Electronic nose system and gas detection method

Abstract

The present invention provides an electronic nose system and a gas detection method. The electronic nose system comprises a sampling unit, a detection unit, a pre-concentration unit and a host computer control unit. The sampling unit comprises a sampling module, an air pump and a control panel. The detection unit is connected between the sampling module and the air pump through a pipeline, and can detect the gas flowing through. The pre-concentration unit is connected between the sampling module and the sensor array detection module through a pipeline, and can perform pre-concentration treatment on the gas flowing through. The host computer control unit is connected to the control panel and the detection unit, and the host computer control unit can receive a digital signal to output a qualitative analysis result or a quantitative analysis result of the gas. The electronic nose system can use the host computer control unit to control each valve group on the pipeline, so that the pre-concentration unit is selectively connected to the gas path between the sampling module and the sensor array detection module to provide a pre-concentration function during the detection process.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic noses, and in particular to an electronic nose system with a selectable pre-concentration function and a gas detection method. Background Art

[0002] The exhaled air of lung cancer patients contains many volatile organic compounds (VOCs) that are different from those of healthy people. The analysis methods for VOCs include chemical analysis and sensor array technology analysis. Chemical analysis includes gas chromatography-mass spectrometry (GC-MS): high sensitivity; low detection concentration; bulky; expensive; requires pre-concentration; cannot be analyzed in real time; requires professional operation. Proton transfer reaction-mass spectrometry (PTR-MS): no need for pre-concentration; simpler operation than GC-MS; substances with the same mass-to-charge ratio cannot be separated. Selected ion flow tube-mass spectrometry (SIFT-MS): real-time analysis; expensive; not suitable for clinical care. Ion mobility spectrometry (IMS): portable, cannot identify unknown components. Sensor array technology includes electronic nose: small size; cheap; simple to use; suitable for large-scale screening; cannot identify individual components, sensor drift; limited life; water vapor affects sensitivity. As can be seen from the above, the existing solutions cannot fully meet the detection needs in application scenarios such as the exhaled gas of lung cancer patients mentioned above. Summary of the invention

[0003] A main object of the present invention is to overcome at least one of the above-mentioned defects of the prior art and provide an electronic nose system with a selectable pre-concentration function.

[0004] Another main purpose of the present invention is to overcome at least one defect of the above-mentioned prior art and provide a gas detection method.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] According to one aspect of the present invention, an electronic nose system is provided. The electronic nose system comprises a sampling unit, a detection unit, a pre-concentration unit and a host computer control unit. The sampling unit comprises a sampling module, an air pump and a control panel, the sampling module is used to provide gas, the air pump is connected to the sampling module through a pipeline, and is configured to provide gas flow power. The detection unit comprises a sensor array detection module, the sensor array detection module is connected between the sampling module and the air pump through a pipeline, and is configured to detect the gas flowing through and convert the odor information of the gas into a digital signal. The pre-concentration unit is connected between the sampling module and the sensor array detection module through a pipeline, and is configured to perform pre-concentration treatment on the gas flowing through. The host computer control unit is connected to the control panel and the detection unit, and the host computer control unit is configured to receive the digital signal to output the qualitative analysis result or quantitative analysis result of the gas. Among them, the electronic nose system is configured to use the host computer control unit to control each valve group on the pipeline, so that the pre-concentration unit is selectively connected to the gas path between the injection module and the sensor array detection module to provide a pre-concentration function during the detection process.

[0007] According to one embodiment of the present invention, the injection module is connected to the input channel of the second three-way valve, one output channel of the second three-way valve is connected to the air inlet of the pre-concentration unit, another output channel of the second three-way valve is connected to an input channel of the third three-way valve, another input channel of the third three-way valve is connected to the air outlet of the pre-concentration unit, the output channel of the third three-way valve is connected to the air inlet of the detection unit, and the air outlet of the detection unit is connected to the air pump. The second three-way valve and the third three-way valve are respectively connected to the control panel.

[0008] According to one embodiment of the present invention, the sampling module comprises a sample container. The sample container is used to contain the gas sample to be detected, and the sample container is connected to an input channel of the first three-way valve. The other input channel of the first three-way valve is connected to the background air, the output channel of the first three-way valve is connected to the input channel of the second three-way valve, and the first three-way valve is connected to the control panel.

[0009] According to one embodiment of the present invention, a filter is provided on the pipeline connecting the first three-way valve to the background air.

[0010] According to one embodiment of the present invention, the injection module further comprises a carrier gas source. The carrier gas source is used to contain carrier gas, and the carrier gas source is connected to an input channel of the fifth three-way valve. Another input channel of the fifth three-way valve is connected to background air, an output channel of the fifth three-way valve is connected to another input channel of the first three-way valve, and the fifth three-way valve is connected to the control panel.

[0011] According to one embodiment of the present invention, an output channel of the second three-way valve is connected to a first port of a two-position five-way valve, a second port of the two-position five-way valve is connected to an air inlet end of the pre-concentration unit, a third port of the two-position five-way valve is connected to an input channel of a fourth three-way valve, a fourth port of the two-position five-way valve is connected to an air outlet end of the pre-concentration unit, a fifth port of the two-position five-way valve is connected to another input channel of the fourth three-way valve, an output channel of the fourth three-way valve is connected to another input channel of the fourth three-way valve, and the fourth three-way valve and the two-position five-way valve are respectively connected to the control panel.

