Transparent Particle Positioning via Offset Image Sensor

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Solution Overview

Problem

Existing optical analysis systems face challenges in precisely positioning transparent biological particles, such as microorganisms, due to their low absorption of visible light and small refractive index difference with the surrounding medium, leading to difficulties in maintaining the integrity and reliability of the analysis, especially when particles move or become detached during the analysis process.

Innovation Solution

The system employs an image sensor offset relative to the focusing plane, allowing for defocused image verification of particle position without moving the microscope objective or sample, enabling simultaneous or successive defocused and focused image acquisition to ensure precise positioning of the analysis beam on the particle, and uses calculation means to digitally reconstruct images and determine optimal offsets for precise particle positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual positioning under a microscope is used to position the focusing spot on the particle, then positioning precision is improved, but transparent particles cannot be detected due to low light absorption and small refractive index difference

Engineering Contradiction:
Improvepositioning precisionVSAvoidparticle detectability
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces a fluorescent labeling technique where antibodies conjugated to fluorescent dyes are used to label target antigens on transparent particles. The fluorescent label emits light at a different wavelength than the incident light, making transparent particles visible under the microscope. This resolves the contradiction by enabling detection of transparent particles through fluorescence emission rather than relying on their inherent optical properties.

Inventive Principle:
Principle #32Color changes

2Difficulty of detecting and measuring

If the particle is moved out of focus to obtain a clear image for positioning, then particle visibility is improved, but the particle may move or detach before measurement

Engineering Contradiction:
Improveparticle visibilityVSAvoidparticle position stability
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The patent implements a preliminary positioning step where the particle is first brought into focus and its position is recorded. Then the particle is moved out of focus for imaging to confirm positioning accuracy. Finally, the particle is returned to the original focused position for measurement. This preliminary action sequence ensures the particle position is verified before measurement while maintaining position stability throughout the process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses a feedback mechanism where the position of the particle is continuously monitored and adjusted. After moving the particle out of focus for imaging, the system checks whether the particle remains at the correct position and provides feedback to make necessary adjustments before returning to the measurement position. This feedback loop ensures particle position stability even when the particle is temporarily out of focus.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the analysis beam is focused on the particle, then measurement precision is improved, but the particle may move or detach during analysis

Engineering Contradiction:
Improveanalysis precisionVSAvoidparticle position stability during measurement
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent performs preliminary verification of particle positioning by imaging the particle out of focus before initiating the measurement. This preliminary action confirms the particle is correctly positioned and stable before the analysis beam is applied, reducing the risk of particle movement or detachment during the actual measurement process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements real-time feedback monitoring during the measurement process. The position control channel continuously monitors particle position while the analysis beam is focused on the particle, and provides feedback to maintain positioning accuracy. This feedback mechanism ensures that even if the particle begins to move during analysis, the system can detect and correct the position to maintain measurement reliability.

Inventive Principle:
Principle #23Feedback

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

This approach guarantees the reliability of particle analysis by detecting any displacement before focusing, preventing particle movement or detachment during the analysis and ensuring accurate positioning of the analysis beam, thus maintaining the integrity of the measurement.

Implementation Method 1

a second light source 110, in particular a laser, for illuminating the particle P

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 2

a second optical system 140, 150, comprising the microscope objective and a tube lens 150, for forming, in an image plane Π I, the image of the plane Π O receiving the analysis beam

Methodology Applied
Scientific EffectOptical imaging: Lens

Data Source

PatentEP3241014B1System for analysing a transparent sample with control of position, and associated method
Publication Date: 2023.08.30 BIOMERIEUX SA
  • EP3241014B1 patent drawingFigure 1
  • EP3241014B1 patent drawingFigure 2
  • EP3241014B1 patent drawingFigure 3

AI summary

The invention relates to a system (200) for analysing a transparent particle comprising: an analysis pathway, comprising a first light source (170) emitting an analysis light beam, and a first optical system (140) focusing the analysis light beam in a focusing plane ( Π 0 ); and a position control pathway comprising a second light source (110), an image sensor (160), and a second optical system (150, 140) at least partially merged with the first optical system. According to the invention the image sensor (160) is offset relative to the image ( Π/ ) of the focusing plane by the second optical system (150, 140). It makes it possible to control the correct positioning of the particle, even though it is transparent, and without disturbing the analysis pathway.