JP7290406B2 - Breathing gas supply device and its control method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a breathing synchronized breathing gas supply device for supplying breathing gas such as concentrated oxygen according to a user's breathing cycle, and a control method thereof.

Oxygen inhalation therapy, in which patients are made to inhale high-concentration oxygen gas to compensate for insufficient oxygen, is used as a treatment for respiratory diseases such as asthma, emphysema, and chronic bronchitis. In home oxygen inhalation therapy, a user, who is a patient, operates a respiratory gas supply device such as an oxygen concentrator or an oxygen cylinder according to a doctor's prescription to perform oxygen inhalation therapy at home. Recently, portable oxygen concentrators driven by batteries have been developed, and the applications of respiratory gas supply devices are expanding.

Many of the portable respiratory gas supply devices are breath-synchronized with a demand regulator function in order to reduce the size and weight of the device and enable long-time operation (Patent Documents 1 and 2). The demand regulator function detects the respiratory phase of the user with a pressure sensor or the like, supplies respiratory gas such as oxygen gas only in the inspiratory phase in synchronization with the respiratory cycle, and stops the supply in the expiratory phase. By supplying the breathing gas in pulses according to the breathing cycle of the user instead of supplying it continuously, it is possible to save the breathing gas and reduce power consumption.

As a means for detecting the respiratory phase with the demand regulator function, a method has been devised in which a pressure sensor is installed in the gas supply path that supplies gas to the cannula and the pressure change associated with the respiratory phase is detected. When the value falls below a predetermined pressure value threshold, or when the time rate of change (pressure gradient) of the pressure value from the expiratory phase to the inspiratory phase exceeds a predetermined pressure gradient threshold, the inspiratory phase is There is a way to determine when it has started.

Since the pressure sensor used to detect the respiratory phase has extremely high detection sensitivity, there is a problem of offset where the reference point of the pressure sensor shifts due to the effects of the usage environment such as temperature and the effects of changes over time due to long-term use. . If an attempt is made to detect the start of the inspiratory phase using the pressure value threshold, a shift in the measured value due to the offset causes an error in detecting the start of the inspiratory phase or a delay in the detection timing of the start of the inspiratory phase. For this reason, a method of detecting the start of the inspiratory phase using a pressure gradient threshold, which is less susceptible to the offset, is considered preferable.

Japanese Patent No. 2656530 Japanese Patent Application Laid-Open No. 2004-105230

A person's breathing pattern varies greatly depending on activity conditions such as rest, exertion, and sleep. For this reason, even if the method of judging the start of the inspiratory phase by the pressure gradient threshold is adopted, detection errors of the inspiratory phase start may occur frequently due to changes in the user's activity status, and when using the demand regulator function is one of the problems.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances. The purpose is to provide an apparatus.

