JP3083354B2 - Exhaled gas monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaled gas monitoring apparatus provided with gas component measuring means for continuously measuring a predetermined component in exhaled breath emitted from a living body by utilizing light absorption. .

[0002]

2. Description of the Related Art There is known an exhaled gas monitoring apparatus provided with gas component measuring means for continuously measuring a predetermined component in exhaled air emitted from a living body by using light absorption. The gas component measuring means usually includes an infrared light source that emits constant infrared light, a transparent sample chamber through which exhaled air passes, and a photodetector that detects infrared light transmitted through the sample chamber. The gas in the exhalation is measured based on the degree of absorption of the gas in the sample chamber with respect to infrared light.

[0003]

By the way, in the expiratory gas monitoring device provided with the optical gas component measuring means as described above, the zero point adjustment work is performed after a predetermined time warm-up period has elapsed since the power was supplied to the device. Although the measurement of the gas component in the expiration can be started after the zero point adjustment work is required, in order to maintain the accuracy, for example, two minutes, five minutes, and fifteen minutes have elapsed since the power was supplied. The zero point adjustment work was required at the time point and at the time point of 30 minutes, respectively, and thereafter, the zero point adjustment work was required every 30 minutes. For this reason, when the measurement is started following the zero adjustment work after the elapse of the warm-up period, the above zero adjustment work needs to be performed frequently,
In addition, since the zero point adjustment operation is performed by introducing the atmosphere, the measurement of the gas component in the expiration is often interrupted. In particular, when monitoring the exhalation of a patient during an operation, the above-mentioned zero adjustment operation is troublesome for a medical worker, and the interruption of the measurement due to the zero adjustment operation may cause insufficient monitoring of the patient. Was. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an exhaled gas monitoring device that does not require complicated zero point adjustment work after the start of monitoring work.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to continuously measure a predetermined component in exhaled breath discharged from a living body by using light absorption. An exhaled gas monitoring device provided with gas component measuring means, comprising: (a) a monitoring operation preparation stage detecting means for detecting that a preparation stage for a monitoring operation by the exhaled gas monitoring device has been reached; and (b) the monitoring operation. A start signal for automatically supplying a start signal for bringing the gas component measuring unit into a measurement state when the preparation stage detecting unit detects that the preparation stage of the monitoring operation by the expired gas monitoring device has been reached. Supply means.

[0005]

In this way, when it is detected by the monitoring operation preparation stage detecting means that the preparation stage for the monitoring operation by the exhaled gas monitoring device has been reached, the starting signal supply means measures the gas component measuring means. A start signal for setting the state is automatically supplied.

[0006]

The monitoring operation preparation stage detecting means detects, for example, that an operator has entered the operating room or that the lighting of the operating room has been turned on. This is to detect that the preparation stage has been reached, and a considerable time elapses from the start of the preparation stage to the start of the actual operation. Therefore, at the time of the actual start of measurement by the exhaled gas monitoring device, a sufficient time has elapsed since the start signal for automatically setting the gas component measurement unit to the measurement state by the start signal supply unit. This eliminates the need for frequent zero adjustment after the measurement by the exhaled gas monitoring device is started, and eliminates the interruption of measurement due to the zero adjustment.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a main part of the front of a breath gas monitoring apparatus 10 to which the present invention is applied. In the figure, a power switch 14, a monitor start switch 16, a zero adjustment start switch 18, a pyroelectric sensor 20,
An elapsed time display 22 and a graphic display 24 are provided.

As shown in FIG. 2, the power switch 14
Is connected to the pyroelectric sensor 2 from the power supply circuit 26 in connection with the operation.
0 and a predetermined DC voltage to the relay circuit 28, and a predetermined power to each unit (not shown).
The pyroelectric sensor 20 detects a worker within a predetermined range from the expiratory gas monitoring device 10 or a worker in an operating room where the pyroelectric gas monitoring device 10 is arranged based on far-infrared rays emitted by the worker. In the example, it functions as a monitoring operation preparation stage detecting means for detecting that the monitoring operation by the expired gas monitoring device 10 has reached the preparation stage.

