JP2009257772A - Gas sensor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas sensor device capable of detecting a specific gas in exhalation easily by an individual. <P>SOLUTION: This exhalation gas sensor device 10 includes an exhalation collection box 12; an outside air introduction part 24 for introducing a sample gas into the exhalation collection box 12; CNT (Carbon Nano Tube) gas sensors 40a, 40b, 40c provided in the exhalation collection box 12, and having each electric resistance changing by adsorbing a specific chemical substance; a detection part for detecting a change of the electric resistance of the CNT gas sensor 40a or the like; and exhaust parts 28, 29 for discharging gas inside the exhalation collection box 12 to the outside. Each of the CNT gas sensors 40a, 40b, 40c includes a CNT structure whose surface is modified by a material selected corresponding to the specific chemical substance which is a measuring object. A shutter 41 for separating the inside of the exhalation collection box 12 into two spaces may be provided in addition. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhalation gas sensor device that senses exhalation, and more particularly to an exhalation gas sensor device that can detect a plurality of types of gas components at a time.

  As modern Japan faces an aging society, society's overall interest in health is increasing. In this context, there is a need for improved technology related to health management, disease prevention and treatment.

  As a method of health management, for example, there is a system in which an individual can easily and quickly check a health condition. Examples of biological information that can be easily sampled in order to grasp an individual's health condition include blood, urine, sweat, saliva, and exhaled breath. Certain of these components may occur or change in amount due to poor physical condition, some indication of a high possibility of illness, or a disease already suffering. There is a high possibility that the health status of an individual can be grasped by knowing the change in the amount. Such a substance is called a marker. Marker monitoring is useful for health management, early detection of disease, and early treatment.

Among the biological information, exhaled breath is present in the lung in close proximity with blood in the capillaries across a thin film, and therefore contains a lot of markers in particular. Examples of markers included in exhaled breath include ethane and pentane caused by oxidative stress that is a cause of lifestyle-related diseases, NO and CO caused by respiratory diseases such as bronchitis, H ₂ caused by digestive diseases such as gastritis, For example, acetone due to diabetes. Among biometric information, sampling of exhalation is the simplest. For this reason, there is a particular need for a system for personal health management that senses expired gas.

  In expiratory gas sensing, the concentration of the marker contained in the expiratory gas is in the ppb to ppm level, and highly sensitive sensing is required. Furthermore, since the operation is performed by an individual, sensing that can be easily performed by anyone and that does not require large-scale facilities is required.

  In the technique described in Patent Document 1, the semiconductor sensor is composed of a component that adsorbs acetone, and the acetone concentration in the exhaled breath can be measured by the resistance change of the semiconductor sensor. Specifically, at high temperatures, tin oxide, zinc oxide, and indium oxide-based compounds constituting the semiconductor sensor adsorb oxygen molecules in the breath. As a result, the acetone in the breath is concentrated. Furthermore, tungsten, molybdenum, and chromium-based oxides that include elements selected from platinum, rhodium, and palladium that constitute the semiconductor sensor adsorb acetone and oxidize. Thereafter, the temperature of the semiconductor sensor is lowered, and the oxidized acetone is adsorbed by the tin oxide, zinc oxide and indium oxide compounds. This adsorption changes the energy band state of the tin oxide, zinc oxide and indium oxide compounds. As a result, the resistance of the semiconductor sensor decreases.

In an apparatus including a housing provided with the semiconductor sensor, when the breath is sucked into the housing, the apparatus displays the acetone concentration. According to this apparatus, it is possible to detect the acetone concentration of ppm level by a simple operation. Therefore, with respect to diabetes, this device can be used for personal health management, as well as disease prevention and treatment.
JP 2001-318069 A Riichiro Saito, “Outline and Issues of Carbon Nanotubes”, Functional Materials, vol. 21, no. 5, p. 6-14, May 2001 issue

  However, the semiconductor sensor described in Patent Document 1 cannot detect an exhalation component other than acetone. Therefore, information on diseases other than diabetes cannot be obtained.

  As a method for solving this problem, for example, there is gas chromatography (hereinafter referred to as “GC”). GC can detect multiple components in a single measurement. However, GC is not suitable for individuals to manage their own health because it is an expensive and large device and because it requires knowledge about GC in sampling and operation.

  Accordingly, an object of the present invention is to provide a gas sensor device that is relatively small in operating procedure and can be used for personal use, and that is relatively small.

  Another object of the present invention is that the operation procedure is simple enough to accommodate personal use and is relatively small, and a plurality of gas components in the gas to be measured can be selected with high sensitivity by a single measurement. It is to provide a gas sensor device that can be sensed automatically.

  A gas sensor device according to a first aspect of the present invention includes a housing in which a space is formed, a sample gas introduction unit that is provided in the housing and introduces a sample gas into the space inside the housing, A chemical substance sensing element that is provided in the housing and changes its electrical resistance by adsorbing a specific chemical substance in the atmosphere, and a chemical substance sensing element that is electrically coupled to the chemical substance sensing element. Detection means for detecting, and exhaust means provided in the housing for exhausting the gas in the space inside the housing to the outside of the housing. The chemical substance sensing element includes a carbon nanostructure that is surface-modified with a substance selected corresponding to the specific chemical substance.

  Preferably, the carbon nanostructure includes a carbon nanotube (hereinafter referred to as “CNT”).

  CNT is a tubular carbon material having a graphite structure and a nano-order diameter. CNTs have a very stable structure, and show conductivity within the inside that allows high-speed electron transfer based on negative electron bonds. Depending on the structure, CNTs are better conductors than metal wires. According to Non-Patent Document 1, when chemical substance molecules adhere to CNTs, electron transfer occurs and an electromotive force is generated. In other words, a potential difference, that is, a change in electric resistance occurs between two points of the CNT. If this change in electrical resistance is detected, chemical substances can be sensed. Furthermore, the CNT nanostructure can be expected to have excellent responsiveness and lower detection limit for sensing by CNT, and it can be said that the chemical substance sensing element has high sensitivity and excellent responsiveness. For this reason, CNT can be used for expiratory gas sensing that requires a detection lower limit ppm to ppb level. In addition, since it is highly sensitive, the size of the sensing substrate for attaching the sensing target substance can be made relatively small. For the same reason, it can be measured with a small amount of sample gas. The size of the apparatus can be made relatively small. Furthermore, since whether or not gas is detected can be detected by a change in electrical resistance, it is possible to output the detection result of the exhaled gas in an easy-to-operate manner using an already established electrical technique. In addition, CNT is surface-modified, and the substance used for the surface modification is selected according to the chemical substance to be measured so as to selectively bind with a specific chemical substance by its molecular structure and electrical characteristics. The Therefore, the target exhalation gas component can be selectively detected.

  As a result, it is possible to provide a breathing gas sensor device that has a relatively small operating procedure that is compatible with personal use and that is relatively small.

