JPH0288079A - Gas feed device for respiration - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention <Field of Application of the Invention> The present invention relates to a breathing gas supply device equipped with an automatic opening/closing valve that can operate according to a breathing cycle, and in particular to a breathing gas supply device that is equipped with an automatic opening/closing valve that can be operated according to a breathing cycle, and particularly relates to a breathing gas supply device that is equipped with an automatic opening/closing valve that can operate according to a breathing cycle. The present invention provides a device that facilitates this confirmation.

<Prior art> Oxygen therapy has traditionally been performed on patients with respiratory diseases by inhaling oxygen from an oxygen cylinder. Since oxygen concentrators were developed and put into practical use, oxygen therapy using them has gradually become popular.

Examples of such an oxygen concentrator include a pressure-fluctuating adsorption type oxygen concentrator that repeats adsorption and desorption by varying the pressure in an adsorption bed filled with an adsorbent such as zeolite that easily adsorbs nitrogen.

When supplying oxygen-enriched gas obtained from these oxygen concentrators to patients with respiratory diseases, the concentrator is usually continuously introduced into the patient's nostrils through a nasal cannula installed at the end of an extended tube. The method will be adopted.

In addition to continuous supply, methods for supplying oxygen-enriched gas have been proposed in which the oxygen-enriched gas is intermittently supplied only during inhalation according to the patient's breathing cycle, thereby preventing wasteful release of oxygen-enriched gas. (Unexamined Japanese Patent Publication No. 59-8972)
(see publication).

<Object of the Invention> The present invention provides a breathing gas supply device that is equipped with an automatic opening/closing valve (hereinafter also referred to as a demand valve) that can operate according to the breathing cycle, and which supplies breathing gas intermittently according to the breathing cycle. The purpose is to provide a system that makes it easy to set the flow rate and check the flow measurement results.

Furthermore, when supplying breathing gas intermittently, if only a flow rate setting device is used that sets the flow rate in stages by changing the flow resistance in the flow path in stages, the gas will flow out from the tip of the nasal cannula, for example. The flow rate of the gas is often difficult for the user to sense, and it is often difficult to set the flow rate of the intermittent gas if only a rotameter equipped with a flow rate adjustment valve is used, for example.

<Structure of the Invention> As a result of intensive research to achieve the above object, the present inventor has developed a flow rate setting means for setting the flow rate of breathing gas stepwise in one breathing gas supply device, and a practical method for setting the flow rate of breathing gas in stages. The present invention has been achieved by discovering that it is effective to provide both diversion display means for displaying the flow rate of breathing gas flowing through the pump and the pump in series.

That is, the present invention provides a breathing gas supply device comprising a breathing gas generating means and a supplying means for making the breathing gas from the generating means available. Automatic opening/closing valve means whose opening/closing is controlled based on the detection result of a respiratory phase detection means having a function of detecting at least a part of a predetermined phase in breathing, and a flow path through which the breathing gas passes. Equipped with a flow rate setting means for setting the flow rate by changing the resistance stepwise, and a flow rate display function for measuring and displaying the flow rate of the breathing gas.
The present invention provides a respiratory gas supply device characterized in that a quantity measuring means is provided in series.

The present invention will be explained in more detail below.

That is, preferred breathing gases in the present invention include gases obtained by concentrating oxygen in the air and oxygen.

In addition to oxygen concentrators that condense oxygen in the air, the means for generating breathing gas include cylinders filled with oxygen or oxygen-enriched gas under high pressure, and tanks filled with liquid oxygen. The items used are listed below.

Preferred oxygen concentrators include pressure fluctuation adsorption type oxygen concentrators, and the adsorbents used include zeolites, which easily adsorb nitrogen, and molecular sieve carbon, which easily adsorbs oxygen. Biolites, which selectively adsorb nitrogen, are advantageously used. Furthermore, for example, an adsorption bed filled with an adsorbent made of zeolite is usually connected to a compressor by conduit means on the inlet side.
A storage tank for oxygen enriched gas is connected to the outlet side by conduit means. Note that these conduit means are equipped with automatic opening/closing valves, and by opening and closing these valves automatically by the control means, the pressure inside the adsorption bed is increased by introducing compressed air and the nitrogen adsorption operation is performed. A series of operations are repeated, including allowing the concentrated oxygen-enriched gas to flow into the storage tank and opening the valve on the inlet side to lower the pressure inside the adsorption bed to atmospheric pressure for desorption. Although one adsorption bed may be used, two to three adsorption beds may be used in parallel.

In addition, decompression means such as a vacuum pump may be used for desorption.
The above compressor may also be used as a pressure reducing means. These compressors and the like are usually driven by electric motors, but in order to remove the heat generated by their operation, fan means are also used to generate a cooling air flow.

Furthermore, when an oxygen cylinder or a liquid oxygen storage tank is used as the generation means of the present invention, it is advantageous for application as a portable device.

The breathing gas flowing out from the generating means is led from the open supply means to the user's nose or mouth via a conduit means equipped with an automatic opening/closing valve means (demand valve). That is, by controlling the opening and closing of the demand valve in accordance with the breathing phase, it becomes possible to supply breathing gas only during the first half of the inspiratory phase, for example.

The open-type supply means in the present invention is one that supplies breathing gas to the patient's nostrils and mouth in a state that is not sealed, that is, in a state that is open to the atmosphere, and includes, for example, a nasal cannula.

