JP2834717B2 - Respiratory gas supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a respiratory gas supply device provided with an automatic on-off valve operable according to a respiratory cycle. Particularly preferably, the present invention relates to an oxygen-enriched gas supply device using a pressure fluctuation adsorption-type oxygen concentrator, which is provided with an automatic on-off valve that can be operated according to a breathing cycle.

[0002]

2. Description of the Related Art Conventionally, oxygen therapy has been performed by inhaling oxygen from an oxygen cylinder for a patient with respiratory disease. In particular, recently, oxygen therapy in order to obtain oxygen-enriched gas by concentrating oxygen in the air has been performed. Since oxygen concentrators have been developed and put into practical use, oxygen therapy using the oxygen concentrators has become increasingly popular.

[0003] Such oxygen concentrators are roughly divided into adsorption-type oxygen concentrators of a pressure fluctuation type or the like in which adsorption and desorption are repeated by changing the pressure in an adsorption tower packed with an adsorbent such as zeolite, which more easily adsorbs nitrogen. And a membrane oxygen concentrator using an oxygen selective permeable membrane.

[0004] When supplying oxygen-enriched gas obtained by these oxygen concentrators to a patient with respiratory disease, the nasal cannula provided at the end of a tube usually extending from the concentrator is continuously used to supply the patient's nares. The method introduced inside is adopted. In addition, as an improved supply system, it is possible to supply oxygen-enriched gas only during inhalation in response to the patient's respiratory cycle, thereby preventing wasteful oxygen-enriched gas release and improving efficiency. (Japanese Patent Laid-Open No. 59-8972).

[0005]

SUMMARY OF THE INVENTION The present invention relates to a respiratory gas supply device comprising an automatic on-off valve operable in accordance with a respiratory cycle and capable of supplying oxygen-enriched gas only during inhalation. This is a device that supplies an oxygen-enriched gas that is advantageous for patient treatment and that does not cause discomfort.

[0006]

A respiratory gas supply device according to the present invention has a respiratory gas generating means, and one end communicates with the generating means and the other end has an open type respiratory gas supplying means. Conduit means having automatic opening / closing valve means on the way, breathing phase detecting means having a function of detecting at least a part of a predetermined phase in breathing, and automatic opening / closing valve means based on a detection result of the detecting means. In a respiratory gas supply device provided with a control means for controlling opening and closing, a cushion tank means is provided upstream and / or downstream of the automatic opening and closing valve means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred examples of these devices include those in which the respiratory gas is oxygen or oxygen-enriched gas, and the means for generating the gas is an oxygen concentrator, an oxygen cylinder, or a liquid oxygen storage tank. In particular, those using a pressure fluctuation adsorption type oxygen concentrator as a generating means can be advantageously used practically.

[0008] The open-type supply means in the present invention supplies respiratory gas in a state where it is not sealed to the patient's nostrils and mouth, that is, in a state where it is open to the atmosphere. For example, a nasal cannula is used as an example. Can be

The automatic opening / closing valve means is preferably a DC-excited solenoid valve, an AC-excited solenoid valve, an air-operated automatic valve, a pilot-operated solenoid valve, or the like.
Air-operated solenoid valves, pilot-operated solenoid valves, etc. have a slow movement of the iron core, etc., have a long life, are low in noise generated during operation, and are more preferable in terms of noise reduction measures. is there.

As the respiratory phase detecting means, any means can be used as long as it can detect the cycle of expiration and inspiration during breathing. As a specific example, there is a means for detecting a value that changes based on breathing, such as pressure, temperature, and humidity, related to an airflow in an expiration and inspiration passage. Other examples include those based on gas flow characteristics such as fluid logic elements.

There are two types of pressure-based detection means: one for detecting pressure fluctuations and one for measuring the pressure itself.
The former is practically preferable, and the one that detects the rate of change of pressure is particularly effective in increasing the sensitivity. As a means for detecting the pressure fluctuation, for example, a pressure fluctuation detecting means using a diaphragm or the like in a conduit having an opening in a nostril or the like, which is a passage through which expiration and inspiration passes, may be mentioned. Some diaphragm type minute pressure fluctuation detecting means uses a metal material such as stainless steel, but other static pressure fluctuation detecting means as described in Japanese Patent Application No. 62-175982 previously filed by a part of the inventors of the present invention. Examples of the diaphragm include a polymer film surface-treated with a conductive substance for measuring a pressure or a differential pressure based on a change in capacitance. In particular, in the case of a detecting means using such a polymer film as a diaphragm, it is suitable for detecting a fluctuation of a small pressure or a small differential pressure of about several mmAq. The conduit communicating with the space on one surface side of the diaphragm and having the other end open in the nostril may be provided separately from conduit means for supplying respiratory gas to the nostril. May be provided on a single conduit means.

Means for detecting temperature fluctuations include a means for placing a temperature sensing member, such as a thermocouple, in a passage for exhalation and inspiration, that is, in a respiratory airflow. Further, as an example of the means for detecting a change in humidity, a method using a hygrometer is given.

Among these, the pressure fluctuation detecting means is convenient because the fluctuation can be detected at a position distant from the respiratory airflow such as a nostril. In particular, the conduit means for detecting the pressure fluctuation supplies the breathing gas. There is an advantage that can be shared with the conduit means for carrying out.

