A micro optical gas sensor

Abstract

The present invention discloses a micro optical gas sensor, comprising a housing, a micro gas chamber, an oxygen detection unit, a carbon dioxide detection unit and a control processing unit. The housing is provided with an air inlet unit and an air outlet unit; the micro gas chamber is arranged in the housing and is connected to the air inlet unit and the air outlet unit; the oxygen detection unit transmits a first light beam to the micro gas chamber and generates a first detection signal, which is received by the first detector; the carbon dioxide detection unit transmits a second light beam to the micro gas chamber and generates a second detection signal, which is received by the second detector; the present invention miniaturizes and integrates an oxygen detection unit based on the TDLAS principle and a carbon dioxide detection unit based on the non-dispersive infrared principle or the TDLAS principle, so that the two detection units can share a micro gas chamber, thereby ensuring the detection accuracy of respiratory gas and achieving a rapid response in milliseconds.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a micro optical gas sensor. Background Art

[0002] Oxygen consumption measurement is an important indicator for accurately assessing human cardiopulmonary function. The oxygen breathed by the human body is transported to the lungs through the blood circulation to participate in human metabolism, and the carbon dioxide produced is discharged from the body through respiratory movement. As a metabolic product of the human body, the concentration of respiratory carbon dioxide has been considered to be the same basic vital signs as body temperature, respiration, pulse, blood pressure, arterial oxygen saturation, etc. It is widely used in fields such as anesthesia monitoring, intensive care, and lung function assessment. Therefore, the detection of respiratory oxygen and carbon dioxide is of great significance in medicine.

[0003] In clinical practice, the basic requirements for sensors that measure respiratory gases (such as oxygen and carbon dioxide) are: first, they must be small in size and light in weight so that the subject does not feel discomfort when measuring in the respiratory tract; second, they must have a fast response time, that is, when the subject inhales or exhales gas at a certain breathing rhythm, the sensor must have a very short time resolution for the gas, so that the subject's breath-by-breath analysis can be performed continuously. Currently, most oxygen sensors and carbon dioxide sensors suitable for clinical respiratory monitoring applications on the market use two different principles for separate detection. For example, oxygen sensors mostly use the paramagnetic principle, electrochemical principle, solid electrolyte principle, and tunable laser principle; sensors suitable for detecting respiratory carbon dioxide gas mostly use the non-spectral infrared principle. There are generally two ways to install and configure the sensor's pulmonary function test system. One is to set a micro-mixing chamber, carbon dioxide sensor, oxygen sensor and air pump in series behind the flow sensor at the subject's mouth and nose. After the air pump proportionally extracts the exhaled air into the micro-mixing chamber, the exhaled air passes through the carbon dioxide sensor and oxygen sensor in sequence for detection. This method is suitable for gas analysis devices that do not require high test response speed. The other is to use oxygen sensors and carbon dioxide sensors that can achieve rapid analysis to directly analyze the gas composition of each moment of inhalation and exhalation at the subject's mouth and nose. This places very stringent requirements on the test response speed of the gas sensor. According to the joint statement of the American Thoracic Society (ATS) and the American College of Chest Physicians (ACCP) on cardiopulmonary exercise testing, "ATS Society. ATS / ACCP Statement on Cardiopulmonary Exercise Testing. Am J Respir Crit Care Med Vol. 167, pp. 211–277, 2003. It mentions that the response time for oxygen and carbon dioxide tests needs to be in the millisecond range. Currently, researchers are mostly focused on rapid response to single-component gases. For example, Servomex (UK) has published related patent GB2465565B, which uses the paramagnetic principle to achieve rapid response to oxygen. Although this allows for a compact sensor, the response speed still cannot reach the millisecond level. Furthermore, adding carbon dioxide to achieve a compact sensor structure and simultaneously achieving a rapid dual-gas response for oxygen and carbon dioxide poses certain challenges.In the prior art, for example, the respiratory gas analyzer disclosed in Marquette's patent WO2023239283A1 uses a first sensor based on the NDIR infrared principle to measure exhaled carbon dioxide, and a second sensor based on the electrochemical or paramagnetic principle to measure oxygen; and General Electric's patent US20130023782A1 also discloses the use of a luminescence quenching principle sensor to measure oxygen and an NDIR infrared principle sensor to measure CO2. This simple system integration and detection of sensors based on two different principles will result in a large overall size, inconvenient installation, poor compatibility between sensors based on different principles, and the failure to solve problems such as the simultaneous rapid response of oxygen and carbon dioxide gases. Summary of the Invention

[0004] The main purpose of the present invention is to provide a gas sensor for simultaneously detecting oxygen and carbon dioxide, which has a small volume, high test accuracy and fast response.

[0005] To achieve the above objectives, the present invention proposes a micro optical gas sensor for measuring oxygen and carbon dioxide in respiratory gas, the micro optical gas sensor comprising:

[0006] The housing is provided with an air inlet unit and an air outlet unit;

[0007] A micro air chamber is provided in the housing for the flow of respiratory gas to be measured; the micro air chamber is provided with a first light input end, a second light input end, a first light output end, a second light output end, an air inlet, and an air outlet, and the air inlet and the air outlet are respectively connected to the air inlet unit and the air outlet unit of the housing;

[0008] an oxygen detection unit, disposed in the housing, comprising a first light source and a first detector, wherein the first light source is a semiconductor laser light source, configured to emit a first light beam to a first light input end of the micro air chamber, and the first detector is configured to receive the light beam emitted from the first light output end of the micro air chamber and generate a first detection signal;

[0009] a carbon dioxide detection unit, disposed in the housing, comprising a second light source and a second detector, wherein the second light source is a non-dispersive infrared light source or a semiconductor laser light source, and is configured to emit a second light beam to a second light input end of the micro gas chamber, and the second detector is configured to receive the light beam emitted from the second light output end of the micro gas chamber and generate a second detection signal; and

[0010] a control processing unit, electrically connected to the first light source, the second light source, the first detector, and the second detector, for controlling the first light source to emit the first light beam and receiving and processing a first detection signal transmitted from the first detector to obtain an oxygen concentration, and for controlling the second light source to emit the second light beam and receiving and processing a second detection signal transmitted from the second detector to obtain a carbon dioxide concentration.

[0011] Furthermore, the volume of the micro air chamber is 0.5ml~3ml.