  Preferably, the specific chemical substance is acetone, and the surface-modified carbon nanostructure is surface-modified with an alkyl group (hereinafter referred to as “CH group”). The inventor of the present application has confirmed that the acetone in the sample gas can be detected by the gas sensor device using the CNT surface-modified with the CH group as described above, and the sensitivity thereof is lower than the detection limit of 100 ppb. Acetone is a marker for diabetes. That is, according to this gas sensor device, it is possible to sense acetone in exhaled breath with high sensitivity and high marker selectivity.

  Preferably, the specific chemical substance is pentane, and the carbon nanostructure is surface-modified with a metal complex or a derivative thereof. More preferably, the metal complex is made of metal phthalocyanine (hereinafter referred to as “MePc”).

  The inventor of the present application was able to detect pentane in the sample gas with a gas sensor device using CNT surface-modified with MePc, and confirmed that the sensitivity was below the detection limit of 100 ppb.

  According to the present gas sensor device, sensing of pentane in exhalation can be performed with high sensitivity and high marker selectivity.

  Preferably, the specific chemical substance is nitric oxide, and the carbon nanostructure is surface-modified with a fluorescent molecule that selectively binds to nitric oxide. Preferably, the fluorescent molecule consists of diaminofluorescein-2 (hereinafter referred to as “DAF-2”).

  The inventor of the present application has confirmed that NO in the sample gas can be detected by a gas sensor device using CNT surface-modified with DAF-2, and the sensitivity thereof is not more than a detection lower limit of 100 ppb.

  According to this gas sensor device, sensing of NO in exhaled breath can be performed with high sensitivity and high marker selectivity.

  Preferably, the gas sensor device includes a plurality of chemical substance sensing elements. The plurality of chemical substance sensing elements include carbon nanostructures whose surfaces are modified with substances that selectively adsorb different specific chemical substances. The detection means includes means for individually detecting a change in electrical resistance of the plurality of chemical substance sensing elements.

  Each chemical substance sensing element changes its electrical resistance according to the amount of adsorption of a different specific chemical substance. The detection means individually detects a change in electrical resistance of each chemical substance sensing element. Since each surface modifying material selectively binds to a different marker in expiration, the user can know the sensing result of each marker simultaneously and individually. The operation may be the same as when one chemical substance sensing element is used. Therefore, it is possible to obtain information on a plurality of types of diseases by a single breath measurement by a simple procedure.

  Preferably, the gas sensor device is provided in a space formed inside the housing, and removes the substance adsorbed on the surface of the chemical substance sensing element by heating, irradiating light, or gas flow to the chemical substance sensing element. It further includes a regenerating means for separating.

  According to this apparatus, the substance adsorbed on the surface of the chemical substance sensing element can be removed. For this reason, the gas sensing by this gas sensor apparatus can be performed repeatedly.

  Preferably, the gas sensor device is provided between a first space in which the chemical substance sensing element is provided and a second space other than the first space, and the first space and the first space. Separation means for changing the state between a closed state that separates the two spaces and an open state that communicates the first space and the second space is further included.

  In this gas sensor device, the substance adsorbed on the surface of the chemical substance sensing element is removed by the regeneration means. In this case, if the casing is closed with respect to the outside, the removed substance diffuses into the casing and contaminates the casing inner wall. In the closed state, the separating means separates the space in the housing into a first space in which the chemical substance sensing element is provided and a second space other than that. As a result, in the closed state, the substance removed from the chemical substance sensing element can be prevented from diffusing into the second space, and contamination of the inner wall of the housing can be prevented.

  More preferably, the sample gas introduction means is provided in the housing so as to introduce the sample gas into the first space. The gas sensor device further includes an outside air introduction unit that is provided in the housing and introduces an external gas into the second space.

  When the sample gas is introduced into the first space by the sample gas introduction means with the separation means closed, the sample gas does not immediately contact the chemical substance sensing element. By opening the separation means at the start of measurement, the sample gas comes into contact with the chemical substance sensing element, and the specific chemical substance is adsorbed on the chemical substance sensing element. Adsorption start timing can be set to a desired timing, and measurement can be performed accurately. After the measurement is completed, when the chemical substance sensing element is regenerated, the separation means is closed, so that the chemical substance detached from the element can be prevented from diffusing into the entire space inside the housing. In this state, when an inert gas is introduced into the second space by the outside air introduction means, these gases can be discharged from the second space more quickly than when there is no separation means, and the outside air can be introduced.

  More preferably, the separating means includes a sliding shutter provided inside the housing and provided between the first space and the second space. Contamination of the inner wall of the housing can be prevented with a simple structure called a sliding shutter.

  Preferably, the gas sensor device further includes a stirring unit that is provided in the housing and stirs the gas inside the housing.

  Preferably, the gas sensor device further includes a dehumidifying means provided in association with the sample gas introducing means for dehumidifying the sample gas.

  Preferably, the gas sensor device further includes a dehumidifying means which is provided in association with the outside air introducing means and dehumidifies the external gas.

  In this gas sensor device, when the sample gas and the external gas are introduced into the casing, the dehumidifying means performs dehumidification. This prevents moisture from entering the housing and suppresses moisture adsorption on the surface of the chemical substance sensing element. Moisture is an inhibitor for gas sensing. By removing moisture, high sensitivity and high accuracy can be measured.

  As described above, according to the gas sensor device of the present invention, a specific chemical substance can be measured with a simple operation. The sensing has substance selectivity, high accuracy, and high sensitivity. Furthermore, since it is highly sensitive, the gas sensor device can be miniaturized. By performing exhaled gas sensing using this apparatus, an individual can perform daily health management.

  Hereinafter, an expiration gas sensor device according to an embodiment of the present invention will be described. In the following description and drawings, the same reference numerals and names are assigned to the same components. Their functions are also the same. Therefore, detailed description thereof will not be repeated.

[First Embodiment]
−Configuration−
1A, 1B, and 1C are a plan view, a front view, and a side view, respectively, of an expired gas sensor device 10 according to a first embodiment of the present invention. Of the constituent elements of the exhalation gas sensor device 10 described below, those that are not particularly described are composed of materials that do not leak gas in the range of the operating temperature and do not change or deform. It shall be. Further, the material is assumed to be a material that does not generate gas in the operating temperature range.

  Referring to FIGS. 1A, 1B, and 1C, an expiration gas sensor device 10 includes a front surface 11 and a back surface (the back surface does not appear in FIG. 1), a right side surface 72 (FIG. 1A). And the right side surface in (B), the left side surface (not shown in FIG. 1, but the left side surface in FIGS. 1A and 1B is the left side surface), and the upper surface 13 and the lower surface (FIG. 1 is not shown in FIG. 1), and a breath collection box 12 which is a hollow housing having a rectangular parallelepiped shape. The breath collection box 12 is preferably about 4 to 6 cm long, 16 to 20 cm wide and about 4 to 6 cm deep.

  In the exhalation collection box 12, an opening 16 is formed in the right side surface 72. The opening 16 penetrates the inside and outside of the exhalation collection box 12 and is provided to enable movement of a shutter knob described later.

