Optical Backscatter Measurement Device Using Magnified Detection Zones

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Solution Overview

Problem

Current optical instrumentation is unable to effectively characterize the epidermis, the surface layer of the skin, due to the limitations in minimizing the distance between optical fibers, which are typically a few hundred micrometers apart, making it difficult to accurately measure the optical properties of this shallow layer.

Innovation Solution

A device with an optical system that adjusts the backscatter distance between the illumination and detection zones to be less than 200 μm, allowing for precise characterization of the surface layer by using a magnification factor to control the distance between the elementary detection and illumination zones.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the distance between excitation and detection fibers is reduced to characterize the epidermis, then measurement precision for superficial layers is improved, but manufacturing precision constraints prevent significant reduction below a few hundred micrometers

Engineering Contradiction:
Improvemeasurement precisionVSAvoidmanufacturing precision
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

A microscope objective is introduced as an intermediary optical element between the fibers and the sample. The objective creates a magnification effect where the physical distance between fibers (constrained by manufacturing) is transformed into a smaller effective backscattering distance on the sample surface, enabling epidermis characterization while maintaining manufacturable fiber spacing

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The optical parameters of the system are changed by introducing a microscope objective with specific magnification properties. This transforms the relationship between physical fiber spacing and effective measurement depth, allowing the system to achieve shallow depth sensitivity (for epidermis) without requiring unmanufacturable small fiber spacings

Inventive Principle:
Principle #35Parameter changes

2Length of stationary object

If the distance between excitation and detection fibers is increased to characterize deeper dermis layers, then characterization depth is improved, but measurement precision for superficial epidermis layers deteriorates

Engineering Contradiction:
Improvecharacterization depthVSAvoidmeasurement precision
Core Design Contradiction:
Length of stationary objectVSMeasurement precision

Solution Approach 1:

The microscope objective acts as a mediator that decouples the relationship between fiber spacing and measurement depth. By controlling the magnification factor, the system can achieve both shallow and deep layer characterization capabilities with the same physical fiber configuration, optimizing for different dermal depths as needed

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If fiber diameter is reduced to achieve smaller backscattering distances, then measurement precision for superficial layers is improved, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Rather than reducing fiber diameters (which would increase manufacturing complexity and sensitivity to losses), the patent uses a microscope objective as an intermediary to achieve the desired small backscattering distance. This approach maintains standard fiber dimensions while achieving the optical effect of smaller spacing through magnification

Inventive Principle:
Principle #24Intermediary (Mediator)

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 the characterization of the optical properties of the surface layer, including the epidermis, with high spatial resolution, while maintaining comparable device dimensions to existing technologies, allowing for the determination of optical properties such as absorption and scattering coefficients.

Implementation Method 1

a light source capable of emitting a light beam towards a surface of said sample

Methodology Applied
Scientific EffectLight propagation: Light

Implementation Method 2

analyzing light backscattered by a diffusing object subjected to illumination

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

characterizing the optical properties or the nature of the materials that compose a sample... detection of a signal backscattered by a sample illuminated by a light beam

Methodology Applied
Scientific EffectLight scattering: Scattering

Implementation Method 4

characterizing the optical properties... their scattering and absorption properties

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 5

an optical system, having a magnification factor and an optical axis, said optical system being capable of connecting the distal end of each detection optical fiber to an elementary detection zone located on the surface of the sample

Methodology Applied
Scientific EffectOptical magnification: Lens

Data Source

PatentEP3054281B1Device for measuring an optical signal backscattered by a sample
Publication Date: 2020.07.29 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3054281B1 patent drawingFigure 1~2
  • EP3054281B1 patent drawingFigure 3A~3B
  • EP3054281B1 patent drawingFigure 4~5B

AI summary

The invention relates to a device for measuring an optical signal produced by a sample comprising: - a light source (10) capable of emitting a light beam (20) towards a surface of said sample (50), so as to form, on said surface, an elementary illumination zone (18), - at least one detection optical fiber (22), extending between a proximal end (24), capable of being coupled to a photodetector (40), and a distal end (26), capable of collecting an optical signal (52) backscattered by said sample when it is exposed to said light beam, - an optical system (30), having a magnification factor (G) and an optical axis (Z'), - said optical system (30) being capable of combining the distal end of each detection optical fiber (26) with an elementary detection zone (28, 28n) located on the surface of the sample, such that the distance (Dn), called the backscattering distance,between the elementary illumination zone (18) and each elementary detection zone (28, 28n), perpendicular to said optical axis, is a function of said magnification factor, the device being configured such that at least one elementary detection zone is separated from said illumination zone, the backscattering distance separating said elementary detection zone from said elementary illumination zone being less than 200 microns.