The present invention includes the following aspects (1) to (18).
(1) The respiratory gas supply apparatus of the present invention is a respiratory synchronized type respiratory gas supply apparatus that supplies respiratory gas according to the user's breathing cycle, and the pressure in the gas flow path is measured. A sensor, and a control unit that selects one pressure gradient threshold from among a plurality of set pressure gradient thresholds, the control unit calculating from the signal of the pressure sensor , from the expiratory phase to the inspiratory phase side A point at which the magnitude of the gradient of the pressure gradient is larger than the magnitude of the gradient of the selected one pressure gradient threshold is determined as an inspiratory detection point, and the breathing gas is supplied from the inhalation detection point for a certain period of time. and switching the one pressure gradient threshold to one of the plurality of pressure gradient thresholds based on the time required to detect the intake detection point a predetermined number of times.
(2) In (1), the plurality of pressure gradient thresholds includes at least two pressure gradient thresholds, and the controller determines that the time required to detect the intake detection point a predetermined number of times is greater than the first time. If it is longer, the pressure gradient threshold is switched to a pressure gradient threshold with a smaller gradient than the selected pressure gradient threshold, and the control unit determines the time required to detect the intake detection point a predetermined number of times. If it is shorter than the time, the pressure gradient threshold is switched to a pressure gradient threshold having a greater slope than the selected pressure gradient threshold.
(3) In (2), the pressure gradient threshold includes at least a first pressure gradient threshold and a second pressure gradient threshold having a smaller slope than the first pressure gradient threshold, and the first pressure gradient threshold is − 2.4 Pa/20 ms or more and -1.0 Pa/20 ms or less, and the second pressure gradient threshold is -0.8 Pa/20 ms or more and -0.1 Pa/20 ms or less.
(4) In any one of (2) to (4) , the first time is a time corresponding to the time required to detect the intake detection point 1 to 8 times per 60 seconds. and
(5) In (2) or (3), the second time is a time corresponding to the time required to detect the intake detection point 48 times to 60 times in 60 seconds.
(6) In any one of (2) to (5), when the pressure gradient threshold with the smallest slope is selected , the time required to detect the intake detection point a predetermined number of times is the third If it is longer than the time, the control unit switches the supply of the respiratory gas to continuous supply for a certain period of time or pulse supply for a certain period.
(7) In any one of (2) to (6), the third time is a time corresponding to the time required to detect the intake detection point 1 to 10 times per 60 seconds. and
(8) The respiratory gas supply apparatus of the present invention is a respiratory synchronized type respiratory gas supply apparatus that supplies respiratory gas according to the user's breathing cycle, and the pressure in the gas flow path is measured. A sensor, and a control unit that selects one pressure gradient threshold from among a plurality of set pressure gradient thresholds, the control unit calculating from the signal of the pressure sensor , from the expiratory phase to the inspiratory phase side A point at which the magnitude of the gradient of the pressure gradient is larger than the magnitude of the gradient of the selected one pressure gradient threshold is determined as an inspiratory detection point, and the breathing gas is supplied from the inhalation detection point for a certain period of time. and switching the one pressure gradient threshold to one of the plurality of pressure gradient thresholds based on an average value of times between the intake detection points for the most recent multiple times.
(9) In (8), the plurality of pressure gradient thresholds include at least two pressure gradient thresholds, and the control unit determines that the average value of the times between the intake detection points for the most recent multiple times is the first If it is longer than the time, the pressure gradient threshold is switched to a pressure gradient threshold with a smaller gradient than the selected pressure gradient threshold, and the control unit determines the time between the inspiratory detection points for the most recent multiple times. If the average value is shorter than the second time, the pressure gradient threshold is switched to a pressure gradient threshold having a greater slope than the selected pressure gradient threshold.
(10) In (9), the first time is longer than 7.5 seconds.
(11) In (9), the second time is shorter than 1.2 seconds.
(12) In any one of (1) to (11), the breathing gas is concentrated oxygen, and the breathing gas supply device is an oxygen concentrator.
(13) A control method of the present invention is a method of controlling a respiratory-coordinated respiratory gas supply device that supplies respiratory gas in accordance with a user's breathing cycle, wherein a plurality of set pressure gradient thresholds are controlled. A pressure gradient threshold selection step of selecting one pressure gradient threshold from the an intake detection point detection step of detecting an intake detection point where the magnitude of the gradient of the pressure gradient threshold selected in the pressure gradient threshold selection step is greater than the magnitude of the gradient, and the time required to detect the intake detection point a predetermined number of times and a pressure gradient threshold switching step of switching the one pressure gradient threshold to one of the plurality of pressure gradient thresholds based on the threshold.
(14) In (13), the step further comprises a step of supplying a pulse of the respiratory gas for a predetermined period of time when the inhalation detection point is detected in the inhalation detection point detection step.
(15) In (13) or (14), the pressure gradient threshold switching step selects the pressure gradient threshold if the time required to detect the intake detection point a predetermined number of times is longer than a first time. If the time required to detect the intake detection point a predetermined number of times is shorter than the second time, the pressure gradient threshold is switched to the selected pressure gradient threshold. It is characterized by switching to a pressure gradient threshold with a larger gradient than the threshold.
(16) A control method of the present invention is a control method for a respiratory-coordinated respiratory gas supply device that supplies respiratory gas in accordance with a user's breathing cycle, wherein a plurality of set pressure gradient thresholds are controlled. A pressure gradient threshold selection step of selecting one pressure gradient threshold from the An intake detection point detection step of detecting an intake detection point at which the magnitude of the gradient of the pressure gradient threshold selected in the pressure gradient threshold selection step is larger than the average value of the times between the intake detection points for the most recent multiple times. and a pressure gradient threshold switching step of switching the one pressure gradient threshold to one of the plurality of pressure gradient thresholds based on.
(17) In (16), the step further comprises a step of supplying a pulse of the respiratory gas for a predetermined time when the inhalation detection point is detected in the inhalation detection point detection step.
(18) In (16) or (17), the pressure gradient threshold switching step changes the one pressure when the average value of the times between the intake detection points for the most recent multiple times is longer than a first time. If the gradient threshold is switched to a pressure gradient threshold with a smaller gradient than the selected pressure gradient threshold, and the average value of the time between the inspiration detection points for the most recent multiple times is shorter than a second time, The one pressure gradient threshold is switched to a pressure gradient threshold having a larger gradient than the selected pressure gradient threshold.

According to the present invention, it is possible to provide a respiratory gas supply apparatus having a demand regulator function that accurately detects a respiratory phase and supplies an inhalation gas in synchronization with a respiratory cycle.

