JP4028006B2 - Analyzer for specific gas components in exhaled breath - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a clinical test method and apparatus using exhaled breath as a specimen, and a case where a minute amount of gas component concentration contained in a breath sample of a subject is measured using a non-selective small and highly sensitive detector. The present invention relates to a device that reliably excludes a dead space from exhaled breath that a subject calls and collects a small amount of exhaled sample simply, reliably and accurately for analysis.
[0002]
[Prior art]
Exhalation is one that is continuously and intermittently released as long as a person (or animal) maintains life. Moreover, since a small amount of volatile components in the mixed venous blood flowing through the alveolar capillaries move into exhaled gas by gas exchange, it is presumed that there is a correlation between exhaled air and blood with respect to the volatile components. In addition, since it is possible to perform differential measurement of volatile components, which is difficult in blood analysis, and it is non-invasive unlike blood, exhaled breath can be said to be an ideal sample for clinical biochemical examination.
[0003]
However, exhalation has not been used so far as a specimen for clinical biochemistry. This is due to the preconception that the exhaled breath should not be a sample for clinical biochemistry, etc., and secondly, the target gas in the exhaled breath is extremely low (ppb units at most ppm) Therefore, it is possible to measure for the first time by a combination of a concentration device for trace components and a large high-sensitivity gas detection device. Therefore, the measurement is performed only in a laboratory in which an expert operates special equipment and tools, and there are only a few clinical research reports.
[0004]
In addition, even if the exhaled air is collected in a container, it takes a place for storage and transportation, and some gas components are unstable, so unlike the blood, it is transported to an analysis center etc. and analyzed with a large device. It is not easy to do. Therefore, clinical biochemical tests using breath as a specimen inevitably face-to-face, such as bedside tests, prehospital tests in ambulances, screening tests during medical treatment, and patient status monitoring (continuous monitoring). It seems to be used effectively only when the measurer (analyst) and the subject (patient) measure face-to-face.
[0005]
Therefore, as described above, an apparatus combining a concentrator and a large-scale high-sensitivity gas detection apparatus performed on some laboratory scales is not practically useful, and is small, portable, and highly sensitive while operating. An inspection apparatus that is simple and excellent in safety and measurement speed is required. Of course, data reliability and economic efficiency are also required. In addition, the moisture in the breath can be condensed on the wall of the container to dissolve and absorb a small amount of gas components, so that the breath is directly sucked from the subject (patient) into the testing device and used for measurement. Is preferred.
[0006]
[Problems to be solved by the invention]
From such a point of view, the present inventors have intensively studied to establish a clinical laboratory technique using breath as a specimen, and used a highly sensitive PID (Photo Ionization Detector) as a detector. An exhalation analyzer was developed (Japanese Patent Laid-Open No. 5-160341).
[0007]
However, this apparatus has a configuration in which exhaled air is forcibly sucked by a pump and discharged out of the system. Accordingly, since the breath is sucked even when the breath is little or stopped, the breath sample may be mixed with atmospheric components. Moreover, since the removal of the dead space part is managed by the rotation time of the pump, there is a possibility that the exhaled air in the dead space part may be mixed into the exhaled sample for the same reason. Furthermore, a three-way electromagnetic valve is provided at two locations in the middle of discharging exhalation out of the system, and the space between them is used as a sample measuring section. However, since the photoionization detector requires only a small amount of exhalation sample, the exhalation discharge tube has to be thin, and thus there is a problem that it takes time to eliminate exhalation in the dead space.
[0008]
The dead space is the dead space, and the exhaled air in this part is a mixture of “exhaled air” from the alveolar air and the inhaled “atmosphere”. ) Cannot be treated as. The dead space volume is about 150-200 ml for adults, and the first insufflation part (initial exhalation) must not be handled as a sample and must be discarded. In other words, the exhalation sample cannot be reliable unless it is the end exhalation excluding this.
