JPWO2007083350A1 - Breath component testing device - Google Patents

Abstract

  It is possible to perform accurate measurement without problems even when measuring low concentration exhalation after continuous measurement or high concentration exhalation, and it is also possible to have a blowing interruption detection function, and Provided is an exhaled breath component inspection device having a high sensitivity response. This expiratory component testing device is provided with an expiratory flow path pipe for blowing in and passing expiratory flow, an expiratory flow introduction hole formed in the midway of the expiratory flow path pipe, and an expiratory flow introduction hole on the outer peripheral surface of the expiratory flow path pipe. A cylindrical sensor housing wall extending from the surrounding portion, a gas sensor fitted into the sensor housing wall to detect a predetermined gas component in exhalation, a gas sensor fitted into the sensor housing wall, and exhalation introduction An expiratory pool space formed between the vent hole, a ventilation hole formed in the sensor housing wall at a position communicating with the expiratory pool space, and a concentration of a predetermined gas component contained in the expiratory gas by driving the gas sensor. Drive measuring means for measuring

Description

  The present invention relates to a breath component inspection device for measuring the concentration of breath component gas such as alcohol and breath contained in breath.

  BACKGROUND ART Conventionally, as disclosed in, for example, Japanese Patent Laid-Open No. 2001-337064, there is known a breath component inspection device used for an application such as measuring alcohol concentration in exhaled breath to inspect drunkenness caused by drinking alcohol. There is. The above-mentioned conventional breath component inspection device is one in which a blow port is formed in the main body case that houses the gas sensor, and the user blows the breath toward the blow port and introduces it into the main body case through the blow port. The structure is such that the exhaled breath comes into contact with the gas sensor and the concentration of the exhaled breath component is measured.

  In such an exhaled breath component inspection device, if the exhaled air blown from the user directly hits the gas sensor, the sensor element of the gas sensor is rapidly cooled, which makes accurate measurement difficult. Will end up. In order to prevent the sensor element from being cooled, the conventional breath component inspection device employs a structure in which the distance from the gas inlet to the gas sensor is large or a structure in which a flow path is complicatedly provided. However, when such a structure is adopted, there are problems that the sensitivity response of the gas sensor becomes slow, and that a space for collecting exhaled air is formed around the gas sensor to make ventilation difficult.

  In particular, if there is a problem with ventilation around the gas sensor, when performing continuous measurement without time, or after measuring the exhaled breath containing the exhaled breath component to be detected at high concentration, try to measure the exhaled breath containing the exhaled breath component at low concentration. In such a case, the exhaled breath component at the time of the previous measurement is trapped around the gas sensor, which makes it difficult to perform the next measurement accurately.

  In addition, the breath component testing device has a problem that it is difficult to provide a function of detecting the interruption of blowing because the ventilation rate around the gas sensor is slow. The blowing interruption detection function here is to detect the interruption of the exhalation by the user during the measurement and stop the measurement, and even if the blowing of the user is stopped midway. Regardless, when the measurement result is output without the detection of the blowing interruption, a density value lower than the original density is displayed. A means of arranging a pressure sensor or the like to monitor the exhalation pressure in order to detect the interruption of the insufflation is conceivable, but in this case, there is a disadvantage in terms of cost, and the structure is complicated and a space for exhalation is provided. It makes it difficult to measure accurately. Therefore, it is preferable to capture the interruption of blowing by the output of the gas sensor, but it is difficult to capture this if the ventilation rate around the gas sensor is slow.

  The present invention has been made in view of the above problems, and it is possible to perform accurate measurement without problems even when continuously measuring or measuring low concentration exhalation after measuring high concentration exhalation. It is an object of the present invention to provide an exhaled breath component inspection device which is capable of providing a blowing interruption detection function and has a high sensitivity response.

