Complementary Safety Interlocks for Portable LIBS Laser Firing

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Solution Overview

Problem

Portable LIBS devices face safety challenges due to the limitations of single safety mechanisms, which can incorrectly prevent operation when it is safe to operate, especially with varying sample types and conditions, leading to potential harm from accidental laser exposure.

Innovation Solution

Implementing complementary safety mechanisms, such as gas pressure, light, inductive sensing, mechanical proximity, and spectral feedback interlocks, which work together to ensure safe operation by allowing the device to function only when multiple safety conditions are met, thereby preventing unsafe laser emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a single safety mechanism is used to prevent accidental laser exposure, then safety protection is provided, but the device may incorrectly prevent operation when it is safe to operate, reducing reliability

Engineering Contradiction:
Improvelaser exposure safetyVSAvoidoperational reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The safety system is divided into multiple independent safety mechanisms (chamber pressure interlock, chamber light interlock, inductive interlock, spectral detection interlock) that each monitor different safety parameters. This segmentation allows each mechanism to focus on specific safety aspects while the combination provides comprehensive protection without false positives.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple safety mechanisms are merged into a single integrated safety system where all interlocks must be satisfied simultaneously for laser operation to be permitted. This combining approach ensures that safety protection is multi-layered and that the laser can only fire when all safety conditions are met, preventing both accidental exposure and false safety activations.

Inventive Principle:
Principle #5Merging (Combining)

2Object-affected harmful factors

If safety mechanisms are made more sensitive to detect unsafe conditions, then safety protection is improved, but false activations increase causing operational restrictions

Engineering Contradiction:
Improvesafety protectionVSAvoidoperational ease
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

Each safety mechanism provides feedback on its specific parameter (pressure, light intensity, inductive sensing, spectral detection) to the control system. The control system uses this feedback to make informed decisions about laser operation, allowing the device to operate easily when conditions are safe while automatically restricting operation only when actual unsafe conditions are detected.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system monitors multiple physical parameters (pressure, light intensity, electromagnetic induction, spectral distribution) and uses threshold-based decision logic to determine safety status. By changing the parameter thresholds and monitoring multiple parameters simultaneously, the system achieves high sensitivity for safety detection while minimizing false activations through multi-parameter verification.

Inventive Principle:
Principle #35Parameter changes

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 combination of safety mechanisms enhances the reliability of portable LIBS devices by preventing unsafe laser firing while allowing operation in safe circumstances, even when individual mechanisms are activated, thus improving user and bystander safety during field use.

Implementation Method 1

focusing a short-pulse laser beam onto the surface of a sample, with sufficient power density such that a small quantity of the sample is ablated, or removed by both thermal and non-thermal transformations

Methodology Applied
Scientific EffectLaser ablation: Ablation

Implementation Method 2

optical emissions from the resulting plasma plume are collected with the appropriate light collection optics, and the spectral distribution (i.e., intensity versus wavelength) of the optical emissions is detected by a spectrometer

Methodology Applied
Scientific EffectOptical emission spectroscopy: Absorption Spectroscopy

Implementation Method 3

electrons of atoms and ions at the excited electronic states of the plasma return to their lower energy or ground states, causing the emission of radiation at discreet wavelengths

Methodology Applied
Scientific EffectElectron transition emission: Luminescence

Data Source

PatentEP3655737B1Complementary safety systems for laser induced breakdown spectroscopy
Publication Date: 2025.03.26 THERMO SCIENTIFIC PORTABLE ANALYTICAL INSTRUMENTS INC
  • EP3655737B1 patent drawingFigure 1
  • EP3655737B1 patent drawingFigure 2
  • EP3655737B1 patent drawingFigure 3

AI summary

In the operation of analytical devices, and particularly laser induced breakdown spectroscopy (LIBS) devices, a number of advantages may be obtained by the use of complementary safety mechanisms, such as those that govern the operation or firing of a laser. Such complementary safety mechanisms, compared to the individual safety mechanisms acting alone, prevent operation of the laser under a greater number of unsafe circumstances (even if one or more detected conditions are safe, based on not activating the associated safety mechanism) and permits operation under a greater number of safe circumstances (even if one or more detected conditions are unsafe, based on activating the associated safety mechanism).