Polychromatic LED Oximeter for Rapid Hemoglobin Analysis

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Solution Overview

Problem

Current oximeters are time-consuming in acquiring spectra due to the use of diffraction gratings and lack stability and long service life, making them less user-friendly and less accurate for quick, multi-component analysis of hemoglobin derivatives and other analytes in medical samples.

Innovation Solution

A compact oximeter using a polychromatic LED as the measuring light source, emitting radiation in specific spectral ranges for hemoglobin derivatives and other analytes, ensuring significant absorption and differential absorption values, with a homogeneous spectrum over the exit surface for reduced tolerance sensitivity and improved alignment robustness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If diffraction gratings are used to split measuring light into spectral components, then spectral analysis can be performed, but the spectrum acquisition becomes time-consuming

Engineering Contradiction:
Improvespectral analysis capabilityVSAvoidspectrum acquisition time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts and removes the diffraction grating component from the optical system. Instead of using a diffraction grating to split light into spectral components, the invention uses a polychromatic LED that directly emits broadband radiation covering the required spectral range (400-700 nm), eliminating the time-consuming mechanical scanning process while maintaining spectral analysis capability through direct detection by the photodetector array

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical diffraction grating system with an optical source (polychromatic LED) that inherently provides the desired spectral output. This substitution eliminates moving parts and mechanical scanning, enabling simultaneous acquisition of spectral information across the entire measurement range, thus dramatically reducing measurement time while preserving the ability to perform spectral analysis

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

2Illumination intensity

If conventional light sources like halogen lamps are used, then broad spectral range is available, but stability and service life are reduced

Engineering Contradiction:
Improvespectral range coverageVSAvoidsource stability and service life
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the fundamental parameters of the light source by transitioning from a thermal radiation source (halogen lamp) to a solid-state LED source. The polychromatic LED operates at lower temperatures, consumes less power, and provides inherent stability through its solid-state construction. The spectral output (400-700 nm) is achieved through the LED's emission characteristics rather than thermal radiation, resulting in improved service life, stability, and reduced maintenance requirements while maintaining broad spectral coverage

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple monochromatic wavelengths are radiated sequentially, then specific wavelength ranges can be filtered, but the measurement process becomes time-consuming

Engineering Contradiction:
Improvewavelength-specific detectionVSAvoidmeasurement speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements continuous simultaneous measurement across the entire spectral range by using a polychromatic LED that emits broadband radiation (400-700 nm) all at once. The photodetector array detects all wavelengths simultaneously without sequential scanning, enabling continuous acquisition of spectral information for multiple analytes (hemoglobin derivatives and bilirubin) in a single measurement step, thereby dramatically improving measurement speed and productivity

Inventive Principle:
Principle #20Continuity of useful action

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 solution allows for quick spectrum recording, increased stability, longer service life, and high accuracy in determining hemoglobin derivatives and additional analytes like bilirubin, with reduced maintenance and improved user-friendliness.

Implementation Method 1

a measuring light source (1) which is a polychromatic LED and which, for determining the hemoglobin derivatives, emits measuring radiation at least in a spectral range B, in which the hemoglobin derivatives have a significant absorption

Methodology Applied
Scientific EffectLight emission from LED: Light Emitting Diode

Implementation Method 2

for detecting at least one further analyte, measuring radiation at least in a further spectral range A is emitted, in which the at least one further analyte has a significant absorption

Methodology Applied
Scientific EffectAbsorption of light: Absorption (EM radiation)

Data Source

PatentEP1987765B1Oximeter
Publication Date: 2012.08.15 ROCHE DIAGNOSTICS GMBH
  • EP1987765B1 patent drawingFigure 1~2
  • EP1987765B1 patent drawingFigure 3~4
  • EP1987765B1 patent drawingFigure 5~6

AI summary

The oximeter has a sample chamber (5), a detection device, which receives a spectrum of the measuring radiation after its interaction with the sample and an evaluation device downstream to the detection device. The measuring light source (1) is a polychromate light emitting diode, which determines measuring radiation in a spectral area for determining the hemoglobin derivative and determines measuring radiation in another spectral area for collecting another analyte.