The relay circuit 28 allows a predetermined DC voltage from the power supply circuit 26 to be supplied to the measurement control device 30 in accordance with a signal from the pyroelectric sensor 20 or the monitor activation switch 16. The zero point adjustment start switch 18 supplies a start signal of a zero point adjustment operation to the measurement control device 30 in connection with the operation thereof, and causes the measurement control device 30 to start the zero point adjustment operation preferentially. . For example, when the exhalation gas monitoring is being performed when the start signal is supplied, the measurement control device 30 interrupts the exhalation gas monitoring operation up to that time and executes the zero point adjustment operation. Restart operation.

On the other hand, a first conduit 34 and a second conduit 36 for guiding exhalation through the trap 32 are sequentially provided in the exhalation gas monitoring device 10. The first conduit 34
A switching valve 38 is provided between the first and second pipes 36, and a transparent sample cell 40 and a suction pump 42 are sequentially provided in the second pipe 36, for example, obtained from a T piece. Expiration from a living body is allowed to pass through the sample cell 40 at a constant flow rate. The switching valve 38 switches the second line 36 to the atmosphere line 44 according to a command from the measurement control device 30 at the time of zero point adjustment, and releases the atmosphere from the atmosphere line 44 to the sample cell 4.
Introduce into 0.

The measurement control device 30 includes a CP (not shown).
A microcomputer including a U, a ROM, a RAM, and an input / output interface.
8. The suction pump 42, the infrared light source 46, and the filter switching motor 48 are respectively controlled.

For example, when a monitor start signal, which is a predetermined DC voltage, is supplied from the relay circuit 28 in accordance with a signal from the pyroelectric sensor 20 or the monitor start switch 16, the measurement control device 30 first sets a predetermined value. The warm-up operation is executed according to the procedure described above, and the first
The pipe 34 communicates with the second pipe 36 and the suction pump 4
At the same time as the exhalation is sucked by 2, the infrared light is continuously output from the infrared light source 46, and the rotary filter 50 is continuously rotated by the filter switching motor 48. Next, after about one minute has passed, the switching valve 38 controls the atmosphere pipe 44.
Is communicated with the second conduit 36 to guide the atmosphere into the sample cell 40, and the zero point adjustment of the gas concentration measurement is performed based on the intensity of the transmitted light detected by the photosensor 52 at this time. When the zero point adjustment is completed, the first line 34 and the second line 36 are again communicated by the switching valve 38, and the exhaled gas monitor is activated.

The measurement control device 30 measures the elapsed time from when the monitor start signal is supplied from the relay circuit 28 and displays it on the elapsed time display 22. This is for notifying the operator of the degree to which various characteristics such as the zero point in the exhaled gas monitoring device 10 are becoming stable. Note that the above-described zero-point adjustment operation is similarly executed when the zero-point adjustment start switch 18 is operated.

The rotary filter 50 is, for example, a CO
₂ filter comprises N ₂ O filter, the reference filter, a blank filter that shields for timing, a filter for shielding infrared light. The CO ₂ filter is for passing light in a band of infrared light that is most absorbed by CO ₂ , and the N ₂ O filter is most absorbing of N ₂ O of infrared light. This is for allowing light in a specified band to pass. The photo sensor 52 includes
Since the infrared light that has passed through each filter provided in the rotary filter 50 and the sample cell 40 is received, an optical pulse corresponding to each filter is output. The height of the light pulse corresponding to the CO ₂ filter and the N ₂ O filter decreases as the concentration of CO ₂ and N ₂ O increases.

For this reason, the measurement control device 30 sets the zero point in advance in the exhalation gas monitor operating state in which the first conduit 34 is connected to the tube for guiding exhalation from the anesthesia intubation and the exhalation gas is actually introduced into the sample cell 40. Based on the relationship, the concentrations of CO ₂ and N ₂ O contained in the breath are repeatedly determined based on the height of the light pulse, and the monitor waveforms are graphically displayed by sequentially plotting the concentrations on the time axis. 24. Further, the maximum value of the monitor waveform is displayed as a number. In this embodiment, the sample cell 40, the suction pump 42, the infrared light source 46, the filter switching motor 48, the rotary filter 50, the photo sensor 52, and the like correspond to a gas component measuring unit.