[0012] Furthermore, the second light source is a non-dispersive infrared light source; the first light input end and the first light output end are located at both ends of the micro air chamber in the length direction thereof, so that the first light beam emitted by the first light source enters the micro air chamber through the first light input end and is received by the first detector through the first light output end;

[0013] The second light input end and the second light output end are located at relative positions in the width direction of the micro air chamber, so that the second light beam emitted by the second light source enters the micro air chamber through the second light input end and is received by the second detector through the second light output end.

[0014] Furthermore, the micro air chamber includes a first concave reflector and a second concave reflector arranged at both ends in the length direction thereof; the first light input end is arranged on the first concave reflector, and the first light output end is arranged on the second concave reflector, so that the first light beam incident from the first light input end is reflected multiple times by the first concave reflector and the second concave reflector and then emitted through the first light output end.

[0015] Furthermore, the micro air chamber also includes two limiting plug-ins respectively arranged on the first concave reflector and the second concave reflector to reduce the redundant volume in the micro air chamber; there is a gap between the two limiting plug-ins for the detection light path of the carbon dioxide detection unit to pass through.

[0016] Furthermore, the air inlet unit and the air outlet unit are spaced apart along the length direction of the micro air chamber, and are arranged on both sides of the micro air chamber in its width direction, so that after the respiratory gas to be tested enters the micro air chamber through the air inlet unit, it flows along the tangent direction of the inner wall curved surface of the micro air chamber and finally flows out from the air outlet unit.

[0017] Furthermore, the second light source is a semiconductor laser light source; the first light input end and the second light input end are located at the first end of the micro air chamber in the length direction, and the first light output end and the second light output end are located at the second end of the micro air chamber in the length direction; or, the second light source is a semiconductor laser light source, the first light input end and the second light output end are located at the first end of the micro air chamber in the length direction, and the second light input end and the first light output end are located at the second end of the micro air chamber in the length direction.

[0018] Furthermore, the inner diameter of the micro air chamber is 2-6 mm.

[0019] Furthermore, the micro optical gas sensor further includes a first semi-transparent and a second semi-transparent and a semi-reflective mirror disposed at both ends of the micro gas chamber in the longitudinal direction, so that light emitted by the first light source passes through the first semi-transparent and semi-reflective mirror and enters the micro gas chamber through the first light input end, is emitted through the first light output end and passes through the second semi-transparent and semi-reflective mirror and is received by the first detector, thereby forming a detection optical path for the oxygen detection unit;

[0020] The light emitted by the second light source is reflected by the first semi-transparent and semi-reflective mirror, enters the micro air chamber through the second light input end, is emitted through the second light output end, and then reflected by the second semi-transparent and semi-reflective mirror to be received by the second detector, thereby forming a detection light path of the carbon dioxide detection unit.

[0021] Furthermore, a collimating lens is provided at the first light source and the second light source respectively; and a focusing lens is provided at the first detector and the second detector respectively.

[0022] Furthermore, the micro optical gas sensor also includes a first packaging structure and a second packaging structure located at both ends of the micro gas chamber, the first packaging structure includes one of the first light source and the first detector, and one of the second light source and the second detector, and the second packaging structure includes the first light source and the other of the first detector, and the second light source and the other of the second detector.

[0023] Furthermore, the first light input end, the second light input end and the first packaging structure are located at the first end of the micro air chamber, and the first packaging structure includes the first light source and the second light source;

[0024] The first light output end and the second light output end are located at a second end of the micro air cavity, and the second packaging structure includes the first detector and the second detector.

[0025] Furthermore, the first packaging structure further includes a first tube base, a first tube cap, a first carrier, a first NTC element, a first TEC element, a second carrier, a second NTC element, a second TEC element, a first baffle, a first lens, and a second lens, wherein the first tube cap is provided on the first tube base, the first carrier and the second carrier are provided side by side on the first tube base, the first baffle is provided between the first carrier and the second carrier, the first light source is provided on the first carrier, the second light source is provided on the second carrier, the first and second NTC elements are provided on the first carrier, respectively, the first and second TEC elements are connected to the first carrier, respectively, the first tube cap has a first through hole corresponding to the first light source, and has a second through hole corresponding to the second light source, the first lens is provided in the first through hole, and the second lens is provided in the second through hole;

[0026] The second packaging structure also includes a second tube seat, a second tube cap, a first pad, a second pad, a second baffle, a third lens and a fourth lens. The second tube cap is arranged on the second tube seat. The first pad and the second pad are arranged side by side on the second tube seat. The second baffle is arranged between the first pad and the second pad. The first detector is arranged on the first pad, and the second detector is arranged on the second pad. The second tube cap has a third through hole corresponding to the first detector and a fourth through hole corresponding to the second detector. The third lens is arranged in the third through hole, and the fourth lens is arranged in the fourth through hole.

[0027] Furthermore, the first light input end, the second light output end and the first packaging structure are located at the first end of the micro air chamber, and the first packaging structure includes the first light source and the second detector;

[0028] The first light output end, the second light input end and the second packaging structure are located at the second end of the micro air chamber, and the second packaging structure includes the second light source and the first detector.

[0029] Furthermore, the first packaging structure further includes a third tube base, a third tube cap, a third carrier, a third NTC element, a third TEC element, a third spacer, a third baffle, a fifth lens, and a sixth lens. The third tube cap is provided on the third tube base, the third NTC element is provided on the third carrier, the third TEC element is connected to the third carrier, the third carrier and the third spacer are provided side by side on the third tube base, the third baffle is provided between the third carrier and the third spacer, the first light source is provided on the third carrier, the second detector is provided on the third spacer, the third tube cap has a fifth through hole corresponding to the first light source, and has a sixth through hole corresponding to the second detector, the fifth lens is provided in the fifth through hole, and the sixth lens is provided in the sixth through hole.

[0030] The second packaging structure also includes a fourth tube base, a fourth tube cap, a fourth carrier, a fourth NTC element, a fourth TEC element, a fourth pad, a fourth baffle, a seventh lens and an eighth lens. The fourth tube cap is provided on the fourth tube base, the fourth NTC element is provided on the third carrier, the fourth TEC element is connected to the fourth carrier, the fourth carrier and the fourth pad are provided side by side on the fourth tube base, the fourth baffle is provided between the fourth carrier and the fourth pad, the second light source is provided on the fourth carrier, the first detector is provided on the fourth pad, the fourth tube cap has a seventh through hole corresponding to the second light source, and has an eighth through hole corresponding to the first detector, the seventh lens is provided in the seventh through hole, and the eighth lens is provided in the eighth through hole.

