JP3547109B2 - Method for humidifying medical gas and its supply pipe - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for humidifying a medical gas for appropriately humidifying the medical gas when supplying and inhaling a medical gas such as oxygen gas to a human body, and a method for humidifying a medical gas used for performing the method. It concerns the supply pipe.
[0002]
[Prior art]
Generally, as the medical gas, a single component gas (oxygen gas, nitrogen gas, nitrous oxide gas, carbon dioxide gas, etc.), a single component liquefied gas (liquid oxygen, liquid nitrogen, etc.) or a mixed gas thereof (for example, Synthetic air in which nitrogen gas and oxygen gas are mixed, inhalation gas for anesthesia treatment in which oxygen gas is mixed with nitrous oxide gas, etc.) are used. It is an absolutely dry state (usually, dew point under atmospheric pressure: -60 ° C, water content (volume ratio): about 10.7 ppm) which has been removed to the limit.
[0003]
That is, as the medical gas, a single-component gas or a single-component liquefied gas stored in an appropriate storage container such as a tank or a cylinder is directly vaporized (when a single-component liquefied gas is used) or mixed (such as synthetic air). When a mixed gas is used), the single-component gas or single-component liquefied gas stored in the storage container is manufactured industrially. It has been removed. Therefore, the vaporized gas of the single-component gas or the single-component liquefied gas industrially manufactured in this way or a mixed gas thereof hardly contains moisture. In some cases, the gas stored in the storage container is not used, and oxygen gas or the like generated by a PSA-type oxygen generator or the like is used as home oxygen therapy gas. The in-home oxygen therapy gas, as well as the industrially produced gas, is one from which water has been removed and is in a completely dry state.
[0004]
Therefore, supplying or inhaling such a completely dry medical gas to a patient may cause problems such as decreased ciliary movement of the upper respiratory tract mucous membrane, loss of body water and calories, and difficulty in expectoration due to drying of sputum. Generally, it is preferable that the medical gas is appropriately humidified before being supplied and inhaled to the human body. For example, the amount of water (volume ratio) in the air at 25 ° C. and 1 atm and a relative humidity of 60% is 18760 ppm, but it is preferable to humidify it to this extent.
[0005]
Therefore, a method of humidifying the medical gas by providing a baffle humidifier or a pass-over humidifier in a medical gas supply pipe has been proposed. That is, in the method using the baffle type humidifier, the medical gas is bubbled into purified water in the humidifier body from a bubbler, and the medical gas is humidified by contact with the purified water. In addition, the method using a pass-over type humidifier is to pass the medical gas over the surface of purified water stored in the humidifier body, thereby entraining the moisture in the medical gas and humidifying the vapor pressure. It is what you do.
[0006]
[Problems to be solved by the invention]
However, such a conventional humidification method has the following problems because purified water is used as a humidification source.
[0007]
That is, if the sanitary management of the purified water and the humidifier main body storing the purified water is neglected, harmful bacteria and the like may be generated and may be mixed into the medical gas. Therefore, a patient who is a medical gas user is inherently weak in resistance, and when a gas containing such harmful bacteria is supplied or inhaled, the medical gas is concomitantly infected. There was a risk of becoming a source. On the other hand, in order to ensure the sanitary management of the purified water and the humidifier body, it is necessary to frequently change the purified water and clean the humidifier body. The cost is also high.
[0008]
Further, since the purified water is consumed with the use of the medical gas, it is necessary to automatically replenish the water or keep a stock for replenishment, which requires much time and effort for maintenance and management. In addition, since the sound of bubble generation by a bubbler or the like continues, troubles such as hindering sleep are caused particularly for patients who need rest. In a portable oxygen inhaler used when going out, a small storage container storing liquid oxygen is carried. In addition to such a storage container for liquid oxygen, a humidifier (refining device) is used. Carrying a water bubbler container or the like at the same time is labor-intensive and limits the range of activity when going out. From this point, in general, when a portable oxygen inhaler is used, humidification of oxygen gas is not performed.
[0009]
The present invention provides a method for humidifying a medical gas that can safely and easily humidify a medical gas without causing such a problem, and that can be humidified maintenance-free for a long time, It is an object of the present invention to provide a supply pipe for medical gas that can be suitably used when performing this method.