FIG. 4 is a diagram showing the configuration of the demand regulator function of the respiratory gas supply device; FIG. 10 is a flow diagram of pressure gradient threshold switching; FIG. 10 is a flow diagram of pressure gradient threshold switching including manual switching. FIG. 4 is a flow diagram including switching to automatic continuous delivery of breathing gas. FIG. 4 is a flow diagram including switching to automatic pulsing of breathing gas. FIG. 4 is a diagram schematically showing a breathing pattern during wakefulness and a breathing pattern during sleep;

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 6 schematically shows a breathing pattern during wakefulness and a breathing pattern during sleep of a person. Normally, breathing during sleep is shallow, so in the breathing pattern during sleep (Fig. 6(b)), the pressure amplitude is smaller than in the breathing pattern during wakefulness (Fig. 6(a)). The sideward pressure gradient is also small. Note that the pressure gradient from the expiratory phase to the inspiratory phase of the breathing pattern is always less than zero. In the present invention, the magnitude of the pressure gradient means the magnitude of the absolute value of the pressure gradient.

For example, for the breathing pattern in FIG. 6, the pressure gradient threshold (hereinafter sometimes referred to as "threshold A") is set to -2.0 Pa/20 ms, and the magnitude of the gradient of the pressure gradient measured by the pressure sensor is , and the slope of the threshold value A is set as an intake detection point G, and this intake detection point G is determined as the start of the intake phase. In FIG. 6(a), which is the breathing pattern during wakefulness, the pressure gradient becomes the maximum gradient of −4.0 Pa/20 ms immediately after the change from the expiratory phase to the inspiratory phase, which is larger than the slope of the threshold A. The start of the phase can be detected as an inspiration detection point G.

On the other hand, in FIG. 6(b), which is the breathing pattern during sleep, since breathing is shallower and gentler than during wakefulness, the maximum slope of the pressure gradient is -1.0 Pa/20 ms, which is greater than the slope of the threshold A. less likely to grow. For this reason, the intake detection point G is not detected, and an intake phase start detection error is likely to occur. At this time, if the threshold value A is reset to -0.2 Pa/20 ms, for example, the sensitivity increases and the intake detection point G can be detected even if the maximum gradient is -1.0 Pa/20 ms. However, if the threshold value A is set during wakefulness to match sleep, the sensitivity is too high, and even the noise of the pressure sensor caused by vibrations and slight body movements that occur while carrying the respiratory gas supply device is detected as a pressure change. False detection of the intake detection point G occurs frequently.

The demand regulator function of the respiratory gas supply apparatus of the embodiment is such that the pressure gradient thresholds (threshold A ₁ , threshold A ₂ , threshold A ₃ ) suitable for wakefulness and the pressure gradient threshold (threshold A ₄ ) suitable for sleep are set in advance. Based on the time required for the control unit of the respiratory gas supply device to detect the inspiratory detection point G a predetermined number of times, whether the user is awake or sleeping, and It has a function of judging whether the start of the phase is properly detected and switching among threshold A ₁ , threshold A ₂ , threshold A ₃ , and threshold A ₄ .

FIG. 1 is a diagram showing the main configuration of the demand regulator function of the respiratory gas supply device. In the figure, solid lines indicate gas flow paths, and dotted lines indicate electrical signal paths. The breathing gas supply source 1 is, for example, an oxygen concentrator, an oxygen cylinder, or the like, and supplies inhalation gas at a predetermined pressure and concentration. The control valve 6 is an electromagnetic valve or the like, and is opened and closed by a signal from the control section 5 . The gas supplied from the respiratory gas supply source 1 is supplied to the user from the cannula 2 by opening and closing the control valve 6 controlled by the controller 5 . A pressure sensor 4 is provided in the gas supply path 3 connecting the control valve 6 and the cannula 2 .

In the demand regulator function, the pressure sensor 4 constantly measures the pressure of the gas supply path 3, which fluctuates according to the user's breathing, and transmits the pressure to the controller 5. FIG. The control unit 5 detects the inspiratory detection point G from the real-time respiratory pattern obtained by the pressure sensor 4, judges that the inspiratory detection point G is the start of the inspiratory phase, opens the control valve 6, and allows the cannula 2 to breathe at a constant flow rate. After supplying the gas for a certain period of time, the control valve 6 is closed. In addition, in general, oxygen administered after the first 60% of inspiration stays in the dead space and does not participate in gas exchange in the alveoli. In order to ensure that almost all of the supplied oxygen is used for oxygen exchange in the alveoli, oxygen supply must be completed within about 0.24 to 1.2 seconds after the inspiratory detection point G is detected. is desirable.

In parallel with the control of the control valve 6, the control unit 5 determines the threshold value A used for detecting the intake detection point G from the time required to detect the intake detection point G a preset number of times. Decide if you need to switch. More specifically, the pressure gradient threshold (threshold A ₁ , threshold A ₂ , threshold A ₃ ) suitable for wakefulness or the pressure gradient suitable for sleep is determined based on the time required for detection of the predetermined number of times of the inspiratory detection point G. Threshold A is switched by selecting one of the thresholds (threshold A ₄ ).

FIG. 2 shows a flow in which the control unit 5 determines whether or not the threshold A needs to be switched, and switches the threshold A to the threshold A ₁ , the threshold A ₂ , the threshold A ₃ or the threshold A ₄ .