[0012] According to one embodiment of the present invention, the injection unit further comprises a mass flow controller. The mass flow controller is arranged between the detection unit and the air pump, the air inlet end of the mass flow controller is connected to the air outlet end of the detection unit, the air outlet end of the mass flow controller is connected to the air pump, and the mass flow controller is connected to the host computer control unit. The mass flow controller is configured to be controlled by the host computer control unit to adjust the flow rate of the gas flowing through.

[0013] According to one embodiment of the present invention, the pre-concentration unit comprises a heating furnace, a heating tube, an adsorption tube and a temperature controller. The heating tube is arranged in a furnace cavity of the heating furnace. The adsorption tube is arranged on the heating tube. The temperature controller is connected to the heating tube and the adsorption tube, and is configured to collect temperature information of the adsorption tube, and thereby control the heating state of the heating tube.

[0014] According to one embodiment of the present invention, the sensor array detection module includes a metal oxide sensor array and an electrochemical sensor array, and the detection unit further includes a first air chamber and a second air chamber, wherein the first air chamber is configured to accommodate the metal oxide sensor array. The second air chamber is configured to accommodate the electrochemical sensor array. The first air chamber is located upstream of the second air chamber in the gas flow direction.

[0015] According to one embodiment of the present invention, the detection unit further comprises a single chip microcomputer which is connected to the digital signal sensors in the metal oxide sensor array and the electrochemical sensor array, and is connected to the host computer control unit.

[0016] According to one embodiment of the present invention, the detection unit further comprises a signal conditioning circuit and a data acquisition card. The signal conditioning circuit is connected to the analog output sensors in the metal oxide sensor array and the electrochemical sensor array. The data acquisition card is connected to the signal conditioning circuit and to the host computer control unit.

[0017] According to another aspect of the present invention, a gas detection method is provided, wherein the gas detection method comprises the following steps:

[0018] Provide an electronic nose system proposed by the present invention and described in the above embodiments;

[0019] Determine whether the concentration of the gas to be detected needs to be pre-concentrated;

[0020] When the gas to be detected needs to be pre-concentrated, the host computer control unit is used to control the valve groups on the pipeline so that the pre-concentration unit is connected to the gas path between the sampling module and the sensor array detection module, and then the gas is detected;

[0021] When the gas to be detected does not need to be pre-concentrated, the host computer control unit controls the valve groups on the pipeline so that the gas path between the sampling module and the sensor array detection module is directly connected across the pre-concentration module, and then the gas is detected.

[0022] It can be seen from the above technical solutions that the advantages and positive effects of the electronic nose system and gas detection method proposed in the present invention are:

[0023] The electronic nose system proposed by the present invention comprises a sampling unit, a detection unit, a pre-concentration unit and a host computer control unit. The sampling unit comprises a sampling module, an air pump and a control panel. The detection unit is connected between the sampling module and the air pump through a pipeline, and can detect the gas flowing through. The pre-concentration unit is connected between the sampling module and the sensor array detection module through a pipeline, and can perform pre-concentration treatment on the gas flowing through. The host computer control unit is connected to the control panel and the detection unit, and the host computer control unit can receive a digital signal to output the qualitative analysis result or quantitative analysis result of the gas. The electronic nose system can use the host computer control unit to control each valve group on the pipeline, so that the pre-concentration unit selectively accesses the gas path between the sampling module and the sensor array detection module to provide a pre-concentration function during the detection process. Through the above design, the electronic nose system proposed by the present invention combines the electronic nose technology with the pre-concentration technology. When the concentration of the detection substance is low, the host computer control unit can make the detection substance pass through the pre-concentration unit to increase the concentration of the detection substance. When the concentration of the detection substance is high, the host computer control unit can make the detection substance not pass through the pre-concentration unit. In addition, the electronic nose system has the advantages of good controllability, low cost, and high enrichment and concentration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various objects, features and advantages of the present invention will become more apparent by considering the following detailed description of preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are merely exemplary illustrations of the present invention and are not necessarily drawn to scale. In the accompanying drawings, the same reference numerals always refer to the same or similar parts. Among them:

[0025] Figure 1 is a functional block diagram of an electronic nose system according to an exemplary embodiment;

[0026] Figure 2 yes Figure 1 A partial structural schematic diagram of a pre-concentration unit of an electronic nose system is shown;

[0027] Figure 3 yes Figure 1 A schematic diagram of the structure of the first air chamber of the electronic nose system is shown;

[0028] Figure 4 yes Figure 1 A schematic diagram of the structure of the second air chamber of the electronic nose system is shown;

[0029] Figures 5 to 10 They are Figure 1 Schematic diagram of airflow path of the electronic nose system in various working stages;

[0030] Fig.11 for Figure 1The control flow chart of the electronic nose system shown when no pre-concentration is required;

[0031] Fig.12 for Figure 1 The control flow chart of the electronic nose system shown is when pre-concentration is required.