In the expired gas monitoring apparatus 10 of the present embodiment configured as described above, the worker is detected within a predetermined detection range by the pyroelectric sensor 20 corresponding to the monitoring operation preparation stage detecting means. The monitor start signal is sent from the relay circuit 28 corresponding to the start signal supply means to the measurement control device 30.
When the measurement control device 30 supplies warming up, warm-up of the suction pump 42, the infrared light source 46, the filter switching motor 48, and the like is automatically started, and
One minute later, the zero point adjustment operation is performed and then the apparatus is put on standby in the monitor operation state. The pyroelectric sensor 20 includes:
For example, by detecting that an operator has entered the operating room, it is detected that the preparation stage of the monitoring operation by the expired gas monitoring device 10 has been reached. A considerable time elapses before is started. Therefore, the expired gas monitoring device 10
At the time of the actual start of measurement, since a sufficient time has elapsed since the start signal required for the measurement is automatically supplied to the gas component measuring means by the relay circuit 28, the expiratory gas monitoring device 10 This eliminates the need for frequent zero adjustment work after the measurement is started, and eliminates the interruption of measurement due to the zero adjustment work.

Further, according to the present embodiment, the elapsed time display 22 displays the elapsed time since the start signal is automatically supplied from the relay circuit 28 to the gas component measuring means. Even when the actual expiration is introduced and the measurement is started in a state where sufficient time has not elapsed since the activation signal was supplied, even at an appropriate interval according to the elapsed time displayed on the elapsed time display 22. Zero point adjustment can be activated.

Although the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments. For example, in the above-described embodiment, the fact that the preparation stage for the monitoring operation by the exhaled gas monitoring device 10 has been reached is determined by the pyroelectric sensor 20 detecting the worker within a predetermined detection range. Alternatively, an illuminance sensor that detects that the lighting in the operating room where the exhaled gas monitoring device 10 is arranged is turned on may be used, or the light from the lighting in the operating room may be received and the operator may use the illuminance sensor. A photosensor that detects that light is blocked by a change in the amount of received light may be used.

In the above-described embodiment, the zero-point adjustment operation is started by the zero-point adjustment start switch 18. However, two minutes, five minutes, fifteen minutes, and three minutes after the start.
Timer control means may be provided so that the zero adjustment operation is automatically started after 0 minute.
Further, instead of such an automatic start of the zero adjustment operation, a display for instructing the operation of the zero adjustment start switch 18 is displayed at 2, 5, 15, and 30 minutes after the start. It may be.

The above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of an expired gas monitoring device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a main part of an electrical configuration and a mechanical configuration in the apparatus of FIG. 1;

[Description of Signs] 20 Pyroelectric sensor (monitoring operation preparation stage detecting means) 28 Relay circuit (start signal supplying means) 40 Sample cell ┐ 42 Suction pump ├ (gas component measuring means) 46 Infrared light source │ 48 Filter switching motor ┘ 50 Rotary filter ┬ (gas component measuring means) 52 Photo sensor ┘

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiro Okumura 2007 No. 1 Hayashi, Komaki City, Aichi Prefecture Within Colin Electronics Co., Ltd. (58) Field surveyed (Int. Cl. ⁷ , DB name) A61B 10/00 A61B 5 / 08 A61M 16/00 370

Claims (1)

(57) [Claims] 1. An expiratory gas monitoring device comprising gas component measuring means for continuously measuring a predetermined component in exhaled gas discharged from a living body by utilizing light absorption, said exhaled gas monitoring device comprising: Monitoring operation preparation stage detecting means for detecting that the monitoring operation preparation stage has been reached, and when the monitoring operation preparation stage detecting means detects that the expiration gas monitoring device has reached the monitoring operation preparation stage. A start-up signal supply unit that automatically supplies a start-up signal for bringing the gas component measurement unit into a measurement state.