JP2005279296A - Oxygen concentrator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen concentrator usable when a patient is at home and/or out (including moving in a vehicle or the like). <P>SOLUTION: This oxygen concentrator is provided with a compression means for compressing air taken in from an air intake port via an inspiration filter, an adsorption means adsorbing predetermined components other than the oxygen in the compressed air in an adsorption cylinder and removing them from the compressed air, and a product tank for accumulating the enriched oxygen formed by removing the predetermined components; and is provided with an open valve in an exhaust channel for exhausting the adsorbed components other than the oxygen. This oxygen concentrator is characterized in that the inspiration filter has a noise reduction structure and the degree of vacuum in the channel internal pressure can be regulated by actuating the open valve. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an oxygen concentrator, and more particularly to a portable oxygen concentrator for improving patient convenience.

Conventionally, oxygen concentrators used in oxygen inhalation methods that are effective for treating patients with respiratory diseases such as chronic bronchitis use zeolite as an adsorbent that permeates oxygen in the air and selectively adsorbs nitrogen. The adsorption method used is widely used.

However, this type of oxygen concentrator is normally used by a home patient in a home and has a total weight of about 40 to 50 kgw, and is not portable. When the patient goes out, it is necessary to supply concentrated oxygen from the oxygen cylinder while pushing the cart equipped with the oxygen cylinder, which significantly impairs the patient's QOL. In addition, a portable oxygen concentrator capable of using a battery has been proposed (Patent Document 1), but the total weight is 10 kgw, which can be driven only for about 30 minutes, and is not practical. .
JP 2002-45424 A

An object of the present invention to solve the above-mentioned problems is to provide an oxygen concentrator that can be used even when a patient is at home and / or going out (including when moving in a vehicle).

In order to solve the above problems, an oxygen concentrator of the present invention comprises a compression means for compressing air taken in from an air intake through an intake filter, and a predetermined component other than oxygen in the compressed air. Adsorption means for removing from the air compressed by adsorption in the adsorption cylinder, a product tank for accumulating concentrated oxygen from which predetermined components have been removed, and for discharging components other than the adsorbed oxygen An oxygen concentrating device having an open valve in the exhaust flow path of the gas generator, wherein the intake filter has a muffler structure, and the degree of vacuum of the pressure in the flow path can be adjusted by operating the open valve Concentrator.

According to the oxygen concentrator of the present invention, it is small in size, light in weight and low in power consumption, can be portable even when the patient is out, etc., is reduced in noise, and is useful for patient QOL.

FIG. 1 is a block diagram showing an example of the configuration of a portable oxygen concentrator that is an oxygen concentrator corresponding to an embodiment of the present invention. The thick lines and arrows indicate the flow direction of the piping channel (conduit) and air (concentrated oxygen). As shown in FIG. 1, air taken into the oxygen concentrator 1 from the air intake 100 is taken in from the air intake 100, and after dust is removed by the filter 101 and the intake filter 102 that also serves as a muffler buffer. Compressed by a compressor (compression means) 105. The compressor (compression means) 105 is cooled by a cooling fan 104.

The compressed air is filled with an adsorbent via a three-way switching valve (pilot type three-way electromagnetic valve) 107 as a channel switching means for switching the piping channel, and two adsorption cylinders 108a, which are arranged in parallel, It is sent to one of 108b.

Gas separation is performed in the adsorption cylinders 108a and 108b, and the produced oxygen-enriched gas is temporarily sent to the product tank 111, and then further passed through a pressure regulator 112 and a flow rate regulator (flow rate setting unit) 115. Thus, the flow rate based on the pressure and the flow rate is controlled (at this time, the oxygen concentration is detected by the oxygen concentration sensor 114 connected to the pressure regulator 112), and passes through a breathing tuner (demand valve) 116, and then the oxygen concentrator. One oxygen supply outlet (one-touch oxygen outlet) 117 is configured to supply oxygen concentrated to about 90% of the maximum flow rate of 2 L / min to a patient via a nasal cannula (not shown). Further, in order to exhaust (exhaust) components other than the adsorbed oxygen, an exhaust passage is formed by the decompression means VP, the exhaust muffler 120, and the exhaust port 121 of the compressor 105. An open valve (vacuum break valve) 118 is provided in the exhaust passage. The oxygen concentrator 1 is normally driven by a commercial power source via an AC power connector 130 connected to an AC power source and a switching power source unit 125. The battery (rechargeable battery) 127 is used when going out. Reference numeral 126 denotes a power switch, and 128 denotes a display unit. The display unit 128 is formed of an LED or the like, and is in an operating state (lights up or blinks in green during normal operation / lights up or blinks in red at the time of abnormality or stop), and oxygen concentration (lights up or blinks in green at a predetermined concentration). Lights up or blinks in red when outside the specified concentration range), breathing synchronization monitor display (lights up or blinks in green during breathing synchronization control), battery remaining amount display (multiple colors from green to red, for example, 6 colors), etc. It is designed to display.

