Carbon Dioxide Detection Apparatus with Dual-Path Optical Filtering
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Solution Overview
Problem
Existing carbon dioxide detection technologies, particularly those using laser-based optical sensors, face challenges such as high costs, bulkiness, susceptibility to optical interferences, and the need for frequent calibration and maintenance.
Innovation Solution
A compact carbon dioxide detection apparatus utilizing a radiation source, a gas measuring chamber, and a radiation filter with two detection paths to separate radiation over the carbon dioxide absorption band from other wavelengths, allowing for enhanced signal intensity and reduced background noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laser-based optical sensors are used for carbon dioxide detection, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The detection system is segmented into distinct functional components: a broadband radiation source, a radiation filter that separates wavelengths, and separate detection paths for reference and measurement signals. This segmentation allows each component to be optimized independently and simplifies the overall system compared to monomodal laser systems.
Solution Approach 2:
The broadband radiation source serves multiple functions by providing radiation across various wavelengths simultaneously - both the carbon dioxide absorption wavelength and reference wavelengths are obtained from the same source, eliminating the need for multiple specialized laser sources and reducing system complexity.
2Measurement precision
If laser-based optical sensors are used for carbon dioxide detection, then measurement precision is improved, but device size increases
Solution Approach 1:
Multiple detection paths (reference and measurement) are merged into a single integrated sensor unit with shared optical components. The radiation filter and detection elements are combined in one housing, creating a compact system that eliminates the need for external laser modules and fiber optic cables.
3Measurement precision
If external laser light sources are used, then measurement precision is improved, but reliability decreases due to optical interferences
Solution Approach 1:
The harmful optical interferences are extracted and isolated by using a broadband source with a radiation filter that selectively transmits only the desired wavelengths to the detection paths. This separates the useful measurement signal from the interfering background radiation, improving signal stability.
Solution Approach 2:
The radiation filter acts as an intermediary component that processes the broadband radiation from the source, separating the carbon dioxide absorption wavelength from other wavelengths. This intermediary function eliminates optical interferences while preserving the measurement precision.
4Measurement precision
If laser light sources are used, then measurement precision is improved, but ease of operation worsens due to frequent calibration requirements
Solution Approach 1:
The system performs self-calibration using the reference detection path that continuously monitors the radiation source stability. The reference path automatically compensates for drift and calibration shifts, eliminating the need for manual recalibration and improving ease of operation.
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 solution provides a cost-effective, compact, and reliable carbon dioxide detection system with improved signal-to-noise ratio and reduced assembly complexities, enabling efficient and accurate monitoring with minimal maintenance.
Implementation Method 1
The radiation entering the gas measuring chamber has wavelengths that extend over an absorption band of carbon dioxide and has wavelengths that extend over a region other than the absorption band of carbon dioxide
Implementation Method 2
The radiation filter is positioned relative to the gas measuring chamber such that an interaction radiation path is defined between the radiation source through the gas measuring chamber to the radiation filter
Data Source
AI summary
The present invention relates to an apparatus (10) apparatus for the detection of carbon dioxide. It is described to place (210) a part of a housing in contact with a skin area of a patient. the part of the housing and a gas measuring chamber within the housing are configured such that gases diffusing through the skin area of the patient enter the gas measuring chamber. radiation is emitted (220) from a radiation source within the housing, wherein at least some of the radiation emitted by the radiation source enters the gas measuring chamber. The radiation entering the gas measuring chamber has wavelengths that extend over an absorption band of carbon dioxide and has wavelengths that extend over a region other than the absorption band of carbon dioxide. A radiation filter is positioned (230) relative to the gas measuring chamber such that an interaction radiation path is defined between the radiation source through the gas measuring chamber to the radiation filter. A first radiation detector is positioned (240) relative to the radiation filter such that a first detection radiation path is defined that is in addition to the interaction radiation path, and a second radiation detector is positioned relative to the radiation filter such that a second detection radiation path is defined that is in addition to the interaction radiation path. The radiation filter is configured such that radiation in the first detection radiation path has a wavelength that extends over the absorption band of carbon dioxide and with an intensity of radiation that extends over the region other than the absorption band being significantly less than that in the interaction radiation path. The radiation filter is also configured such that radiation in the second detection radiation path has a wavelength that extends over the region other than the absorption band of carbon dioxide and with an intensity of radiation that extends over the absorption band being significantly less than that in the interaction radiation path. a partial pressure of carbon dioxide is determined (250) in the skin of the patient using a signal from the first radiation detector and a signal from the second radiation detector.