JP2000300673A - Gas feeding device of breath synchronizing type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breath-synchronizing gas feeding device capable of oxidizing the blood of a patient even in the case of a large number of breathing times such as excessive exertional movement, etc. SOLUTION: The finishing part of an exhalation period nearly free from the variation of breathing air pressure is detected and oxygen is given to obtain sufficient oxidization, to feed oxygen corresponding to the breathing state of the patient and to simultaneously reduce wasteful discharge of oxygen. Namely in a gas feeding device of a breath synchronizing type, which is provided with a generation means of a gas for breathing, a pipe means which communicates with the generation means at its one end, has an open-type feeding means of the gas for breathing at the other end of it and has an automatic switching valve in the middle, a breathing phase detecting means capable of detecting at least a part of prescribed phase in breathing, and a control means for controlling the opening/closing of an automatic switching means based on a breath signal being the detecting result of the detecting means. The control means recognizes the finishing part of an inhalation phase based on hourly variation at the time of and after the peak value of an inhalation signal and opens the automatic switching valve means before starting inhalation.

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 opening / closing valve which can be operated according to a user's breathing cycle. More specifically, therapeutic gases,
For example, the present invention relates to a device for intermittently supplying oxygen gas to a user according to a breathing cycle.

[0002]

2. Description of the Related Art Conventionally, in accordance with a patient's respiratory cycle, oxygen obtained from an oxygen cylinder only during inspiration,
Alternatively, a method has been put to practical use in which by supplying oxygen-enriched gas obtained by an oxygen concentrator, the supply of useless oxygen-enriched gas that is exhausted together with exhalation is prevented and the utilization efficiency is increased.

As such a device, a so-called demand regulator provided with an automatic opening / closing valve provided in the middle of the flow path and a respiratory phase detecting means is used. As a result, oxygen consumption can be reduced to about 1/3. Such savings are especially effective when the patient goes out with the oxygen cylinder, and the travel time can be extended three times.

As means for further reducing the release of useless oxygen, as described in JP-T-58-500005, only an initial short period of time during inhalation of a respiratory cycle, for example, about 0.25 seconds is supplied. Accordingly, means for achieving a blood oxygen concentration equivalent to that of the above method have been proposed.

[0005]

According to these methods,
Although it seems that the useless reduction of oxygen release has been achieved, there are still points that need to be improved in terms of oxygenation during exertion and securing blood oxygen concentration when the user is working or exercising. .

At the start of breathing, the dead space region in the human body from the nasal cavity to the nasopharynx, which is not involved in oxygen absorption, is filled with the immediately preceding expiration. When oxygen is supplied later, the air having a low oxygen concentration in the dead space region is re-breathed in the early stage of inhalation, and a state occurs in which the administered oxygen does not efficiently contribute to oxygenation. In particular, when the respiratory frequency or tidal volume increases due to excessive exertion and when the human body needs a large amount of oxygen, even if oxygen is administered during inspiration, sufficient oxygen such as a decrease in the blood oxygen concentration of the patient is obtained. In some cases, the conversion has not been completed.

[0007] This tends to be more remarkable in an apparatus that saves oxygen consumption, such as the apparatus described in Japanese Patent Publication No. 58-500005.

In order to solve this, it is useful to supply oxygen before the start of inhalation to fill the nasal cavity with oxygen. In that case, in the method of recognizing the initial stage of inspiration and opening the automatic on-off valve as in the conventional control means, it is necessary to recognize before the start of inspiration and open the automatic on-off valve, and to fill the nasal cavity with oxygen at the start of inspiration. Is impossible. In addition, for example, a method of using a pressure sensor as the respiratory phase detecting means and opening an automatic opening / closing valve when the respiratory pressure becomes equal to the atmospheric pressure can be considered. Not realistic when considered. Another possible method is to store past changes in the respiratory phase, predict them, and open the automatic on-off valve.However, during work or exercise, the respiratory cycle increases more than usual. There is no guarantee that the oxygen can be efficiently contributed to oxygenation because it tends to be indefinite.

