JP3438085B2 - Carbon dioxide concentration measurement device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon dioxide concentration measuring device for measuring the concentration of carbon dioxide contained in exhaled gas.

[0002]

2. Description of the Related Art Conventionally, when optically measuring the concentration of carbon dioxide in exhaled gas, a photodetector, for example, PbSe, has conventionally been used as an infrared detector, and the absorption of light by carbon dioxide during exhalation has been used. The voltage was detected and measured.

A schematic structure of an example of such a conventional carbon dioxide concentration measuring apparatus is shown in FIGS. 9 and 10. In FIG. 9 and FIG. 10, one end 1a of the airway adapter 1 which is formed in a substantially cylindrical shape and through which breathing gas passes is a connecting end that the subject holds in his mouth, and the other end 1b is an open end communicating with the atmosphere. Has become. The middle portion of the airway adapter 1 has a rectangular cross section, and concentric circular windows 1c and 1d are formed on two opposing surfaces of the middle portion. The intermediate portion of the airway adapter 1 is detachably attached to the detection portion 2.

The detector 2 is formed in a substantially rectangular tube shape.
A U-shaped notch 2a is formed in the middle part so that the middle part of the airway adapter 1 is fitted and mounted. The two facing surfaces of the cutout portion 2a are respectively the airway adapter 1
Are in contact with the windows 1c and 1d. Notch 2 in the detector 2
A light source 3 that emits infrared light is arranged on one side of a, and an optical interrupter 5 that is rotationally driven by a motor 4 is arranged on the other side. The light interrupter 5 is concentrically formed with a plurality of light transmission holes for continuously interrupting the light emitted from the light source 3.

On the opposite side of the light source 3 with respect to the optical interrupter 5,
A filter 6 that absorbs only light having a wavelength absorbed by carbon dioxide and a photodetector 7 that is an infrared detector are arranged. The photodetector 7 is connected to the monitor body 9 via a lead wire 8. The middle part of the airway adapter 1 is a pair of ball plungers 1 provided in the detection part 2.
It is attachable to and detachable from the detection unit 2 via 0.

In the conventional carbon dioxide concentration measuring device having the above structure, the light emitted from the light source 3 is emitted from the window 1
Light emitted from the window 1d through the breathing gas in the c and the airway adapter 1 is incident on the photodetector 7 through the filter 6 as light interrupted by the photointerrupter 5. Then, the light amount corresponding to the carbon dioxide concentration is detected by the photodetector 7, and the output signal of the photodetector 7 is input to the monitor main body 9 and displayed as the carbon dioxide concentration.

[0007]

However, the above-mentioned conventional carbon dioxide concentration measuring device uses expensive PbSe as an infrared detector, and PbSe has a fast response speed but a large drift with respect to temperature change. , It is necessary to detect light continuously and intermittently. For this reason, the optical interrupter 5 and the motor 4 for rotating the optical interrupter 5 are required, which causes a problem that the device is large and heavy, and the cost is high. Further, in order to drive the motor 4 as described above, a considerable amount of electric power must be supplied, and the monitor main body 9
The power supply section of had to be enlarged. In addition, it is impossible to downsize the monitor body 9 because a circuit for demodulating the intermittent detection signal in the monitor body 9 is required. Therefore, in consideration of usability, the detection unit 2 to which the airway adapter 1 is attached has to be used at a place apart from the monitor body 9 via the lead wire 8.

On the other hand, when measuring the carbon dioxide concentration, it is desirable to feed air while looking at the display portion of the monitor body 9, and if possible, the monitor body 9 should be integrated with the detection portion 2. However, as described above, the detection unit 2 is large and heavy, and the monitor main body is also large and heavy. Therefore, if the monitor main body 9 is integrally attached to the detection unit 2, there is a problem that operability deteriorates. Further, during artificial respiration, etc., the detection unit 2 in which the airway adapter 1 is mounted between the mask put on the subject's mouth and the airbag attached to the other end.
When wearing and using, the assistant cannot observe the condition such as the complexion of the subject and the carbon dioxide concentration display part at the same time because the detection part 2 and the monitor main body 9 are apart, so the eyes must be constantly moved. There was trouble such as not becoming. Further, since the detection unit 2 and the monitor body 9 are separated from each other, the monitor body may fall when the patient is transported by a stretcher, or the lead wire 8 connecting the detection unit 2 and the monitor body may be broken in some cases. There was also the fear of.

