JPH10186A - Method and device of analyzing specified gas component in expired air - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely eliminate the expired air of a dead space part by detecting a specified gas component by a detector, arithmetically processing its signal by an arithmetic processing part, calculating the concentration of the specified gas component from a preliminarily stored calibration curve, and storing it as clinical inspection data. SOLUTION: The expired air B blown through a mouth piece 12 is measured by a flow rate sensor 9 and discharged, and in the stage where the discharge quantity exceeds a dead space capacity, a measuring vale passage 9 forming a part of an expired air discharge route 2 is separated from the expired air discharge passage 2 and integrated into an expired air measuring route 3 continued to a carrier gas supplying part 14, and an expired air sample S within the measuring valve passage 9 is sent to a column 15 together with a carrier gas to separate a specified gas component. The specified gas component is detected by a detector 16, and its detection signal is outputted to a microcomputer 41 and arithmetically processed. Further, the concentration of the specified gas component is calculated from a preliminarily stored calibration curve, and stored as clinical inspection data.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a clinical test method and apparatus using breath as a specimen, and to reduce the concentration of a small amount of a gas component contained in a breath sample of a subject to a non-selective and relatively large sample. The present invention relates to a method for reliably excluding a dead space portion from exhaled breath exhaled by a subject when performing measurement using a detector that requires exhalation, and for collecting exhaled breath samples simply, reliably and accurately for analysis.

[0002]

2. Description of the Related Art Expiration is emitted continuously and intermittently as long as a person (or animal) is sustaining life.
In addition, since a trace amount of volatile components in mixed venous blood flowing through the alveoli capillaries move into exhalation by gas exchange, it is presumed that there is a correlation between exhalation and blood with respect to volatile components. In addition, it is possible to separately measure volatile components, which is difficult in blood analysis, and since it is non-invasive unlike blood, it can be said that breath is ideal as a specimen for clinical biochemical tests.

[0003] However, conventionally, breath has not been used as a specimen for clinical biochemical examination at all. This is because, firstly, there is a preconceived opinion that breathing cannot be a specimen for clinical biochemical tests, and secondly, the gas to be detected in breathing has an extremely low concentration (at most ppm in ppb unit).
Unit), and therefore, can only be measured by a combination of a trace component concentrating device and a large-sized high-sensitivity gas detecting device. Therefore, the measurement is performed only in the laboratory where the skilled person operates special equipment and tools, and there are only a few reports of clinical tests.

[0004] Moreover, even if the exhaled breath is collected in a container, it takes space for storage and transportation, and some of the gas components are unstable. It is not easy to carry out the analysis with. Therefore, clinical biochemical tests using breath as a sample are inevitably face-to-face, and bedside tests, prehospital tests in ambulances, screening tests during medical treatment,
Further, it is considered that the method is effectively used only when the measurement person (analyst) and the subject (patient) face each other, such as monitoring the condition of a patient (continuous monitoring).

[0005] Therefore, as described above, an apparatus combining a concentrator and a large-sized high-sensitivity gas detector which is performed on a part of a laboratory scale is practically useless, and is small, portable and highly sensitive. Inspection devices that are easy to operate, yet have excellent safety and quick measurement are required. Of course, data reliability and economy are also required. Furthermore, since it is conceivable that moisture in the exhaled breath may condense on the wall of the container and dissolve and adsorb a small amount of gas components, the exhaled breath is directly sucked from the subject (patient) into the testing device and used for measurement. Is preferred.

[0006]

SUMMARY OF THE INVENTION From such a viewpoint,
The present inventors have conducted intensive studies to establish a clinical testing technique using breath as a specimen, and have developed a highly sensitive PID for a detector.
(Photo Ionization Detector: Photo Ionization Detector)
1).

However, this device employs a configuration in which exhaled air is forcibly sucked by a pump and discharged out of the system. Therefore,
Since the exhalation is aspirated while the exhalation is small or stopped, there is a possibility that an air component may be mixed in the exhaled breath sample. In addition, since the removal of the dead space is controlled by the rotation time of the pump, there is a possibility that the expired air from the dead space may be mixed into the breath sample for the same reason. Furthermore, a three-way solenoid valve is provided at two places during the discharge of exhaled air out of the system,
The interval between them is the sample measuring section. However, since the photoionization detector requires only a small amount of exhaled breath sample, the exhalation discharge tube must be narrowed, and therefore, there is a problem that it takes time to eliminate exhaled breath in the dead space.