This oxygen concentrating device 1 realizes miniaturization, weight reduction, and low power consumption for extending the driving time when the battery is driven and for improving convenience when the patient is out / in the room. Various ideas have been made for this purpose, and will be described in detail below.

<Intake filter>
The intake filter 102 has a silencing structure, and has an integral structure that also has a filter inside. The volume is about 200 cc, and the weight is about 120 gw.

<Compressor>
The compressor 105 has a total weight of about 1 kgw, and is driven and controlled by a control unit (CPU) 124, a motor control unit 123, and a variable speed controller 123a. The compressor 105 has both a pressurizing function (pressurizing means: P) and a decompressing function (depressurizing means: VP). The rotation speed of the compressor 105 is controlled according to the oxygen flow rate taken out, and the speed is controlled between 500 rpm and 3000 rpm. The operating life when rotating at the optimum speed (about 1700 rpm) is about 15000 hours. The operating temperature surrounding the compressor / motor system is preferably between 0 ° C and 40 ° C. The voltage for the compressor 105 is preferably 12 V or 24 V DC (power source obtained from an adapter such as an automobile), and the power consumption is controlled at about 45 to 80 W. In order to cool the compressor 105 and, if possible, the entire oxygen concentrator 1, at least two cooling fans (cooling means) 104 such as a shaft-mounted fan or a blower with power consumption of about 2.7 W are attached to the compressor 105. Can be. The maximum noise pressure level of the oxygen concentrator 1 is 35 dBA or less at the maximum rotation speed to be controlled, and 33 dBA when the concentrated oxygen flow rate is 1 L / min or less. The compressor 105 is adapted to compress air to 100 kPa, preferably 60 kPa or less.

The compressor 105 can be operated at various speeds, provides the necessary vacuum / pressure levels and flow rates, produces little noise and vibration, generates little heat, is small and light, and has little power Is preferable. A variable speed controller (variable speed control means) 123a is provided in order to reduce power consumption required for the compressor 105 with respect to a power source such as a rechargeable battery 127 or another commercial power source. By providing the variable speed controller 123a, the speed of the compressor 105 can be changed based on the activity level of the patient and the environmental conditions. For example, the variable speed controller 123a reduces the drive (rotation) speed of the compressor 105 when it is determined that the patient's oxygen demand is relatively low, such as when the patient is sitting, sleeping, or in a low place. Speed can be increased when it is determined that the patient's oxygen demand is relatively high or increased, such as when standing, active, or at high altitude. This reduces the power consumption of the oxygen concentrator 1 as a whole, extends the life of the rechargeable battery 127 when driven by the rechargeable battery 127, reduces the weight and size of the rechargeable battery 127, and reduces the degree of wear of the compressor 105. To extend the life and improve the reliability.

