JP2020199101A - CPAP system and CPAP device - Google Patents

Abstract

To remedy a problem that a patient using a CPAP has a trouble of breathing.SOLUTION: A CPAP system includes: a fan for sucking air and sending it out; a sensor for measuring a pressure or a flow rate of the air sent out by the fan; a case incorporating the fan and the sensor, which includes an air inflow port through which the air to be sent to the fan is allowed to flow in and an air outflow port through which the air sent out from the fan is allowed to flow out; a motor drive part for controlling the number of rotations of a motor for rotating the fan by a PWM signal based on the pressure or the flow rate measured by the sensor; a valve for adjusting the pressure or the flow rate of the air supplied from the air outflow port to a mask mounted onto a patient through a tube; and a valve drive part for opening/closing the valve based on the PWM signal. The valve drive part includes a synthesis part for synthesizing a three-phase signal for driving the motor based on the PWM signal, and the valve drive part opens/closes the valve based on the synthesis signal acquired by the synthesis of the three-phase signal by the synthesis part.SELECTED DRAWING: Figure 4

Description

The present invention relates to a CPAP (Continuous Positive Airway Pressure) system and a CPAP device.

CPAP is a treatment that sends mechanically pressurized air through the nose into the airways to widen the airways and prevent apnea during sleep. CPAP is an effective treatment for sleep apnea syndrome.
The CPAP system pumps pressurized air through the nose into the airways. The CPAP system consists of a CPAP device that delivers air, a tube that delivers air at a preset pressure, and a mask that is applied to the nose.
Patients with sleep apnea wear a mask during sleep. The magnitude of the pressure has two patterns, one is to keep a constant pressure at all times and the other is to automatically increase the pressure according to the apnea, and the pressure is set by the doctor according to the patient's medical condition.

Regarding the CPAP device, a technique capable of accurately detecting the pressure of the air to be detected is known (see, for example, Patent Document 1). In this technique, the pressure sensor is provided inside the CPAP device and has a first port through which air discharged from the discharge port of the CPAP device is guided and a second port as an open port, and discharges from the discharge port. Detects the pressure of the air being produced. The opening is provided in the housing of the CPAP device and communicates with the outside of the CPAP device. The tube connects the opening to the second port of the pressure sensor.

JP-A-2018-78997

The CPAP device controls the pressured air to be pumped through the nose into the airways when the patient is inhaling, and to reduce the pressure when the patient is exhaling. However, when the patient is exhaling air, the control to reduce the pressure may not catch up. In this case, the patient may have difficulty breathing because the patient continues to be supplied with excessive air while exhaling.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a CPAP system and a CPAP device capable of improving the difficulty of breathing of a patient using CPAP.

(1) In view of the above problems, the CPAP system according to one aspect of the present invention includes a fan that sucks in and sends out air, a sensor that measures the pressure or flow rate of the air sent out by the fan, and the fan and the above. Based on a case having a built-in sensor and an air inlet for inflowing air sent into the fan and an air outlet for letting out air sent out from the fan, and the pressure or flow rate measured by the sensor. The pressure or flow rate of air supplied from the air outlet to the mask attached to the patient via the tube is adjusted with the motor drive unit that controls the rotation speed of the motor that rotates the fan by a PWM signal. A valve and a valve drive unit that opens and closes the valve based on the PWM signal are provided, and the valve drive unit includes a synthesis unit that synthesizes a three-phase signal that drives the motor based on the PWM signal. The valve driving unit opens and closes the valve based on the combined signal obtained by the combined unit combining the three-phase signal.

(2) In the CPAP system according to one aspect of the present invention, the valve drive unit includes a determination unit that determines the rotation speed of the motor based on the duty ratio of the combined signal, and the valve drive unit is the valve drive unit. The valve may be opened and closed based on the result of the determination unit determining the rotation speed of the motor.

(3) In the CPAP system according to one aspect of the present invention, the determination unit determines that the motor is accelerating when the value obtained by converting the duty ratio of the combined signal into a voltage is equal to or greater than the threshold value, and the motor is accelerated. When the value obtained by converting the duty ratio of the combined signal into a voltage is less than the threshold value, it may be determined that the motor is decelerating.

(4) In the CPAP system according to one aspect of the present invention, the valve drive unit is a generation unit that generates a pulse for driving the valve based on the result of the determination unit determining the rotation speed of the motor. You may be prepared.

(5) In the CPAP system according to one aspect of the present invention, the generation unit may adjust the width of the generated pulse.

(6) In the CPAP system according to one aspect of the present invention, a first voltage level conversion unit that lowers the voltage level of the PWM signal and a second voltage level conversion unit that raises the voltage level of the pulse generated by the generation unit. And may be provided.

