JP7189011B2 - Exhaled gas detection device - Google Patents

Description

The present disclosure relates to an exhaled gas detection device.

Various devices have been proposed as breath gas detection devices for detecting a specific gas (specific component) contained in the breath of a subject.
For example, a diagnostic gas analyzer (Patent Document 1) includes a valve (three-way valve 9 or the like) for changing the gas flow path. In the breath analysis system (Patent Document 2), a gas channel (250) for taking ambient air into an analyzer (215), a gas channel (250) for taking exhaled breath (240) of a subject (human body) into the analyzer (215), are provided separately.

Japanese Patent No. 4472533 Japanese Patent No. 5848608

However, as in the above-described conventional apparatus, a configuration including a valve or a configuration including a plurality of gas flow paths increases the number of constituent members, which may cause problems such as an increase in cost and a complication of the configuration of the apparatus.

Therefore, in one aspect of the present disclosure, it is desirable to provide an exhaled gas detection device capable of realizing cost reduction and simplification of device configuration in detecting a specific gas in exhalation of a subject.

One aspect of the present disclosure is an exhalation gas detection device that detects a specific gas contained in exhalation of a subject, and includes a main body, a mouthpiece, a gas detection section, and a foreign object removal section.
The main body has a gas flow path. The gas flow path is composed of a single gas flow path that extends from the first opening to the second opening, and is configured to allow exhaled air to pass therethrough. A mouthpiece is provided so as to be connected to the gas flow path at the first opening. The mouthpiece is configured to allow the subject to blow air in and the subject to inhale. The gas detection unit is provided in the gas flow path and configured to detect a specific gas. The foreign matter removal section is provided in a region of the gas flow path closer to the second opening than the gas detection section, and is configured to remove at least the specific gas.

The gas flow path is configured to communicate with the outside of the main body through the first opening and the second opening.
In the expiratory gas detection device configured in this way, when the subject inhales through the mouthpiece, the gas in the gas flow path is discharged from the first opening to the outside of the gas flow path, and the outside air ( atmosphere) into the interior of the gas flow path. In addition, in this expired gas detection device, when the subject blows into the mouthpiece, the expired gas is introduced into the gas channel through the first opening, and the gas (exhaled breath) in the gas channel is introduced into the second opening. It is configured to be discharged to the outside from the

The expiratory gas detection device having such a configuration does not require a pump for moving gas (exhaled breath) or a valve for opening and closing the gas flow path, and the breathing action of the subject can be either an exhalation action or an inhalation action. By switching, introduction of exhaled breath into the gas detection unit and introduction of the reference gas (atmosphere) into the gas detection unit can be achieved.

Therefore, according to this exhaled gas detection device, members such as pumps and valves are not required to detect the specific gas in the exhaled breath of the subject, so that the configuration of the device can be simplified and the manufacturing cost can be reduced.

A user (a subject, a doctor, a nurse, etc.) of the breath gas detection device determines the degree of existence of a specific gas contained in breath using, for example, the reference gas value and the detected gas value. good too. Specifically, the user may determine the degree of presence of the specific gas contained in exhaled air based on the result of comparison between the reference gas value and the sensed gas value. Note that the reference gas value is a state quantity corresponding to the detection result by the gas detection unit when the reference gas is introduced into the gas detection unit by an inhalation action by the subject. The detected gas value is a state quantity corresponding to the result of detection by the gas detection unit when breath is introduced into the gas detection unit by the patient's breath blowing operation.

In this case, for example, the detection timing of the reference gas value and the detection timing of the detected gas value are determined in advance, and the subject performs an inhalation operation and an exhalation operation according to each timing, thereby obtaining the reference gas value and the detected gas value. value can be obtained. As an index related to "the degree of presence of a specific gas contained in exhaled air", the concentration of the specific gas may be used, or a step index that evaluates the amount of the specific gas in several levels (e.g., It may be evaluated by levels such as large, medium, and small abundance), or it may be the result of the presence/absence of a specific gas.

