JPH09276408A - Gas for respiration supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically adjust the degree of humidification even when the flow rate of oxygen gas is changed by directly bypassing non-humidified oxygen gas to the passage of a piping means and automatically performing control for opening and closing the solenoid valve of a humidification degree adjustment means based on the output signals of a humidity sensor. SOLUTION: The humidification degree adjustment means 32 bypasses the oxygen gas kept dried without being passed through a humidification means 14, mixes it with the humiditied oxygen gas passed through the humidification means 14 and provides gas for respiration having appropriate humidity to be supplied for the respiration. Then, the solenoid valve is operated correspondingly to the output signals of the humidity sensor 24 and the passage of the oxygen gas is communicated and closed by the block of an orifice correspondingly to the opening and closing operation of the respective solenoid valves. The humidification degree adjustment means 32 constituted in such a manner is used, and in the case of adjusting the humidification degree by the flow rate of the oxygen gas, the humidification degree changed by the flow rate of the oxygen gas is automatically adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breathing gas supply apparatus using a gas humidifier having a specific structure. More specifically, there is provided a breathing gas supply device capable of moderately humidifying the gas even when the flow rate of the gas changes greatly and automatically adjusting the humidification to a value within a predetermined range. It is provided.

[0002]

2. Description of the Related Art Oxygen therapy in which oxygen gas (including oxygen-enriched gas, the same applies hereinafter) is inhaled by a patient with respiratory disease (hereinafter simply referred to as “patient”) is carried out using oxygen gas. There is a cylinder, a device that vaporizes and uses liquid oxygen, etc., but recently, oxygen gas obtained by concentrating oxygen in the air by a pressure fluctuation adsorption method (hereinafter referred to as PSA method) has come to be used. Came.

Since these oxygen gases are in a very dry state containing almost no water, it is usually necessary to humidify and inhale by a humidifier in order to prevent the patient's nasal cavity from drying out when inhaling. There is. In general, this humidifier is one in which water is put in a container, oxygen gas is introduced into the water, and air bubbles are passed through the water to humidify. The sound of the bubbles bursting on the surface of the water becomes noise, and this noise often annoys patients and their families especially at night when the surroundings are quiet.

In order to suppress this noise, measures may be taken such as providing a box or the like for sound insulation. Also,
In this conventional humidifier, the oxygen gas to be humidified is humidified to a relative humidity of about 95 to 100%, so that the tube for supplying it to the nasal cavity of the patient passes through the space of low temperature. When it is discharged, the oxygen gas is cooled, so that dew condensation is likely to occur and water droplets are likely to be generated. Water droplets could get into the patient's nose.

The conventional water container of the humidifier is
Bacteria, mold, algae, etc. easily propagate, and these move with the splash of water due to the rupture of bubbles and enter the respiratory system of the patient, which may cause infections and prevent them. It was necessary to clean the container at least once a week for cleaning. For this reason, there is a work of removing and installing the container, and the burden of this work is heavy for a patient who is relatively weak, and oxygen gas leaks because the lid of the container is not fully covered. There was also an accident.

[0006]

SUMMARY OF THE INVENTION The present invention is intended to solve such problems. That is, various bacteria, molds, algae, etc. are not mixed in the oxygen gas for inhalation, and no noise is generated due to the burst of air bubbles,
Moreover, it is possible to provide a breathing gas supply device by the PSA method that can automatically adjust the degree of humidification to a value within a predetermined range even if the flow rate of oxygen gas used changes within the predetermined range. It is intended for.

[0007]

