JPS5921772Y2 - Breathing information measurement sensor - Google Patents

Description

[Detailed description of the invention] This invention relates to a respiratory information measuring sensor used to measure respiratory information of a subject, and in particular, a part of the flow sensor is
The present invention relates to a respiration information measurement sensor that incorporates a gas concentration detection sensor such as O2 and is provided with a light-transmitting window for detection light.

Generally, the measurement of CO2 concentration in exhaled breath or the measurement of ventilation volume is carried out using a device as shown in FIG.

In the figure, a subject 1 holds a connecting end 21 provided at one end of a hollow connecting tube 2 in his mouth and breathes into an open end 22.

Translucent windows 31 and 32 provided in a part of the connecting tube 2 are airtightly bonded with sapphire or the like, so if the light source 4 is energized by the power source 5 to emit light, transmitted light can be obtained as shown by the arrow. .

This transmitted light is converted into intermittent light by a chopper 7 controlled by a drive unit 6 consisting of a motor or the like.

From this intermittent light, the spectral filter 8 transmits only light having a wavelength that is absorbed by the CO□ gas.

This transmitted light is photo-electrically converted by the detector 9 and then passed through the amplifier 1.
0 amplifies this.

The detector 11 detects this, and the logarithmic amplifier 12 logarithmically amplifies it to obtain the CO2 concentration as its output.

Further, after the CO2 concentration of the exhaled gas of the subject 1 is measured in the connecting pipe 2, it is guided to the current velocity meter 41 via the bellows pipe 40, and the flow sensor 13 inside the current meter 41 generates an electric signal proportional to the flow velocity. is converted to

The electrical signal obtained by this flow sensor 13 is sent to the amplifier 1
4, rectified by diode 15, and integrator 1.
The exchange quantity can be obtained from the output of 6.

However, in the above device, the CO2 sensor and the flow sensor are arranged in series and separated from each other, which not only increases the size of the system as a respiratory information measurement sensor, but also increases the dead space inside the device, causing the risk of rebreathing of exhaled air. there were.

The present invention was devised in view of the above, and aims to provide a respiratory information measuring sensor in which a CO2 sensor can be incorporated into a part of a flow sensor.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view of the respiratory information measuring sensor of the present invention.

The connecting pipe 20 has a pinched portion 23 near the middle, and the flow path is narrow.

The narrow part 23 is formed by cutting the upper and lower parts of the connecting part 20 and
31 and 232 are provided, and transparent windows 24 and 25 made of sapphire or the like are adhered to these steps to form an airtight structure.

Figure 3 is a sectional view taken along the line A-A' in Figure 2, showing the transparent window 24.25.
is formed so that light irradiated from the outside enters through one light-transmitting window 25 and is emitted from the other light-transmitting window 24.

Therefore, in this state, the breathing gas passing through the flow path of the connecting tube 20 absorbs a specific wavelength corresponding to the gas to be measured out of the light incident through the transparent window 25 due to the gas concentration.

Further, differential pressure outlets 26 and 27 are provided before and after the flow path centered on the narrow portion 23.

Therefore, if a differential pressure gauge (not shown) or the like is connected to the tips of these differential pressure outlets 26 and 27, the exhalation flow rate can be determined from these.

Next, the respiration information measuring sensor of this invention is connected to the connecting pipe 2 in Fig. 1.
The measurement of CO2 concentration and ventilation amount when used in place of the flow sensor 13 will be described.

The exhaled breath of the subject 1 passes through the flow path in the connecting tube 20 and is discharged to the outside from the open end.

The light emitted by the light source 4 enters through the transparent window 25, passes through the exhaled gas passing through the narrow part 23, and is guided from the transparent window 24 to the spectral filter 8.

The chopper 7 converts this light into intermittent light, and the spectral filter 8 passes from this intermittent light only light of wavelengths that are absorbed by exhaled gas.

This light is photo-electrically converted by the detector 9.

Note that measuring the CO2 concentration from this signal is the same as described above.

Also, at this time, a pair of differential pressure outlet ports 2 are provided before and after the pinched portion 23.
6.27 is provided open to the flow path and generates a pressure difference depending on the exhalation flow rate.

Therefore, by connecting the tips of the differential pressure outlets 26 and 27 to a differential pressure gauge, amplifying the output, and linearizing it with an appropriate linearizer, an electrical signal proportional to the flow velocity can be obtained.
By integrating this, the ventilation amount can be determined.

In this way, the present invention provides a transparent window made of sapphire or the like in a part of the flow sensor to allow light to pass through.
It is now possible to incorporate a CO2 sensor, and the C
It exhibits an excellent effect in that the O2 concentration can be measured extremely accurately without any time delay.

Further, there is an advantage that the respiratory information measuring sensor can be miniaturized and the dead space where exhaled air may be re-breathed is reduced.

[Brief explanation of drawings]

Figure 1 is a general explanatory diagram of ventilation volume and CO2 concentration measuring device,
FIG. 2 is a perspective view of the respiratory information measuring sensor of the present invention, and FIG. 3 is a sectional view taken along the line AA' in FIG. 20... Respiratory information measurement sensor, 23...
・Small part, 24゜25...transparent window, 26.27
・・・・・・Differential pressure outlet.

Claims (1)

[Scope of utility model registration request] A part of the flow path made up of a tubular member is used as a narrow part, and differential pressure outlets are provided before and after the narrow part to take out the pressure in the flow path, and detection light is transmitted through the gas flowing inside the flow path. A respiratory information measuring sensor characterized in that a translucent window that can be transmitted through is airtightly provided to the narrow part.