Hollow Fiber Oxygenator with Variable Density Gradient
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Solution Overview
Problem
Existing blood oxygenator devices experience irregular blood flow across the cross-section of the hollow fiber package, leading to inferior mass transfer and potential thrombus formation due to consistent hollow fiber density, which results in disadvantaged flow regions.
Innovation Solution
The hollow fiber package is designed with locally varying fiber density, reducing flow resistance by increasing spacing between fibers in specific regions, particularly opposite blood inlet and outlet regions, creating a density gradient that enhances flow in previously disadvantaged areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If hollow fibers are equidistantly spaced throughout the package, then manufacturing is simplified, but blood flow becomes irregular and mass transfer efficiency decreases
Solution Approach 1:
The patent applies local quality by varying the spacing of hollow fibers in different regions of the package. Specifically, the first region (near blood inlet) has a first spacing between adjacent hollow fibers, while the second region (near blood outlet) has a second spacing that is greater than the first spacing. This non-uniform spacing creates a density gradient that optimizes blood flow distribution and mass transfer efficiency in different areas of the oxygenator.
2Device complexity
If hollow fiber density is uniform across the package, then structural simplicity is maintained, but flow resistance becomes uneven creating disadvantaged flow regions
Solution Approach 1:
The patent implements local quality by creating regions with different hollow fiber densities. The first region has a higher fiber density (smaller spacing) while the second region has a lower fiber density (larger spacing). This deliberate non-uniform density distribution ensures that blood flow is optimized throughout the package, preventing stagnant regions and reducing thrombus formation risk.
3Reliability
If spacing between hollow fibers is increased in specific regions, then flow resistance is reduced and blood flow is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by systematically varying the spacing parameter between hollow fibers in different regions. The spacing is changed from a first value in the first region to a second (greater) value in the second region. This controlled parameter variation optimizes blood flow characteristics while maintaining manufacturability through defined spacing patterns.
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 varying fiber density design improves blood flow uniformity across the cross-section, increasing flow in previously disadvantaged regions and reducing the risk of thrombus formation by reducing flow resistance.
Implementation Method 1
the permeation process causes oxygen from the gas/gas mixture to transfer through the hollow fiber walls into the blood
Implementation Method 2
creating a concentration gradient of the substances to be exchanged (O2 and CO2) between the blood and the gas/gas mixture
Implementation Method 3
carbon dioxide from the blood to transfer through the hollow fiber walls into the gas/gas mixture
Implementation Method 4
creating a concentration gradient of the substances to be exchanged (O2 and CO2) between the blood and the gas/gas mixture
Data Source
AI summary
A device for mass transfer between blood and a transfer medium, in particular a gas/gas mixture, includes a chamber through which blood can flow and in which a plurality of mass-permeable hollow fibers of at least one hollow fiber mat, in which the hollow fibers are held at a spacing by way of warp threads, are disposed in the form of a wound or folded hollow fiber package, wherein a transfer medium is able to flow through, and blood is able to flow around, the hollow fibers, and wherein the density of hollow fibers varies locally in the hollow fiber package in the cross-section perpendicular to length of the hollow fibers. Hollow fiber packages and methods of manufacturing thereof are provided in which the hollow fibers are held at a spacing by warp threads, in which the spacing between adjoining hollow fibers is locally increased, in particular compared to a predominantly equidistant spacing between the hollow fibers.