CN113176229A - Expiration detection method - Google Patents
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- CN113176229A CN113176229A CN202110465162.2A CN202110465162A CN113176229A CN 113176229 A CN113176229 A CN 113176229A CN 202110465162 A CN202110465162 A CN 202110465162A CN 113176229 A CN113176229 A CN 113176229A
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- 238000001514 detection method Methods 0.000 title claims abstract description 51
- 238000000034 method Methods 0.000 claims abstract description 13
- 238000001228 spectrum Methods 0.000 claims abstract description 12
- 241000282414 Homo sapiens Species 0.000 claims abstract description 9
- 238000010521 absorption reaction Methods 0.000 claims abstract description 6
- 230000009977 dual effect Effects 0.000 claims abstract description 4
- 238000004458 analytical method Methods 0.000 claims description 10
- 230000003321 amplification Effects 0.000 claims description 7
- 230000005540 biological transmission Effects 0.000 claims description 7
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 7
- 230000003287 optical effect Effects 0.000 claims description 5
- 238000006243 chemical reaction Methods 0.000 claims description 3
- 239000000284 extract Substances 0.000 claims description 3
- 238000000605 extraction Methods 0.000 claims description 2
- 230000008569 process Effects 0.000 abstract description 6
- 230000035945 sensitivity Effects 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 42
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 10
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 239000001257 hydrogen Substances 0.000 description 5
- 229910052739 hydrogen Inorganic materials 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 201000010099 disease Diseases 0.000 description 3
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 206010071061 Small intestinal bacterial overgrowth Diseases 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000004817 gas chromatography Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000007142 small intestinal bacterial overgrowth Effects 0.000 description 2
- 206010071200 Carbohydrate intolerance Diseases 0.000 description 1
- 208000018522 Gastrointestinal disease Diseases 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000000090 biomarker Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 238000002848 electrochemical method Methods 0.000 description 1
- 238000001285 laser absorption spectroscopy Methods 0.000 description 1
- 238000001307 laser spectroscopy Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004060 metabolic process Effects 0.000 description 1
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- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
- G01N21/39—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry using tunable lasers
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Abstract
The invention provides an expiration detection method, which comprises the following steps: s1: collecting and injecting the exhaled gas of the human body into a space division multiplexing air chamber; s2: scanning the frequency spectrum of the gas to be measured by using a dual laser; s3: receiving and transmitting the signal after the gas absorption by using a photoelectric detector; s4: and extracting the signal through a phase-locked amplifying unit. The invention can effectively improve the detection speed, the sensitivity and the gas selectivity; the operation process of the system is automatically completed by equipment, so that the burden of workers is reduced. After the detection is finished, a reference report is generated and transmitted to a computer and a printer for assisting the decision of the doctor on subsequent treatment, and the burden of the doctor is reduced. The method also has the advantages of high detection precision, short detection time, good anti-interference capability and the like. Has important clinical significance and wide application prospect.
Description
Technical Field
The invention relates to the technical field of laser spectroscopy, in particular to an expired air detection method.
Background
The gas exhaled by human beings reflects the metabolism and pathological conditions of the body, and some gases even can become biomarkers of certain diseases, so that bases can be provided for clinicians to quickly and non-invasively diagnose and identify the diseases. Commonly used detection technologies for human exhaled air include gas chromatography detection methods (such as an electronic nose), chemical sensor methods and the like, and the detection and analysis methods are complex in operation, high in instrument manufacturing cost and also need to be calibrated regularly; and the gas with single component can be detected and analyzed, and the gas with multiple components can not be analyzed and processed simultaneously, so that the response speed in the detection process is low, the concentration of the gas to be detected is difficult to be measured in real time, and the wide application of the gas to be detected in clinic is limited.
The gas chromatography technique and the electrochemical method detector that traditional methane hydrogen expiration detected and adopted must carry out artifical sample to gas, go to the laboratory again and analyze, so in whole measurement process, operator's operating skill has very big influence to detecting the precision to can only detect the analysis to the gas of single composition, can not carry out analysis processes to multiple gas simultaneously, the testing process response speed is slower, and the concentration of the gas that awaits measuring is difficult to obtain real-time measurement. The device is expensive, complex in operation and maintenance, long in analysis time, low in efficiency, short in service life, poor in anti-interference capability and extremely sensitive to environment, expiratory humidity and temperature changes.
