JP3790380B2 - Medical oxygen concentrator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an oxygen concentrator for separating and using an oxygen-enriched gas (including oxygen-enriched air) from the atmosphere. More particularly, the present invention relates to an improved medical oxygen concentrator that can supply a user with oxygen-concentrated gas that has been humidified using moisture in the air. It is to provide.
[0002]
[Prior art]
In recent years, there has been an increase in the number of patients suffering from respiratory diseases such as asthma, emphysema, and chronic bronchitis. One of the most effective treatments is oxygen inhalation therapy. Oxygen concentrators that directly separate the gas have been developed, and are becoming increasingly popular as therapeutic devices for oxygen inhalation therapy because of convenience during use and ease of maintenance.
[0003]
As such a medical oxygen concentrator, a membrane separation type oxygen concentrator using an oxygen selective permeable membrane and an adsorption type oxygen concentrator using an adsorbent capable of selectively adsorbing nitrogen or oxygen are known. Furthermore, there is an apparatus that electrochemically generates oxygen using a solid electrolyte membrane that selectively permeates oxygen ions. As an adsorption type oxygen concentrator, there is a pressure fluctuation adsorption type oxygen concentrator using a compressor. Usually, compressed air is introduced into an adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen and pressurized. An apparatus that obtains oxygen-enriched gas by alternately performing an adsorption process that obtains oxygen-enriched gas by adsorbing nitrogen in a state and a desorption process that desorbs nitrogen by reducing the internal pressure of the adsorption bed and regenerates the adsorbent is there.
[0004]
The oxygen-enriched gas generated by such a pressure fluctuation adsorption method shows a dry state that is almost completely dry. If such a gas is inhaled by the user for breathing, the inside of the respiratory tract, especially the nostrils and throat, may become uncomfortable, and if it reaches directly to the lungs, the mucous membrane may be damaged and the physical condition may be damaged. There is a problem, and it is necessary to humidify separately to prevent this problem.
[0005]
As such a humidifier, water is put into a sealed vessel, a bubbling humidifier that passes oxygen-enriched gas into the water, and an evaporative type that passes oxygen-enriched gas over the water surface and humidifies with evaporated moisture There is a humidifier. All of these use water, and the user always needs to replenish and replace the water in the humidifier and manage the humidified water such as washing to prevent the generation of germs. This results in new problems such as leakage of oxygen-enriched gas from the humidifier attachment / detachment part after replacement.
[0006]
As a method for solving these problems, an oxygen concentrator equipped with a membrane humidifier that uses a water vapor permeable hollow fiber membrane described in JP-A-2-99113 and humidifies oxygen-enriched gas has been considered. Such oxygen concentrators humidify the oxygen-enriched gas by using either water in the raw material pressurized air or water in the regeneration gas of the adsorption tower.
[0007]
In such an apparatus, since all the raw material pressurized air is supplied to the adsorption tower after being supplied to the module loaded with the water vapor permeable hollow fiber, it is difficult to adjust the humidification, especially when the product oxygen flow rate is low. , There is a problem of excessive drainage and drainage.
[0008]
On the other hand, as described in JP-A-5-49697, a method of dehumidifying excess water using another membrane humidifier (dehumidifier) and discarding it as a drain, or JP-A-8-196635 As described, a method of adjusting the humidification by providing a bypass route in the route of humidifying the product oxygen gas has been found. However, it is difficult to control the humidification required by either method, and there are many problems such as requiring a plurality of membrane-type humidification (dehumidification) modules, complicated piping systems, and flow control systems.
[0009]
Furthermore, an oxygen concentrator described in JP-A-9-276408 has been considered as a method of directly bringing the hollow fiber into contact with humidified water and supplying moisture to oxygen flowing through the hollow fiber. However, even in this method, humidified water is excessive, and there are problems such as generation of drain and adjustment of humidification, difficulty in handling such as replacement of humidified water, and the like.
[0010]
[Problems to be solved by the invention]
The present invention solves various problems that occur in an oxygen concentrator equipped with a conventional moisture permeable membrane humidifier, does not require replenishment or replacement of water, and is at the same level as the relative humidity of atmospheric air or It is an object of the present invention to provide a medical oxygen concentrating device having a humidifying means for breathing gas that humidifies further.
Furthermore, it aims at providing the medical oxygen concentration apparatus provided with the humidification means which prevents clogging of a hollow fiber-like water-permeable membrane.
[0011]
[Means for Solving the Problems]
As a result of earnestly examining the above problems, the applicant of the present application is an apparatus for humidifying an oxygen-enriched gas by using atmospheric air instead of raw material pressurized air as a moisture supply source of a hollow fiber membrane humidifier. Is found.