  The breath gas sensor device 10 further receives a power switch 30 provided on the front surface 11, a measurement switch 32 for receiving a breath sensing start / end instruction, and a CNT gas sensor regeneration start / end instruction to be described later. And a display device 36 for displaying the result of breath sensing, and a calibration button 37 operated when performing a calibration process relating to the measurement of breath sensing.

  The expiratory gas sensor device 10 further includes an expiratory introduction portion 22 for introducing expiratory air into the expiratory collection box 12 and an outdoor air introducing portion for introducing outside air into the expiratory collection box 12 provided on the right side surface 72, respectively. 24, and a shutter, which will be described later, for separating the space inside the breath collection box 12 into a space where the CNT gas sensor is provided and the other portion, and an opening portion for the shutter. 16 includes a shutter knob 26 provided for opening and closing by operating from the outside via 16, and a seal member 64 provided in the opening 16 for closing the opening 16.

  The seal member 64 includes a pair of flexible rubber sides fixed to the upper side and the lower side of the opening portion 16. A base portion of the shutter knob 26 is inserted into a portion where the pair of rubber sides abut, and is connected to an end portion of the internal shutter. For this reason, it is desirable that the base of the shutter knob 26 be as thin as possible. Details of the shutter knob 26, the shutter, and the seal member 64 will be described later.

  The exhalation gas sensor device 10 further includes exhaust parts 28 and 29 provided on the left side surface of the exhalation collection box 12 for exhausting gas and air inside the exhalation collection box 12.

  FIG. 2 shows a cross-sectional view in the direction of the arrow in section 2-2 shown in FIG. 1A, and FIG. 3 shows a cross-sectional view in the direction of the arrow in section 3-3 shown in FIG. 2 and 3 show a case where the shutter is in the open state.

  With reference to FIGS. 2 and 3, openings 14 and 15 are formed on the right side surface 72 of the breath collection box 12 in the vicinity of the upper surface 13 and the lower surface. The opening portion 16 described above is formed in a portion of the right side surface 72 between the opening portions 14 and 15. Openings 18 and 20 are formed in the vicinity of the upper surface 13 and the lower surface of the left side surface, respectively.

  The exhalation introduction part 22 is made of a pipe and is composed of an exhalation introduction member 80 having one end fitted inside the opening 14 and a flexible rubber, and the other end of the exhalation introduction member 80 is detachably covered. And a dehumidifying portion 88 provided in the inner hole of the exhalation introduction member 80 for removing moisture contained in the exhalation. The dehumidifying part 88 is substantially a desiccant and is preferably composed of silica gel or a polymer or both.

  The outside air introduction part 24 is formed of a pipe and has one end fitted into the inside of the opening part 15 from the outside and a flexible rubber, and the other end of the outside air introduction member 82 can be attached and detached. And a dehumidifying portion 89 provided in the inner hole of the outside air introduction member 82 for removing moisture contained in the exhaled breath. The dehumidifying part 89 is also substantially a desiccant and is preferably composed of silica gel or a polymer or both.

  The shutter knob 26 has a base portion provided so as to pass through the abutting portions 70 of the pair of seal members 64, and a knob portion connected to the base portion, and the base portion will be described later in the expiration collection box 12. Connected to the side of the slider of the shutter.

  The exhaust portions 28 and 29 are each formed of a pipe shape, and one end of each of the exhaust portions 28 and 29 is fitted into the opening portions 18 and 20 from the outside, and a flexible rubber. And caps 85 and 87 for removably covering the other end of each. As will be described later, the space inside the exhalation collection box 12 is separated by a shutter into one space portion in which exhalation is introduced and the CNT gas sensor is not provided and the other space portion in which the CNT gas sensor is provided. However, the exhaust portions 28 and 29 are provided at positions where the gas in one and the other space portions is discharged to the outside.

  The exhalation gas sensor device 10 further includes a plurality of agitation devices 44 provided on the upper inner wall of the exhalation collection box 12 for agitating the sample gas introduced into the exhalation collection box 12. The stirring device 44 is a fan that substantially includes a plurality of wings and a rotating shaft that rotatably holds the wings. The passing diameter of the wings of the stirring device 44 is preferably about 1 to 1.5 cm.

  Each of these fans has a plurality of wings. Of the wings, one tip is made of a material having a higher specific gravity than the other wings. These fans are installed so that the plane of rotation of the wings is substantially parallel to the longitudinal direction of the exhalation collection box 12. When the exhalation collection box 12 is held in hand and the entire exhalation collection box 12 is vibrated along its longitudinal direction, the fan is rotated by a rotational moment caused by the difference in wing weight, and the sample gas inside the exhalation collection box 12 is changed. Stirring is performed to obtain a uniform distribution, and the measurement is completed quickly, and the reliability is improved.

  The exhalation gas sensor device 10 further includes a substrate 50 fixed to the bottom inner wall of the exhalation collection box 12, a heat insulating plate 52 provided in contact with the upper surface of the substrate 50, and an inner surface provided on the upper surface of the heat insulating plate 52. And a heating plate 54 having a heater 62. As will be described later, the heating plate 54 is used to desorb a specific chemical substance attached to the sensing unit, which is the center of the sensor, from the sensing unit. Due to this desorption, the sensing unit again acquires the function of detecting the specific chemical substance. The process for restoring the sensing function in this way is called “reproduction”.

  The breath gas sensor device 10 is further provided so as to be in contact with the upper surface of the heating plate 54, and three CNT gas sensors 40a for detecting specific chemical substances in the sample gas introduced into the breath collection box 12 respectively. , 40b, and 40c. These CNT gas sensors 40a, 40b, and 40c include CNT gas sensor elements 132a, 132b, and 132c for adsorbing specific chemical substances in the sample gas, respectively. The three CNT gas sensor elements 132a, 132b, and 132c are for selectively detecting different specific chemical substances, respectively. Details of the CNT gas sensors 40a, 40b, and 40c and the CNT gas sensor elements 132a, 132b, and 134c will be described later. Hereinafter, the CNT gas sensors 40a, 40b, and 40c may be collectively referred to as the CNT gas sensor 40, and the CNT gas sensor elements 132a, 132b, and 134c may be collectively referred to as the CNT gas sensor element 132.

  The exhalation gas sensor device 10 further includes a front part inside the exhalation collection box 12 in order to separate or communicate the inside of the exhalation collection box 12 into a space in which the CNT gas sensor 40 is provided and other spaces. The slide shutter 41 is provided so as to be slidable in the direction of the side and the back side. Although not shown in detail, the shutter 41 has a length substantially the same as the inner diameter in the longitudinal direction inside the expiration collection box 12 and is arranged so that the longitudinal direction coincides with the longitudinal direction of the expiration collection box 12. Combining strip-shaped members in a slender shape, the slider 42 has a structure that can be flexibly bent at least downward from the surface formed by these members, and the slider 42 is slidably held on the front side and the back side. Thus, a pair of slider guides 43 formed on both side surfaces inside the breath collection box 12 and the slider 42 are slid to the back side so that the space provided with the CNT gas sensor 40 communicates with the other spaces. In some cases, a slider storage portion 46 provided on the back side inside the expiration collection box 12 so as to store the slider 42 is included. Of the two sides of the slider 42, the right side 72 side is coupled to the tip of the base of the shutter knob 26. When the shutter knob 26 is slid inside the aperture 16, the slider 42 slides accordingly, and the inside of the breath collection box 12 is separated into a space in which the CNT gas sensor 40 is provided and a space other than that. It is possible to change between a space where the CNT gas sensor 40 is provided and a state where the CNT gas sensor 40 communicates with other spaces.

