JP2009058398A - Gas concentration detector - Google Patents

Abstract

It is possible to detect the concentration of a gas to be detected in exhaled air with high sensitivity and high accuracy by simply breathing naturally without inhaling exhaled air.
An exhalation determining unit determines whether or not exhaled air is contained in the air in an exhalation introducing tube based on an output concentration from an oxygen sensor. When the exhalation start signal is input from the exhalation determination unit, the first valve is switched to open the gas flow path to the first collection pipe, and the ethanol gas component in the exhalation air in the exhalation introduction pipe is first collected. Collect by suction in a collecting tube. Also, when the expiration end signal is input from the expiration determination unit, the second valve is switched to open the gas flow path to the second collection pipe, and the ethanol gas component in the vehicle interior air in the expiration introduction pipe is removed. Then, suction is collected in the second collection tube. Then, the ethanol gas components collected in each of the first collection tube and the second collection tube are heated and desorbed, and the ethanol gas concentration is detected by the alcohol sensor.
[Selection] Figure 4

Description

  The present invention relates to a gas concentration detection device, and more particularly to a gas concentration detection device capable of detecting the concentration of alcohol contained in a driver's breath.

  Conventionally, many alcohol concentration detecting devices in the driver's breath for preventing drunk driving have been proposed. For example, there is known an interlock system (made by Dräger) that prevents the engine from starting when the driver blows in the breath, detects the alcohol concentration in the breath, and alcohol above a certain concentration is detected. In this system, since only exhalation is introduced into the detector, exhalation is not diluted, and alcohol in the exhalation can be detected without being affected by the air component in the passenger compartment.

  Also, a drunk driving prevention device that detects the alcohol concentration in the breath corresponding to the driver's blowing operation is known to prevent unauthorized operation (Patent Document 1). In this device, in addition to the alcohol sensor, any one or more of a temperature sensor, a humidity sensor, a pressure sensor, and a flow rate sensor are built in, and reacts only to the driver's breath blowing operation to detect the alcohol concentration in the breath. This prevents illegal driving (drinking driving) due to unauthorized operation.

  Further, an exhaled gas concentration collection device including an exhalation collection container, a collection tube and a suction pump communicating with the exhalation collection container is known (Patent Document 2). The purpose of this apparatus is to shorten the working time, simplify the work, and prevent contamination of the collecting pipe by the automatic attachment / detachment mechanism of the collecting pipe joint.

In addition, when analyzing a dilute component in a gas, there is a method for concentration and collection using a collection tube filled with an adsorbent according to the target component, and then desorbing and introducing it into a gas analyzer. Are known.
JP-A-2005-96663 JP-A-10-108850

  However, the above-described interlock system has a problem that it is troublesome for the driver because the driver must inhale.

  In addition, the technique described in Patent Document 1 has a problem that, when detecting a dilute component in exhaled breath blown to a detector, the sensitivity may be insufficient and the component may not be detected as it is.

  Further, in the technique described in Patent Document 2, when the passenger compartment air is simply sucked into the collection tube and collected and detected, the target driver's breath component and other passenger compartment components (for example, passengers) , Components that volatilized from vehicle interior materials, drivers or passengers' perfume and cosmetics, fragrance components in the passenger compartment, etc.) There is a problem that can not be.

  The present invention has been made to solve the above-described problems, and can detect the concentration of a detection target gas in exhalation with high sensitivity and high accuracy by simply breathing naturally without inhaling exhalation. An object is to provide a gas concentration detection device.

  In order to achieve the above object, the gas concentration detection device of the present invention determines that exhaled gas is included in the gas to be detected, and whether or not exhaled gas is included in the detection target gas. A suction collecting means for sucking the detection target gas and collecting the detection target gas component, and discharging the detection target gas component collected by the suction collection means, Detection target gas concentration detection means for detecting the concentration; and calculation means for calculating the concentration of the detection target gas in the expiration based on the concentration of the detection target gas detected by the detection target gas concentration detection means It consists of

  According to the gas concentration detection apparatus of the present invention, it is determined whether or not expiration gas is included in the gas to be detected by the expiration determination unit, and it is determined by the aspiration collection unit that expiration is included by the expiration determination unit. The gas to be detected is sucked to collect the gas component to be detected.

  Then, the detection target gas concentration detection means releases the detection target gas component collected by the suction collection means, detects the concentration of the detection target gas, and the calculation means detects the detection target gas concentration detection means. Based on the concentration of the detection target gas, the concentration of the detection target gas in the expiration is calculated.

  In this way, when exhalation is contained in the detection target gas, the detection target gas component is distinguished by sucking the detection target gas and collecting the detection target gas component. Since the concentration of the gas to be detected can be collected and detected, the concentration of the gas to be detected in exhaled breath can be detected with high sensitivity and high accuracy simply by breathing naturally without inhaling the breath. it can.

  The gas concentration detection apparatus according to the present invention further includes reference gas concentration detection means for detecting the concentration of the reference gas contained in the gas to be detected, and the expiration determination means is the reference gas detected by the reference gas concentration detection means. Whether or not exhaled gas is contained in the gas to be detected can be determined based on the concentration of. Thereby, it is possible to accurately determine whether or not exhalation is included based on the concentration of the reference gas contained in the gas to be detected.

  In the gas concentration detection apparatus including the reference gas concentration detection unit, the calculation unit determines the concentration of the detection target gas detected by the detection target gas concentration detection unit and the concentration of the reference gas detected by the reference gas concentration detection unit. Based on this, the concentration of the detection target gas in exhaled breath can be calculated.

  The suction collection means according to the present invention includes a plurality of collection units for collecting the detection target gas component, and switches to any of the plurality of collection units according to the determination result by the expiration determination unit, and the detection target The detection target gas component is collected in the switched collection unit by sucking the gas, and the detection target gas concentration detection means releases the detection target gas component collected in each of the plurality of collection units. Each of the detection target gas concentrations is detected, and the calculation means discharges the detection target gas components of the plurality of collection units by the detection target gas concentration detection means, based on the respective detection target gas concentrations detected. The concentration of the detection target gas during expiration can be calculated. As a result, according to the determination result of whether or not exhalation is included in the gas to be detected, the gas to be included in exhalation and exhalation are included by switching the collection unit and collecting the detection target gas component. The concentration of the detection target gas can be detected for each of the gases that are not present.

  In the gas concentration detection apparatus including the collection unit, the detection target gas concentration detection unit releases the detection target gas component collected in the collection unit by suction for a predetermined suction time, and determines the concentration of the detection target gas. Can be detected. Accordingly, since the suction is performed for a predetermined suction time, the concentration of the detection target gas can be detected with a desired sensitivity.

