JP2804282B2 - Oxygen-enriched air supply device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxygen-enriched air supply device for supplying oxygen-enriched air to a human body, and more particularly to an oxygen-enriched air supply device adapted to the respiratory state of the human body. The present invention relates to an oxygen-enriched air supply device provided with a respiratory synchronization device for supplying air.

[Conventional technology]

It is often the case that oxygen-enriched air is supplied to a patient. As a device for this, as shown in FIG. 15, oxygen-enriched air from an oxygen cylinder or an oxygen concentrator 100 is supplied to a pressure regulating valve 101. For example, an oxygen-enriched air supply device that continuously supplies a constant amount directly into the oral cavity and the luminal cavity of a patient via the like is used.

[Problems to be solved by the invention]

However, in the conventional oxygen-enriched air supply device, since oxygen-enriched air is constantly supplied even during exhalation, excess oxygen-enriched air is discharged to the atmosphere, and about 50% of the air is discharged.
% Is wasted. Therefore, the device becomes unnecessarily large, and the power consumption is also required extra.
This is an obstacle in reducing costs.

In addition, even if the oxygen-enriched air is simply discharged in synchronization with the inspiration, the patient may be disturbed by whether or not the oxygen-enriched air is released, and breathing may be disturbed. Furthermore, at the end of inspiration, the oxygen-enriched air does not enter the lungs and becomes a dead volume, so that the oxygen-enriched air is wasted.

The present invention provides an oxygen-equipped oxygen-equipped oxygen-enriched air supply device that is capable of eliminating wasteful consumption of oxygen-enriched air and delivering a sense of security to a patient by sending oxygen-enriched air in conformity with the respiratory condition of the human body. It is an object to provide an enriched air supply device.

[Means for solving the problem]

Therefore, the present invention provides an oxygen-enriched air supply means for supplying oxygen-enriched air to a human body, an oxygen-enriched air supply path for sending oxygen-enriched air to a human body, and an oxygen-enriched air supply path. An ON-OFF switching valve 3 provided, a respiration sensor 5 attached to a human body for detecting a respiratory condition, and an ON-OFF switching valve 3 for opening and closing the ON-OFF switching valve 3 according to an output signal from the respiration sensor 5 In the oxygen-enriched air supply device having a controller 4, the controller 4 comprises:
The next respiratory cycle is predicted based on the output signal from the respiration sensor 5, the ON-OFF switching valve 3 is opened before inhalation starts, and the ON-OFF switching valve 3 is closed before inspiration starts. The structure of the device was adopted.

[Action]

An ON-OFF switching valve is provided on the oxygen-enriched air supply path for sending oxygen-enriched air to the human body, and a respiratory sensor for measuring the timing of inhalation and expiration of the human body is provided at a predetermined portion of the human body. The controller calculates the ON / OFF switching valve opening / closing timing according to the output signal from the sensor to predict the next respiratory cycle, and opens the ON-OFF switching valve before the start of inspiration and closes it before the start of expiration by this controller. .

With this configuration, it is possible to eliminate waste of oxygen-enriched air.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an oxygen-enriched air supply device for sending oxygen-enriched air to the human body. The oxygen-enriched air supply device has an oxygen enricher 1 as oxygen-enriched air supply means. The enricher 1 includes an oxygen-enriched film 1a and a vacuum pump 1b for sucking oxygen-enriched air. The oxygen-enriched air generated by the oxygen-enricher 1 is temporarily stored in the buffer tank 2, and the oxygen-enriched air is supplied from the buffer tank 2 to the oxygen-enriched air supply path 8 via the ON-OFF switching valve 3. It is delivered into the patient's mouth or nose.

Further, as the oxygen-enriched air supply means, an oxygen cylinder 7 or an adsorption-type oxygen concentrator 9 can be used instead of the oxygen enricher 1.

As shown in FIG. 2, the adsorption-type oxygen concentrator 9 has an air compressor 11, and the air pressurized and compressed by the air compressor 11 is sent to an adsorption cylinder 13a via a solenoid valve 12. . The adsorption cylinder 13a is filled with an adsorbent capable of adsorbing nitrogen or the like such as zeolite and generating oxygen-enriched air from air.

The air whose oxygen concentration is increased by the adsorption column 13a is stored in the oxygen-enriched air buffer tank 14, while the oxygen concentration is increased by the adsorption column 13b and sent to the adsorption column 13a again through the solenoid valve 12. Can be in this way,
By circulating the two adsorption cylinders 13a and 13b, it becomes possible to generate oxygen-enriched air from air.

