Integrated Syringe Liquid Transfer for Infusion Line Flushing

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Solution Overview

Problem

Conventional infusion liquid containers fail to effectively prevent patients from receiving undiluted, high-concentration drugs, and existing systems lack efficient methods to flush the flow path between drug addition and administration.

Innovation Solution

A liquid transfer device with a trifurcated connector body, including an IV spike, vial adapter, and plunger mechanism, which allows for controlled mixing and flushing of medicated infusion liquids, ensuring complete dilution before administration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional infusion liquid container is used with manual drug addition, then the device complexity is low, but the reliability of preventing undiluted drug administration is insufficient

Engineering Contradiction:
Improveprevention of undiluted drug administrationVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the flushing mechanism and drug addition mechanism into a single integrated device. The plunger rod serves dual functions: it seals the vial adapter lumen during flushing and allows drug injection during mixing. This merging of functions improves reliability without proportionally increasing device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The device performs a preliminary flushing action before drug administration by advancing the plunger rod to seal the vial adapter lumen and flush the flow path. This preliminary action ensures the flow path is clear and prevents undiluted drug administration, thereby improving reliability before the actual drug mixing occurs.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If a flushing mechanism is added to flush the flow path, then the reliability of drug dilution is improved, but the device complexity increases

Engineering Contradiction:
Improvecomplete mixing and flushing of drugsVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The plunger rod is designed with universal functionality: it seals the vial adapter lumen during flushing, allows drug injection during mixing, and controls fluid flow throughout the process. This multi-functionality achieves complete mixing and flushing reliability while minimizing the addition of separate components, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The plunger rod is nested within the barrel and works in conjunction with the internal chamber. The sealing element on the plunger rod nests within the vial adapter lumen during the flushing action. This nested arrangement achieves effective flushing and mixing without requiring separate external flushing mechanisms, thus improving reliability while controlling device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If the plunger rod seals the vial adapter lumen during flushing, then the completeness of drug mixing is improved, but the ease of operation decreases

Engineering Contradiction:
Improvecomplete mixing of medicamentVSAvoidease of operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The device utilizes the infusion liquid pressure from the infusion container to automatically perform the flushing action when the plunger rod seals the vial adapter lumen. The system self-regulates the flushing process without requiring additional manual operations, thereby maintaining ease of operation while achieving complete drug mixing through the sealing action.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The plunger rod is designed to be movable between different positions: retracted for drug injection, advanced for sealing and flushing, and intermediate positions for controlled mixing. This dynamic positioning allows the operator to easily transition between operations while ensuring complete mixing when the sealing position is reached, thus maintaining ease of operation despite the sealing function.

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

Ensures complete mixing and flushing of drugs with infusion liquids, preventing undiluted drug administration and enhancing patient safety by ensuring all medicament is fully mixed and administered in a diluted form.

Implementation Method 1

In an advanced position of the plunger, the plunger rod seals off the vial adapter lumen from fluid communication with the IV spike lumen and the internal chamber of the barrel is in fluid communication with the IV spike lumen and the first aperture of the IV spike

Methodology Applied
Scientific EffectSealing:

Implementation Method 2

The plunger rod and the IV spike lumen define a fluid-flow pathway therebetween, the fluid-flow pathway being sealed off from the vial adapter lumen

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 3

combining the medicament additive contained within the vial with the infusion liquid within the infusion liquid container via fluid communication between the vial adapter lumen, the IV spike lumen and the first aperture of the IV spike when the plunger is in the retracted position, to form a medicated infusion liquid

Methodology Applied
Scientific EffectMixing and dilution:

Data Source

PatentEP3952952B1Liquid transfer device with integrated syringe
Publication Date: 2025.11.19 WEST PHARM SERVICES IL LTD
  • EP3952952B1 patent drawingFigure 1A~1D
  • EP3952952B1 patent drawingFigure 2
  • EP3952952B1 patent drawingFigure 3A

AI summary

A liquid transfer device is provided for mixing a medicament additive contained within a vial with an infusion liquid contained within an infusion liquid container to form a medicated infusion liquid. The liquid transfer device includes a trifurcated connector body defining a barrel at a first end thereof, an IV spike at a second end thereof and a vial adapter lumen with a vial adapter secured thereto at a third end thereof. A plunger having an IV port is slidably engaged with the barrel to form a syringe integrated with the device. The syringe enables the device to flush out the flow path between the IV port and the IV spike connected to the medicated infusion liquid, and any residual unmixed medicament additive therein, after combining the medicament additive with the infusion liquid.