  In the gas concentration detection apparatus including the collection unit, the suction collection unit is switched to one of a plurality of collection units according to a determination result by the expiration determination unit, and a plurality of suction collection units are provided for each suction of a predetermined suction time. The detection target gas component is collected in the collection unit that is switched by sucking the gas to be detected and switched, and the detection target gas concentration detection means is connected to the collection unit. Each time a component is collected, the concentration of the detection target gas can be detected by releasing the detection target gas component collected by the collection unit. Thereby, the concentration of the detection target gas can be adjusted with a desired time resolution by switching the collection unit for each suction of a predetermined suction time, collecting the detection target gas component, and detecting the concentration of the detection target gas. Can be detected.

  In the gas concentration detection apparatus including the collection unit, the suction collection unit switches the valve so as to open a gas flow path to any of the plurality of collection units according to the determination result by the expiration determination unit. The gas component to be detected can be collected in the collecting unit switched by sucking the gas to be detected by operating the pump.

  The gas concentration detection apparatus including the collection unit further includes reference gas concentration detection means for detecting the concentration of the reference gas contained in the detection target gas, and the calculation means includes a plurality of detection target gas concentration detection means. The concentration of the detection target gas detected by releasing each detection target gas component of the collection unit, and the reference gas detected by the reference gas concentration detection means when the expiration determination means determines that exhalation is included. Based on the concentration, the concentration of the reference gas detected by the reference gas concentration detecting means when the expiration determining means determines that exhalation is not included, and the concentration of the reference gas in the expiration determined in advance, The concentration of the detection target gas can be calculated.

  The calculating means includes the reference gas concentration detected by the reference gas concentration detecting means when the expiration determining means determines that exhalation is included, and the reference gas when the expiration determining means determines that exhalation is not included. Based on the concentration of the reference gas detected by the concentration detection means and the concentration of the reference gas in the expiration determined in advance, the expiration dilution rate is calculated, and the calculated expiration dilution rate and the detection target gas concentration detection means The concentration of the detection target gas in the expiration can be calculated based on the concentration of the detection target gas detected by releasing the detection target gas component of each of the plurality of collection units.

  The detection target gas may be ethanol gas, and the reference gas may be any one of oxygen, carbon dioxide, and water vapor.

  The above-mentioned reference gas concentration detection means is an absorption spectrum generated by interaction with infrared rays emitted from a human face and transmits infrared rays having a predetermined wavelength band including an absorption spectrum caused by CO stretching vibration of carbon dioxide. Carbon dioxide detection means including an optical filter for carbon and carbon dioxide conversion means for converting infrared light transmitted through the optical filter for carbon dioxide into an electrical signal, an absorption spectrum generated by the interaction of infrared light emitted from a human face A water vapor detection means comprising: an optical filter for water vapor that transmits infrared rays in a predetermined wavelength band including an absorption spectrum by water vapor; and a water vapor conversion means that converts the infrared light transmitted through the optical filter for water vapor into an electrical signal, A gas that detects the concentration of a reference gas composed of at least one of carbon dioxide and oxygen. Sensor can be constituted by carbon dioxide sensor is composed of a light source and an infrared detector that emits configured steam sensor or infrared, with a light source and an infrared detector that emits infrared.

  As a gas sensor for detecting the concentration of the reference gas, a water vapor sensor for detecting the concentration of water vapor using an oxide semiconductor or polymer film capacitance, a carbon dioxide sensor for detecting the concentration of carbon dioxide using a solid electrolyte, or An oxygen sensor that detects the oxygen concentration using a solid electrolyte can be used.

  The detection target gas concentration detection means transmits an infrared spectrum having a predetermined wavelength band including an absorption spectrum generated by an interaction with infrared rays emitted from a human face and including an absorption spectrum caused by CO stretching vibration of ethanol. An ethanol detector including an ethanol optical filter, and an ethanol conversion means for converting infrared light transmitted through the ethanol optical filter into an electrical signal, a gas sensor for detecting the concentration of ethanol gas using an oxide semiconductor, or infrared light It can comprise with the alcohol sensor comprised by the light source and infrared detector which radiate | emit.

  As described above, according to the present invention, when exhalation is included in the gas to be detected, the gas to be detected is sucked to collect the detection target gas component, whereby the gas in the gas containing exhalation is collected. Since the detection target gas components can be distinguished and collected, and the concentration of the detection target gas can be detected, the concentration of the detection target gas in the exhaled breath can be detected with high sensitivity only by breathing naturally without bothering the exhalation. The effect that it can detect with high precision is acquired.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case where the present invention is applied to an ethanol concentration detection device that detects the concentration of ethanol, which is a kind of alcohol, from the breath of a driver will be described as an example.

  As shown in FIG. 1, the ethanol concentration detection apparatus 10 according to the first embodiment is attached to a steering column 12 provided in a driver's seat at a position where a driver's breath can reach.

  As shown in FIG. 2, the ethanol concentration detection apparatus 10 includes an elongate cylindrical exhalation introduction tube 20 having a suction port 20 </ b> A whose diameter is increased at the distal end, and the aspiration concentration described later by the exhalation introduction tube 20. Air sucked from the suction port 20 </ b> A is sent to the portion 22. An oxygen sensor 24 that detects the concentration of oxygen is attached to the inside of the exhalation introduction tube 20.

  The oxygen sensor 24 is a sensor that detects the concentration of oxygen in the air flowing in the exhalation-introducing pipe 20, and for example, FCX-MVL (trade name, manufactured by Fujikura) using a zirconia solid electrolyte can be used. .

  Further, the ethanol concentration detection device 10 includes an elongated cylindrical clean air introduction pipe 26 having a gas filter 26A for generating clean air formed at the tip, and is generated from vehicle interior air or outside air by the gas filter 26A. The clean air is sent to the suction concentration unit 22 through the clean air introduction pipe 26.

  The ethanol concentration detection apparatus 10 includes a concentrated air introduction pipe 28 for introducing the gas concentrated by the suction concentration unit 22. In addition, an alcohol sensor 30 for detecting the concentration of ethanol gas and a measurement cell (not shown) are attached inside the intermediate portion of the concentrated air introduction pipe 28. The concentrated air introduction pipe 28 introduces the gas concentrated by the suction concentration unit 22 into the measurement cell, and the ethanol sensor concentration (ppm) in the gas introduced into the measurement cell is measured by the alcohol sensor 30.

  The alcohol sensor 30 is a sensor that detects ethanol gas. For example, TGS822 (trade name, manufactured by Figaro Engineering Co., Ltd.) using a tin oxide semiconductor can be used.

