Split Septum Fluid Shield for PIVC Blood Collection

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Solution Overview

Problem

Current PIVC blood draw systems face challenges with hemolysis and blood spillage due to high shear stress and pressure differentials, leading to compromised blood quality and inefficiencies.

Innovation Solution

A flow restriction device with a split septum and enclosure is integrated into the PIVC system, regulating blood flow rate and containing excess blood during disconnection, reducing shear stress and preventing spillage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a vacuum blood collection container is used to draw blood from the catheter, then blood collection efficiency is improved, but hemolysis occurs due to high shear stress and pressure differential

Engineering Contradiction:
Improveblood collection efficiencyVSAvoidhemolysis
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

A flow restriction device is introduced as an intermediary component between the vacuum blood collection container and the catheter. This device includes a flow restriction element that controls and limits the blood flow rate, preventing the high shear stress conditions that cause hemolysis while still allowing efficient blood collection through the vacuum mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flow restriction device changes the flow parameters by limiting the blood flow rate from the high-velocity state that causes hemolysis to a controlled, lower-velocity state. The device modifies the pressure differential and flow velocity parameters to prevent red blood cell damage while maintaining collection efficiency through the vacuum gradient.

Inventive Principle:
Principle #35Parameter changes

2Loss of time

If blood is drawn rapidly into the blood collection container, then collection time is reduced, but catheter tip collapse or vein collapse occurs

Engineering Contradiction:
Improvecollection timeVSAvoidcatheter function
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The flow restriction device serves as a mediator that decouples the vacuum force from the blood flow rate. It allows the vacuum to pull blood efficiently while the flow restriction element prevents excessive flow velocity that would cause catheter or vein collapse, thus maintaining system reliability during rapid collection.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flow restriction element is pre-configured to counteract the potential harmful effect of excessive blood flow velocity before it can cause catheter tip collapse or vein collapse. By limiting the flow rate in advance, the device prevents the collapse condition while still allowing efficient blood collection through the vacuum mechanism.

Inventive Principle:
Principle #9Preliminary anti-action

3Ease of operation

If the catheter is disconnected from the blood collection container after blood draw, then the blood collection process is completed, but blood spillage occurs

Engineering Contradiction:
Improvedisconnection capabilityVSAvoidblood spillage
Core Design Contradiction:
Ease of operationVSObject-generated harmful factors

Solution Approach 1:

A fluid shield assembly with a split septum is introduced as an intermediary sealing mechanism at the catheter connection point. This assembly allows the catheter to be disconnected from the blood collection container while the split septum seals around the catheter hub, preventing blood spillage during disconnection and maintaining ease of operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Adaptability or versatility

If a standard male luer connector is used on the catheter, then connection versatility is improved, but blood spillage occurs during connection and disconnection

Engineering Contradiction:
Improveconnection compatibilityVSAvoidblood spillage
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The fluid shield assembly with split septum is nested around the male luer connector. This nested structure allows the standard luer connector to maintain its connection versatility while the outer split septum provides a sealing barrier that prevents blood spillage during connection and disconnection operations.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The split septum acts as an intermediary sealing layer between the blood-containing system and the external environment during connector operations. It allows the standard luer connector to function with full versatility while preventing blood spillage through the sealing action of the split septum during connection and disconnection.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 device minimizes hemolysis and blood spillage by controlling flow resistance and containing blood within the system, ensuring safer and more efficient blood collection.

Implementation Method 1

the split septum comprising a flexible material with a centrally disposed slit

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

regulating blood flow rate and containing excess blood during disconnection, reducing shear stress

Methodology Applied
Scientific EffectFlow resistance: Drag

Implementation Method 3

a pressure in the vein is higher than a pressure in the blood collection container, which pushes blood into the blood collection container

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 4

red blood cells are in a high shear stress state and susceptible to hemolysis due to a high initial pressure differential

Methodology Applied
Scientific EffectShear stress: Shear Stress

Data Source

PatentEP4572669B1Fluid shield assemblies and flow restriction devices with fluid shield assemblies
Publication Date: 2025.11.05 CAREFUSION 303 INC
  • EP4572669B1 patent drawingFigure 1~2
  • EP4572669B1 patent drawingFigure 3~5
  • EP4572669B1 patent drawingFigure 6~9

AI summary

A flow restriction device includes a proximal housing configured to couple to a fluid collection device, a distal housing configured to couple to a catheter assembly, an intermediate housing interposed between the proximal housing and the distal housing and an internal fluid channel extending transversely therethrough. The flow restriction device also includes a fluid shield assembly having an enclosure coupled to an end of the distal housing and a split septum coupled to an end of the enclosure, the split septum comprising a flexible material with a centrally disposed slit. The fluid shield assembly provides for connection of a female connector to a male connector of the distal housing through the slit of the split septum, and to contain fluid within the enclosure and split septum upon disconnection and withdrawal of the female connector from the male connector. Blood collection systems and fluid shield assemblies are also provided.