JPH1176202A - Stable isotope exhalation gas collecting method, and device to be used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable isotope exhalation gas collecting method and its device, by which only an alveolar gas of a third phase is collected, and a measurement of an accurate stable isotope ratio is made possible. SOLUTION: For this stable isotope exhalation gas collecting method, an exhalation gas from a person to be inspected is collected into a sealable flexible bag 2 through a mouthpiece by a closed system, and in addition, the exhalation gas is collected into a sealable exhalation gas collecting bag 6, and the exhalation gas in the bag 6 is collected into an exhalation gas collecting container 13. Also, a stable isotope exhalation gas collecting device is equipped with a mouthpiece attaching port l, the flexible bag 2 in a sealing box 3, which is connected to the mouthpiece attaching port 1, a regulating means 4 for an air pressure in the box 3, an exhalation gas collecting bag 6 in a sealing box 7, which is branched from a connection line between the attaching port 1 and the bag 2, and is provided with a pressure valve 5, a regulating means 8 for an air pressure in the box 7, and a collected gas discharging valve which discharges the exhalation gas in the bag 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting stable isotope expiratory gas and an apparatus for use in the method, and more particularly, the present invention can collect only phase 3 alveolar air. Therefore, the present invention relates to a stable isotope exhaled gas sampling method capable of accurately measuring a stable isotope ratio, and an apparatus used for the method.

[0002]

2. Description of the Related Art Conventionally, a method for measuring the stable isotope ratio of exhaled breath uses a stable isotope, ¹³ C, as a label, and exhales each exhaled gas before and after oral administration of the exhaled gas to in vivo. directly analyzed by mass spectrometry system, was calculated isotope exhaled gas _{^{(13 CO 2/12 CO 2}} ).

[0003]

In the conventional measuring method,
Before and after oral administration of ¹³ C label is a stable isotope, directly exhaled gas from in vivo was called each breath, and analyzed by mass spectrometry system, isotope expired gas _{^{(13 CO 2/12 CO 2}} ) Therefore, examinations and measurements could not be performed at hospitals and laboratories that do not have mass spectrometry systems.

In addition, when exhalation is collected in a bag, in the initial stage of exhalation, the air itself is exhaled instead of the alveolar air that has undergone gas exchange in the alveoli. Since the gas and the gas were mixed and the exhaled gas was collected in the bag, an error occurred in the measurement.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In particular, only the alveolar air is collected so that the air contained in the exhaled air and the carbon dioxide gas are mixed and the exhaled gas is not collected. Stable isotope that allows sampling and measurement results to be obtained at hospitals and laboratories that do not have a mass spectrometry system by collecting and bringing the exhaled gas collection bag to an organization that has a mass spectrometry system An object of the present invention is to provide a method for collecting body expiration gas and a device therefor.

[0006]

As a result of intensive studies, the present inventor was able to solve the above-mentioned conventional problems.
That is, the present invention, breath gas from a subject to which a stable isotope is administered, is directly collected through a mouthpiece into a flexible bag that can be sealed in a closed system, and after a set amount of breath is collected in the flexible bag, The exhaled gas from the subject is further collected in a closed system-closable exhaled gas collection bag, and after a set amount of exhaled gas is collected in the exhaled gas collection bag, the exhaled gas in the exhaled gas collection bag is exhaled. The present invention provides a method for collecting stable isotope exhaled gas, which is collected in a gas collection container.

[0007] The present invention also provides a mouthpiece mounting port for mounting a mouthpiece, a flexible bag connected to the mouthpiece mounting port and placed in a closed box, and adjusting the air pressure in the closed box. A breathing gas collection bag that is provided via a pressure valve and branches from a connection line between the mouthpiece attachment port and the flexible bag, and is placed in a closed box; and the air pressure in the closed box. To provide a stable isotope exhaled gas collecting apparatus comprising: means for adjusting the air flow; and a collected gas discharge valve capable of exhausting the exhaled gas in the exhaled gas collecting bag.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for collecting stable isotope breath gas and an apparatus therefor according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an example of a stable isotope expiratory gas sampling device according to the present invention.

In FIG. 1, what is indicated by reference numeral 1 is
Mouthpiece attachment port, 2 is a flexible bag, 3 and 7 are closed boxes, 4 and 8 are pistons, 5 and 9 are pressure valves, 6 is an exhalation gas collection bag, 10 is a check valve, and 11 is a collection gas discharge valve. , 12 is a collection gas discharge needle, 13 is a breath gas collection container,
14 is a discharge valve.

As shown in FIG. 1, the mouthpiece mounting opening 1 is connected to a flexible bag 2 enclosed in a closed box 3. Flexible bag 2
On the other side, a discharge valve 14 is provided, and is opened when the gas stored in the flexible bag 2 is discharged. Flexible bag 2 is closed box 3
Since the air pressure in the closed box 3 can be changed by the piston 4 attached to the flexible bag 2, the capacity of the flexible bag 2 can be changed.

A pressure valve 5 is provided on one of the pipes branched from the mouthpiece mounting port 1. The pressure valve 5 can be opened when the flexible bag 2 is filled with the set volume of exhaled gas and the pressure increases to reach the set pressure.

A pressure valve 9 is provided in the other pipe branched from the mouthpiece mounting port 1.
The pressure valve 9 can be opened when the flexible bag 2 and the exhaled gas collection bag 6 are filled with the set volume of exhaled gas and the pressure rises to the set pressure.