[0009]

The inventor of the present invention has conducted intensive studies with the aim of solving the above-mentioned problems. As a result, the period before the patient started inhaling, that is, the expiration period during which there was almost no change in the respiratory pressure. By detecting the terminal part and administering oxygen, sufficient oxygenation can be obtained even during exertion, and it is possible to further reduce wasteful release of oxygen while supplying oxygen corresponding to the patient's respiratory condition It was found that.

That is, the present invention has a breathing gas generating means, one end communicating with the generating means, an open type supplying means for the breathing gas at the other end, and an automatic opening / closing valve means in the middle. Respiratory synchronization comprising conduit means, respiratory phase detecting means capable of detecting at least a part of a predetermined phase in respiration, and control means for controlling opening and closing of the automatic opening / closing valve means based on a respiratory signal detected by the detecting means. In the type gas supply device, the control means includes means for recognizing the end of expiratory phase based on the time change of the respiratory signal, and based on the time change after the peak value of the expiratory signal, the end of expiratory phase. And a means for opening the automatic opening / closing valve means before inhalation is started.

Further, according to the present invention, the control means recognizes a point in time when an absolute value of a time change amount after the peak value of the exhalation signal becomes 2 Pa / sec or less as an end-of-expiratory-phase part, and controls the automatic opening / closing valve means. It is an object of the present invention to provide a respiratory-tuned gas supply device which is a means for opening before the start of an inspiratory phase.

Further, the present invention has a means for generating breathing gas, one end communicating with the generating means, an open supply means for the breathing gas at the other end, and an automatic opening / closing valve means on the way. Respiratory synchronization comprising conduit means, respiratory phase detecting means capable of detecting at least a part of a predetermined phase in respiration, and control means for controlling opening and closing of the automatic opening / closing valve means based on a respiratory signal detected by the detecting means. In the type gas supply device, the control means recognizes a state in which the ratio between the time from the peak of the respiratory signal in the immediately preceding expiratory phase to the end of the expiratory phase and the respiratory cycle is 0.4 or more as the end of expiratory phase, It is an object of the present invention to provide a respiratory-tuned gas supply device which is a means for opening the automatic opening / closing valve means before the start of inspiration.

According to the present invention, the control means recognizes the end of expiratory phase based on the average of the ratio of the time from the peak of the respiratory signal in the immediately preceding expiratory phase to the end of the expiratory phase and the respiratory cycle at least twice in the past. Further, the present invention provides a respiratory-tuned gas supply device characterized in that the automatic opening / closing valve means is opened.

Further, the present invention has a means for generating breathing gas, one end communicating with the generating means, an open supply means for the breathing gas at the other end, and an automatic opening / closing valve means on the way. Respiratory synchronization comprising conduit means, respiratory phase detecting means capable of detecting at least a part of a predetermined phase in respiration, and control means for controlling opening and closing of the automatic opening / closing valve means based on a respiratory signal detected by the detecting means. In this type of gas supply apparatus, the control means recognizes, as the end of expiratory phase, a state in which the ratio is less than 20% of the peak value of the respiratory signal in the immediately preceding expiratory phase, and the automatic opening / closing valve means before inhalation starts. The present invention provides a respiratory-tuned gas supply device characterized in that it is a means for opening a gas supply.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The respiratory-tuned gas supply device of the present invention detects a transition period from exhalation to inspiration, which is a region where there is almost no pressure fluctuation at the end of the expiration period, and at this time a pulse of respiratory gas is used. Is supplied to and stored in the nasal cavity, and allows the user to inhale breathing gas, for example, oxygen, without delay at the beginning of inhalation.

According to the present invention, there is provided a breathing gas generating means, and conduit means having one end communicating with the generating means and having an open type supply means for the breathing gas at the other end and an automatic opening / closing valve means in the middle. ,
It basically comprises a demand regulator which is a means for controlling the supply amount of breathing gas by controlling the opening time of the automatic opening / closing valve means.