[0010]
In the invention of claim 1 of the present application, in order to achieve the above object, a proximal end portion 3b connected to a gas outlet of a portable oxygen inhaler, a distal end portion 3a for supplying a medical gas to a patient, In a medical gas supply pipe 3 for supplying a medical gas to a patient, comprising a proximal end portion 3b and an intermediate portion 3c communicating between the distal end portion 3a, the intermediate portion 3c of the supply tube is connected to a chemical structure 4. One inner diameter formed of an organic polymer thin film which is a copolymer of ethylene fluoride and perfluorinated-3,6-dioxa-4-methyl-7-octene and has a sulfonic acid group coordinated as a functional group Is about 2.2 mm and the outer diameter is about 2.8 mm, and the both ends of the membrane tube 6 are inserted into the distal end portion 3a and the proximal end portion 3b of the supply pipe 3 to form a membrane. Outer wall and tip of tube 6 The three members 3a, 3b and 3c are fixed to each other by adhesives 9 and 10 filled between the inner wall surfaces of the base 3a and the base end portion 3b, and the outside of the membrane tube 6 is further protected by a protective tube 7 made of porous material. The basic configuration of the medical gas supply pipe is to humidify the medical gas passing through the membrane tube with atmospheric moisture as the coating configuration.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be specifically described with reference to FIGS.
[0013]
This embodiment is an oxygen inhaler used for relieving respiratory insufficiency such as pulmonary disease or for recovering oxygen concentration when oxygen concentration in blood is low. The present invention is applied to a portable oxygen inhaler 1 easily used in a medical facility or the like.
[0014]
As shown in FIG. 1, this oxygen inhaler 1 is provided at a storage container (vacuum insulated container) 2 for liquid oxygen, a supply pipe 3 connected to a gas outlet 2 a of the storage container 2, and a distal end of the supply pipe 3. And a cannula 4. The storage container 2 is a portable and small one, and the oxygen gas (or the oxygen gas vaporized by heat exchange with the atmosphere, if necessary) 5 in the gas phase portion in the container is supplied to the supply pipe 3 from the gas outlet 2a. Has become. The supply amount of the oxygen gas 5 can be appropriately adjusted by a dial type flow meter 2b provided in the storage container 2 according to the oxygen suction condition (for example, 2 l / min). The liquid oxygen in the storage container 2 is manufactured industrially, and the oxygen gas 5 as the vaporized gas is in the above-mentioned absolutely dry state (water content (volume ratio): about 11 ppm).
[0015]
Thus, in this embodiment, the supply pipe 3 according to the present invention is, as shown in FIGS. 1 and 2, a base end connected to a distal end portion 3a having a cannula 4 and a gas outlet 2a of the storage container 2. It is configured as a series of flexible tubes consisting of a portion 3b and an intermediate portion 3c connecting between the two portions 3a, 3b.
[0016]
That is, like the supply pipe generally used in this type of oxygen inhaler, the distal end portion 3a is a semi-transparent flexible pipe made of a synthetic resin material such as vinyl chloride (for example, inner diameter: 3 mm, outer diameter: 5 mm). And is long enough to fit the cannula 4 into the nostrils. Further, the base end portion 3b is a short cylindrical member which can be detachably fitted and connected to the gas outlet 2a of the storage container 2, and is made of the same material as the front end portion 3a.
[0017]
Further, as shown in FIG. 2, the intermediate portion 3c is composed of a water-molecule-permeable membrane tube 6 capable of transmitting water molecules preferentially, and is covered with a protective tube 7 made of a porous material. The membrane tube 6 has its both ends fixedly connected to the distal end portion 3a and the proximal end portion 3b by adhesives 9 and 10, such as epoxy resin, and has a main chemical structure of ethylene tetrafluoride and perfluorinated 3,4. An organic polymer thin film which is a copolymer with 6-dioxa-4methyl-7-octane and to which a sulfonic acid group is coordinated as a functional group is formed into a thin tube shape (for example, inner diameter: 2.2 mm, outer diameter: 2.8 mm) It has a selectivity that allows only water molecules to pass through, as described later. The protective tube 7 is a porous flexible tube formed by circularly knitting a high-strength yarn such as a metal yarn or a polypropylene fiber yarn into a tubular shape. The membrane tube 6 is fixed to the distal end portion 3a and the proximal end portion 3b together with the tube 6 with adhesives 9 and 10 to reinforce and protect the membrane tube 6 while allowing contact with the atmosphere. The length of the membrane tube 6 is appropriately set according to humidification conditions and the like, and its wall thickness (film thickness) takes into consideration the water molecule permeation function (the thinner the film thickness, the greater the water molecule permeation amount). In addition, the pressure is set to an extent that can sufficiently withstand the supplied oxygen gas pressure.