Next, the above-described breath gas detection device may include a movement direction determination section. The movement direction determination section is provided in the gas flow path. The movement direction determination unit determines whether the movement direction of the gas flowing inside the gas flow path is a first direction from the first opening to the second opening or a second direction from the second opening to the first opening. direction.

By including such a movement direction determination unit, the expiration gas detection device can determine the reference gas value using the determination result of the movement direction determination unit even when the subject inhales and blows air at arbitrary timing. The detection timing and the detection timing of the detected gas value can be determined. As a result, by using the determination result of the moving direction determination unit, the expired gas detection device can detect the detection timing of the reference gas value and the detected gas value based on the determination result of the movement direction determination unit without predetermining the detection timing of the reference gas value and the detection timing of the detected gas value. can be used to obtain the reference gas value and the detected gas value.

The breath gas detection device may include a notification unit that notifies the user of the determination result of the movement direction determination unit. The notification unit may be, for example, a display form using a lamp or the like, a voice notification form using sound, or a form of outputting to an external device in the form of a signal.

Next, in the above-described exhaled gas detection device including the moving direction determining section, the moving direction determining section may include a flow rate sensor capable of measuring the flow rate of the fluid and the moving direction of the fluid.
The moving direction determination unit having such a configuration can determine whether the moving direction of the gas flowing inside the gas flow path is the first direction or the second direction based on the detection result of the flow sensor.

Next, the above-described breath gas detection device may include a detection determination section that determines the degree of presence of the specific gas contained in the breath based on the detection result of the gas detection section. The detection determination unit is configured to determine the degree of presence of the specific gas contained in exhaled air using the reference gas value and the detected gas value. The reference gas value is a state quantity corresponding to the detection result by the gas detection unit when the atmosphere (reference gas) is introduced into the gas detection unit by the subject's inhalation. The detected gas value is a state quantity corresponding to the result of detection by the gas detection unit when breath is introduced into the gas detection unit by the patient's breath blowing operation.

Such an exhaled gas detection device is provided with a detection determination unit, so that the user does not have to compare the reference gas value and the detected gas value or analyze the values, and can detect the gas based on the determination result of the detection determination unit. , the degree of presence of the specific gas contained in exhalation can be easily determined. The index for the degree of presence of the specific gas contained in exhaled air may be the concentration of the specific gas, or a graded index that evaluates the amount of the specific gas in several stages (for example, the amount of presence is large). , medium, and small), or the result of presence/absence of a specific gas.

Note that the detection determination unit may be provided inside the main body, or may be provided outside the main body.
Next, in the above-described exhaled gas detection device, the gas detection section may be configured using a mixed potential type sensor. By using such a mixed potential sensor, it is possible to detect a specific gas (for example, nitrogen oxides, etc.) contained in exhaled air. Note that the mixed potential sensor may be configured using, for example, a solid electrolyte body and a pair of electrodes arranged on the surface of the solid electrolyte body.

Next, in the breath gas detection device described above, the specific gas may be nitric oxide. Such an exhaled gas detection device can determine the degree of presence of nitric oxide contained in exhaled air of a subject, and can determine the health condition of the subject (whether or not the subject has asthma, etc.).

Next, in the above-described breath gas detection device in which the specific gas is nitric oxide, the mouthpiece may include an adsorption portion that adsorbs at least one of the humidity component, NO ₂ and acetonitrile.

Such an exhaled gas detection device can reduce at least one of the humidity component, NO ₂ , and acetonitrile from the exhaled air when exhaled air is introduced into the gas detection unit. , the error due to the influence of the humidity component, NO ₂ , and acetonitrile at the time of detection of the detected gas value can be reduced.

Next, in the exhaled gas detection device described above, the foreign matter removing section may include at least potassium permanganate. Such an exhaled gas detection device can remove miscellaneous gas components from the atmosphere when the reference gas (atmosphere) is introduced into the gas detection unit, and can improve the detection accuracy of the specific gas. Especially when the specific gas is nitric oxide, the gas detection accuracy can be effectively improved by using the foreign matter removing section.

