Flow Cell Channel Geometry for Stable Imaging and Light Collection

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Solution Overview

Problem

Existing flow cells in flow cytometers face a trade-off between fluidics stability and optical collection efficiency, with unity aspect ratios maximizing fluidics stability but reducing optical collection efficiency, while higher aspect ratios improve optical collection but interfere with imaging.

Innovation Solution

Flow cells with a rectangular cross-section and aspect ratio ranging from 1.0 to 1.4, optimized for both fluidics stability and optical collection efficiency, incorporating anti-reflective coatings and specific dimensions to enhance performance across different operating modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a unity aspect ratio flow channel is used, then fluidics stability is maximized, but optical collection efficiency is highly reduced due to scatter and clipping of collected light

Engineering Contradiction:
Improvefluidics stabilityVSAvoidoptical collection efficiency
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by modifying the aspect ratio of the flow channel from unity (1:1) to a optimized range of 1.0 to 1.4. This parameter adjustment allows the flow channel to maintain fluidics stability while reducing optical scattering and clipping losses, thereby improving optical collection efficiency without sacrificing flow stability.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If an aspect ratio of 2.4 is used, then optical collection efficiency is maximized, but imaging optical qualities are interfered with

Engineering Contradiction:
Improveoptical collection efficiencyVSAvoidimaging optical quality
Core Design Contradiction:
Loss of energyVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by adjusting the aspect ratio from the conventional 2.4 to an optimized range of 1.0 to 1.4. This modification maintains imaging optical qualities by preventing excessive stream ellipse stretching while still achieving good optical collection efficiency, thus resolving the contradiction between these two performance aspects.

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If a rectangular channel with high aspect ratio is used, then optical collection efficiency is improved, but the core stream ellipse gets stretched interfering with imaging

Engineering Contradiction:
Improveoptical collection efficiencyVSAvoidcore stream ellipse shape
Core Design Contradiction:
Loss of energyVSShape

Solution Approach 1:

The patent applies parameter changes by limiting the aspect ratio to the range of 1.0 to 1.4, which prevents excessive stretching of the core stream ellipse while maintaining adequate optical collection efficiency. This parameter control ensures that the stream shape remains suitable for imaging applications.

Inventive Principle:
Principle #35Parameter changes

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 optimized flow cells achieve high performance in both imaging and non-imaging modes with improved fluidic stability and optical collection efficiency, balancing scatter and clipping issues.

Implementation Method 1

a cuvette configured to transport particles in a flow stream, the cuvette having a flow channel with a rectangular cross-section and an aspect ratio ranging from 1.0 to 1.4

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

incorporating anti-reflective coatings and specific dimensions to enhance performance across different operating modes

Methodology Applied
Scientific EffectAnti-reflective coating: Anti-Reflective Coating

Implementation Method 3

the flow stream is irradiated with light. Variations in the materials in the flow stream, such as morphologies or the presence of fluorescent labels, may cause variations in the observed light

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 4

the light emitted from fluorescent molecules in one or more detectors that measure signal over a range of spectral wavelengths

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP4644862A1Flow cells having an optimized flow channel geometry, flow cytometers including the same, and methods of use thereof
Publication Date: 2025.11.05 BECTON DICKINSON & CO
  • EP4644862A1 patent drawingFigure 1A
  • EP4644862A1 patent drawingFigure 1B
  • EP4644862A1 patent drawingFigure 1C

AI summary

Flow cells having an optimized flow channel geometry are provided. Flow cells of interest include a cuvette configured to transport particles in a flow stream, the cuvette having a flow channel with a rectangular cross-section and an aspect ratio ranging from 1.0 to 1.4. Flow cytometers having the subject flow cells and methods of use and assembly thereof are also provided.