  In the measurement by the expiration gas sensor device 10, the slider 42 is first closed, and the sample gas is introduced into the expiration collection box 12. Thereafter, the slider 42 is opened, and the sample gas is introduced into the space around the CNT gas sensor 40. Since the slider 42 is for separating the internal space of the exhalation collection box 12 into two parts, the slider 42 may be formed so that there is no gap between the members constituting the slider 42 when the slider 42 is closed. desirable.

  The slider guide 43 is formed at a position corresponding to the opening portion 16 on the right side surface and the left side surface of the inner wall of the exhalation collection box 12, and holds the slider 42 so as to be movable along the slide direction. Is. The slider storage portion 46 is provided continuously to the slider guide 43 so that most of the slider 42 can be stored when the slider 42 is moved to a position where the space inside the breath collection box 12 communicates. In addition, a space is formed on the back side of the inside of the expiration collection box 12 so as to separate the space into an upper part and a lower part. The slider storage portion 46 is formed so as to be bent in a semicircular shape and reach the bottom of the inside of the breath collection box 12, and when the slider 42 is opened, the rear portion of the slider 42 is stored in this portion. Details of the shutter knob 26, slider 42, slider guide 43, and slider storage 46 will be described later.

  4 is a diagram showing a schematic perspective view of the expiration gas sensor device 10 when the slider 42 is in a closed state. FIGS. 5A and 5C are arrows along the line 5A-5A shown in FIG. FIG. 5B is a sectional view taken along the line 5B-5B shown in FIG. 1B and FIG. 5A, and FIG. 5B-5B line shown in FIG. 5 and a 5D-5D line shown in FIG. 5A and 5B show the case where the slider 42 is closed, and FIGS. 5C and 5D show the case where the slider 42 is open.

  4 and 5, only the exhalation collection box 12, the shutter knob 26, the slider 42, the slider guide 43, and the slider storage portion 46 are shown for the purpose of facilitating the understanding of the drawings.

  4 and FIGS. 5A and 5B, when the shutter knob 26 is moved to the end portion 16a on the front surface 11 side of the aperture portion 16, the end surface on the front surface 11 side of the slider 42 is It contacts the inner wall on the front side of the exhalation collection box 12. In this state, the internal space of the exhalation collection box 12 is separated into a space in which the CNT gas sensor 40 is provided and a space other than that by the slider 42 and the slider storage 46.

  5C and 5D, when the shutter knob 26 is moved to the end 16b on the back side of the opening portion 16, the back side portion of the slider 42 is inside the slider storage portion 46. It is stored in. In this state, the two spaces separated by the slider 42 in the expiration collection box 12 communicate with each other.

  As can be seen from FIG. 2, the exhalation introduction unit 22 is formed at a position that introduces exhalation into a space portion where the CNT gas sensor 40 is not provided in the space inside the exhalation collection box 12. On the other hand, the outside air introduction part 24 is formed at a position where outside air is introduced into the space where the CNT gas sensor 40 is provided in the space inside the expiration collection box 12. The exhaled air introduced into the exhalation collection box 12 from the exhalation introducing unit 22 with the shutter 41 closed comes into contact with the CNT gas sensor element 132 by opening the shutter 41.

  FIG. 6 is a schematic block diagram for explaining the configuration of an electric circuit for obtaining the output of the exhalation gas sensor device 10. In FIG. 6, a thick arrow indicates a power line, and a thin arrow indicates a signal line. Referring to FIG. 6, the breath gas sensor device 10 controls a power switch 30 for controlling power supply from the power source described later to the display conversion device 112 and the display device 36, and power supply from the power source to the CNT gas sensor 40. In addition to the measurement switch 32, the regeneration switch 34 for controlling the power supply from the power source to the heating plate 54, the display device 36, the calibration button 37, the CNT gas sensor 40, and the heating plate 54, the output of the CNT gas sensor 40 is A display conversion device 112 for conversion to display on the display device 36 and a power source 110 for supplying power to these are included.

  The display conversion device 112 operates by receiving power supply from the power supply 110 and is connected so as to receive the output of the CNT gas sensor 40 and the output of the calibration button 37, and the CNT gas sensor when the calibration button 37 is pressed. The output value of 40 is set as a zero point, and the change amount of the output voltage of the CNT gas sensor 40 with respect to the zero point is converted into a signal that can be displayed on the display device 36 as the concentration of the specific chemical substance to be measured and output. Is. In the present embodiment, the display conversion device 112 stores a correspondence table prepared in advance for the amount of change in voltage applied from the three CNT gas sensors 40 and the concentration of the three specific chemical substances corresponding thereto. It is assumed that the concentrations of these specific chemical substances are calculated by table lookup based on the input voltage change.

  FIG. 7 shows a schematic block diagram of the CNT gas sensor 40. Referring to FIG. 7, CNT gas sensor 40 includes DC power supply 130 that receives power supply from power supply 110 shown in FIG. 6, CNT gas sensor element 132 having one end connected to the positive terminal of DC power supply 130, and CNT gas sensor element. A load resistor 134 connected between the other end of 132 and the negative terminal of the DC power supply 130, and an input connected to the contact point of the CNT gas sensor element 132 and the load resistor 134, and for amplifying the potential change of the contact point. Amplifier 136 and a detecting device 138 for detecting this potential change. The output of the detection device 138 is connected to the input of the display conversion device 112 shown in FIG.

  FIG. 8 shows a plan view of the CNT gas sensor element 132. Referring to FIG. 8, a CNT gas sensor element 132 is produced in a plate shape on a substrate 162, and a sensing unit 160 made of CNT for adsorbing and detecting a specific chemical substance in a sample gas. And silver pastes 164 and 166 formed on the substrate 162 and connected to both ends of the sensing unit 160, respectively, and provided on the substrate 162 to be connected to the silver pastes 164 and 166, respectively. And electrodes 168 and 170 for outputting a potential difference to the outside. The electrode 168 is connected to the plus terminal of the DC power supply 130 shown in FIG. The electrode 170 is connected to the load resistor 134 and the amplifier 136 shown in FIG.