The present invention has been made in view of the above circumstances, and the size of the detection unit is reduced, and the flow path of the airway adapter is arranged so as to be disposed in a direction intersecting the display surface of the monitor body. An object of the present invention is to provide a carbon dioxide gas concentration measuring device capable of safely and reliably measuring the carbon dioxide gas concentration while observing the state of the subject by integrally mounting the monitor unit on the monitor body.

[0010]

In order to achieve the above object, the present invention according to claim 1 provides an airway adapter through which respiratory gas passes, and holding the airway adapter,
A light source that irradiates the respiratory gas passing through the airway adapter with infrared rays, a detection section that has an infrared detector that detects the infrared rays that have passed through the respiratory gas, and a signal from the detection section In a carbon dioxide concentration measuring device comprising a monitor body for measuring the concentration of carbon dioxide in respiratory gas, the infrared detector is constituted by a heat detecting element,
A flow path of the airway adapter, which has locking means for removably locking the detection part to the monitor body, and is used when the detection part is locked to the monitor body by the locking part. It is arranged in a direction intersecting with the display surface of the monitor main body, the monitor main body and the detection unit, the length of the required when the detector is used is removed from the monitor body It is characterized by being electrically connected by a lead wire. The present invention according to claim 2 provides an airway adapter through which breathing gas passes, a light source that holds the airway adapter and irradiates the breathing gas passing through the airway adapter with infrared rays, and the breathing gas. A carbon dioxide concentration measuring device comprising: a detector having an infrared detector for detecting the transmitted infrared rays; and a monitor main body for inputting a signal from the detector to measure the concentration of carbon dioxide in the respiratory gas. , The infrared detector is composed of a heat detecting element, and has mounting / rotating means for detachably and rotatably mounting the detection unit to the monitor body, and the detection unit is provided in front of the monitor body.
When mounted and used by the mounting / rotating means,
The flow path of the airway adapter is displayed on the monitor body.
The detection unit and the monitor main body are arranged in a direction intersecting the plane, and are electrically connected by a lead wire having a length required when the detection unit is detached from the monitor main body and used. It is characterized by being.

[0011]

[Action] Also in carbon dioxide concentration measuring device of the above either configuration, constituted infrared detector with heat sensing element. For example, a thermopile (such as S60 manufactured by Dexter Research Center, USA) which has less drift and is cheaper than PbSe which is a photodetector used conventionally is used. Since the thermopile has a low drift, the optical interrupter and the motor for driving the thermopile, which have been conventionally required, are unnecessary. As a result, not only can the detector be made smaller and lighter, but the power to be supplied to the motor is also unnecessary and the demodulation circuit etc. required for the monitor body can be eliminated. I was able to In addition, whether the detector is attached to the monitor or removed
Also, the measurement can be performed. Therefore, the concentration of carbon dioxide gas contained in the breathing gas passing through the airway adapter can be measured while looking at the display portion of the monitor body.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the carbon dioxide concentration measuring device of the present invention will be described below with reference to the drawings.

1 and 2 show the configuration of an embodiment of the first invention. 1 and 2, parts corresponding to the parts of the conventional example shown in FIGS. 9 and 10 are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. The feature of this embodiment is that the infrared detector provided in the detection unit 2 is constituted by a thermopile 11, and the flow path of the airway adapter 1 is arranged in a direction intersecting with the display unit 13 for displaying the carbon dioxide concentration of the monitor body 9. There is a point. A substantially arcuate cutout portion 9a is formed on one side of the monitor body 9, and locking portions 9b and 9c are formed at both ends of the cutout portion 9a so as to project outward. Further, an operation button 12 and a display section 13 for displaying the carbon dioxide concentration are provided on the upper surface of the monitor body 9.