(7) The CPAP device according to one aspect of the present invention incorporates a fan that sucks in and sends out air, a sensor that measures the pressure or flow rate of the air sent out by the fan, and the fan and the sensor. The fan is rotated based on a case having an air inlet for inflowing air sent into the fan and an air outlet for discharging air sent out from the fan, and the pressure or flow rate measured by the sensor. A motor drive unit that controls the rotation speed of the motor to be operated by a PWM signal, a valve that adjusts the pressure or flow rate of air supplied from the air outlet to a mask attached to the patient via a tube, and the PWM signal. The valve drive unit includes a valve drive unit that opens and closes the valve based on the above, and the valve drive unit includes a composite unit that synthesizes a three-phase signal that drives the motor based on the PWM signal. Opens and closes the valve based on the combined signal obtained by the combining unit synthesizing the three-phase signal.

According to the present invention, it is possible to provide a CPAP system and a CPAP device that can improve the difficulty of breathing of a patient using CPAP.

It is a figure which shows an example of the CPAP system of embodiment of this invention. It is a figure which shows an example of the characteristic which showed the relationship between the flow rate of the air sent out by a CPAP apparatus, and the static pressure, with the rotation speed of a fan as a parameter. It is a figure which shows an example of the characteristic figure which shows the response time. It is a figure which shows an example of the CPAP apparatus of embodiment of this invention. It is a figure which shows an example of a PWM signal. It is a figure which shows an example of the characteristic figure which shows the response time of the CPAP system of embodiment of this invention. It is a block diagram which shows the valve drive part of the CPAP apparatus of embodiment of this invention. It is a figure which shows an example of the operation of the valve drive part of the CPAP apparatus of embodiment of this invention. It is a flowchart which shows an example of the operation of the CPAP system of embodiment of this invention. It is a figure which shows an example of the operation of the valve drive part of the CPAP apparatus of embodiment of this invention. It is a figure which shows an example of the operation of the valve drive part of the CPAP apparatus of embodiment of this invention. It is a figure which shows an example of the CPAP apparatus of the modification of embodiment of this invention. It is a flowchart which shows an example of the operation of the CPAP system of the modification of the embodiment of this invention.

Next, the CPAP system and the CPAP device of the present embodiment will be described with reference to the drawings. The embodiments described below are merely examples, and the embodiments to which the present invention is applied are not limited to the following embodiments.
Further, "based on XX" in the present application means "based on at least XX", and includes a case where it is based on another element in addition to XX. Further, "based on XX" is not limited to the case where XX is directly used, but also includes the case where XX is calculated or processed. "XX" is an arbitrary element (for example, arbitrary information).

(Embodiment)
Hereinafter, embodiments according to the present invention will be described with reference to the drawings. Configurations having the same or similar functions are designated by the same reference numerals, and duplicate description regarding the configurations may be omitted.
(Overview of CPAP system)
FIG. 1 is a diagram showing an example of a CPAP system according to an embodiment of the present invention.
The CPAP system 100 includes a CPAP device 200, a tube 300, and a mask 400.
The CPAP device 200 includes a case having an air inlet that allows air to flow in, an air outlet that allows air to flow out, a fan, a pressure sensor, and a valve 250. The fan and the pressure sensor are built in the case.
The fan sucks air into the CPAP device 200 from the air inlet and sends the sucked air to the tube 300 connected to the air outlet of the CPAP device 200.
The pressure sensor measures the pressure of the air sent by the fan to the CPAP device 200.
The valve 250 regulates the pressure of air supplied from the air outlet to the mask 400 via the tube 300.
The tube 300 is connected to the air outlet of the CPAP device 200 and sends the air sent by the fan to the mask 400.
The mask 400 is connected to the tube 300 and attached to the patient PA. The mask 400 delivers the air delivered by the CPAP device 200.

FIG. 2 is a diagram showing an example of characteristics showing the relationship between the flow rate of air sent out by the CPAP device and the static pressure with the rotation speed of the fan as a parameter. In FIG. 2, the horizontal axis is the flow rate [slpm] of the air sent out by the CPAP device 200, and the vertical axis is the pressure [kPa].
Further, FIG. 2 shows a case where the rotation speed of the fan is changed to 20000 r / min, 25000 r / min, 30000 r / min, 35000 r / min, and 40,000 r / min. As the rotation speed of the fan increases, the pressure (static pressure) obtained also increases.
Further, FIG. 2 shows an example of the region used by a alternate long and short dash line. The region used here is represented by a range of flow rates and a range of pressures. Specifically, the range of the flow rate used is about 10 [slpm] to 140 [slpm], and the range of the pressure used is about 0.3 [kPa] to 4.5 [kPa].
The pressure obtained when the flow rate of the air sent out by the CPAP device 200 is 20 [slpm] to 100 [slpm] and the rotation speed of the fan is 20000 [r / min] is 0.6 [kPa] to 1.1. It is about [kPa]. The pressure obtained when the flow rate of the air sent out by the CPAP device 200 is 20 [slpm] to 100 [slpm] and the rotation speed of the fan is 25000 [r / min] is 1.2 [kPa] to 1.8. It is about [kPa]. The pressure obtained when the flow rate of the air sent out by the CPAP device 200 is 20 [slpm] to 120 [slpm] and the rotation speed of the fan is 30,000 [r / min] is 1.8 [kPa] to 2.5. It is about [kPa]. The pressure obtained when the flow rate of the air sent out by the CPAP device 200 is 20 [slpm] to 140 [slpm] and the rotation speed of the fan is 35000 [r / min] is 2.5 [kPa] to 3.5. It is about [kPa]. The pressure obtained when the flow rate of the air sent out by the CPAP device 200 is 30 [slpm] to 110 [slpm] and the rotation speed of the fan is 40,000 [r / min] is 3.9 [kPa] to 4.5. It is about [kPa].

