Device and method for detecting concentration of human respiration marking gas on line by laser absorption spectroscopy technology

Abstract

The invention discloses a device and a method for detecting the concentration of human respiration marking gas on line by a laser absorption spectroscopy technology. The device is characterized in that a laser temperature control plate and a laser current control plate are used for controlling a DFB (distributed feedback) laser device; a signal generator is used for generating sawtooth waves and sine waves; laser with the specific absorption wavelength is output by the laser device and collimated by an optical fiber collimator, enters a light-sound gas pool, and is reflected for multiple times by two high-reflectivity concave mirrors to interact with gas to be detected; a light-sound signal detected by a microphone is transmitted to a front amplifier, enters a phase-lock amplifier and is finally acquired and processed by a computer and a data acquisition card. The method is characterized in that a tester blows air into a vapor drying bottle through a respiration air nozzle to remove vapor and the air enters the light-sound gas pool, and an air pressure control pump, a temperature detection meter and a pressure detection meter are used for controlling the pressure in the pool and acquiring the temperature and the pressure for inverse concentration calibration. The device is unique in design and novel in structure; the in-situ online detection is performed, the complexity of other detection technologies is avoided, and the detection precision is improved.

Description

technical field [0001] The present invention relates to a device and method for on-line detecting the concentration of human respiration-marking gas by laser absorption spectroscopy, more specifically, a device and method for detecting the concentration of human respiration-marking gas based on photoacoustic spectroscopy and wavelength-modulated absorption spectroscopy. Device and method for online detection. Background technique [0002] With the development of modern medical technology and the integration of multiple disciplines, the early diagnosis technology of major diseases, which is the foreword of medical research, is constantly breaking through and innovating. In particular, respiratory biomarker technology for the diagnosis of major diseases has developed rapidly. Medical research has shown that nitrogen (N 2 ), oxygen (O 2 ), carbon dioxide (CO 2 ), water vapor (H 2 O) and inert gases also contain many ppm (parts-per-million, 10 -6 ) or even ppb (parts-per-b...

AI Technical Summary

Problems solved by technology

The traditional analysis method of gas chromatography-mass spectrometry for breath detection can make the measurement accuracy of breath gas markers reach ppb or even ppt level, but this method takes a long time, the instrument is bulky, and the cost is high, so it is only suitable for laboratories at present Research, unable to enter the substantive clinical stage, it is difficult to realize the portability of the instrument and enter the community and family

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