[0012]
That is, the present invention includes at least one adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen over oxygen, an air supply means for supplying air to the adsorption bed, and an oxygen-enriched gas from the adsorption bed In a medical oxygen concentrating apparatus comprising a moisture permeable membrane means for humidifying the gas and a throttle means for controlling the flow rate of the breathing gas, the moisture permeable membrane means is installed in a region upstream of the throttle means The present invention provides a medical oxygen concentrating device.
[0013]
The present invention also provides a medical oxygen concentrator characterized in that the upstream region of the throttle means is in a positive pressure state of 10 to 50 kPa.
[0014]
The present invention further comprises a pressure adjusting means for maintaining a constant pressure upstream of the throttling means and a filter means for removing foreign matters such as dust, and the moisture permeable membrane means is installed between the filter means and the throttling means. The present invention provides a medical oxygen concentrator characterized by the above.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred specific examples of the oxygen concentrator of the present invention will be described with reference to the drawings as necessary. However, the present invention is not limited to these examples.
[0016]
The membrane humidifier provided with the moisture permeable membrane means of the oxygen concentrator of the present invention is not particularly limited. However, the membrane water vapor permeation principle is roughly divided into non-porous materials that allow moisture to permeate using a water vapor partial pressure difference. There are two types: a high-quality dissolved diffusion membrane and a microporous membrane that selectively permeates water vapor molecules based on the principle of molecular sieving.
[0017]
As a material, it is preferable to use a fluorine-based resin film from the viewpoint of the strength of the film and the water permeation efficiency. In particular, SUN SEP-W manufactured by Asahi Glass Co., Ltd., NAFION manufactured by DuPont, membrane manufactured by Ube Industries, Ltd., and the like are preferable. This material is often used as an antibacterial resin and is suitable for medical use. However, the resin is not limited to the fluororesin as long as it is a resin material exhibiting the physical properties.
[0018]
Such a membrane is a hollow fiber membrane, and a hollow fiber having an inner diameter of several μm to several mm is used. However, if the membrane is too thin, clogging is likely to occur, and a hollow fiber having a diameter of 1.0 to 5.0 mm is used. Is preferred.
[0019]
The length of the hollow fiber is preferably at least 10 cm or more, and preferably 10 to 100 cm when used as a medical oxygen concentrator. Although it is possible to use a thing of 100 cm or more, since pressure loss occurs, it is necessary to consider such as limiting the flow rate, and using a plurality of hollow fibers of 100 cm or less in parallel reduces pressure loss. This is advantageous in terms of downsizing.
[0020]
The humidifier used in the present invention is a module using such a hollow fiber, and a dry oxygen-enriched gas is passed through the inside of the hollow fiber and the outside is placed in a state open to the atmosphere. The hollow fiber itself is preferably provided with a mesh-structured reinforcing material to ensure strength.
[0021]
Further, as a feature of the moisture permeable membrane used in the present invention, the moisture permeation rate has temperature dependency, and it becomes possible to instantaneously obtain the target humidification by increasing the use environment temperature. Furthermore, by utilizing this characteristic, the number and length of the moisture permeable membranes can be reduced, leading to a cost reduction of the relatively expensive moisture permeable membrane.
[0022]
The oxygen concentrator of the present invention is characterized in that the moisture permeable membrane means is installed in a region upstream of the throttling means. Upstream of such stop means are dry oxygen enriched gas is in the positive pressure state, it is possible to increase the humidification of the oxygen enriched gas. Further, the oxygen-enriched gas generated from the adsorption bed repeats pressure fluctuations with a constant width, and it is preferable to install a pressure adjusting means for adjusting the pressure at a constant pressure value on the upstream side of the throttle means. Thereby, the humidification fluctuation | variation by a pressure fluctuation | variation can be prevented and it becomes possible to obtain oxygen concentration gas of fixed humidity.
[0023]
As such a throttle means, means for controlling the flow rate of the oxygen-enriched gas can be used, and a method of controlling with an orifice is preferred. In this case, the upstream region needs to have a constant differential pressure at the orifice portion, and it is preferable to maintain a positive pressure state of 10 to 50 kPa.
[0024]
Further, in order to prevent foreign matters such as dust from entering the orifice portion on the upstream side of the squeezing means, foreign matter removing filter means is installed, and in particular, the filter means on the upstream side of the squeezing means and the moisture permeable membrane means. It is preferable to install. Thereby, clogging of the hollow fiber-like moisture permeable membrane means and contamination of the membrane surface can be prevented, and a decrease in moisture permeability efficiency can be prevented.
[0025]
In addition, the air supply means used in the oxygen concentrator of the present invention uses an oxygen concentrator functioning as a compressor means for supplying raw air to the adsorption bed in the adsorption step.
[0026]
Further, in the oxygen concentrator using the present invention, the adsorbent bed may be either one or two or more. In the case of a small oxygen concentrator for medical use, in particular, the case of one is the entire apparatus. It is excellent in terms of easy compactness, high concentration efficiency, and durability.