Here, assuming that the flow rate is 125 [slpm] and the rotation speed of the fan is adjusted between 20000 r / min and 35000 r / min, it is between 0.5 [kPa] and 2.5 [kPa]. The case of adjusting the pressure with is described. That is, the fan speed is increased from 20000 [r / min] to 35000 [r / min] so that when the patient is inhaling air, pressured air is sent from the nose to the airways, and the patient pumps the air. The fan speed is reduced from 35,000 [r / min] to 20,000 [r / min] in order to reduce the pressure when spitting.

FIG. 3 is a diagram showing an example of a characteristic diagram showing a response time. In the example shown in FIG. 3, 0.5 [kPa] and 2.5 [kPa] by adjusting the fan speed between 20000 r / min and 35000 r / min at a flow rate of 125 [slpm]. An example of the response time when adjusting the pressure between and is shown.
The time required to increase the fan speed from 20000 r / min to 35000 r / min is defined as the speed increase response time T1, and the time required to reduce the fan speed from 35000 r / min to 20000 r / min is the speed. Let the reduced response time be T2. The fan is rotated by a DC motor. In the DC motor, the fall time for decreasing the rotation speed is slower than the rise time for increasing the rotation speed. Therefore, the rotation speed increase response time T1 is shorter than the rotation speed decrease response time T2.

If the valve 250 does not regulate the pressure of the air supplied from the air outlet through the tube 300 to the mask 400, the fan speed will be 35,000 to reduce the pressure when the patient is exhaling air. Even if the pressure is reduced from [r / min] to 20000 [r / min], the pressure drop is slow and the pressure drop takes time because the rotation speed reduction response time T2 is long. Since it takes time for the pressure to drop, the pressure remains when the patient PA is exhaling air, and the air continues to be given more pressure than necessary. For this reason, patient PA may have difficulty breathing.
Therefore, the CPAP system 100 of the embodiment adjusts the pressure of air supplied from the air outlet to the mask 400 via the tube 300 by opening the valve 250 when the patient PA is exhaling air. With this configuration, when the patient PA is exhaling air, the pressure of the air applied to the patient PA can be reduced, so that the patient PA's difficulty in breathing can be improved.
Hereinafter, the CPAP device 200 included in the CPAP system 100 will be described in detail.

FIG. 4 is a diagram showing an example of a CPAP device according to an embodiment of the present invention. As shown in FIG. 4, the CPAP device 200 includes a fan 210, a pressure sensor 220, a motor 230, a motor drive unit 240, a valve 250, a valve drive unit 260, and a case 270.
The fan 210 is built in the case 270, sucks air from the air inlet AI of the case 270, and sends the sucked air to the air outlet AO.
The pressure sensor 220 is built in the case 270 and periodically measures the pressure of the air sent out by the fan 210. The pressure sensor 220 periodically outputs the measurement result of the air pressure to the motor drive unit 240.
The motor 230 is connected to the fan 210 and rotates the fan 210 based on the information indicating the rotation speed output by the motor drive unit 240. An example of the motor 230 is a three-phase induction motor (three-phase motor). Hereinafter, a case where a three-phase induction motor is applied as an example of the motor 230 will be described.

The motor drive unit 240 acquires the measurement result of the air pressure output by the pressure sensor 220. The motor drive unit 240 determines the rotation speed to be set in the motor 230 based on the acquired measurement result of the air pressure. The motor drive unit 240 outputs information indicating the rotation speed to the motor 230 based on the determined rotation speed. Here, the information indicating the rotation speed output by the motor drive unit 240 is also output to the valve drive unit 260. An example of information indicating the number of revolutions output by the motor drive unit 240 is a PWM (Pulse Width Modulation) signal. Hereinafter, the case where the PWM signal is applied as the information indicating the rotation speed will be described.
FIG. 5 is a diagram showing an example of information indicating the rotation speed.
Based on the acquired air pressure measurement result, the motor drive unit 240 increases the duty ratio of the PWM signal when the measurement result of the air pressure decreases due to the patient PA sucking air. By increasing the duty ratio of the PWM signal, the rotation speed of the fan 210 can be increased, so that pressured air can be sent from the nose to the respiratory tract to the patient PA who is inhaling air.
On the other hand, the motor drive unit 240 reduces the duty ratio when the measurement result of the air pressure increases due to the patient PA exhaling air based on the measurement result of the acquired air pressure. By reducing the duty ratio, the rotation speed of the fan 210 can be reduced, so that the pressure of the air supplied to the mask 400 can be reduced for the patient PA exhaling air. FIG. 5 shows an example in which the duty ratio is increased and then decreased. The explanation will be continued by returning to FIG.

