JPH0819610A - Airway positive pressure type breathing assisting device - Google Patents

Abstract

PURPOSE:To make it possible to get rid of wasteful operation, by controlling a pressure controller and/or a blower to increase the pressure in the system if the absence of breathing is judged a specified number of times within a specified time. CONSTITUTION:A patient 4 puts on a nose mask 3 and turns on the power source of the device. The nose mask 3 is continuously supplied with air at a specified pressure, for example, 0-40mmH2O (gage pressure), and the presence or absence of the patient's breathing is monitored by a pressure sensor 6. When it is detected that the pressure in the system becomes below an initially set level by, for example, 10mmH2O, the presence of breathing is judged, and when it is not detected that the pressure becomes bellow the set level by 10mmH2O, the absence of breathing is judged to set the counter in an MPU 11 to 1. If the frequency of judgments of absence of breathing is, for example, over 5 times in 30 minutes, abnormal breathing is judged, the air flow rate of a blower 1 is increased to change the set pressure to, for example, 500mm2O, and a voice coil type leak valve 5 is opened to decrease the pressure in the system during expiration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive airway-type breathing assistance device for pressurizing atmospheric air and supplying it to a nostril through a nasal mask. More specifically, as a preferred therapeutic means for sleep apnea syndrome, during sleep, pressurized air is sent into the respiratory airway through the nostril to maintain a positive pressure in the airway to maintain a positive pressure in the airway. An apparatus is provided for preventing respiratory arrest resulting from an obstruction.

[0002]

2. Description of the Related Art A conventional non-breathing type positive airway pressure breathing assistance device (also called a CPAP device) has a high positive pressure even during exhalation, and it is difficult to expel exhalation, that is, air. was there. In addition, breath-synchronized positive airway pressure type respiratory assist devices have been developed so far. However, with these positive airway pressure type breathing assistance devices, air is supplied so that the system pressure becomes approximately constant at least during the inspiration period after the operation is started, and the operation is continued continuously. The device is operated even during normal breathing, causing discomfort to the user,
There was often unnecessary power consumption due to useless operation of the device.

[0003]

DISCLOSURE OF THE INVENTION The present invention has been a problem in the conventional positive airway pressure type breathing assistance apparatus, in which air is supplied so as to have a substantially constant system pressure at least during the inspiration period. It is an object of the present invention to provide an improved positive airway pressure breathing assistance device that eliminates the wasteful operation of continuous operation. In other words, a positive airway pressure breathing assistance device that eliminates useless operation of the device as much as possible by adjusting the system internal pressure of the device and suspending / restarting the operation according to the presence or absence of breathing by the user It is the one we are trying to provide.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention intend to prevent unnecessary driving during normal breathing of a user in a conventional positive airway pressure type breathing assistance device to reduce user discomfort as much as possible. As a result of diligent research for the purpose, it was found that it is extremely effective, for example, to determine whether or not the user is breathing and to raise or lower the operating pressure of the device and stop / restart the operation itself based on the result. The present invention has been reached.

That is, the present invention is provided with a blowing means for compressed air for delivering compressed air having a pressure higher than the atmospheric pressure, a conduit means connected to the sending side of the blowing means, and the other end side of the conduit means. A respiratory assistance device comprising:
A pressure adjusting means for adjusting the pressure in the system, a respiratory detecting means for detecting information about at least a part of the respiratory cycle of the user, and the presence or absence of breathing based on the detection result by the respiratory detecting means. And a controlling means for controlling the pressure adjusting means and / or the blowing means in order to increase the pressure in the system by a predetermined value when there is a predetermined number of times of no breathing by the judging means. The present invention provides a positive airway pressure type breathing assistance device, which is equipped with a control means.

In the apparatus of the present invention, the control means is
After increasing the pressure in the system by a predetermined value, it is necessary to further increase the pressure in the system by a predetermined value when the determination means determines that there is no breath for a predetermined number of times. A positive airway pressure breathing assistance device is included that is repeated accordingly.

Further, in the above-mentioned apparatus of the present invention, the control means lowers the pressure in the system by a predetermined value when the judgment means does not judge that there is no breath for a predetermined number of times within a predetermined time. A positive airway pressure type breathing assistance device having a function of repeating the above once or a plurality of times as necessary is included.

