Needleless IV Injection Port Sealing Mechanism

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Solution Overview

Problem

Conventional needleless injection ports have led to an increase in catheter-related bloodstream infections (CR-BSIs) and intraluminal thrombotic catheter occlusions, compromising patient safety and care.

Innovation Solution

The proposed injection port assembly features a resilient barrier with a specific internal cavity design and a hollow cannula with lateral outlet windows, which provides an interference fit to enhance sealing and reduce fluid reflux, thereby minimizing contamination and occlusions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional needleless injection ports are used, then accidental needlestick injuries are prevented, but catheter-related bloodstream infections and intraluminal thrombotic catheter occlusions increase

Engineering Contradiction:
Improveaccidental needlestick injuriesVSAvoidcatheter-related bloodstream infections and intraluminal thrombotic catheter occlusions
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The injection port is divided into distinct functional segments: a catheter interface portion, a resilient barrier portion with internal cavity, and a syringe interface portion. This segmentation allows each component to perform its specific function optimally - the barrier seals against the catheter while the cannula directs fluid flow, preventing both needlestick injuries and catheter infections

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The resilient barrier with internal cavity acts as an intermediary between the catheter and the syringe. It provides a sealed interface that prevents contamination while allowing controlled fluid access, eliminating the need for steel needles and preventing catheter-related infections

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If conventional resilient barrier designs are used, then fluid flow is permitted when needed, but fluid reflux occurs causing contamination and occlusions

Engineering Contradiction:
Improvefluid deliveryVSAvoidfluid reflux
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

The internal cavity of the resilient barrier creates a three-dimensional fluid pathway that directs fluid flow in a specific direction. The cavity's geometry establishes a preferred flow path from the catheter through the barrier to the syringe interface, preventing reflux by utilizing spatial dimensionality to control fluid direction

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The resilient barrier is pre-configured with its internal cavity structure before use. When the syringe interface is engaged, the barrier is preliminarily positioned to establish the correct fluid pathway orientation, ensuring that fluid flows in the intended direction and preventing reflux before the procedure begins

Inventive Principle:
Principle #10Preliminary action

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 improved design significantly reduces the risk of CR-BSIs and intraluminal thrombotic catheter occlusions by enhancing the sealing integrity and reducing fluid reflux, thus ensuring better patient safety and care.

Implementation Method 1

A resilient barrier is configured to be received within the body and is compressible from a less compressed first position in which fluid flow through the injection port assembly is blocked, to a more compressed second position in which fluid flow through the injection port assembly is permitted

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The cannula distal end portion both distally and proximally of the lateral outlet window has a cannula distal end portion outside diameter sufficiently greater than the cavity sealing portion inside diameter such that when the cannula is received in the resilient barrier with the cannula nose received in the cavity nose portion there is an interference fit between the cannula and the resilient barrier extending along the lateral outlet window

Methodology Applied
Scientific EffectInterference fit:

Data Source

PatentEP3912672B1Needleless iv injection port
Publication Date: 2025.05.21 FRESENIUS KABI DEUTSCHLAND GMBH
  • EP3912672B1 patent drawingFigure 1
  • EP3912672B1 patent drawingFigure 2~4
  • EP3912672B1 patent drawingFigure 5~7

AI summary

A needleless injection port assembly includes first and second body parts and a resilient barrier received within the body. A cannula attached to the first body part is received within an internal cavity of the resilient barrier. The resilient barrier is moveable between a less axially compressed first position in which fluid flow through the injection port assembly is prevented and a more axially compressed second position in which fluid flow through the assembly is allowed. An interference fit is provided between the resilient barrier and the cannula to seal against fluid flow through the cannula when the resilient barrier is in the first position. The cannula has an internal fluid passageway with a non-circular cross section providing increased fluid flow.