The valve drive unit 260 acquires the PWM signal output by the motor drive unit 240. The valve drive unit 260 generates a pulse for driving the valve 250 (hereinafter referred to as “drive pulse”) based on the acquired PWM signal.
Specifically, the valve drive unit 260 synthesizes a three-phase signal for driving the motor 230 that rotates the fan 210 based on the acquired PWM signal. The valve drive unit 260 determines whether the motor 230 is accelerating or decelerating based on the duty ratio of the combined signal obtained by synthesizing the three-phase signals. When the valve drive unit 260 determines that the motor 230 is accelerating based on the determination result of whether the motor 230 is accelerating or decelerating, the pressure is temporarily reduced by the patient PA sucking air. However, since it is assumed that the fan is supplying air to assist the intake air, a pulse for closing the valve 250 (hereinafter referred to as "closed pulse") is generated. In this way, the valve drive unit 260 generates a pulse for closing the valve 250 when the pressure is temporarily reduced by the patient PA sucking air and the fan is supplying air to assist the intake air. Causes the valve 250 to close. With this configuration, it is possible to prevent air from flowing out from the valve 250, so that it is possible to prevent the pressure from dropping.

When the valve drive unit 260 determines that the motor 230 is decelerating based on the determination result of whether the motor 230 is accelerating or decelerating, the pressure is increased by the patient PA exhaling air. Therefore, a pulse for opening the valve 250 (hereinafter referred to as “open pulse”) is generated. In this way, the valve drive unit 260 causes the valve 250 to open by generating a pulse to open the valve 250 when the pressure is increased by the patient PA exhaling air. With this configuration, air can be allowed to flow out from the valve 250, so that the pressure can be reduced.

The valve 250 is built in the case 270 and regulates the pressure of air supplied from the air outlet AO to the mask 400 mounted on the patient PA via a tube 300 connected to the air outlet AO. An example of the valve 250 is a solenoid valve, a linear valve, and a wastegate valve. Specifically, the valve 250 is supplied from the air outlet AO to the mask 400 attached to the patient PA via the tube 300 by opening and closing the valve 250 according to the drive pulse output by the valve drive unit 260. Adjust the pressure of the air.
When the valve 250 acquires the closed pulse output by the valve drive unit 260, the valve 250 closes the valve 250 based on the acquired closed pulse. In this way, by closing the valve 250 based on the closing pulse output by the valve drive unit 260, air does not flow out from the valve 250, so that it is possible to prevent the pressure from dropping. On the other hand, when the valve 250 acquires the open pulse output by the valve drive unit 260, the valve 250 opens the valve 250 based on the acquired open pulse. In this way, the valve 250 opens based on the open pulse output by the valve drive unit 260, so that air flows out from the valve 250, so that the pressure can be reduced.

FIG. 6 is a diagram showing an example of a characteristic diagram showing the response time of the CPAP system according to the embodiment of the present invention. In the example shown in FIG. 6, similarly to the example shown in FIG. 3, by adjusting the fan speed between 20000 r / min and 35000 r / min at a flow rate of 125 [slpm], 0.5 An example of the response time when adjusting the pressure between [kPa] and 2.5 [kPa] is shown.
Compared with FIG. 3, the rotation speed increase response time T1 is about the same, but it can be seen that the rotation speed decrease response time T2 is shortened. This is because, in the present embodiment, the valve drive unit 260 generates an open pulse when it is determined that the motor 230 is decelerating due to the increase in pressure, so that air leaks from the valve 250. This is because the pressure in the CPAP device 200 drops sharply.

The valve drive unit 260 described above will be described in detail.
(Details of valve drive)
FIG. 7 is a block diagram showing a valve drive unit of the CPAP device according to the embodiment of the present invention. The valve drive unit 260 of the CPAP device 200 includes a voltage level conversion unit 261, a synthesis unit 262, a determination unit 263, a comparison unit 264, a generation unit 265, a switch 266, and a voltage level conversion unit 267. The valve drive unit 260 is composed of a voltage level conversion unit 261, a synthesis unit 262, a determination unit 263, a comparison unit 264, a generation unit 265, a switch 266, and a voltage level conversion unit 267. Since the configuration can be simplified, the propagation delay can be reduced. By reducing the propagation delay, the operating speed can be improved, so that the respiratory response of CPAP can be improved. In addition, since the circuit configuration can be simplified, the device can be miniaturized and the power consumption can be reduced due to the effect of reducing the area.

