JPH01274771A - Medical oxygen concentrating device - Google Patents

Abstract

PURPOSE:To produce concentrated oxygen gas efficiently and stably, and thereby improve inhaling efficiency by providing a compressor connected with the induction port of an absorption floor via No.1 solenoid valve, No.2 solenoid valve releasing the induction port selectively to atmosphere and a sensor detecting the phase of inhalation of a human. CONSTITUTION:The output of a sensor 11 is supplied to a controller 13 via an amplifier 12, and when the start of the inhaling phase of a patient 10 is detected, No.1 solenoid valve 2 during the induction period of pressurized air is opened, and No.2 solenoid valve 5 for the same period is closed so that compressed air from a compressor 4 is supplied into an absorption floor 1 via No.1 solenoid valve 2 so as to let concentrated oxygen gas produced be stored in a produced gas surging tank 7 through an exhaust port 16 of the absorption floor 1. Then, while a device is inoperative, No.1 and No.2 solenoid valves are closed, the pressure of concentrated oxygen gas at the surge tank 7 exceeds the push-through pressure of a check valve 8 so that the oxygen is forwarded to the patient 10 through a nose cannula 9 in such a way as to meet his inhaling phase. Following which, while pressure is released to atmosphere, No.2 solenoid valve 5 is opened, the induction port 1a of the absorption floor 1 is released to atmosphere via No.2 solenoid valve 5 and a silencer 6.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a pressure fluctuation adsorption type medical oxygen concentrator.

(Prior Art) Various pressure fluctuation adsorption type medical oxygen concentrators have been proposed in the past. For example, in Japanese Patent Publication No. 57-5571, two adsorption beds are used, and one of the adsorption beds is A portion of the oxygen-enriched gas produced by the adsorption bed during an adsorption cycle is used to purge the other adsorption bed, such that the operating cycles of each adsorption bed are alternated. ing. According to this oxygen concentrator.

Even though each adsorption bed has a relatively small volume, it is advantageous that oxygen-enriched gas of a desired concentration can be produced because they are purged from each other.

In addition, in Japanese Patent Publication No. 57-52090, relatively small adsorbent particles of 40 to 80 mesh are packed into an adsorption bed with a certain relationship between diameter and length, which creates flow resistance during the operation of each process. After introducing compressed air into the adsorption bed for a short period of time, the inlet is opened to the atmosphere to reduce the pressure after a predetermined stop time has elapsed, thereby obtaining oxygen fiwJ gas during the compressed air introduction period and the stop period. discloses a medical oxygen concentrator in which an adsorbent is purged by generating a reverse flow in an adsorption bed due to a pressure difference during an open atmosphere period. According to this medical oxygen concentrator, one cycle of operation of the adsorption bed, which consists of a compressed air introduction period, a stop period, and an atmosphere opening period, can be made extremely short at 3 to 30 seconds. The production amount of generated gas per weight can be relatively high,
This has the advantage that the entire device can be made smaller and lighter. Furthermore, in Japanese Patent Publication No. 57-44361, a plurality of adsorption beds are used, and one cycle of operation of each adsorption bed is divided into a compressed air introduction period,
This operation cycle is set at different timings between the adsorption beds as a shutdown period, an atmosphere release period, and a product repressurization period, so that a portion of the product gas produced during the compressed air introduction period of a certain adsorption bed is transferred to the atmosphere. A medical oxygen concentrator is disclosed for use as a purge gas in other adsorption beds during open periods and as a product repressurization gas in other adsorption beds during product repressurization periods.

On the other hand, using a medical oxygen concentrator as described above, the concentrated oxygen gas generated by the device is supplied to patients with respiratory or circulatory system diseases through a solenoid valve or the like in synchronization with their breathing. Various breathing synchronized oxygen supply devices have been proposed. For example, Japanese Patent Publication No. 62-54023 discloses that oxygen-enriched gas is supplied during each inspiratory phase via a solenoid valve in response to a timing signal for transitioning from the expiratory phase to the inspiratory phase based on an electrical signal generated from the respiratory airflow. An oxygen gas supply device is disclosed.