Next, in the expired gas detection device described above, the mouthpiece may have a throttle structure for adjusting the flow rate of expired air. By using such a mouthpiece, the exhaled gas detection device detects the degree of existence of the specific gas from the exhaled breath of the subject, and determines the health condition of the subject (for example, the degree of asthma symptoms). Expiratory pressure suitable for criteria can be ensured.

Next, in the breath gas detection device, the mouthpiece may be detachably attached to the main body. A breath gas detection device with such a configuration can replace the mouthpiece for each subject, so it is possible to test a large number of subjects while suppressing the spread of virus infection through the mouthpiece among multiple subjects. becomes.

It is an explanatory view showing the internal configuration of the breath gas detection device. FIG. 10 is an explanatory diagram schematically showing the state of movement of gas in the gas flow path during the subject's exhalation blowing action; FIG. 4 is an explanatory diagram schematically showing the state of movement of gas in a gas flow path during inhalation by a subject. 4 is a flow chart showing the processing contents of gas detection processing. FIG. 10 is an explanatory diagram schematically showing the internal configuration of the gas flow path in the breath gas detection device of the second embodiment; FIG. 11 is an explanatory diagram schematically showing the internal configuration of a gas flow path in the breath gas detection device of the third embodiment;

Embodiments to which the present disclosure is applied will be described below with reference to the drawings.
It goes without saying that the present disclosure is not limited to the following embodiments, and various forms can be adopted as long as they fall within the technical scope of the present disclosure.

[1. First Embodiment]
[1-1. overall structure]
The breath gas detection device 1 of this embodiment is a device for detecting a specific gas (specific component) contained in the breath of a subject.

The breath gas detection device 1 may be used in fields such as medicine. The exhaled gas detection device 1 can be suitably used for measurement of gas containing extremely low concentrations of nitric oxide (NO) at several ppb to several hundred ppb levels, specifically for asthma diagnosis.

As shown in FIG. 1, the exhaled gas detection device 1 includes a mouthpiece 11, a body portion 13, a cap 15, a flow rate sensor 21, a gas detection portion 23, a foreign matter removal portion 25, and a first control portion 31. and a second control unit 33 .

In order to show the internal structure of the expired gas detection device 1, FIG. 1 shows the internal structure in a state where the mouthpiece 11 and the body portion 13 are cut in half. In this specification and the like, of the longitudinal ends of the respiratory gas detection device 1, the end provided with the mouthpiece 11 is defined as the leading end, and the end provided with the cap 15 is defined as the rear end.

[1-2. Configuration of each part]
The mouthpiece 11 is configured in a shape that the subject can put his or her mouth on so that the subject can perform an exhalation operation and an inhalation operation by the subject. The mouthpiece 11 includes an opening 11a, an internal space 11b, and a connecting portion 11c. Mouthpiece 11 internally includes a gas path from opening 11a to connecting portion 11c via internal space 11b. The connecting portion 11 c is configured to be detachably fitted to the tip end portion of the body portion 13 .

The mouthpiece 11 has an aperture structure for adjusting the flow rate of exhaled air in the internal space 11b. By using the mouthpiece 11 having such an aperture structure, the degree of presence of nitric oxide in exhaled breath of the subject is detected, and an expiratory pressure suitable for the criteria for judging the degree of asthma symptoms is ensured. can do. In this embodiment, the concentration of nitrogen monoxide is detected as the detection of the degree of presence of nitrogen monoxide, which is a specific gas.

Mouthpiece 11 has adsorbent 11d in internal space 11b. The adsorbent 11d is configured to adsorb at least part of the humidity component of the gas (breath) introduced into the internal space 11b. The adsorbent 11d may be configured using activated alumina, activated carbon, zeolite, silica gel, or the like, for example.

The body portion 13 has an elongated shape extending from the front end to the rear end. The body portion 13 includes therein a gas flow path 13a serving as a flow path for exhalation. The gas channel 13 a is a gas channel having a first opening 13 b provided at the tip of the main body 13 and a second opening 13 c provided at the rear end of the main body 13 .