[0009]
[Means for Solving the Problems]
From the above point of view, the present inventors reliably exhale exhalation in the dead space portion, and can accurately and accurately collect a small amount of exhalation sample from exhaled exhalation, and have a simple structure and low cost. As a result of earnest research aimed at developing a method and apparatus for analyzing a specific gas component in exhaled air that can be converted into a breath, the present invention has been completed. Hereinafter, the present invention will be described in detail.
[0010]
The analyzer of the present invention employs human breath as a specimen, and separates and measures a trace amount of chemical substance in breath exhaled by a subject to obtain various clinical biochemical information.
[0011]
The analyzer of the present invention (analyzer for a specific gas component in exhaled breath) is roughly divided into an exhalation exhaust path for naturally exhaling exhaled breath from the mouthpiece, and an exhaled breath sample from the middle of the exhaled exhaust path. It comprises an exhalation suction path to be taken, an exhalation measurement path for analyzing a weighed exhalation sample, and a 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 flow sensor. The exhalation suction path is composed of a weighing valve path of a weighing valve connected in the middle of the exhalation discharge path and a suction device for sucking an exhalation sample into the weighing valve path. The expiration measurement path is composed of a carrier gas supply unit, a weighing valve path of a weighing valve, a column, a detector, and a pipe line connecting these. Here, the weighing valve is incorporated in both the exhalation suction path and the exhalation measurement path, and the weighing valve path is alternately switched to both paths. In addition, the exhalation exhaust pipe, the weighing valve, the column, the detector and the pipe line connecting them are housed in a thermostatic bath. The detector is a small high-sensitivity detector that outputs a measurement signal according to the amount of ionization by ionizing a minute amount of gas components by irradiation with ultraviolet rays or radiation, specifically, a photoionization detector (PID), ion transfer A degree spectrum detector (IMS), an electron capture ion detector (ECD), a flame ionization detector (FID), or a flame photometric detector (FPD) is used. The arithmetic processing unit also performs monitoring of the flow rate sensor, switching of the weighing valve path, storage of the calibration curve, calculation and storage of the concentration of the specific gas component, and the like.
[0012]
Next, it is desirable to heat the breath collection tube of the breath measurement path so that the inner surface thereof is equal to or higher than the body temperature, for example, 36 to 100 ° C., more preferably about 40 to 50 ° C. This is to prevent moisture in the exhalation from condensing and adhering to the inner wall of the exhalation collection tube and dissolving and adsorbing the gas component therein. In order to heat, a heating element may be disposed around or inside the breath collection tube, or the tube may be formed of a material having a heat generating property, and the outer periphery thereof may be covered with a heat insulating material. A temperature control mechanism may be incorporated. If the inner diameter of the exhalation sampling tube is too thin, a feeling of resistance will be generated in inhaling exhalation, and if it is too thick, turbulence will be generated inside, and exhalation in the dead space will be mixed with the end exhalation or the weighing valve path will be too short. Therefore, the inner diameter of the breath collection tube may be about 4 to 20 mmφ, more preferably 6 to 10 mmφ. The outer diameter is about 3 to 10 mm larger than the inner diameter due to a heat insulating material or the like. The mouthpiece attached to the breath collection tube is hygienic when it is of a disposable type.
[0013]
The exhalation discharge pipe is connected to the exhalation collection pipe through a weighing valve with substantially the same inner diameter as the exhalation collection pipe, and a flow sensor is incorporated therein. The flow sensor measures the amount of exhaled breath that is spontaneously called, and can be used to measure the exhaled amount directly or to measure the outflow rate of exhaled breath. In the latter case, the expiratory volume is determined from the cross-sectional area of the expiratory discharge pipe.