[0031] The technical solution of the present invention designs a miniature optical gas sensor to simultaneously detect oxygen and carbon dioxide, the main components of medical respiratory gas. By miniaturizing and integrating the oxygen detection unit based on the TDLAS principle and the carbon dioxide detection unit based on the non-dispersive infrared principle or the TDLAS principle, the two detection units can share a miniature gas chamber, thereby ensuring the detection accuracy of respiratory gas and achieving a rapid response to the two component gases of oxygen and carbon dioxide, meeting the millisecond-level response requirements of medical standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1A cross-sectional view of a first embodiment of a gas sensor provided by the present invention;

[0034] Figure 2 for Figure 1 Schematic diagram of part of the structure of the gas sensor;

[0035] Figure 3 This is a simulation diagram of the flow field of the gas to be measured in the micro gas chamber in the first embodiment;

[0036] Figure 4 This is a structural diagram of another embodiment of the first embodiment;

[0037] Figure 5 A schematic structural diagram of a second embodiment of a gas sensor provided by the present invention;

[0038] Figure 6 A schematic structural diagram of a third embodiment of a gas sensor provided by the present invention;

[0039] Figure 7 A schematic structural diagram of a fourth embodiment of a gas sensor provided by the present invention;

[0040] Figure 8 for Figure 6 A schematic structural diagram of the first sealing structure in FIG.

[0041] Figure 9 for Figure 6 A schematic structural diagram of the second sealing structure in FIG.

[0042] Figure 10 for Figure 7 A schematic structural diagram of the first sealing structure in FIG.

[0043] Figure 11 for Figure 7 Schematic diagram of the structure of the second sealing structure.

[0044] Description of Figure Numbers:

[0045] 100. Micro optical gas sensor;

[0046] 1. Shell, 11. Air inlet, 12. Air outlet;

[0047] 2. Micro air chamber, 21. First concave reflector, 22. Second concave reflector, 23. Limiting plug-in, 231. Root, 232. Head;

[0048] 3. Oxygen detection unit, 31. First light source, 32. First detector;

[0049] 4. Carbon dioxide detection unit, 41. Second light source, 42. Second detector;

[0050] 5. Spotlight;

[0051] 6. Semi-transparent and semi-reflective mirror;

[0052] 7a, first tube base, 7b, first tube cap, 7c, first carrier plate, 7d, second carrier plate, 7e, first baffle, 7f, first lens, 7g, second lens, 7h, first NTC element, 7i, second NTC element, 7j, first TEC element, 7k, second TEC element;

[0053] 8a, second tube base, 8b, second tube cap, 8c, first gasket, 8d, second gasket, 8e, second baffle, 8f, third lens, 8g, fourth lens;

[0054] 9a, third tube base, 9b, third tube cap, 9c, third carrier board, 9d, third spacer, 9e, third baffle, 9f, fifth lens, 9g, sixth lens, 9h, third NTC element, 9i, third TEC element;

[0055] 10a, fourth tube holder, 10b, fourth tube cap, 10c, fourth carrier board, 10d, fourth spacer, 10e, fourth baffle, 10f, seventh lens, 10g, eighth lens, 10h, fourth NTC element, 10i, fourth TEC element.

[0056] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0057] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0058] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0059] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0060] Existing oxygen sensors and carbon dioxide sensors suitable for clinical respiratory monitoring applications mostly use two different principles of sensors for separate detection. For example, oxygen sensors mostly use the paramagnetic principle, electrochemical principle, solid electrolyte principle, and tunable laser principle; sensors suitable for detecting respiratory carbon dioxide gas mostly use the non-spectral infrared principle. There are generally two ways to install and configure the sensor's pulmonary function test system. One is to set a micro-mixing chamber, carbon dioxide sensor, oxygen sensor and air pump in series behind the flow sensor at the subject's mouth and nose. After the air pump proportionally draws the exhaled air into the micro-mixing chamber, the exhaled air is successively detected by the carbon dioxide sensor and the oxygen sensor. This method is suitable for gas analysis devices that do not require high test response speed; the other is to use oxygen sensors and carbon dioxide sensors that can quickly analyze, and directly analyze the gas composition at every moment of inhalation and exhalation at the subject's mouth and nose. This has very demanding requirements on the test response speed of the gas sensor. Currently, researchers are mostly conducting research on the rapid response of single-component gases. However, it is very difficult to add the carbon dioxide component to achieve a compact sensor structure and rapid dual-gas response. Moreover, simple system integration and testing of two sensors based on different principles will result in a large overall volume, inconvenient installation, and poor compatibility between sensors based on different principles. It is very challenging to achieve simultaneous rapid response of both oxygen and carbon dioxide gases in the same gas sensor.

[0061] In view of this, the present invention provides a micro optical gas sensor 100 for measuring oxygen and carbon dioxide. The micro optical gas sensor 100 includes a shell 1, a micro gas chamber 2, an oxygen detection unit 3, a carbon dioxide detection unit 4 and a control processing unit. The shell 1 is provided with an air inlet unit and an air outlet unit; the micro gas chamber 2 is arranged in the shell 1, and is connected to the air inlet unit and the air outlet 12 through an air inlet 11 and an air outlet 12; the oxygen detection unit 3 is arranged in the shell 1, and includes a first light source 31 and a first detector 32. The first light source 31 is a semiconductor laser light source, which is used to emit a first light beam to the first light input end of the micro gas chamber 2, and the first detector 32 is used to receive the light beam emitted from the first light output end of the micro gas chamber 2 and generate a first detection signal; the carbon dioxide The carbon detection unit 4 is provided in the housing 1 and includes a second light source 41 and a second detector 42. The second light source 41 is a non-dispersive infrared light source or a semiconductor laser light source, and is used to emit a second light beam to the second light input end of the micro gas chamber 2. The second detector 42 is used to receive the light beam emitted from the second light output end of the micro gas chamber 2 and generate a second detection signal; the control processing unit is electrically connected to the first light source 31, the second light source 41, the first detector 32, and the second detector 42, and is used to control the first light source 31 to emit the first light beam and receive and process the first detection signal transmitted from the first detector 32 to obtain the oxygen concentration, and control the second light source 41 to emit the second light beam and receive and process the second detection signal transmitted from the second detector 42 to obtain the carbon dioxide concentration.