  That is, in order to solve the above problems, the expiratory component testing device of the present invention, an expiratory flow passage pipe for blowing in and passing exhaled breath, an expiratory gas introduction hole formed in the midway of the expiratory flow passage pipe, and exhaled breath A cylindrical sensor accommodating wall extending from a portion surrounding the exhalation introducing hole on the outer peripheral surface of the flow path pipe, a gas sensor fitted in the sensor accommodating wall to detect a predetermined gas component in exhalation, and a sensor accommodating wall The expiratory pool space formed between the gas sensor and the expiratory gas introduction hole in the inside, the ventilation hole formed in the sensor housing wall at a position communicating with the expiratory pool space, and the gas sensor are driven. Drive measuring means for measuring the concentration of a predetermined gas component contained in the exhaled air.

  In the exhaled breath component inspection device having the above configuration, the exhaled breath blown into the expiratory flow passage pipe is quickly sent to a position near the gas sensor through the expiratory flow passage pipe, and then in the vicinity of the midway of this flow passage. At the position, it is sent into the expiratory pool space through the expiratory gas introduction hole, and once introduced into the expiratory pool space, is introduced into the gas sensor. The flow rate of the exhaled gas introduced to the gas sensor is limited by the exhaled gas introduction hole, and the pressure of the exhaled air sent to the gas sensor is limited by the ventilation hole, so that the flow rate and pressure at which the user blows the exhaled air do not affect the accuracy. Various measurements can be performed. In addition, fast sensitivity response is also secured.

  Here, the expiratory pool space is configured to exist for a short distance between the flow channel in the expiratory flow channel pipe and the gas sensor, and in addition, the ventilation hole of the sensor housing wall communicates with this expiratory pool space. And ventilation is easy. Therefore, since the ventilation around the gas sensor is very good, it is possible to perform accurate measurement without any problems even when performing continuous measurement or measuring high-concentration breath and then low-concentration breath. It is also possible to provide a blowing interruption detection function.

  It is also preferable that the ventilation hole is a slit-shaped hole that is recessed from the front edge of the sensor housing wall. The tip of the slit-shaped ventilation hole is a portion that communicates with the expiratory pool space.

  In the gas sensor, a sensor element is arranged in a sensor cover formed by opening an intake port toward the expiratory flow path pipe side, and the expiratory gas introduction hole of the expiratory flow path pipe is the intake of the sensor cover. It is preferable that it is located away from the position facing the mouth. By arranging in this way, it is possible to prevent expiratory air from passing all at once from the expiratory air introduction hole to the intake port.

  It is also preferable to include a main body case that houses the expiratory flow path pipe, the gas sensor, and the drive measuring means, and a case ventilation hole that is provided near the gas sensor in the main body case. By doing so, it becomes easy to take in clean air outside the main body case around the gas sensor through the case ventilation hole of the main body case and the ventilation hole of the sensor housing wall.

  Further, it is also preferable to provide a liquid avoiding portion formed by elevating a portion of the inner peripheral surface of the exhalation flow passage pipe where the exhalation introducing hole is opened. The liquid avoidance portion allows water drops, saliva, and the like flowing into the flow path to flow around the exhalation introduction port.

  Further features of the invention and the advantages that it provides will be understood from the detailed description of the invention provided below.

1 shows an example of an exhaled breath component inspection device according to an embodiment of the present invention, where (a) is a front view, (b) is a sectional view taken along the line AA of (a), and (c) is BB of (a). A line sectional view, (d) is a rear view in a state where the extension pipe is mounted. The expiration flow pipe of the expiration component inspection apparatus same as the above is shown, (a) is a front view, (b) is a bottom view, (c) is a sectional view taken along the line CC of (b). The expiratory flow path pipe and the gas sensor attached to the expiratory flow path pipe are shown in (a) a perspective view and (b) a partially broken perspective view. It is a schematic explanatory drawing which shows the structure of a gas sensor.

  Hereinafter, an embodiment in which the present invention is applied to an alcohol testing apparatus (alcohol checker) for measuring the concentration of alcohol contained in exhaled breath and testing the degree of drunkenness (alcohol concentration in blood) will be described in detail.

  FIG. 1 shows the entire alcohol inspection apparatus. An upper part of a rectangular box-shaped main body case 1 forming an outer shell of the entire device, and an exhalation flow passage pipe 2 for allowing exhaled air blown by a user to pass in the axial direction thereof, and a sensor housing wall of the exhalation flow passage pipe 2. A gas sensor 3 (gas sensor 3 is not shown in FIG. 1) disposed in 18 is housed. Detailed structures of the gas sensor 3 and the expiratory flow passage pipe 2 will be described later.