  As shown in FIG. 3, the suction concentrating unit 22 sucks and collects ethanol gas components in air containing exhaled air (hereinafter, exhaled air) filled with an ethanol collecting adsorbent (eg, silica gel). A first collecting tube 50 as a collecting portion, a second collecting tube 52 as a collecting portion for sucking and collecting ethanol gas components in the air in the passenger compartment filled with an ethanol collecting adsorbent, While switching the gas flow path of the air in the exhalation introduction pipe 20 so that it may open to either the 1st collection pipe 50 or the 2nd collection pipe 52, the gas flow path of the clean air from the clean air introduction pipe 26 is changed. The first collection tube 50 and the second collection tube 52 were collected by each of the first collection tube 50 and the first collection tube 50 and the second collection tube 52 for switching to open to either the first collection tube 50 or the second collection tube 52. Ethanol gas components in exhaled air and ethanol gas composition in passenger compartment air And the second valve 56 for introducing the alcohol sensor 30 via the concentrated air introduction pipe 28 and the first collection pipe 50 or the second collection pipe 52 by operating the second valve 56. A pump 58 that sucks air and introduces the ethanol component sucked and collected in the first collecting tube 50 and the second collecting tube 52 into the alcohol sensor 30, and the first collecting tube 50 and the second collecting tube. The adsorbent for ethanol collection provided so as to surround each of the 52 and filled in each of the first collection pipe 50 and the second collection pipe 52 is heated and adsorbed on the adsorbent for ethanol collection. And a heating furnace (not shown) for heat desorption for desorbing the ethanol gas component in the exhaled air and the ethanol gas component in the passenger compartment air.

  The switching of the first valve 54 and the second valve 56, the operation of the pump 58, and the temperature control of the heating furnace are performed from the control unit 32, which will be described later, from the first valve 54, the second valve 56, the pump 58, and the heating furnace. It is controlled by a control signal input to. The pump 58 is sucked at a constant flow rate for simplicity.

  The ethanol concentration detection device 10 is connected to the oxygen sensor 24, the alcohol sensor 30, and the suction concentration unit 22, and includes a control unit 32 that controls the suction concentration unit 22 and calculates the concentration of ethanol gas in exhaled breath. ing.

  The control unit 32 is configured by a computer, and includes a CPU, a ROM that stores programs, a RAM that stores data, and a bus that connects these. If this control part 32 is demonstrated with the functional block divided | segmented for every function implementation | achievement means determined based on hardware and software, as shown in FIG. 3, based on the output density | concentration from the oxygen sensor 24, the exhalation introduction pipe | tube 20 Determining whether or not exhaled air is contained in the air flowing inside, and an exhalation determining unit 40 that outputs an output concentration from the oxygen sensor 24 when exhaled is included and when exhaled is not included, An aspiration time setting unit 41 that sets the aspiration time, a suction / desorption control unit 42 that controls the aspiration concentration unit 22 according to the determination result of the exhalation determination unit 40, a case where exhalation is included and a case where exhalation is not included Ethanol concentration for calculating the concentration of ethanol gas contained in exhaled air based on the output concentration from the oxygen sensor 24 and the output concentration from the alcohol sensor 30 And a detecting section 44.

  The exhalation determination unit 40 determines whether or not exhalation is contained in the gas in the exhalation introduction tube 20 based on the change in the output concentration of the oxygen sensor 24, and the output concentration of the oxygen sensor 24 is below a predetermined concentration Then, it is determined that exhalation is included, and an exhalation start signal is output to the suction / desorption control unit 42. On the other hand, the expiration determination unit 40 determines that expiration is not included when the output concentration of the oxygen sensor 24 exceeds a predetermined concentration, and outputs an expiration end signal to the suction / desorption control unit 42. The exhalation determination unit outputs the output concentration of the oxygen sensor 24 when it is determined that exhalation is included as the oxygen concentration in the exhalation air, and also when the oxygen sensor 24 determines that exhalation is not included The output concentration is output to the ethanol concentration calculation unit 44 as the oxygen concentration in the passenger compartment air.

  The predetermined concentration for determining whether or not exhalation is included is set in advance, or is calculated using at least one of the average value, the maximum value, and the minimum value of the immediately preceding predetermined time. do it. For example, an average value for 10 seconds immediately before the determination is set as a predetermined concentration for determining whether or not exhalation is included.

  The suction time setting unit 41 sets the suction time input by the operation of the operation unit (not shown) corresponding to the required sensitivity and time resolution.

  The suction / desorption control unit 42 controls the operation of the pump 58, and the suction concentration unit according to the suction time set by the suction time setting unit 41 and the expiration start signal and expiration end signal input from the expiration determination unit 40 The gas flow path by the first valve 54 of 22 is switched, and the ethanol gas component in the expiration air and the ethanol gas component in the passenger compartment air are sucked into the first collection pipe 50 and the second collection pipe 52, respectively. Collect.

  As shown in FIG. 4, when the exhalation start signal is input from the exhalation determination unit 40, the first valve 54 is switched to open the gas flow path to the first collection pipe 50, and the inside of the exhalation introduction pipe 20. The ethanol gas component in the exhaled air is sucked and collected in the first collecting tube 50. Further, when the expiration end signal is input from the expiration determination unit 40, the second valve 56 is switched to open the gas flow path to the second collection pipe 52, and the air in the cabin inside the expiration introduction pipe 20 The ethanol gas component is sucked and collected in the second collection tube 52.

  Here, in order to measure the ethanol gas concentration in the driver's exhalation air with appropriate sensitivity, distinguishing it from the ethanol gas component in the passenger compartment air, it is necessary to achieve both high sensitivity by concentration and ensuring time resolution. is necessary. Therefore, the length of the suction time is set according to the required sensitivity and time resolution, and the ethanol gas component in the exhalation air and the ethanol gas component in the passenger compartment air are distinguished, and each is concentrated and collected. Detect the ethanol gas concentration.

In the present embodiment, the above suction time is set to a time longer than ½ of the breathing time (about 3 seconds), for example, 5 seconds in order to increase the sensitivity by concentration. The suction / desorption control unit 42 performs control so that the ethanol gas component in the expiration air is sucked and collected until the cumulative expiration time (T _r1 + T _r2 + T _r3 + T _r4 ) of the expiration air reaches the set time (5 seconds). .