[0014]
The exhalation suction path is composed of a weighing valve path of a weighing valve connected in the middle of the exhalation discharge path and a suction device for sucking an exhalation sample into the weighing valve path. The connection between the exhalation discharge path and the weighing valve path of the weighing valve may be such that the weighing valve path is opened directly into the exhalation discharge path, or the suction path is branched from the middle of the exhalation discharge path and this suction path is used as the weighing valve path. You may connect. The weighing valve is incorporated in both the exhalation suction path and the exhalation measurement path, and the weighing valve path is alternately switched to both paths, and the exhalation sample is weighed and collected by this weighing valve path. The The weighing valve path is switched by various types of drive types such as a slide type and a rotary type. On the other hand, the breath sample is sucked by a suction device such as a suction pump or a syringe. However, this suction does not need to be accurately performed such as weighing, and it is only necessary to fill the weighing valve passage with the breath sample. Therefore, if the capacity of the weighing valve path is taken into consideration and suction is performed in excess of that capacity, an accurate exhalation sample weighing is automatically performed by the weighing valve path. When the required amount of suction is finished, the suction device is stopped. Since the volume of the breath sample is 10 to 1000 μl, more preferably 100 to 600 μl, the inner dimension of the weighing valve is determined accordingly. For example, if the inner diameter of the weighing valve path is 3 mm, the inner volume is about 140 μl when the length is 20 mm. If it is desired to lengthen the weighing valve path, a sample loop may be added to the outside.
[0015]
On the other hand, the breath measurement path includes a carrier gas supply unit, a weighing valve path of a weighing valve, a column, a detector, and a pipe line connecting these. The carrier gas supply unit sends out a carrier gas for sending the breath sample into the separation column, and a small gas cylinder is preferable as the supply source in view of the portability of the present inspection apparatus. However, a large gas cylinder can also be used when the inspection apparatus is installed and used at a certain location. Inexpensive clean air or nitrogen gas can be used as the carrier gas, but helium and other commonly used gases can be used. In the case of clean air, the atmospheric air may be supplied by a compression pump without filling the gas cylinder. However, in order to eliminate the influence of a trace amount of gas components in the atmosphere, it is necessary to clean with an air filter incorporating an adsorbent or the like.
[0016]
Detectors used in the present invention include PID (Photo Ionization Detector: photoionization detector), IMS (Ion Mobility Spectrometer: ion mobility spectrum detector), ECD (Electron Capture Detector: electron capture ion detector), FID ( Flame Ionization Detector (Hydrogen ion detector) or FPD (Flame Photometric Detector: Flame Photometric Detector), the target gas components in the breath are ionized by irradiation with light or radiation, etc. A type that outputs a measurement signal accordingly is used. These detectors are small and extremely sensitive, so only a small amount of sample is required. Among these, PID is the most preferable because it uses radiation and does not involve combustion of hydrogen gas. In addition, since these are all non-selective, if they are separated by a column, various exhaled gas components such as ketone bodies (mainly acetone), lower hydrocarbons such as methane, ethane, and pentane, ammonia, methyl mercaptan, and acetaldehyde. Etc. can be measured. Since the column has a very small amount of breath sample, a capillary column is usually preferable, but a packed column is also used depending on the sample amount. If a plurality of exhaled gas components can be separated in the column, a plurality of detection target gases can be measured. It should be noted that the weighing valve, exhalation exhaust pipe, detector, and these connecting pipes including the separation column are housed in a thermostatic bath in order to prevent moisture condensation in the exhalation, and the same as the exhalation collection pipe. The temperature may be kept at 100 ° C, more preferably about 40-50 ° C.
[0017]
The main part of the arithmetic processing unit is a microcomputer, which receives the measurement signal output from the detector, performs arithmetic processing, calculates the concentration of the gas component to be detected from a pre-stored calibration curve, and stores it as clinical test data To do. Also, the operation program for the entire device, such as monitoring the flow sensor and switching the weighing valve path, outputting signals to output devices such as display devices (displays) and recording devices (printers), and accepting input signals from the keyboard Manage.