The gas channel 13a is formed as one gas channel that extends from the first opening 13b to the second opening 13c. The gas flow path 13a is configured to be connected to the outside of the main body 13 only through the first opening 13b and the second opening 13c.

The body portion 13 accommodates the flow rate sensor 21 , the gas detection portion 23 , the foreign matter removal portion 25 , the first control portion 31 and the second control portion 33 . Among them, the flow rate sensor 21, the gas detection section 23, and the foreign matter removal section 25 are arranged in this order from the first opening 13b to the second opening 13c in the gas flow path 13a.

By fitting the connection portion 11c of the mouthpiece 11 to the distal end portion of the main body portion 13, the mouthpiece 11 is provided so as to be connected to the first opening portion 13b of the gas flow path 13a.
The flow rate sensor 21 is a sensor configured to be able to measure the flow rate of fluid and the moving direction of the fluid. The flow rate sensor 21 can measure the flow rate and movement direction of the gas (exhalation, air) flowing through the gas flow path 13a.

Therefore, the flow rate of exhaled breath blown by the subject can be determined based on the measurement result of the gas flow rate by the flow sensor 21 . In addition, based on the measurement result of the gas flow rate by the flow sensor 21, it is possible to determine the start time of exhalation by the subject and the duration of exhalation. Furthermore, based on the measurement result of the direction of gas movement by the flow sensor 21, it can be determined whether the subject is inhaling or inhaling.

It should be noted that during the exhalation blowing operation by the subject, as schematically shown in FIG. to move. Further, since the gas flow path 13a becomes negative pressure during inhalation by the subject, as schematically shown in FIG. It moves from the second opening 13c of the path 13a toward the first opening 13b.

By providing the flow rate sensor 21, it becomes possible to determine whether or not each of the exhalation blowing operation and the inhalation operation is performed at an appropriate flow rate for an appropriate time.
The gas detection unit 23 is a gas sensor that detects nitrogen oxides. The gas detection unit 23 is configured using, for example, a known mixed potential sensor. The gas detection unit 23 of this embodiment includes a catalyst unit for converting NO into NO ₂ on the upstream side of the gas (breath) introduced into the mixed potential sensor. Then, NO contained in exhalation is converted to NO ₂ by the catalyst unit, and the concentration of NO ₂ is detected by the mixed potential type sensor. Although the mixed potential sensor detects the concentration of NO ₂ , the concentration is detected by converting the NO contained in the exhaled air into NO ₂ by the catalyst. detects the concentration of NO as a specific gas. That is, by considering the conversion efficiency of NO to NO ₂ by the catalyst unit, the concentration of NO can be calculated based on the sensor signal corresponding to the concentration of NO ₂ output from the mixed potential sensor, and exhalation A gas detection device 1 is a device for detecting nitric oxide (NO) contained in exhalation of a subject.

Here, when the subject performs an exhalation blowing operation, the exhaled air is introduced into the gas flow path 13a from the first opening 13b through the mouthpiece 11 and reaches the gas detection unit 23. Therefore, the detection by the gas detection unit 23 at this time The result corresponds to the specific gas (NO) content in exhaled breath. That is, the state quantity (detection result signal) corresponding to the detection result at this time can be used as a detection gas value corresponding to the state of the specific gas contained in exhalation of the subject.

Note that the gas detection unit 23 is not limited to the configuration using the mixed potential type sensor, and may be configured using an arbitrary gas sensor. For example, the gas detection unit 23 may be configured using an electrochemical sensor, an oxide semiconductor sensor, or the like. Further, in the gas detection unit 23 of the present embodiment, a configuration provided with a catalyst unit that converts NO into NO ₂ is adopted. good.