Further, in the above-mentioned device of the present invention, the equipment in the system is
Minimum value of constant pressure is 0-40mmH₂ Range of O (gauge pressure)
Includes positive airway pressure breathing assistance within the enclosure. Incidentally, the system
The set pressure inside is 0 mmH₂Device for O (gauge pressure)
With the operation of the system stopped, the set pressure in the system is set to 0 mmH.
₂Operation of the device when increasing O (gauge pressure) by a specified value
Positive airway pressure system also equipped with driving control means for starting
A breathing assistance device is mentioned as a preferred embodiment.

Further, the above-mentioned device of the present invention includes a positive airway-type breathing assistance device in which the maximum value of the set pressure in the system is 300 mmH ₂ O (gauge pressure) or less.

The breathing assistance device of the present invention will be described below.
This will be described in more detail with reference to the drawings as necessary. That is, the breathing assistance apparatus of the present invention includes an internal system pressure adjusting means for adjusting the opening degree of the automatic opening / closing valve means and the leak valve provided in the conduit means, and information on at least a part of the respiratory cycle of the patient, for example, the expiration period. A breathing detecting means for detecting a pressure drop in the system, a judging means for judging the presence or absence of breathing based on the detection result of the breathing detecting means, and an in-system pressure adjusting means and a blowing means as necessary based on the judging result. It is characterized in that it is provided with a control means for automatically changing the setting of the system internal pressure by adjusting the. In such a device, first, the set pressure is lowered to perform positive airway pressure breathing assist operation for supplying air in a continuous mode,
A function to automatically change the system pressure setting to a high value based on a certain criterion for judgment of no breathing within a predetermined time, and to switch to breathing-synchronized positive airway pressure type breathing assistance operation. It is desirable to include it in the control means.

Further, the breathing assistance apparatus of the present invention further sets the system internal pressure when it is judged that there is no breathing after the control system automatically changes the setting of the system internal pressure to a high value by a constant reference. It is desirable to include in the control means a function for repeating the operation of automatically changing the setting to a higher value as necessary. However, the maximum value of the set pressure in that case is preferably about 300 mmH ₂ O (gauge pressure). As a result, the set pressure suitable for the patient's condition can be automatically selected.

Further, the breathing assistance device of the present invention, when the set pressure is increased by the above-mentioned operation, and if it is not judged that there is no breathing within a predetermined time after the elapse of a predetermined time, It is desirable to include in the control means a function for automatically changing the setting of the system internal pressure to a lower standard and repeating the operation as necessary.
In this case, when the set pressure in the system finally becomes sufficiently low, it is necessary to include a function in the control means so as to switch from the breath-tuned type to the continuous mode positive airway pressure type respiratory assist operation. desirable. With these features,
If the patient's breathing returns to normal, adapting to that condition,
It becomes possible to reduce the set pressure to reduce the burden on the patient as much as possible.

In this way, the device of the present invention is adapted to the breathing condition of the user so that the positive airway pressure type respiratory assist operation at the minimum required low set pressure is performed only for the minimum required period. As a result, it has an excellent effect that the burden on the patient can be reduced as much as possible.

Specific examples of the blowing means in the present invention include a blower and a fan for keeping the inside of the system at a positive pressure of, for example, 0 to 300 mmH ₂ O. Examples of the mask means include a cover means having only a small hole provided so that exhaled air can be discharged to the outside, and only a nose, which has a fixing band so that it can be closely attached to the face. Further, as a specific example of the pressure adjusting means in the present invention, in addition to the leak valve, there is an automatic opening / closing valve means which can automatically adjust the opening degree provided in the middle of the conduit means. As a specific example of the respiration detecting means for detecting information relating to at least a part of the breathing cycle, there is one including a diaphragm type pressure sensor provided in the branch pipe in the middle of the conduit means from the air blowing means to the mask means. The pressure sensor may be connected to either the upstream side or the downstream side of the pressure adjusting means, but the downstream side is preferable.

As a concrete example of the judgment means for judging the presence or absence of breathing, a microprocessor unit (M
PU) is used. Specific examples of the control means for the pressure adjusting means and the air blowing means include computer means such as MPU.

