Fluorescence Analyzer Normalization via Spectral Characterization

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Solution Overview

Problem

Current methods for normalizing fluorescence analyzer responses in fluorometry introduce variability due to wavelength characteristics, requiring costly optimization of filters and sources, and are inefficient as they necessitate running multiple samples on each analyzer to determine normalization factors.

Innovation Solution

A method involving the use of a spectrometer to measure excitation and emission spectra of the fluorescence analyzer, determining wavelength characteristic functions to calculate a normalization factor that corrects analyzer responses, reducing analyzer-to-analyzer variation by accounting for wavelength-based biases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple samples are run on each analyzer to determine normalization factors, then measurement precision is improved, but productivity deteriorates due to time-consuming multiple runs

Engineering Contradiction:
Improvemeasurement precisionVSAvoidproductivity
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent measures and stores wavelength characteristic functions (excitation and emission spectra) for each analyzer in advance during manufacturing or calibration. These pre-measured spectral characteristics are then used to calculate normalization factors without requiring multiple sample runs during actual measurement operations, thereby improving productivity while maintaining precision

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If filters and sources are optimized to reduce wavelength variation, then measurement precision is improved, but device complexity and manufacturing cost increase

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

Solution Approach 1:

The patent replaces the mechanical/optical optimization approach (optimizing filters and light sources to reduce wavelength variation) with a computational approach. By measuring the actual wavelength characteristics of each analyzer and using these measured values to calculate normalization factors through mathematical functions, the system compensates for wavelength variations without requiring complex optical optimizations, thereby reducing device complexity and manufacturing costs

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

3Ease of operation

If a single normalization factor is determined for one slide lot and applied to all slide lots, then ease of operation is improved, but measurement precision deteriorates due to lack of accuracy for specific slide lots

Engineering Contradiction:
Improveease of operationVSAvoidmeasurement precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent calculates normalization factors specifically for each slide lot based on the measured wavelength characteristics of the analyzers. Instead of using a single universal normalization factor, the system determines slide lot-specific normalization factors by measuring the excitation and emission spectra for each analyzer and calculating the appropriate normalization factor for that specific slide lot, thereby maintaining ease of operation while improving measurement precision through localized customization

Inventive Principle:
Principle #3Local quality

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 enhances the precision and uniformity of electrolyte concentration measurements across all analyzers by specifically addressing wavelength-based variability, reducing the need for costly filter optimization and simplifying the normalization process.

Implementation Method 1

measuring, using a spectrometer configured to receive an output illumination signal from the fluorescence analyzer, an excitation spectrum of the output illumination signal output from the fluorescence analyzer

Methodology Applied
Scientific EffectSpectroscopy: Absorption Spectroscopy

Implementation Method 2

Filter fluorometry refers generally to the process of illuminating a sample and quantitating the resulting, detected fluorescence signal

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 3

measuring an emission sensitivity spectrum obtained by the fluorescence analyzer in response to input of an input illumination signal into the fluorescence analyzer using a monochromator to obtain a data set of relative irradiance sensitivity as a function of wavelength

Methodology Applied
Scientific EffectMonochromator dispersion: Diffraction Grating

Data Source

PatentEP2724130B1Method of normalizing a fluorescence analyzer
Publication Date: 2023.12.27 IDEXX LABORATORIES INC
  • EP2724130B1 patent drawingFigure 1
  • EP2724130B1 patent drawingFigure 2
  • EP2724130B1 patent drawingFigure 3

AI summary

A method of normalizing an analyzer response value of a fluorescence analyzer is provided. The method includes measuring an excitation spectrum of the analyzer and measuring an emission sensitivity spectrum of the analyzer. Next, a normalization factor based at least in part upon the excitation spectrum of the analyzer and the emission sensitivity spectrum of the analyzer is determined. The sample is then analyzed to obtain an uncorrected analyzer response value. A normalized analyzer response value is calculated based at least in part upon the uncorrected analyzer response value and the normalization factor.