  When the cumulative suction time of expiratory air reaches the set time (5 seconds), the suction / desorption control unit 42 switches the gas flow path by the first valve 54 of the suction concentrating unit 22 and the first trapping air from the clean air introduction pipe 26. The first valve 54 is controlled to open the gas flow path to the collecting pipe 50, and the gas flow path by the second valve 56 is switched to open the gas flow path from the first collecting pipe 50 to the alcohol sensor 30. Thus, the second valve 56 is controlled. The suction / desorption control unit 42 controls the heating furnace so that the ethanol gas component in the exhaled air adsorbed by the ethanol collection adsorbent of the first collection tube 50 is desorbed and released, and is operated. The clean air is caused to flow from the clean air introduction pipe 26 to the first collection pipe 50 by the pump 58 therein, and the ethanol gas component in the exhaled air collected by suction is introduced into the alcohol sensor 30. When the detection of the ethanol gas component in the exhaled air by the alcohol sensor 30 is completed, the suction / desorption control unit 42 switches the gas flow path by the first valve 54 of the suction concentrating unit 22, and the second capture from the clean air introduction pipe 26. The first valve 54 is controlled to open the gas flow path to the collecting pipe 52, and the gas flow path by the second valve 56 is switched to open the gas flow path from the second collecting pipe 52 to the alcohol sensor 30. Thus, the second valve 56 is controlled. The suction / desorption control unit 42 controls the heating furnace so that the ethanol gas component in the passenger compartment air adsorbed by the ethanol collection adsorbent of the second collection pipe 52 is desorbed and released, and Clean air is caused to flow from the clean air introduction pipe 26 to the second collection pipe 52 by the pump 58 that is in operation, and the ethanol gas component in the vehicle interior air sucked and collected is introduced into the alcohol sensor 30.

  The ethanol concentration calculation unit 44 outputs the oxygen concentration in the expiratory air and the oxygen concentration in the passenger compartment air output from the expiratory determination unit 40, the ethanol gas concentration in the expiratory air detected by the alcohol sensor 30, and the passenger compartment air. Based on the ethanol gas concentration and the oxygen concentration in the exhaled breath determined in advance, the ethanol gas concentration in the exhaled breath is calculated. Here, the oxygen concentration in the exhalation is a substantially constant concentration, for example, about 16%.

  As will be described below, the ethanol concentration calculation unit 44 calculates the dilution rate of the detected exhalation air (a factor indicating how many times the driver exhalation has been diluted), the ethanol gas concentration in the exhalation air, the vehicle interior From the ethanol gas concentration in the air and the dilution factor, the ethanol gas concentration in the driver's breath is calculated.

Assuming that the ethanol gas concentration in the exhaled air detected by the alcohol sensor 30 is the ethanol concentration 1 and the ethanol gas concentration in the passenger compartment air is the ethanol concentration 2, first, per unit expiratory air amount according to the following equation (1): Calculate the ethanol concentration.
Ethanol concentration per unit exhaled air volume (E _breath ) =
Ethanol concentration 1 x Desorption air volume ÷ Exhalation air suction volume (1)

However, the desorption air amount is an amount obtained from the product of the operating time when the pump 58 is operated when performing heat desorption and the constant flow rate of the pump 58, and the exhalation air suction amount is the first collection pipe 50 for the exhalation air. This is an amount obtained from the product of the operating time (equivalent to the suction time _Tr ) when the pump is operated when sucking into the pump 58 and the constant flow rate of the pump 58.

Further, the ethanol concentration per unit passenger compartment air amount is calculated by the following equation (2).
Ethanol concentration per unit cabin air volume (E _base ) =
Ethanol concentration 2 x Desorption air volume ÷ Car interior air suction volume (2)

However, room air suction amount (equal to the suction time T _b to be described later) operation time was operating the pump when sucking the room air into the second collecting tube 52 from the product of the constant flow pump 58 This is the required amount.

Then, the oxygen concentration per unit expiratory air amount is calculated by the following equation (3).
Oxygen concentration per unit expiratory air volume (O _breath ) =
Integral value of oxygen concentration in exhaled air during aspiration period ÷ exhaled air aspiration amount (3)

Next, the oxygen concentration per unit passenger compartment air amount is calculated by the following equation (4).
Oxygen concentration per unit passenger compartment air volume (O _base ) =
The integrated value of the oxygen concentration in the passenger compartment air during the suction period ÷ the passenger compartment air suction amount (4)

And the ethanol gas density | concentration in a driver | operator's expiration is calculated by the following (5) Formula.
Ethanol gas concentration in the exhalation of the driver =
(E _breath -E _base ) * (O ₀ -O _base ) / (O _breath -O _base ) + E _base
... (5)
However, O ₀ represents the oxygen concentration in the expired air (about 16%), and (O ₀ -O _base ) / (O _breath -O _base ) represents the dilution rate of the detected exhaled air.

  Next, the operation of the ethanol concentration detection apparatus 10 according to the first embodiment will be described. When the driver is seated on the vehicle seat, the exhalation of the driver is blown into the exhalation introduction tube 20, and when the ignition switch is turned on by the driver, the expiration determination process shown in FIG. The routine is executed. The case where the suction time is preset by the driver will be described as an example.

  First, in step 100, the output concentration from the oxygen sensor 24 is acquired. In step 102, whether the output concentration acquired in step 100 is equal to or less than a predetermined concentration (average value of oxygen concentration in the immediately preceding 10 seconds). If the output concentration from the oxygen sensor 24 is greater than the predetermined concentration, it is determined that the air in the exhalation introduction tube 20 does not contain exhalation, and the process returns to step 100 described above. On the other hand, when the output concentration from the oxygen sensor 24 is equal to or lower than the predetermined concentration, it is determined that exhalation is contained in the air in the exhalation introduction tube 20, and in step 104, the aspiration / desorption control unit 42 starts exhalation. Output a signal.

  In step 106, the output concentration from the oxygen sensor 24 is acquired. In step 108, it is determined whether the output concentration acquired in step 106 is greater than a predetermined concentration. The output concentration from the oxygen sensor 24 is determined. Is equal to or lower than the predetermined concentration, it is determined that exhaled air is contained in the air in the exhalation-introducing tube 20, and the process returns to step 106. On the other hand, if the output concentration from the oxygen sensor 24 is greater than the predetermined concentration, it is determined that the air in the exhalation introduction tube 20 does not contain exhalation, and in step 110, the expiration / desorption control unit 42 is notified of the expiration end signal. Is output and the process returns to step 100.

  As described above, when the exhalation determination processing routine is executed, the driver blows exhalation into the exhalation introduction tube 20, and when exhalation is included in the air in the exhalation introduction tube 20, an exhalation start signal is sent to the suction / desorption control unit 42. Is output. Further, when the driver stops blowing exhalation into the exhalation introduction tube 20 and exhalation is not included in the air in the exhalation introduction tube 20, an exhalation end signal is output to the suction / desorption control unit 42.

Further, a suction / desorption process routine shown in FIG. 6 is executed in the control unit 32 of the ethanol concentration detection apparatus 10. First, in step 118, the pump 58 is operated so as to suck inhaled inhalation into the exhalation introduction tube 20. In step 120, each of the variable T _r representing the expiration time of the exhalation air and the variable T _b representing the inhalation time of the vehicle interior air is set to an initial value of 0. In step 122, the expiration / desorption control unit 42 is inhaled. It is determined whether a start signal is input. When the exhalation start signal is input to the suction / desorption control unit 42, the process proceeds to step 124, and the switching of the first valve 54 is controlled so as to open the gas flow path to the first collection pipe 50. As a result, the exhaled air in the exhalation introducing tube 20 is sucked, and the ethanol gas component in the exhaled air is collected in the first collecting tube 50. In the next step 127, the output concentration from the oxygen sensor 24 is acquired as the oxygen concentration in the expired air.