(Problem to be Solved by the Invention) However, the conventional medical oxygen concentrator described above is configured to operate independently, regardless of the patient's breathing movement, and therefore, for example, it is difficult to direct the generated gas to the patient. When the gas is not needed, the gas cannot be used to purge the adsorption bed, and when a large amount of produced gas is used for patients, a sufficient amount of gas cannot be used to purge the adsorption bed at the same time. There is a problem that there is a problem that efficiency improvement occurs over time. In addition, one possible way to solve this problem is to increase the capacity of the surge tank that stores the oxygen-enriched gas generated in the adsorption bed, but this would make the entire device large and expensive. There is a problem.

This invention was made by focusing on these conventional problems, and provides a medical oxygen concentrator that is appropriately configured so that it can efficiently and consistently produce oxygen-concentrated gas and the entire device can be made compact. The purpose is to provide

(Means and effects for solving the problem) In order to achieve the above object, in this invention, an adsorption bed, a compressor connected to the inlet of the adsorption bed via a first electromagnetic valve, and the inlet are selected. a second NEn valve that is open to the atmosphere;
a sensor that detects the phase of a person's breathing; and based on the output of this sensor, compressed air from the compressor is introduced into the adsorption bed in synchronization with the intake in each breathing cycle, and then the introduction of the compressed air is and control means for controlling the first and second solenoid valves so as to open the inlet of the adsorption bed to the atmosphere after the adsorption bed is stopped, during a period of introduction of compressed air to the adsorption bed and a subsequent stop period. The adsorption bed is configured to produce oxygen-enriched gas from the adsorption bed and to purge the adsorption bed during a subsequent open-to-air period.

(Embodiment) FIG. 1 shows a first embodiment of the present invention. In this embodiment, one adsorption bed 1 is used, and its inlet 1a is connected to a compressor 4 via a first solenoid valve 2 and an air tank 3, and is connected to a compressor 4 via a second solenoid valve 5 and a silencer 6. Allow it to be exposed to the atmosphere. The outlet 1b of the adsorption bed 1 is connected via a product gas surge tank 7 and a check valve 8 to a nasal cannula 9 through which oxygen enriched gas is supplied to the patient 10. Further, a sensor 11 for detecting exhalation and inhalation of the patient 10 is provided, and based on the output of this sensor 11, the first and second electromagnetic valves 2
．． 5 is controlled. The sensor 11 may be a thermocouple, a thermistor, a pyroelectric sensor, etc. that detects the temperature difference between exhaled air and inhaled air, or a humidity sensor that detects changes in humidity or a pressure sensor that detects changes in pressure. Alternatively, it can be configured to detect exhalation and inspiration from electromyogram signals of abdominal and chest muscles using an electromyogram.

In this embodiment, the first solenoid valve 2 is opened and the second solenoid valve 5 is opened.
is closed and compressed air is introduced into the adsorption bed 1 during the compressed air introduction period. A stop period in which the second solenoid valves 2 and 5 are both closed and the introduction of compressed air is stopped, and the first solenoid valve 2
is closed, and the second solenoid valve 5 is opened to open the inlet 1a of the adsorption bed 1.
The period of opening to the atmosphere through the silencer 6 constitutes one operation cycle of the adsorption bed 1, and this operation cycle is performed in synchronization with each respiratory cycle of the patient 10 based on the output of the sensor 11. Here, since the number of human breaths is approximately 15 times per minute, that is, one breathing cycle is approximately 4 seconds, the compressed air introduction period is set to 0.4 seconds from the start of exhalation, and the stop period is the same as the compressed air introduction period. It is 1.2 seconds from the end, and the atmosphere release period is the time from the end of the stop period to the start of inhalation in the next breathing cycle.

The detailed configuration of each part in this embodiment will be described below.

For example, a patient with chronic respiratory failure typically inhales a constant flow of oxygen-enriched gas through a nasal cannula of ~2 IPZ minutes! There are many people with / minutes. Therefore, in the above configuration,
If we try to generate a constant flow of 21/min, one respiratory cycle is about 4 seconds, and the time ratio between the expiratory period and the inspiratory period is approximately 2:1, so about 44 cc is generated during the inspiratory period of one respiratory cycle. It is necessary to generate oxygen-enriched gas.