Each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are PWM signals output by the motor drive unit 240, is supplied to the motor 230. Specifically, the U-phase output voltage is supplied to the U-phase coil of the motor 230, the V-phase output voltage is supplied to the V-phase coil of the motor 230, and the W-phase output voltage is supplied to the W-phase coil of the motor 230. Will be supplied. Further, each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are PWM signals output by the motor drive unit 240, is output to the voltage level conversion unit 261 of the valve drive unit 260. To.

The voltage level conversion unit 261 lowers the respective voltage levels of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage output by the motor drive unit 240 to a low voltage such as 3V or 5V. Then, each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage whose voltage level has been lowered is output to the synthesis unit 262. The U-phase output voltage and the V-phase output voltage output by the motor drive unit 240 by stepping down the respective voltage levels of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage. And the output voltage of the W phase can be adjusted so that they can be output to the subsequent stage. Further, by stepping down the respective voltage levels of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, a low withstand voltage circuit can be used for configuration, so that the cost is low. realizable. Hereinafter, as an example, the case where the respective voltage levels of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage are stepped down to 5 V will be described.

The synthesis unit 262 acquires each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are the voltage level output by the voltage level conversion unit 261. The U-phase output voltage, the V-phase output voltage, and the W-phase output voltage are combined. Specifically, the synthesizing unit 262 logically synthesizes each of the U-phase output voltage obtained by stepping down the acquired voltage level, the V-phase output voltage, and the W-phase output voltage to obtain a voltage. The U-phase output voltage whose level has been stepped down, the V-phase output voltage, and the W-phase output voltage are combined. The synthesis unit 262 outputs a synthesis signal obtained by synthesizing each of the U-phase output voltage whose voltage level has been stepped down, the V-phase output voltage, and the W-phase output voltage to the determination unit 263.

FIG. 8 is a diagram showing an example of the operation of the valve drive unit of the CPAP device according to the embodiment of the present invention. In the upper part of FIG. 8, the U-phase output voltage (V (uh)) obtained by stepping down the voltage level output by the voltage level converter 261, the V-phase output voltage (V (vh)), and the W-phase output are shown. It has been shown that a rectangular signal is obtained by combining with the voltage (V (wh)).
Further, in the lower part of FIG. 8, the combined signals are the U-phase output voltage (V (uh)), the V-phase output voltage (V (vh)), and the W-phase output voltage (V (wh)). It is shown that it is represented by the logical sum of. Returning to FIG. 7, the explanation will be continued.

The determination unit 263 acquires the composite signal output by the synthesis unit 262, and determines the rotation speed of the motor 230 based on the duty ratio of the acquired composite signal. Specifically, the determination unit determines that the motor 230 is accelerating when the value obtained by converting the frequency or duty ratio of the combined signal into a voltage is equal to or greater than the threshold value, and converts the frequency or duty ratio of the combined signal into a voltage. When the converted value is less than the threshold value, it is determined that the motor 230 is decelerating. By determining whether the motor 230 is accelerating or decelerating, it is possible to detect whether the state of the patient PA is inhaling or exhaling. When the determination unit 263 determines that the motor 230 is accelerating, it outputs a signal indicating that the motor 230 is accelerating (hereinafter referred to as "acceleration signal") to the comparison unit 264, and determines that the motor 230 is decelerating. When the determination is made, a signal indicating that the vehicle is decelerating (hereinafter referred to as "deceleration signal") is output to the comparison unit 264.

The comparison unit 264 changes the hysteresis width based on the acceleration signal or deceleration signal output by the determination unit 263 and the drive pulse output by the generation unit 265 to reduce noise due to unnecessary acceleration or deceleration of the motor 230. Cancel. The comparison unit 264 cancels the noise and outputs an acceleration signal or a deceleration signal in which the noise is canceled by changing the hysteresis width to the generation unit 265. Specifically, an example of the comparison unit 264 is realized by a hysteresis comparator. By realizing the comparison unit 264 with a hysteresis comparator, it is possible to prevent erroneous detection by changing the hysteresis width of the threshold value in a timely manner with respect to the noise generated by the unnecessary acceleration or deceleration of the motor 230, and also to prevent the hysteresis. By changing the width, various noises of CPAP can be removed.

The generation unit 265 acquires the signal output by the comparison unit 264, and generates a drive pulse based on the acquired signal. Specifically, the generation unit 265 generates a closed pulse when the comparison unit 264 outputs an acceleration signal. The generation unit 265 adjusts the closed pulse width tw1 of the generated closed pulse. On the other hand, the generation unit 265 generates an open pulse when the comparison unit 264 outputs a deceleration signal. The generation unit 265 adjusts the open pulse width tw2 of the generated open pulse. By arbitrarily changing either the closed pulse width tw1 or the open pulse width tw2, adjustment according to the respiration of the patient PA becomes possible in the field. The generation unit 265 outputs the generated closed pulse or open pulse to the switch 266. The open or closed pulse is also used as a control signal to generate a timed threshold hysteresis to cancel the noise generated by the unwanted acceleration or deceleration of the motor.