In step 128, it is determined whether or not an expiration end signal has been input. When the expiration end signal is not input, the process returns to step 127. On the other hand, when the expiration end signal is input to the suction / desorption control unit 42, the process proceeds to step 130, and the expiration air is sucked into the first collection tube 50. Add the suction time to _Tr .

In the next step 131, suction time T _r is determined whether or not more than 5 seconds is set time, if the suction time T _r has not reached the set time, it proceeds to step 132, On the other hand, when the suction time _Tr has reached the set time, in step 133, the heat desorption process in the first collection tube 50 is started, and the process proceeds to step 132. In step 133, the switching of the second valve 56 is controlled so that the ethanol gas component in the exhaled air collected in the first collection pipe 50 is introduced into the alcohol sensor 30, and the gas filter 26A generates the ethanol gas component. The switching of the first valve 54 is controlled so that the clean air flows to the first collecting pipe 50. Further, the temperature of the heating furnace is controlled, and the ethanol gas component in the exhaled air adsorbed by the ethanol collection adsorbent is heated and desorbed in the first collection tube 50 and introduced into the alcohol sensor 30.

  In step 132, switching of the first valve 54 is controlled so that the gas flow path to the second collection pipe 52 is opened. As a result, the vehicle interior air in the exhalation introduction tube 20 is sucked and the ethanol gas component in the vehicle interior air is collected in the second collection tube 52. In the next step 135, the output concentration from the oxygen sensor 24 is acquired as the oxygen concentration in the passenger compartment air.

In the next step 136, it is determined whether or not an exhalation start signal has been input. If the exhalation start signal is not input, the process returns to step 135. However, if the exhalation start signal is input to the suction / desorption control unit 42, the process proceeds to step 138, where the air in the vehicle compartment is sucked into the second collection pipe 52. the suction time is added to _{T b.} Then, in step 140, suction time T _r is determined whether or not more than 5 seconds is set time, if the suction time T _r has not reached the set time, the process returns to step 124, whereas If the suction time _Tr has reached the set time, the process proceeds to step 144.

  In step 144, the concentration output from the alcohol sensor 30 when the ethanol gas component in the collected exhaled air is heated and desorbed in step 133 and introduced into the alcohol sensor 30 is determined as the ethanol gas concentration in the exhaled air. Get as.

  In step 146, the heat desorption process in the second collection tube 52 is started. In step 146, the switching of the second valve 56 is controlled so that the ethanol gas component in the passenger compartment air collected in the second collecting pipe 52 is introduced into the alcohol sensor 30, and is generated by the gas filter 26A. The switching of the first valve 54 is controlled so that the purified air that has been flowed into the second collection pipe 52. Further, the temperature of the heating furnace is controlled, and the ethanol gas component in the passenger compartment air adsorbed by the ethanol collection adsorbent in the second collection tube 52 is heated and desorbed and introduced into the alcohol sensor 30.

  In the next step 148, the concentration output from the alcohol sensor 30 when the collected ethanol gas component in the passenger compartment air is heated and desorbed and introduced into the alcohol sensor 30 is determined as the ethanol gas concentration in the passenger compartment air. Get as.

In step 150, the oxygen concentration in the exhalation air acquired in step 127, the oxygen concentration in the passenger compartment air acquired in step 135, the suction time T _r , the suction time T _b , and the above acquired in step 144. Using the ethanol gas concentration in the exhaled breath and the ethanol gas concentration in the passenger compartment air acquired in step 148, the ethanol gas concentration in the driver's breath according to the above formulas (1) to (5) Is calculated. In step 152, the ethanol gas concentration in the breath calculated in step 150 is displayed on a display unit (not shown) provided in the passenger compartment, and the suction / desorption processing routine is terminated.

  As described above, according to the ethanol concentration detection apparatus according to the first embodiment, when exhaled air is contained in the exhalation introduction tube, the exhaled air is sucked to collect the ethanol gas component. Since the ethanol gas components in the exhaled air can be distinguished and collected and the concentration of the ethanol gas in the exhaled air can be detected, the ethanol gas in the exhaled breath can be detected by simply breathing naturally without inhaling the exhaled air. Can be detected with high sensitivity and high accuracy.

  Further, according to the determination result of whether or not exhalation is contained in the air in the exhalation introduction tube, the exhalation air and the vehicle interior air are distinguished by switching the collection tube and collecting the ethanol gas component. And the density | concentration of ethanol gas is detectable about each of vehicle interior air.

  Further, based on the oxygen concentration in the air in the exhalation introduction tube detected by the oxygen sensor, it can be accurately determined whether or not exhalation is included.

  Further, since the exhaled air is sucked for a predetermined suction time and the ethanol gas component is concentrated and collected, the ethanol gas concentration can be detected with a desired sensitivity.

  Also, according to the required sensitivity and time resolution, the length of the suction time is set, the breath air and the passenger compartment air are distinguished and sucked into separate collection pipes, and the collected ethanol gas components are used. By detecting the ethanol gas concentration, the ethanol gas concentration in the exhaled air can be detected with appropriate sensitivity and time resolution. Moreover, the expiration dilution rate at the time of detection can be calculated, and the concentration of ethanol gas in the expiration before being diluted can be calculated using the expiration dilution rate. As a result, the ethanol gas concentration in the driver exhalation can be selectively detected with appropriate sensitivity without inhaling exhalation.

  Next, an ethanol concentration detection apparatus according to the second embodiment will be described. In addition, about the part which becomes the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The second embodiment is different from the first embodiment in that the suction time is set short in order to obtain a high time resolution.

  In the control unit 32 of the ethanol concentration detection apparatus 10 according to the second embodiment, the suction time setting unit 41 sets the suction time of the suction / desorption control unit 42 to 1 second, for example. Further, each of the first collection pipe 50 and the second collection pipe 52 sucks and collects both the ethanol gas component in the exhaled air and the ethanol gas component in the passenger compartment air.

  The suction / desorption control unit 42 controls the operation of the pump 58, and the suction concentration unit according to the suction time set by the suction time setting unit 41 and the expiration start signal and expiration end signal input from the expiration determination unit 40 The gas flow path by the first valve 54 of 22 is switched, and the air in the exhalation introduction pipe 20 is sucked into each of the first collection pipe 50 and the second collection pipe 52 to collect ethanol gas components in the air. To do.

