Stacked Plasma Separation Device with Capillary Absorption

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Solution Overview

Problem

Current methods for separating plasma from whole blood samples are inefficient and require sophisticated instruments for shipping, which can be costly and risky for transporting infectious materials.

Innovation Solution

A device comprising a stacked structure with a separating member and an absorptive member, where the separating member uses a depth filter element and size-exclusion element to isolate plasma from blood cells, and the absorptive member absorbs and dries the plasma for safe transport, allowing for capillary force-driven separation and easy removal without damaging the absorptive member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional plasma separation methods are used, then plasma can be separated from whole blood, but sophisticated instruments are required for shipping which increases cost and risk for transporting infectious materials

Engineering Contradiction:
Improvesafe transport of plasmaVSAvoidsophisticated instruments required
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The device is divided into distinct segments: a separating member with filter elements and an absorptive member. This segmentation allows the plasma separation and absorption functions to be performed by simple, disposable components rather than complex instruments, resolving the contradiction between reliability and device complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs a disposable device that performs plasma separation and absorption in a single use. This eliminates the need for expensive, sophisticated shipping instruments by providing a complete, self-contained solution that can be discarded after use, reducing both cost and risk for transporting infectious materials.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Productivity

If a depth filter element is used to slow blood cell flow, then plasma separation efficiency is improved, but the size-exclusion element may become clogged

Engineering Contradiction:
Improveplasma separation efficiencyVSAvoidclogging of size-exclusion element
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The depth filter element acts as a preliminary filtering stage that slows down and pre-filters the blood sample before it reaches the size-exclusion element. This preliminary action prevents large particles and aggregates from reaching the size-exclusion element, thereby preventing clogging while maintaining efficient plasma separation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The depth filter element serves as an intermediary component between the sample inlet and the size-exclusion element. It mediates the flow of blood by slowing it down and removing potential clogging agents before the fluid reaches the more sensitive size-exclusion element, thus protecting it from clogging.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If the separating member and absorptive member are permanently fixed together, then structural stability is improved, but the absorptive member cannot be easily removed for analysis

Engineering Contradiction:
Improvestructural stabilityVSAvoideasy removal of absorptive member
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The connection between the separating member and absorptive member is made dynamic rather than static. The adhesive element provides stable bonding during the plasma separation process, but allows for easy separation when needed. This dynamic characteristic resolves the contradiction between maintaining structural stability during operation and enabling easy removal for analysis.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The device is designed so that the absorptive member can be easily separated from the separating member after plasma absorption. This allows the absorptive member containing the plasma to be recovered for analysis while the separating member can be discarded. This approach maintains structural stability during use while enabling easy recovery of the valuable plasma sample.

Inventive Principle:
Principle #34Discarding and recovering

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

Enables efficient and cost-effective separation and transport of plasma, ensuring safe handling and analysis by preventing contamination and maintaining infectious virus particles' inactivity in a dried state, facilitating plasma analysis at dedicated sites.

Implementation Method 1

the separating member is adapted to permit the passage of plasma and plasma macromolecules but to inhibit the passage of blood cells so as to separate the plasma from the cells

Methodology Applied
Scientific EffectSize-exclusion: Molecular Sieve

Implementation Method 2

the depth filter element slows the flow of blood cells relative to that of the plasma and the size-exclusion element permits plasma flow and blocks the passage of cellular blood components... enables a lateral diffusion of the various components of blood

Methodology Applied
Scientific EffectLateral diffusion: Diffusion

Implementation Method 3

The absorptive member is adapted for absorbing plasma which is or can be brought in fluid communication with the separating member... by means of capillary pressure generated by the absorptive member

Methodology Applied
Scientific EffectCapillary pressure: Capillary Action

Implementation Method 4

the absorptive member is adapted for drying plasma contained therein so that the absorptive member may contain plasma in a wet or dried condition

Methodology Applied
Scientific EffectDrying: Desiccation

Data Source

PatentEP2375249B1Devices and process for separating plasma from a blood sample
Publication Date: 2019.12.25 F HOFFMANN LA ROCHE & CO AG
  • EP2375249B1 patent drawingFigure 1~2
  • EP2375249B1 patent drawingFigure 3

AI summary

The present invention pertains to a device for separating plasma from a blood sample comprising a stacked structure which is provided with a first portion including a separating member having a first surface for applying or receiving the blood sample, wherein the separating member is adapted to permit the passage of plasma but to inhibit the passage of cells, and a second portion including an absorptive member for absorbing the plasma, which has a second surface in contact with the separating member for receiving the plasma, wherein the absorptive member is adapted to generate a capillary pressure so as to draw plasma from the separating member to the absorptive member. The first portion is fixed to the backing member in a manner to be removed without destroying the absorptive member. The absorptive member is fixed to the backing member in a manner to be removed without destroying the absorptive member. It further relates to a device wherein the first portion is fixed to the absorptive member in a manner to be removed without destroying the absorptive member. It further relates to a process for separating plasma from a blood sample comprising the following steps of: applying the blood sample to a plasma separating member; drawing said blood sample through said separating member to a plasma absorbing member backed by a backing member; non-destructively removing said absorptive member from said separating member and non-destructively removing said absorptive member from said backing member.