[0018]
Next, sensitivity calibration (calibration) of the analyzer will be described. Since the analyzer of the present invention uses a gas body as a measurement object, the measured value may still be influenced by other fluctuation factors even if it is stored in a thermostat. That is, the measured value may deviate from the true value due to various factors such as a change with time of the column and the detector and variations in the operation of the detector. Therefore, it is desirable to adjust the sensitivity at the start of daily measurement or at an appropriate time. Of these, zero adjustment is performed by supplying a carrier gas to the breath measurement path. On the other hand, sensitivity adjustment is performed using high-purity nitrogen gas (standard gas) containing a predetermined concentration of the gas component to be measured. That is, the weighing valve path of the weighing valve is incorporated in the standard gas supply path connected to the standard gas supply unit, and the standard gas of known concentration is sucked and filled into the weighing valve path, and then the breath measurement is performed by separating the weighing valve path from the standard gas supply path. Incorporated into the path, the standard gas concentration is measured, and the analytical value is calibrated. The standard gas may be corrected at three points using low and high concentrations of two types. Therefore, the weighing valve is configured such that the weighing valve path is switched to the exhalation suction path, the exhalation measurement path, and the standard gas supply path, and the switching is performed according to an instruction from the arithmetic processing unit. The standard gas can be blown into the exhalation discharge path or sucked from the suction path of the exhalation suction path. However, the former consumes a large amount of standard gas, and the latter has a difficulty in complicating the configuration and operation, such as attaching a three-way cock to the branch part.
[0019]
In using the test apparatus of the present invention having the above-described configuration, first, (1) the mouthpiece attached to the breath collection tube is added to the mouth, the measurable state is confirmed or the measurement start button is pressed, Call exhalation. (2) Exhaled air is discharged out of the system through the exhalation discharge tube, but expired from the middle of the exhalation discharge route when the amount of exhalation corresponding to the dead space volume (about 150 to 200 ml) is exhausted. Aspirate the breath sample into the weighing valve path of the weighing valve that forms part of the suction path. (3) Subsequently, the weighing valve path is separated from the exhalation suction path and incorporated in the exhalation measurement path connected to the carrier gas supply unit. {Circle around (4)} The exhaled 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. (5) The output of the detector is arithmetically processed by an arithmetic processing unit. Here, the concentration of a specific gas component to be detected is calculated from a calibration curve stored in advance, and stored as clinical test data or signaled to an output device. Is output. One measurement is completed in a few minutes depending on the type of gas to be detected, and the concentration of a single gas component or a plurality of specific gas components in exhaled breath can be measured quickly and accurately. {Circle around (6)} The calibration of the analyzer is carried out by incorporating the weighing valve path of the weighing valve into the exhalation measurement path and allowing the carrier gas to flow and setting the measured value at that time to zero. In addition, the weighing valve path of the weighing valve is incorporated into the standard gas supply path, the standard gas having a known concentration is collected, and the measured value at that time is calibrated to the standard gas concentration.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in more detail based on a preferred embodiment shown in the drawings. The present invention is not limited to the illustrated one. FIG. 1 shows an example of a block diagram of an analyzer 1 for a specific gas component in exhaled breath according to the present invention. The analyzer 1 includes an exhalation discharge path 2, an exhalation suction path 3, an exhalation measurement path 4, an arithmetic processing unit 5, an input / output device, and the like. Most of the exhalation discharge path 2, the exhalation suction path 3, and the exhalation measurement path 4 are accommodated in a thermostatic chamber 6. FIG. 2 is a schematic diagram showing an example of an exhalation suction path including a weighing valve. FIG. 3 is a schematic diagram showing another example of an exhalation suction path including a weighing valve.
[0021]
The exhalation discharge path 2 includes an exhalation collection pipe 8 having an inner wall heating function and a mouthpiece holder 7 fixed at the tip and an exhalation discharge pipe 10 incorporating a flow sensor 9. Reference numeral 11 denotes a mouthpiece. The exhalation sampling tube 8 is a tube in which the outer periphery of a Teflon tube having an inner diameter of about 3 to 8 mm and a length of about 1 m is covered with a heater and a heat insulating material, and the inside is heated to prevent moisture from adhering to the exhalation. Heating is carried out by adjusting the temperature to an arbitrary temperature of 36 to 100 ° C., for example, 50 ° C.
[0022]
The exhalation discharge pipe 10 is connected to the exhalation collection pipe with substantially the same inner diameter as the exhalation collection pipe 8, and a flow sensor 9 is incorporated therein. When it is detected by the flow sensor 9 that about 150 to 200 ml of exhalation has been discharged, exhalation, which will be described later, is performed. This is for removal of exhalation in the dead space portion of the subject, but also has a meaning of preventing contamination with exhalation of other subjects measured immediately before.