Tunable semiconductor diode laser absorption spectroscopy (TDLAS) has now been developed as a commonly used trace gas detection technique as an emerging means in the field of gas detection. The TDLAS technique is based on the beer-lambert law and measures the amount of light absorbed by a gas to obtain an absorption intensity that is related to the concentration of the gas.
Disclosure of Invention
In order to overcome the existing technical problems and improve the detection speed, the sensitivity and the gas selectivity, the invention provides an expiration detection method.
In order to achieve the purpose, the invention adopts the following specific technical scheme:
the invention provides an expiration detection method, which comprises the following steps:
s1: collecting and injecting the exhaled gas of the human body into a space division multiplexing air chamber;
s2: scanning the frequency spectrum of the gas to be measured by using a dual laser;
s3: receiving and transmitting the signal after the gas absorption by using a photoelectric detector;
s4: and extracting the signal through a phase-locked amplifying unit.
Preferably, the twin laser as in step S2 includes: a first DFB laser and a second DFB laser; first DFB laser Scan H2A frequency spectrum; second DFB laser scanning CH4Frequency spectrum.
Preferably, the laser temperature control device further comprises a first laser driving temperature control unit for driving the first DFB laser, and a second laser driving temperature control unit for driving the second DFB laser; the first laser drives the temperature control unit and the second laser drives the temperature control unit to output driving signals; and the driven first DFB laser and the second DFB laser emit laser to be incident to the space division multiplexing gas chamber.
Preferably, the first laser driving temperature control unit and the second laser driving temperature control unit are respectively used for maintaining the normal operating temperature of the first DFB laser and the second DFB laser.
Preferably, the photodetector in step S3 is used to receive the optical signal completely absorbed by the gas to be measured in the space division multiplexing gas cell, and perform signal conversion.
Preferably, the high-frequency sine wave component in the driving signal is multiplied and transmitted to the phase-locked amplifying unit as a reference signal; the signal output by the photoelectric detector is transmitted to the phase-locked amplifying unit as a detection signal.
Preferably, the phase-locked amplifying unit of step S4 includes a high-precision CMOS operational amplifier, a high-precision demodulator, a phase-locked loop, and a D flip-flop; the phase-locked amplifying unit performs correlation operation on the detection signal and the reference signal, performs subsequent extraction of second harmonic, amplifies the harmonic signal, and extracts the amplitude.
Preferably, the method further comprises the following steps:
s5: and the data fitting unit performs data fitting analysis and transmits the data fitting analysis.
Preferably, the data fitting unit as step S5 is internally provided with a computer system, a storage system and a wireless transmission system; the computer system carries out typing on the collected information data; the storage system stores the collected information data; the wireless transmission system wirelessly uploads the information data to the upper computer.
The invention has the beneficial effects that:
the invention uses TDLAS technology to establish a methane hydrogen expiration detection system, which can effectively improve detection speed, sensitivity and gas selectivity; the defects of incapability of simultaneous detection, low precision, short service life, low speed and the like in the traditional method are overcome. The detection method can measure the gas concentrations of methane and hydrogen in real time and with high precision, and analyze the gas concentrations to help medical staff to judge the corresponding relationship between the exhaled gas of a human body and diseases, so that the diagnosis efficiency of a patient is greatly improved, and the cost is reduced.
The operation process of the system is automatically completed by equipment, so that the burden of workers is reduced. After the detection is finished, a reference report is generated and transmitted to a computer and a printer for assisting the decision of the doctor on subsequent treatment, and the burden of the doctor is reduced. The invention also has the advantages of high detection precision, short detection time, good anti-interference capability and the like. Has important clinical significance and wide application prospect.
Drawings
Fig. 1 is a block diagram of an expired air detection system according to an expired air detection method of the present invention.
Wherein the reference numerals are:
the system comprises a first laser driving temperature control unit 1, a second laser driving temperature control unit 2, a first DFB laser 3, a second DFB laser 4, a space division multiplexing air chamber 5, a photoelectric detector 6, a phase-locked amplification unit 7, a data fitting unit 8, an upper computer 9 and a printer 10.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.
A breath detection method provided by the present invention will be described in detail below.