When the device is activated and the demand regulator function is activated, the control unit 5 sets the threshold A to the pressure gradient threshold (threshold A ₁ ) which is the lowest sensitivity among the pressure gradient thresholds suitable for wakefulness (step S1). Threshold A ₁ , A ₂ , and A ₃ should be set in the range of -4.0 Pa/20 ms to -1.0 Pa/20 ms as a result of measuring and examining the breathing patterns of multiple HOT patients during wakefulness. It is preferable to be in the range of -2.4 Pa / 20 ms to -1.0 Pa / 20 ms, threshold A ₁ is about -4.0 Pa / 20 ms, threshold A ₂ is about -2.0 Pa / 20 ms, threshold A ₃ was found to be more preferably about -1.0 Pa/20 ms. In addition, as a result of measuring and examining the breathing patterns of a plurality of HOT patients during sleep with respect to the threshold _A4 , in order to keep the ratio (detection rate) of the number of intake detection points G to the actual number of breaths at 75% or more, It was found that the threshold _A4 is preferably between -0.8 Pa/20 ms and -0.1 Pa/20 ms, and more preferably about -0.2 Pa/20 ms. When threshold A ₁ , threshold A ₂ , and threshold A ₃ are greater than −2.4 Pa/20 ms, or when threshold A ₄ is greater than −0.8 Pa/20 ms, respectively, In order to keep the user's blood oxygen saturation (SpO2) at 90% or more, which is considered to be a general appropriate value, the detection rate of the inhalation detection point G is less than 75% due to the lack of sensitivity. Insufficient supply of breathing gas. 2 to 5 are examples in which there are four levels of pressure gradient thresholds, where threshold A ₁ is -4.0 Pa / 20 ms, threshold A ₂ is -2.0 Pa / 20 ms, and threshold A ₃ is -1.0 Pa. /20 ms, and the threshold _A4 is -0.2 Pa/20 ms.

In addition, when the threshold A ₁ , threshold A ₂ , and threshold A ₃ are smaller than −1.0 Pa/20 ms, or when the threshold A ₄ is smaller than −0.1 Pa/20 ms, the intake detection point G with respect to the actual number of breaths The detection rate becomes 130% or more. The ratio of erroneous detection of the inspiratory detection point G due to the noise of the pressure sensor 4 increases, and respiratory gas is not supplied in synchronism with the start of the inspiratory phase, so that the user feels uncomfortable and consumes respiratory gas. become more.

The control unit 5 detects the inspiratory detection point G from the threshold value _A1 set in step S1 and the pressure gradient obtained from the signal of the pressure sensor 4, and starts pulse supply of respiratory gas synchronized with the start of the inspiratory phase. .

Next, the control unit 5 stores the timing of the intake detection point G for a predetermined number of times, and stores the timing of the latest intake detection point G and the detection timing of the intake detection point G that is traced back a predetermined number of times. Based on the time difference, it is determined whether or not it is necessary to switch from the threshold _A1 to the threshold _A2 , from the threshold _A2 to the threshold _A3 , and from the threshold _A3 to the threshold _A4 (steps S2, S5, S8). The determination to switch from the threshold _A1 to the threshold _A2 , from the threshold _A2 to the threshold _A3 , and from the threshold _A3 to the threshold _A4 depends on the timing of the inhalation detection point that is _nup times before the latest inhalation detection point G at the time of measurement. The criterion is whether or not the difference exceeds a predetermined time _{t_up} seconds. Since the respiratory rate of humans is generally about 8 to 48 bpm, for example, when the difference in detection timing from the latest inhalation detection point G to the inhalation detection point going back four times exceeds 30 seconds (equivalent to 8 bpm) ((t _up , n _up )=(30, 4)), the current threshold A (threshold A ₁ , threshold A ₂ , or threshold A ₃ ) may not accurately detect the intake detection point G. is high. Therefore, the control unit 5 switches the threshold A to the threshold A ₂ , the threshold A ₃ , or the threshold A ₄ with a one-step higher sensitivity when t _up for four intake detection points is 30 seconds or longer (steps S3, S6, S9).

The n- _up for counting the time t- _up for detecting the intake detection point G a predetermined number of times n- _up is preferably about 3 to 12 times. In addition, the combination of t _up and n _up used as the judgment criteria is not limited to (t _up , n _up )=(30, 4) described above, as long as it satisfies the relationship corresponding to 1 to 8 times per 60 seconds. , any combination of t _up and n _up can be implemented. (For example, (t _up , n _up ) = (30, 3), (60, 3), (60, 4), (60, 5), (60, 6), (60, 7), (60, 8), (90,4), (90,5), (90,6), (90,7), (90,8), (90,9), (90,10), (90,11) , (90, 12), etc.). Combinations of (t _up , n _up ) greater than 8 times per 60 seconds (i.e. less than 60 seconds to detect 8 inspirations), despite correct breath detection, are more sensitive. The possibility of unnecessary switching to a high threshold A increases, and the switching of the threshold due to erroneous detection of the intake detection point G due to disturbances such as body movements frequently occurs, making the user feel uncomfortable. Also, if the n _up is less than 1 per 60 seconds, the switching of the threshold is delayed even though inspiration detection is insufficient, and the threshold A is selected with too low sensitivity for the current patient respiratory pattern. As a result, sufficient respiratory gas cannot be supplied to the user, and the therapeutic effect of the respiratory gas supply device is reduced. 2 to 5 show an example of (t _up , n _up )=(30, 4).