[0008] The dead space is a dead space, and the expiration in this portion is a mixture of “exhalation” from the alveoli and the inhaled “atmosphere”. (Alveolar air samples). The dead space volume is approximately 150-200 ml for adults and the first insufflation (initial expiration) must not be treated as a sample and must be discarded. That is, the reliability of the breath sample cannot be obtained unless it is the end breath excluding this.

[0009]

In view of the above, the present inventors have found that exhalation of the dead space is reliably eliminated, and that a relatively large amount of exhaled breath sample can be accurately weighed from exhaled exhaled air. The present invention has been completed as a result of intensive studies aimed at developing a method and an apparatus for analyzing a specific gas component in exhaled breath that can be reliably performed, has a simple structure, and can be reduced in cost. Hereinafter, the present invention will be described in detail.

The analyzer of the present invention employs human breath as a specimen, and separates and measures trace chemical substances in the breath breathed by the subject to obtain various clinical biochemical information.

The analyzer of the present invention (a device for analyzing a specific gas component in exhaled breath) is roughly divided into an exhaled breathing route for naturally exhaling the exhaled breath blown from a mouthpiece, and a breathing measurement route for analyzing a weighed breath sample. And an arithmetic processing unit. The exhalation discharge path is composed of an exhalation collection tube having an inner wall heating function and a mouthpiece attached to the tip, and an exhalation discharge tube incorporating a weighing valve path of a weighing valve and a flow sensor. The breath measurement path includes a carrier gas supply section, a weighing valve path of a weighing valve, a column, a detector, and a pipe connecting these. Here, the weighing valve is incorporated in both paths in common, and the weighing valve path is alternately switched to both paths.
The weighing valve, the exhalation discharge pipe, the column, the detector, and the pipeline connecting these are housed in a thermostat. As a detector, it requires a non-selective and relatively large sample,
In other words, a low-sensitivity metal oxide semiconductor sensor, a contact combustion type sensor, or the like is used. Further, the arithmetic processing unit performs monitoring of the flow sensor, switching of the weighing valve path, storage of the calibration curve, and calculation and storage of the concentration of the specific gas component.

Next, the inside of the breath collection tube of the breath measurement path is equal to or higher than the body temperature, for example, 36 to 100.
C., more preferably about 40 to 50.degree. This is to prevent the moisture in the exhaled breath from condensing and adhering to the inner wall of the exhalation collection tube and dissolving and adsorbing the gas component there. To warm up,
A heating element may be arranged around or inside the breath collection tube, or the tube itself may be formed of a material having heat generation, and the outer periphery thereof may be covered with a heat insulating material. Further, a temperature control mechanism may be incorporated. If the inner diameter of the exhalation collection tube is too small, a feeling of resistance to inhalation of exhalation occurs, and if it is too large, turbulence occurs inside and the exhalation in the dead space mixes with the end exhalation or the weighing valve path becomes too short. Therefore, the inner diameter of the breath collection tube is preferably about 4 to 20 mmφ, more preferably 6 to 10 mmφ. In addition, the outer diameter is 3
About 10 to 10 mm. If the mouthpiece attached to the breath collection tube is of a disposable type, it is sanitary.

The exhalation discharge tube is connected to the exhalation collection tube via a weighing valve at substantially the same inside diameter as the exhalation collection tube, and incorporates a flow sensor therein. The flow sensor is
It measures the volume of expiration that is spontaneously exhaled, and may be a device that can directly measure the volume of expiration or a device that measures the outflow rate of exhalation. In the latter case, the expiratory volume is determined from the cross-sectional area of the exhalation discharge tube.