In order to achieve such an object, it has been found that it is effective to use a perfluoro-based ion exchange membrane material or the like, and to use a moisture permeable membrane that allows only moisture to permeate. The present invention has been reached. This water-permeable membrane is processed into a tubular hollow fiber, the hollow fiber is passed through a container 18 containing water, and oxygen gas in which atmospheric oxygen is concentrated by the PSA method is passed through a passage in the hollow fiber. By using the humidifying means configured to cause no noise due to the bursting of bubbles, the humidity of the oxygen gas after passing through the humidifying means is detected, and the bypass passage is controlled by the value. , The flow rate of the oxygen gas is
Even if it changes within a certain range, the degree of humidification is about 7
It is configured so as to be automatically controlled so as to be 0 to 80%.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention is as follows. At least one adsorption cylinder filled with an adsorbent that selectively adsorbs nitrogen gas as a strongly adsorptive gas, pump means 10 for supplying compressed air to the adsorption cylinder, automatic valve means 12,
In the respiratory gas supply device by the PSA method basically constituted by the humidifying means 14 having a function of humidifying the generated oxygen gas for breathing, the humidifying means can substantially permeate only water. Hollow fiber processed water permeable membrane 1
6 through the container 18 containing water, and through the passage in the hollow fiber from the inlet end 20 of the container toward the outlet end 22 of the container, passing the oxygen gas for breathing, It is configured to humidify the oxygen gas, and the outlet end 22 and the humidification / inhalation oxygen outlet 30 are connected by piping means, and a humidity sensor 24 is attached in the middle of the piping means. At the same time, a humidification adjusting means 32 is attached via a piping means between the inlet end 20 of the container and a bypass connection point 29 provided in the piping means so that unhumidified oxygen gas is supplied to the humidification means. The humidity adjusting means 3 is configured so as to bypass the piping means directly without going through 14.
This is a breathing gas supply device configured to automatically control the opening and closing of the second solenoid valves 54, 56, 58 based on the outlet signal of the humidity sensor 24.

Even if the amount of water contained in a unit volume of gas is constant, the relative humidity changes when the atmospheric temperature changes. Therefore, the humidity sensor 24 uses the relative humidity in consideration of the atmospheric temperature. The above-mentioned breathing gas supply device is characterized in that a relative humidity sensor capable of measuring is used. Further, the present invention is a breathing gas supply apparatus, characterized in that the adsorption cylinder configured as described above is filled with a small amount of a hygroscopic agent together with an adsorbent. Further, according to the present invention, the flow rate measuring means 3 is provided between the inlet end 20 of the container configured as described above and the flow rate adjusting means 34.
6 is attached through a piping means, and the flow rate value of the gas flowing in the flow rate measuring means is displayed on the flow rate display unit 38 based on the output signal of the flow rate measuring means. The respiratory gas supply device according to any one of items 1 to 3.

As described above, the conduits connected to the inlet end 20 of the hollow fiber for introducing the dry oxygen gas to be humidified and the hollow fiber outlet 22 for the outlet of the humidified oxygen gas. A humidification adjusting means 32 is provided as an bypass means in the extension part of the means, and the humidified oxygen gas and the non-humidified dry oxygen gas are supplied on the basis of the output signal of the humidity sensor 24. Even when the flow rate of the oxygen gas discharged from the humidification inhalation oxygen outlet 30 is changed by the flow rate adjusting means 34, the humidity of the oxygen gas is automatically adjusted by automatically mixing and mixing. It is configured to have a value within a substantially desired range.

Since the water in the container 18 is consumed as it is used for humidification, the replenishing port 40 serves as a water replenishing means.
Is attached so that water can be replenished as needed.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a flow chart of a breathing gas supply apparatus according to a preferred embodiment of the present invention. In addition, illustration of the power supply line is omitted in this figure. In the figure, the suction filter 42 sucks the ambient air by the pump means 10, and when suctioning / compressing the air and supplying it to the automatic valve means 12 of the breathing gas supply apparatus by the PSA method, the dust in the atmosphere is removed. And dust.

The structure from the automatic valve means 12 to the throttle valves 46, 47 via the adsorption cylinders 44, 45 is a well-known structure as a breathing gas supply device by the PSA method, and detailed description thereof will be omitted. Then, here, the constitution of the humidifying means 14, the makeup water container 48, etc., which are provided with the hollow fiber permeable membrane, which is a constitution peculiar to the present invention, and the operation and effect thereof will be explained.

In the figure, the hollow fiber 16 is shown as a single tube, but the actual construction is 0.3 mm in outer diameter and 0.15 mm in inner diameter made of perfluoro ion exchange membrane.
A bundle of about 3,500 hollow fibers having a length of about 25 cm was used. Further, the material of the hollow fiber 16 is not limited to the perfluoro ion exchange membrane, and may be a polysulfone porous membrane or the like.