When the pressure gradient threshold is switched to the threshold A4 suitable for sleep in step S9, the control unit 5 detects from the breathing pattern measured by the pressure sensor 4 the point where the pressure gradient is greater than the slope of the threshold _A4 . It is detected as the inspiratory detection point G and pulses of respiratory gas are supplied. By switching the threshold A to the threshold A ₄ , the starting point of the inspiratory layer during sleep, which was likely to be undetectable with the thresholds A ₁ to A ₃ , can now be detected as the inspiratory starting point G.

When the threshold A ₂ , threshold A ₃ or threshold A ₄ is selected, the controller 5 counts the time required for the intake detection point G to be detected a predetermined number of times, and selects thresholds A ₄ to A ₃ , It is determined whether it is necessary to switch from the threshold _A3 to the threshold _A2 or from the threshold _A2 to the threshold _A1 (steps S4, S7, S10). The decision to switch from the threshold _A4 to the threshold _A3 , from the threshold _A3 to the threshold _A2 , or from the threshold _A2 to the threshold _A1 is based on the time required to detect the latest intake detection point G n _down times from the time of measurement. becomes shorter than t _down seconds. As described above, since the respiratory rate of humans is about 8 to 48 bpm, for example, when the inspiratory detection point G is detected four times in less than 5 seconds (equivalent to 48 bpm), ((t _down , n _down )=(5 , 4)), under the condition that the intake detection point G is detected with the current threshold A (threshold A ₂ , threshold A ₃ , or threshold A ₄ ), the sensitivity is too high and noise is erroneously detected as the intake detection point G. likely to be. Therefore, when t _down for four intake detection points is shorter than 5 seconds, threshold A is switched to threshold A ₃ , threshold A ₂ , or threshold A ₁ with one level lower sensitivity (steps S1, S3, S6).

_{The n down for} counting the time t _down required to detect n down a predetermined number of times is preferably about 3 to 60 times. In addition, the combination of t _down and n _down used as the judgment criteria is as long as it satisfies the relationship corresponding to 48 to 60 times per 60 seconds in addition to (t _down , n _down )=(5, 4) described above. Any combination of t _down and n _down is also feasible. (For example, (t _down , n _down ) = (15, 12), (15, 13), (15, 14) (15, 15), (30, 24), (30, 25), (30, 26 ), (30,27), (30,28), (30,29) (30,30), (60,48), (60,49), (60,50), (60,51), ( 60,52), (60,53), (60,54), (60,55), (60,56), (60,57), (60,58), (60,59), (60, 60), etc.). If the threshold t _down of the time required to detect the inspiratory detection point G 48 times is longer than 60 seconds, there is a possibility that unnecessary switching to the threshold A with lower sensitivity is performed even though breathing can be detected correctly. As a result, the patient's respiration cannot be detected correctly, and as a result, sufficient respiratory gas cannot be supplied to the user, and the therapeutic effect of the respiratory gas supply device is reduced. In addition, if the threshold _tdown of the time required to detect the inspiratory detection point G 48 times is shorter than 48 seconds, the current respiration is A too high sensitivity threshold A will continue to be selected for the pattern, and the breathing gas will be pulsed at timings other than inspiration, and the user will likely feel discomfort. 2 to 5 show an example of (t _down , n _down )=(5, 4).

In this way, the control unit 5 determines the time t _up required to detect the intake detection point G a predetermined number of times n _up from the latest intake detection point G, and the predetermined number of times n up from the latest intake detection point G. In order to switch the time t _down required to detect the intake detection point G _down times and the threshold A ₁ , threshold A ₂ , threshold A ₃ , and threshold A ₄ to control the demand regulator function according to the state of the user, The onset of the inspiratory phase can be accurately detected and respiratory gas delivered in phase with the respiratory cycle.

Also, the threshold A ₁ , the threshold A ₂ , the threshold A ₃ , and the threshold A ₄ can be switched based on the average value of the time intervals between the intake detection points G for the most recent multiple times. More specifically, if the average value of the times between the inhalation detection points G for the most recent multiple times is longer than the predetermined time _t1 , it is determined that respiration is not accurately detected, and the threshold A is set to a threshold with a higher sensitivity. Switch to A. Conversely, if the average value of the times between the intake detection points G for the most recent multiple times is shorter than the predetermined time _t2 , it is determined that a disturbance such as body movement is erroneously detected, and the threshold A is set to a threshold with a lower sensitivity. Switch to A. At this time, considering that the human respiratory rate is generally about 8 to 48 bpm, it is desirable that _t1 is longer than 7.5 seconds and _t2 is shorter than 1.2 seconds.