Therefore, in this example, the capacity of the adsorption bed 1 is set to about 1300.
Approximately 900 g of an adsorbent consisting of 30 to 90 mesh crystalline zeolite molecular sieve is filled into the adsorption bed 1 as cc, and the capacity of the air tank 3 is set to approximately 1000 cc, and the compressor 4 is used for one breathing cycle (approximately 4 seconds).
700-1000d of raw air at 3.5kg/cm2
- The compressed air is compressed to a gauge and the compressed air is delivered into the adsorption bed 1 during a compressed air introduction period of 0.4 seconds. In addition, in order to improve the recovery rate and utilization rate of the oxygen gas produced in the adsorption bed 1, the oxygen-enriched gas produced in the adsorption bed 1 is stored in the surge tank 7 for produced gas, and the surge tank 7 is Oxygen-enriched gas is supplied to the patient 10 via the check valve 8 at the beginning of the patient's 10 inspiratory phase, and the gas remaining in the surge tank 7 is then flowed back into the adsorption bed 1 as purge gas. Thus, check valve 8
The push-through pressure at is adjusted so as to obtain an effective balance between the amount of oxygen-enriched gas delivered to the patient 10 and the amount of gas for purge regeneration. That is, when this push-through pressure is lowered, the amount of gas delivered to the patient 10 increases, the amount of purge gas decreases, and the concentration of the oxygen-enriched gas obtained decreases. On the other hand, when the push-through pressure is increased, the amount of gas obtained for the patient 10 decreases, the amount of purge gas increases, and the gas concentration increases. Note that the recovery rate of the produced oxygen gas in this example is about 22%.

Next, the operation of this embodiment will be explained.

The output of the sensor 11 is fed via an amplifier 12 to a control unit 13 in which the start of an inspiratory phase in a sequential respiratory cycle of the patient 10 is detected based on the output of the sensor 11. When the control unit 13 detects the start of the inspiratory phase in each breathing cycle, the control unit 13
2 (compressed air introduction period), the first solenoid valve 2 is opened, and the second
After closing the first and second solenoid valves 2.5 for 1.2 seconds (stop period), the start of the inspiratory phase of the next breathing cycle is detected. Until (
Atmospheric release period) The first solenoid valve 2 is closed and the second solenoid valve 5 is opened.

On the other hand, the air compressed by the compressor 4 is stored in the air tank 3, and during the compressed air introduction period, it is supplied from the introduction port 1a into the adsorption bed 1 through the first electromagnetic valve 2, and the oxygen concentration produced thereby. The gas is supplied from the outlet 1b of the adsorption bed 1 to the generated gas surge tank 7 and stored therein. Oxygen-enriched gas accumulates in this surge tank 7 between the compressed air introduction period and the subsequent stop period, and its pressure rapidly increases to exceed the push-through pressure of the check valve 8 and is passed through the nasal cannula 9 to the patient. 10 in its inspiratory phase. After that, the second solenoid valve 5 is opened during the atmosphere opening period, and the inlet 1 of the adsorption bed 1 is opened.
a is opened to the atmosphere via the second solenoid valve 5 and silencer 6, the pressure drop inside the adsorption bed 1 caused by ventilation resistance due to the adsorbent is discharged from the inlet port 1a by opening to the atmosphere. Proceed in the direction of exit 1b. As a result, the production of oxygen gas in the adsorption bed 1 is stopped, and the pressure of the oxygen-enriched gas in the generated gas surge tank 7, which had been flowing out to the patient 10, also decreases, causing push-through pressure. When the amount is below, the delivery to the side 10 is stopped, and the oxygen-enriched gas flows back into the adsorption bed 1 as a purge gas from the outlet 1b of the adsorption bed 1. Therefore, for this person with regurgitation, one breathing cycle takes about 4 seconds, and 1.6 seconds have passed since the start of inspiration, so the time ratio between the inspiratory period and expiratory period in one breathing cycle is approximately 1:2. Taking this into consideration, it will be performed during the exhalation period of each breathing cycle.

FIG. 2 shows a second embodiment of the invention. In this embodiment, a solenoid valve 14 is provided in place of the check valve 8 of the first embodiment, and the solenoid valve 14 is controlled by the control unit 13 in synchronization with the start of inhalation in each breathing cycle based on the output of the sensor 1. By opening it and closing it after the adsorption bed has stopped, the amount of oxygen-enriched gas delivered to the patient 10 and the amount of purge gas flowing back into the adsorption bed 1 can be adjusted depending on the opening time. The other configurations are the same as in the first embodiment.