The weighing valve is provided with a weighing valve path that is alternately switched between an exhalation discharge path and an exhalation measurement path, and a bleeding sample is collected by the weighing valve path. Switching of the weighing valve path is performed by various types of driving methods such as a sliding type and a rotary type. The inner diameter of the weighing valve is preferably about the same as the inner diameter of the breath collection tube, but the volume of the breath sample (0.
(5 to 10 ml) may be slightly thinner or thicker. Incidentally, when the inner diameter of the weighing valve path is 6 mm, if the length is set to 17.7 mm, the internal capacity becomes about 0.5 ml. However,
In order to make the internal capacity 10 ml with this inner diameter, a valve path as long as 35 cm is required. Therefore, when the capacity is large, the inner diameter may be increased or a sample loop connected to the weighing valve path may be provided outside the valve. When the weighing valve path is switched from the exhalation discharge path to the exhalation measurement path, the connection between the exhalation collection pipe and the exhalation discharge pipe is cut off, so that exhalation cannot be inhaled, and the subject is shocked. In order to avoid this, when the weighing valve path is switched to the breath measurement path, a similar bypass may be provided at the original weighing valve path position.

On the other hand, the breath measurement path includes a carrier gas supply section, a weighing valve path of a weighing valve, a column, a detector, and a pipe connecting these. The carrier gas supply unit sends out a carrier gas for sending the breath sample to the separation column, and a small gas cylinder is preferable as a supply source in view of the portability of the present inspection apparatus. However, in the case where this inspection device is installed and used in a certain place,
Large gas cylinders can also be used. Inexpensive clean air or nitrogen gas can be used as the carrier gas, but helium or any other commonly used gas can be used. In the case of clean air, atmospheric air may be supplied by a compression pump without packing in a gas cylinder. However, in order to eliminate the influence of a trace amount of gas components in the atmosphere, it is necessary to clean the air with an air filter incorporating an adsorbent or the like.

The detector used in the present invention is a gas sensor such as a metal oxide semiconductor sensor or a contact combustion type sensor. These gas sensors require a relatively large amount of sample due to their somewhat low sensitivity. The amount of the sample depends on the type and concentration of the gas component in the expiration and the type of the gas sensor.
It may be about ml. Further, since these gas sensors are non-selective, if they are separated by a column, various exhaled gas components, for example, lower saturated hydrocarbons such as hydrogen, acetone and methane, ethyl alcohol, acetaldehyde and the like can be measured. Since the column has a relatively large amount of breath sample, a packed column is usually used, but a capillary column can also be used depending on the sample amount and gas components. If a plurality of exhaled gas components can be separated by the column, a plurality of gases to be detected can be measured. In addition, including the separation column, the weighing valve, the exhalation discharge pipe, the detector, these connecting conduits,
It is stored in a constant temperature bath to prevent condensation of moisture in the exhaled breath and, like the exhalation collection tube, 36 to 100 ° C, more preferably 40 to 40 ° C.
It is better to keep the temperature at about 50 ° C.

A main part of the arithmetic processing unit is a microcomputer, which receives a measurement signal output from the detector, performs an arithmetic process, calculates a concentration of a gas component to be detected from a calibration curve stored in advance, and performs a clinical test. Store as data. In addition, monitoring of the flow sensor and switching of the weighing valve path, furthermore, display device (display) and recording device (printer)
It manages the operation program of the entire device, such as outputting a signal to an output device or accepting an input signal from a keyboard.

Next, the sensitivity calibration of the analyzer will be described. Since the analyzer of the present invention targets a gas body for measurement, the measured value may be influenced by other variables even if the measured value is housed in a thermostat. That is, the measured value may fluctuate from the true value due to various factors such as a change over time of the column or the detector or a variation in the operation of the detector. Therefore, it is desirable to adjust the sensitivity at the start of measurement every day or at an appropriate time. Of these, the zero point adjustment is performed by supplying a carrier gas to the breath measurement path. On the other hand, sensitivity adjustment is performed using a high-purity nitrogen gas (standard gas) containing a predetermined concentration of a gas component to be measured. That is, the weighing valve path of the weighing valve is incorporated into a standard gas supply path connected to the standard gas supply unit, and the weighing valve path is suction-filled with a standard gas having a known concentration, and then the weighing valve path is separated from the standard gas supply path to measure breath. The standard gas concentration is measured by incorporating it in the path, and the analytical value is calibrated. The three-point correction may be performed using two kinds of standard gases having low and high concentrations. Therefore, the weighing valve is configured such that the weighing valve path can be switched between an exhalation discharge path, an exhalation measurement path, and a standard gas supply path, and the switching is performed according to an instruction of the arithmetic processing unit. Although the standard gas can be blown into the exhalation discharge path, there is a drawback that the standard gas is consumed in large quantities.