A check valve 10 is provided downstream of the pressure valve 5 to allow the exhaled gas to flow only in a certain direction. Further, at the subsequent stage of the check valve 10, an expired gas collection bag 6 enclosed in a closed box 7 is connected. Since the expiration gas collection bag 6 can change the air pressure in the closed box 7 by the piston 8 attached to the closed box 7, the capacity of the expiration gas collection bag 6 can be changed. Has become.

A collection gas discharge valve 11 and a collection gas discharge needle 12 are provided at a stage subsequent to the expiration gas collection bag 6. The sampling gas discharge valve 11 is opened when desired.
Can be closed. Further, the collected gas discharge needle 12 can puncture a sealed mouth of the expired gas collection container 13 to discharge the expired gas filled in the expired gas collection bag 6 to the expired gas collection container 13.

Next, a method of collecting stable isotope breath gas will be described. After the administration of the stable isotope ¹³ C, the subject holds the mouthpiece attached to the mouthpiece attachment opening and ventilates once as follows. When the volume of the flexible bag 2 determined by the air pressure in the closed box 3 by the piston 4 is filled with exhalation, the pressure valve 5 is opened. Exhaled air passes through check valve 10,
The capacity of the expiration gas collection bag 6 determined by the air pressure in the closed box 7 is filled by the piston 8. When the set volume of the flexible bag 2 and the exhaled gas collection bag 6 is filled with exhaled gas and the pressure rises, the pressure valve 9 is opened, and excess gas of exhaled gas is exhausted to the atmosphere. When the single ventilation is completed, all valves 5, 9, 11 are closed. The expiration gas collection bag 6 is filled with the expiration gas of only the third phase shown in FIG. Next, the sampling gas discharge valve 1
1 is opened, and the expiration gas filled in the expiration gas collection bag 6 is discharged to the expiration gas collection container 13 through the collection gas discharge needle 12 pierced in the sealed mouth of the expiration gas collection container 13.

The pistons 4 and 8 used for setting the air pressure in the closed boxes 3 and 7 may be electric pumps. The pressure valves 5 and 9, the sampling gas discharge valve 11 and the discharge valve 14 may be electromagnetic valves, and the pressure valves 5 and 9 are opened and closed by an electric signal of a pressure sensor provided in the flexible bag 2 or the expiration gas collection bag 6. It may be. Furthermore, sampling gas discharge valve 1
1 may be opened and closed by an electric signal punctured by the collected gas discharge needle 12.

The exhaled gas collected in the exhaled gas collection container 13 is subjected to isotope ratio inspection and measurement by, for example, a hospital or an inspection organization having a mass spectrometry system.

In FIG. 2, the first phase is a phase in which the last air inhaled before exhalation is inhaled only in the oral cavity or trachea, and is exhausted again by exhalation without contributing to gas exchange in the lungs. No change was observed in carbon dioxide gas, and the concentration remained at the same level as air. The second phase is a mixed phase of a gas that has contributed to gas exchange in the lungs and a gas that has not contributed to gas exchange in the oral cavity and trachea. The third phase is a phase in which gas that has contributed to gas exchange in the lungs is exhaled.

[0019]

According to the present invention, the expired gas collection bag 6
Since only the third phase of alveolar air is collected, an accurate isotope ratio can be measured. Further, even in a hospital or a laboratory that does not have a mass spectrometry system, since only the third phase alveolar air is collected in the expired gas collection container 13, it can be brought to an institution having the system.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a stable isotope exhalation gas sampling apparatus according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing an aspect of a carbon dioxide gas concentration change obtained by measurement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mouthpiece attachment opening 2 Flexible bag 3,7 Sealing box 4,8 Piston 5,9 Pressure valve 6 Expiration gas collection bag 10 Check valve 11 Collection gas discharge valve 12 Collection gas discharge needle 13 Expiration gas collection container 14 Discharge valve

Claims (5)

[Claims] 1. An exhaled gas from a subject to which a stable isotope has been administered is directly collected through a mouthpiece into a flexible bag that can be sealed in a closed system, and after a set amount of exhaled gas is collected in the flexible bag, The exhaled gas from the subject is further collected in a closed system-closable exhaled gas collection bag, and after a set amount of exhaled gas is collected in the exhaled gas collection bag, the exhaled gas in the exhaled gas collection bag is exhaled. A method for collecting stable isotope exhaled gas, wherein the gas is collected in a gas collection container. 2. A mouthpiece mounting port 1 for mounting a mouthpiece, and said mouthpiece mounting port 1
, A flexible bag 2 placed in a closed box 3, means 4 for adjusting the air pressure in the closed box 3, and a connection line between the mouthpiece mounting opening 1 and the flexible bag 2 A breathing gas collection bag 6 that is provided through a pressure valve 5 and is placed in a closed box 7, a unit 8 that can adjust the atmospheric pressure in the closed box 7, A stable isotope exhaled gas collecting device, comprising: a sampled gas discharge valve 11 capable of exhausting the exhaled gas in the gas. 3. The stable isotope breath gas collection according to claim 2, wherein a check valve is provided between the pressure valve and the breath gas collection bag to allow the flow of the breath gas only in a certain direction. apparatus. 4. The stable isotope exhaled breath gas sampling apparatus according to claim 2, further comprising a discharge valve configured to exhaust the exhaled breath in the flexible bag. 5. A collection gas discharge needle 12 is provided at a stage subsequent to the collection gas discharge valve 11, and is provided in the expiration gas collection container 1.
5. The puncture device according to claim 2, wherein the puncture portion is punctured at the entrance portion of the third device.
Item 10. The stable isotope breath gas sampling device according to item 8.