In the above description, as an example of the embodiment, the switchable pressure gradient threshold value A has four steps, but the threshold value A can be set to any number of steps within the range of the above switching method. is also possible, and may be changed continuously.

In the respiratory gas supply apparatus of the embodiment of FIG. 1, the user transmits a sensitivity switching signal from the user interface 7 to the controller 5 to switch the threshold A ₁ , threshold A ₂ , threshold A ₃ and threshold A _{4 .} It can also be done manually. FIG. 3 is an example of a flow in which the sensitivity can be switched by manual operation by the user.

When the device is activated and the demand regulator function is activated, the controller 5 sets the threshold A to the threshold _A1 (step S11). When the user presses the sensitivity increase button of the user interface 7 (step S12), the process proceeds to step S14 and the threshold _A1 is switched to the threshold _A2 . Similarly, when the threshold A is A ₂ , A ₃ (steps S14, S19), pressing the sensitivity increase button (steps S15, S20) proceeds to steps S19, S24, and the threshold A becomes A ₃ , A ₄ . can be switched. Also, when the respiratory gas supply apparatus is controlled with the threshold _A2 and the user presses the sensitivity reduction button (step S16), the process proceeds to step S11 and the threshold is switched to _A1 . Similarly, when the threshold A is A ₃ and A ₄ (steps S19 and S24), pressing the sensitivity reduction button (steps S21 and S25) proceeds to steps S14 and S19, and the threshold A is set to _A2 and _A3 . can be switched. In the example of FIG. 3, the operation of the sensitivity switching button by the user has priority over the determination based on the time t _up and t _down required for the control unit 5 to detect the intake detection point G a predetermined number of times, and the pressure gradient threshold can be switched.

FIG. 4 shows an example in which, in addition to pulsed supply of respiratory gas synchronized with the respiratory phase, a safety function of continuously supplying respiratory gas for about 90 seconds regardless of the respiratory phase is provided. The flow up to step S40 is the same as steps S1 to 10 in FIG. If the time required to detect the intake detection point G four times in step S40 is 5 seconds or more, it was necessary to detect the intake detection point G a predetermined number of times n _backup times from the latest intake detection point G in step S41. Check whether the time is t _backup seconds or longer, and confirm whether the minimum number of breaths during sleep can be detected.

As described above, since the respiratory rate of humans is generally about 8 to 48 bpm, for example, if the time required to detect the intake detection point G four times is 30 seconds or more (equivalent to 8 bpm) ( (t _backup , n _backup ) = (30, 4)), although the control is performed with a highly sensitive threshold value _A4 , the interval between the inhalation detection points G is long and it is possible that the respiratory gas is not sufficiently supplied. highly sexual. Therefore, the control unit 5 switches the supply method of the respiratory gas to continuous supply (automatic continuous flow) (step S42). According to FIG. 1, during the continuous supply of breathing gas, the control valve 6 continues to be in an open state, and the pressure sensor 4 outputs the pressure of the breathing gas as the detection pressure, so pressure fluctuations accompanying breathing are detected during this period. I can't. Therefore, it is necessary to periodically stop the continuous supply of breathing gas and check if the user's breathing has returned to a sufficiently detectable level. The controller 5 resets the threshold A to _A4 and restarts the detection of the intake detection point G (step S45). According to the study of the inventors, as a result of measuring and examining the breathing patterns of a plurality of HOT patients during sleep, the supply time of the auto continuous flow is 10 seconds to 120 seconds. It is highly likely that the breathing gas can be inhaled in the time of , and about 90 seconds is more preferable.

FIG. 5 shows an example in which, in addition to the respiratory gas pulse supply synchronized with the respiratory phase, a safety function is provided to supply the respiratory gas pulse at a constant cycle regardless of the respiratory phase. The flow from steps S51 to S61 is the same as steps S31 to S41 in FIG.

Instead of supplying an automatic continuous flow (step S42 in FIG. 4), the control unit 5 switches the respiratory gas supply method to pulse supply (auto pulse) at a constant cycle (for example, 50 bpm) (step S62). ). Detection of the intake detection point G by the threshold value _A4 is continued even during the period of this auto pulse operation, and when the intake detection point G is detected again, the control unit 5 cancels the auto pulse supply (step S65).