<3-way switching valve / control>
In the conventional apparatus, an electromagnetic valve generally called a direct acting type is used, and the operation of the valve is based on electric force. This type of solenoid valve has a problem of high power consumption because the main valve is operated only by electric power. The pilot-type three-way switching valve 107 employed in the oxygen concentrator 1 can be operated using a small amount of power consumption and air pressure from the compressor, so that the power is greatly reduced (from 8 W to 0.5 W). Reduced). In FIG. 2, 107a1 and 107b1 are main valves (main solenoid valves), and 107a2 and 107b2 are pilot valves (pilot solenoid valves). Since the pilot valves 107a2 and 107b2 open and close the main valves 107a1 and 107b1 by a slight pressure from the compressor 105, power consumption can be reduced compared to the direct acting type. The same reference numerals as those in FIG. 1 indicate the same components. 107a3 and 107b3 are check valves. The control sequence is different from the conventional method, as shown in FIG. 3, first, the compressor 105 is operated for a predetermined time (0.5 seconds in FIG. 3) (compressor starting process), and then the three-way switching valve 107 is operated. The pilot valve 107a2 is controlled to operate (open operation) (the operation state is indicated by an arrow). By controlling in this way, the pilot valve can use the air pressure, and the main valve can be operated with a small amount of electric power. When the main valve is opened, the compressed air flows into the adsorption cylinder 108a (adsorption cylinder A) and becomes an adsorption process in which gas adsorption is performed. The pressure equalizing valve is opened for a predetermined second (at this time, the first half of the opened state is the cleaning step of the suction cylinder 108b (suction cylinder B)). When the cleaning process of the adsorption cylinder 108b is completed, the main valve 107b1 of the three-way switching valve 107 is controlled to operate (open operation). In the latter half of the opening operation state of the pressure equalizing valve, the main valves 107a1 and 107b1 of the three-way switching valve 107 are in the opening operation state, which is a so-called pressure equalizing process. Thereafter, the adsorption process, the washing process, and the pressure equalization process are repeated in the same sequence. Note that the compressor 105 is in an operating state in all the above steps (start-up step, adsorption step, cleaning step, pressure equalization step). Here, the process starting from the adsorption process of the adsorption cylinder 108a has been described. However, the process may start from the adsorption process of the adsorption cylinder 108b first. In addition, an open valve 118 is connected (communication) to the exhaust flow path side of the three-way switching valve 107, and in synchronization with the pressure equalization process, the control unit 124 operates the open valve 118 in an open state so that the compressor 105 has a high vacuum. The state is reduced (the degree of vacuum can be adjusted), vibration is prevented, and noise is reduced.

<Open valve>
The form of the compressor 105 employed in the oxygen concentrator 1 has both a pressurizing function (pressurizing means: P) and a decompressing function (depressurizing means: VP). By adopting this type of compressor, an oxygen recovery rate can be increased and the concentration unit can be made smaller than an oxygen concentrator constituted only by pressurizing means. However, the integrated compressor has a problem that the vibration is larger than that of the compressor dedicated to pressurization or the compressor dedicated to vacuum. In particular, in the oxygen concentration process, the vibration becomes intense during the pressure equalization step. During the pressure equalization process, the flow path of the three-way switching valve 107 is in communication between the pressure function side and the suction cylinder side, and the pressure reducing function side is shut off, so that an extremely high vacuum state exists between the three-way switching valve and the pressure reducing means. It is because it becomes. In order to solve this problem, first, an open valve 118 communicating with the outside air is provided in the flow path, and further, the open valve 118 is operated to be opened by the control unit 124 in synchronization with the pressure equalization step. Thus, outside air enters the flow path, and the flow path is closer to the atmospheric pressure. Due to this action, the compressor 105 is in a state close to a no-load state, so that the occurrence of vibrations can be prevented, and it also contributes to noise reduction and low power consumption.

<Adsorption cylinder>
Adsorption cylinders 108a and 108b as gas separation means have at least two adsorption cylinders arranged in parallel, and the adsorbent to be filled has a granule measurement value of less than 1 mm, and SiO ₂ / Al ₂ X-type zeolite having an O ₃ ratio of 2.0 to 3.0 and at least 88% of Al ₂ O ₃ tetrahedral units fused with lithium cations are preferred.

<Pressure regulator>
In the product tank 111 of FIG. 1, since the pressure fluctuates in synchronization with the pressure in the adsorption cylinder, the pressure regulator 112 includes a relief valve (open valve) 112a and a pressure reducing valve 112c to depressurize concentrated oxygen, It functions to be almost constant pressure. Furthermore, as shown in FIG. 4, it has a relief function (relief valve) 112a and a filter function (filter 112b) when the oxygen discharge pressure (secondary pressure) rises abnormally. Compared with the type in which parts are installed, the workability such as small size, light weight and maintenance can be improved. A flow rate setting device is installed on the downstream side of the pressure regulator. This flow rate setting device restricts the flow rate with an orifice, and the hole diameter is 120 to 150 at the minimum although it depends on the set discharge pressure. A pore diameter (average pore diameter) of about a micron (micrometer) is set. Therefore, it is preferable that the filter used here has a pore diameter (average pore diameter) of 100 microns or less (micrometer) or less in terms of obtaining a stable flow rate. The relief function is intended to protect the fine pressure sensor used when detecting intake air.