The respiratory gas generating means of the present invention comprises a respiratory gas generating source, a pressure adjusting means for adjusting the gas from the generating source to a predetermined pressure, that is, a pressure near the atmospheric pressure, and, if necessary, a flow rate setting means. Consists of The source can be of the cylinder type, such as an oxygen cylinder. Since the gas from these sources is usually supplied at a considerably high pressure, the pressure is adjusted to a pressure near the atmospheric pressure by using a pressure adjusting means such as a pressure reducing valve.
For example, 20 kPa to 300 kPa, preferably 100 kPa
Reduce pressure to Pa-200 kPa.

The flow rate setting means may be a method of supplying at a maximum flow rate or a means capable of freely setting a flow rate lower than the maximum flow rate. To the gas user or patient.

This conduit means usually uses a thin plastic tube connected to the gas generating means, and the other end has a jig such as a nasal cannula or a mouth for facilitating the supply of gas to the patient. It is a nasal mask. This conduit means passes through an automatic flow passage opening / closing means in the demand regulator described later, and may be connected to the respiratory phase detecting means of the demand regulator.

The control means (demand regulator) for controlling the opening / closing of the automatic opening / closing valve means according to the present invention opens and closes the automatic opening / closing valve means provided in the middle of the conduit means under specific control conditions, so that the patient can be opened and closed. Is to control the gas supply amount. The demand regulator is basically composed of respiratory phase detecting means having a function of detecting at least a part of a predetermined phase in respiration, control means for controlling opening and closing of the automatic opening and closing valve means, and the automatic opening and closing valve means. It is composed of

As the respiratory phase detecting means,
(A) A method to detect the temperature difference between inspiration and expiration; (b) A method to detect the movement of the chest by installing a sensor that detects the expansion and contraction and converts it into an electric signal in a band wrapped around the chest (C) By inspiration and expiration
A flow rate detection method that detects a change in gas flow or pressure; any of these methods is known, and any of them can be used, but is easily achieved by detecting the gas pressure at the cannula portion at the end of the conduit. it can.

The automatic opening / closing valve means may be of any type as long as the gas flow in the conduit can be stopped or circulated by a signal from the control means. For example, an air valve type that opens and closes a valve by air pressure and a solenoid valve that opens and closes a valve by electric energy can be exemplified, but an electromagnetic valve can be used simply.

The control means includes means for obtaining a respiration cycle, an inspiration time, and an expiration time based on a respiration signal sent from the respiration phase detection means; means for recognizing an end-of-expiration period based on the respiration signal; It is basically composed of opening / closing time setting means and opening / closing adjusting means of the automatic opening / closing valve means.

The means for obtaining the respiratory cycle recognizes a state in which the same pattern is repeated from the change pattern of the respiratory signal sent from the respiratory phase detecting means, and obtains a cycle (one pattern time) of the change pattern. Can be The cycle may be determined as the time from the start of a certain inspiration to the start of the next inspiration, or the time from the peak of a certain expiration signal to the peak of the next expiration signal.

The cycle is preferably obtained by averaging a plurality of cycles, and may be simply obtained by averaging two times. Similarly, the expiration time and / or the inspiration time of the same respiratory cycle are obtained.

The means for recognizing the end of expiratory phase in the present invention is based on the respiratory signal sent from the respiratory phase detecting means at the end of the expiratory period, based on the fact that its time change is small, Recognize the end of the expiration period. For example, when the method of detecting the gas pressure in the cannula portion is used as the respiratory phase detecting means, if the state in which the absolute value of the time variation is 2 Pa / sec or less continues for 300 msec, it is recognized as the end of the expiration period. Can be.
In this case, in order to eliminate the influence of disturbance, 3
It is desirable to use a moving average value of the number of times or more.