The predetermined number of times n _backup when measuring the time t _backup required to detect the intake detection point G a predetermined number of times is preferably 3 to 12 times. In addition, the combination of t _backup and n _backup used as the judgment criteria is not limited to the above-described (t _backup , n _backup )=(30, 4), as long as it satisfies the relationship corresponding to 1 to 8 times per 60 seconds. , any combination of t _backup and n _backup . (For example, (t _backup , n _backup ) = (30, 3), (60, 3), (60, 4), (60, 5), (60, 6), (60, 7), (60, 8), (90,4), (90,5), (90,6), (90,7), (90,8), (90,9), (90,10), (90,11) , (90, 12), etc.). Note that FIG. 5 shows an example of (t _backup , n _backup )=(30, 4). If the time t _backup required to detect the inspiratory detection point G three times is shorter than 20 seconds, the inhalation can be detected so that the detection rate of the inspiratory detection point G with respect to the actual number of breaths is 75% or more at the threshold value _A4 . Nevertheless, auto-continuous flow or auto-pulse delivery of breathing gas is unnecessarily initiated. Although the risk of desaturation in the patient's blood oxygen can be reduced compared to when oxygen is not supplied by auto-continuous flow or auto-pulse oxygen, it is possible to automatically supply breathing gas regardless of the patient's breathing pattern. Considering that it is a supply method, it does not necessarily satisfy the oxygen amount required by the patient. Therefore, if the respiratory gas supply device is an oxygen concentrator, there is a high possibility that the therapeutic effect will be reduced. Therefore, it is desirable to avoid unnecessary switching to auto-continuous-flow or auto-pulse when inspiratory detection is properly performed and sufficient oxygen is being supplied to the patient as required. In addition, if the time required to detect the respiratory detection point G three times is longer than 180 seconds, the _intake detection point G is hardly detected, and the supply of the auto continuous flow or auto pulse is delayed, and the user is sleeping. Inadequate respiratory gas can be supplied to the patient, reducing the effectiveness of treatment with the respiratory gas supply device. Then, when the condition for switching to auto continuous flow or auto pulse (step S41 or step S61) is satisfied five times in 30 minutes (step S43 or step S63), there is some abnormality in the user or the respiratory gas supply device. It is judged that there is a high possibility of occurrence, and an alarm is sounded (step S44 or step S64).

In the flow of FIGS. 4 and 5, even if the inspiratory detection point G is hardly detected and the demand regulator function cannot sufficiently supply the respiratory gas, the respiratory gas is supplied by auto continuous flow or auto pulse. Automatic supply reduces the risk of the user feeling suffocated.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications, Change is possible.

According to the present invention, the control unit of the respiratory gas supply apparatus switches the pressure gradient threshold for detecting the start of the inspiratory phase according to the user's condition, so that the respiratory phase can be accurately detected and synchronized with the respiratory cycle. It is possible to provide a respiratory gas delivery device with a demand regulator function to deliver inhalation gas at a constant pressure.

1 respiratory gas supply 2 cannula 3 gas supply path 4 pressure sensor 5 controller 6 control valve 7 user interface

Claims (7)