In using the test apparatus of the present invention having the above-described configuration, the subject first puts a mouthpiece attached to the breath collection tube into his / her mouth and confirms a measurable state or presses a measurement start button. Inhale exhalation.
Exhaled air is discharged out of the system through an exhalation discharge pipe. At the stage when the amount of exhaled air substantially equal to or greater than the dead space volume (about 150 to 200 ml) is exhaled, the weighing valve path of the weighing valve exhales. The path is switched to the breath measurement path. The breath sample in the weighing valve path is sent to the column together with the carrier gas to separate the specific gas component, and the specific gas component is detected by the detector. The output of the detector is subjected to arithmetic processing by an arithmetic processing unit. Here, the concentration of the specific gas component to be detected is calculated from a calibration curve stored in advance and stored as clinical test data or a signal is output to an output device. . One measurement is completed in a few minutes, depending on the type of gas to be detected.
The concentration of one or a plurality of specific gas components in exhaled air can be measured quickly and accurately. In the calibration of the analyzer, the weighing valve path of the weighing valve is incorporated into the breath measurement path, and the carrier gas flows, and the measured value at that time is set to zero. In addition, the weighing valve path of the weighing valve is incorporated in the standard gas supply path, a standard gas having a known concentration is sampled, and the measured value at that time is calibrated to the standard gas concentration.

[0020]

Next, the present invention will be described in more detail with reference to the preferred embodiments shown in the drawings. However, the present invention is not limited to those shown in the drawings. FIG. 1 shows an example of a block diagram of an apparatus 1 for analyzing a specific gas component in breath according to the present invention. This analyzer 1 has an expiratory discharge path 2
, A breath measurement path 3, an arithmetic processing unit 4, an input / output device, and the like. Most of the exhalation discharge path 2 and the exhalation measurement path 3 are housed in the thermostat 5. FIG. 2 is a schematic view partially showing an example of an exhalation discharge path including a weighing valve, and FIG. 3 is a schematic view partially showing another example of an exhalation discharge path including a weighing valve.

The exhalation discharge passage 2 is provided with an exhalation collection tube 7 having an inner wall heating function and a mouthpiece holder 6 fixed at the end.
And an exhalation discharge pipe 11 incorporating a weighing valve passage 9 of a weighing valve 8 and a flow sensor 10. Symbol 12 is
It is a disposable mouthpiece. Breath collection tube 7
Is a Teflon tube having an inner diameter of about 3 to 8 mm and a length of about 1 m covered with a heater and a heat insulating material. The inside of the Teflon pipe is heated to prevent adhesion of moisture in the exhaled breath. The heating is performed by adjusting an arbitrary temperature of 36 to 100 ° C., for example, 50 ° C. by a controller.

The weighing valve 8 is configured such that the weighing valve passage 9 slides and is alternately switched between the exhalation discharge path 2 and the exhalation measurement path 3. Depending on the volume of the breath sample,
A sample loop may be provided outside the valve. The inner diameter of the weighing valve path is about 4 to 20 mm like the inner diameter of the breath collection tube, but may be somewhat thinner or thicker depending on the volume of the breath sample. When the inner diameter of the weighing valve path is 5 mm and the length is 50 mm, about 1 ml of a breath sample can be collected. The weighing valve 8 is not limited to a slide type, and any type can be used as long as the weighing valve path 9 is freely switchable.

The exhalation discharge tube 11 is connected to the exhalation collection tube through a weighing valve at substantially the same inside diameter as the exhalation collection tube 7, and incorporates the flow sensor 10 therein. When it is detected by the flow rate sensor 10 that about 150 to 200 ml of exhaled air has been exhausted, the exhalation discharge path 2 and the exhaled air measurement path 3 are switched. This is for the purpose of removing exhaled breath from the dead space of the subject, but also has the meaning of preventing contamination with the exhaled breath of another subject measured immediately before.

Since one adult breaths about 1 liter in an adult, if the weighing valve is suddenly switched, as shown in FIG. Insufflation may not be possible, and the subject may be shocked. FIG. 2A shows a state at the time of exhalation discharge, and FIG.
(B) shows the state at the time of breath measurement. In order to avoid this problem, for example, as shown in FIG. 3, when the weighing valve path 9 is switched to the breath measurement path 3, it is preferable to provide a bypass valve path 13 that comes to the original position of the weighing valve path. FIG. 3A shows a state at the time of exhalation discharge, and FIG. 3B shows a state at the time of exhalation measurement. Alternatively, when the expiratory discharge resistance increases (see FIG. 2).
In (b)), the subject may be instructed to stop the call.