[0032] The following are the descriptions of the reference numerals:

[0033] 111. Sample container;

[0034] 112. Background air;

[0035] 113.Carrier gas source;

[0036] 114. Filter;

[0037] 120. Air pump;

[0038] 130. Control panel;

[0039] 140.Mass flow controller;

[0040] 210.Metal oxide sensor array;

[0041] 220. Electrochemical sensor array;

[0042] 230. First air chamber;

[0043] 240. Second air chamber;

[0044] 250. Single chip microcomputer;

[0045] 260.Signal conditioning circuit;

[0046] 270. Data acquisition card;

[0047] 300. Pre-concentration unit;

[0048] 310. Heating tube;

[0049] 320. Adsorption tube;

[0050] 410. Computer;

[0051] 420.USB hub;

[0052] T1. The first three-way valve;

[0053] T2. The second three-way valve;

[0054] T3. The third three-way valve;

[0055] T4. The fourth three-way valve;

[0056] T5. Two-position five-way valve;

[0057] T6. Fifth three-way valve. DETAILED DESCRIPTION

[0058] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and drawings therein are essentially for illustrative purposes rather than for limiting the present invention.

[0059] In the following description of different exemplary embodiments of the present invention, reference is made to the accompanying drawings, which form a part of the present invention and in which different exemplary structures, systems and steps that can implement multiple aspects of the present invention are shown by way of example. It should be understood that other specific schemes of components, structures, exemplary devices, systems and steps can be used, and structural and functional modifications can be made without departing from the scope of the present invention. Moreover, although the terms "above", "between", "within", etc. may be used in this specification to describe different exemplary features and elements of the present invention, these terms are used herein only for convenience, such as according to the direction of the examples described in the accompanying drawings. Nothing in this specification should be construed as requiring a specific three-dimensional orientation of the structure to fall within the scope of the present invention.

[0060] See also Figure 1 , which representatively shows the functional block diagram of the electronic nose system proposed in the present invention. In this exemplary embodiment, the electronic nose system proposed in the present invention is described by taking the application of detecting the exhaled gas of lung cancer patients as an example. It is easy for those skilled in the art to understand that in order to apply the relevant design of the present invention to the detection of other gases or other processes, various modifications, additions, substitutions, deletions or other changes are made to the specific embodiments described below, and these changes are still within the scope of the principle of the electronic nose system proposed in the present invention.

[0061] like Figure 1 As shown, in this embodiment, the electronic nose system proposed by the present invention mainly includes a sample injection unit, a detection unit, a pre-concentration unit and a host computer control unit. Figures 2 to 12 , Figure 2 A partial structural schematic diagram of a pre-concentration unit of an electronic nose system is representatively shown; Figure 3 A schematic diagram of the structure of the first air chamber of the electronic nose system is representatively shown; Figure 4 A schematic diagram of the structure of the second air chamber of the electronic nose system is representatively shown; Figures 5 to 10 The schematic diagrams of the airflow paths of the electronic nose system in various working stages are representatively shown respectively; Fig.11 The control flow chart of the electronic nose system when no pre-concentration is required is representatively shown; Fig.12The control flow chart of the electronic nose system when pre-concentration is required is representatively shown. The structure, connection mode and functional relationship of the main components of the electronic nose system proposed by the present invention are described in detail below in conjunction with the above-mentioned drawings.

[0062] like Figure 1 As shown, in this embodiment, the sampling unit mainly includes a sampling module, an air pump 120 and a control panel 130. The sampling module is used to provide gas for circulation in the electronic nose system, and the gas may include sample gas to be detected, background air 112 and carrier gas, etc. The air pump 120 is connected to the sampling module through a pipeline to provide flow power for the gas in the electronic nose system. The detection unit mainly includes a sensor array detection module, and the detection unit can convert the chemical signal of the gas itself into an electrical signal (digital signal) that is easy to process. The sensor array detection module is connected between the sampling module and the air pump 120 through a pipeline. The sensor array detection module can detect the gas flowing through and convert the odor information of the gas into a digital signal. The pre-concentration unit 300 is connected between the sampling module and the sensor array detection module through a pipeline, and the transport unit can perform pre-concentration treatment on the gas flowing through. The host computer control unit is connected to the control panel 130 and the detection unit. The host computer control unit can receive the digital signal sent by the sensor array detection module, and extract and analyze the data in the received digital signal, and output the qualitative analysis result or quantitative analysis result of the gas according to the digital signal. In addition, the host computer control unit is also connected to each valve group in the pipeline and the air pump 120. In the above, the electronic nose system can use the host computer control unit to control each valve group on each pipeline in the system, including controlling the opening and closing and the connection path of each valve group, so that the pre-concentration unit 300 can selectively access the gas path between the injection module and the sensor array detection module to provide a pre-concentration function when the gas needs to be pre-concentrated during the detection process. Through the above design, the electronic nose system proposed by the present invention combines the electronic nose technology with the pre-concentration technology. When the concentration of the detection substance is low, the host computer control unit can make the detection substance pass through the pre-concentration unit 300 to increase the concentration of the detection substance. When the concentration of the detection substance is high, the host computer control unit can be used to prevent the detection substance from passing through the pre-concentration unit 300. In addition, the electronic nose system has the advantages of good controllability, low cost, and high enrichment and concentration efficiency.