  Here, it is assumed that the three sensing units 160 (160a, 160b, and 160c) selectively adsorb pentane, NO, and acetone, respectively. As will be described later, the sensing unit 160a is formed by a CH group and MePc. The sensing unit 160b includes surface-modified CNT, and the sensing unit 160c includes CNT surface-modified with a CH group. The sensing unit 160c includes CNT surface-modified with a CH group. Hereinafter, the sensing units 160a, 160b, and 160c may be collectively referred to as the sensing unit 160.

  MePc, fluorescent molecules, and CH groups have the ability to react only with specific chemical substances, and the three sensing units 160 each adsorb different specific chemical substances in the atmosphere. The resistance value of the sensing unit 160 when a current is passed through the sensing unit 160 varies depending on whether or not a substance is adsorbed on the sensing unit 160. Therefore, different specific chemical substances in the atmosphere can be selectively detected by the CNT gas sensor 40 shown in FIG. That is, by introducing exhaled air around the CNT gas sensor 40 and measuring the output of the amplifier 136 with the detection device 138, a specific chemical substance in the exhaled gas can be selectively detected.

-Manufacturing method of first sensing unit 160a-
The first sensing unit 160a is manufactured as follows.

  Commercially available dispersed CNT (liquid in which CNT is dispersed) is put into an ethanol solution prepared in a container. The container is irradiated with ultrasonic waves by an ultrasonic generator. In the container, the CNTs are uniformly separated and dispersed in the ethanol solution. The CNT dispersion obtained in the above step is suction filtered using a filter folder. Thereafter, the filter and the CNTs on the filter are left to evaporate ethanol. The filter is cut to an appropriate size. A MePc solution diluted in advance to the CNT of the cut filter is dropped and adhered to the CNT surface. Thereby, the 1st sensing part 160a containing CNT surface-modified by CH group and MePc is obtained.

-Manufacturing method of second sensing unit 160b-
The second sensing unit 160b is manufactured in the same manner as the sensing unit 160a. However, instead of the MePc solution, the surface modification of the CNT is performed using a fluorescent molecule solution having a selective ability to react only with a specific chemical substance to be detected, such as DAF-2. As a result, the second sensing unit 160b including the CNT surface-modified with the CH group and the fluorescent molecule is obtained.

-Manufacturing method of third sensing unit 160c-
The third sensing unit 160c is manufactured in the same manner as the first sensing unit 160a. However, the MePc solution is not dropped on the CNT of the cut filter. Thereby, the 3rd sensing part 160a containing CNT by which CH group was modified on the surface is obtained.

-Operation-
<Procedure for Exhalation Gas Sensing by Exhalation Gas Sensor Device 10>
Hereinafter, the operation procedure of the expiration gas sensor device 10 and the operation of the expiration gas sensor device 10 in each procedure will be described. Here, it is assumed that the sensing unit 160 included in the expired gas sensor device 10 has been newly created or has been regenerated. Further, it is assumed that the slider 42 is in an open state. At this time, as shown in FIG. 5A, the shutter knob 26 is set to the end portion 16b on the back side of the aperture portion 16.

  FIG. 9 is a diagram for explaining a method of measuring exhalation by the exhalation gas sensor device 10. Referring to FIGS. 2 and 9, the caps 85 and 87 of the exhaust parts 28 and 29 are removed so that the gas in the exhalation collection box 12 can be exhausted from the exhaust port members 84 and 86. The cap 81 of the exhalation introduction unit 22 is removed, and the sample gas is introduced from the exhalation introduction member 80. Due to the sample gas introduced from the exhalation introduction member 80, the inside of the exhalation collection box 12 becomes a positive pressure, and the gas sealed in the exhalation collection box 12 is exhausted to the outside. When the sample gas is introduced, the moisture of the sample gas is removed by the dehumidifying unit 88.

  Thereafter, the cap 81, 85 and 87 close the exhalation introduction member 80 and the exhaust port members 84 and 86, thereby holding the sample gas in the exhalation collection box 12.

  As shown in FIG. 10, the breath gas sensor device 10 is held and vibrated along its longitudinal direction for the purpose of making the component distribution of the sample gas constant.

  At this time, in the breath collection box 12, the stirring device 44 shown in FIGS. 2 and 3 rotates due to the rotational moment of the wing caused by the difference in wing mass. As a result, the exhaled air enclosed in the exhalation collection box 12 is agitated by the rotating wings, and the distribution of gas components in the exhalation becomes more uniform. Here, the vibration work is continued for 5 minutes, and then the exhalation collection box 12 is left to stand in a horizontal place for 1 minute. After standing for 1 minute, the power switch 30 is turned on.

  6 and 7, power is supplied to the display conversion device 112 and the display device 36, and the display device 36 displays an initial screen.

  Thereafter, the measurement switch 32 is turned on. Each of the three CNT gas sensors 40 operates as follows. Power is supplied from the power source 110 to the DC power source 130. The DC power source 130 applies a constant voltage to both ends of a CNT gas sensor element 132 and a load resistor 134 connected in series. Referring to FIG. 8, when a specific chemical substance in the sample gas adheres to the surface of CNT constituting sensing unit 160, the electrical resistance between electrodes 168 and 170 changes. The change is detected by the detection device 138 as a change in the output voltage of the amplifier 136.

  As described above, the specific chemical substance is adsorbed to each sensing unit 160 due to the selectivity of the surface modification material of CNT to the adsorbed substance. The amount is considered to be proportional to the concentration of the specific chemical substance in the sample gas. As a result, the concentration of the specific chemical substance in the sample gas is detected as an output voltage change in the CNT gas sensor element 132.

  The modified MePc, fluorescent molecule, and CH group on the CNT surfaces of the three sensing units 160 selectively adsorb different specific chemical substances. Therefore, by knowing the amount of change in electrical resistance for each of the three CNT gas sensor elements 132, the presence or absence and concentration of these specific chemical substances in exhaled breath can be confirmed.

  The output voltage change detected by the detection device 138 is output to the display conversion device 112. Here, the output voltage change and the specific chemical substance concentration are specifically calculated and measured as follows. An inert gas that is not adsorbed by the sensing unit 160 or the like is used as a calibration gas, and the output voltage is detected in advance by the detection device 138 by the same operation as when detecting a specific chemical substance. At this time, by pressing the calibration button 37, the display conversion device 112 sets the output voltage to the zero point. Thereafter, the measurement switch 32 is turned off. The sample gas is introduced into the exhalation collection box 12 and the above operation is performed, and the measurement switch 32 is turned on. The detection device 138 and the like detect an output voltage with respect to the sample gas. The display conversion device 112 calculates a difference (output voltage change) between the input output voltage and the zero point. The display conversion device 112 further calculates the concentration of the specific chemical substance by looking up from the correspondence table using the calculated output voltage change as a key. In accordance with the calculated concentration of the specific chemical substance, the display conversion device 112 outputs a signal that can be displayed on the display device 36 after the signal conversion processing. For example, each concentration of pentane, NO, and acetone is displayed on the display device 36 in ppb units.

  After the concentration of the specific chemical substance is confirmed by the display device 36, the power switch 30 and the measurement switch 32 are turned off to complete the measurement.