Next, the breath measurement path 3 includes a carrier gas supply section 14, a weighing valve path 9 of a weighing valve 8, a column 15, a detector 16, and pipes 17 and 18 connecting these. The carrier gas supply unit 14 sends out a carrier gas for sending a breath sample to a separation column, and includes a small gas cylinder 19 containing clean air and the like and a carrier gas delivery pipe 20. The carrier gas delivery pipe is connected to an electromagnetic valve 21. It is connected. The weighing valve path 9 is used for the exhalation discharge path 2.
And is common.

As the detector 16, a general-purpose gas sensor, such as a metal oxide semiconductor sensor or a contact combustion type sensor, capable of measuring a trace component in the breath requiring measurement, for example, hydrogen, acetone, methane or the like is used. Therefore, the breath sample is separated by a column (packed column, capillary column) and supplied to the detector 16. The weighing valve 8, the exhalation discharge pipe 11, the detector 16, and the connecting lines 17 and 18, including the column 14, are housed in the thermostat 5 to prevent condensation of moisture in the exhaled air. Keep the temperature at about 40-50 ° C.

The standard gas supply path 22 is for calibrating the sensitivity of the analyzer, and as shown in FIGS. 1 and 2, the standard gas supply section 23, the weighing valve path 9 of the weighing valve 8, and the weighing valve path. 9 comprises a suction pump 24 for sucking and dispensing the standard gas. The standard gas supply unit 23 includes a standard gas cylinder 25 and a standard gas delivery pipe 26, and the standard gas delivery pipe 26 is connected to an electromagnetic valve 27. That is, the weighing valve 8 is configured such that the weighing valve path 9 is switched between the exhalation discharge path 2, the exhalation measurement path 3, and the standard gas supply path 22. This switching is performed according to an instruction from the arithmetic processing unit.

The main part of the arithmetic processing unit 4 is a microcomputer 41, which receives the measurement signal output from the detector 16, performs an arithmetic processing, and calculates the concentration of the gas component to be detected from a previously stored calibration curve. And store it as clinical test data. Further, it instructs the monitoring of the flow rate sensor 10, the switching of the weighing valve path 9, and the opening and closing of the electromagnetic valve 21 for delivering the carrier gas. Further, a display device (display) 28,
It manages an operation program of the entire apparatus, such as outputting a signal to an output device such as a printer or a recording device (printer) 29 and accepting an input signal from the keyboard 30.

Next, the sorting operation of the apparatus of the present invention will be described with reference to FIG. First, after confirming the measurable state (standby state), the subject is caused to hold the mouthpiece and exhalation B is exhaled. When expiration is exhaled (exhaled) in an amount corresponding to the capacity of the dead space portion of the expiration (the state shown in FIG. 2A), the weighing valve path 9 of the weighing valve 8 changes the expiration discharge path 2.
Is switched to the breath measurement path 3, and the breath sample S is weighed. The breath sample S in the weighing valve path is sent to the column 15 together with the carrier gas C, is separated and fractionated by the difference in the retention time of each component gas, sequentially reaches the detector 16, and detects necessary gas components. (Figure 2
(State of (b)). The output from the detector 16 is subjected to arithmetic processing by the arithmetic processing device 4, and here, the concentration of the specific gas component to be detected is measured from a previously stored calibration curve. The measurement ends about 5 minutes after the start of exhalation. In the sensitivity calibration of the analyzer, as shown in FIG. 2C, the weighing valve path 9 of the weighing valve 8 is incorporated in the standard gas supply path 22, and the standard gas St is suction-filled into the weighing valve path 9. Next, the measurement is performed by switching the weighing valve path 9 to the breath measurement path 3 (the state shown in FIG. 2D).

However, in the case of the configuration shown in FIG. 2, the expiration cannot be discharged when the weighing valve line 9 is switched. Therefore, as shown in FIG. 3, when the weighing valve path 9 is switched to the expiration measurement path 3, a bypass valve path 13 that comes to the position of the original weighing valve path may be provided in the weighing valve 8. FIG.
(A) shows the state at the time of exhalation discharge, and FIG. 3 (b) shows the state at the time of exhalation measurement. However, the standard gas supply path is omitted for the sake of simplicity. The drawings corresponding to FIGS. 2C and 2D are also omitted.