Further, the exhaust gas discharged from the adsorption cylinder 13b is exhausted through the exhaust path e through the solenoid valve 12, and a pressure reducing silencer d is provided at the end of the exhaust path e so that the exhaust noise is reduced. Have been. At this time, the passage direction of the solenoid valve 12 is changed, so that the exhaust gas is not sent to the adsorption cylinder 13a.

The oxygen-enriched air stored in the oxygen-enriched air buffer tank 14 is sent to a pressure reducing valve 16 via a valve 15 and is reduced to a predetermined pressure.

Thereafter, the oxygen-enriched air decompressed to a predetermined pressure is sterilized by a bacterial filter 17, humidified by a humidifier 19 via a flow meter 18, and oxidized by an oxygen-enriched air supply passage 8.
(FIG. 1).

Further, the ON-OFF switching valve 3 forms a part of the respiratory synchronization device 6, and the respiration synchronization device 6 detects the timing when the patient inhales and exhales, in addition to the ON-OFF switching valve 3. It has a respiration sensor 5 and a controller 4 for controlling the opening / closing timing of the ON-OFF switching valve 3 according to a signal from the respiration sensor 5.

The respiration sensor 5 is attached to _two bands B ₁ and B ₂ and attached to the abdomen or chest of a human body as shown in FIGS. 3 to 6, and these bands B ₁ and B ₂ The end is fixed so as to be position-adjustable by an attached hook-and-loop fastener.

The respiration sensor 5 has a ceramic substrate 20;
A first conductive portion 21 of silver paste is formed on the substrate 20,
A U-shaped conductor 23 connected to a constant voltage DC power supply 22 is formed in parallel with the first conductive portion 21, and the conductor 23 is
And a second conductive portion 25. A brush 26 is provided between the resistor portion 24 and the first conductive portion 21 so as to be slidable left and right across the second conductive portion 25. The brush 26 is slid left and right. By moving it, the resistance value in the circuit is changed, and by taking out the voltage between the first conductive part 21 and the second conductive part 25, the respiratory state of the human body is detected.

That is, the brush 26 of the respiratory sensor 5 is connected via one end to the fitting 27 of the band B _2, the brush is guided by two parallel guide rods 28 and 28, the compression spring in the guide bar 28 The compression spring 29 expands in the chest and abdomen, that is, contracts in the inhalation process, and expands in the exhalation process to return the brush 26 to its original position.

In addition, such a sensor may use a rotary potentiometer, and as a respiration sensor, a temperature sensor is attached to a person's mouth or nasal cavity, and a temperature sensor or a pressure sensor that detects a temperature change during inhalation or expiration is used. There may be.

Next, the configuration of the controller 4 (FIG. 1) will be described.

The controller 4 includes a CPU 50 as shown in FIG.
The system bus 51 is connected to the CPU.The system bus 51 includes a ROM 52 storing a program for the CPU 50, a RAM 53 for temporarily storing various data for calculation, and A valve drive circuit 55 is connected via an input / output circuit 54. On the other hand, a detection signal from the respiration sensor 5 is input to the CPU 50 via the A / D converter 65 and the input / output circuit 56 via the system bus 51,
Further, a timing signal from a timing adjusting device 57 for setting the opening / closing timing of the ON / OFF switching valve 3 is input via an input / output circuit 58.

The CPU 50 includes a timer and a differentiation circuit (not shown), and the timer is configured by a program timer executed by a program process using an internal clock signal in the CPU. Note that a preset counter or the like provided separately using an internal clock signal may be used.

The differential operation by the differentiating circuit is executed by software processing based on a differential operation program stored in the ROM 52. These will be described later.

 Next, the operation principle will be described with reference to FIG.

The controller 4 samples the output signal of the sensor unit every 50 msec, stores the latest data DA (0) in the memory, and sequentially stores the data DA (0) in the previous memory in the memory.
It is slid and stored as (1), DA (2). Through the above processing, the memory always stores the latest three consecutive data DA (0), DA (1), and DA (2).

Next, the difference DS1 between the previous stored data and the data two times before, ie, DS1 = DA (1) −DA (2), and the difference DS0 between the latest stored data and the previous data, ie, DS0 = DA (0) −DA (1) is calculated, and when DS1 = 0 and DS0 <0 (for example, a1, a2,
a3, a4 points), change point from expiration to inspiration, DS1 = 0 and
When DS0> 0 (eg, b1, b2, b3, b4 points), it is regarded as a transition point from inspiration to expiration, and the inspiration counter and expiration counter are reset to 0, respectively, and the counter is counted up to the next transition point. Then, the expiration time and the inspiration time are measured. For example, in the case of counting the intake air, the intake air counter is counted up from point a2 to point b3 at regular time intervals.