As means for recognizing the end of expiratory phase in the present invention, the ratio of the respiratory cycle obtained by the means for obtaining the respiratory cycle to the time from the peak of the expiratory signal to the start of the next inspiration is calculated. Means for recognizing a state where the ratio becomes 0.4 or more as the end portion of the expiration period can be used. Normally, at the end-expiration end, there is a transition period with almost no pressure fluctuation.However, depending on the patient, there may be no transition period and the displacement from expiration to inspiration may occur immediately. It is suitable for detecting For example, after detecting the peak of the expiration signal, constantly calculate the ratio of the time from the start of inspiration or the end of expiration in the previous breath to that point in time and the time from the peak of the expiration signal to that point, and the ratio is calculated. The state of 0.4 or more is recognized as the end of the expiration period. In a healthy person, the ratio until end-expiration (at the start of inspiration) is usually about 0.5 to
It has been found that the present invention exhibits a value of 0.6, and in the present invention, the respiratory gas can be supplied to the end-expiratory end portion by opening the automatic opening / closing valve at an earlier time by such means.

Further, the value of the ratio of the state recognized as the end-expiratory phase can be calculated from the average value of the ratio for the last two breaths. For example, if the ratio between the previous two respiratory cycles and the time from the peak of the expiration signal to the start of the next inspiration is 0.45, the state where the ratio for the next respiration is 0.45 or more Is recognized as the end of the expiratory phase.

Further, as another recognizing means, it is possible to recognize the end portion of the expiration period by referring to the peak value of the immediately preceding exhalation signal. With this method, even if the measured value of the atmospheric pressure by the respiratory phase detecting means changes with time, it can be recognized. For example, when the method of detecting the gas pressure in the cannula portion is used as the respiratory phase detecting means, when the peak value of the immediately preceding exhalation signal is 40 Pa, the state in which the respiration signal becomes smaller than 6 Pa, which is 15%, is defined as the expiration period. Recognize the terminal part. By this means, the patient's breathing becomes indefinite, and even when breathing in which there is little change in the respiratory pressure does not appear, the automatic opening / closing valve means can be opened at the end of the expiration period.

The prescribed flow rate is the flow rate required by the patient as determined by the physician. The oxygen supply device of the present invention is for assisting the patient's breathing, and since not all the gas supplied from the device enters the patient's airway, the prescribed flow rate is required by the patient's body. Is not the same as the absolute value. It is a value determined by the doctor as the prescribed flow rate in the treatment means such as the present apparatus. This value is usually determined separately at rest and during exertion, and a method of inputting respective prescription flow rates is adopted.

The opening / closing time setting means and the opening / closing adjusting means of the automatic opening / closing valve means are controlled based on the prescribed flow rate. In the present invention, based on such values, the flow rate per pulse is expressed by the following formula: flow rate / pulse (cc /-) = prescribed flow rate (cc / min) × oxygen saving rate (-) / respiratory cycle number ( −) Is calculated.

By opening the automatic opening / closing valve means at the end of the detected expiration period, it becomes possible to administer oxygen before the patient starts inhalation.

[0033]

[Embodiment 1] FIG. 3 shows an example of a preferred embodiment of the respiratory gas supply device of the present invention.
That is, the oxygen that has come out of the oxygen cylinder 1 that is the means for generating respiratory gas passes through the pressure reducing valve 101 and the pressure regulating valve 102, and then passes through the conduit means 5 having the orifice type flow rate setting device 2 and the automatic opening / closing valve means 3. And is released from the nasal cannula 7, which is an open supply means.

Respiratory phase detecting means 9 provided with a diaphragm type minute pressure fluctuation sensor provided at a branch from conduit means 5
Thus, the pressure fluctuation in the respiration is converted into the fluctuation of the capacitance and transmitted to the control means 10.

FIG. 4 is a diagram showing the relationship between the end of the expiration period and the amount of change in the respiratory signal in a certain respiratory pattern.
The control means 10 converts the respiratory phase data, constantly captures it as a respiratory signal, and calculates a five-time moving average of the respiratory signal. As a result of calculation, the absolute value of the five-time moving average is 2 Pa / s
When the state of ec continues for 300 msec, the end of the expiration period is determined, and the automatic on-off valve 3 is opened.