<Reproduction procedure of sensing unit 160>
Hereinafter, an operation procedure for regeneration of the sensing unit 160 and the operation of the breath gas sensor device 10 in each procedure will be described.

  With reference to FIG. 2, the shutter knob 26 is moved to the end portion 16a on the front surface 11 side of the aperture portion 16 shown in FIG. In the exhalation collection box 12, the peripheral part of the CNT gas sensor 40 and another space are separated.

  After the regeneration switch 34 is turned on, the cap 87 is removed, and exhaust from the exhaust port member 86 is enabled. In this state, the breath gas sensor device 10 is vibrated in the same manner as the stirring process shown in FIG. Electric power is supplied to the heating plate 54 and heating by the heater 62 is started. When the sensing unit 160 reaches 50 ° C. to 70 ° C. due to the heating of the heating plate 54, the specific chemical substance adsorbed on the sensing unit 160 is desorbed. The desorbed substance tends to rise due to the convection action of the gas, but this is suppressed by the slider 42. For this reason, the detached substance does not diffuse over the entire inner wall of the exhalation collection box 12. The gas around the CNT gas sensor 40 expands due to the heating, and moves from the exhaust port member 86 to the outside of the exhalation collection box 12.

  5 minutes after the regeneration switch 34 is turned on, the regeneration switch 34 is turned off. The heater 62 stops heating.

  The cap 83 is removed, and an inert gas is immediately introduced from the outside air introduction member 82 into the expiration collection box 12. At this time, moisture is removed from the inert gas by the dehumidifying unit 89. By introducing the inert gas, the peripheral portion of the CNT gas sensor 40 separated by the slider 42 becomes positive pressure, and the gas in the peripheral portion of the CNT gas sensor 40 is further discharged from the exhaust port member 86 to the outside. This operation is continued until the inert gas introduced into the exhalation collection box 12 from the outside air introduction member 82 is discharged to the outside from the exhaust port member 86. Thereafter, the outside air introduction member 82 and the exhaust port member 86 are closed by the caps 83 and 87.

  By the above operation, the substance detached from the sensing unit 160 by the regeneration is discharged to the outside without contaminating the inside of the expiration collection box 12. An inert gas is introduced into the periphery of the CNT gas sensor 40. For this reason, the sensing unit 160 can maintain a clean state until the next breath gas sensing.

[Example]
Examples based on the first embodiment will be described below.

-Manufacturing method of CNT gas sensor element 132a-
The CNT gas sensor element 132a was manufactured by the method described below.

  A method for manufacturing the first sensing unit 160a will be described below. First, CH group modification of CNT was performed. Dispersed CNT (manufactured by Ena Co., Ltd.) was put into an ethanol solution prepared in a beaker, and then this beaker was placed in a 10 kHz, 8 W ultrasonic cleaner, and the sample in the beaker was irradiated with ultrasonic waves. This was done until dispersed throughout the solution. After the dispersion, the ethanol solution containing the dispersed CNTs was subjected to suction filtration with a filter folder and a filter bell equipped with a PTFE (Polytetrafluoroethylene) membrane filter (manufactured by Millipore; hereinafter simply referred to as “filter”) having a hole diameter of 0.2 μm. . In order to volatilize ethanol, the CNT remaining on the filter was allowed to stand for 3 hours together with the filter to obtain CNT modified with CH groups. After standing, the filter was cut to a size of 2 cm × 0.7 cm.

  Next, surface modification with a metal complex of CNT was performed. Cu phthalocyanine (manufactured by Tokyo Chemical Industry) was dissolved in tetrahydrofuran (THF) to prepare a 0.1 mM Cu phthalocyanine solution. Then, 5 microliters of Cu phthalocyanine solution was dropped onto the surface of the carbon nanostructure on the filter after cutting with a pipette. The flat sample obtained as described above was used as the first sensing unit 160a.

  Referring to FIG. 8, first sensing unit 160 a is installed on substrate 162 made of an insulating material, and is connected to substrate 162 by silver pastes 164 and 166. Furthermore, 0.5 mmφ gold fine wires were connected by the same silver pastes 164 and 166, which were used as electrodes 168 and 170, and the manufacture of the CNT gas sensor element 132a was completed. The manufactured CNT gas sensor element 132a was introduced into the breath gas sensor device 10.

-Manufacturing method of CNT gas sensor element 132b-
A method for manufacturing the second sensing unit 160b will be described below. First, the CH group modification of CNT was performed in the same manner as the manufacturing method of the first sensing unit 160a. Next, surface modification of CNT with DAF-2 was performed. Dimethylsulfoxide (hereinafter referred to as “DMSO”) 550 μL of 1 mg of DAF-2 developed in 1 mg of DAF-2 was diluted 500-fold with phosphate buffer (0.1 mol / L) (about approx. 10 μmol / L). 10 μL of this solution was dropped onto the CNT surface on the membrane filter after cutting with a pipette. The flat sample obtained as described above was used as the second sensing unit 160b. Subsequent processing is the same as that of the CNT gas sensor element 132a.

-Manufacturing method of CNT gas sensor element 132c-
The manufacturing method of the third sensing unit 160c is the same as the CH group modification of CNT in the manufacturing method of the first sensing unit 160a. The flat sample obtained as described above was used as the third sensing unit 160c. Subsequent processing is the same as that of the CNT gas sensor element 132a.

-Evaluation method (1) Pentane concentration-
A method for evaluating the characteristics of the CNT gas sensor element 132 will be described below. The breath gas sensor device 10 shown in FIG. 1 was placed on a flat place. The slider 42 was opened. The cap 81 shown in FIG. 2 was removed, and a Tedlar bag filled with nitrogen gas as a calibration gas was connected to the breath introduction member 80. A pressure was applied to the Tedlar bag from the outside, and nitrogen gas was introduced into the breath collection box 12. At the same time, the caps 85 and 87 were removed, and the gas already enclosed in the exhalation collection box 12 was exhausted through the exhaust port members 84 and 86. When the Tedlar back was deflated, the exhaust ports 84 and 86 were fitted with caps 85 and 87 to stop the exhaust. Next, the Tedlar bag was removed from the exhalation introduction member 80, and the cap 81 was immediately put on the exhalation introduction member 80 to close the exhalation introduction member 80. After the above-described stirring operation was performed for 5 minutes, the expired gas sensor device 10 was allowed to stand on a flat place.

  The power switch 30 and the measurement switch 32 were turned on. Here, in the CNT gas sensor 40a, the current passed by the DC power supply 130 was 200 μA, and the initial resistance of the CNT gas sensor element 132a was Ro = 20 kΩ. The detection frequency of the detection device 138 is 1 second, and the average output voltage of the CNT gas sensor element 132a detected within 60 seconds is output to the display conversion device 112. Other CNT gas sensors were also measured under the same conditions. By pressing the calibration button 37 shown in FIG. 1, the input value is set as an initial value in the display conversion device 112. Thereafter, the pressing of the calibration button 37 was stopped, and the measurement switch 32 was turned off.