  In the central portion of the main body case 1, a circuit board 4 for mounting circuit components including a microcomputer (hereinafter referred to as “microcomputer”) that performs control processing and a memory such as an EEPROM that stores reference data for drunkenness determination is housed. Has been done. The circuit board 4 is an appropriate drive measuring unit that drives the gas sensor 3 to measure the concentration of a predetermined gas component (ie, alcohol) to be detected contained in the exhaled breath. A battery storage chamber for storing the dry batteries 5 is formed in the lower portion of the main body case 1, and a pair of dry batteries 5 are stored in the battery by removing a battery cover 23 that is detachably attached to the lower rear portion of the main body case 1. It is removable in the room. The dry battery 5 is electrically connected to the circuit board 4 in the housed state, and constitutes a power supply unit for supplying power to the circuit board 4.

  A display window communicating with the internal space is opened on the front surface of the upper portion of the main body case 1, and a display window cover 6 made of a translucent resin is fitted into the display window. On the front side of the circuit board 4, a liquid crystal display section 7 in the form of a flat plate is arranged in a state of being electrically connected to the circuit board 4, and the liquid crystal display section 7 is visually recognized from the outside through the display window cover 6. It is possible. The liquid crystal display section 7 constitutes a liquid crystal display means for displaying the inspection result according to the measured density obtained by the driving process by the microcomputer.

  Further, an operation button 8 is arranged in a window hole formed below the display window of the main body case 1 so as to be pushed in from the outside. The operation button 8 is brought into contact with a power switch 9 mounted on the circuit board 4, and the power switch 9 is turned on/off by pushing the operation button 8 to turn on/off the power supply to the gas sensor 3 and the liquid crystal display unit 7. Is done.

  As shown in FIG. 4, the gas sensor 3 includes a cylindrical sensor cover 10 having a bottom, a resin base 11 that also serves as a bottom portion of the sensor cover 10, and a base 11 penetrating the inside and outside of the sensor cover 10. It is provided with three protruding terminals 12a, 12b, 12c and a sensor element 14 supported by connecting and fixing lead wires 13a, 13b, 13c to the terminals 12a, 12b, 12c in the sensor cover 10, respectively. . An intake port 15 is opened at the center of the tip surface (ceiling surface) of the sensor cover 10 so as to communicate with the internal space. Although a wire mesh 24 is further arranged at the intake port 15, it may be omitted.

  In the sensor element 14, a heater-combined electrode made of a noble metal wire is embedded in a gas-sensing body formed of a metal oxide semiconductor in an elliptical shape, and a core wire made of a precious metal wire is provided inside the heater-combined electrode. .. In addition, the lead wire 13b and one of the lead wires 13a and 13c form a terminal for measuring electric resistance, and the lead wire 13a and the lead wire 13c form a terminal for heating the heater. Then, each of the terminals 12a, 12b, 12c is connected to a conductive pattern formed on the surface of the circuit board 4 by an appropriate method such as soldering.

  Next, the structure of the exhalation flow passage pipe 2 arranged to supply the exhaled gas to the gas sensor 3 will be described in detail. As shown in FIG. 2, the expiratory flow pipe 2 is a cylindrical member that penetrates both ends in the axial direction, and one end side opening serves as an expiratory air inlet 2a and the other end side opening serves as an exhaled air outlet 2b. The diameter of the internal flow path of the expiratory flow path pipe 2 is formed in two stages via a step 2c in the middle of the flow path, and a half portion on the side communicating with the inlet 2a has a large diameter and communicates with the outlet 2b. The side half has a small diameter.

  An exhalation introduction hole 16 which is a small hole is formed in the radial direction at a position halfway on the side communicating with the inflow port 2a and immediately before the step 2c. A portion of the inner peripheral surface of the expiratory flow passage pipe 2 where the exhalation introducing hole 16 is opened is raised more than other portions, and this raised portion serves as a liquid avoidance portion 17. Although a pair of exhalation introducing holes 16 are formed in the illustrated example, one or more exhaling introducing holes 16 may be formed in the middle of the flow path.