The above operations are repeated sequentially, and the latest data BIT0, the previous data BIT1, and the data BI two times before are stored in the memory for the intake time.
T2 is always stored, and the latest data BOT0, the previous data BOT1, and the data BOT2 before the last time are always stored in the memory for the expiration time.

These continuous data groups are superimposed on each data. For example, the latest data is multiplied by a weighting factor of 3, the previous data is multiplied by a weighting factor of 2, and the data two times before is multiplied by a weighting factor of 1. Calculate BIA and expected mean inspiratory time BOA.

In order to obtain the actual valve opening / closing timing (BOW, BIW) from the obtained expected average intake time and the expected average intake time, the expected average intake time BIA and the expected average expiration time BOA are each set to 100 (%). Whether the opening / closing process is to be performed at a time point earlier by% is input in advance, and is obtained as follows.

BOW = BOA × a / 100 BIW = BIA × b / 100 where a and b are an inspiration timing correction coefficient and an expiration timing correction coefficient, respectively.

Based on the above data, when opening and closing the valve, the valve opening timing BOW is substituted into the timer T2 when the intake count is set to 0, and the valve closing timing BIW is set to the timer when the intake count is set to 0. Substitute T1 and then start each timer. When each timer becomes 0, a timer interrupt occurs, and the valve is opened and closed according to the interrupted timer.

Hereinafter, description will be made with reference to actual processing flowcharts shown in FIGS. 9 to 12.

Interrupt preparation During preparation for initial value setting, etc., an interruption prohibition process for prohibiting an external interrupt for data sampling or a timer interrupt by a timer is performed (step S1).

Opening the valve The valve is opened to supply breathing gas (step S2).

Initial Value Setting In order to set an initial value for the calculation, the process proceeds to an initial value setting subroutine shown in FIG. 10 (step S3).

In the initial value setting subroutine, the set value CN of the initial value setting counter is set to 2 (step S7). As a result, the number of loops is set to three.

Next, DA (CN), that is, in the first loop, the sampling data step S _OUT of the output signal of the sensor is stored in DA (2) (step S8).

Next, the counter CN is decremented by 1 (step S9). Since the loop end condition has not been satisfied yet (step S1).
0), and return to step S8 again.

Thereafter, similarly, when DA (0), DA (1), and DA (2) are obtained, the difference DS1 between the previously stored data and the data two times before is obtained.
That is, DS1 = DA (1) -DA (2) and the difference DS0 between the latest stored data and the previous data, that is, DS0 = DA (0) -DA (1) are calculated (step S11).

Next, a predetermined initial value is assigned to each of the intake time memory group and the intake time memory group (step S12),
Return to the main routine.

Next, an intake timing correction coefficient a and an intake timing correction coefficient b are input (step S4).

Since the initial condition setting is completed as described above, the external interrupt is permitted (step S5), and the CPU does nothing and waits for an interrupt of the data processing (step S6).

Data Processing Interrupt FIG. 11 shows a processing flowchart of the data processing interrupt routine.

The controller samples the output signal of the sensor unit every 50 msec and stores the latest sampling data DA (0) in the memory.
, The data DA (0) and DA (1) obtained by the previous sampling and the sampling two times before are sequentially slid and stored in the memory as DA (1) and DA (2), respectively (step S13). .

Then it stores the sampling data S _OUT of the latest sensor output signal as the data DA (0) in the memory (step S1
Four).

Next, the difference DS1 between the previous stored data and the data two times before, ie, DS1 = DA (1) −DA (2), and the difference DS0 between the latest stored data and the previous data, ie, DS0 = DA (0) −DA (1) is calculated (step S15).

Here, assuming that the actual time is between the point b1 and the point a1 in FIG. 8, since DS1 is not 0, it is determined to shift the processing to the counter subroutine (step S1).
6).

Counter Subroutine FIG. 12 shows a processing flowchart of the counter subroutine.

In the counter subroutine, DS1 is determined again (step S27). In this case, since DS1 is positive, the process proceeds to step S28.

At this point, since the exhalation is being performed, the intake counter BOT is counted up by one (step S28), and the process returns to the data processing interrupt routine.

Similarly, during the intake time, steps S27 and S27 are performed.
The process of 28 'is performed, the counter BIT is counted up by one, and the process returns to the data processing interrupt routine.