  Next, the sensing object gas having a pentane concentration of 100 ppb enclosed in the Tedlar bag was introduced into the exhalation collection box 12 in the same manner as when nitrogen gas was enclosed. When the Tedlar back was deflated, the exhaust ports 84 and 86 were fitted with caps 85 and 87 to stop the exhaust. Next, the Tedlar bag was removed from the exhalation introduction member 80, and the cap 81 was immediately put on the exhalation introduction member 80 to close the exhalation introduction member 80.

  The sensing gas was produced as follows. The pentane standard gas diluted with nitrogen to a concentration of 1 ppm and nitrogen gas were mixed at a ratio of 1: 9 to dilute the pentane standard gas to obtain a sensing target gas having a pentane concentration of 100 ppb.

  After stirring for 5 minutes, the breath gas sensor device 10 was allowed to stand on a flat surface. In this state, the measurement switch 32 was turned on, and the pentane, NO, and acetone concentrations displayed on the display device 36 were confirmed.

-Evaluation method (2) NO concentration-
By the method similar to the evaluation method (1), the gas to be sensed including NO by the expired gas sensor device 10 was measured. The method for creating the sensing target gas was the same as in the evaluation method (1), and NO was used instead of pentane.

-Evaluation method (3) Acetone concentration-
By the method similar to the evaluation method (1), the gas to be sensed containing acetone was measured by the breath gas sensor device 10. The method for producing the sensing target gas was the same as in the evaluation method (1), and acetone was used instead of pentane.

-Evaluation method (4) Concentration of pentane, NO and acetone-
The sensing target gas containing pentane, NO, and acetone was measured by the breath gas sensor device 10 by the same method as the evaluation method (1). The sensing gas was produced as follows. Pentane standard gas diluted with nitrogen to a concentration of 1 ppm, NO standard gas diluted in the same manner as pentane standard gas, and acetone standard gas are prepared in equal amounts and mixed. By mixing this mixed gas and nitrogen gas at a ratio of 3: 7, a sensing target gas having a pentane concentration of 100 ppb, an NO concentration of 100 ppb, and an acetone concentration of 100 ppb was obtained.

-Evaluation method (5) Regeneration processing-
After the experiment of the evaluation method (4), the power switch 30 and the measurement switch 32 were turned off and the slider 42 was closed. The regeneration switch 34 was turned on, the cap 87 was removed, and the gas in the exhalation collection box 12 was exhausted from the exhaust port member 86. After 5 minutes, the regeneration switch 34 was turned off. The cap 83 was removed, and a Tedlar back filled with nitrogen gas was connected to the outside air introduction member 82. A pressure was applied to the Tedlar bag from the outside, and nitrogen gas was introduced into the exhalation collection box 12. When the tedlar back was deflated, the tedlar back was removed from the outside air introduction member 82, and the outside air introduction member 82 and the exhaust port member 86 were immediately closed by the caps 83 and 87.

  Here, after the same stirring operation as in the evaluation method (1) was performed, the power switch 30 and the measurement switch 32 were turned on, and the concentrations of pentane, NO, and acetone displayed on the display device 36 were confirmed.

-Evaluation results-
In the evaluation method (1), the display device 36 displayed pentane 98 ppb, NO 0 ppb, and acetone 0 ppb.

  In the evaluation method (2), the display device 36 displayed pentane 0 ppb, NO 100 ppb, and acetone 0 ppb.

  In the evaluation method (3), the display device 36 displayed pentane 1 ppb, NO 0 ppb, and acetone 100 ppb.

  In the evaluation method (4), the display device 36 displayed pentane 99 ppb, NO 101 ppb, and acetone 102 ppb.

  In the evaluation method (5), the display device 36 displayed pentane 0 ppb, NO 0 ppb, and acetone 0 ppb.

  From the above results, it was found that this breath gas sensor device can confirm the presence of pentane, NO, and acetone, and the detection lower limit thereof is 100 ppb or less, respectively. Furthermore, even if these specific chemical substances were mixed, it was possible to detect at a level of 100 ppb, and it was confirmed that a plurality of types of exhalation markers could be detected by a single measurement. Furthermore, after the regeneration process, the concentration of each specific chemical substance showed a zero level, and almost no change in electrical resistance in the sensing unit 160 or the like was observed. From this, it was found that the substance adsorbed on the sensing unit 160 and the like was removed by the regeneration process.

  As described above, according to the present gas sensor device, it is possible to carry out a plurality of specific chemical substances with a single measurement. The sensing has substance selectivity, high accuracy, and high sensitivity. When sensing exhalation, by including a plurality of types of chemical substance sensing elements, for example, information on a plurality of diseases such as diabetes, lifestyle-related diseases, and respiratory diseases can be obtained.

  When exhalation is introduced into the device and the button is pressed, the concentration of a specific chemical is displayed. Information can be obtained by such a simple operation. Furthermore, because of the high sensitivity, the breath collection box of the sensing substrate and device can be made smaller. From these facts, it can be said that the present apparatus can be effectively used as a method for daily health management by an individual.

  In particular, it can be said that the provision of the slider 42 is unlikely to degrade the measurement performance even if measurement and reproduction are repeated.

[Modification]
In the above embodiment, MePc is used as the metal complex. However, in the present invention, the metal complex is not limited to this. Any general metal complex or derivative thereof can be used as long as it can be surface-modified to CNT as described above and has substance selectivity with respect to an adsorbed substance.

  In the present invention, the surface modification material of CNT in the manufacturing method of the first sensing unit 160a is not limited to Cu phthalocyanine. Co phthalocyanine, Ni phthalocyanine, Fe phthalocyanine, porphyrin, and the like may be used.

  In the above embodiment, there are a plurality of CNT gas sensors, each detecting a different specific chemical substance, and the concentration calculated individually based on the change in each output voltage is individually displayed. However, the present invention is not limited to such an embodiment. For example, the concentration ratio between the reference substance and the marker may be calculated by using two CNT gas sensors, and a display may be made so that the marker concentration level can be understood based on the concentration ratio. That is, the marker concentration may be normalized by the concentration of the reference substance.

  Specific examples are shown below. The exhaled gas sensor device includes a first CNT gas sensor for detecting a component contained in exhaled gas at a high ratio, and a second CNT gas sensor for detecting a marker contained in a trace amount. The level of the marker concentration ratio (hereinafter referred to as “concentration ratio”) with respect to the concentration of the component contained in the exhalation at a high ratio is divided in advance. For example, there are three levels from low to high, each with a numerical range of the average concentration ratio in the breath of a healthy person, a numerical range of the average concentration ratio of a person with respiratory disease, and It is assumed that the numerical value range is between the two. The display conversion device stores information necessary for the level division in advance. The display conversion device calculates the concentration ratio based on the input signals from the first and second gas sensors, determines which of the above three levels the concentration ratio corresponds to, and outputs a signal to the display device based on the determination result. To do. The display device displays, for example, green if the concentration ratio is equivalent to the breath of a healthy person, red if it is equivalent to the person who has developed symptoms, and yellow if it is between the two. Even in this case, the user can check his / her health condition (in this case, related to respiratory disease).

