Polychromatic Illumination System for Biologic Substance Contrast

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Solution Overview

Problem

Existing illumination systems fail to achieve consistent visual contrast between substances with different reflectance properties when using multiple light sources, leading to metameric colors, which can result in varying color perception depending on the light source used.

Innovation Solution

An illumination system employing a first and second polychromatic light source with distinct spectra, where the first light source produces a consistent apparent color when scattered from a first substance and a different apparent color when scattered from a second substance, while the second light source produces distinct colors for both substances, combined with temporal modulation of light amounts to enhance color sensitivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If multiple light sources with different spectra are used to illuminate substances, then illumination intensity and color variety are improved, but visual contrast consistency deteriorates due to metamerism

Engineering Contradiction:
Improveillumination intensityVSAvoidvisual contrast consistency
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies parameter changes by selecting specific spectral parameters for multiple light sources. The system chooses light sources with spectra that satisfy metamerism conditions for background tissue while producing distinguishable colors for target tissue. This involves adjusting spectral composition, intensity ratios, and wavelength distributions to achieve consistent visual contrast across different illumination conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic action through temporal modulation of light source intensities. The controller alternates between different light sources or modulates their intensities in a periodic manner, allowing the observer's visual system to adapt and enhancing sensitivity to color differences. This periodic switching helps maintain consistent visual contrast by preventing adaptation to a single spectrum.

Inventive Principle:
Principle #19Periodic action

2Stability of the object's composition

If light sources are selected to achieve metamerism for one substance, then color consistency for that substance is improved, but color distinction for substances with different reflectance properties deteriorates

Engineering Contradiction:
Improveapparent color stabilityVSAvoidcolor distinction between substances
Core Design Contradiction:
Stability of the object's compositionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies local quality by tailoring the spectral characteristics of each light source to specific detection needs. Different wavelengths and spectral distributions are optimized for different tissue types: some spectra are designed to produce metamerism for background tissue while others are optimized to highlight target tissue. This localized spectral optimization allows simultaneous achievement of color stability for one substance and color distinction for another.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials concept by combining multiple light sources with complementary spectral properties. Each light source contributes specific spectral components that, when combined, create a composite illumination system capable of producing metamerism for background tissue while maintaining color distinction for target tissue. The controller integrates outputs from multiple sources to achieve the desired dual functionality.

Inventive Principle:
Principle #40Composite materials

3Measurement precision

If temporal modulation of light amounts is applied, then observer sensitivity to color differences is improved, but system complexity increases

Engineering Contradiction:
Improvecolor detection sensitivityVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamics by implementing temporal modulation of light source intensities. The controller dynamically adjusts the intensity of each light source over time, creating time-varying illumination patterns that enhance color contrast. This dynamic control allows the system to adapt to the observer's visual system response and maximize sensitivity to color differences between tissues.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the controller monitors the combined light output and adjusts individual light source intensities to maintain optimal color contrast. The system uses feedback from photodetectors or color sensors to detect actual color differences and modifies light source parameters accordingly, ensuring enhanced observer sensitivity while maintaining system stability.

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

The system ensures that the first substance appears constant in color regardless of the light source, while the second substance appears differently colored depending on the light source, improving visual contrast and observer sensitivity.

Implementation Method 1

a first apparent color results when the first light is scattered from the first biologic substance and a second apparent color results when the second light is scattered from the first biologic substance

Methodology Applied
Scientific EffectLight scattering: Scattering

Data Source

PatentEP2710349B1System and method for illuminating substances using color to achieve visual contrast
Publication Date: 2024.09.11 BAUSCH & LOMB INC
  • EP2710349B1 patent drawingFigure 1A
  • EP2710349B1 patent drawingFigure 1B~1C
  • EP2710349B1 patent drawingFigure 2

AI summary

An illumination system, comprising a first light output device to output polychromatic first light, a second light output device to output polychromatic second light, the first light output device and the second light output device selected so (i) a first apparent color results when the first light is scattered from the first biologic substance and a second apparent color results when the second light is scattered from the first biologic substance, the first apparent color and the second apparent color being the same and (ii) a third apparent color results when the first light is scattered from the second biologic substance and a fourth apparent color results when the second light is scattered from the second biologic substance, the third apparent color and the fourth apparent color being different, and means for temporally modulating amounts of the first light and amounts of the second light in a light output.