The hollow fiber 16 is a moisture permeable membrane that substantially allows only moisture to permeate therethrough. The moisture permeable membrane is processed into a hollow fiber shape, and the hollow fiber is passed through a container containing water. When a dry oxygen gas for humidification is passed through the passage in the chamber, only the moisture will pass through the partition wall of the hollow fiber to give the oxygen gas with moisture. For example, about 70-80%).

Here, if the dry oxygen gas is passed through the hollow fibers 16 of the humidifying means 14 (indicated by the dashed line) to humidify the water, the water in the container 18 will be consumed and the amount will be reduced. However, in the present embodiment, the replenishment method is configured as follows. A make-up water container 48 is provided separately from the humidifying means 14, and the make-up water container 48 and the make-up port 40 attached to the container 18 of the humidifying means 14 are connected by a water supply pipe 49 so that water in the make-up water container is connected. Is configured to be able to replenish only the amount consumed in the container.

The humidifying means 14 is substantially airtight, and the inside of the container 18 is initially filled with distilled water in an amount of about 3/4 of the volume excluding the hollow fiber 16 in the container. The container has an outer diameter of about 38 mm and an inner diameter of about 35 mm.
It was made of a transparent plastic material having a length of 28 mm and a length of 28 mm.

The humidifying means 14 thus constructed has the following operational effects. When the dry oxygen gas is passed through the inner passage of the hollow fiber 16 through which substantially only water is permeated, the water contained in the outer side of the hollow fiber humidifies the oxygen gas through the membrane of the hollow fiber. And container 18
Is watertight, the same amount of water as water consumed for humidification is supplied from the makeup water container 48. Since the lid of the makeup water container 48 has an air hole having a diameter of about 1 mm, the makeup water can be supplied in a necessary amount. Even if the lid is not tightened sufficiently, no trouble such as gas leakage will occur.

In FIG. 1, the flow rate adjusting means 34 is
The flow rate when the oxygen gas generated by the breathing gas supply apparatus by the PSA method is discharged from the humidified inhalation oxygen outlet 30 to be used for breathing [flow rate per minute / liter / liter /
(L / min)], and an orifice or a throttle valve or the like is attached in the middle of the piping means that is the oxygen gas passage. In the first embodiment of the present invention, a plurality of orifices having different diameters are appropriately switched so that the flow rate can be selected, and a numerical value corresponding to each flow rate value can be displayed in conjunction with the flow rate adjusting means. did. (For example,
"0.5 L / min", "1.0 L / min", "1.5 L / min"
Minutes ")

The humidifying means 32 bypasses the oxygen gas which has not dried yet passes through the humidifying means 14, and mixes with the oxygen gas humidified through the humidifying means 14 to provide an appropriate amount for breathing. It is intended to obtain a breathing gas having humidity.

FIG. 2 is a flow chart showing the detailed construction of the humidification adjusting means 32. The power supply line is not shown in this figure as well. The humidifying means 32 is roughly composed of the following two blocks. The output signal of the humidity sensor 24 is amplified and three comparators each having a different threshold value (humidity 74.5
%, 83%, 93% equivalent value) and outputs an output signal corresponding to each humidity.

The solenoid valves 54 to 58 that operate in response to the output signals described above and the orifices 60 to 64 for opening and closing the passages of oxygen gas in response to the opening and closing operations of the respective solenoid valves. block. This orifice has a pressure on the primary side of 3 kPa {0.03 kgf /
cm ² · G}, the flow rate of oxygen gas is 0.12 L / min (2
If the temperature is 0 ° C., a diameter of 0.2 mm is suitable. It should be noted that although a display means of a light emitting diode for indicating that the solenoid valve or the like is in an operating (open) state is provided corresponding to these solenoid valves (orifices), these are not shown.

FIG. 3 is a graph diagram comparing the humidification with respect to the oxygen gas flow rate when the humidification control means 32 having the above-mentioned configuration is used to adjust the humidification depending on the flow rate of oxygen gas, and when not. is there. In the same figure, the curve A shows the relationship between the flow rate of oxygen gas and the humidity when the humidity control is not performed at the oxygen inlet 30 for humidification inhalation. It goes without saying that this is the same as the value measured by the humidity sensor 24. In this way, the flow rate is 0.5L
95% at / min, 89% at 1.5L / min, 2.5L / min
It becomes 78% in minutes and 71.5% in 3.5 L / min.