On the other hand, one surface 2a of the detecting portion 2 is formed in a substantially arcuate shape which fits into the cutout portion 9a of the monitor body 9, and the other surface in the longitudinal direction is elastically deformed in a U shape. Possible tongues 2b are integrally formed. Further, a step portion 2c is formed at the end of one arcuate surface 2a in the longitudinal direction. Then, when the step portion 2c is engaged with the locking portion 9c of the monitor body 9 and the detection portion 2 is fitted and mounted in the cutout portion 9a,
The tongue piece 2b is elastically deformed so that the tip 2d rides over the locking portion 9b and is locked. When locked in this way, the flow path of the airway adapter 1 is arranged in a direction intersecting the display unit 13. When the detector 2 is detached from the monitor body 9, the tongue piece 2b is pushed to release the engagement of the tip 2d with the engagement portion 9b, so that the detector 2 can be easily removed.

3 and 4 show a state in which the carbon dioxide concentration in the breath of the subject 21 is measured. In the case shown in FIG. 3, the detection unit 2 is attached to the monitor body 9, and the air bag 23 for air supply is attached to the one end 1b of the airway adapter 1 via the connection pipe 22. The other end 1 of the airway adapter 1
The mask 24 is attached to a, and the mask 24 is attached to the face of the subject 21. Then, the air bag 23 is compressed to deliver the air to the lungs of the subject 21. Airbag 2
When the hand is released from 3, the airbag 23 is restored. Examinee 2
The air sent to the first lung undergoes gas exchange in the lung and is exhausted via the airway adapter 1. The detector 2 measures the concentration of carbon dioxide in the exhaled breath.

In the case shown in FIG. 4, the mask 24 is excluded, and the other end 1a of the airway adapter 1 is connected to one end of a tracheal tube inserted into the trachea of the subject for measurement.
In this case, the detector 2 may be removed from the monitor body 9 as shown in FIG.

According to the present embodiment, the thermopile 11 is used as the infrared detector, the optical interrupter and the motor for driving the same are unnecessary, and the detector 2 is made compact and lightweight, and the monitor main body 9 is attached to the detector 2. In this state, the concentration of carbon dioxide gas in the breath can be measured, and the display unit 1 of the monitor main body 9 can be measured.
You can send air while watching 3. Therefore, the carbon dioxide concentration can be measured safely and reliably while observing the state of the subject.

The shape of the fitting portion between the detecting portion 2 and the monitor body 9 and the structure of the locking portions 9b and 9c shown in the above embodiment are merely examples, and the present invention is not limited to these.

5 and 6 show the construction of an embodiment of the second invention . In this embodiment, the detection unit 2 is detachably and rotatably mounted on one surface of the monitor body 9 via a shaft 31. The shaft 31 is provided at the center of one surface of the monitor body 9, and arc-shaped guide portions 32 centering on the shaft 31 are integrally projected at both ends of this surface.

On the other hand, a guide plate 33 is integrally provided on one surface of the detector 2 facing the monitor body 9, and the guide plate 3 is provided.
The both ends of 3 are formed with arcuate portions 33a slidably fitted in the guide portions 32 on the monitor body 9 side. Also guide plate 3
At the center of 3, there is provided a hole 34 into which the shaft 31 is detachably and rotatably inserted.

According to this embodiment, the airway adapter 1
The monitor main body 9 can be set at a desired angle with respect to the flow path, and the display unit 13 can be easily observed during measurement. 5 shows the case where the flow path of the airway adapter 1 is orthogonal to the display surface of the display unit 13, and FIG. 6 shows the case where the flow paths intersect obliquely.

In the examples shown in FIGS. 7 and 8 , the detection unit 2 is built in the monitor body 9 and only the airway adapter 1 is detachable from the monitor body 9. Monitor body 9
A U-shaped notch 9d into which the airway adapter 1 is inserted is formed on one side, and locking portions 41 are integrally provided on both sides of the notch 9d. Further, an elastic member 42 having a claw that elastically engages with the locking portion 41 is provided on the outer periphery of the airway adapter 1, and when the airway adapter 1 is mounted on the monitor body 9, the claw of the elastic member 42 is engaged. By engaging the stopper 41 , it is held at a predetermined position.

The optical axis of the detector 2 as shown in FIG. 2 built in the monitor body 9 is orthogonal to the flow path of the airway adapter 1. In the example shown in FIG. 7, the flow path of the airway adapter 1 is orthogonal to the display surface of the display unit 13 of the monitor body 9, and in the example shown in FIG.