The foreign matter removing section 25 is configured to incorporate an adsorbent containing at least potassium permanganate. As a result, the air introduced into the gas flow path 13a from the second opening 13c during the subject's inhalation movement passes through the foreign matter removing unit 25, and the miscellaneous gas components (nitrogen oxides) contained in the air pass through the foreign matter. After being removed by the removal unit 25 , it reaches the gas detection unit 23 . The detection result of the gas detection unit 23 at this time is the detection result for a gas that does not contain nitrogen oxides, and the state quantity (detection result signal) corresponding to this detection result is the reference gas value when nitrogen monoxide is detected. available as

The cap 15 is configured to be fittable with the rear end portion of the body portion 13 . The cap 15 has a vent hole 15a through which gas (exhaled breath, atmospheric air, etc.) can pass. The cap 15 is provided so that the ventilation hole 15a is connected to the second opening 13c of the gas flow path 13a by fitting with the rear end of the main body 13 .

Next, the first control unit 31 and the second control unit 33 are each configured with a microcomputer (hereinafter also referred to as a microcomputer, not shown) that performs various arithmetic processing.
The microcomputer includes a CPU, ROM, RAM, and the like. Various functions of the microcomputer are realized by the CPU executing a program stored in a non-transitional substantive recording medium. In this example, the ROM corresponds to a non-transitional substantive recording medium storing programs. Also, by executing this program, a method corresponding to the program is executed. The number of microcomputers provided in each of the first control unit 31 and the second control unit 33 may be one or more. Also, part or all of the functions executed by the microcomputer may be configured as hardware using one or a plurality of ICs or the like.

[1-3. Various processing]
The first controller 31 is configured to receive the measurement result signal from the flow sensor 21 . The first control section 31 is configured to execute various determination processes based on the measurement result signal. Various types of determination processing include, for example, gas movement determination processing, expiration/inhalation operation determination processing, expiration flow rate determination processing, and expiration time determination processing.

The gas movement determination process is a process of determining whether or not gas movement occurs in the gas flow path 13a based on the measurement result signal. The expiratory/inspiratory motion determination process is a process for determining whether the subject is inhaling or inhaling, based on the measurement result signal. The expiratory flow rate determination process is a process of determining the flow rate of exhaled air blown by the subject based on the measurement result signal. The expiration time determination process is a process of determining the start time of exhalation by the subject and the duration of exhalation by the subject based on the measurement result signal.

The second control section 33 is configured to receive a detection result signal from the gas detection section 23 . The second control section 33 is configured to transmit and receive various information to and from the first control section 31 . The second control unit 33 is configured to receive determination results of various determination processes from the first control unit 31 . The second control unit 33 is configured to execute a gas detection process based on the detection result signal and determination results of various determination processes.

The gas detection process determines the degree of presence of a specific gas (nitrogen monoxide in this embodiment) contained in the subject's exhalation (in this embodiment, the amount of the specific gas density). The second control unit 33 starts gas detection processing when the expired gas detection device 1 is activated.

As shown in the flowchart of FIG. 4, when the second control unit 33 starts the gas detection process, first, in S110 (S represents a step), it is determined whether gas movement is occurring in the gas flow path 13a. If the determination is affirmative, the process proceeds to S120, and if the negative determination is made, the same steps are repeatedly executed and the system waits. It should be noted that the determination in S110 is made based on the determination result received from the first control unit 31 .

When an affirmative determination is made in S110 and the process proceeds to S120, the second control unit 33 determines whether or not the subject is inhaling. This step S120 is a determination step for determining whether the subject is inhaling or exhaling.

When an affirmative determination is made in S120 and the process proceeds to S130, the second control unit 33 stores the state quantity corresponding to the detection result signal received from the gas detection unit 23 as the reference gas value G1. At this time, the state quantity (detection result signal) corresponding to the detection result received from the gas detection unit 23 can be used as the reference gas value G1, which is the state quantity corresponding to the detection result for the gas (atmosphere) that does not contain nitrogen oxides. .

When a negative determination is made in S120 and the process proceeds to S140, the second control unit 33 stores the state quantity corresponding to the detection result signal received from the gas detection unit 23 as the detected gas value G2. At this time, the state quantity (detection result signal) corresponding to the detection result received from the gas detection unit 23 can be used as the detection gas value G2 corresponding to the content of the specific gas in the exhalation of the subject.

