Contact Imaging Micrometric Particle Detection via Evaporation

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Solution Overview

Problem

Current optical imaging techniques for biological diagnosis, such as flow cytometry and fluorescence molecular imaging, are expensive, complex, and invasive, with limited solid scanning angles and low detection efficiency, especially when using low-sensitivity sensors.

Innovation Solution

A contact imaging method that detects micrometric particles by allowing a drop of liquid containing the particles to evaporate, increasing the signal-to-noise ratio by forming a residual film that acts as a microlens, allowing detection with low-sensitivity sensors and enabling three-dimensional reconstruction of particle distributions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If flow cytometry or fluorescence molecular imaging is used for detection, then detection sensitivity is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection sensitivityVSAvoidinstrumentation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the detection function from complex optical systems and implements it using a simple CMOS sensor array in direct contact with the sample. By removing magnification optics and complex illumination systems, the invention achieves particle detection without requiring flow cytometry or fluorescence imaging equipment, thus reducing device complexity while maintaining detection capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a low-cost CMOS sensor array instead of expensive specialized sensors. The sensor is placed in direct contact with the sample on a transparent substrate, eliminating the need for costly optical components. This approach uses inexpensive, readily available technology to achieve the detection function that previously required expensive instrumentation

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

2Measurement precision

If fluorescence imaging with filters is used to separate excitation and emission energy, then detection specificity is improved, but optical system complexity increases

Engineering Contradiction:
Improvedetection specificityVSAvoidoptical system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent removes the complex optical filtering system entirely and replaces it with direct optical detection. Instead of using filters to separate excitation and emission wavelengths, the invention detects particles directly through their light scattering properties using a simple CMOS sensor, eliminating the need for complex optical path management

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent substitutes the mechanical/optical filtering system with a direct electronic detection approach. Rather than using physical filters to separate wavelengths, the system uses image processing and pattern recognition algorithms to identify particles, replacing physical optical components with computational methods

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

3Device complexity

If contact imaging without magnification optics is used, then device simplicity is improved, but detection precision deteriorates

Engineering Contradiction:
Improvedevice simplicityVSAvoiddetection precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transitions from traditional two-dimensional imaging to three-dimensional detection by placing the sensor array in direct contact with the sample on a transparent substrate. This allows detection at multiple depths and creates a third dimension for particle identification, enabling precise detection without magnification optics through volumetric sampling

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the detection parameters by using the CMOS sensor's native pixel array directly for particle detection without optical magnification. By adjusting the sensor's readout parameters and using image processing algorithms, the system achieves precise particle detection through changes in detection parameters rather than optical magnification

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If standard CMOS sensors are used for particle detection, then cost is reduced, but signal-to-noise ratio deteriorates

Engineering Contradiction:
ImprovecostVSAvoidsignal-to-noise ratio
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent performs preliminary concentration of particles through evaporation of the liquid medium before detection. By allowing the liquid to evaporate and concentrate the particles in a smaller volume, the system enhances the signal-to-noise ratio for subsequent detection by the CMOS sensor, enabling standard sensors to achieve adequate detection precision

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical state of the sample from liquid to concentrated residue through evaporation. This parameter change concentrates the particles and enhances their optical signal, allowing standard CMOS sensors to detect them with acceptable signal-to-noise ratios without requiring high-sensitivity sensors

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

Significantly enhances the signal-to-noise ratio and detection efficiency, allowing for clear detection of particles without the need for high-sensitivity sensors, and provides a non-invasive, cost-effective alternative to traditional methods.

Implementation Method 1

The method consists essentially in carrying out the measurement or measurements during or after the phase of evaporation of the drop of liquid in which the micrometric particles (bacteria, cells, beads, etc.) to be detected are found.

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

forming a residual film that acts as a microlens, allowing detection with low-sensitivity sensors

Methodology Applied
Scientific EffectMicrolens effect: Lens

Data Source

PatentEP2488847B1Method for optically detecting dissolved micrometric objects
Publication Date: 2017.11.15 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP2488847B1 patent drawingFigure 1~2
  • EP2488847B1 patent drawingFigure 3~4
  • EP2488847B1 patent drawingFigure 5

AI summary

The general field of the invention is that of contact-imaging devices. The method relates to the optical detection of particles or organisms of micrometric or sub-micrometric size by means of such a contact-imaging device, said particles or organisms being immersed in a drop (G) of liquid, the detection being carried out by means of a matrix of photosensitive cells or photosites. The method comprises a detection step or series of detection steps carried out during the evaporation of the liquid drop. It may also comprise a detection step carried out after the liquid drop has evaporated. Under certain conditions, it enables the reconstruction of a three-dimensional distribution of the particles or organisms in the initial drop before evaporation.