[0062] In the first embodiment of the technical solution of the present invention, as Figure 1 As shown, the oxygen detection unit 3 adopts the TDLAS principle to detect the oxygen concentration, the first light source 31 adopts a TDLAS laser light source, and the wavelength of the oxygen absorption light emitted by the tunable method is 763nm; the carbon dioxide detection unit 4 adopts the non-dispersive infrared principle to detect the carbon dioxide concentration, the second light source 41 adopts a non-dispersive infrared light source, and the second detector 42 adopts a single measurement channel or a dual-channel setting with a reference channel, wherein the filter wavelength of carbon dioxide is 4.26μm, thereby realizing the simultaneous detection of oxygen and carbon dioxide.

[0063] It should be noted that the air inlet unit adopts the form of an air inlet cannula to introduce the gas to be tested into the micro air chamber 2 through the air inlet 11, one end of which is connected to the air warehouse, and the other end is connected to the micro air chamber 2. The air outlet unit adopts the form of an air outlet cannula to discharge the gas in the micro air chamber 2 to the outside through the air outlet 12, one end of which is connected to the air warehouse, and the other end is connected to the micro air chamber 2.

[0064] The volume of the micro air chamber 2 is 0.5ml~3ml. It should be noted that the volume of the micro air chamber 2 in this embodiment is 0.56ml. The oxygen detection unit 3 and the carbon dioxide detection unit 4 share the same micro air chamber 2 for detection.

[0065] Specifically, in the present invention, the positions of the first light input end, the second light input end, the first light output end, and the second light output end of the micro air chamber 2 are not limited, wherein the first light input end and the first light output end can be located at both ends of the micro air chamber 2 in its length direction, and the second light input end and the second light output end are located at opposite positions of the micro air chamber in its width direction. In this embodiment, as Figure 2 As shown, the micro air chamber 2 specifically includes a first concave reflector 21 and a second concave reflector 22 provided at both ends in the longitudinal direction thereof. The distance between the two reflective mirrors is 15 mm, and the curvature radius is also the same, about 12 mm. The first light input end is provided on the first concave reflector 21, and the first light output end is provided on the second concave reflector 22, so that a first light beam incident from the first light input end is reflected multiple times by the first concave reflector 21 and the second concave reflector 22 and then emitted through the first light output end, forming a detection light path for the oxygen detection unit 3, thereby ensuring the detection light path under a limited chamber volume. The second light input end and the second light output end are located at relative positions of the micro air chamber 2 in the width direction thereof, so that a second light beam incident from the second light input end is emitted through the second light output end, forming a detection light path for the carbon dioxide detection unit 4.

[0066] Thus, in this embodiment, an oxygen detection unit 3 with a long optical path is arranged in the length direction of the micro gas chamber 2, and a carbon dioxide detection unit 4 with a short optical path is arranged in the width direction. The two detection units share one micro gas chamber, which ensures the accuracy of two-component gas detection while achieving rapid response, and the overall sensor volume is more compact.

[0067] In this embodiment, in order to improve the response speed of the gas, the redundant volume of the gas chamber can be further reduced to improve the effective utilization rate of the micro gas chamber. Therefore, the effective flow volume of the gas to be measured in the micro gas chamber will be less than 0.5 ml. Specifically, two limiting plug-ins 23 are set on the two concave reflectors of the micro gas chamber 2, one of the two limiting plug-ins 23 is set on the first concave reflector 21, and the other is set on the second concave reflector 222, which is used to reduce the redundant volume in the micro gas chamber 2, and there is a gap between the two limiting plug-ins 23 for the detection light path of the carbon dioxide detection unit 4 to pass through.

[0068] In this way, by arranging two limiting plugs 23 in the micro gas chamber 2, the flow range of the gas to be measured entering the cavity 21 is limited, and both the oxygen measuring beam and the carbon dioxide measuring beam can fully interact with the gas to be measured, thereby shortening the response time.

[0069] It should be noted that the shape of the limiting plug 23 is not limited. For details, please refer to Figure 2 In the first embodiment of the present invention, each limiting plug 23 has a root portion 231 and a head portion 232. The root portion 231 is located at the end of the cavity 21 and passes through a reflector. The head portion 232 is located near the middle of the cavity 21. Each limiting plug 23 is tapered from its root portion 231 to its head portion 232. More specifically, the limiting plug 23 is truncated cone-shaped.

[0070] Further, see Figure 1 In the first embodiment of the present invention, the air inlet 11 and the air outlet 12 of the micro air chamber 2 are spaced apart along the length direction of the micro air chamber 2 and are respectively arranged on both sides of the micro air chamber 2 in the width direction, so that the respiratory gas to be measured flowing into the micro air chamber 2 from the air inlet unit flows along the tangent direction of the inner wall curved surface of the micro air chamber 2 and finally flows out from the air outlet unit. Figure 3 The flow field simulation diagram of the gas to be tested in the micro gas chamber of this embodiment is shown. In this way, the gas to be tested can spirally advance in the cavity 21, so that the gas to be tested not only flows without obstruction, but also fills the entire cavity 21 quickly and without dead zones, further improving the response time.

[0071] In the first embodiment of the present invention, the micro optical gas sensor 100 further includes a first mounting seat and a second mounting seat provided on the housing 1, one of the first concave reflector 21 and the second concave reflector 22 and the first light source 31 are mounted on the first mounting seat, the other of the first concave reflector 221 and the second concave reflector 222 and the first detector 32 are mounted on the second mounting seat, and the limiting plug-in 23 is mounted on the first mounting seat and / or the second mounting seat.

[0072] It should be noted that, in the present invention, the connection method between each reflector and its corresponding mounting seat is not limited, and can be bonding, clamping, etc.

[0073] For details, please refer to Figure 1 In the first embodiment of the present invention, a focusing cover 5 is provided on the light emitting side of the second light source 41 so that the second light beam emitted by the divergent non-dispersive infrared light source can reach the second detector 42 as much as possible.

[0074] Specifically, in the first embodiment of the present invention, the micro optical gas sensor 100 further includes a heating component, which includes a heater and a thermal insulation component (such as thermal insulation cotton). The heater is provided in the shell 1 and is electrically connected to the control processing unit, and the thermal insulation component is wrapped around the outer periphery of the shell 1. In this way, heating is performed by the heater, and the temperature of the first concave reflector 21, the second concave reflector 22 and the inner wall of the micro gas chamber 2 is quickly increased by the thermal insulation component to prevent condensation of the reflector and the inner wall of the gas chamber, thereby ensuring the normal operation of the micro optical gas sensor 100 and ensuring detection stability and accuracy.