In the next S150, a difference value D1 (=G2-G1) between the reference gas value G1 stored in S130 and the detected gas value G2 stored in S140 is calculated. In the next step S160, determination of the specific gas (NO), more specifically, calculation of the concentration of the specific gas (NO) is performed based on the difference value D1. In S160, for example, based on the correlation between the concentration of the specific gas and the difference value D1, the specific gas ( NO) concentration can be calculated.

In the next step S170, the determination result (the result of the concentration calculation of the specific gas) is notified to the user by, for example, video display on the liquid crystal screen, lamp display, voice notification, or the like.
After executing either S130 or S170, the second control unit 33 ends the gas detection process.

In the exhaled gas detection device 1, the measurement result signal from the flow sensor 21 and the detection result signal from the gas detection part 23 are obtained by the first control part 31 and the second control part 33 executing various processes in this manner. is used to detect (determine) the degree of presence of a specific gas (nitrogen monoxide) contained in exhaled air.

[1-4. effect]
As described above, in the expired gas detection device 1 of the present embodiment, when the subject inhales through the mouthpiece 11, the gas inside the gas flow path 13a flows out of the gas flow path 13a through the first opening 13b. The exhaled gas detection device 1 is configured to take in outside air (atmosphere) from the second opening 13c into the inside of the gas flow path 13a. Exhaled air is introduced into the gas passage 13a through the first opening 13b, and the gas (exhaled air) inside the gas passage 13a is discharged to the outside through the second opening 13c.

The expiratory gas detection device 1 having such a configuration can switch the breathing operation of the subject between an exhalation blowing operation and an inhalation operation without providing a pump for moving the exhaled breath or a valve for opening and closing the gas flow path. Thus, the introduction of exhaled breath into the gas detection unit 23 and the introduction of the reference gas (atmosphere) into the gas detection unit 23 can be achieved.

Therefore, according to the exhaled gas detection device 1, members such as pumps and valves are not required for detecting the specific gas (nitrogen monoxide) in the exhaled breath of the subject. can be reduced.

Next, the expired gas detection device 1 includes a flow rate sensor 21 provided in the gas flow path 13a. The flow sensor 21 determines whether the moving direction of the gas (exhaled air, atmosphere) flowing inside the gas flow path 13a is the first direction from the first opening 13b to the second opening 13c, or from the second opening 13c. It can be determined whether it is the second direction toward the first opening 13b.

By including such a flow sensor 21, the expiratory gas detection device 1 can detect the reference gas value G1 using the measurement result signal of the flow sensor 21 even when the subject inhales and blows air at arbitrary timing. and the detection timing of the detected gas value G2 can be determined. As a result, by using the measurement result signal of the flow sensor 21, the expired gas detection device 1 can detect the measurement result signal of the flow sensor 21 without predetermining the detection timing of the reference gas value G1 and the detection timing of the detected gas value G2. The reference gas value G1 and the detected gas value G2 can be obtained based on.

Next, based on the measurement result signal of the flow rate sensor 21 and the detection result signal of the gas detection part 23, the expired gas detection device 1 determines the degree of existence of the specific gas contained in the exhaled gas. 2 control unit 33 is provided.

That is, when the second control unit 33 that executes the gas detection process determines that the subject is inhaling based on the determination result received from the first control unit 31 (positive determination in S120), the detection result signal at that time is stored as the reference gas value G1 (S130). Further, when the second control unit 33 determines that the subject is not inhaling (in other words, the subject is exhaling) based on the determination result received from the first control unit 31 (NO in S120). judgment), and the state quantity corresponding to the detection result signal at that time is acquired as the detected gas value G2 (S140). After acquiring the detected gas value G2, the second control unit 33 determines the degree of presence of the specific gas contained in exhaled air based on the result of comparison between the detected gas value G2 and the reference gas value G1 (S150, S160). . Specifically, the second control unit 33 determines the specific gas, more specifically, calculates the concentration of the specific gas, based on the difference value D1 between the detected gas value G2 and the reference gas value G1.