  On the outer peripheral surface of the expiratory flow path pipe 2, a cylindrical sensor housing wall 18 extends in the radial direction. The sensor housing wall 18 is extended from a peripheral portion surrounding a pair of exhalation introducing holes 16 arranged side by side in the axial direction of the flow path. As shown in FIG. The shape is such that the sensor cover 10 of the gas sensor 3 is fitted from the opening side.

  Further, a pair of ventilation holes 19 are formed in a slit shape from the tip edge of the sensor housing wall 18. Although a pair of ventilation holes 19 are formed in the front direction and the back direction in the illustrated example, one or a plurality of the ventilation introducing holes 16 may be formed in a portion that communicates with an expiratory pool space 22 described later.

  The expiratory flow path pipe 2 is housed in the main body case 1 with the gas sensor 3 fitted in the sensor housing wall 18 as described above, and the inflow port 2a and the outflow port 2b at both ends in the axial direction projected to the outside. Fixed. In particular, the inflow port 2a side is projected to the extent that the user can hold it, but an extension pipe 20 as shown in FIG. 1(d) may be connected to the inflow port 2a side so as to communicate therewith. In addition, a plurality of slit-shaped case ventilation holes 21 are formed in a portion near the gas sensor 3 on the upper portion of the back side of the main body case 1. It is preferable that the case ventilation hole 21 is provided with appropriate means such as a filter for preventing foreign matter from entering from the outside.

  As shown in FIG. 3( b ), the gas sensor 3 fitted in the sensor housing wall 18 has its tip end surface forming the intake port 15 of the sensor cover 10 directed toward the outer peripheral surface side of the expiratory flow passage pipe 2, and The tip end surface and the outer peripheral surface of the expiratory flow path pipe 2 are locked with a predetermined gap maintained. The gap is the expiratory pool space 22 formed between the tip end surface of the sensor cover 10 and the outer peripheral surface of the expiratory flow passage pipe 2 and surrounded by the sensor housing wall 18.

  Here, the ventilation holes 19 provided in the sensor housing wall 18 are each provided with a length that reaches a position beyond the tip surface of the sensor cover 10 in the fitted state. Therefore, in the illustrated example, the distal end portion of the ventilation hole 19 (see P portion in FIG. 3A) is a ventilation hole portion communicating with the expiratory pool space 22.

  Further, the pair of exhalation introduction holes 16 formed in the exhalation flow passage pipe 2 are respectively directed toward the outer peripheral edge portion surrounding the intake port 15 on the tip end surface of the sensor cover 10 fitted in the sensor housing wall 18. It is provided at the opening position (see FIG. 3B). Therefore, the intake port 15 of the sensor cover 10 is opened toward the expiratory pool space 22 at a position deviated from the position facing the expiratory gas introduction holes 16. This is a structure avoiding that the intake port 15 and the exhalation introduction hole 16 are located opposite to each other.

  Then, in order to inspect the degree of drunkenness using the alcohol inspection apparatus having the above-described configuration, first, the operation button 8 is operated to energize the heater in the sensor element 14 of the gas sensor 3 to heat the sensor element 14 to a high temperature state. To do. In this high temperature state, the exhaled air is blown by holding the inflow port 2a side of the expiratory flow passage pipe 2 projecting laterally from the upper part of the main body case 1 and passing the exhaled air from the inflow port 2a side to the outflow port 2b side. Let

  Exhaled air that passes through the internal flow path of the expiratory flow path pipe 2 in the axial direction is partially introduced into the expiratory pool space 22 through the expiratory introduction hole 16 at a position immediately before the diameter becomes small through the step 2c. This exhaled air passes through the expiratory pool space 22 and then is taken into the sensor cover 10 through the intake port 15 and comes into contact with the sensor element 14. When the breath containing alcohol comes into contact with the sensor element 14 in a high temperature state, the resistance value of the gas-sensitive body decreases, and the microcomputer on the circuit board 4 appropriately detects the change in the resistance value to determine the degree of drunkenness. At the same time, the determination result is displayed on the liquid crystal display unit 7.