[0063] like Figure 1As shown, in this embodiment, the air circuit of the electronic nose system proposed by the present invention may preferably include five three-way valves and a two-position five-way valve T5, and the electronic nose system can use these valve groups to realize the function of the above-mentioned pre-concentration unit 300 selectively accessing and participating in the detection. Among them, for the convenience of understanding and explanation, in this embodiment, these three-way valves are defined as the first three-way valve T1, the second three-way valve T2, the third three-way valve T3, the fourth three-way valve T4 and the fifth three-way valve T6. Among them, each three-way valve has three channels, and the three channels of some three-way valves include one input channel and two output channels, and the three channels of another part of the three-way valves include two input channels and one output channel. The two-position five-way valve T5 includes five channel interfaces belonging to two phases respectively, and these five channel interfaces are defined as the first port, the second port, the third port, the fourth port and the fifth port. In addition, the above-mentioned three-way valves and the two-position five-way valve T5 are respectively connected to the control panel 130, and the upper computer control unit controls the five three-way valves and one two-position five-way valve T5 group respectively through the control panel 130, so that the pre-concentration unit 300 can be selectively connected to the gas path between the injection module and the sensor array detection module to selectively provide the corresponding pre-concentration function.

[0064] Preferably, if Figure 1 As shown, in this embodiment, the injection module is connected to the input channel of the second three-way valve T2, an output channel of the second three-way valve T2 is connected to the air inlet end of the pre-concentration unit 300 (i.e., the air inlet end of the adsorption tube 320), another output channel of the second three-way valve T2 is connected to an input channel of the third three-way valve T3, another input channel of the third three-way valve T3 is connected to the air outlet end of the pre-concentration unit 300 (i.e., the air outlet end of the adsorption tube 320), the output channel of the third three-way valve T3 is connected to the air inlet end of the detection unit, and the air outlet end of the detection unit is connected to the air pump 120.

[0065] Furthermore, if Figure 1 As shown, in this embodiment, the sampling module may preferably include a sample container 111, and the sample container 111 can contain a gas sample to be detected. Specifically, the sample container 111 is connected to an input channel of the first three-way valve T1, another input channel of the first three-way valve T1 is connected to the background air 112, and the output channel of the first three-way valve T1 is connected to the input channel of the second three-way valve T2.

[0066] Furthermore, if Figure 1 As shown, in this embodiment, a filter 114 may preferably be provided on the pipeline connecting the first three-way valve T1 to the background air 112 .

[0067] Furthermore, if Figure 1As shown, in this embodiment, the injection module may also preferably include a carrier gas source 113, and the carrier gas source 113 can contain carrier gas. Specifically, the carrier gas source 113 is connected to an input channel of the fifth three-way valve T6, another input channel of the fifth three-way valve T6 is connected to the background air 112, and the output channel of the fifth three-way valve T6 is connected to another input channel of the first three-way valve T1.

[0068] Furthermore, in this embodiment, the carrier gas contained in the carrier gas source 113 can preferably be high-purity helium. In other embodiments, according to different types of sample gases to be detected, the carrier gas can also be selected from hydrogen, nitrogen, argon or carbon dioxide, and the purity level of the carrier gas can also be flexibly selected according to needs.

[0069] Furthermore, if Figure 1 As shown, in this embodiment, an output channel of the second three-way valve T2 is connected to the first port of the two-position five-way valve T5, the second port of the two-position five-way valve T5 is connected to the air inlet end of the pre-concentration unit 300 (i.e., the air inlet end of the adsorption tube 320), the third port of the two-position five-way valve T5 is connected to an input channel of the fourth three-way valve T4, the fourth port of the two-position five-way valve T5 is connected to the air outlet end of the pre-concentration unit 300 (i.e., the air outlet end of the adsorption tube 320), the fifth port of the two-position five-way valve T5 is connected to another input channel of the fourth three-way valve T4, and the output channel of the fourth three-way valve T4 is connected to another input channel of the fourth three-way valve T4.

[0070] Preferably, in this embodiment, the air pump 120 may be a vacuum pump.

[0071] Preferably, in this embodiment, the control panel 130 may be an I / O control panel.

[0072] Preferably, if Figure 1 As shown, in this embodiment, the control panel 130 and the host computer control unit can be preferably connected via a USB cable. The host computer control unit includes a computer 410 and a USB hub 420, and the control panel 130 is connected to a USB interface of the USB hub 420 via a USB cable.

[0073] Preferably, if Figure 1As shown, in this embodiment, the sampling unit may also preferably include a mass flow controller 140. Specifically, the mass flow controller 140 is arranged between the detection unit and the air pump 120, the air inlet end of the mass flow controller 140 is connected to the air outlet end of the detection unit, the air outlet end of the mass flow controller 140 is connected to the air pump 120, and the mass flow controller 140 is connected to the host computer control unit. Accordingly, the mass flow controller 140 can be controlled by the host computer control unit to accurately adjust and control the flow of the gas flowing through the electronic nose system. And the host computer control unit completes the flow setting of the mass flow controller 140 and reads the real-time flow to ensure the stability of the flow in the corresponding gas path.