Therefore, by including the first control unit 31 and the second control unit 33, the exhaled gas detection device 1 allows the user (subject, doctor, nurse, etc.) to compare the reference gas value G1 and the detected gas value G2. It is possible to easily determine the degree of presence of the specific gas contained in exhaled air based on the determination results of the first control unit 31 and the second control unit 33 without analyzing these values.

Next, the exhaled gas detection device 1 is equipped with a foreign matter removing section 25 containing an adsorbent containing potassium permanganate. As a result, the exhaled gas detection device 1 allows the gas passage 13a to be introduced from the second opening 13c when the subject performs an inhalation operation (in other words, when the reference gas (atmosphere) is introduced into the gas detection unit 23). Since the miscellaneous gas components can be removed from the atmosphere, the miscellaneous gas components in the atmosphere can be suppressed from reaching the gas detection unit 23, and the detection accuracy of the specific gas can be improved.

Next, the breath gas detector 1 has an adsorbent 11d in the internal space 11b of the mouthpiece 11. As shown in FIG. As a result, the expired gas detection device 1 can reduce the humidity component from the expired gas when the expired gas is introduced into the gas detection unit 23, and when detecting the specific gas, the error caused by the humidity component at the time of detection of the detected gas value G2 can be reduced. can be reduced.

Note that the adsorbent 11d is not limited to one that adsorbs the humidity component, and may be an adsorption portion that adsorbs at least one of the humidity component, NO ₂ and acetonitrile. As a result, at least one of the humidity component, NO ₂ , and acetonitrile can be reduced from the exhaled air when exhaled air is introduced into the gas detection unit 23, and when detecting nitric oxide (NO) as the specific gas, the detected gas value G2 It is possible to reduce errors due to the effects of humidity components, NO ₂ , and acetonitrile when detecting .

Next, in the expired gas detection device 1, the connection portion 11c of the mouthpiece 11 is configured to be detachably fitted to the distal end portion of the body portion 13. As shown in FIG. As a result, the exhaled gas detection device 1 can replace the mouthpiece for each subject, so it is possible to test a large number of subjects while suppressing the spread of virus infection through the mouthpiece 11 among multiple subjects. becomes.

[1-5. Correspondence of wording]
Here, the correspondence between wordings will be described.
The breath gas detection device 1 corresponds to an example of the breath gas detection device, the main body portion 13 corresponds to an example of the main body portion, the gas channel 13a corresponds to an example of the gas channel, and the mouthpiece 11 corresponds to an example of a mouthpiece. corresponds to

The gas detection unit 23 corresponds to an example of the gas detection unit, the foreign matter removal unit 25 corresponds to an example of the foreign matter removal unit, the flow rate sensor 21 corresponds to an example of the movement direction determination unit, and the first control unit 31 and the second The control unit 33 corresponds to an example of a detection determination unit, and the adsorbent 11d corresponds to an example of an adsorption unit.

[2. Other embodiments]
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and can be implemented in various forms without departing from the gist of the present disclosure.

For example, in the above-described embodiment, the moving direction determination section (flow rate sensor), the gas detection section, and the foreign matter removal section arranged in the gas flow path are arranged in this order from the first opening to the second opening. Although the embodiment has been described, the arrangement order of these elements inside the gas flow path is not limited to the same as in the above embodiment. For example, "a configuration in which a gas detection unit, a movement direction determination unit (flow rate sensor), and a foreign matter removal unit are arranged in this order from the first opening to the second opening in the gas flow path" (second embodiment; see FIG. 5). ) can be used. Alternatively, "a configuration in which a gas detection section, a foreign matter removal section, and a movement direction determination section (flow rate sensor) are arranged in this order from the first opening to the second opening in the gas flow path" (third embodiment; see FIG. 6). ) can be used. That is, it is preferable that the foreign matter removing portion is provided in a region of the gas flow path closer to the second opening than the gas detecting portion.