[0018]
The humidification method according to the present invention is carried out as follows using the supply pipe 3.
[0019]
Oxygen gas 5 is inhaled from the gas outlet 2a of the storage container 2 through the supply pipe 3 through the cannula 4 into the nostrils of the patient, and this oxygen gas 5 passes through the middle part 3a of the supply pipe 3, that is, the inside of the membrane tube 6. In the meantime, it is humidified to the same degree as the atmosphere outside the supply pipe 3.
[0020]
That is, as described above, the membrane tube 6 has a main chemical structure of a copolymer of ethylene tetrafluoride and perfluorinated 3,6 dioxa-4methyl-7 octane, and coordinates a sulfonic acid group as a functional group. Although the sulfonic acid group (—SO ₃ H), which is a functional group in this thin film, is a hydrophilic group, the outer surface of the membrane tube 6 is exposed to air in contact with the thin film. water molecules (moisture present as water vapor) and rapidly chemisorption in, absorb as sulfonic acid hydrate _{(-SO 3 H · [H 2} O] n).
[0021]
The water molecules absorbed on the outer surface of the membrane tube 6 permeate (move) through the thin film as the tube wall of the membrane tube 6 due to the difference in the vapor partial pressure of the water molecule between the inside and the outside of the membrane tube 6. It diffuses into the oxygen gas 5 in the absolutely dry state flowing through the inside 6. By the way, the amount of water (volume ratio) in the atmosphere at room temperature (25 ° C.) is about 19000 ppm, which is about 1700 times the oxygen gas 5 (moisture amount (volume ratio): about 11 ppm) flowing in the membrane tube 6. However, since the vapor partial pressure of the water molecule is proportional to the content of the water molecule, the vapor partial pressure of the water molecule in the gas (atmosphere) outside the membrane tube 6 is the same as the gas (oxygen gas) in the membrane tube 6. Is about 1700 times the vapor partial pressure of water molecules at Therefore, such a large difference in the vapor partial pressure of the water molecules between the inside and the outside of the membrane tube 6 becomes a driving hose, and the speed at which the water molecules permeate the membrane tube 6 is extremely fast, and the oxygen gas 5 flows through the membrane tube 6. During the passage, the oxygen gas 5 is humidified very quickly and sufficiently. This will be easily understood from the embodiments described later.
[0022]
On the other hand, as is well known, the tetrafluoroethylene copolymer, which is the main structure of the constituent material (organic polymer thin film) of the membrane tube 6, hardly transmits gas molecules other than water molecules. Bacteria such as bacteria and viruses larger than gas molecules do not pass through the membrane tube 6. In other words, even if such cells exist in the atmosphere, there is no danger that they will enter the membrane tube 6 and be mixed into the oxygen gas 5, and even if they are used continuously for a long period of time, they will be hygienic. No problem is caused.
[0023]
Therefore, the oxygen gas 5 which is almost as wet as the atmosphere and does not contain bacteria in the atmosphere is inhaled from the cannula 4 into the nostrils of the patient, and places a burden on the upper respiratory tract and lungs of the patient due to drying. Without this, oxygen inhalation therapy can be performed safely. Further, since only water is collected from the atmosphere in contact with the membrane tube 6, unlike the case where water is collected from purified water, it is maintenance-free and oxygen inhalation can be performed extremely easily. Needless to say, there is no need for the cost and labor required for the exchange and replenishment of purified water, and the oxygen can be inhaled in a quiet state without the sound of generating bubbles, and does not hinder sleep of the patient.
[0024]
Also, when going out, it is possible to carry out good oxygen inhalation with the humidified oxygen gas 5 only by carrying the storage container 2 alone. Therefore, it is possible to go out in the same way as a healthy person without being affected by the burden of labor and restrictions on the range of action such as carrying a humidifier (bubbler container of purified water or the like) at the same time as in the related art.
[0025]
Note that the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention.
