due to contaminant backflow from the vacuum line into the distal end

Engineering Contradiction:
Improvevacuum line reuseVSAvoidcross-contamination
Core Design Contradiction:
Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The suctioning device is divided into a reusable proximal portion (vacuum line connection) and a disposable distal portion (saliva ejector tip). This segmentation allows the vacuum line to be reused while the distal portion that contacts the patient is discarded after single use, preventing cross-contamination without wasting the expensive vacuum line infrastructure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A check valve is introduced as an intermediary component in the vacuum line to prevent backflow of contaminants. The check valve allows vacuum to be applied to the distal end during use, but automatically closes to block any backflow when vacuum is released, thereby protecting the reusable vacuum line from contamination while maintaining system reusability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If prior art suctioning devices are used without check valves, then device simplicity is maintained, but boundary layer conditions allow bio-film formation and contaminant backflow into the patient's mouth

Engineering Contradiction:
Improvesuctioning device structureVSAvoidcontaminant backflow
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

A check valve is introduced as an intermediary component in the vacuum line to prevent backflow of contaminants. The check valve allows vacuum to be applied to the distal end during use, but automatically closes to block any backflow when vacuum is released, thereby protecting the reusable vacuum line from contamination while maintaining system reusability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The check valve function is extracted as a separate, dedicated component rather than relying on the tortuous path design of the entire suctioning device. This extraction allows the main body to remain simple while the check valve specifically addresses the backflow problem through its one-way flow control mechanism.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If vacuum-release apertures are added to prevent high vacuum creation in the patient's mouth, then patient comfort is improved, but the ability to prevent contaminant backflow is reduced

Engineering Contradiction:
Improvepatient comfortVSAvoidcontaminant backflow
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The check valve acts as an intermediary that decouples the two functions: vacuum-release apertures can be added to the distal end for patient comfort during use, while the check valve in the proximal portion ensures that when vacuum is released, contaminants cannot backflow into the patient's mouth through the aperture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The suctioning device is segmented into a distal portion with vacuum-release apertures for patient comfort and a proximal portion with a check valve for contamination prevention. This segmentation allows both patient comfort features and backflow prevention to coexist without compromising either function.

Inventive Principle:
Principle #1Segmentation

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 effectively prevents contaminant backflow into the patient's mouth, reducing the risk of cross-contamination and ensuring a safer medical suctioning process by utilizing a valve flap mechanism and disposable covers to maintain sanitary conditions.

Implementation Method 1

the valve flap automatically disengages from the valve seat and allows fluid flow away from the patient's mouth

Methodology Applied
Scientific EffectVacuum pressure differential: Pressure Gradient

Implementation Method 2

The valve flap can be functionally flexible for movement within the housing away from the valve seat, and/or is biased toward the valve seat upon release of the vacuum

Methodology Applied
Scientific EffectElastic biasing: Elasticity

Data Source

PatentEP2150200B1Improved check valve for fluid injector
Publication Date: 2019.03.27 CROSSTEX INTERNATIONAL INC
  • EP2150200B1 patent drawingFigure 1~2
  • EP2150200B1 patent drawingFigure 3~4
  • EP2150200B1 patent drawingFigure 5~7

AI summary

A backflow-prevention system that substantially prevents contaminant backflow at a treatment site. The system includes a fluid ejector tube for insertion into the patient's mouth and for removal of fluids when a threshold vacuum pressure is applied. A backflow prevention device receives fluid from the fluid ejector tube and includes an internally positioned valve. The valve prevents contaminant backflow upon release of the vacuum pressure or a reduction in the vacuum pressure. Upon application of vacuum pressure, the valve moves into an open position to allow fluid flow away from the treatment site. The system can also include a disposable cover member that extends over at least portions of the fluid ejector tip, the backflow prevention device, and other features such as an ON/OFF valve assembly of a suction system. Similar principles of backflow prevention can be applied to fluid dispensers (e.g., liquid soap dispensers) wherein prevention of backflow of the fluid into the fluid storage container is necessary, in order for the dispenser to function properly.