  Here, the exhaled gas to be introduced into the sensor element 14 in the gas sensor 3 passes through the exhaled gas introduction hole 16 in a direction orthogonal to the direction of flowing in the expiratory flow passage pipe 2 and the exhaled gas introduction hole 16 It is first introduced into the expiratory pool space 22, which is a larger space, and hits the outer peripheral edge portion surrounding the intake port 15 of the sensor cover 10 in the expiratory pool space 22. Then, after it is once caged in the exhalation pool space 22, it is taken into the sensor cover 10 through the intake port 15 and comes into contact with the sensor element 14. Therefore, even when the flow velocity or pressure of the expiratory air in which the user blows the expiratory flow into the expiratory flow passage pipe 2 is high, the sensor element 14 is not cooled rapidly and accurate measurement is possible. Moreover, the expiratory gas is quickly sent to the vicinity of the gas sensor 3 through the expiratory flow passage pipe 2, and then introduced into the gas sensor 3 through the expiratory gas introduction hole 16 and the expiratory pool space 22 which are present at a slight distance from the expiratory flow path pipe 2. Therefore, the gas sensor 3 can secure a fast sensitivity response.

  In addition, since the sensor housing wall 18 is provided with a slit-shaped ventilation hole 19 such that the tip portion thereof communicates with the expiratory pool space 22, the expiratory gas containing alcohol in the vicinity of the sensor element 14 at the time of measurement is breathed. Is quickly replaced with clean air after measurement through the ventilation hole 19 and the case ventilation hole 21 of the main body case 1. Therefore, accurate measurement can be performed without problems even when the breath is used continuously or when the breath having a low concentration is measured after the breath having a high concentration is measured. Here, in the alcohol testing apparatus of the present example, the expiratory pool space 22 in which the exhaled breath after measurement is likely to stay is a structure that requires a minimum space, and the ventilation hole 19 communicating with the expiratory pool space 22 is provided. The structure provided with contributes greatly to increasing the replacement speed around the gas sensor 3.

  In addition, it is also preferable to provide a fan motor or the like at an appropriate place in the main body case 1 as a blowing unit for introducing the outside clean air into the main body case 1 through the case ventilation hole 21. In this case, even when the size or position of the case ventilation hole 21 is limited due to various restrictions, it is possible to force ventilation. In other words, by providing the air blowing means such as the fan motor, it is possible to reduce the portion required for the case ventilation hole 21 in the main body case 1.

  The air forcedly sent from the outside by the blower means flows into the expiratory pool space 22 through the ventilation hole 19 and then reaches the inside of the expiratory flow passage pipe 2 through the expiratory air introduction hole 16 and the inside of the expiratory flow passage pipe 2 is reached. It will replace the exhaled air accumulated in. Even if it does not have an air blower, it may be gripped by the main body case 1 and shaken several times in the axial direction of the exhalation flow passage pipe 2 (left and right direction in FIG. 1A and FIG. 1D). Then, it is easy to quickly replace the expiratory air in the expiratory flow pipe 2 with clean air.

  In the alcohol testing apparatus of this example, since the exhaled air around the gas sensor 3 is quickly replaced as described above, the output from the gas sensor 3 changes to the clean direction when the blowing of the exhaled air is interrupted during the measurement. It's easier to catch things. Therefore, it is possible to provide a blowing interruption detection function of detecting the blowing interruption based on the output of the gas sensor 3. When such a blowing interruption detection function is provided, it is preferable that if the blowing interruption is detected, the measurement is stopped and the liquid crystal display section 7 displays that the measurement is invalid.

  In the expiratory flow pipe 2, the water in the exhaled air may adhere and water droplets of a larger size may flow out or saliva may flow in from the inflow port 2a side. The liquid avoiding portion 17 is formed by raising the opening of the exhalation introducing hole 16 so that the liquid such as water droplets and saliva bypasses the exhaling introducing hole 16 and detours to the outlet 2b. It is like this.

  As described above, according to the present invention, it is possible to perform accurate measurement without any problems even when continuously measuring or measuring low-concentration exhalation after measuring high-concentration exhalation, and interrupting blowing It is also possible to provide a detection function, and it is possible to provide an exhalation component testing device that has a fast sensitivity response.