A nasal cannula may also be used via a long extension tube. Although the cross-sectional shape of such an extension tube may be a perfect circle or something close to it, it is practically preferable to have an irregular cross-section other than a perfect circle because flow stoppage due to bending of the tube is less likely to occur. An example of a preferable shape of the irregular cross-section is one in which the outer side is a circle or an ellipse, and the inner side is a plurality of connected arcs of the same or different sizes. The number of circular arcs is preferably in the range of 2 to 7, and an odd number is particularly desirable from a practical standpoint because the tube is less likely to bend. Note that the arc preferably has a shape that is centered inside the tube and opens inward.

A tube having such an irregular cross section is generally advantageously used as a conduit means for supplying oxygen-enriched gas.

The automatic opening/closing valve means of the present invention, including the demand valve, is preferably a DC excited solenoid valve, an AC excited solenoid valve, an air-operated automatic valve, a pilot-operated solenoid valve, etc. Among them, a DC excited solenoid valve, an air Actuated automatic valves and pilot-operated solenoid valves, etc., have a long life due to the gentle movement of the iron core, and generate less noise during operation. Measure 1 for noise reduction is even more preferable, and DC-excited solenoid valves are especially practical. It is.

The respiratory phase detection means may be of any type as long as it can detect exhalation and exhalation cycles during breathing. A specific example is the pressure associated with airflow in the expiratory and inspiratory passages.

Examples include means for detecting values that change based on respiration, such as temperature and humidity. In addition, devices based on gas flow characteristics, such as fluid logic elements, are also required.

Detection means based on pressure must either detect pressure fluctuations or measure the pressure itself, but the above method is preferred from a practical standpoint, and in particular, a method that detects the rate of change in pressure increases sensitivity. It is very effective. As a means for detecting pressure fluctuations, for example, a pressure fluctuation detection means using a diaphragm or the like in a conduit having an opening in the nostril, which is a passage through which exhaled and inhaled air passes, can be used. Some diaphragm-type micro-pressure fluctuation detection means use metal materials such as stainless steel, but there are also diaphragm-type micro-pressure fluctuation detection means that use a metal material such as stainless steel. A method using a polymer film surface-treated with a conductive substance as a diaphragm for measuring pressure or differential pressure by changing capacitance has been rejected. In particular, in the case of a detection means using such a polymer film as a diaphragm, it is suitable for detecting slight variations in thickness and slight differential pressure of about several mmAQ. Note that a conduit that communicates with the spaces on both sides of one side of the diaphragm and whose other end opens at the nostril, etc. may be provided separately from the conduit means for supplying breathing gas to the nostril, etc.; It may also be attached to a single conduit means.

As a means for detecting temperature fluctuations, a temperature sensing member such as a thermocouple is placed in the exhalation and inhalation passages, that is, in the respiratory airflow. Furthermore, as an example of a means for detecting humidity fluctuations, a method using a hygrometer can be cited.

Among these, the pressure fluctuation detection means is convenient because it can detect the fluctuation at a position remote from the respiratory airflow such as the nostril, and in particular, the conduit means for detecting pressure fluctuation is used for supplying breathing gas. It has the advantage of being common to conduit means.

At least some of the predetermined phases in respiration detected by such a respiration phase detection means include the start of inhalation, the start of exhalation, and the like. Particularly, a device in which the start of inspiration is detected as a predetermined phase is advantageous in practical terms, since the breathing gas can be stably supplied in accordance with the intake.

The apparatus of the present invention includes a control means for automatically opening and closing the demand valve based on the detection result of the respiratory phase detection means. The control means may be any commonly used control means, such as one using a microcomputer or the like.

The breathing gas supply device of the present invention has a flow rate setting means that can set the flow rate in stages, and a flow rate display that measures and displays the flow rate. The present invention is characterized in that it is provided in series with the conduit means as the means for supplying the gas for use.

Examples of the flow m setting means include those that step-by-step change the flow resistance in the breathing gas flow path to set the flow rate in steps. Preferred specific examples include, for example:
One example includes a thin plate-like member having a plurality of independent through-holes with different diameters, and the flow rate is set by selecting one of the through-holes to allow gas to flow. Other examples include a flow rate setting device that includes a plurality of thin tubes with different hole diameters or lengths instead of a plate-like member.

Examples of flow rate measuring means with a flow rate display function include area flowmeters such as a rotameter, such as a rotameter, a piston type, and a volumetric flowmeter, such as a roots type, among which a rotameter is suitable for practical use.

When these demand valves, flow rate setting means, and flow rate measuring means are arranged in series, their order is not particularly limited, but preferably, the flow rate setting means is placed downstream of the demand valve, and the flow rate setting means is placed further downstream of the demand valve. The order in which the flow rate measuring means with a flow rate display function is arranged is practical because the flow rate can be set and displayed stably and easily.

<Effects of the Invention> The breathing gas supply device of the present invention makes it easy to set the flow rate when supplying breathing gas to the user intermittently in accordance with the breathing phase, and to easily confirm the flow rate. It has an excellent effect on

Claims (3)

[Claims] (1) In a breathing gas supply device equipped with a breathing gas generation means and a supply means for making the breathing gas from the generation means available, the supply means is provided with a respiratory gas flow rate based on a characteristic value of the respiratory airflow. Automatic opening/closing valve means whose opening/closing is controlled based on the detection result of a respiratory phase detection means having a function of detecting at least a part of a predetermined phase, and a flow resistance in a flow path through which the breathing gas passes. A flow rate setting means for setting the flow rate by changing it stepwise, and a flow rate measuring means with a flow rate display function for measuring and displaying the flow rate of the breathing gas are provided in series. Breathing gas supply device. (2) The respiratory gas supply device according to claim 1, wherein the respiratory gas generation means uses at least one selected from pressure fluctuation adsorption type oxygen concentrator means, oxygen cylinder means, and liquid oxygen storage means. . (3) The respiratory gas supply device according to claim 1, wherein the flow rate measuring means is a rotameter means.