  As shown in FIG. 7, the gas flow path to either one of the first collection pipe 50 and the second collection pipe 52 is opened every set suction time (1 second), and the inside of the exhalation introduction pipe 20 By switching the first valve 54 so as to suck in the air, the ethanol gas component in the air in the breath introduction pipe 20 is alternately sucked and collected in the first collecting pipe 50 and the second collecting pipe. To do.

  In addition, even during the suction for 1 second, when the expiration start signal or the expiration end signal is input from the expiration determination unit 40, the switching of the first valve 54 is controlled, and the collection tube for aspiration collection is controlled. Switch from one of the first collection tube 50 and the second collection tube to the other.

  When the set suction time (1 second) ends, or when an expiration start signal or an expiration end signal is input from the expiration determination unit 40 and the suction collection into the first collection tube 50 ends, the suction / desorption control The unit 42 controls the first valve 54 so as to open the gas flow path from the clean air introduction pipe 26 to the first collection pipe 50 by switching the gas flow path by the first valve 54 of the suction concentration section 22. The second valve 56 is controlled so as to open the gas flow path from the first collection pipe 50 to the alcohol sensor 30 by switching the gas flow path by the second valve 56. The suction / desorption control unit 42 controls the heating furnace so that the ethanol gas component in the exhaled air or the cabin air adsorbed by the ethanol collecting adsorbent of the first collecting tube 50 is heated and desorbed. Then, clean air is caused to flow from the clean air introduction pipe 26 to the first collection pipe 50 by the pump 58 in operation, and the ethanol gas component in the aspirated and collected exhalation air or vehicle interior air is introduced into the alcohol sensor 30. To do.

  In addition, when the set suction time (1 second) ends, or when the expiration start signal or the expiration end signal is input from the expiration determination unit 40 and the suction collection to the second collection tube 52 ends, The suction / desorption control unit 42 switches the gas flow path using the first valve 54, switches the gas flow path using the second valve 56, and the heating furnace, similarly to the case where the suction collection to the first collection pipe 50 is completed. And the ethanol gas component in the exhaled air or in the passenger compartment air sucked and collected in the second collecting tube 52 is introduced into the alcohol sensor 30.

  Next, the contents of the suction / desorption processing routine according to the second embodiment will be described with reference to FIG. In addition, about the process similar to 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  First, in step 118, the pump 58 is operated so as to suck inhaled inhalation into the exhalation introduction tube 20. In step 122, it is determined whether or not an exhalation start signal is input to the suction / desorption control unit 42. When the exhalation start signal is input to the suction / desorption control unit 42, the process proceeds to step 124, and the switching of the first valve 54 is controlled so as to open the gas flow path to the first collection pipe 50. As a result, the air in the exhalation introduction tube 20 (initially exhaled air) is sucked into the first collecting tube 50, and the ethanol gas component in the air (initially exhaled air) is sucked into the first collecting tube 50. Be collected. In the next step 127, the output concentration from the oxygen sensor 24 is acquired as the oxygen concentration in the expiratory air or in the passenger compartment air (initially, the oxygen concentration in the expiratory air).

  In step 250, whether an expiration start signal or expiration end signal is input to the suction / desorption control unit 42, or whether the suction time to the first collection tube 50 has reached a set time (1 second). Determine. If neither the exhalation start signal nor the exhalation end signal is input and the aspiration time has not reached the set time, the process returns to step 127. On the other hand, when the expiration start signal or the expiration end signal is input, or when the aspiration time reaches the set time, the process proceeds to step 133.

  In step 133, the heat desorption process in the first collection tube 50 is started. In step 133, switching of the second valve 56 is controlled so that the ethanol gas component collected in the first collection pipe 50 is introduced into the alcohol sensor 30, and clean air is supplied to the first collection pipe 50. The switching of the first valve 54 is controlled so as to flow. Further, the temperature of the heating furnace is controlled, and the ethanol gas component adsorbed on the first collection pipe 50 is heated and desorbed and introduced into the alcohol sensor 30. In step 132, switching of the first valve 54 is controlled so as to open the gas flow path to the second collection pipe 52. As a result, the air in the exhalation introduction pipe 20 is sucked into the second collection pipe 52, and the ethanol gas component in the air in the exhalation introduction pipe 20 is sucked and collected in the second collection pipe 52.

  In the next step 144, the concentration output from the alcohol sensor 30 is acquired as the ethanol gas concentration in the exhaled air or the passenger compartment air. Note that whether the ethanol gas concentration in the exhalation air or the ethanol gas concentration in the passenger compartment air is determined based on whether the signal input immediately before is the exhalation start signal or the exhalation end signal. Good.

  In step 135, the output concentration from the oxygen sensor 24 is acquired as the oxygen concentration in the exhaled air or the passenger compartment air.

  In step 252, whether an expiration start signal or expiration end signal is input to the suction / desorption control unit 42, or whether the suction time to the second collection tube 52 has reached a set time (1 second). Determine. If neither the exhalation start signal nor the exhalation end signal is input and the aspiration time has not reached the set time, the process returns to step 135. On the other hand, when the expiration start signal or expiration end signal is input or when the aspiration time reaches the set time, the process proceeds to step 146.

  In step 146, the heat desorption process in the second collection tube 52 is started. In step 146, switching of the second valve 56 is controlled so that the ethanol gas component collected in the second collection pipe 52 is introduced into the alcohol sensor 30, and clean air is supplied to the second collection pipe 52. The switching of the first valve 54 is controlled so as to flow. Further, the temperature of the heating furnace is controlled, and the ethanol gas component adsorbed on the second collection pipe 52 is heated and desorbed and introduced into the alcohol sensor 30.

  In the next step 253, switching of the first valve 54 is controlled so as to open the gas flow path to the first collection pipe 50. As a result, the air in the breath introduction pipe 20 is sucked into the first collection pipe 50 and the ethanol gas component in the air is sucked and collected in the first collection pipe 50.

  In the next step 148, the concentration output from the alcohol sensor 30 is acquired as the ethanol gas concentration in the exhaled air or the passenger compartment air.

  In step 254, it is determined whether or not the suction concentration process is to be terminated. For example, it is determined whether or not the ethanol gas concentration has been acquired from the alcohol sensor 30 the number of times set as the termination condition. If the number has not been reached, the process returns to step 127. On the other hand, if the set number has been reached, the process proceeds to step 256.

  In step 256, the oxygen concentration in the expiratory air or the passenger compartment air acquired in step 127, the oxygen concentration in the expiratory air or the passenger compartment air acquired in step 135, and the oxygen concentration obtained in step 144. In the same manner as in the first embodiment, the ethanol gas concentration in the expired air or the vehicle interior air and the ethanol gas concentration in the expired air or the vehicle interior air acquired in step 148 are used. According to the equations (1) to (5), the concentration of ethanol gas in the driver's breath is calculated. In step 258, the ethanol gas concentration in the breath calculated in step 256 is displayed on the display unit provided in the passenger compartment, and the suction / desorption processing routine is terminated.