Next, a specific example of the breath detecting means for detecting the inspiratory period in the breath-synchronized positive airway pressure type respiratory assist operation of the present invention will be described. Generally, a pressure fluctuation pattern in the system during human respiration when the air supply pressure is switched from the atmospheric pressure to the positive pressure state by using a breathing assistance device is schematically shown in FIG. That is, when the expiratory period is kept at atmospheric pressure and the inspiratory period starts and a predetermined flow rate of air is supplied to the airway to switch to the positive pressure state, as shown in FIG. At the time of starting, the phenomenon that the pressure in the system suddenly drops is seen. After that, when intake is started, air is supplied and begins to become a positive pressure state, the amount of intake decreases and the pressure in the system gradually rises, and the pressure from the part on the balance between the supply of air and intake The rate of increase decreases. Immediately before the end of inspiration and transfer to exhalation, there is a phenomenon in which breathing pauses momentarily and the pressure in the system rises sharply. In addition, after that, the case where the positive pressure state is released and the pressure in the system decreases is shown.

As a specific example of the breath detecting means in the present invention, the pressure (P) in the system is measured by the pressure detecting means,
An example is one in which the pressure change calculation means calculates ΔP / Δt with respect to the time of the pressure (P) in the system to detect the start of intake when the pressure in the system suddenly drops. At this time, it is desirable to control the pressure adjusting means in the system such as a leak valve by the control means so that the supply of air is surely started at the start of intake. That is, when it is detected that ΔP / Δt becomes smaller than a preset first reference value and the pressure in the system sharply decreases, the pressure adjusting means such as closing the leak valve is controlled. To increase the flow rate of the air supplied to the mask means to ensure the intake.

In the breath detecting means of the present invention, the time point at which the pressure in the system suddenly rises is detected as the substantial end of inspiration by similarly calculating ΔP / Δt. At this time, it is desirable to control the pressure adjusting means in the system such as a leak valve so that the pressure in the system is lowered substantially before the expiration is started. That is, △ P
When / Δt becomes larger than a preset second reference value and the pressure in the system rises sharply, it is detected that the leak control valve is opened by a predetermined amount to control the system. The internal pressure is reduced to facilitate exhalation.

[0019]

EXAMPLES The apparatus of the present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

FIG. 2 shows a block diagram of the respiratory assistance device of the present invention. In the apparatus of FIG. 2, a blower fan 1 powered by a DC brushless motor is used as a means for delivering compressed air, and compressed air is supplied to a patient 4 through a humidifier 2 and a nasal mask 3. The doctor's prescription pressure to be applied to the patient 4 is determined by the voltage applied to the DC brushless motor and the opening / closing degree of the voice coil type leak valve 5 provided between the fan 1 and the humidifier 2. The opening / closing degree of the voice coil type leak valve 5 is controlled by the current flowing through the coil.

Further, in the apparatus shown in FIG. 2, a diaphragm type pressure sensor 6 for detecting the fluctuation of the pressure in the system is provided between the humidifier 2 and the nasal mask 3, and the pressure sensor 6 detects the pressure. The pressure signal in the range of −20 to 230 mmH ₂ O (gauge pressure) is converted into an electric signal in the range of 0 to 5 V by the amplifier 7 including an operational amplifier, and
After the high-frequency noise is cut by the 00 Hz low-pass filter 8, the sample-hold circuit 9 holds the data, and the A / D converter 10 sets A at a resolution of 8 bits.
The data obtained by the D / D conversion is taken into the microprocessor unit (MPU) 11.

Further, in this device, the change in pressure is evaluated by ΔP / Δt in the MPU to detect the end of inspiration, and the leak valve 5 is opened based on the detection result, so that the system in the exhalation system is closed. It can reduce the pressure and can also function as a respiratory-assisted breathing assist device.

The breathing assistance apparatus of the present invention can detect the breathing state of the patient 4, determines the presence or absence of breathing according to the detected breathing state, and automatically determines the system according to the determination. By raising and lowering the set pressure inside, the patient's apnea is surely prevented.

Specifically, the patient 4 wears a nasal mask
Turn on the power of the device and start the operation, first 0-40mmH₂O
Air is continuously supplied to the nasal mask at the set pressure (gauge pressure).
Supply and monitor the patient's breathing with the pressure sensor 6
I do. That is, the system pressure is 0 to 40 mmH₂O (gauge
10 mmH from the initial setting pressure₂O went down
If it is detected, it is judged that there is breathing, and that breathing
10 mmH in cycle ₂It is checked that it went down only O
If it is not issued, it is judged that there is no breathing and the cow in the MPU
Set to 1. Counted in this way
If the number of judgments of no breathing is 5 or more within 30 minutes
For example, assuming that it is abnormal breathing, the DC brushless motor
Increase the number of turns to increase the air flow rate of the blower fan 1 and set pressure.
50mmH force₂Switch to O (gauge pressure). Sarako
And the voice coil type reliever during the patient's expiration period.
Breathing type that opens the work valve 5 to lower the system pressure
The positive airway pressure breathing assistance operation of is started.