On the other hand, the curve B is for the case where the humidity sensor 24 and the humidity adjusting means 32 are used to automatically adjust the humidity changing depending on the flow rate of oxygen gas, and the flow rate is 0.5 L / Min, 78%, 1.5 L / min, 76.5%, 2.5 L / min, 74%, 3.5 L / min, 71.5%. Since the humidity adjustment is not performed at 3 L / min or more, both curves are the same.

The orifice 60 of the humidifying means,
In this embodiment, 62 and 64 have the same diameter (0.2 mm).
However, the present invention is not limited to this example, and even if the orifices having different diameters are individually and sequentially switched and adjusted, the effect of the present invention does not change. (For example, 0.2mmφ, 0.28m
mφ, 0.35mmφ)

Although various types of humidity sensors are commercially available, a so-called electronic type which can output a change in humidity as an electric signal is preferable as a constituent element of the present invention. In this embodiment, the electronic humidity sensor 24 using the polymer film is used, but the humidity sensor is not limited to this example, and a ceramic or semiconductor humidity sensor may be used. Oxygen gas discharged from the humidifying / inhaling oxygen outlet 30 is condensed in a tube such as a cannula only when the relative humidity of the oxygen gas reaches 100%, and the moisture content per unit volume of the gas is reduced. Even if the amount is constant, if the ambient temperature changes, the relative humidity also changes.
For No. 4, it is more preferable to use a relative humidity sensor capable of measuring the relative humidity in consideration of the ambient temperature. (For example, a gas whose relative humidity is 75% at 20 ° C is 1
(When the temperature drops to 7 ℃, the relative humidity becomes 100% and dew condensation occurs.)

In the present embodiment, the position where the humidity sensor 24 is attached is between the outlet end 22 of the humidified oxygen gas and the bypass connection point 29, but the position where the humidity sensor is attached is not limited to this example. May be provided between the bypass connection point 29 and the humidification inhalation oxygen outlet 30 and the effect of the present invention is not changed. However, in the latter case, since the humidity after mixing with the bypass airflow is measured, it is necessary to consider that the threshold value of the comparator has a sufficient hysteresis width in order to prevent so-called hunting. Also, in a breathing gas supply device that uses a conventional bubble-type gas humidifier, if oxygen gas passes through this gas humidifier, bubbles will be generated, so you can visually confirm the generation of oxygen gas. Although it was possible, in the gas humidifier of the present invention, since no bubbles are generated, it is quiet, but on the other hand, it is not possible to visually check the generation state of oxygen gas.

(Embodiment 2) FIG. 4 is a flow chart of a second embodiment of the present invention, in which the structure on the downstream side beyond the flow rate measuring means 36 and the structure of the part of the breathing gas supply device by the PSA method are shown. The description of is omitted. (It is the same as that disclosed in the first embodiment, and the illustration of the power supply line is also omitted.) In the figure, the flow rate adjusting means 34 is the PS as described above.
This is to adjust the flow rate (L / min) when the oxygen gas generated by the breathing gas supply device according to the method A is discharged from the humidified inhalation oxygen outlet 30 to be used for breathing.

In the second embodiment, the flow rate measuring means 36 is provided downstream of the flow rate adjusting means 34 via conduit means.
Is connected, the flow rate of the oxygen gas flowing in the flow rate measuring means is measured, and the flow rate signal is transmitted to the display control means 50. The humidifying means and the like downstream of the flow rate measuring means and the configuration of the breathing gas supply device by the PSA method are the same as in the first embodiment. The display control means 50 displays the flow rate on the basis of the flow rate signal by the flow rate display section 38.
It is for producing an electric signal to be displayed by (for example, an LED or a liquid crystal display). Although the mass flow type flow rate sensor is used in the present embodiment as the flow rate measuring means 36, the flow rate measuring means 36 is not limited to this example and may be any sensor as long as it can convert a flow rate value into an electric signal by an ultrasonic method or the like. May be.