Although the thermopile is used as the heat detecting element in the above-mentioned embodiment, the same purpose and effect can be obtained with the thermistor bolometer.

[0025]

As described above, according to the carbon dioxide concentration measuring apparatus of the present invention, the infrared detector is composed of a heat detector to reduce the size and weight of the detecting unit, and the detecting unit is a monitor unit.
Whether attached to or removed from the body
Can also be used for And in any case
In addition, the operator can send air to the airway adapter while looking at the display section of the monitor body, and can safely and surely measure the carbon dioxide concentration while observing the state of the subject.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of a first invention of a carbon dioxide concentration measuring apparatus of the present invention.

FIG. 2 is a transverse cross-sectional view showing the structure of the fitting portion between the detection portion and the monitor body of FIG.

FIG. 3 is a perspective view showing an example of a state in which the detector of FIG. 1 and a monitor main body are integrated to measure the concentration of carbon dioxide gas in the breath of the subject.

FIG. 4 is a perspective view showing an example of a state in which the detector of FIG. 1 and a monitor main body are separated to measure the concentration of carbon dioxide gas in the breath of the subject.

FIG. 5 shows a second invention of the carbon dioxide concentration measuring apparatus of the present invention.
It is a perspective view showing the composition of one example .

FIG. 6 is a perspective view showing a state in which the detection unit of FIG. 5 is rotated.

FIG. 7 is a perspective view showing an example of a carbon dioxide concentration measuring device.

FIG. 8 is a perspective view showing another example of a carbon dioxide concentration measuring device.

FIG. 9 is an explanatory diagram showing a configuration of an example of a conventional carbon dioxide concentration measuring device.

10 is a side view showing the configuration of the detection unit of FIG.

[Explanation of symbols]

1 Airway Adapter 2 Detector 3 Light Source 9 Monitor Main Body 11 Thermopile (Infrared Detector)

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Michiaki Shishido 1-31 Nishiochiai, Shinjuku-ku, Tokyo Within Nihon Kohden Kogyo Co., Ltd. (72) Inventor Katsumi Nakaichi 1-31, Nishiochiai, Shinjuku-ku, Tokyo No. 4 within Nihon Kohden Kogyo Co., Ltd. (56) Reference Japanese Unexamined Patent Publication No. 5-337102 (JP, A) Actual Development 2-131410 (JP, U) Actual Development 5-71758 (JP, U) (58 ) Fields surveyed (Int. Cl. ⁷ , DB name) G01N 33/497 A61B 5/08

Claims (2)

(57) [Claims] 1. An airway adapter through which breathing gas passes, a light source that holds the airway adapter, and irradiates the breathing gas passing through the airway adapter with infrared rays.
Carbon dioxide comprising a detector having an infrared detector for detecting the infrared rays transmitted through the respiratory gas, and a monitor body for inputting a signal from the detector to measure the concentration of carbon dioxide in the respiratory gas In the concentration measuring device, the infrared detector is composed of a heat detection element, and has locking means for detachably locking the detection part to the monitor body, and the detection part is locked to the monitor body. Flow path of the airway adapter when used by being locked by a section
It is arranged in a direction intersecting with the display surface of the monitor main body, the monitor main body and the detection unit, the length of the required when the detector is used is removed from the monitor body A carbon dioxide concentration measuring device characterized by being electrically connected by a lead wire. 2. An airway adapter through which breathing gas passes, a light source that holds the airway adapter, and irradiates the breathing gas passing through the airway adapter with infrared rays.
Carbon dioxide comprising a detector having an infrared detector for detecting the infrared rays transmitted through the respiratory gas, and a monitor body for inputting a signal from the detector to measure the concentration of carbon dioxide in the respiratory gas In the concentration measuring device, the infrared detector is composed of a heat detecting element, and a mounting / rotating means for detachably and rotatably mounting the detection unit to the monitor body is provided, and the detection unit is the monitor. By the mounting / rotating means on the main body
When installed and used, the airway adapter
The flow path of the one that intersects the display surface of the monitor body
And the detection unit and the monitor body are electrically connected by a lead wire having a length required when the detection unit is detached from the monitor body and used. Carbon dioxide concentration measuring device.