[0074] Furthermore, if Figure 1 As shown, in this embodiment, the mass flow controller 140 and the host computer control unit can be preferably connected via a USB cable. The host computer control unit includes a computer 410 and a USB hub 420, and the mass flow controller 140 is connected to a USB interface of the USB hub 420 via a USB cable.

[0075] Preferably, if Figure 1 and Figure 2 As shown, in this embodiment, the pre-concentration unit 300 mainly includes a heating furnace, a heating tube 310, an adsorption tube 320 and a temperature controller. Specifically, the heating tube 310 is arranged in the furnace cavity of the heating furnace. The adsorption tube 320 is arranged on the heating tube 310. The temperature controller is connected to the heating tube 310 and the adsorption tube 320. The temperature controller can collect temperature information of the adsorption tube 320 and control the heating state of the heating tube 310, thereby realizing temperature control of the adsorption tube 320 in the adsorption stage, the thermal desorption stage and the cleaning stage.

[0076] Furthermore, in this embodiment, the material of the heating furnace may preferably include aluminum alloy.

[0077] Furthermore, if Figure 2 As shown, in this embodiment, the pre-concentration unit 300 may preferably include four heating tubes 310, and the four heating tubes 310 are arranged parallel to each other. The four heating tubes 310 may preferably be stacked into two layers, the upper layer includes one heating tube 310, the lower layer includes three heating tubes 310, and the one heating tube 310 in the upper layer is located above the middle one of the three heating tubes 310 in the lower layer.

[0078] Furthermore, if Figure 2 As shown, in this embodiment, the four heating tubes 310 may preferably be an integrated structure.

[0079] Furthermore, if Figure 2As shown, in this embodiment, based on the structural design of stacking the four heating tubes 310 in two layers, the upper surfaces of the two heating tubes 310 on both sides of the lower layer respectively form step structures on both sides of the heating tube 310 on the upper layer. On this basis, the pre-concentration unit 300 may preferably include two adsorption tubes 320, and the two adsorption tubes 320 are respectively arranged on the two of the three heating tubes 310 on both sides of the lower layer, that is, the two adsorption tubes 320 are respectively arranged on the two step structures.

[0080] Further, in this embodiment, the heating tube 310 may preferably be an infrared carbon fiber heating tube 310 .

[0081] Further, in this embodiment, the adsorption tube 320 may preferably be a Tenax-TA adsorption tube 320 .

[0082] Furthermore, in this embodiment, the adsorbent in the adsorption tube 320 can be preferably a porous water-permeable polymer. Since the porous water-permeable polymer is inert, it is suitable for detecting active gases such as mercaptan, pinene, tear gas, etc. At the same time, since the porous water-permeable polymer is hydrophobic, it is suitable for detection in a humid environment and can detect substances of C6 to C30.

[0083] Further, in this embodiment, the temperature controller may preferably be a PID temperature controller.

[0084] Furthermore, in this embodiment, the temperature controller can be preferably connected to the heating tube 310 and the adsorption tube 320 via an RS485 communication link. Accordingly, the temperature information of the adsorption tube 320 is converted into an electrical signal via a thermocouple and then transmitted to the temperature controller via an RS485 communication link, and the control signal of the temperature controller is transmitted to the heating tube 310 via the RS485 communication link.

[0085] Furthermore, in this embodiment, the pre-concentration unit 300 may also preferably include an aerogel insulation layer. Specifically, the aerogel insulation layer may be provided in the pre-concentration unit 300, for example, on a heating furnace, and the aerogel insulation layer can provide heat insulation for the heating structure of the pre-concentration unit 300 during heating.

[0086] Furthermore, in this embodiment, the pre-concentration unit 300 may also preferably include an air cooling module. Specifically, the air cooling module may be disposed in the pre-concentration unit 300, for example, disposed on both sides of the heating furnace, and the air cooling module may provide a cooling function for the heating structure of the pre-concentration unit 300 in the non-high temperature stage.

[0087] Preferably, if Figure 1 , Figure 3 and Figure 4As shown, in this embodiment, the sensor array detection module may preferably include a metal oxide sensor array 210 and an electrochemical sensor array 220. On this basis, the detection unit may also preferably include a first gas chamber 230 and a second gas chamber 240. The first gas chamber 230 is used to accommodate the metal oxide sensor array 210, and the second gas chamber 240 is used to accommodate the electrochemical sensor array 220. In addition, the gas flowing through the sensor array detection module may preferably flow through the metal oxide sensor array 210 first, and then flow through the electrochemical sensor array 220, that is, the first gas chamber 230 is located upstream of the second gas chamber 240 in the gas flow direction.

[0088] It should be noted that Figure 3 The first air chamber 230 shown in the figure omits the structure of the first cover plate, which can seal the first air chamber 230. Further, each sensor of the metal oxide sensor array 210 accommodated in the first air chamber 230 can be preferably arranged on the first cover plate, and these sensors can be integrated into a circuit board in an integrated manner, and the circuit board is arranged on the first cover plate.

[0089] It should be noted that Figure 4 The second air chamber 240 shown in the figure omits the structure of the second cover plate, which can seal the second air chamber 240. Further, each sensor of the electrochemical sensor array 220 accommodated in the second air chamber 240 can be preferably arranged on the second cover plate, and these sensors can be integrated into a circuit board in an integrated manner, and the circuit board is arranged on the second cover plate.