[0075] In the present invention, optical noise is a negative factor affecting the detection accuracy of the TDLAS principle sensor, and a major source of optical noise is generated by multiple reflections of the detection light on the reflector. Therefore, in another embodiment of the present invention, Figure 4 As shown, the oxygen detection unit 3 adopts a counter-beam optical path structure. In this way, the micro gas chamber 2 is longer than the micro gas chamber 2 of the first embodiment of the present invention in terms of length and is designed to be smaller in width. After the first light source 31 enters the micro gas chamber 2 through the first light input end, it is directly output through the first light output end at the other end and received by the first detector 41. In this way, although the overall volume of the sensor will be increased to a certain extent, the gas response speed can still be guaranteed, and the optical noise detected by the sensor can also be reduced.

[0076] In the second embodiment of the present invention, the carbon dioxide detection unit originally using the non-spectral infrared principle is replaced with a carbon dioxide detection unit using the TDLAS principle. Specifically, Figure 5As shown, the second light source 41 is a semiconductor laser light source. When detecting carbon dioxide, its light absorption wavelength is 1573nm. Since both gas components are detected using the TDLAS principle, and the laser beam diameter can be made and adjusted to be very fine, the inner cavity of the micro gas chamber can be made very fine to reduce the volume of the gas chamber. The inner cavity diameter can be 2~6mm. In this embodiment, the inner cavity diameter is 2.5mm and the volume is 0.5ml. In this embodiment, the first light input end and the second light input end are located at the first end of the micro air chamber 2 in the length direction, the first light output end and the second light output end are located at the second end of the micro air chamber 2 in the length direction, and two semi-transparent and semi-reflective mirrors 6 are further provided at both ends of the micro air chamber 2 in the length direction, so that the light emitted by the first light source 31 passes through the first semi-transparent and semi-reflective mirror and enters the micro air chamber 2 through the first light input end, is emitted through the first light output end and passes through the second semi-transparent and semi-reflective mirror and is received by the first detector 32, thereby forming a detection optical path of the oxygen detection unit, and the light emitted by the second light source 41 passes through the first semi-transparent and semi-reflective mirror and enters the micro air chamber 2 through the second light input end and passes through the second light After being emitted from the output end, it is reflected by the second semi-transparent and semi-reflective mirror and then received by the second detector 42, forming a detection light path of the carbon dioxide detection unit; a collimating lens is further provided at the first light source 31 and the second light source 41, respectively, and a focusing lens is provided at the first detector and the second detector, respectively, so that the first light beam emitted by the first light source 31 and the second light beam emitted by the second light source 41 are collimated into very thin light beams by the collimating lens respectively. Since the light beams are very thin, they can pass through the micro gas chamber 2; by providing the focusing lens, the light incident on the first detector 32 and the second detector 42 is focused, so that more light beams are received, thereby realizing the simultaneous and accurate detection of oxygen and carbon dioxide by the micro optical sensor 100.

[0077] It should be noted that the two semi-transparent and semi-reflective mirrors 6 can allow the light with a wavelength of 763 nm emitted by the first light source 31 to pass normally through the mirror through coating, while reflecting the light with a wavelength of 1573 nm emitted by the second light source 41 .

[0078] In order to further improve the compactness of the overall sensor and obtain a micro optical gas sensor with higher integration, it also includes a first packaging structure and a second packaging structure located at both ends of the micro gas chamber, the first packaging structure includes one of the first light source 31 and the first detector 32, and one of the second light source 41 and the second detector 42, and the second packaging structure includes the other of the first light source 31 and the first detector 32, and the other of the second light source 41 and the second detector 42.

[0079] In this way, packaging can be performed according to actual needs, specifically including the following four packaging situations: 1. The first packaging structure includes the first light source 31 and the second light source 41, and the second packaging structure includes the first detector 32 and the second detector 42; 2. The first packaging structure includes the first light source 31 and the second detector 42, and the second packaging structure includes the first detector 32 and the second light source 41; 3. The first packaging structure includes the first detector 32 and the second light source 41, and the second packaging structure includes the first light source 31 and the second detector 42; 4. The first packaging structure includes the first detector 32 and the second detector 42, and the second packaging structure includes the first light source 31 and the second light source 41.

[0080] More specifically, in the third embodiment of the present invention, the oxygen detection unit 3 and the carbon dioxide detection unit 4 are integrated, the first light source 31 and the second light source 41 are integrated into a first packaging structure, and the first detector 32 and the second detector 42 are integrated into a second packaging structure. Specifically, Figure 6 As shown, the inner cavity of the micro air chamber has a diameter of 3.5 mm and a volume of 1 ml. The first light input end, the second light input end, and the first packaging structure are located at the first end of the micro air chamber 2; the first light output end, the second light output end, and the second packaging structure are located at the second end of the micro air chamber 2. In this way, the first packaging structure can simultaneously emit the first and second light beams, that is, simultaneously emit the absorption light of oxygen and carbon dioxide, and the second packaging structure can simultaneously receive the first and second light beams, that is, simultaneously receive the absorption light signals of oxygen and carbon dioxide.

[0081] Furthermore, Figure 8 and Figure 9The first packaging structure and the second packaging structure are shown. The first packaging structure also includes a first tube base 7a, a first tube cap 7b, a first NCT element 7h, a first TEC element 7j, a first carrier 7c, a second carrier 7d, a second NTC element 7i, a second TEC element 7k, a first baffle 7e, a first lens 7f and a second lens 7g. The first tube cap 7b is covered on the first tube base 7a. The first carrier 7c and the second carrier 7d are arranged side by side on the first tube base 7a. The first and second NTC elements are respectively arranged on the first carrier 7c and the second carrier 7d through conductive silver glue. The first TEC element 7j and the second TEC element 7k Each of the first and second TEC elements 7a is fixedly mounted on the first tube base 7a using highly thermally conductive adhesive. The first TEC element 7j is connected to the first carrier plate 7c, and the second TEC element 7k is connected to the second carrier plate 7d. The first baffle 7e is positioned between the first and second carrier plates 7c, 7d. The first light source 31 is positioned on the first carrier plate 7c, and the second light source 41 is positioned on the second carrier plate 7d. The first tube cap 7b has a first through hole corresponding to the first light source 31 and a second through hole corresponding to the second light source 41. The first lens 7f is positioned in the first through hole, and the second lens 7g is positioned in the second through hole. The first baffle 7e separates the first and second light sources 31, 41, preventing interference caused by crosstalk. Furthermore, the first and second lenses 7f and 7g collimate the first and second light beams emitted by the first and second light sources 31 and 41, forming very small beams.