Note that this invention is not limited only to the embodiments described above, and numerous modifications and changes are possible. For example, the compressed air introduction period and the stop period are 0 and 4 as described above.
For example, the controller 13 detects the time of successive breathing cycles based on the output of the sensor 11, and the time of the next breathing cycle is determined based on the output of the sensor 11. It can also be predicted and automatically adjusted accordingly. In addition, a plurality of adsorption beds are used, each inlet of which is connected to a common compressor through a first solenoid valve, and can be opened to the atmosphere through a second solenoid valve. By connecting the outlet to a common product gas surge tank and sequentially selecting and operating these multiple adsorbent beds in synchronization with the breathing cycle, each adsorbent bed can be used for regeneration of the adsorbent. It is also possible to make the time longer. Furthermore,
In the embodiment described above, the generated gas surge tank 7, the check valve 8, and the solenoid valve 14 are used, but these are omitted and the nasal cannula 9 is connected from the discharge port 1b of the adsorption bed 1.
Oxygen-enriched gas can also be supplied directly to the patient 10 via the oxygen-enriched gas. Furthermore, in the above-described embodiment, compressed air from the compressor 4 is introduced into the adsorption bed 1 in synchronization with the start of intake, but this may occur before the generated oxygen-enriched gas is sent into the nasal cavity of the person. In order to reduce the time delay, the control unit 13 discriminates the respiratory airflow stop period that generally exists slightly between a person's exhalation and inhalation, based on the output of the sensor 11, so that the respiratory airflow starts before the start of inhalation. The introduction of compressed air may be controlled to start at the start of stopping. Further, based on the output of the sensor 11, a timer generates a delay signal starting from the start of stopping the respiratory airflow during the respiratory airflow stopping period from the end of the exhalation phase to the point of transition to the inhalation phase. The introduction of compressed air may be started at any fixed time during the respiratory airflow stop period to synchronize with respiration so as to reduce the time delay of air being sent into the nasal cavity.

(Effects of the Invention) As described above, according to the present invention, oxygen-enriched gas is generated in synchronization with human intake, and the adsorption bed is purged and regenerated during the exhalation period, that is, the period when oxygen-enriched gas is not required. As a result, oxygen-enriched gas can be efficiently and always stably generated, improving the efficiency of human inhalation and use, and making the entire device smaller. In addition, in the above-described embodiment, the compressor only needs to have the ability to compress approximately 1000 d of air to 3.5 kg/cm'' gauge during one breathing cycle, so it is not necessary to use the conventional constant-flow field type oxygen concentrator. Its capacity is 173 to 1/6 compared to the compressor used.
It can be done. Therefore, the entire device can be made inexpensive.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a first embodiment of the present invention, and Fig. 2 is the same (a diagram showing a second embodiment). ■... Adsorption bed 1a... Inlet port 1b...
・Discharge port 2...First solenoid valve 3...Air tank 4...Compressor 5...Second solenoid valve 6...Silencer 7...Surge tank for generated gas 8... Check valve 9... Nasal cannula IO
...Patient 11...Sensor 12...
Amplifier 13...Control unit 14...Solenoid valve Fig. 1 Fig. 2/A

Claims (1)

[Claims] 1. An adsorption bed, a compressor connected to an inlet of the adsorption bed via a first solenoid valve, and a second solenoid valve that selectively opens the inlet to the atmosphere; a sensor for detecting the phase of a person's breathing, and based on the output of this sensor, introduces compressed air from the compressor into the adsorption bed in synchronization with inspiration in each breathing cycle, and then stops introducing the compressed air; After that, the inlet of the adsorption bed is opened to the atmosphere,
control means for controlling the first and second electromagnetic valves, and producing oxygen-enriched gas from the adsorption bed during a period of introduction of compressed air to the adsorption bed and a subsequent stop period, and a subsequent period of opening to the atmosphere; A medical oxygen concentrator, characterized in that it is configured to purge the adsorption bed. 2. A check valve is connected to the discharge port of the adsorption bed via a generated gas surge tank, and the oxygen-enriched gas is taken out through this check valve, and the amount of taken-out gas and purge gas are controlled by the push-through pressure of the check valve. 2. The medical oxygen concentrator according to claim 1, wherein the medical oxygen concentrator is configured to be able to adjust the amount. 3. A solenoid valve is connected to the outlet of the adsorption bed via a generated gas surge tank, and the solenoid valve is opened in synchronization with the intake of each breathing cycle by the control unit based on the output of the sensor. 2. The medical device according to claim 1, wherein the oxygen enriched gas is taken out through the solenoid valve, and the amount of gas to be taken out and the amount of purge gas can be adjusted by controlling the opening time of the solenoid valve. Oxygen concentrator.