In the first embodiment, the flow rate adjusting means 34 is
Although a plurality of orifices having different diameters were switched stepwise, the flow rate of the oxygen gas can be displayed moment by moment in the second embodiment, so the flow rate adjusting means 34 is a needle valve type variable valve capable of continuously adjusting the flow rate. Although the throttle valve is used, needless to say, an orifice type may be used. Then, it is possible to visually confirm that oxygen gas is generated. Further, based on this flow rate signal, an alarm can be issued when the flow rate falls outside a certain range.

[0031]

By implementing the present invention, the following excellent operational effects can be expected. When humidifying the oxygen gas obtained by the breathing gas supply device by the PSA method, there is no sound of bubbles bursting on the water surface unlike the conventional bubble type humidifier, which is a good news for patients and their families. Even if the flow rate of oxygen gas changes within a predetermined range, the humidity can be automatically adjusted to a range of about 70 to 80%.

[Brief description of drawings]

FIG. 1 is a flow chart of a breathing gas supply apparatus according to a preferred embodiment of the present invention.

FIG. 2 is a flowchart showing a detailed configuration of a humidity adjusting means.

FIG. 3 shows the case of using the humidifying means of the present invention,
It is a graph which compared the humidification with respect to the flow volume of oxygen gas in other cases.

FIG. 4 is a flow chart of a breathing gas supply apparatus according to another embodiment.

[Explanation of symbols]

 10 Pump Means 12 Automatic Valve Means 14 Humidification Means 16 Hollow Fiber 18 Container 20 Inlet End 22 Outlet End 24 Humidity Sensor 26 Gas Inlet End 28 Gas Outlet End 29 Bypass Connection Point 30 Humidification Suction Oxygen Outlet 32 Humidification Adjusting Means 34 Flow Rate Adjusting means 36 Flow rate measuring means 38 Flow rate display section 40 Supply port 42 Inhalation filter 44,45 Adsorption cylinder 46,47 Throttle valve 48 Makeup water container 49 Water supply pipe 50 Display control means 52 Block 54, 56, 58 solenoid valve for outputting output signal 60, 62, 64 Orifice 72 Buffer tank 74 Pressure reducing valve 76 Silencer 78 Oxygen gas inlet 80 Oxygen gas outlet 82 Humidity sensor signal input

Claims (4)

[Claims] 1. An at least one adsorption column filled with an adsorbent that selectively adsorbs nitrogen gas as a strongly adsorbing gas,
Pump means (10) for supplying compressed air to the adsorption cylinder,
Respiratory gas by a pressure fluctuation adsorption method basically constituted by automatic valve means (12) and humidifying means (14) having a function of humidifying generated oxygen gas for breathing (including oxygen-enriched gas, the same applies hereinafter) In the supply device, the humidifying means passes a hollow fiber (16) processed with a moisture permeable membrane capable of substantially permeable only moisture through a container (18) containing water,
The oxygen gas, which is used for breathing, is passed through the passage in the hollow fiber from the inlet end (20) of the container toward the outlet end (22) to humidify the oxygen gas. In addition, the outlet end (22) and the humidification inhalation oxygen outlet (30) are connected by piping means, and a humidity sensor (24) is attached in the middle of the piping means. Humidity adjusting means (3) is provided between the inlet end (20) of the container and the bypass connection point (29) provided in the piping means.
2) is attached via piping means, and oxygen gas which is not humidified is configured to be bypassed directly to the passage of the piping means without passing through the humidification means (14), and the humidification adjusting means ( 32) A breathing gas supply device, characterized in that the control for opening / closing the solenoid valves (54, 56, 58) of 32) is automatically performed based on the output signal of the humidity sensor (24). 2. The breathing gas supply apparatus according to claim 1, wherein the humidity sensor (24) is a relative humidity sensor capable of measuring humidity in consideration of ambient temperature. 3. The breathing gas supply apparatus according to claim 1, wherein the adsorption cylinder is filled with an adsorbent and a small amount of a hygroscopic agent. 4. A flow rate measuring means (36) is provided between the inlet end (20) of the container and the flow rate adjusting means (34) via a piping means, and an output signal of the flow rate measuring means is provided. 4. The breathing gas supply apparatus according to claim 1, wherein the flow rate value of the gas flowing through the flow rate measuring means is based on the flow rate display unit (38). .