Dual-Wavelength Laser Interface Detection in Automated Lab Systems

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Solution Overview

Problem

Existing laboratory automation systems face challenges in accurately detecting the vertical position of interfaces between components in sample containers, especially when labels are attached, leading to reduced signal quality and increased noise due to multiple label layers.

Innovation Solution

A laboratory automation system utilizing two vertically spaced sensing units with laser diodes emitting different wavelengths, collimating optics, and a driving unit for relative motion, which allows for precise interface detection by matching and calculating the vertical position of interfaces, and optionally rotating the sample container to improve signal-to-noise ratio.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If labels are attached to the sample container for identification, then sample tracking and identification are improved, but signal quality deteriorates and noise increases due to multiple label layers blocking light transmission

Engineering Contradiction:
Improvesample identification informationVSAvoidinterface detection accuracy
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The invention divides the light detection function into multiple wavelength channels (first wavelength and second wavelength). Each wavelength is selectively transmitted or blocked by different components, allowing the system to segment the detection process to penetrate through label layers while detecting component interfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the optical parameter (wavelength) of the light used for detection. By using multiple wavelengths with different transmission characteristics, the system can optimize light penetration through labels while maintaining sensitivity to component interfaces, thus improving measurement precision despite the presence of labels.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a single optical channel with single wavelength is used, then device complexity is reduced, but measurement precision deteriorates due to inability to differentiate between label layers and component interfaces

Engineering Contradiction:
Improveoptical channel configurationVSAvoidinterface position detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The invention segments the optical detection into multiple wavelength channels, each with distinct transmission properties. This allows differentiation between label layers and component interfaces based on their differential light absorption and transmission characteristics across wavelengths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention utilizes multiple optical wavelengths as varying parameters to enhance detection capability. The first wavelength is substantially transmitted by both the sample container and first component, while the second wavelength is substantially transmitted by the sample container but blocked by the first component, enabling precise interface detection.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If multiple sensing units are used to improve detection accuracy, then measurement precision is improved, but device complexity increases due to additional optical components and alignment requirements

Engineering Contradiction:
Improveinterface detection accuracyVSAvoidsensing unit configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention designs the sensing units to perform multiple functions: detecting both label layer positions and component interface positions using different wavelengths. This multi-functionality reduces the need for separate detection systems, thereby managing device complexity while improving measurement precision.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

Enhances the accuracy and efficiency of interface detection in sample containers with multiple labels by optimizing wavelength-specific collimation and relative motion, reducing processing time and improving signal quality.

Implementation Method 1

a first laser diode that emits light having a first wavelength, the first wavelength being substantially transmitted by the sample container and a first component

Methodology Applied
Scientific EffectLight transmission: Light

Implementation Method 2

a second laser diode that emits light having a second wavelength, the second wavelength being substantially transmitted by a sample container but blocked or absorbed by the first component

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

a first collimating optics adapted to collimate the light of the first wavelength that is generated by the first laser diode, such that the light is emitted in form of a beam having a defined diameter and direction in space

Methodology Applied
Scientific EffectCollimation: Lens

Data Source

PatentEP2770317B1Apparatus for determining a vertical position of at least one interface between a first component and at least one second component and laboratory automation system
Publication Date: 2017.09.20 ROCHE DIAGNOSTICS GMBH
  • EP2770317B1 patent drawingFigure 1~2
  • EP2770317B1 patent drawingFigure 3~4
  • EP2770317B1 patent drawingFigure 5

AI summary

Apparatus for determining a vertical position of at least one interface (IF) between a first component (1) and at least one second component (10), the components (1, 10) being comprised as different layers in a sample container (3), the apparatus comprising: a first sensing unit (4) comprising: a first laser diode (4a) emitting light having a first wavelength, which is substantially transmitted by the sample container (3) and the first component (1), a first collimating optics (4b) adapted to collimate the light having the first wavelength, a first light detector (4c) generating a first sensing signal (S1) in response to an intensity of light having the first wavelength being applied to the first light detector (4c), a second sensing unit (5) vertically spaced by a given vertical distance (D) from the first sensing unit (4) and comprising: a second laser diode (5a) emitting light having a second wavelength, which is substantially transmitted by the sample container (3) but blocked by the first component (1), a second collimating optics (5b) adapted to collimate the light having the second wavelength, a second light detector (5c) generating a second sensing signal in response to an intensity of light having the second wavelength being applied to the second light detector (5c), a driving unit (6) adapted to move the first sensing unit (4) and the second sensing unit (5) relative to the sample container (3), a position sensing unit (7a, 7b), adapted to output a position sensing signal (z) indicative of a vertical position of the sample container (3), and a vertical position determining unit (8), adapted to match the first sensing signal and the second sensing signal such that first sensing signal and the second sensing signal correspond to identical vertical positions, and calculate the vertical position of the at least one interface (IF) in response to the matched sensing signals and the position sensing signal (z).