[0082] The second packaging structure further includes a second tube base 8a, a second tube cap 8b, a first gasket 8c, a second gasket 8d, a second baffle 8e, a third lens 8f, and a fourth lens 8g. The second tube cap 8b is mounted on the second tube base 8a. The first gasket 8c and the second gasket 8d are arranged side by side on the second tube base 8a. The second baffle 8e is positioned between the first gasket 8c and the second gasket 8d. The first detector 32 is positioned on the first gasket 8c, and the second detector 42 is positioned on the second gasket 8d. The second tube cap 8b defines a third through hole corresponding to the first detector 32 and a fourth through hole corresponding to the second detector 42. The third lens 8f is positioned in the third through hole, and the fourth lens 8g is positioned in the fourth through hole. The second baffle 8e can separate the first detector 32 and the second detector 42 to prevent interference caused by crosstalk. At the same time, by providing the third lens 8f and the fourth lens 8g, the light incident on the first detector 32 and the second detector 42 is focused, so that more light beams are received.

[0083] It should be noted that the second lens 7g and the fourth lens 8g are respectively coated so that the second light beam with a wavelength of 1573nm emitted by the second light source 41 can pass through, while the first light beam with a wavelength of 763nm emitted by the first light source 31 cannot pass through, and the first lens 7f and the third lens 8f are respectively coated so that the first light beam with a wavelength of 763nm emitted by the first light source 31 can pass through, while the second light beam with a wavelength of 1573nm emitted by the second light source 41 cannot pass through, thereby preventing possible interference between the two beams of light.

[0084] It should also be noted that the first light source 31 and the second light source 41 are both laser chips, and are fixed to the first carrier 7c and the second carrier 7d in a one-to-one correspondence through eutectic bonding. Similarly, the first detector 32 and the second detector 42 are both detection chips, and are fixed to the first cushion block 8c and the second cushion block 8d in a one-to-one correspondence.

[0085] In the fourth embodiment of the present invention, different from the third embodiment, as shown in FIG. Figure 7 As shown, the first light source 31 and the second detector 42 are integrated into a first packaging structure, and the second light source 41 and the first detector 32 are integrated into a second packaging structure accordingly, so that both ends of the optical path are both transmitting and receiving, and the first light beam can be received while the second light beam is emitted, and the second light beam can be received while the first light beam is emitted, thereby realizing simultaneous and rapid detection of oxygen and carbon dioxide.

[0086] Figure 10The first packaging structure is shown, which specifically includes a third tube base 9a, a third tube cap 9b, a third carrier plate 9c, a third NTC element 9h, a third TEC element 9i, a third pad 9d, a third baffle 9e, a fifth lens 9f and a sixth lens 9g. The third tube cap 9b is covered on the third tube base 9a, and the third carrier plate 9c and the third pad 9d are arranged side by side on the third tube base 9a. The third baffle 9e is arranged between the third carrier plate 9c and the third pad 9d. The first light source 31 is arranged on the third carrier plate 9c. The third NTC element 9h is connected to the TEC element 9i. Conductive silver glue is applied to the third carrier plate 9c. The third NTC element 9h is also attached to the third carrier plate 9c via conductive silver glue. The third TEC element 9i is fixed to the third tube base 9a via highly thermally conductive glue and connected to the third carrier plate 9c via the highly thermally conductive glue. The second detector 42 is mounted on the third spacer 9d. The third tube cap 9b has a fifth through-hole corresponding to the first light source 31 and a sixth through-hole corresponding to the second detector 42. The fifth lens 9f is positioned in the fifth through-hole, and the sixth lens 9g is positioned in the sixth through-hole. Thus, the third baffle 9e separates the first light source 31 and the second detector 42, preventing interference caused by crosstalk. Furthermore, the fifth lens 9f collimates the first light beam emitted by the first light source 31, forming a very small beam. The sixth lens 9g focuses the light incident on the second detector 42, ensuring that more of the beam is received.

[0087] Figure 11The second packaging structure is shown as an example. The second packaging structure further includes a fourth tube base 10a, a fourth tube cap 10b, a fourth carrier 10c, a fourth NTC element 10h, a fourth TEC element 10i, a fourth spacer 10d, a fourth baffle 10e, a seventh lens 10f, and an eighth lens 10g. The fourth tube cap 10b is covered on the fourth tube base 10a. The fourth carrier 10c and the fourth spacer 10d are arranged side by side on the fourth tube base 10a. The fourth baffle 10e is arranged between the fourth carrier 10c and the fourth spacer 10d. The second light source 41 is arranged on the fourth carrier 10c. The fourth NTC element 10h is a first element of the TEC element 10i. The fourth spacer 10d is a second element of the TEC element 10i. The C element 10h is mounted on the fourth carrier board 10c using conductive silver glue. The fourth NTC element 10h is also mounted on the fourth carrier board 10c using conductive silver glue. The fourth TEC element 10i is fixed to the fourth tube base 10a using highly thermally conductive glue and is connected to the fourth carrier board 10c via the highly thermally conductive glue. The first detector 32 is mounted on the fourth spacer 10d. The fourth cap 10b has a seventh through hole corresponding to the second light source 41 and an eighth through hole corresponding to the first detector 32. The seventh lens 10f is positioned in the seventh through hole, and the eighth lens 10g is positioned in the eighth through hole. Thus, the fourth baffle 10e separates the second light source 41 and the first detector 32, preventing interference caused by crosstalk. Furthermore, the seventh lens 10f collimates the second light beam emitted by the second light source 41, forming a very small beam. The eighth lens 10g focuses the light incident on the first detector 32, ensuring that more of the beam is received.

[0088] It should be noted that the seventh lens 10f and the sixth lens 9g are respectively coated so that the second light beam with a wavelength of 1573nm emitted by the second light source 41 can pass therethrough, while the first light beam with a wavelength of 763nm emitted by the first light source 31 cannot pass therethrough. Furthermore, the fifth lens 9f and the eighth lens 10g are respectively coated so that the first light beam with a wavelength of 763nm emitted by the first light source 31 can pass therethrough, while the second light beam with a wavelength of 1573nm emitted by the second light source 41 cannot pass therethrough. This prevents possible interference between the two light beams.

[0089] It should also be noted that the first light source 31 and the second light source 41 are both laser chips, and are fixed to the third carrier 9c and the fourth carrier 10c in a one-to-one correspondence via eutectic bonding. Similarly, the first detector 32 and the second detector 42 are both detection chips, and are fixed to the third cushion block 9d and the fourth cushion block 10d in a one-to-one correspondence.