[0090] Furthermore, in this embodiment, the metal oxide sensor array 210 may preferably include a metal oxide sensor and a digital temperature and humidity sensor.

[0091] Further, in this embodiment, the electrochemical sensor array 220 may preferably include an electrochemical sensor, a photoionization gas sensor, a hot wire gas sensor, a MEMS gas sensor, a solid electrolyte gas sensor, and a digital temperature and humidity sensor.

[0092] Furthermore, in this embodiment, a heating plate may be preferably provided at the bottom of the first air chamber 230, and the first air chamber 230 can use the heating plate to heat the metal oxide sensors and other sensors in the metal oxide sensor array 210 to ensure that the metal oxide sensors and other sensors can operate in a better temperature environment.

[0093] Furthermore, in this embodiment, the heating plate can preferably be a 70° C. constant temperature silicone heating plate to ensure that sensors such as metal oxide sensors can operate in an optimal temperature environment.

[0094] Furthermore, if Figure 1 As shown, in this embodiment, the detection unit may also preferably include a single chip microcomputer 250. Specifically, the single chip microcomputer 250 is connected to each digital signal type sensor in the metal oxide sensor array 210 and the electrochemical sensor array 220, and the single chip microcomputer 250 is also connected to the host computer control unit. Therefore, the digital signal type sensor can transmit the digital signal to the host computer control unit via the single chip microcomputer 250.

[0095] Furthermore, in this embodiment, each digital signal type sensor in the metal oxide sensor array 210 and the electrochemical sensor array 220 can preferably be connected via I 2 The C interface is connected to the single chip microcomputer 250 .

[0096] Furthermore, in this embodiment, the single-chip microcomputer 250 and the host computer control unit can be preferably connected via a USB cable. The host computer control unit includes a computer 410 and a USB hub 420, and the single-chip microcomputer 250 is connected to a USB interface of the USB hub 420 via a USB cable.

[0097] Furthermore, if Figure 1 As shown, in this embodiment, the detection unit may also preferably include a signal conditioning circuit 260 and a data acquisition card 270. Specifically, the signal conditioning circuit 260 is connected to each analog output sensor in the metal oxide sensor array 210 and the electrochemical sensor array 220. The data acquisition card 270 is connected to the signal conditioning circuit 260, and the data acquisition card 270 is also connected to the host computer control unit. Accordingly, the analog signal measured by the analog output sensor passes through the signal conditioning circuit 260, enters the data acquisition card 270, is converted into a digital signal, and then transmitted to the host computer control unit.

[0098] Furthermore, in this embodiment, the data acquisition card 270 and the host computer control unit can be preferably connected via a USB cable. The host computer control unit includes a computer 410 and a USB hub 420, and the data acquisition card 270 is connected to a USB interface of the USB hub 420 via a USB cable.

[0099] Based on the above detailed exemplary description of a preferred embodiment of the electronic nose system proposed by the present invention, Figures 5 to 12 , the two main working modes of the electronic nose system proposed in the present invention are explained.

[0100] The detection control method without the participation of the pre-concentration unit 300 comprises the following steps:

[0101] S11: The host computer control unit sets the first three-way valve T1, the second three-way valve T2, the third three-way valve T3, the fifth three-way valve T6, and the mass flow controller 140, and turns on the vacuum pump to make the electronic nose system enter the baseline collection stage. The airflow channel in the baseline collection stage can be seen in Figure 5 As shown;

[0102] S12: The host computer control unit updates the first three-way valve T1 and the mass flow controller 140, so that the system enters the injection stage. The air flow channel in the injection stage can be seen in Figure 6 As shown;

[0103] S13: The host computer control unit updates the first three-way valve T1 and the mass flow controller 140, so that the system enters the sensor array cleaning stage. The air flow channel in the sensor array cleaning stage can be referred to again. Figure 5 As shown;

[0104] At this point, the electronic nose system has roughly completed a detection control process without the participation of the pre-concentration unit 300. The overall detection control process can be seen in Fig.11 shown.

[0105] The detection control method with the participation of the pre-concentration unit 300 comprises the following steps:

[0106] S21: The host computer control unit sets the first three-way valve T1, the second three-way valve T2, the third three-way valve T3, the fourth three-way valve T4, the fifth three-way valve T6, the two-position five-way valve T5, and the mass flow controller 140, and turns on the vacuum pump to make the system enter the air baseline collection stage. The air flow channel in the air baseline collection stage can be seen in Figure 7 As shown;

[0107] S22: The host computer control unit updates the fifth three-way valve T6 and the mass flow controller 140, so that the system enters the helium (carrier gas) baseline acquisition stage. The gas flow channel in the helium baseline acquisition stage can be seen in Figure 8 As shown;

[0108] S23: The host computer control unit updates the first three-way valve T1 and the mass flow controller 140, so that the system enters the adsorption stage. The air flow channel in the adsorption stage can be seen in Fig. 9 As shown;

[0109] S24: The host computer control unit updates the first three-way valve T1, the fifth three-way valve T6, and the mass flow controller 140, so that the system enters the post-sampling stage. The air flow channel in the post-sampling stage can be referred to again. Figure 7 As shown;