A breath-coordinated breathing gas delivery device for delivering breathing gas in accordance with a user's breathing cycle,
a pressure sensor that measures the pressure in the gas flow path;
A control unit that selects one pressure gradient threshold from among a plurality of set pressure gradient thresholds including at least a first pressure gradient threshold and a second pressure gradient threshold having a slope smaller than the first pressure gradient threshold. and
The control unit detects a point at which the slope of the pressure gradient from the expiratory phase to the inspiratory phase calculated from the signal of the pressure sensor becomes larger than the slope of the selected one pressure gradient threshold. determining the detection point and supplying the respiratory gas for a certain period of time from the inhalation detection point;
If the time required to detect n intake detection points from a predetermined intake detection point is longer than (7.5×n) seconds, the control unit sets the pressure gradient threshold to the selected pressure gradient threshold. Switch to a pressure gradient threshold value with a slope that is one step smaller,
If the time taken to detect the inhalation detection points for the n times is shorter than (1.2×n) seconds, the control unit sets the pressure gradient threshold to a slope larger than the selected pressure gradient threshold. is switched to a pressure gradient threshold that is one step larger,
The first pressure gradient threshold is set within a range of -2.4 Pa / 20 ms or more and -1.0 Pa / 20 ms or less,
The second pressure gradient threshold is set within a range of -0.8 Pa/20 ms or more and -0.1 Pa/20 ms or less,
A respiratory gas delivery apparatus , wherein a plurality of pressure gradient thresholds can be set within each of said first pressure gradient threshold and said second pressure gradient threshold. A breath-coordinated breathing gas delivery device for delivering breathing gas in accordance with a user's breathing cycle,
a pressure sensor that measures the pressure in the gas flow path;
A control unit that selects one pressure gradient threshold from among a plurality of set pressure gradient thresholds including at least a first pressure gradient threshold and a second pressure gradient threshold having a slope smaller than the first pressure gradient threshold. and
The control unit detects a point at which the slope of the pressure gradient from the expiratory phase to the inspiratory phase calculated from the signal of the pressure sensor becomes larger than the slope of the selected one pressure gradient threshold. determining the detection point and supplying the respiratory gas for a certain period of time from the inhalation detection point;
When the average value of the times between the intake detection points for the most recent multiple times is longer than 7.5 seconds, the control unit sets the pressure gradient threshold to a gradient of 1 from the selected pressure gradient threshold. switch to stepwise smaller pressure gradient thresholds,
When the average value of the times between the intake detection points for the most recent multiple times is shorter than 1.2 seconds, the control unit sets the pressure gradient threshold to a gradient of 1 from the selected pressure gradient threshold. switch to a stepwise larger pressure gradient threshold,
The first pressure gradient threshold is set within a range of -2.4 Pa / 20 ms or more and -1.0 Pa / 20 ms or less,
The second pressure gradient threshold is set within a range of -0.8 Pa/20 ms or more and -0.1 Pa/20 ms or less,
A respiratory gas delivery apparatus , wherein a plurality of pressure gradient thresholds can be set within each of said first pressure gradient threshold and said second pressure gradient threshold. When the pressure gradient threshold with the smallest slope is selected, if the time required to detect the intake detection points for the n number of times is longer than (7.5×n) seconds, the control unit 3. The respiratory gas supply apparatus according to claim 1, wherein the supply of the respiratory gas is switched between continuous supply for a certain period of time and pulse supply for a certain period. The respiratory gas supply device according to any one of claims 1 to 3 , wherein the respiratory gas is concentrated oxygen, and the respiratory gas supply device is an oxygen concentrator. A method of controlling a breathing-coordinated breathing gas supply device for supplying breathing gas in accordance with a user's breathing cycle by a control unit, the control unit comprising:
A pressure gradient that selects one pressure gradient threshold from among a plurality of set pressure gradient thresholds including at least a first pressure gradient threshold and a second pressure gradient threshold having a gradient smaller than the first pressure gradient threshold. a threshold selection step;
The magnitude of the slope of the pressure gradient from the expiratory phase to the inspiratory phase calculated from the signal of the pressure sensor that detects the respiratory cycle is the magnitude of the slope of the one pressure gradient threshold selected in the pressure gradient threshold selection step. an intake detection point detection step of detecting an intake detection point that is greater than
If the time taken to detect n inspiratory sensing points from a given inspiratory sensing point is greater than (7.5×n) seconds, then the pressure gradient threshold is greater than the selected pressure gradient threshold. is switched to a pressure gradient threshold that is one step smaller,
If the time required to detect the inspiratory detection points for n times is shorter than (1.2×n) seconds, the pressure gradient threshold is the pressure that is one step larger than the selected pressure gradient threshold. controlling the pressure gradient threshold switching step to switch to the gradient threshold;
The first pressure gradient threshold is set within a range of -2.4 Pa / 20 ms or more and -1.0 Pa / 20 ms or less,
The second pressure gradient threshold is set within a range of -0.8 Pa/20 ms or more and -0.1 Pa/20 ms or less,
A method of controlling a respiratory gas delivery device, wherein a plurality of pressure gradient thresholds can be set within respective ranges of said first pressure gradient threshold and said second pressure gradient threshold. A method of controlling a breathing-coordinated breathing gas supply device for supplying breathing gas in accordance with a user's breathing cycle by a control unit, the control unit comprising:
A pressure gradient that selects one pressure gradient threshold from among a plurality of set pressure gradient thresholds including at least a first pressure gradient threshold and a second pressure gradient threshold having a gradient smaller than the first pressure gradient threshold. a threshold selection step;
The magnitude of the slope of the pressure gradient from the expiratory phase to the inspiratory phase calculated from the signal of the pressure sensor that detects the respiratory cycle is the magnitude of the slope of the one pressure gradient threshold selected in the pressure gradient threshold selection step. an intake detection point detection step of detecting an intake detection point that is greater than
If the average value of the time between the inspiration detection points for the most recent plurality is greater than 7.5 seconds, then the one pressure gradient threshold is one step less than the selected pressure gradient threshold. switch to pressure gradient threshold,
If the average value of the time between the inspiration detection points for the most recent plurality is less than 1.2 seconds, then the one pressure gradient threshold is one step greater than the selected pressure gradient threshold. controlling the pressure gradient threshold switching step of switching to the pressure gradient threshold;
The first pressure gradient threshold is set within a range of -2.4 Pa/20 ms or more and -1.0 Pa/20 ms or less,
The second pressure gradient threshold is set within a range of -0.8 Pa/20 ms or more and -0.1 Pa/20 ms or less,
A method of controlling a respiratory gas delivery device, wherein a plurality of pressure gradient thresholds can be set within respective ranges of said first pressure gradient threshold and said second pressure gradient threshold. When the pressure gradient threshold with the smallest slope is selected, if the time required to detect the intake detection points for the n number of times is longer than (7.5×n) seconds, the control unit 7. The respiratory gas supply apparatus according to claim 5, further comprising a step of switching the supply of the respiratory gas to continuous supply for a certain period of time or pulse supply for a certain period.

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