Next, the mouthpiece is not limited to being detachable from the main body, and may be formed integrally with the main body.
Next, the exhaled gas detection device is not limited to the configuration in which the first control unit and the second control unit are built in the main unit, but the configuration in which the first control unit and the second control unit are provided separately from the main unit. may be In that case, by providing a signal path for transmitting the measurement result signal of the movement direction determination unit (flow rate sensor) and the detection result signal of the gas detection unit to the first control unit and the second control unit, the gas detection process can be performed. can run.

Next, the expiration gas detection device is not limited to the configuration in which the gas detection process is performed only once after startup, and may be configured to repeatedly perform the gas detection process. For example, the second control unit 33 may be configured to start the gas detection process again when a predetermined re-detection time elapses after the gas detection process ends. In this way, if the gas detection process is repeatedly executed, the work of detecting the specific gas contained in exhaled air can be repeatedly executed, so when diagnosing a large number of subjects, there is no need to perform the activation operation for each subject. , the waiting time for diagnosis can be shortened.

Next, the expired gas detection device may include a notification unit that notifies the user of the determination result of the moving direction determination unit. The notification unit may be, for example, a display form using a liquid crystal screen or a lamp, a voice notification form using sound, or a form of outputting to an external device in the form of a signal.

Next, the function of one component in the above embodiment may be assigned to a plurality of components, or the function of a plurality of components may be performed by one component. Also, part of the configuration of the above embodiment may be omitted. Also, at least part of the configuration of the above embodiment may be added, replaced, or the like with respect to the configuration of another embodiment. It should be noted that all aspects included in the technical idea specified by the wording in the claims are embodiments of the present disclosure.

REFERENCE SIGNS LIST 1 expiratory gas detection device 11 mouthpiece 11a opening 11d adsorbent 13 main body 13a gas flow path 13b first opening 13c second opening 21 flow rate Sensor, 23...Gas detection part, 25... Foreign matter removal part, 31...First control part, 33...Second control part.

Claims (9)

A breath gas detection device for detecting a specific gas contained in the breath of a subject,
a main body portion including a single gas flow path extending from a first opening to a second opening and through which the exhaled gas passes;
a mouthpiece that is provided so as to connect to the gas flow path at the first opening and is configured to allow the subject to perform the exhalation blowing operation and the subject's inhalation operation;
a gas detection unit that is provided in the gas flow path and detects the specific gas;
a foreign matter removal section provided in a region of the gas flow path closer to the second opening than the gas detection section and removing at least the specific gas;
a detection determination unit that determines the degree of presence of the specific gas contained in the exhaled gas based on the detection result of the gas detection unit;
with
The gas flow path is configured to be connected to the outside of the main body through the first opening and the second opening,
The detection determination unit determines a reference gas value, which is a state quantity corresponding to the detection result of the gas detection unit when air is introduced into the gas detection unit by an inhalation operation of the subject, and the Determining the degree of presence of the specific gas contained in the exhaled gas using a detected gas value, which is a state quantity corresponding to a detection result by the gas detecting unit when the exhaled breath is introduced into the gas detecting unit,
Exhaled gas detection device. The movement direction of the gas provided in the gas flow path and flowing inside the gas flow path is the first direction from the first opening toward the second opening, or from the second opening toward the second opening. 1 comprising a movement direction determination unit that determines whether it is the second direction toward the opening,
The breath gas detection device according to claim 1. The moving direction determination unit includes a flow sensor configured to measure the flow rate of the fluid and the moving direction of the fluid.
The breath gas detection device according to claim 2. The gas detection unit is configured using a mixed potential sensor,
The breath gas detection device according to any one of claims 1 to 3. The specific gas is nitric oxide,
The breath gas detection device according to any one of claims 1 to 4. The mouthpiece includes an adsorption portion that adsorbs at least one of humidity components, NO ₂ , and acetonitrile,
The breath gas detection device according to claim 5 . The foreign matter removing unit comprises at least potassium permanganate,
The breath gas detection device according to any one of claims 1 to 6 . wherein the mouthpiece comprises an aperture structure for adjusting the flow rate of the exhaled air;
The breath gas detection device according to any one of claims 1 to 7. The mouthpiece is configured to be detachable from the main body,
The breath gas detection device according to any one of claims 1 to 8.

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