The switch 266 includes a first terminal to which a closed pulse is input, a second terminal to which an open pulse is input, and a third terminal to output a closed pulse or an open pulse. By switching between the first terminal and the second terminal, the switch 266 outputs one or both of the closed pulse and the open pulse continuously in time from the third terminal. Either the closed pulse or the open pulse output by the switch 266 is output to the voltage level conversion unit 267.
The voltage level conversion unit 267 converts the voltage level of either the closed pulse or the open pulse output from the switch 266 so as to match the input signal for opening / closing the valve 250. The voltage level converter 267 outputs either a closed pulse or an open pulse whose voltage level has been converted to the valve 250.

(Operation of CPAP system)
FIG. 9 is a flowchart showing an example of the operation of the CPAP system according to the embodiment of the present invention. FIG. 9 shows the operation after the CPAP system 100 is started. That is, the operation after the CPAP device 200 rotates the fan 210 is shown.
(Step S1)
The pressure sensor 220 of the CPAP device 200 measures the pressure of the air delivered by the fan 210. The pressure sensor 220 outputs the measurement result of the air pressure to the motor drive unit 240.
(Step S2)
The motor drive unit 240 of the CPAP device 200 acquires the measurement result of the air pressure output by the pressure sensor 220, and determines the rotation speed to be set in the motor 230 based on the acquired air pressure measurement result. The motor drive unit 240 outputs information indicating the rotation speed to the motor 230 and the valve drive unit 260 based on the determined rotation speed. The motor drive unit 240 outputs a PWM signal as information indicating the rotation speed.
The motor 230 acquires a PWM signal output by the motor drive unit 240, and rotates the fan 210 based on the acquired PWM signal.

(Step S3)
The PWM signal output by the motor drive unit 240 is also output to the valve drive unit 260.
The voltage level conversion unit 261 of the valve drive unit 260 acquires the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are PWM signals output by the motor drive unit 240, and the acquired U. The voltage levels of the phase output voltage, the V phase output voltage, and the W phase output voltage are stepped down. The voltage level conversion unit 261 outputs each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage whose voltage level is stepped down to the synthesis unit 262.
(Step S4)
The synthesizing unit 262 acquires each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are the voltage levels output by the voltage level conversion unit 261, and the acquired voltage levels are lowered. The U-phase output voltage, the V-phase output voltage, and the W-phase output voltage are combined. The synthesis unit 262 outputs a synthesis signal obtained by synthesizing each of the U-phase output voltage whose voltage level has been stepped down, the V-phase output voltage, and the W-phase output voltage to the determination unit 263.
(Step S5)
The determination unit 263 acquires the composite signal output by the synthesis unit 262, and determines the rotation speed of the motor 230 based on the duty ratio of the acquired composite signal. The determination unit 263 outputs an acceleration signal to the comparison unit 264 when it determines that the motor 230 is accelerating, and outputs a deceleration signal to the comparison unit 264 when it determines that the motor 230 is decelerating. ..

(Step S6)
The comparison unit 264 cancels the noise due to unnecessary acceleration of the motor 230 by changing the hysteresis width based on the acceleration signal output by the determination unit 263 and the drive pulse output by the generation unit 265. The comparison unit 264 cancels the noise and outputs an acceleration signal in which the noise is canceled by changing the hysteresis width to the generation unit 265.
The generation unit 265 acquires the acceleration signal output by the comparison unit 264, and generates a closed pulse based on the acquired acceleration signal. The generation unit 265 adjusts the pulse width tw1 of the generated closed pulse. The generation unit 265 outputs the generated closed pulse to the switch 266. By switching to the first terminal, the switch 266 outputs the closed pulse output by the generation unit 265 from the third terminal to the voltage level conversion unit 267.
(Step S7)
The voltage level conversion unit 267 converts the voltage level of the closed pulse output by the switch 266 so as to match the input signal for opening and closing the valve 250. The closed pulse whose voltage level has been converted by the voltage level converter 267 is output to the valve 250.
(Step S8)
The valve 250 closes the valve 250 based on the closing pulse output by the voltage level converter 267. By closing the valve 250, air does not flow out of the valve 250, so the pressure is once reduced by the patient inhaling air, and the pressure is increased when the fan is supplying air to assist inspiration. It can be prevented from decreasing.