  As described above, according to the ethanol concentration detection apparatus according to the second embodiment, the collection tube is switched every time suction is performed for a predetermined suction time, and ethanol gas components are collected. By detecting the concentration, the concentration of ethanol gas can be detected with a desired time resolution. In addition, the concentration of ethanol gas in exhaled breath can be detected with high time resolution by setting the suction time to a short time.

  Further, by shortening the suction time, the ethanol gas concentration can be detected in a short time.

  Next, an ethanol concentration detection apparatus according to a third embodiment will be described. In addition, about the part which becomes the structure similar to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The third embodiment is different from the first embodiment in that a carbon dioxide sensor that detects carbon dioxide is used as a reference gas.

  In the ethanol detection device according to the third embodiment, a carbon dioxide sensor that detects the concentration of carbon dioxide is attached to the inside of the exhalation introduction tube 20, and the output concentration of the carbon dioxide sensor is controlled by the control unit 32. Is input.

  The carbon dioxide sensor is a sensor that detects carbon dioxide contained in the gas flowing in the breath introduction pipe 20, and for example, CDM4160 (trade name, manufactured by Figaro Giken Co., Ltd.) using a solid electrolyte can be used.

  Note that when the concentration of carbon dioxide is used as the concentration of the reference gas, the concentration in the exhalation increases as compared to the atmosphere, as opposed to the case of using the concentration of oxygen. It will increase from the output concentration of the carbon dioxide sensor in the atmosphere.

  The exhalation determination unit 40 of the control unit 32 determines whether or not exhalation is contained in the gas in the exhalation introduction tube 20 based on the change in the output concentration of the carbon dioxide sensor, and the output concentration of the carbon dioxide sensor is predetermined. When the concentration is equal to or higher than the concentration, it is determined that exhalation is included, and an exhalation start signal is output to the suction / desorption control unit 42. On the other hand, when the output concentration of the carbon dioxide sensor becomes less than the predetermined concentration, it is determined that exhalation is not included, and an expiration end signal is output to the suction / desorption control unit 42. The exhalation determination unit outputs the output concentration of the carbon dioxide sensor when it is determined that exhalation is included as the carbon dioxide concentration in the exhalation air, and the carbon dioxide sensor when it is determined that exhalation is not included Is output to the ethanol concentration calculator 44 as the carbon dioxide concentration in the passenger compartment air.

  The ethanol concentration calculation unit 44 outputs the carbon dioxide concentration in the exhaled air and the carbon dioxide concentration in the vehicle interior air output from the exhalation determining unit 40, the ethanol gas concentration in the exhaled air detected by the alcohol sensor 30, and the vehicle interior. Based on the ethanol gas concentration in the air and the carbon dioxide concentration in the exhalation obtained in advance, the ethanol gas concentration in the exhalation is calculated in the same manner as in the first embodiment. Here, the carbon dioxide concentration in the exhalation is a substantially constant concentration, for example, about 40000 ppm.

  Next, an ethanol concentration detection apparatus according to a fourth embodiment will be described. The fourth embodiment is different from the first embodiment in that a water vapor sensor that detects water vapor is used as a reference gas.

  In the ethanol detection apparatus according to the fourth embodiment, a water vapor sensor for detecting the concentration of water vapor is attached to the inside of the exhalation introduction tube 20, and the output concentration of the water vapor sensor is input to the control unit 32. The

  As the water vapor sensor, TGS2180 (trade name, manufactured by Figaro Giken Co., Ltd.) using a tin oxide semiconductor can be used. Further, a water vapor sensor using a polymer film capacitance may be used.

  Note that when the concentration of water vapor is used as the concentration of the reference gas, the concentration in the exhalation increases compared to the air, as opposed to the case of using the oxygen concentration. The output concentration of the water vapor sensor will increase.

  The expiration determination unit 40 of the control unit 32 determines whether or not expiration is contained in the gas in the expiration introduction tube 20 based on the change in the output concentration of the water vapor sensor, and the output concentration of the water vapor sensor is a predetermined concentration. When the above is reached, it is determined that exhalation is included, and an exhalation start signal is output to the suction / desorption control unit 42. On the other hand, when the output concentration of the water vapor sensor becomes less than the predetermined concentration, it is determined that exhalation is not included, and an exhalation end signal is output to the suction / desorption control unit 42. The breath determination unit outputs the output concentration of the water vapor sensor when it is determined that exhalation is included as the water vapor concentration in the exhalation air, and the output concentration of the water vapor sensor when it is determined that exhalation is not included Is output to the ethanol concentration calculator 44 as water vapor in the passenger compartment air.

  The ethanol concentration calculation unit 44 outputs the water vapor concentration in the expiratory air and the water vapor concentration in the passenger compartment air output from the expiratory judgment unit 40, the ethanol gas concentration in the expiratory air detected by the alcohol sensor 30, and the air in the passenger compartment air. Based on the ethanol gas concentration and the water vapor concentration in the exhaled breath, the ethanol gas concentration in the exhaled breath is calculated in the same manner as in the first embodiment. Here, the water vapor concentration in the exhalation is a substantially constant concentration, for example, a value of a saturated water vapor concentration of 34 ° C., for example.

  In the above embodiment, the case of calculating the concentration of ethanol gas in exhaled breath according to the above formulas (1) to (5) has been described as an example. However, the present invention is not limited to this. The concentration of ethanol gas in exhaled breath may be calculated according to any one of the formulas (1) to (8).

Ethanol gas concentration = (Δa / Δb) (6)
Ethanol gas concentration = (Δa / Δb) · BG (7)
Ethanol gas concentration = (Δa / Δb) · (BG-AG)
+ [EtOH] base (8)

  Where Δa is the amount of change in ethanol gas concentration in the exhaled air, rate of change, or integral value within a predetermined time, Δb is the amount of change in oxygen concentration detected by an oxygen sensor, etc., rate of change, Or, an integrated value within a predetermined time, BG is a concentration of oxygen in the exhaled breath obtained in advance, AG is a concentration of oxygen in the passenger compartment air detected by an oxygen sensor or the like, and [EtOH] base is an alcohol sensor It is the concentration of ethanol gas in the detected cabin air.

  Moreover, although the case where it comprised using the alcohol sensor and the oxygen sensor, the carbon dioxide sensor, or the water vapor sensor was demonstrated to the example, it is not limited to this, As a structure which detects a carbon dioxide concentration, carbon dioxide Provided with a carbon dioxide detector comprising an optical filter for carbon and a converter for converting infrared light transmitted through the optical filter for carbon dioxide into an electrical signal, or a carbon dioxide sensor comprising a light source emitting infrared light and an infrared detector It is good also as a structure. In addition, as a configuration for detecting the water vapor concentration, a water vapor detection unit including an optical filter for water vapor and a conversion unit that converts infrared light transmitted through the optical filter for water vapor into an electrical signal, or a light source that emits infrared light and an infrared detector. It is good also as a structure which provided the comprised water vapor | steam sensor.