[0090] In the third and fourth embodiments of the present invention, the micro optical gas sensor 100 further includes a first driving circuit board and a second driving circuit board, wherein the first driving circuit board is electrically connected to the first light source 31, the second light source 41, and the control processing unit, and the second driving circuit board is electrically connected to the first detector 32, the second detector 42, and the control processing unit.

[0091] Both the third and fourth embodiments of the present invention are in an integrated packaging form, so that the overall sensor size can be made smaller, the optical path is simple and easy to implement, and the cost is low; the oxygen detection unit 3 and the carbon dioxide detection unit 4 both use a basic opposite-beam method in the micro gas chamber 2 to realize gas detection, without the need for multiple return steps, and have a fast response speed.

[0092] A comparative test experiment was conducted using the sensors provided by various embodiments of the present invention and a sensor using a traditional Herriott cell. The test gases (oxygen and carbon dioxide) were introduced into the absorption cell at a set flow rate. A serial port tool was used to record the sensor raw data, and the sensor response time from air to the range point T90 was calculated. The experimental results are shown in Table 1 below:

[0093] Table 1 Fast response time under different flow rates in various embodiments Unit: ms

[0094]

[0095] It can be concluded that under the same test conditions, compared with the existing paramagnetic oxygen sensor / TDLAS laser oxygen sensor and non-spectroscopy infrared sensor in series combination for measuring oxygen and carbon dioxide in respiratory gas, at the same flow rate, the response speed of the micro-optical gas sensor 100 provided by each embodiment of the present invention is significantly faster, and it has more advantages as a medical respiratory gas sensor, that is, it can achieve miniaturized design and high-precision measurement while also achieving fast response, greatly improving practicality.

[0096] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the inventive concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A miniature optical gas sensor for measuring oxygen and carbon dioxide in respiratory gas, characterized in that: The micro optical gas sensor comprises: The housing is provided with an air inlet unit and an air outlet unit; A micro air chamber is provided in the housing for the flow of respiratory gas to be measured; the micro air chamber is provided with a first light input end, a second light input end, a first light output end, a second light output end, an air inlet, and an air outlet, and the air inlet and the air outlet are respectively connected to the air inlet unit and the air outlet unit of the housing; an oxygen detection unit, disposed in the housing, comprising a first light source and a first detector, wherein the first light source is a semiconductor laser light source, configured to emit a first light beam to a first light input end of the micro air chamber, and the first detector is configured to receive the light beam emitted from the first light output end of the micro air chamber and generate a first detection signal; a carbon dioxide detection unit, disposed in the housing, comprising a second light source and a second detector, wherein the second light source is a non-dispersive infrared light source, configured to emit a second light beam to a second light input end of the micro air chamber, and the second detector is configured to receive the light beam emitted from the second light output end of the micro air chamber and generate a second detection signal; and a control processing unit, electrically connected to the first light source, the second light source, the first detector, and the second detector, configured to control the first light source to emit the first light beam and receive and process a first detection signal transmitted from the first detector to obtain an oxygen concentration, and to control the second light source to emit the second light beam and receive and process a second detection signal transmitted from the second detector to obtain a carbon dioxide concentration; The volume of the micro air chamber is 0.5ml~3ml; The first light input end and the first light output end are located at two ends of the micro air chamber in the length direction thereof, so that the first light beam emitted by the first light source enters the micro air chamber through the first light input end and is received by the first detector through the first light output end; The second light input end and the second light output end are located at relative positions in the width direction of the micro air chamber, so that the second light beam emitted by the second light source enters the micro air chamber through the second light input end and is received by the second detector through the second light output end.

2. A micro optical gas sensor according to claim 1, characterized in that: The micro air chamber includes a first concave reflector and a second concave reflector arranged at both ends in the length direction of the micro air chamber; the first light input end is arranged on the first concave reflector, and the first light output end is arranged on the second concave reflector, so that the first light beam incident from the first light input end is reflected multiple times by the first concave reflector and the second concave reflector and then emitted through the first light output end.

3. A micro optical gas sensor according to claim 2, characterized in that: The micro air chamber further includes two limiting plug-ins respectively arranged on the first concave reflector and the second concave reflector to reduce the redundant volume in the micro air chamber; a gap is provided between the two limiting plug-ins for the detection light path of the carbon dioxide detection unit to pass through.

4. A micro optical gas sensor according to any one of claims 1 to 3, characterized in that: The air inlet and air outlet of the micro air chamber are arranged at intervals along the length direction of the micro air chamber and are respectively arranged on both sides of the micro air chamber in the width direction, so that after the respiratory gas to be measured enters the micro air chamber through the air inlet unit, it flows along the tangent direction of the inner wall curved surface of the micro air chamber and finally flows out from the air outlet unit.

5. A miniature optical gas sensor for measuring oxygen and carbon dioxide in respiratory gas, characterized in that: The micro optical gas sensor comprises: The housing is provided with an air inlet unit and an air outlet unit; A micro air chamber is provided in the housing for the flow of respiratory gas to be measured; the micro air chamber is provided with a first light input end, a second light input end, a first light output end, a second light output end, an air inlet, and an air outlet, and the air inlet and the air outlet are respectively connected to the air inlet unit and the air outlet unit of the housing; an oxygen detection unit, disposed in the housing, comprising a first light source and a first detector, wherein the first light source is a semiconductor laser light source, configured to emit a first light beam to a first light input end of the micro air chamber, and the first detector is configured to receive the light beam emitted from the first light output end of the micro air chamber and generate a first detection signal; a carbon dioxide detection unit, disposed in the housing, comprising a second light source and a second detector, wherein the second light source is a semiconductor laser light source, configured to emit a second light beam to a second light input end of the micro gas chamber, and the second detector is configured to receive the light beam emitted from the second light output end of the micro gas chamber and generate a second detection signal; and a control processing unit, electrically connected to the first light source, the second light source, the first detector, and the second detector, configured to control the first light source to emit the first light beam and receive and process a first detection signal transmitted from the first detector to obtain an oxygen concentration, and to control the second light source to emit the second light beam and receive and process a second detection signal transmitted from the second detector to obtain a carbon dioxide concentration; The first light input end and the second light input end are located at a first end of the micro air chamber in the longitudinal direction, and the first light output end and the second light output end are located at a second end of the micro air chamber in the longitudinal direction; or, the first light input end and the second light output end are located at the first end of the micro air chamber in the longitudinal direction, and the second light input end and the first light output end are located at the second end of the micro air chamber in the longitudinal direction; The inner diameter of the micro air chamber is 2-6 mm; The micro air chamber further includes a first semi-transparent mirror and a second semi-transparent mirror disposed at both ends of the micro air chamber in the longitudinal direction, so that light emitted by the first light source passes through the first semi-transparent mirror and enters the micro air chamber through the first light input end, is emitted through the first light output end, passes through the second semi-transparent mirror, and is received by the first detector, thereby forming a detection optical path for the oxygen detection unit; The light emitted by the second light source is reflected by the first semi-transparent and semi-reflective mirror, enters the micro air chamber through the second light input end, is emitted through the second light output end, and then reflected by the second semi-transparent and semi-reflective mirror to be received by the second detector, thereby forming a detection light path of the carbon dioxide detection unit.