The invention provides an expiration detection method, which comprises the following steps:
s1: collecting and injecting the exhaled gas of the human body into a space division multiplexing air chamber;
s2: scanning the frequency spectrum of the gas to be measured by using a dual laser;
s3: receiving and transmitting the signal after the gas absorption by using a photoelectric detector;
s4: the signal is extracted using a phase-locked amplification unit.
Through the gas detection of space division multiplexing by using a laser spectrum technology, a detection system for measuring the concentration of two component gases in human breath is constructed, and the gas concentrations of methane and hydrogen in the human breath are inverted according to the absorption degree of laser energy; gastrointestinal diseases such as carbohydrate intolerance, Small Intestinal Bacterial Overgrowth (SIBO) and the like are judged through an expiration test of methane and hydrogen.
Fig. 1 is a block diagram of an expired air detection system according to an expired air detection method of the present invention.
As shown in fig. 1, a distributed feedback laser (DFB laser) is used to perform a synchronized spectral scan of the gas under test that is admitted to the spatial multiplexing gas cell 5. The DFB laser has the characteristics that the line width can be very narrow, namely, the DFB laser can be made into laser which is very similar to monochromatic wave, so that the DFB laser is more accurate when scanning a single gas frequency spectrum; and the DFB laser can realize a wider wavelength tuning range and has good gas selectivity.
The twin laser in step S2 includes: a first DFB laser 3 and a second DFB laser 4; wherein the first DFB laser 3 scans H2A frequency spectrum; second DFB laser 4 scans CH4Frequency spectrum.
Further comprising a first laser drive temperature control unit 1 for driving a first DFB laser 3, and a second laser drive temperature control unit 2 for driving a second DFB laser 4; the first laser driving temperature control unit 1 and the second laser driving temperature control unit 2 output driving signals; the first and second DFB lasers 3 and 4 after driving emit laser light to enter the space division multiplexing gas cell 5.
The first laser driving temperature control unit 1 and the second laser driving temperature control unit 2 are used to maintain the normal operating temperatures of the first DFB laser 3 and the second DFB laser 4, respectively.
In one embodiment of the present invention, the first laser driving temperature control unit 1 and the second laser driving temperature control unit 2 are each composed of a main control chip having a microcontroller, an operational amplifier chip having an independent enable terminal, and a power amplifier having an H-bridge structure.
In one embodiment of the invention, the first DFB laser 3 and the second DFB laser 4 are both in optical transmission relationship with the space division multiplexing gas cell 5 through optical fibers. The laser light generated by the first and second DFB lasers 3 and 4 is simultaneously incident on the spatial multiplexing gas cell 5 via the optical fiber. The space division multiplexing gas chamber 5 is provided with a control rod, and the optical path of the laser are controlled by the control rod, so that the laser can be fully absorbed by the gas.
The output end of the space division multiplexing air chamber 5 is connected with the input end of the photoelectric detector 6; the photoelectric detector 6 is used for receiving the optical signal completely absorbed by the gas to be detected in the space division multiplexing gas chamber 5 and performing signal conversion.
The high-frequency sine wave component in the driving signals output by the first laser driving temperature control unit 1 and the second laser driving temperature control unit 2 is doubled and transmitted to the phase-locking amplification unit 7 as a reference signal; the signal output by the photodetector 6 is transmitted to the phase-locked amplification unit 7 as a detection signal.
The phase-locked amplifying unit 7 comprises a high-precision CMOS operational amplifier, a high-precision demodulator, a phase-locked loop and a D trigger; the phase-locked amplifying unit 7 receives the signal output by the photoelectric detector 6 and extracts the amplitude of the signal to be measured.
In an embodiment of the present invention, from the frequency selection characteristic of the TDLAS technology, the second harmonic is subsequently extracted through the phase-locked amplification unit 7 to obtain the detection concentration of the corresponding frequency point, so as to improve the detection accuracy of the system, reduce the background noise, and further improve the reliability of the system.
When the phase-locked amplifying unit 7 detects, the detection signal and the reference signal are subjected to correlation operation, the harmonic signal is amplified, and the amplitude of the harmonic signal is extracted, so that the noise suppression capability of the instrument can be improved by several orders of magnitude.
