Compact Automated Cell Counter with Linear Optical Path

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Solution Overview

Problem

Automated cell counting systems face limitations due to sampling error and require large instruments with a long optical path or large footprint to achieve accuracy, making them inconvenient for use in cell culture hoods.

Innovation Solution

A self-contained, compact automated cell counter with a linear optical path, digital imaging sensor, and achromat lenses, allowing for high-resolution imaging of a large field of view within a small footprint, and featuring autofocusing and automatic cell counting initiation upon sample insertion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a long optical path or large footprint is used to achieve acceptable accuracy in automated cell counting, then measurement precision is improved, but device complexity and space requirements increase

Engineering Contradiction:
Improvecell counting accuracyVSAvoidinstrument footprint
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent implements a folded optical path design where the light path is reflected back on itself multiple times within a compact housing. The optical components are arranged in a nested configuration, with the light source, sample chamber, and detector positioned to create a long effective optical path length (several centimeters) within a small footprint device. This nesting principle allows the instrument to achieve acceptable accuracy without requiring a large laboratory bench surface area.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If manual cell counting is performed with high dilution to reduce cell density, then ease of operation is improved, but measurement precision deteriorates due to decreased number of cells counted

Engineering Contradiction:
Improvecounting process simplicityVSAvoidcell counting accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the manual mechanical counting process with an automated digital imaging system. A camera captures images of cells in the chamber, and software automatically counts and analyzes the cells. This substitution eliminates the need for manual dilution adjustments and subjective counting, providing both ease of operation and improved measurement precision through objective, repeatable automated analysis of a fixed number of cells.

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

3Device complexity

If automated cell counting is performed with a limited imaging area, then device complexity is reduced, but measurement precision deteriorates due to increased sampling error

Engineering Contradiction:
Improveoptical system complexityVSAvoidcell counting accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements a motorized stage that automatically moves the sample chamber to capture multiple sequential images across the entire sample area. The system continuously scans through different regions of the chamber, accumulating cell count data from multiple fields of view. This continuous scanning approach increases the total number of cells counted while maintaining a simple fixed-field imaging system, thereby reducing sampling error without significantly increasing device complexity.

Inventive Principle:
Principle #20Continuity of useful 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

Enables highly accurate cell counting with minimal user intervention and a small footprint, reducing sampling errors and improving usability in limited spaces like cell culture hoods.

Implementation Method 1

optical components comprising a light source, a digital imaging sensor, and lenses positioned to direct light from said light source to said digital imaging sensor through said sample mount

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

lenses positioned to direct light from said light source to said digital imaging sensor through said sample mount

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 3

lenses positioned to direct light from said light source to said digital imaging sensor through said sample mount

Methodology Applied
Scientific EffectFocusing: Focusing

Data Source

PatentEP2473948B1Compact automated cell counter
Publication Date: 2019.08.21 BIO RAD LABORATORIES INC
  • EP2473948B1 patent drawingFigure 1
  • EP2473948B1 patent drawingFigure 2
  • EP2473948B1 patent drawingFigure 3

AI summary

Biological cells in a liquid suspension are counted in an automated cell counter that focuses an image of the suspension on a digital imaging sensor that contains at least 4,000,000 pixels each having an area of 2 x 2 µm or less and that images a field of view of at least 3 mm2. The sensor enables the counter to compress the optical components into an optical path of less than 20 cm in height when arranged vertically with no changes in direction of the optical path as a whole, and the entire instrument has a footprint of less than 300 cm2. Activation of the light source, automated focusing of the sensor image, and digital cell counting are all initiated by the simple insertion of the sample holder into the instrument. The suspension is placed in a sample chamber in the form of a slide that is shaped to ensure proper orientation of the slide in the cell counter.