[0023]
The exhalation suction path 3 branches the aspiration path 12 from the middle of the exhalation collection pipe 8 and the middle of the flow rate sensor 9 in the middle of the exhalation discharge path 2, preferably outside the constant temperature plexus. A weighing valve path 14 of the valve 13 and a suction pump 15 for sucking and collecting an exhalation sample are connected to the weighing valve path 14. A syringe may be used as the suction device. Since this suction only needs to suck and fill the exhalation sample into the weighing valve path, it is not necessary to accurately control the suction amount. Then, when the necessary amount of suction is finished, the suction device is stopped. On the other hand, since exhalation is unrelated to this suction, it can be performed as it is until the end.
[0024]
The weighing valve 13 is configured so that the weighing valve path 14 slides and is alternately switched between the exhalation suction path 3 and the exhalation measurement path 4. A breath sample is weighed and taken out by this weighing valve path. The inner dimension of the weighing valve path depends on the volume of the breath sample. When the inner diameter of the weighing valve path is 4 mm and the length is 20 mm, an exhalation sample of about 250 μl can be collected. Note that the weighing valve 13 is not limited to a slide type, and any other rotary type or any other type capable of freely switching the weighing valve path 14 can be used.
[0025]
Next, the breath measurement path 4 includes a carrier gas supply unit 16, a weighing valve path 14 of the weighing valve 13, a column 17, a detector 18, and pipe lines 19 and 20 connecting them. The carrier gas supply unit 16 sends out a carrier gas for sending a breath sample into the separation column. The carrier gas supply unit 16 is composed of a small air cylinder 21 containing clean air and a carrier gas delivery pipe 22, and the carrier gas delivery pipe is connected to an electromagnetic valve 23. It is lined up. The weighing valve path 14 is in common with the exhalation suction path 3.
[0026]
The detector 18 is a PID (photoionization detector), IMS (ion mobility spectrum detector), ECD (electron capture ion detector), FID (hydrogen flame ionization detector), or FPD (flame photometric detector). ), Etc., which are ionized by irradiating the gas component to be detected in the breath with light or radiation, and outputting a measurement signal in accordance with the ionization amount. These detectors are all small and extremely sensitive, but PID is the most preferable among them. However, since these detectors are non-selective, the breath sample is separated by a column (capillary column, packed column) and supplied to the detector 18.
[0027]
The standard gas supply path 24 is for calibrating the sensitivity of the analyzer. As shown in FIGS. 1 and 2, the standard gas supply path 24, the weighing valve path 14 of the weighing valve 13, and the weighing valve path 14 are standard. It comprises a suction pump 26 for sucking and fractionating gas. The suction pump 26 may also be used as the suction pump 15 in the exhalation suction path 3. The standard gas supply unit 25 includes a standard gas cylinder 27 and a standard gas delivery pipe 28, and the standard gas delivery pipe 28 is connected to an electromagnetic valve 29. That is, the weighing valve 13 is configured such that the weighing valve path 14 is switched to the exhalation suction path 3, the exhalation measurement path 4, and the standard gas supply path 24. This switching is performed according to an instruction from the arithmetic processing unit.
[0028]
With respect to the standard gas supply path 24, as shown in FIG. 3, the standard gas delivery pipe 28 is connected to the suction path 12 of the exhalation suction path 3, and the standard gas is weighed using the exhalation suction path 3. Good. Reference numeral 30 is a three-way valve.
[0029]
The main part of the arithmetic processing unit 5 is a microcomputer 51, which receives the measurement signal output from the detector 18, performs arithmetic processing, calculates the concentration of the gas component to be detected from a pre-stored calibration curve, and conducts a clinical test. Store as data. In addition, it instructs the monitoring of the flow sensor 9, the switching of the weighing valve path 14, and the opening and closing of the electromagnetic valves 23 and 29. Furthermore, the operation program of the entire apparatus is managed, such as outputting a signal to an output device such as a display device (display) 31 and a recording device (printer) 32, and receiving an input signal from the keyboard 33.