Thereafter, it was detected that the pressure at the time of decompression corresponding to the expiratory period of the respiratory-assisted positive airway pressure type respiratory assistance operation, that is, 10 mmH ₂ O was lower than the minimum pressure when the leak valve 5 was opened. When (for example, 40 mmH ₂
If it is O (gauge pressure), it is judged that there is breathing when it falls below 30 mmH ₂ O (gauge pressure), and if it is not detected that it is below 10 mmH ₂ O below the minimum pressure in that breathing cycle, then breathing occurs. Judge that there is no MPU
Set the counter inside to 1. If the number of times of determination of no breathing counted in this way is 5 or more within 30 minutes, it is regarded as abnormal breathing, and the rotation speed of the DC brushless motor is further increased to increase the blowing amount of the blowing fan 1. Then, the set pressure is further increased by 20 mmH ₂ O. If necessary, these operations are repeated to allow the patient to operate at a set pressure that does not cause apnea.

Further, the patient's condition may improve, and even the set pressure adjusted as described above may be too high for the patient's condition at that time. Therefore, in the device of FIG. 1, it is detected that the breathing synchronization type positive airway pressure assisted breathing operation is performed at the adjusted set pressure, and the pressure is lower than the minimum pressure when the leak valve 5 is opened by 10 mmH ₂ O. If it is never detected that the pressure has dropped below the minimum pressure by 10 mmH ₂ O once every 2 hours, the DC brushless motor should be set to reduce the set pressure by 20 mmH ₂ O. Lower the rotation speed. Further, the same operation is repeated to reduce the set pressure as needed, and finally the set pressure becomes 50 mmH ₂ O.
When (gauge pressure) is reached, the breathing-synchronized airway positive pressure type breathing assistance operation returns to a constant pressure, that is, 0-40 mmH ₂ O (gauge pressure) continuous airway positive pressure type breathing assistance operation. To do so.

[0027]

According to the breathing assistance device of the present invention, there is an excellent effect that the set pressure can be increased according to the breathing condition of the user to surely prevent the occurrence of apnea. In a particularly preferred embodiment, the airway positive pressure breathing assistance operation at a minimum required low set pressure is performed only for a minimum required period in accordance with the breathing condition of the user so that the burden on the patient can be minimized. It has an excellent effect that it can be reduced.

[Brief description of drawings]

FIG. 1 is an example of a pressure fluctuation pattern during human respiration when atmospheric pressure is switched to a positive pressure state.

FIG. 2 is a schematic illustration of a respiratory assistance device of the present invention.

Claims (5)

[Claims] 1. A blower means for compressed air for delivering compressed air higher than atmospheric pressure, a conduit means connected to a delivery side of the blower means, and a mask means provided on the other end side of the conduit means. A breathing assistance device comprising: a pressure adjusting means for adjusting the pressure in the system; a breath detecting means for detecting information relating to at least a part of a breathing cycle of a user; Determining means for determining the presence or absence of breathing based on the detection result by the means, and for increasing the pressure in the system by a predetermined value when the determination means determines that there is no breathing for a predetermined number of times within a predetermined time. A positive airway-type breathing assistance device comprising control means for controlling a pressure adjusting means and / or a blowing means. 2. The pressure in the system when the control means raises the pressure in the system by a predetermined value and then the determination means determines that there is no breath for a predetermined number of times within a predetermined time. The airway positive pressure type respiratory assistance device according to claim 1, wherein the step of further increasing the above is repeated as required. 3. The control means lowers the pressure in the system by a predetermined value once or when necessary, when the judgment means does not judge that there is no breathing within a predetermined number of times within a predetermined time. The airway positive pressure type respiratory assistance device according to claim 1 or 2, further comprising a function of repeating a plurality of times. 4. The minimum value of the set pressure in the system is 0 to 40.
mmH ₂ O positive airway pressure breathing aid according to any one of claims 1 to 3 in the range of (gauge pressure). 5. The maximum value of the set pressure in the system is 300 mm
The airway positive pressure breathing assistance device according to any one of claims 1 to 3, which has a H ₂ O (gauge pressure) or less.