[0026]
In other words, the present invention is applicable to any medical gas which has some problems (such as a decrease in upper airway ciliary movement) when used in a completely dry state as described above, and is preferably used after being appropriately humidified. Can be. For example, in addition to oxygen gas, a single component gas such as nitrogen gas, nitrous oxide gas, carbon dioxide gas (including those used by vaporizing these liquefied gases) or a mixture of two or more of these gases It can be applied when humidifying air, inhalation gas for anesthesia treatment, and the like. Further, the present invention provides not only the humidifying method and the supply pipe in the portable oxygen inhaler described above, but also the humidifying method in various medical gas supply devices such as a large oxygen inhaler and an anesthesia treatment device installed in a hospital or the like. Similarly, the present invention can be suitably applied to a supply pipe.
[0027]
Further, in the above-described embodiment, a part 3 c of the supply pipe 3 is configured by the membrane tube 6 permeable to water molecules, but the entire supply pipe 3 including the cannula 4 is configured by the membrane tube 6. It may be.
[0028]
In addition, the present invention is suitable as described above, even when the supply pipe is not in contact with the atmosphere, as long as the supply pipe is in contact with a humid gas similar to the atmosphere (such as exhaled gas discharged from the human body). Can be applied to For example, in an anesthesia treatment apparatus having a respiratory circuit connected to a mask or the like, the respiratory circuit may be configured as an integral structure (a double tube structure in which an inspiratory tube is arranged in an expiratory tube). A part or all of an intake pipe, which is a supply pipe for supplying a mixed gas (anesthetic gas) of nitric oxide gas and oxygen gas, is constituted by a water-molecule-permeable membrane tube 6, and water molecules permeate from the exhaled gas in the expiratory tube. By doing so, the medical gas (anesthetic gas) in the membrane tube 6 can be humidified.
[0029]
When two or more single-component gases (source gases) are mixed and used as in the case of the above-mentioned anesthetic gas, at least a part of the supply pipe for the mixed gas is constituted by a water-molecule-permeable membrane tube 6. Alternatively, at least a part of the source gas supply pipe may be constituted by a water molecule permeable membrane tube 6 so that the source gas before mixing is humidified.
[0030]
When a part of the supply pipe is constituted by the water-molecule-permeable membrane tube 6, the selection of the part is optional, but it is preferable to avoid the part that moves frequently as much as possible. Of course, when the atmosphere or a similar wet gas is only in contact with a part of the supply pipe, the contact part is naturally constituted by the membrane tube 6 permeable to water molecules.
[0031]
The constituent material of the membrane tube 6 is the above-mentioned organic polymer thin film (main chemical structure) which is most excellent in water molecule adsorbing property, high-speed mobility, and selectivity not allowing gas molecules other than water molecules (such as oxygen gas) to permeate. Is a copolymer of ethylene tetrafluoride and perfluorinated 3,6 dioxa-4methyl-7 octane, and is preferably an organic polymer thin film having a sulfonic acid group coordinated as a functional group). However, depending on the humidification conditions of oxygen gas, it is also possible to use a polysiloxane polycarbonate-based, brominated polycarbonate-based, polysulfone-based, polymethylpentene-based, or polyimide-based hollow fiber membrane known as a so-called oxygen permeable membrane. is there. When the membrane tube 6 is formed of such a hollow fiber membrane, a part or all of the supply pipe 3 is not formed of one membrane tube 6 because the membrane tube 6 is an extremely thin tube. It consists of a bundle of the membrane tubes 6. Of course, even when the membrane tube 6 is made of the above-mentioned organic polymer thin film, a part or all of the supply pipe 3 is formed by bundling a plurality of membrane tubes 6 depending on the flow rate and pressure of the medical gas. Can be configured.
[0032]
Further, the protection tube 7 may be constituted by a porous hard tube when the supply tube portion constituted by the membrane tube 6 does not require flexibility.
[0033]
【Example】
In the oxygen inhaler 1 shown in FIGS. 1 and 2, “Myself 2” (liquid volume: 1.22 l, gas volume: 1050 l) of Taiyo Toyo Oxygen Co., Ltd. The distal portion 3a (and the proximal portion 3b) are made of a vinyl chloride pipe having an inner diameter of 3 mm and an outer diameter of 5 mm, and the intermediate portion 3c is made of a material whose main chemical structure is ethylene tetrafluoride and 3,6 dioxa-4-methyl perfluoride. A membrane tube made of an organic polymer thin film (“NAFION” manufactured by PERMA PURE INC.) Which is a copolymer with 7-octane and to which a sulfonic acid group is coordinated as a functional group (inner diameter: about 2 0.2 mm (0.085 in), outer diameter: about 2.8 mm (0.110 in), length: about 609 mm (24 in)) 6.
