Microfluidic Flow Cytometer for Unprocessed Blood Cell Counting

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Solution Overview

Problem

Conventional blood cell measurement devices require complex processing steps like filtration and centrifugation, which can damage cells and are not suitable for point-of-care applications, and fail to provide a complete assessment of all cell species due to the need for extensive sample preparation.

Innovation Solution

A microfluidic flow-cytometer with a capillary pump-driven fluid conduit that allows for differential cell counting without separation or lysis, using a transparent microfluidic chip with a staining portion and detection portion for optical analysis, enabling unprocessed sample analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional processing steps (filtration, centrifugation, lysis) are used to separate cell types, then white blood cell detection is improved, but cell integrity is damaged and further analysis is prevented

Engineering Contradiction:
Improvewhite blood cell detectionVSAvoidcell integrity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent extracts only the necessary information (white blood cell count and differential) from the whole blood sample using optical detection, without extracting or removing other cell types through physical separation methods. This allows measurement of WBCs while preserving red blood cells and platelets for potential further analysis.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses optical detection as an intermediary method to identify and count white blood cells based on their unique light scattering properties and morphology, rather than using physical separation intermediaries like filters or centrifugal forces that would damage cell integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If extensive sample processing is performed to separate cell types, then diagnostic accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidprocessing steps
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical processing systems (filtration apparatus, centrifuges, lysis chambers) with a simple optical detection system that uses light scattering and absorption properties to differentiate and count cell types directly in the whole blood sample.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent enables the blood sample to be analyzed in its native state without requiring external processing intervention. The optical detection system directly measures cell properties in the unprocessed sample, making the sample itself the basis for analysis rather than requiring transformation through processing steps.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If conventional flow cytometry is used with sophisticated filtering and lysis, then cell type differentiation is improved, but measurement time increases

Engineering Contradiction:
Improvecell type differentiationVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary optical characterization of cells in the whole blood sample before any potential processing would be needed. By pre-measuring light scattering and absorption properties, the system can immediately differentiate cell types without requiring subsequent processing steps that would add time.

Inventive Principle:
Principle #10Preliminary action

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

Facilitates rapid, reliable, and complete cell counting with minimal sample preparation, preserving cell integrity for further analysis, suitable for point-of-care use.

Implementation Method 1

The device is a microfluidic flow-cytometer comprising a capillary pump-driven fluid conduit

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

The detection portion is configured to enable measurement of the sample fluid contained in the detection portion by optical means

Methodology Applied
Scientific EffectOptical absorption: Absorption (EM radiation)

Implementation Method 3

The fluid conduit comprises different portions along its length, including a staining portion and a detection portion

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP4220123B1Microfluidic device for cell count
Publication Date: 2025.11.05 BERNER FACHHOCHSCHULE
  • EP4220123B1 patent drawingFigure 1
  • EP4220123B1 patent drawingFigure 2~3
  • EP4220123B1 patent drawingFigure 4A~4B

AI summary

This invention concerns a microfluidic device and system for counting and/or measuring cells in a biological sample fluid. The device comprises a microfluidic chip with a fluid conduit having a staining portion and a detection portion, and a capillary pump fluidly connected to said conduit. The staining portion of the fluid conduit has an at least partially hydrophilic surface on which a staining agent and/or a labelling agent is disposed such as to contact the sample fluid when said sample fluid flows through the staining portion. The detection portion is configured to enable optical measurement of the sample fluid. The microfluidic system comprises the microfluidic device and an image acquisition apparatus. The invention also concerns a method for analysing a blood sample using the device.