Next, FIG. 4 shows the analysis of the hydrogen gas concentration in the breath sample using a metal oxide semiconductor sensor (manufactured by Figaro, TGS-813) as a detector and clean air (20 ml / min) as a carrier gas. The results are shown. In this breath analysis, a test subject (male, 45 years old) was ingested with an aqueous lactulose solution (12.5 g of lactulose: 400 ml of water), and the hydrogen concentration (ppm) in the breath was measured every 30 minutes for 14 hours immediately after ingestion. The results obtained are shown (solid line graph). Lactulose is an oral medicine for the treatment of hyperammonemia, and generates hydrogen gas during the reaction with bacteria in the intestinal tract. Therefore, a high concentration of hydrogen gas in the breath can be an indicator that lactulose is degraded in the intestinal flora, acetic acid is produced as an end product, and the efficacy is obtained. The dotted line graph in the figure indicates that the same subject was taken on a different day and ingested a sucrose solution (60 g of sucrose: 200 ml of water) (simultaneously with bacon, eggs, and black tea), and every 30 minutes for 14 hours immediately after ingestion. Shows the results of measuring the hydrogen concentration in the exhaled air. In this case, there is almost no change in the hydrogen gas concentration in the breath. The concentration of hydrogen gas in the breath of a normal person is about 10 ppm.

[0032]

As described above, according to the present invention, the exhalation inhaled from the mouthpiece is discharged while being measured by the flow rate sensor provided at the outlet side of the exhalation discharge path, and the exhaled amount exceeds the dead space capacity. Then, the weighing valve path of the weighing valve is separated from the exhalation discharge path and incorporated into the exhalation measurement path to collect an exhalation sample, and a small amount of exhalation gas component to be measured is separated by a column and detected by a gas sensor to measure the concentration. Things. Therefore, it has the following features. 1) Since the measurement operation only causes the mouthpiece to spontaneously exhale in the standby state, even an unfamiliar subject can measure without malfunction. Also, there is no need to provide special training to the practitioner, and no special operator is required. Even if a new test is routinely performed, there is no burden on medical staff. In addition, since the measurement result is determined in a short time and the data is automatically recorded, it is possible to immediately respond to medical treatment. 2) Since the exhaled breath is automatically sampled at a stage beyond the dead space volume, the dead space portion is reliably excluded from the exhaled breath sample, and accurate analysis is possible. 3) Since sampling is performed simply by switching the weighing valve path of the weighing valve from the exhalation discharge path to the exhalation measurement path, the mechanism is simple and accurate and reliable sampling of the exhalation sample can be performed, enabling accurate analysis. Becomes 4) By incorporating the standard gas supply path, calibration of the analyzer can be performed accurately and reliably. 5) Since the inner wall of the exhalation collection tube is heated, there is no loss of trace components in the exhalation, and accurate measurement values can be obtained with good reproducibility. 6) As the device is downsized, as a bedside device,
In addition, it can be used anywhere, as an on-board device such as an ambulance. Further, the measurement result is quickly (approximately several minutes) determined and recorded, so that it can be used immediately as medical data, thereby expanding the application range in practical medical care. 7) Since the device has a simple component configuration, it can be manufactured at low cost. Also, since the consumables are about the same as the column packing material, the measurement cost is extremely low. 8) Exhaled breath is a non-invasive sample, and does not give the subject any physical, mental pain, fear, or oppression. Also, there is no need to worry about infection by blood. Therefore, the burden on the subject can be completely eliminated in repeated measurement such as a load test or continuous observation using a monitor during treatment. Moreover, since the test results can be obtained immediately, it is inevitable that the disease can be detected early. 9) In the case of exhaled breath, measurement results can be obtained much more easily and quickly than in blood, and there is more accurate information than in non-invasive non-invasive clinical test methods such as urine, saliva, and sweat. May increase rapidly. As a result, the measurement of a specific gas, which was unknown until now, will be useful for diagnosis of new diseases, etc. In addition, it is expected that it will make a great contribution to medicine, such as elucidating unknown phenomena that cannot be predicted at this time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an apparatus for analyzing a specific gas component in breath according to the present invention.