The breath detection method of the present invention further comprises the steps of:
s5: the data fitting unit 8 performs data fitting analysis and transmits.
A computer system, a storage system and a wireless transmission system are arranged in the data fitting unit 8; the computer system carries out typing on the collected information data; the storage system stores the collected information data; the wireless transmission system wirelessly uploads the information data to the upper computer 9.
In an embodiment of the invention, the detection data is uploaded to the upper computer 9 and the parallel network printer 10 in a real-time wireless manner, the reference report is printed, and medical staff can perform further processing operation according to the analysis result of the reference report, so that convenience is provided for the medical staff.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.
Claims (9)
1. A method of breath detection comprising the steps of:
s1: collecting and injecting the exhaled gas of the human body into a space division multiplexing air chamber (5);
s2: scanning the frequency spectrum of the gas to be measured by using a dual laser;
s3: receiving and transmitting the signal after the gas absorption by using a photoelectric detector (6);
s4: the signal is extracted by a phase-locked amplification unit (7).
2. The breath detection method of claim 1, wherein the twin laser of step S2 comprises: a first DFB laser (3) and a second DFB laser (4); the first DFB laser (3) scans H2A frequency spectrum; the second DFB laser (4) scans CH4Frequency spectrum.
3. The breath detection method according to claim 2, further comprising a first laser driving temperature control unit (1) for driving the first DFB laser (3), and a second laser driving temperature control unit (2) for driving the second DFB laser (4); the first laser driving temperature control unit (1) and the second laser driving temperature control unit (2) output driving signals; the first DFB laser (3) and the second DFB laser (4) after being driven emit laser light to be incident to the space division multiplexing gas chamber (5).
4. The breath detection method according to claim 3, wherein the first laser drive temperature control unit (1) and the second laser drive temperature control unit (2) are used to maintain a normal operating temperature of the first DFB laser (3) and the second DFB laser (4), respectively.
5. The breath detection method according to claim 3, wherein the photodetector (6) according to step S3 is configured to receive the optical signal completely absorbed by the gas to be detected in the spatial multiplexing gas cell (5) and perform signal conversion.
6. The breath detection method according to claim 5, wherein the high frequency sine wave component in the driving signal is doubled and transmitted to the phase-locked amplifying unit (7) as a reference signal; and the signal output by the photoelectric detector (6) is transmitted to a phase-locked amplifying unit (7) as a detection signal.
7. The breath detection method according to claim 6, wherein the phase-locked amplification unit (7) according to step S4 comprises a high-precision CMOS operational amplifier, a high-precision demodulator, a phase-locked loop, and a D flip-flop; the phase-locked amplifying unit (7) performs correlation operation on the detection signal and the reference signal, performs subsequent extraction of second harmonic, amplifies the harmonic signal, and extracts the signal amplitude.
8. The breath detection method of claim 1, further comprising the steps of:
s5: and the data fitting unit (8) performs data fitting analysis and transmits the data fitting analysis.
9. The breath detection method according to claim 8, wherein the data fitting unit (8) of step S5 is internally provided with a computer system, a storage system and a wireless transmission system; the computer system carries out typing on the collected information data; the storage system stores the collected information data; the wireless transmission system wirelessly uploads the information data to an upper computer (9).
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| CN202110465162.2A CN113176229A (en) | 2021-04-26 | 2021-04-26 | Expiration detection method |
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| CN202110465162.2A CN113176229A (en) | 2021-04-26 | 2021-04-26 | Expiration detection method |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114235742A (en) * | 2021-12-17 | 2022-03-25 | 中国石油大学(华东) | Composite spectrum detection system and method based on respiratory gas major markers |
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2021
- 2021-04-26 CN CN202110465162.2A patent/CN113176229A/en active Pending
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| US20030134427A1 (en) * | 2002-01-11 | 2003-07-17 | Chad Roller | Method and apparatus for determining gas concentration |
| CN104198433A (en) * | 2014-09-14 | 2014-12-10 | 中国科学院合肥物质科学研究院 | Device and method for detecting concentration of human respiration marking gas on line by laser absorption spectroscopy technology |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114235742A (en) * | 2021-12-17 | 2022-03-25 | 中国石油大学(华东) | Composite spectrum detection system and method based on respiratory gas major markers |
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