Co-injection Member Vortex Flow Design for Dialysis Blood Circuit

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Solution Overview

Problem

Existing co-injection members for blood circuits in dialysis treatments face issues with liquid congestion and inefficient blood collection or injection due to interference with projections and insufficient vortex formation, which can affect blood cell components.

Innovation Solution

A co-injection member design featuring an internal flow route with an inlet and outlet flow route that gradually decrease in diameter towards the center, generating a vortex to prevent congestion, and a rubber member with a slit for smooth insertion of puncture tubes or syringes, ensuring reliable liquid collection and injection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a projection is formed on the bottom surface in a central portion of the internal flow route to prevent congestion, then congestion prevention is improved, but the distal end of the puncture tube or syringe interferes with the projection, causing unsatisfactory blood collection or drug injection

Engineering Contradiction:
Improvecongestion preventionVSAvoidblood collection and drug injection
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The projection that causes interference is removed from the central portion of the internal flow route bottom surface. Instead, the patent forms an inclined surface on the side wall of the internal flow route that extends from the opening toward the bottom surface, eliminating the interfering projection while maintaining congestion prevention through the inclined surface geometry

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of adding a projection to the bottom surface to prevent congestion, the patent inverts the approach by forming an inclined surface on the side wall that slopes downward toward the opening. This inverted geometry prevents congestion through flow direction control while avoiding interference with injection operations

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If the inlet flow route and outlet flow route are formed toward a position shifted from the center of the internal flow route to prevent congestion, then congestion inhibition is improved to some degree, but flow velocity of the blood is not changed, resulting in insufficient effect

Engineering Contradiction:
Improvecongestion inhibitionVSAvoidflow velocity change
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the geometric parameters of the flow route by forming an inclined surface on the side wall that extends from the opening toward the bottom surface. This parameter change creates a slope that actively directs blood flow and increases flow velocity, rather than merely shifting route positions as in the prior art

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The inclined surface creates a curved flow path that guides blood flow smoothly from the opening toward the bottom surface and outlet. This curved geometry promotes vortex formation and maintains higher flow velocities compared to straight or shifted route configurations

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of operation

If the distal end of the puncture tube or syringe is inserted into the slit of the co-injection member, then blood collection or drug injection can be performed, but the distal end interferes with the projection, causing unsatisfactory collection or injection

Engineering Contradiction:
Improveblood collection and drug injection capabilityVSAvoidcollection and injection effectiveness
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The interfering projection is removed from the internal flow route structure. The patent replaces it with an inclined surface formed on the side wall, which eliminates the physical barrier that prevented complete insertion of the puncture tube or syringe distal end into the internal flow route

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The inclined surface is pre-formed on the side wall to guide the distal end of the puncture tube or syringe smoothly toward the bottom surface and outlet. This preliminary geometric preparation ensures that the injection tool can reach the optimal position without interference, improving both ease of operation and effectiveness

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 design allows for smooth liquid collection and injection while preventing congestion in the internal flow route, ensuring safe blood collection and drug injection, and maintaining blood cell integrity by generating a vortex and reducing flow velocity.

Implementation Method 1

the inlet flow route extends while a diameter thereof gradually decreases toward a position shifted from the center of the internal flow route... generating a vortex to prevent congestion

Methodology Applied
Scientific EffectVortex: Vortex Ring

Data Source

PatentEP3081248B1Co-injection member
Publication Date: 2019.11.20 NIKKISO CO LTD
  • EP3081248B1 patent drawingFigure 1
  • EP3081248B1 patent drawingFigure 2~4
  • EP3081248B1 patent drawingFigure 5~7

AI summary

An object is to provide a co-injection member which can smoothly collect a liquid of an internal flow route, which can smoothly inject a liquid into the internal flow route, and which can reliably prevent congestion of the liquid in the internal flow route. A co-injection member (1) includes a main body (2) that can be connected to a blood circuit through which blood is circulated, an internal flow route (α) that is formed inside the main body (2), and that can circulate the liquid of the blood circuit, an inlet flow route (A) that is formed inside the main body (2), and that introduces the blood into the internal flow route (α), an outlet flow route (B) that is formed inside the main body (2), and that can discharge the blood of the internal flow route (α), and a rubber member (4) that is attached to an opening (2c) formed in the main body (2), and that separates the inside and the outside of the internal flow route (α) from each other. The co-injection member (1) can collect the blood of the internal flow route (α) and can inject the other liquid into the internal flow route (α) via the rubber member (4). The inlet flow route (A) extends while a diameter thereof gradually decreases toward a position shifted from a center (P) of the internal flow route (α).