The predetermined phase of at least a part of the respiration detected by the respiration phase detecting means includes a time when inspiration starts and a time when expiration starts. In particular, detection of the start of inspiration as a predetermined phase is practically advantageous because the supply of breathing gas can be stably performed in response to inspiration.

In the normal operation, the respiratory gas supply device of the present invention opens and closes the automatic on-off valve means V provided in the middle of the respiratory gas supply conduit based on the detection result by the respiratory phase detection means. , The respiratory gas is intermittently supplied at least in part of the inspiratory phase.

FIG. 1 shows an example of a preferred embodiment of the respiratory gas supply device of the present invention. The oxygen-enriched gas obtained from the pressure fluctuation adsorption-type oxygen concentrator 1, which is a means for generating a breathing gas, passes through a cushion tank 2, an automatic opening / closing valve means 3, and a conduit means 5 having a cushion tank 4, and is supplied by an open supply means. Released from a nasal cannula 7.

The pressure fluctuation in the respiration is converted to the fluctuation of the capacitance by the respiration phase detecting means 9 provided with a diaphragm type small pressure fluctuation sensor provided at the branch from the conduit means 5, and the conversion circuit 12 in the control means 10. The change in capacitance is converted into an electric pulse signal by the
By means of 14, the electric pulse signal becomes a signal of the number of pulses per unit time.

Using the digital signal obtained in this way, the intake start point detecting means 16 in the CPU 11 such as a microcomputer calculates the amount of variation of the digital signal with respect to time, that is, the differential value, and sets the value to a predetermined value. If it is larger than the value, it is detected as the intake start point. The predetermined value is set by the intake detection sensitivity setting storage means 18, and is preferably set by an external input.

The time T during inspiration starting point according intake beginning and at the immediately preceding breath cycle is determined by the respiratory cycle length measuring means 20, the predetermined time T ₁ of the from the storage unit 22 for a predetermined time T ₁ by external input And the time T are compared by the comparing means 24.

If T is not greater than T ₁ , the basic time T ₀ for opening the on-off valve 3 is determined by the calculating means 26, and an extra time α inputted by the external input means 27 is added. The opening time (T ₀ + α) of the on-off valve 3 is obtained by the valve opening time determining means 28, and the valve 3 is opened and closed in each respiratory cycle by the valve opening and closing means 30.

The calculating means 26 obtains the time T ₀ by, for example, dividing the entire time of the previous N breathing cycles into N equal parts and averaging the time of one cycle by 1/3. Alternatively, it may be simply obtained by multiplying the time of the previous one cycle by 1/3. The value of N is, for example, 1 to
It is selected from 10 ranges.

It is preferable that the cushion tank 2 is also used as a cushion tank provided downstream of the adsorption bed when the generating means is a pressure fluctuation adsorption type oxygen enricher. It is easy to supply a relatively large amount of gas only at the start, which is advantageous for the patient's breathing. Further, the cushion tank 4 may not be provided, but it is preferable to provide the cushion tank 4 because the sudden fluctuation of the gas flow is eliminated and the feeling of discomfort in breathing is reduced.

This relationship is achieved by combining the cushion tanks 2 and 4 with different capacities so that various pulse shapes of the oxygen-enriched gas can be realized, which is advantageous for the treatment of the user. In addition, a pulse shape that does not cause discomfort can be selected.

As one specific example of a preferred embodiment of the means for generating respiratory gas of the present invention, at least one adsorption bed filled with an adsorbent for selectively adsorbing nitrogen gas is pressurized to the adsorption bed. A compressor means for inflowing air, and a conduit means in the enricher for taking out oxygen-enriched air from the adsorbent bed and flowing it to an outlet;
A pressure-fluctuation adsorption type oxygen enricher in which more than one adsorption bed is operated so as to repeat a pressurization-decompression cycle singly or alternately. It is preferable that any of the oxygen-enriched gas generating means has a means for adjusting the flow rate of the oxygen-enriched air to be used. In this case, for example, a flow rate setting unit that includes a plurality of openings having different hole diameters and selects the openings to set the flow rate, and a combination of a normal rotor meter type flow meter and the flow rate setting device, facilitate the flow rate setting, and This is practically advantageous because the flow state of the gas can be easily confirmed.

In the case of the present invention, the supply of breathing gas is intermittent in the normal operation mode, so that it is not necessary to use a special humidifier.

[0026]

The respiratory gas supply device of the present invention is provided with an automatic on-off valve which can be operated according to the respiratory cycle, and can provide an intermittent flow which is comfortable for the user without any discomfort to the user. It has excellent effects.

[Brief description of the drawings]

FIG. 1 schematically shows an example of a preferred embodiment of the respiratory gas supply device of the present invention.

[Explanation of symbols]

 1: Oxygen concentrator 2: Cushion tank 3: Automatic opening / closing valve 4: Cushion tank 5: Conduit means 7: Nasal cannula 9: Respiratory phase detection means 10: Control means

Claims (1)

(57) [Claims] 1. Respiratory gas generating means, conduit means having one end communicating with the generating means, open-type supply means for the respiratory gas at the other end, and automatic opening and closing valve means on the way, Respiratory phase detecting means having a function of detecting at least a part of the predetermined phase in the above, and control means for controlling the opening and closing of the automatic opening and closing valve means based on the detection result of the detecting means In the supply device, a respiratory gas supply device provided with a cushion tank upstream and / or downstream of the automatic opening / closing valve means.