[0110] S25: The host computer control unit updates the second three-way valve T2, the third three-way valve T3, and the mass flow controller 140, turns off the vacuum pump, and causes the system to enter a thermal desorption stage, in which there is no airflow in the airflow channel;

[0111] S26: The host computer control unit sets the second three-way valve T2, the third three-way valve T3, the fourth three-way valve T4, the fifth three-way valve T6, the two-position five-way valve T5, and the mass flow controller 140, and turns on the vacuum pump to make the system enter the injection stage. The air flow channel in the injection stage can be seen in Fig.10 As shown;

[0112] S27: The host computer control unit updates the mass flow controller 140, so that the system enters the cleaning thermal desorption stage. The air flow channel in the thermal desorption stage can be referred to again. Fig.10 As shown;

[0113] S28: The host computer control unit updates the second three-way valve T2, the third three-way valve T3, the fifth three-way valve T6, and the mass flow controller 140, so that the system enters the sensor array cleaning stage. The air flow channel in the sensor array cleaning stage can be referred to again. Figure 5 As shown;

[0114] At this point, the electronic nose system has roughly completed a detection control process involving the pre-concentration unit 300. The overall detection control process can be seen in Fig.12 shown.

[0115] It should be noted that the electronic nose systems shown in the drawings and described in this specification are only a few examples of the many electronic nose systems that can employ the principles of the present invention. It should be clearly understood that the principles of the present invention are by no means limited to any details of the electronic nose systems shown in the drawings or described in this specification or any components of the electronic nose systems.

[0116] Based on the above specific description of the preferred implementation of the electronic nose system proposed in the present invention, the gas detection method proposed in the present invention will be described below.

[0117] In this embodiment, the gas detection method proposed by the present invention comprises at least the following steps:

[0118] Provide an electronic nose system proposed by the present invention and specifically described in the above embodiments;

[0119] Determine whether the concentration of the gas to be detected needs to be pre-concentrated;

[0120] When the gas to be detected needs to be pre-concentrated, the host computer control unit controls the valve groups on the pipeline so that the pre-concentration unit is connected to the gas path between the sampling module and the sensor array detection module, and then the gas is detected;

[0121] When the gas to be detected does not need to be pre-concentrated, the host computer control unit controls the valve groups on the pipeline so that the gas path between the sampling module and the sensor array detection module is directly connected across the pre-concentration module, and then the gas is detected.

[0122] It should be noted that the gas detection method packages shown in the drawings and described in this specification are only a few examples of the many ways in which the principles of the present invention can be employed. It should be clearly understood that the principles of the present invention are by no means limited to any details or any steps of the gas detection method packages shown in the drawings or described in this specification.

[0123] In summary, the electronic nose system proposed in the present invention comprises a sampling unit, a detection unit, a pre-concentration unit and a host computer control unit. The sampling unit comprises a sampling module, an air pump and a control panel. The detection unit is connected between the sampling module and the air pump through a pipeline, and can detect the gas flowing through. The pre-concentration unit is connected between the sampling module and the sensor array detection module through a pipeline, and can perform pre-concentration treatment on the gas flowing through. The host computer control unit is connected to the control panel and the detection unit, and the host computer control unit can receive a digital signal to output the qualitative analysis result or quantitative analysis result of the gas. The electronic nose system can use the host computer control unit to control each valve group on the pipeline, so that the pre-concentration unit selectively accesses the gas path between the sampling module and the sensor array detection module to provide a pre-concentration function during the detection process. Through the above design, the electronic nose system proposed in the present invention combines the electronic nose technology with the pre-concentration technology. When the concentration of the detection substance is low, the host computer control unit can make the detection substance pass through the pre-concentration unit to increase the concentration of the detection substance. When the concentration of the detection substance is high, the host computer control unit can make the detection substance not pass through the pre-concentration unit. In addition, the electronic nose system has the advantages of good controllability, low cost, and high enrichment and concentration efficiency.

[0124] The exemplary embodiments of the electronic nose system and gas detection method proposed by the present invention are described and / or illustrated in detail above. However, the embodiments of the present invention are not limited to the specific embodiments described herein. On the contrary, the components and / or steps of each embodiment can be used independently and separately from other components and / or steps described herein. Each component and / or each step of an embodiment can also be used in combination with other components and / or steps of other embodiments. When introducing the elements / components / etc. described and / or illustrated herein, the terms "one", "one" and "above" are used to indicate the presence of one or more elements / components / etc. The terms "comprising", "including" and "having" are used to indicate the meaning of open inclusion and mean that in addition to the listed elements / components / etc., there may be other elements / components / etc. In addition, the terms "first" and "second" in the claims and the specification are used only as marks and are not numerical restrictions on their objects.

[0125] Although the electronic nose system and gas detection method of the present invention have been described according to different specific embodiments, those skilled in the art will recognize that the implementation of the present invention can be modified within the spirit and scope of the claims.