<Respirator (demand valve) / Control>
When the control unit 124 determines that the oxygen flow rate in the flow rate setting device 115 is set to a predetermined flow rate (for example, 1.25 L / min or more) and is driven by the battery 127, the control unit 124 suppresses the power consumption of the battery 127. By the sequence control shown in FIG. 5, the control unit 124 and the respiration synchronization control unit (demand control unit) 122 substantially increase the oxygen generation capacity of 1 L / min and the respiration synchronization control (demand control) to substantially 2 L / min of oxygen. Applicable up to flow rate. For this reason, the power consumption is about 50 W at the flow rate of concentrated oxygen of 2 L / min. The opening operation of the main valves 107a1 and 107b1 of the three-way switching valve 107 and the opening operation of the release valve 118 and the pressure equalization valve in the adsorption process, the washing process, and the pressure equalization process are as indicated by arrows. At this time, the compressor 105 and the breathing synchronization device 116 are in a continuous operation state. The pressure fluctuation in the product tank 111 is shown below. In addition, such an oxygen concentration process is an example, and is not limited to this example.

<Power supply>
In order to function properly as a portable system 100 as shown in FIG. 6 with a body weight of the oxygen concentrator 1 that is 10 kgw or less, the system 100 is supplied with power from an appropriate rechargeable power source. There must be. Conventionally, the battery used in such a system has an unclear remaining capacity, and it has been difficult to predict the remaining battery capacity due to a decrease in capacity due to repeated use. The power source of the oxygen concentrator 1 can be charged / discharged about several hundred times, and has a management function such as the remaining battery level, the number of charge / discharge cycles used, the degree of deterioration, and the output voltage. The charging capacity and the number of times of charging / discharging are displayed on the display unit 128 (see FIG. 1) or can be read by an external monitor device via the communication connector 129 (see FIG. 1). With this function, it is possible to manage the remaining amount as the actual value of the battery according to the degree of deterioration, not the uncertain remaining amount as in the conventional battery. In addition, the oxygen concentrator 1 is preferably detachably provided via a connector 127a (see FIG. 1), and preferably has a structure in which it is laminated in a lithium ion form, and an output voltage of 21.0 to 29.0V. A battery 127. In addition, the weight is about 1.5 kgw, and when performing respiration synchronization control, an operation for a maximum of 3 hours is possible when the concentrated oxygen flow rate is a maximum of 2 L / min. The system 100 can also be supplied from other portable energy sources besides the lithium ion battery. For example, rechargeable or replaceable fuel cells can be used. Although the system is generally described as being powered by a single rechargeable battery 127, the system 100 can also be powered by multiple batteries. Thus, “battery” as used herein includes one or more batteries. Further, the rechargeable battery 127 may include one or more internal and / or external batteries. The battery 127 or battery module including the battery 127 is preferably removable from the system 100. The system 100 can use a standard internal battery, a low cost battery, an extended working internal battery, a secondary battery external to the clip mounting module. The system 100 can include a built-in adapter that includes a battery charger 143 that can be connected to a charging connector 131 and one or more plugs (not shown) that are connected to the system 100 by a DC power source ( For example, power is supplied from a car cigarette lighter adapter) and / or from an AC power source (eg, AC wall socket of a commercial power source in a home or office), while the battery 127 is charged from the DC or AC power source. It is configured as follows. The adapter or charger 143 can also be a separate accessory. For example, the adapter may be a separate cigarette writer adapter 144 that drives the system 100 and / or charges the battery 127 in an automobile. A separate AC adapter may be used to convert AC from the output to DC for use in system 100 and / or to charge battery 127. Other examples of adapters include adapters for use with wheelchair batteries or other carts. The gantry 142 on which the system 100 is mounted can be considered as a part of the system 100 or an accessory independent of the system 100. The cradle 142 may include one or more additional charging attachments (not shown) connected to the charger 143 to charge a spare battery pack (not shown). Having the charging attachment and one or more additional battery packs allows the patient to go out for longer periods of time and improve their QOL. The patient can always have an additional, freshly charged battery 127. The gantry 142 and / or the system 100 may include humidification means 140 for adding moisture to the concentrated oxygen flow in the system 100 via suitable connections. Further, the gantry 142 and / or the system 100 may be a cart (two-wheel or four-wheel cart) having wheels, and a handcart 142a provided with a stopper 145, a retractable / extendable handle 146, and the like. The system 100 may include a soundproof box 148 that covers the oxygen concentrator 1 and the charger 143 for soundproofing at bedtime.