  Further, as described above, the breath component testing device of the present invention is preferably used as an alcohol testing device for measuring the alcohol concentration in breath to test the degree of drunkenness caused by drinking alcohol, but other various breath components may be used. It can be widely used as an exhaled breath component inspection device having a structure for detection by a gas sensor.

[0003]
It is.
[0009] Here, the expiratory pool space is configured to exist for a short distance between the flow channel in the expiratory flow channel pipe and the gas sensor. It is in communication and ventilation is easy. Therefore, since the ventilation around the gas sensor is very good, accurate measurement can be performed without any problems even when performing continuous measurement or measuring high-concentration breath and then low-concentration breath. It is also possible to provide a blowing interruption detection function.
[0010] It is also preferable that the ventilation hole is a slit-shaped hole that is recessed from the tip edge of the sensor housing wall and that the tip portion is a communicating portion with the exhalation pool space.
[0011] In the gas sensor, a sensor element is arranged in a sensor cover formed by opening an intake port toward the expiratory flow path pipe side, and the expiratory gas introduction hole of the expiratory flow path pipe has a sensor cover. It is preferable that it is located away from the position facing the intake port of. By arranging in this way, it is possible to prevent expiratory air from passing all at once from the expiratory air introduction hole to the intake port.
[0012] It is also preferable to include a main body case that houses the expiratory flow passage pipe, the gas sensor, and the drive measuring means, and a case ventilation hole that is provided near the gas sensor in the main body case. By doing so, it becomes easy to take in clean air outside the main body case around the gas sensor through the case ventilation hole of the main body case and the ventilation hole of the sensor housing wall.
[0013] Further, it is also preferable to include a liquid avoiding portion formed by bulging a portion of the inner peripheral surface of the exhalation flow passage pipe where the exhalation introduction hole is opened. The liquid avoidance portion allows water drops, saliva, and the like flowing into the flow path to flow around the exhalation introduction port.
[0014] Further features of the invention and the advantages that it provides will be understood from the detailed description of the invention provided below.
[Brief description of drawings]
[0015] [Fig. 1] Fig. 1 shows an example of an exhalation component inspection device according to an embodiment of the present invention, in which (a) is a front view, (b) is a cross-sectional view taken along the line AA of (a), and (c) is. FIG. 7A is a cross-sectional view taken along the line BB, and FIG. 7D is a rear view with an extension pipe attached.

Claims (5)

An exhalation flow passage pipe that blows in and passes exhalation, an exhalation introduction hole that is formed in the passage of the exhalation passage pipe, and extends from a portion surrounding the exhalation introduction hole on the outer peripheral surface of the exhalation passage pipe. It is formed between a certain cylindrical sensor housing wall, a gas sensor fitted into the sensor housing wall to detect a predetermined gas component in the exhaled air, and a gas sensor fitted in the sensor housing wall and the expiratory gas introduction hole. An expiratory pool space, a ventilation hole formed in the sensor housing wall at a position communicating with the expiratory pool space, and a drive measuring means for driving the gas sensor to measure the concentration of a predetermined gas component contained in the expired gas. An exhaled breath component inspection device comprising: The breath component testing device according to claim 1, wherein the ventilation hole is a slit-shaped hole that is recessed from the front edge of the sensor housing wall. The gas sensor is one in which a sensor element is arranged in a sensor cover formed by opening an intake port toward the expiratory flow path pipe side, and the expiratory introduction hole of the expiratory flow path pipe is the intake of the sensor cover. The exhaled breath component inspection device according to claim 1 or 2, wherein the exhaled breath component inspection device is located away from a position facing the mouth. The main body case for accommodating the expiratory flow path pipe, the gas sensor, and the drive measuring means, and a case ventilation hole provided near the gas sensor of the main body case are provided. The exhaled breath component inspection device according to. The exhalation breath component inspection device according to any one of claims 1 to 4, further comprising: a liquid avoiding portion formed by elevating a portion of the inner circumferential surface of the exhalation passage pipe where the exhalation introduction hole is opened.

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