(Step S9)
The comparison unit 264 cancels the noise due to unnecessary acceleration of the motor 230 by changing the hysteresis width based on the deceleration signal output by the determination unit 263 and the drive pulse output by the generation unit 265. The comparison unit 264 cancels the noise and outputs a deceleration signal in which the noise is canceled by changing the hysteresis width to the generation unit 265.
The generation unit 265 acquires the deceleration signal output by the comparison unit 264, and generates an open pulse based on the acquired deceleration signal. The generation unit 265 adjusts the pulse width tw2 of the generated open pulse. The generation unit 265 outputs the generated open pulse to the switch 266. By switching to the second terminal, the switch 266 outputs the open pulse output by the generation unit 265 from the third terminal to the voltage level conversion unit 267.
(Step S10)
The voltage level conversion unit 267 converts the voltage level of the open pulse output by the switch 266 so as to match the input signal for opening and closing the valve 250. The open pulse whose voltage level is converted by the voltage level conversion unit 267 is output to the valve 250.
(Step S11)
The valve 250 opens the valve 250 based on the open pulse output by the voltage level converter 267.

In the above-described embodiment, the case where the CPAP device 200 is provided with the valve 250 has been described, but the present invention is not limited to this example. For example, it may be provided on the tube 300 or the mask 400. By providing the valve 250 in the CPAP device 200, the valve 250 and the pressure sensor 220 are installed at close positions, so that the time from when the patient starts sucking air until the valve 250 closes and the patient The time from when the valve 250 starts to discharge air until the valve 250 opens can be shortened as compared with the case where the valve 250 is provided at another position.
In the above-described embodiment, when the valve drive unit 260 determines that the motor 230 is accelerating, it generates a closed pulse, closes the valve 250 by the generated closed pulse, and determines that the motor 230 is decelerating. However, the case where an open pulse is generated and the valve 250 is controlled to be opened by the generated open pulse has been described, but the present invention is not limited to this example. For example, when the valve drive unit 260 determines that the motor 230 is accelerating, it generates a closed pulse, and the generated closed pulse causes the valve 250 to be closed more than the previous time, in other words, to be half-opened. Good. Further, for example, when the valve drive unit 260 determines that the motor 230 is decelerating, an open pulse is generated, and the generated open pulse causes the valve 250 to be opened more than the previous time, in other words, to be half-opened. You may. With this configuration, the valve 250 can be gradually closed and opened, so that the inside of the case 270 can be set to an arbitrary pressure.

In the above-described embodiment, the case where the PWM signal which is the information indicating the rotation speed output by the motor drive unit 240 is the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage has been described. , Not limited to this example. For example, the PWM signal, which is information indicating the number of rotations output by the motor drive unit 240, is the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, and the U-phase L. It can also be applied when the output voltage on the side, the output voltage on the V-phase L side, and the output voltage on the W-phase L side.
The PWM signals are the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, the output voltage on the V-phase L side, and W. The case where the output voltage is on the phase L side will be described. In this case, FIG. 1 can be applied to an example of a CPAP system, and FIG. 4 can be applied to an example of a CPAP device.
The motor drive unit 240 outputs a PWM signal as information indicating the rotation speed. The output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, and the V-phase L, which are PWM signals output by the motor drive unit 240. Each of the output voltage on the side and the output voltage on the W phase L side is supplied to the motor 230. Specifically, the output voltage on the U-phase H side and the output voltage on the U-phase L side are supplied to the U-phase coil of the motor 230, and the output voltage on the V-phase H side and the output voltage on the V-phase L side are the motor. It is supplied to the V-phase coil of 230, and the output voltage on the W-phase H side and the output voltage on the W-phase L side are supplied to the W-phase coil of the motor 230. Further, the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, and V, which are PWM signals output by the motor drive unit 240. Each of the output voltage on the phase L side and the output voltage on the W phase L side is output to the voltage level conversion unit 261 of the valve drive unit 260.

The voltage level conversion unit 261 includes the U-phase H-side output voltage, the V-phase H-side output voltage, the W-phase H-side output voltage, and the U-phase L-side output voltage output by the motor drive unit 240. The output voltage on the V-phase L side and the output voltage on the W-phase L side are stepped down to a voltage such as 3V or 5V, and the voltage level is stepped down on the U-phase H side and the V-phase. The output voltage on the H side, the output voltage on the W phase H side, the output voltage on the U phase L side, the output voltage on the V phase L side, and the output voltage on the W phase L side are each sent to the combining unit 262. Output. The output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, the output voltage on the V-phase L side, and the output voltage on the W-phase L side. By stepping down each voltage level with the output voltage, the output voltage on the U-phase H side output by the motor drive unit 240, the output voltage on the V-phase H side, the output voltage on the W-phase H side, and the U The output voltage on the phase L side, the output voltage on the V phase L side, and the output voltage on the W phase L side can be adjusted so that they can be output to the subsequent stage. Further, the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, the output voltage on the V-phase L side, and the W-phase L By stepping down each voltage level with the output voltage on the side, it can be configured by using a low withstand voltage circuit, so that it can be realized at low cost. Hereinafter, as an example, the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, and the output voltage on the V-phase L side. The case where each voltage level with the output voltage on the W phase L side is stepped down to 5V will be continued.