Claims

1. An electronic nose system, characterized in that: The electronic nose system comprises: The sampling unit comprises a sampling module, an air pump and a control panel, wherein the sampling module is used to provide gas, and the air pump is connected to the sampling module through a pipeline and is configured to provide gas flow power; A detection unit, comprising a sensor array detection module, the sensor array detection module is connected between the sampling module and the air pump through a pipeline, and is configured to detect the gas flowing through and convert the odor information of the gas into a digital signal, the sensor array detection module comprises a metal oxide sensor array and an electrochemical sensor array; A pre-concentration unit, connected between the sampling module and the sensor array detection module through a pipeline, and configured to perform pre-concentration processing on the gas flowing through; as well as A host computer control unit connected to the control panel and the detection unit, wherein the host computer control unit is configured to receive the digital signal and output a qualitative analysis result or a quantitative analysis result of the gas; The electronic nose system is configured to utilize the host computer control unit to control each valve group on the pipeline, so that the pre-concentration unit is selectively connected to the gas path between the injection module and the sensor array detection module to provide a pre-concentration function during the detection process; The detection unit further comprises a first air chamber and a second air chamber; the first air chamber is configured to accommodate the metal oxide sensor array, and the second air chamber is configured to accommodate the electrochemical sensor array; the first air chamber is located upstream of the second air chamber in the gas flow direction; a heating plate is provided at the bottom of the first air chamber, and the first air chamber can use the heating plate to heat the metal oxide sensor; Wherein, the detection unit also includes a single-chip microcomputer, a signal conditioning circuit and a data acquisition card; the single-chip microcomputer is connected to the digital signal sensors in the metal oxide sensor array and the electrochemical sensor array, and the single-chip microcomputer is connected to the host computer control unit; the signal conditioning circuit is connected to the analog output sensors in the metal oxide sensor array and the electrochemical sensor array; the data acquisition card is connected to the signal conditioning circuit and to the host computer control unit.

2. The electronic nose system according to claim 1, characterized in that: The injection module is connected to the input channel of the second three-way valve, an output channel of the second three-way valve is connected to the air inlet end of the pre-concentration unit, another output channel of the second three-way valve is connected to an input channel of the third three-way valve, another input channel of the third three-way valve is connected to the air outlet end of the pre-concentration unit, the output channel of the third three-way valve is connected to the air inlet end of the detection unit, and the air outlet end of the detection unit is connected to the air pump; wherein the second three-way valve and the third three-way valve are respectively connected to the control panel.

3. The electronic nose system according to claim 2, characterized in that: The injection module comprises: A sample container, used to contain a gas sample to be detected, wherein the sample container is connected to an input channel of the first three-way valve; Wherein, another input channel of the first three-way valve is connected to background air, the output channel of the first three-way valve is connected to the input channel of the second three-way valve, and the first three-way valve is connected to the control panel.

4. The electronic nose system according to claim 3, characterized in that: A filter is provided on the pipeline connecting the first three-way valve to the background air.

5. The electronic nose system according to claim 3, characterized in that: The injection module also comprises: A carrier gas source, used to contain a carrier gas, wherein the carrier gas source is connected to an input channel of the fifth three-way valve; Wherein, another input channel of the fifth three-way valve is connected to the background air, the output channel of the fifth three-way valve is connected to another input channel of the first three-way valve, and the fifth three-way valve is connected to the control panel.

6. The electronic nose system according to claim 2, characterized in that: An output channel of the second three-way valve is connected to a first port of a two-position five-way valve, a second port of the two-position five-way valve is connected to an air inlet end of the pre-concentration unit, a third port of the two-position five-way valve is connected to an input channel of a fourth three-way valve, a fourth port of the two-position five-way valve is connected to an air outlet end of the pre-concentration unit, a fifth port of the two-position five-way valve is connected to another input channel of the fourth three-way valve, an output channel of the fourth three-way valve is connected to another input channel of the fourth three-way valve, and the fourth three-way valve and the two-position five-way valve are respectively connected to the control panel.

7. The electronic nose system according to claim 1, characterized in that: The injection unit also comprises: A mass flow controller is provided between the detection unit and the air pump, the air inlet end of the mass flow controller is connected to the air outlet end of the detection unit, the air outlet end of the mass flow controller is connected to the air pump, and the mass flow controller is connected to the host computer control unit; Wherein, the mass flow controller is configured to be controlled by the host computer control unit to adjust the flow rate of the gas flowing through.

8. The electronic nose system according to claim 1, characterized in that: The pre-concentration unit comprises: Heating furnace; A heating tube is arranged in the furnace chamber of the heating furnace; an adsorption tube, disposed on the heating tube; and The temperature controller is connected to the heating tube and the adsorption tube, and is configured to collect temperature information of the adsorption tube and control the heating state of the heating tube accordingly.

9. A gas detection method, characterized in that: The following steps are involved: Providing an electronic nose system according to any one of claims 1 to 8; Determine whether the concentration of the gas to be detected needs to be pre-concentrated; When the gas to be detected needs to be pre-concentrated, the host computer control unit is used to control the valve groups on the pipeline so that the pre-concentration unit is connected to the gas path between the sampling module and the sensor array detection module, and then the gas is detected; When the gas to be detected does not need to be pre-concentrated, the host computer control unit is used to control the valve groups on the pipeline so that the gas path between the sampling module and the sensor array detection module is directly connected across the pre-concentration unit, and then the gas is detected.

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