6. A micro optical gas sensor according to claim 5, characterized in that: A collimating lens is respectively provided at the first light source and the second light source; and a focusing lens is respectively provided at the first detector and the second detector.

7. A miniature optical gas sensor for measuring oxygen and carbon dioxide in respiratory gas, characterized in that: The micro optical gas sensor comprises: The housing is provided with an air inlet unit and an air outlet unit; A micro air chamber is provided in the housing for the flow of respiratory gas to be measured; the micro air chamber is provided with a first light input end, a second light input end, a first light output end, a second light output end, an air inlet, and an air outlet, and the air inlet and the air outlet are respectively connected to the air inlet unit and the air outlet unit of the housing; an oxygen detection unit, disposed in the housing, comprising a first light source and a first detector, wherein the first light source is a semiconductor laser light source, configured to emit a first light beam to a first light input end of the micro air chamber, and the first detector is configured to receive the light beam emitted from the first light output end of the micro air chamber and generate a first detection signal; a carbon dioxide detection unit, disposed in the housing, comprising a second light source and a second detector, wherein the second light source is a semiconductor laser light source, configured to emit a second light beam to a second light input end of the micro gas chamber, and the second detector is configured to receive the light beam emitted from the second light output end of the micro gas chamber and generate a second detection signal; and a control processing unit, electrically connected to the first light source, the second light source, the first detector, and the second detector, configured to control the first light source to emit the first light beam and receive and process a first detection signal transmitted from the first detector to obtain an oxygen concentration, and to control the second light source to emit the second light beam and receive and process a second detection signal transmitted from the second detector to obtain a carbon dioxide concentration; The first light input end and the second light input end are located at a first end of the micro air chamber in the longitudinal direction, and the first light output end and the second light output end are located at a second end of the micro air chamber in the longitudinal direction; or, the first light input end and the second light output end are located at the first end of the micro air chamber in the longitudinal direction, and the second light input end and the first light output end are located at the second end of the micro air chamber in the longitudinal direction; The inner diameter of the micro air chamber is 2-6 mm; The micro air chamber further includes a first packaging structure and a second packaging structure located at both ends of the micro air chamber, wherein the first packaging structure includes one of the first light source and the first detector, and one of the second light source and the second detector, and the second packaging structure includes the other of the first light source and the first detector, and the other of the second light source and the second detector.

8. The micro optical gas sensor according to claim 7, characterized in that: The first light input end, the second light input end and the first packaging structure are located at a first end of the micro air cavity, and the first packaging structure includes the first light source and the second light source; The first light output end and the second light output end are located at a second end of the micro air cavity, and the second packaging structure includes the first detector and the second detector.

9. The micro optical gas sensor according to claim 8, characterized in that: The first packaging structure further includes a first tube base, a first tube cap, a first carrier, a first NTC element, a first TEC element, a second carrier, a second NTC element, a second TEC element, a first baffle, a first lens, and a second lens. The first tube cap is provided on the first tube base. The first carrier and the second carrier are provided side by side on the first tube base. The first baffle is provided between the first carrier and the second carrier. The first light source is provided on the first carrier, and the second light source is provided on the second carrier. The first NTC element and the second NTC element are provided on the first carrier, and the first TEC element and the second TEC element are connected to the first carrier, and the second carrier, respectively. The first tube cap has a first through hole corresponding to the first light source and a second through hole corresponding to the second light source. The first lens is provided in the first through hole, and the second lens is provided in the second through hole. The second packaging structure also includes a second tube seat, a second tube cap, a first pad, a second pad, a second baffle, a third lens and a fourth lens. The second tube cap is arranged on the second tube seat. The first pad and the second pad are arranged side by side on the second tube seat. The second baffle is arranged between the first pad and the second pad. The first detector is arranged on the first pad, and the second detector is arranged on the second pad. The second tube cap has a third through hole corresponding to the first detector and a fourth through hole corresponding to the second detector. The third lens is arranged in the third through hole, and the fourth lens is arranged in the fourth through hole.

10. The micro optical gas sensor according to claim 7, characterized in that: The first light input end, the second light output end and the first packaging structure are located at a first end of the micro air chamber, and the first packaging structure includes the first light source and the second detector; The first light output end, the second light input end and the second packaging structure are located at the second end of the micro air chamber, and the second packaging structure includes the second light source and the first detector.

11. The micro optical gas sensor according to claim 10, characterized in that: The first packaging structure further includes a third tube base, a third tube cap, a third carrier, a third NTC element, a third TEC element, a third spacer, a third baffle, a fifth lens, and a sixth lens. The third tube cap is disposed on the third tube base, the third NTC element is disposed on the third carrier, the third TEC element is connected to the third carrier, the third carrier and the third spacer are arranged side by side on the third tube base, the third baffle is disposed between the third carrier and the third spacer, the first light source is disposed on the third carrier, the second detector is disposed on the third spacer, the third tube cap has a fifth through hole corresponding to the first light source, and has a sixth through hole corresponding to the second detector, the fifth lens is disposed in the fifth through hole, and the sixth lens is disposed in the sixth through hole. The second packaging structure also includes a fourth tube base, a fourth tube cap, a fourth carrier, a fourth NTC element, a fourth TEC element, a fourth pad, a fourth baffle, a seventh lens and an eighth lens. The fourth tube cap is provided on the fourth tube base, the fourth NTC element is provided on the third carrier, the fourth TEC element is connected to the fourth carrier, the fourth carrier and the fourth pad are provided side by side on the fourth tube base, the fourth baffle is provided between the fourth carrier and the fourth pad, the second light source is provided on the fourth carrier, the first detector is provided on the fourth pad, the fourth tube cap has a seventh through hole corresponding to the second light source, and has an eighth through hole corresponding to the first detector, the seventh lens is provided in the seventh through hole, and the eighth lens is provided in the eighth through hole.

Images