[0034]
Then, the oxygen gas amount is adjusted to 2 l / min by the flow meter 2b, and the oxygen gas 5 (dew point: -50 ° C) is supplied to the cannula 4 under the condition that the atmosphere outside the supply pipe 3 is 22 ° C and the humidity is 55%. , And at the same time, measurement of the humidity and temperature of the gas 5 released from the cannula 4 was started, and thereafter, the measurement was continued.
[0035]
As a result, several seconds after the start of the measurement, the humidity of the released gas 5 became 49.2%, and the temperature was 22 ° C. Thereafter, the humidity of the released gas 5 was stabilized in the range of 48.5 to 49.5%. Therefore, according to the membrane tube 6, it is confirmed that humidification by collecting moisture from the atmosphere is performed very quickly and sufficiently. Further, when the amount of water collected from the atmosphere into the membrane tube 6 is calculated based on the measurement result, the amount is 19.403 mg / l × 49.2% −0.03822 mg / l = 9.508 mg / l. It is understood that 6 exerts an extremely effective humidifying function.
[0036]
【The invention's effect】
As can be easily understood from the above description, according to the method for humidifying medical gas of the present invention, at least a part of the supply pipe for medical gas is formed of a water molecule-permeable membrane tube, and the membrane tube is Since only water molecules are allowed to pass through the membrane tube membrane from the contacting atmosphere or a similar wet gas and diffused into the absolutely dry gas inside, the humidification of the medical gas can be performed without the need for purified water. It can be performed very simply and maintenance-free satisfactorily.
[0037]
Moreover, since the membrane tube hardly transmits gas molecules other than water molecules, bacteria such as bacteria and viruses larger than the gas molecules do not pass through the membrane tube. In other words, even when such bacteria are present in the atmosphere, there is no danger that they will enter the membrane tube and be mixed into the medical gas, and even if they are used continuously for a long period of time, they will be hygienic. Safe humidification can be performed without causing any problem. Therefore, oxygen inhalation therapy or the like can be safely performed without placing a burden on the upper respiratory tract or lungs of the patient due to dryness.
[0038]
In addition, the cost and labor required for replacement and replenishment of purified water are not required at all, and oxygen can be inhaled in a quiet state without the generation of air bubbles, which does not hinder sleep of the patient.
[0039]
In addition, when going out, the humidifying gas can be inhaled simply by carrying a portable storage container storing liquid oxygen or the like, so that a humidifier (such as a bubbler container for purified water) is carried at the same time. It is possible to go out the same way as a healthy person without going through the burden of labor and restrictions on the range of action.
[0040]
Further, according to the supply pipe for medical gas of the present invention, the above-described method can be suitably performed.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an oxygen inhaler provided with a medical gas supply pipe according to the present invention.
FIG. 2 is a vertical sectional side view of the supply pipe.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Oxygen inhaler, 2 ... Storage container, 2a ... Gas outlet, 3 ... Supply pipe, 3b ... Intermediate part (part of supply pipe), 4 ... Cannula, 5 ... Oxygen gas (medical gas), 6 ... Membrane tube , 7 ... Protective tube.

Claims (1)

A proximal portion (3b) connected to a gas outlet of the portable oxygen inhaler, a distal portion (3a) for supplying a medical gas to a patient, and communication between the proximal portion (3b) and the distal portion (3a). In a medical gas supply pipe (3) for supplying a medical gas to a patient comprising an intermediate part (3c), the intermediate part (3c) of the supply pipe has a chemical structure of ethylene tetrafluoride. One inner diameter of about 2.2 mm formed of an organic polymer thin film which is a copolymer with fluorinated-3,6-dioxa-4-methyl-7-octene and to which a sulfonic acid group is coordinated as a functional group And a membrane tube (6) having an outer diameter of about 2.8 mm, and having both ends of the membrane tube (6) inside the distal end portion (3a) and the proximal end portion (3b) of the supply pipe (3). Into the outer wall and the tip of the membrane tube (6) The three members (3a), (3b), and (3c) are fixed to each other by the adhesives (9) and (10) filled between the inner wall surfaces of the base member (3a) and the base end portion (3b). 6) A medical gas supply pipe characterized in that a medical gas passing through the membrane tube is humidified by moisture in the air, wherein the medical gas is humidified by atmospheric moisture.

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