[0030]
Next, the sorting operation of the device of the present invention will be described with reference to FIG. First, after confirming the measurable state (standby state), the subject holds the mouthpiece and calls the exhalation B. When exhaled air corresponding to the volume of the dead space in the exhaled air is discharged (called), the exhaled air sample S is aspirated into the weighing valve path of the weighing valve that forms part of the exhalation suction path from the middle of the exhalation discharging path. To be taken (state of FIG. 2A). Meanwhile, the subject calls for exhalation to the end. The weighing valve path is switched to the breath measurement path, and the breath sample S in the weighing valve path is sent to the column 17 together with the carrier gas C, separated and fractionated by the difference in holding time of each component gas, and sequentially to the detector 18. The necessary gas components are detected. The output from the detector is arithmetically processed by an arithmetic processing unit, and here, the concentration of a specific gas component to be detected is measured from a calibration curve stored in advance. The measurement is completed about 5 minutes after the exhalation is called. In the sensitivity calibration of the analyzer, as shown in FIG. 2C, the weighing valve path 14 of the weighing valve 13 is incorporated into the standard gas supply path, and the standard gas St is sucked and filled into the weighing valve path 14. Next, the measurement valve path 14 is switched to the breath measurement path to perform measurement (state shown in FIG. 2D).
[0031]
The sorting operation of the apparatus of the present invention having a different standard gas supply path will be described with reference to FIG. In this apparatus, a standard gas delivery pipe 28 is connected to the suction path 12 via a three-way valve 30, and FIG. By switching the three-way valve 30 in the same state, standard gas can be sucked. FIG. 3B shows a state where the weighing valve path 14 is switched to the breath measurement path.
[0032]
FIG. 4 shows the concentration of acetone in the breath (ppm) and the blood ketone body concentration (acetoacetic acid + 3-OHBA: μmol / μm) in a total of 101 measurements in 3 days of fasting behavior of 3 adult males. It is a graph which shows the relationship with l). As can be seen from the figure, both show an excellent correlation (R = 0.970). For exhalation, 31.4 μl of exhalation sample was collected with the apparatus shown in FIG. 1 and analyzed using PID as a detector and clean air (20 ml / min) as a carrier gas. The blood ketone body concentration was measured by an enzymatic method (Ketrex / KETO340: manufactured by Sanwa Chemical Laboratory).
[0033]
【The invention's effect】
As described above, the present invention discharges the exhaled air blown from the mouthpiece while measuring it with a flow sensor provided on the outlet side of the exhaled air discharge route, and when the discharged amount exceeds the dead space capacity, The exhalation sample is aspirated into the weighing valve path of the weighing valve that forms part of the exhalation suction path, and then the weighing valve path is installed in the exhalation measurement path, and the trace exhalation gas component to be measured is separated by the column. The concentration is measured by detecting with a gas sensor.
Therefore, it has the following characteristics.
1) Since the measurement operation only allows the exhalation to be spontaneously called from the mouthpiece in the standby state, even an unaccustomed subject can measure without malfunction. In addition, it is not necessary to give special training to the practitioner, and no special operator is required, and even if it is routineized as a new examination, it does not burden the medical staff. In addition, the measurement results are found in a short time, and the data is automatically recorded, so that it is possible to respond immediately to medical care.
2) Since the exhaled breath is automatically sampled at a stage exceeding the dead space capacity, the dead space portion is surely excluded from the exhaled sample, and an accurate analysis becomes possible.
3) By connecting the exhalation suction path in the middle of the exhalation discharge path, a small amount of exhalation sample required by the detector can be easily collected in a state where the dead space portion is removed from the exhaled gas that is exhausted in large quantities.
4) Sampling is performed simply by switching the weighing valve path of the weighing valve from the exhalation suction path to the exhalation measurement path, so that the mechanism is simple and the exhalation sample can be collected accurately and reliably for accurate analysis. It becomes.
5) By incorporating the standard gas supply path, the analyzer can be calibrated accurately and reliably.
6) Since the inner wall of the breath collection tube is heated, there is no loss of trace components in the breath, and accurate measurement values can be obtained with good reproducibility.