<Respiration synchronization control>
When the entire oxygen concentrator 1 is driven by the rechargeable battery 127, in order for the patient to use the concentrated oxygen more efficiently, a control synchronized with breathing is performed. During normal breathing, the patient spends about 1/3 of the inspiration / expiration cycle time on inspiration and the remaining 2/3 on exhalation. The enriched oxygen generated during exhalation is unnecessary for the patient, and as a result, the additional battery power that efficiently provides this surplus enriched oxygen flow is wasted. By supplying the concentrated oxygen produced during exhalation during inspiration, if the inspiration / expiration cycle is 1 (inspiration): 2 (exhalation), then triple inspiration It is possible to supply up to a flow rate. Thus, by performing respiratory synchronization control, it is possible to reduce the size and power consumption of the apparatus. The opening / closing control of the breathing tuner 116 is performed over the entire period as shown in FIG. 5 (the compressor 105 also operates over the entire period). In FIG. 5, the arrows indicate the periods of the opening operation of the main valves 107 a 1 and 107 b 1 of the three-way switching valve 107 and the opening operation of the opening valve 118 and the pressure equalizing valve.

<Various sensors>
The oxygen concentrator 1 is equipped with an oxygen sensor 114 as standard, but includes various sensors such as an acceleration sensor 125, a GPS (global position sensor) 134, a shock sensor 132, a pulse sensor, a blood pressure sensor, and a blood oxygen saturation sensor. Etc. can be attached as an option. A galvanic cell type, an ultrasonic type, a zirconia type sensor or the like can be used as the oxygen sensor to be employed, but a zirconia type oxygen sensor is preferable from the viewpoint of size and measurement accuracy. However, the method called the zirconia method has a problem that power consumption is high because the zirconia polymer film must be heated by a heater. In order to reduce power consumption, especially during battery operation, it is effective to minimize power consumption by operating intermittently (heating the heater intermittently) instead of continuous measurement (heating the heater continuously). Yes, when the measured value by the oxygen sensor 114 is out of a predetermined range, the measurement reliability can be improved by switching to the continuous measurement for a predetermined period. In addition, when it is confirmed that it is within the predetermined range by continuous measurement for a predetermined period, the intermittent measurement may be automatically returned.

It is a figure which shows an example of a structure of the oxygen concentrator corresponding to this invention. It is a figure which shows the solenoid valve of the oxygen concentrator corresponding to this invention. It is a figure which shows the control sequence in the oxygen concentration apparatus corresponding to this invention. It is a figure which shows the pressure regulator in the oxygen concentration apparatus corresponding to this invention. It is a figure which shows the driving | running control sequence at the time of the breathing tuner operation | movement in the oxygen concentration apparatus corresponding to this invention. It is a figure which shows the whole system containing the oxygen concentrator corresponding to this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Oxygen concentrator, 101 ... Filter, 102 ... Intake filter, 105 ... Compressor, 107 ... Solenoid valve, 108a, b ... Adsorption cylinder, 112 ... Pressure regulator 116 ... Respirator, 114 ... Oxygen sensor, 127 ... Battery, 100 ... Overall system

Claims (1)

Compressing means for compressing air taken in from an air intake through an intake filter, and a predetermined component other than oxygen in the compressed air is adsorbed in an adsorption cylinder, and from the compressed air Oxygen concentration provided with an adsorbing means for removing, a product tank for accumulating concentrated oxygen from which the predetermined component has been removed, and an open valve in an exhaust passage for discharging components other than the adsorbed oxygen A device,
The intake filter has a silence structure,
An oxygen concentrating device, wherein the degree of vacuum of the pressure in the flow path can be adjusted by operating the release valve.

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