  In addition to the first and second CNT gas sensors, the exhalation gas sensor device may further include another two pairs of integrated CNT gas sensors. Among these other sensors, the marker detection sensor detects a marker different from the other marker detection sensors. As a result, it is possible to confirm the concentration levels of a plurality of types of markers by a single measurement.

  In the above embodiment, the heating plate 54 includes the heater 62, and the adsorbed material is removed by heating the sensing unit. However, the present invention is not limited to such an embodiment. For example, the reproduction device may be a visible light LED (Light Emitting Diode), and the adsorbed substance may be removed by irradiating the sensing unit with a visible light of 1 mW for a predetermined time. As another example, the regeneration device may be a device for performing gas flow. In this case, for example, referring to FIG. 2, in the expired gas sensor device 10, the slider 42 is closed and the exhaust unit 29 is opened (the cap 87 is removed). An inert gas is injected from the outside air introduction unit 24 at a specific pressure by the regenerator for a predetermined time. When the gas flows in the direction from the outside air introduction unit 24 to the exhaust unit 29, the substance adsorbed on the sensing unit is desorbed and exhausted outside the housing 12.

  In the above embodiment, the desiccant for removing moisture from the exhaled air and the outside air introduced into the exhalation collection box 12 is provided inside the exhalation introducing unit 22 and the outside air introducing unit 24. However, the present invention is not limited to such an embodiment, and what is used is any one as long as moisture is removed from the breath collection box 12 before breath or outside air is introduced into the breath collection box 12. You may provide in a position. For example, a cartridge-type mouthpiece may be connected to the end of the exhalation introduction unit 22 and the outside air introduction unit 24 that are not connected to the exhalation collection box 12, and a desiccant may be provided therein.

  The embodiment disclosed herein is merely an example, and the present invention is not limited to the above-described embodiment. The scope of the present invention is indicated by each claim in the claims after taking into account the description of the detailed description of the invention, and all modifications within the meaning and scope equivalent to the wording described therein are intended. Including.

It is a 3rd page figure of exhalation gas sensor device 10 concerning a 1st embodiment of the present invention. It is arrow direction sectional drawing of the expiration gas sensor apparatus 10 in the cross section 2-2 shown to FIG. 1 (A). FIG. 3 is a cross-sectional view in the direction of the arrows of the breath gas sensor device 10 in a cross section 3-3 shown in FIG. 1 is a perspective view of an exhalation gas sensor device 10. FIG. FIG. 5 is a schematic cross-sectional view in the direction of the arrows of the breath gas sensor device 10 at cross sections 5A-5A and 5B-5B shown in FIG. 3 is a schematic block diagram for explaining a power line and a signal line of the expired gas sensor device 10. FIG. 2 is a configuration diagram of a CNT gas sensor 40. FIG. 3 is a configuration diagram of a CNT gas sensor element 132. FIG. It is a figure for demonstrating the method to measure the specific chemical substance in the expiration by the expiration gas sensor apparatus. It is a figure for demonstrating the method to stir the sample gas in the exhalation collection box.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exhalation gas sensor apparatus 12 Exhalation collection box 22 Exhalation introduction part 24 Outside air introduction part 26 Shutter knob 28, 29 Exhaust part 80, 82 Introduction member 81, 83, 85, 87 Cap 84, 86 Exhaust port member 30, 32, 34 Switch 36 Display device 37 Calibration button 40 CNT gas sensor 41 Shutter 42 Slider 43 Slider guide 44 Stirrer 46 Slider storage 50, 162 Substrate 52 Heat insulation plate 54 Heating plate 62 Heater 64 Seal member 112 Display conversion device 130 DC power supply 132 CNT gas sensor element 134 Load Resistance 136 Amplifier 138 Detection device 160 Sensing unit 164, 166 Silver paste 168, 170 Electrode

Claims (15)

A housing in which a space is formed;
A sample gas introduction means provided in the housing for introducing a sample gas into the space of the housing;
A chemical substance sensing element that is provided in the housing and changes its electrical resistance by adsorbing a specific chemical substance in the atmosphere; and
A detection means electrically coupled to the chemical substance sensing element for detecting a change in electrical resistance of the chemical substance sensing element;
An exhaust means provided in the housing for exhausting the gas inside the space to the outside of the housing;
The chemical substance sensing element includes a carbon nanostructure that is surface-modified with a substance selected corresponding to the specific chemical substance.   The gas sensor device according to claim 1, wherein the carbon nanostructure includes a carbon nanotube that is surface-modified with the substance.   The gas sensor device according to claim 1, wherein the specific chemical substance is acetone, and the substance is an alkyl group.   The gas sensor device according to claim 1, wherein the specific chemical substance is pentane, and the carbon nanostructure is surface-modified with a metal complex or a derivative thereof.   The gas sensor device according to claim 4, wherein the metal complex is made of metal phthalocyanine.   The gas sensor device according to claim 1 or 2, wherein the specific chemical substance is nitric oxide, and the carbon nanostructure is surface-modified with a fluorescent molecule that selectively binds to nitric oxide. The fluorescent molecule is diaminofluorescein-2 (Diaminofluorescein).
-2). The gas sensor device according to claim 6, comprising: A plurality of chemical substance sensing elements, wherein the plurality of chemical substance sensing elements include carbon nanostructures that are surface-modified with substances that selectively adsorb different specific chemical substances;
The gas sensor device according to claim 1, wherein the detection unit includes a unit for individually detecting a change in each electric resistance of the plurality of chemical substance sensing elements.   A regenerator provided in the space of the housing, for desorbing the substance adsorbed on the sensing element surface by heating, irradiating light, or gas flow to the chemical substance sensing element; The gas sensor device according to any one of claims 1 to 8.   Of the space inside the housing, the space is provided between the first space in which the chemical substance sensing element is provided and the other second space, and the first space and the second space. The separation means for changing a state between the closed state which isolate | separates a space, and the open state which connects the said 1st space and the said 2nd space is further included in any one of Claim 9 Gas sensor device. The sample gas introduction means is provided in the housing so as to introduce the sample gas into the first space,
The gas sensor device according to claim 10, further comprising an outside air introduction unit that is provided in the housing and introduces an external gas into the second space.   The gas sensor device according to claim 11, wherein the separation unit includes a sliding shutter provided inside the housing and provided between the first space and the second space.   The gas sensor device according to any one of claims 1 to 12, further comprising a stirring unit that is provided in the housing and stirs the gas inside the housing.   Furthermore, the gas sensor apparatus in any one of Claims 1-13 including the dehumidification means provided in relation to the said sample gas introduction means for performing dehumidification of sample gas. Furthermore, the gas sensor apparatus in any one of Claims 1-14 provided in relation to the said external air introduction means and including the dehumidification means for performing dehumidification of external gas.

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