Embodiment 2 FIG. 5 is a diagram showing a respiratory cycle and a ratio from a peak value of an expiration signal to the start of the next inspiration. As in the first embodiment, the respiratory phase data is converted and constantly taken in as a respiratory signal. The average value of the ratio between the previous two respiration cycles and the time from the peak of the expiration signal to the start of the next inspiration is calculated and stored as a reference value. After detecting the peak of the respiratory signal,
The ratio of the elapsed time from the start of the immediately preceding inhalation to the elapsed time from the peak of the expiration signal is calculated, and the time when the reference value reaches 90% is determined as the end of the expiration period, and the automatic on-off valve 3 is opened.

[0037]

The respiratory-tuned gas supply device of the present invention makes it possible to further increase the gas absorption utilization efficiency of the user. For example, when oxygen gas is used, the blood oxygen concentration is maintained even during exertion. It becomes possible. Further, the amount of oxygen used can be further reduced as compared with the conventional apparatus, and convenience such as expansion of the range of action of the user can be improved, for example, when the user goes out with a cylinder.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between an oxygen supply pattern and a user breathing pattern of a respiratory-tuned gas supply device of the present invention.

FIG. 2 is a diagram showing a relationship between an oxygen supply pattern and a user's breathing pattern of a conventional breath-tuned gas supply device.

FIG. 3 is an example of an embodiment of a breath-tuned gas supply device of the present invention.

FIG. 4 is a diagram showing a relationship between an end portion of an expiration period in a respiration pattern and a respiratory signal change amount.

FIG. 5 is a diagram showing the ratio of the time from the start of inspiration to the time after passing the peak value of the expiration signal, and the temporal change in the ratio of the peak value of the expiration signal and the ratio of the respiration signal immediately before each breathing cycle.

Claims (5)

[Claims] 1. Respiratory gas generating means, a conduit means having one end communicating with the generating means and an open-type supplying means for the respiratory gas at the other end, and an automatic opening / closing valve means on the way. A respiratory phase detecting means capable of detecting at least a part of a predetermined phase in the above, and a control means for controlling opening and closing of the automatic opening / closing valve means based on a respiratory signal as a detection result of the detecting means. In, the control means comprises means for recognizing the end of expiratory phase based on the time change of the respiratory signal, recognizing the end of expiratory phase based on the time change after the peak value of the expiratory signal, A respiratory-tuned gas supply device, wherein the automatic opening / closing valve means is opened before the start of inspiration. 2. The control means recognizes, as an end of expiration phase, a point in time when an absolute value of a time change amount after the peak value of the exhalation signal becomes 2 Pa / sec or less, and starts the automatic on-off valve means. 2. The respiratory-tuned gas supply device according to claim 1, wherein the device is a front opening means. 3. Respiratory gas generating means, and a conduit means having one end communicating with the generating means and having an open type supply means for the respiratory gas at the other end, and an automatic opening / closing valve means in the middle. A respiratory phase detecting means capable of detecting at least a part of a predetermined phase in the above, and a control means for controlling opening and closing of the automatic opening / closing valve means based on a respiratory signal as a detection result of the detecting means. In, the control means recognizes a state in which the ratio of the time from the peak of the respiratory signal in the immediately preceding expiratory phase to the end of the expiratory phase and the respiratory cycle is 0.4 or more as the end of expiratory phase, and before the start of inspiration, A respiratory-tuned gas supply device which is a means for opening the automatic opening / closing valve means. 4. The control unit recognizes the end of expiratory phase based on the average value of the ratio of the time from the peak of the respiratory signal in the immediately preceding expiratory phase to the end of the expiratory phase to the end of the respiratory cycle two or more times in the past. 4. The automatic opening / closing valve means is opened.
A respiratory-tuned gas supply device as described. 5. Respiratory gas generating means, breathing gas generating means, one end communicating with the generating means, open-type supplying means for breathing gas at the other end, and conduit means having automatic opening / closing valve means on the way. A respiratory phase detecting means capable of detecting at least a part of a predetermined phase in the above, and a control means for controlling opening and closing of the automatic opening / closing valve means based on a respiratory signal as a detection result of the detecting means. In the above, the control means recognizes a state of less than 20% of the peak value of the respiratory signal in the immediately preceding expiratory phase as the end of expiratory phase, and opens the automatic opening / closing valve means before the start of inspiration. A respiratory-tuned gas supply device.