  Further, as a configuration for detecting the concentration of ethanol gas, an ethanol detector including an optical filter for ethanol and a conversion unit that converts infrared light transmitted through the optical filter for ethanol into an electrical signal, or a light source and infrared detector that emits infrared light It is good also as a structure which provided the alcohol sensor comprised by these.

  In addition, the case where the calculated concentration of ethanol gas in the expiration is displayed has been described as an example. However, the present invention is not limited to this. For example, the calculated ethanol gas concentration is compared with a predetermined threshold value to calculate If the ethanol gas concentration is equal to or higher than the threshold value, it may be determined that the ethanol concentration is high, and control such that the engine cannot be started is prevented.

  In the suction / desorption process routine, the case where the ethanol gas concentration in the exhalation is calculated only once has been described as an example. However, the present invention is not limited to this, and a series of processes for calculating the ethanol gas concentration is repeated. You may make it perform.

  In the above, the example of detecting ethanol from the exhalation of the driver has been described, but the present invention can be applied to the case of detecting ethanol from exhalation of humans other than the driver by configuring the ethanol concentration detection device to be portable. It is.

It is the schematic which shows the state which attached the ethanol concentration detection apparatus of this Embodiment to the steering column of a driver's seat. It is the schematic which shows the 1st Embodiment of this invention. It is a block diagram which shows the structure of the control part and suction concentration part of the 1st Embodiment of this invention. It is an image figure which shows a mode that the collection tube to collect is switched according to the input of the expiration start signal and the expiration end signal. It is a flowchart which shows the content of the expiration determination processing routine of the ethanol concentration detection apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the content of the suction / desorption process routine of the ethanol concentration detection apparatus which concerns on the 1st Embodiment of this invention. It is an image figure which shows a mode that the collection tube to collect is switched for every suction time. It is a flowchart which shows the content of the suction / desorption process routine of the ethanol concentration detection apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ethanol concentration detection apparatus 20 Exhalation introduction pipe 22 Suction concentration part 24 Oxygen sensor 26A Gas filter 26 Clean air introduction pipe 28 Concentrated air introduction pipe 30 Alcohol sensor 32 Control part 40 Exhalation judgment part 42 Suction desorption control part 44 Ethanol concentration calculation part 50 First collection pipe 52 Second collection pipe 54 First valve 56 Second valve 58 Pump

Claims (10)

Expiration determination means for determining whether or not expiration is included in the gas to be detected;
Aspiration collecting means for sucking the detection target gas and collecting a detection target gas component when it is determined by the expiration determination means that exhalation is included;
A detection target gas concentration detection means for discharging the detection target gas component collected by the suction collection means and detecting the concentration of the detection target gas;
Calculation means for calculating the concentration of the detection target gas in the expiration based on the concentration of the detection target gas detected by the detection target gas concentration detection means;
A gas concentration detection apparatus including: Reference gas concentration detection means for detecting the concentration of the reference gas contained in the gas to be detected is further included,
2. The gas concentration detection according to claim 1, wherein the expiration determination unit determines whether or not expiration is included in the gas to be detected based on the concentration of the reference gas detected by the reference gas concentration detection unit. apparatus.   The calculation means is configured to detect the detection target gas in expired gas based on the concentration of the detection target gas detected by the detection target gas concentration detection means and the concentration of the reference gas detected by the reference gas concentration detection means. The gas concentration detection apparatus according to claim 2, wherein the concentration of the gas is calculated. The suction collection unit includes a plurality of collection units that collect the gas component to be detected, and switches to any of the plurality of collection units according to a determination result by the expiration determination unit, and the detection The target gas component is collected in the switched collection unit by sucking the target gas,
The detection target gas concentration detection means detects the concentration of the detection target gas by releasing the detection target gas component collected in each of the plurality of collection units,
The calculation means releases the detection target gas component of each of the plurality of collection units by the detection target gas concentration detection means, and detects the detection in expiration based on the concentration of the detection target gas detected respectively. The gas concentration detection apparatus according to claim 1, wherein the concentration of the target gas is calculated.   The gas concentration according to claim 4, wherein the detection target gas concentration detection means detects the concentration of the detection target gas by releasing the detection target gas component collected in the collection unit by suction for a predetermined suction time. Detection device. The suction collecting unit is switched to one of the plurality of collecting units according to a determination result by the exhalation determining unit, and is switched to any one of the plurality of collecting units for each suction for a predetermined suction time. Collecting the detection target gas component in the switched collection unit by sucking the detection target gas,
The detection target gas concentration detection means releases the detection target gas component collected in the collection unit and collects the concentration of the detection target gas each time the detection target gas component is collected in the collection unit. The gas concentration detection apparatus according to claim 4, which detects odor.   The suction collecting means switches a valve so as to open a gas flow path to any one of the plurality of collecting portions according to a determination result by the exhalation determining means, and the gas to be detected by operating a pump The gas concentration detection apparatus according to any one of claims 4 to 6, wherein the gas component to be detected is collected in the switched collection unit by sucking a gas. Reference gas concentration detection means for detecting the concentration of the reference gas contained in the gas to be detected is further included,
The calculation means includes a concentration of the detection target gas detected by discharging the detection target gas component of each of the plurality of collection units by the detection target gas concentration detection means, and expiration is included by the expiration determination means. The concentration of the reference gas detected by the reference gas concentration detection means when it is determined that the reference gas concentration is detected, and the detection of the reference gas concentration detection means when the expiration determination means determines that exhalation is not included. The gas concentration according to any one of claims 4 to 7, wherein the concentration of the detection target gas in the expiration is calculated based on the concentration of the reference gas and the concentration of the reference gas in the expiration determined in advance. Detection device.   The calculation means determines that the reference gas concentration detected by the reference gas concentration detection means when the expiration determination means determines that expiration is included, and the expiration determination means determines that no expiration is included. Sometimes, based on the concentration of the reference gas detected by the reference gas concentration detecting means and the concentration of the reference gas obtained in advance, the expiration dilution rate is calculated, the calculated expiration dilution rate, And the concentration of the detection target gas in the expiration based on the concentration of the detection target gas detected by releasing the detection target gas component of each of the plurality of collection units by the detection target gas concentration detection means The gas concentration detection apparatus according to claim 8, wherein The detection target gas is ethanol gas,
The gas concentration detection apparatus according to any one of claims 1 to 9, wherein the reference gas is any one of oxygen, carbon dioxide, and water vapor.

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