Leukocyte-Removing Filter With Volume Restriction Boards
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional leukocyte-removing filters face challenges when used at high flow rates, including filter breakage and decreased leukocyte removal capability due to nonuniform blood flow and adhesion issues, which hinder efficient filtration and effective utilization of the filtration area.
Innovation Solution
A leukocyte-removing filter with a flat and flexible container, paired with volume restriction boards that sandwich the filter to control expansion, and a sheet-like leukocyte-removing-filter material with specific thickness and air permeability pressure drop, ensuring efficient leukocyte removal and effective filtration area utilization at high flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If blood is filtered at high flow rate by pressurizing with a pump, then filtration speed is improved, but the flexible container expands like a balloon causing nonuniform blood flow and potential filter breakage
Solution Approach 1:
The patent uses a flexible container made of elastic material that can expand and contract. During filtration, the container expands to accommodate blood volume, then contracts to maintain uniform pressure distribution, preventing both filter breakage and nonuniform flow. This flexible shell approach allows the system to handle high flow rates while maintaining structural integrity.
Solution Approach 2:
The patent changes the physical state of the container from rigid to flexible, allowing volume and shape parameters to dynamic adjust during operation. The container's flexibility enables it to absorb pressure variations and maintain uniform blood flow distribution even at high flow rates, preventing filter breakage while maintaining productivity.
2Strength
If a hard container is used in the leukocyte-removing filter, then structural strength is improved, but steam permeability is lost making high-pressure vapor sterilization difficult
Solution Approach 1:
The patent replaces hard containers with flexible containers made of elastic materials that are both sterilizable and structurally sound. The flexible material allows steam to penetrate during high-pressure vapor sterilization while maintaining sufficient strength to withstand filtration pressures, resolving the contradiction between hardness and sterilization capability.
3Productivity
If the flexible container is not restricted in volume, then filtration efficiency is improved, but the container expands excessively causing nonuniform blood flow and potential rupture
Solution Approach 1:
The patent employs a flexible container that dynamically adjusts its volume during filtration. The container expands to accommodate blood volume for efficient filtration, then contracts to maintain uniform pressure distribution, preventing both filter breakage and nonuniform flow. This flexible shell approach allows the system to handle high flow rates while maintaining structural integrity.
Solution Approach 2:
The patent introduces dynamic volume adjustment capability to the container system. The container can change its volume in response to blood flow conditions, expanding when needed for efficient filtration and contracting to maintain uniform pressure distribution, thereby preventing both filter breakage and nonuniform flow.
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 configuration enhances leukocyte removal capability and effective filtration area utilization, preventing filter breakage and nonuniform flow, allowing for efficient filtration of blood components at high flow rates while maintaining filter integrity.
Implementation Method 1
a filter method in which leukocytes are removed by using a filter material comprising a porous element such as fiber material or porous material having continuous pores
Implementation Method 2
a volume restriction board is used to prevent swelling of the leukocyte-removing filter by using the leukocyte-removing filter comprising a flat and flexible container when filtering blood or blood components at a high flow rate
Data Source
AI summary
The method comprises providing a leukocyte-removing filter having a thickness of 9.0 mm to 9.4 mm, an air permeability pressure drop of 300 Pa to 700 Pa, and effective filtration area of 50 cm2 to 70 cm2 which comprises a flat and flexible container having an inlet port and an outlet port and a sheet-like leukocyte-removing-filter material with a thickness of 8.2 mm to 8.6 mm disposed to divide the container into an inlet-port side chamber and an outlet-port side chamber, providing a pair of volume restriction boards disposed outside of the inlet port side external surface and the outlet port side external surface of the flexible container, having the distance between the volume restriction boards at the portion where the volume restriction boards facing each other sandwich the leukocyte-removing filter being in a range from [thickness of leukocyte-removing filter+0.5 mm] to [thickness of leukocyte-removing filter+2.5 mm], and filtering blood or blood components through the leukocyte-removing filter under a pressure of 30 kPa to 50 kPa while restraining expansion of the flexible container occurring during filtration by means of the volume restriction boards.