Hemolysis-Reduction Connector Serpentine Channel
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current blood draw methods using peripheral intravenous catheters (PIVCs) often result in hemolysis due to high shear stress on red blood cells caused by the initial pressure differential between the vein and the blood collection container.
Innovation Solution
A flow restriction device is introduced, which includes a housing with a cavity and an insert body with a serpentine channel. This device is attached to the PIVC and regulates the flow rate of blood, reducing the shear stress on red blood cells and minimizing hemolysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a vacuum blood collection container is coupled to the catheter for blood withdrawal, then blood can be drawn into the container, but red blood cells experience high shear stress causing hemolysis
Solution Approach 1:
A flow restriction device with a tortuous channel is introduced as an intermediary component between the catheter and the vacuum blood collection container. This device creates a controlled flow path that reduces the pressure differential and shear stress on red blood cells while still allowing blood to be drawn into the container. The tortuous channel design with multiple bends and a length significantly greater than the straight-line distance between endpoints acts as a flow dampener, protecting blood cells from hemolysis caused by the vacuum pressure.
Solution Approach 2:
The flow restriction device changes the flow parameters of blood by creating a tortuous path that increases flow path length and reduces flow velocity. The channel has a length of at least 5 times the straight-line distance between its endpoints, with multiple bends that create turbulence and reduce the linear velocity of blood flow. This parameter change reduces the shear stress on red blood cells from the high-velocity direct flow to a lower-velocity tortuous flow, preventing hemolysis while maintaining blood collection functionality.
2Speed
If a high pressure differential is used to draw blood quickly, then blood collection speed increases, but catheter tip collapse or vein collapse occurs
Solution Approach 1:
The flow restriction device serves as a mediator that decouples the vacuum pressure from the catheter tip. By placing the flow restriction device between the vacuum source and the catheter, the high pressure differential is applied across the restriction device rather than directly at the catheter tip. This protects the catheter and vein from collapse while still enabling blood collection through the controlled tortuous flow path.
Solution Approach 2:
The tortuous channel in the flow restriction device uses curvature and bends to reduce linear flow velocity. The channel contains multiple bends with radii of curvature that create a non-linear flow path, causing the blood to follow a curved trajectory rather than moving in a straight line. This curvature reduces the linear velocity and shear stress on the blood and catheter wall, preventing catheter tip collapse and vein collapse while maintaining effective blood collection.
3Loss of energy
If a straight channel is used in the connector, then fluid flow resistance is low, but shear stress on red blood cells remains high causing hemolysis
Solution Approach 1:
The flow restriction device replaces a straight channel with a tortuous channel containing multiple bends. The channel has a length of at least 5 times the straight-line distance between its endpoints, with bends that create a non-linear flow path. This curvature increases the flow path length and reduces linear flow velocity, thereby reducing shear stress on red blood cells and preventing hemolysis, while still maintaining acceptable fluid flow resistance for blood collection.
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 flow restriction device effectively reduces the risk of hemolysis during blood collection by decreasing the shear stress on red blood cells, while also being compatible with existing PIVC products and blood collection devices, thus minimizing disruptions to clinical operations.
Implementation Method 1
a channel defined on the outer surface, wherein the channel extends between the first and second ends, the channel comprising a first portion that extends in a first direction away from the longitudinal axis and a second portion that extends in a second direction toward the longitudinal axis
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A flow restriction device may include a housing and an insert body. The housing defines a first lumen, a second lumen, and a cavity disposed between the first lumen and the second lumen. The insert body can be disposed within the cavity. The insert body includes a first end, a second end, a longitudinal axis extending through the first and second ends, an outer surface, and a channel. The channel is defined on the outer surface. The channel extends between the first and second ends. The channel includes a first portion that extends in a first direction away from the longitudinal axis and a second portion that extends in a second direction toward the longitudinal axis. The channel and an inner surface of the cavity define a fluid passage in fluid communication with the first lumen and the second lumen.