7) Since the device is downsized, it can be used as a bedside device or an in-vehicle device such as an ambulance regardless of location. Furthermore, since the measurement results are quickly identified (several minutes) and recorded, they can be used as medical data immediately, expanding the range of practical medical applications.
8) Since the device has a simple component structure, it can be manufactured at low cost. In addition, since the consumable is about the same as the packing material of the column, the measurement cost is extremely low.
9) In addition, exhaled breath is a non-invasive specimen, and does not give physical or mental pain, fear or pressure to the subject. Moreover, there is no need to worry about blood infection. Therefore, the burden on the subject is completely eliminated in repeated observations such as stress tests and continuous observation such as monitoring during treatment. Moreover, since the test results can be obtained immediately, it is inevitably possible to detect the disease early.
10) Exhaled breath is much easier and faster than blood, and more accurate information than non-invasive non-invasive clinical testing methods such as urine, saliva and sweat. Examples can increase rapidly. As a result, the measurement of a specific gas, which has been unknown until now, is useful for the diagnosis and identification of new diseases, and it is thought that it will make a significant contribution to medicine, such as the elucidation of unknown phenomena that cannot be predicted at present.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an example of an analyzer for specific gas components in exhaled breath according to the present invention.
FIG. 2 is a schematic diagram partially showing an example of an exhalation suction path including a weighing valve, where (a) shows a state during exhalation and (b) shows a state during exhalation measurement. (C) shows the state at the time of standard gas suction, and (d) shows the state at the time of standard gas measurement.
FIGS. 3A and 3B are schematic views partially showing another example of an exhalation discharge path including a weighing valve, in which FIG. 3A shows a state during exhalation and FIG. 3B shows a state during exhalation measurement.
FIG. 4 is a graph showing the relationship between the acetone concentration (ppm) in exhaled breath and the blood ketone body concentration (acetoacetic acid + 3-OHBA: μmol / l).
[Explanation of symbols]
1 Analyzer for specific gas components in exhaled breath 16 Carrier gas supply unit
2 Exhalation pathway 17 columns
3 Expiratory aspiration path 18 Detector
4 Breath measurement route 24 Standard gas supply route
5 Arithmetic processing unit 25 Standard gas supply unit
8 Exhalation collection tube 26 Suction pump
9 Flow sensor B Exhalation
10 Exhalation tube S Exhalation sample
11 Mouthpiece C Carrier gas
12 Suction channel St Standard gas
13 Weighing valve
14 Weighing valve
15 Suction pump

Claims (1)

An exhalation discharge route that naturally discharges exhaled breath from the mouthpiece;
An exhalation suction path for weighing and sampling an exhalation sample from the exhalation discharge path;
Standard gas supply path for sensitivity calibration of the analyzer ,
Including an expiration measurement path for analyzing a weighed exhalation sample and an arithmetic processing unit,
The exhalation discharge path is composed of an exhalation collection pipe with a mouthpiece attached to the tip with an inner wall heating function and an exhalation discharge pipe incorporating a flow sensor,
The exhalation suction path is composed of a weighing valve path of a weighing valve connected in the middle of the exhalation discharge path and a suction device for sucking an exhalation sample into the weighing valve path,
The standard gas supply path is composed of a standard gas supply unit, a weighing valve path of the weighing valve, and a suction pump for sucking and separating the standard gas into the weighing valve path,
The breath measurement path is composed of a carrier gas supply unit and a weighing valve path of a weighing valve, a column, a detector, and a pipe line connecting these,
In addition, the discharge pipe, weighing valve, column, detector and the pipe connecting them are housed in a constant temperature bath, and the processing unit monitors the flow sensor, switches the weighing valve, stores the calibration curve, and the specified gas. The concentration of the component is calculated and stored, and the suction device operates after the flow sensor detects the passage of a certain amount, and the weighing valve has a weighing valve path that is an expiration suction path, an expiration measurement path, and A device for analyzing a specific gas component in exhaled breath, wherein the analyzer is switched to a standard gas supply path.

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