Spinning Membrane Separator Priming via Inverted Flow
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Solution Overview
Problem
Existing methods for priming spinning membrane separators in blood processing systems are not effective in consistently priming the entire membrane surface, leading to inefficiencies and potential membrane fouling.
Innovation Solution
A two-stage priming procedure is implemented, where a priming fluid is first conveyed into the spinning membrane separator via the filtrate outlet port to push air out through the inlet and retentate ports, followed by a second stage where the priming fluid is introduced via the inlet port to clear residual air from the annulus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional priming methods are used (introducing priming fluid via inlet port), then the priming process is simple, but air trapped behind the membrane is not effectively removed resulting in only 90% priming efficiency
Solution Approach 1:
The patent introduces priming fluid through the filtrate outlet port rather than the conventional inlet port, reversing the typical flow direction. This inversion allows the priming fluid to effectively displace air from the membrane surface outward through the rotor, achieving over 95% priming efficiency by addressing the root cause of air entrapment behind the membrane
Solution Approach 2:
The priming process is divided into distinct stages: first introducing priming fluid through the filtrate outlet port to remove air from the membrane surface, then introducing additional priming fluid through the inlet port to clear remaining air from the annulus. This segmentation allows each stage to address specific air entrapment locations, ensuring complete priming while maintaining procedural clarity
2Reliability
If air bubbles are not removed from behind the membrane, then the priming process is faster, but membrane fouling occurs during separation
Solution Approach 1:
The patent performs air removal from behind the membrane as a preliminary action before the actual separation process begins. By introducing priming fluid through the filtrate outlet port first, air is displaced from the critical membrane surface area in advance, preventing fouling during separation and ensuring optimal membrane performance from the start of processing
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
This approach consistently removes over 95% of air trapped behind the membrane, improving membrane priming efficiency and reducing the risk of fouling compared to conventional methods which may only achieve 90% priming.
Implementation Method 1
Spinning membrane separators have been found to provide excellent plasma filtration rates or separation efficiencies, due primarily to the unique flow patterns ('Taylor vortices') induced in the annulus between the spinning rotor and the housing. The Taylor vortices help to keep the blood cells from depositing on and fouling or clogging the membrane.
Implementation Method 2
The fluid moves along the longitudinal axis of the housing toward an exit region, with the filtrate (e.g., plasma) passing through the membrane and out of the housing via an outlet port aligned with the rotational axis of the rotor. The remaining fluid components or retentate (which will be cellular blood components, in the case of blood or platelet-rich plasma being processed by the spinning membrane separator) move to the exit region between the rotor and the housing
Data Source
Figure 1A~1C
Figure 2A~2D
Figure 3
AI summary
During a first stage of a priming procedure, a priming fluid is conveyed into a spinning membrane separator via a filtrate outlet port so as to convey air out of the spinning membrane separator via an inlet port and a retentate outlet port of the spinning membrane separator. During an optional second stage of the priming procedure, the priming fluid is conveyed into the spinning membrane separator via the inlet port so as to convey air out of the spinning membrane separator via the retentate outlet port. A rotor positioned within a housing of the spinning membrane separator may be rotated with respect to the housing during the first and second stages to force air from within the rotor into an annulus defined between the rotor and the housing for more complete priming of the spinning membrane separator.