Tunable Interference Filter Gas Analyzer for Compact Multi-Gas Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current clinical mainstream gas analyzers are unable to accurately measure multiple gases due to widely spaced wavelength regions of absorption, contamination issues, and size constraints, limiting their application to small patients and requiring complex mechanical components like rotating filter wheels or multiple beam splitters.
Innovation Solution
A compact gas analyzer design utilizing two tunable narrowband interference filters with dielectric mirrors and an air space, allowing a single detector to measure multiple gases by tuning the filters to different transmission bands, covering wavelength regions for carbon dioxide, nitrous oxide, and anesthetic agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If rotating filter wheels or multiple beam splitters are used to measure multiple gases, then measurement capability for multiple gases is improved, but device complexity and size increase
Solution Approach 1:
The patent applies dynamic tuning of fixed interference filters using piezoelectric actuators to change the air space between dielectric mirrors, enabling a single optical path to measure multiple gases with widely spaced wavelength regions without mechanical moving parts like filter wheels
Solution Approach 2:
The patent replaces mechanical filter wheel systems with electronically controlled piezoelectric actuators that adjust the optical path length, substituting mechanical movement with electro-mechanical actuation to achieve wavelength tuning without rotating components
2Volume of moving object
If the gas analyzer is made compact for small patients, then applicability to neonatal and pediatric patients is improved, but measurement accuracy for multiple gases deteriorates
Solution Approach 1:
The compact design achieves multi-gas measurement by dynamically tuning the air space in fixed interference filters using piezoelectric actuators, allowing a single compact optical path to access widely spaced wavelength regions for different gases without requiring large mechanical filter wheels
Solution Approach 2:
The patent merges multiple measurement capabilities into a single optical path by using dynamically tunable fixed interference filters, combining the functions of what would traditionally require separate optical paths, filter wheels, and multiple detectors into one integrated compact system
3Device complexity
If fixed bandpass filters are used, then device simplicity is improved, but ability to measure gases with widely spaced wavelength regions deteriorates
Solution Approach 1:
The patent maintains the simplicity of fixed interference filter structures while adding dynamic tuning capability through piezoelectric actuators that adjust the air space between dielectric mirrors, enabling coverage of widely spaced wavelength regions for different gases without complex mechanical filter wheels
Solution Approach 2:
The patent changes the optical path length parameter in fixed interference filters using piezoelectric actuation to shift the transmission bands, allowing the same physical filter structure to measure different gases with widely spaced absorption wavelengths by adjusting the air space dimension
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
Enables accurate, compact, and lightweight measurement of multiple respiratory gases with reduced component count and no moving parts, suitable for neonatal and pediatric patients, while maintaining accuracy and reliability.
Implementation Method 1
the measurement is based on the absorption of infrared (IR) radiation in the gas sample
Implementation Method 2
an emitter for being able to emit infrared radiation through the gas
Implementation Method 3
a filter assembly for allowing a transmission of predetermined wavelengths emitted by the emitter, The filter assembly comprises at least two tunable narrowband interference filters
Implementation Method 4
each of the filters comprising two dielectric mirrors and an air space between the two dielectric mirrors
Data Source
Figure 1~4
Figure 5~7
AI summary
A gas analyzer for measuring at least two components of a gas is disclosed herein. The gas analyzer includes an emitter (17) for being able to emit infrared radiation through the gas and a filter assembly (32) for allowing a transmission of predetermined wavelengths emitted by the emitter. The gas analyzer also includes a detector (31) for receiving wavelengths emitted by the emitter and penetrated through the filter assembly. The filter assembly comprises at least two tunable narrowband interference filters (33, 43) in series, each of the filters comprising two dielectric mirrors (35, 36 and 45, 46) and an air space (34, 44) between the two dielectric mirrors to tune one of the filters to different transmission band than another of the filters. (Fig. 5)