[0027]
In general, a cooling fan is used in the oxygen concentrator to make the temperature inside the apparatus constant, such as a compressor and an adsorption bed, and this cooling air is supplied to the atmosphere side of the moisture permeable membrane means of the apparatus of the present invention. In order to obtain the humidity, it is configured to apply the moisture-rich desorption air generated in the adsorption bed desorption process to the atmosphere side of the membrane humidifier of the apparatus of the present invention. Is preferred.
[0028]
The present invention is a pressure fluctuation adsorption type oxygen concentrator equipped with a membrane-type humidifier. However, the present invention relates to an oxygen supply device that uses an oxygen cylinder that is a dry gas as a supply source, and an oxygen supply device that uses a solid electrolyte membrane as an oxygen supply source. It can also be applied to.
[0029]
【Example】
Hereinafter, it demonstrates still in detail using drawing.
FIG. 1 shows a preferred embodiment of the present invention. In other words, it is equipped with a compressor that supplies pressurized air to a single adsorption tower packed with zeolite-based adsorbent as an adsorbent that selectively adsorbs nitrogen. After storing non-adsorbed concentrated oxygen in a surge tank, the orifice flow rate is set. Oxygen-concentrated gas that has passed through a pressure-regulating valve and filter that keeps the pressure constant upstream of the vessel is humidified through a humidifying means equipped with a moisture-permeable hollow fiber membrane, and oxygen is supplied to the patient after adjusting the flow rate with the flow rate setting device Is done.
[0030]
As such a moisture permeable hollow fiber membrane, a non-porous fluororesin-based dissolution diffusion membrane (NAFION manufactured by DuPont) that transmits moisture using a partial pressure difference of water vapor is used. Six hollow fibers having an inner diameter of 1.5 mm and a length of 60 cm were used as parallel bundles. The humidifying means is in contact with the outside air by a cooling fan inside the medical oxygen concentrator.
[0031]
The humidification of the oxygen concentration gas supplied from the oxygen concentration apparatus concerning FIG. 2 is shown. The horizontal axis represents the flow rate setting value of the medical oxygen concentrator, and the vertical axis represents the humidification of the oxygen-enriched gas. As a result, the oxygen concentrator of the present invention can supply the oxygen-enriched gas humidified to near the operating environment humidity at each set flow rate.
[0032]
【The invention's effect】
In the oxygen concentrator of the present invention, a hollow fiber membrane humidifier can be used to humidify medical oxygen-enriched air without having to replenish water. Further, in the humidifying means of the oxygen concentrator of the present invention, the oxygen-enriched air supplied to the patient exhibits almost the same humidification as the air in the atmosphere without a flow control system for adjusting the humidification amount. it can.
[0033]
In such oxygen-enriched air, the humidity of the oxygen-enriched air naturally changes as the humidity of the outside air changes, but it is possible to maintain the same level of humidification as the air that a normal person is breathing. However, since there is also a drying effect by the flow of oxygen-enriched air, the oxygen-enriched air supply flow rate of the oxygen concentrator is preferably used at 5 L / min or less.
[0034]
Furthermore, when an oxygen-enriched gas having a higher humidity than the ambient air humidity is required, it can be combined with a conventionally used humidification method (evaporation type, bubbling type, etc.).
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing the configuration of a medical oxygen concentrator according to the present invention.
FIG. 2 shows humidification characteristics of the oxygen-enriched gas humidified by the humidifying means of the medical oxygen concentrator of the present invention.

Claims (4)

At least one adsorption bed filled with an adsorbent capable of selectively adsorbing nitrogen than oxygen, and air supply means for supplying pressurized air to the adsorption bed, for humidifying the oxygen enriched gas from the adsorption bed In the medical pressure fluctuation adsorption type oxygen concentrator equipped with the moisture permeable membrane means and the throttle means for controlling the flow rate of the oxygen-enriched gas, the moisture permeable membrane means is installed in a region upstream of the throttle means. A pressure fluctuation adsorption type oxygen concentrator for medical use, which takes in moisture in air at atmospheric pressure . The medical pressure fluctuation adsorption type oxygen concentrator according to claim 1, wherein the air is air for cooling the apparatus and / or desorption air of the adsorption bed. The medical pressure fluctuation adsorption type oxygen concentrator according to claim 1 or 2, wherein the oxygen-enriched gas in the upstream region of the throttle means is maintained in a positive pressure state of 10 to 50 kPa. A pressure regulating means for keeping the pressure constant and a filter means for removing foreign substances are provided upstream of the throttling means, and the moisture permeable membrane means is installed between the filter means and the throttling means. Item 4. The medical pressure fluctuation adsorption oxygen concentrator according to items 1 to 3.

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