Calculation of the next valve opening / closing time After a lapse of time, when the point a1 is reached as shown in FIG. 8, it is determined that DS1 = 0 and DS0 <0 as shown in FIG. 11 (steps S16 and S17), As a change point from expiration to inspiration, a predicted average expiration time for calculating the next valve opening timing is calculated (steps S18 to S21). In order to store the latest count value in the memory, the count values BOT0 and BOT1 obtained by the previous count and the count two times before are sequentially slid and stored in the memory as BOT1 and BOT2, respectively (step S18).

Next, the latest counter value is stored in the memory as BOT0 (step S19).

These three consecutive counter values are weighted as follows to calculate an expected average expiration time BOA (step S
20).

Next, the actual valve opening timing BOW is obtained from the expiration timing correction coefficient a input in advance as follows (step S21).

BOW = BOA × a / 100 Further, by the same method (step S18 ′ to step S18).
21 ') The actual valve closing timing BIW is also obtained as follows.

BIW = BIA × b / 100 where the timing correction coefficients a and b are 0 to 99
(%), And a value around 20 (%) is usually appropriate.

Next, the actual valve closing timing BIW is set in the timer T1, and the subtraction is started (step S22).

Next, the intake counter BIT is reset to 0 (step S2
3) Enable the timer interrupt (step S24), and return to the main routine.

Thereafter, similarly, the optimal timing adjustment can be performed by alternately obtaining the valve opening timing and the valve closing timing.

Timer Interrupt Processing When the countdown of the timer T1 or T2 is completed in step 22 or 22 ', a timer interrupt signal is generated, and the process proceeds to a timer interrupt processing routine.

FIG. 13 shows a processing flowchart of the timer interrupt processing routine.

The timer interrupt processing routine determines which timer the interrupt signal is from, and if the interrupt signal is from the timer T1, closes the valve (step S30) and resets the timer T2.
In the case of an interrupt signal from the CPU, the valve is opened (step S32) and timer interrupt prohibition processing is performed (step S3).
1) Return to the original routine.

As described above, the optimal timing valve can be opened and closed.

If there is no output signal from the sensor for a predetermined time (13 seconds in this embodiment), the processing is shifted to the fail-safe interrupt processing routine as shown in FIG. Immediately opens the valve to maintain a state in which respirable gas can be supplied (step S33), and performs alarm processing such as sounding an alarm (step S34).

〔The invention's effect〕

Since the present invention is configured as described above, it is possible to not only supply oxygen-enriched air without impairing the respiratory system of a person, but also to reduce the waste of oxygen-enriched air. Play. In addition, since oxygen-enriched air is discharged before inhalation, it is possible to inform the patient that oxygen-enriched air is released, thereby giving a sense of security. Further, dead volume of the oxygen-enriched air at the end of the intake can be avoided to save the oxygen-enriched air.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an oxygen-enriched air supply device incorporating a respiratory synchronization device of the present invention, FIG. 2 is a configuration diagram of an adsorption-type oxygen concentrator, and FIG. 4 is a plan view of the sensor, FIG. 5 is a plan view of the sensor board, FIG. 6 is a side view of the sensor, FIG. 7 is a configuration diagram of the microcomputer, and FIG. 8 is a signal from the respiration sensor. 9 to 14 are control flowcharts of the controller. FIG. 9 is a main routine, FIG. 10 is an initial value setting subroutine, FIG. 11 is a data processing interrupt routine, and FIG. 12 is a counter subroutine. FIG. 13 is a timer interrupt processing routine, FIG. 14 is a fail-safe routine, FIG.
FIG. 15 is a configuration diagram of a conventional oxygen-enriched air supply system. 1 ... Oxygen enricher, 3 ... ON-OFF switching valve, 4 ...
Controller, 5 ... breath sensor, 7 ... oxygen cylinder,
9 ... Adsorption type oxygen concentrator.

Claims (1)

(57) [Claims] An oxygen-enriched air supply means for supplying oxygen-enriched air to a human body; an oxygen-enriched air supply path for sending oxygen-enriched air to a human body; Provided ON-OFF switching valve, a respiratory sensor attached to the human body for detecting the respiratory state, and a controller for opening and closing the ON-OFF switching valve according to the output signal from the respiratory sensor In the oxygen-enriched air supply device, the controller predicts the next respiratory cycle based on the output signal from the respiratory sensor, opens the ON-OFF switching valve before inhalation starts, and sets O before the start of exhalation.
An oxygen-enriched air supply device characterized by closing an N-OFF switching valve.