FIGS. 2A and 2B are schematic diagrams partially showing an example of an exhalation discharge path including a weighing valve. FIG. 2A shows a state at the time of exhalation discharge, and FIG. 2B shows a state at the time of exhalation measurement. (C) shows a state at the time of standard gas suction, and (b) shows a state at the time of breath measurement.

FIGS. 3A and 3B are schematic diagrams partially showing another example of the exhalation discharge path including a weighing valve, wherein FIG.
Indicates the state at the time of breath measurement.

FIG. 4 is a graph showing fluctuations in exhaled hydrogen gas level due to differences in intake.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Specific gas component analyzer in exhalation 12 Mouthpiece 2 Exhalation discharge path 14 Carrier gas supply unit 3 Exhalation measurement path 15 Column 4 Arithmetic processing unit 16 Detector 7 Exhalation collection tube 22 Standard gas supply path 8 Weighing valve B Exhalation 9 Weighing Valve path S Breath sample 10 Flow sensor C Carrier gas 11 Breath discharge pipe St Standard gas

Claims (8)

[Claims] An exhaled breath exhaled by a subject is weighed in a state where the exhaled breath is heated to a body temperature or a higher temperature, and the weighed exhaled breath sample is supplied to a detector together with a carrier gas, and a specific gas component in the breath sample is measured. In the case of measuring the concentration of exhaled breath, the exhaled breath blown from the mouthpiece is discharged while being measured by a flow sensor provided on the outlet side of the exhaled discharge path. The weighing valve path of the weighing valve that forms a part is separated from the exhalation discharge path and incorporated into the exhalation measurement path connected to the carrier gas supply unit, and the exhalation sample in the weighing valve path is sent to the column together with the carrier gas to separate specific gas components. Then, a specific gas component is detected by a detector that requires a large amount of sample in a non-selective manner, and the signal is arithmetically processed by an arithmetic processing unit and stored in advance. A method for analyzing a specific gas component in expiration, comprising calculating a concentration of a specific gas component from a line, storing the concentration as a clinical test data, or outputting a signal to an output device. 2. If necessary, a weighing valve line of a weighing valve is incorporated into a standard gas supply path connected to a standard gas supply section, and the weighing valve path is filled with a standard gas having a known concentration by suction. 2. The method for analyzing a specific gas component in expiration according to claim 1, wherein the calibration is performed by measuring the standard gas concentration by incorporating the gas into the expiration measurement path separately from the gas supply path. 3. The method according to claim 1, wherein the dead space volume is 150 to 200 ml. 4. The volume of the breath sample is 0.5 to 10 ml.
The method for analyzing a specific gas component in exhaled breath according to claim 1, wherein: 5. An exhalation discharge path for naturally exhaling exhaled air blown from a mouthpiece, an exhalation measurement path for analyzing a weighed exhaled breath sample, and an arithmetic processing unit, wherein the exhalation discharge path includes an inner wall heating. It is composed of an exhalation collection tube equipped with a function and a mouthpiece attached to the tip, and an exhalation discharge tube incorporating a weighing valve path and a flow rate sensor of a weighing valve. The exhalation measurement path is a weighing valve of a carrier gas supply unit and a weighing valve. Channel, a column, a detector, and a line connecting them, and the weighing valve is configured such that the weighing valve line is alternately switched to an exhalation discharge path and an exhalation measurement path. , Columns, detectors and the pipeline connecting them are housed in a thermostat, and the processing unit monitors the flow sensor, switches the weighing valve path, and stores and specifies the calibration curve. An apparatus for analyzing a specific gas component in exhaled air, which calculates or stores the concentration of a gas component. 6. The weighing valve has a weighing valve path that can be switched between an exhalation discharge path, an exhalation measurement path, and a standard gas supply path, and the standard gas supply path is weighed by the standard gas supply unit and the weighing valve. 6. The apparatus for analyzing a specific gas component in expiration according to claim 5, comprising a valve path and a suction device for suctioning a standard gas into the weighing valve path. 7. The apparatus according to claim 5, wherein the weighing valve is a slide type or a rotary type, and the weighing valve path includes a sample loop provided outside the valve. 8. The apparatus according to claim 5, wherein the detector is a metal oxide semiconductor sensor or a catalytic combustion type sensor.