The synthesis unit 262 includes an output voltage on the U-phase H side, which is a step-down voltage level output by the voltage level conversion unit 261, an output voltage on the V-phase H side, an output voltage on the W-phase H side, and a U-phase L side. The output voltage on the U-phase H side and the output voltage on the V-phase H side, which are obtained by acquiring the output voltage, the output voltage on the V-phase L side, and the output voltage on the W-phase L side, and stepping down the acquired voltage level. , The output voltage on the W phase H side, the output voltage on the U phase L side, the output voltage on the V phase L side, and the output voltage on the W phase L side are combined. Specifically, the synthesis unit 262 has the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, and the output on the U-phase L side, with the acquired voltage level stepped down. The output voltage on the U-phase H side and the output voltage on the V-phase H side whose voltage level is stepped down by logically synthesizing each of the voltage, the output voltage on the V-phase L side, and the output voltage on the W-phase L side. The output voltage of the W phase H side, the output voltage of the U phase L side, the output voltage of the V phase L side, and the output voltage of the W phase L side are combined. The synthesis unit 262 includes an output voltage on the U-phase H side whose voltage level has been stepped down, an output voltage on the V-phase H side, an output voltage on the W-phase H side, an output voltage on the U-phase L side, and a V-phase L side. The combined signal obtained by synthesizing each of the output voltage of the W phase L side and the output voltage of the W phase L side is output to the determination unit 263.

FIG. 10 is a diagram showing an example of the operation of the valve drive unit of the CPAP device according to the embodiment of the present invention. In FIG. 10, the output voltage (V (uh)) on the U-phase H side, which is the step-down voltage level output by the voltage level converter 261, the output voltage (V (vh)) on the V-phase H side, and the W-phase are shown. It is shown that the first rectangular signal is obtained by combining the output voltage (V (wh)) on the H side. Further, the output voltage (V (ul)) on the U-phase L side, the output voltage (V (vr)) on the V-phase L side, and the output voltage (V (wl)) on the W-phase L side are combined. This shows that a second rectangular signal is obtained. Further, it is shown that the combined signal is obtained by synthesizing the first rectangular signal and the second rectangular signal.
In addition, the following is shown in the lower part of FIG. The first rectangular signal includes the output voltage (V (uh)) on the U-phase H side, the output voltage (V (vh)) on the V-phase H side, and the output voltage (V (wh)) on the W-phase H side. It is represented by the logical sum of. The second rectangular signal includes the output voltage (V (ul)) on the U-phase L side, the output voltage (V (vr)) on the V-phase L side, and the output voltage (V (wl)) on the W-phase L side. It is represented by the logical sum of. The combined signal is represented by the logical product of the first rectangular signal and the second rectangular signal.

FIG. 11 is a diagram showing the operation of the valve drive unit of the CPAP device according to the embodiment of the present invention. In FIG. 11, the output voltage (V (uh)) on the U-phase H side, the output voltage (V (vh)) on the V-phase H side, and the W-phase are shown in which the voltage level output by the voltage level converter 261 is stepped down. It is shown that the first rectangular signal is obtained by combining the output voltage (V (wh)) on the H side. Further, the output voltage (V (ul)) on the U-phase L side, the output voltage (V (vr)) on the V-phase L side, and the output voltage (V (wl)) on the W-phase L side are combined. This shows that a second rectangular signal is obtained. Further, it is shown that the combined signal is obtained by synthesizing the first rectangular signal and the second rectangular signal.
Further, in the lower part of FIG. 11, the following is shown. The first rectangular signal includes the output voltage (V (uh)) on the U-phase H side, the output voltage (V (vh)) on the V-phase H side, and the output voltage (V (wh)) on the W-phase H side. It is represented by the logical sum of. The second rectangular signal includes the output voltage (V (ul)) on the U-phase L side, the output voltage (V (vr)) on the V-phase L side, and the output voltage (V (wl)) on the W-phase L side. It is represented by the logical sum of. The combined signal is represented by the logical product of the first rectangular signal and the second rectangular signal.

According to the CPAP system 100 of the embodiment, the CPAP system 100 includes a fan 210, a pressure sensor 220, a case 270, a motor drive unit 240, a valve 250, and a valve drive unit 260.
The fan 210 sucks in air and sends it out. The pressure sensor 220 measures the pressure of the air sent out by the fan 210. The case 270 includes a fan 210 and a pressure sensor 220, and has an air inlet AI that allows air sent into the fan 210 to flow in and an air outlet AO that allows air sent out from the fan 210 to flow out. The motor drive unit 240 controls the rotation speed of the motor 230 that rotates the fan 210 by a PWM signal based on the pressure measured by the pressure sensor 220. The valve 250 regulates the pressure of air supplied from the air outlet AO to the mask 400 mounted on the patient PA via the tube 300. The valve drive unit 260 opens and closes the valve 250 based on the PWM signal. The valve drive unit 260 includes a synthesis unit 262 that synthesizes a three-phase signal that drives the motor 230 based on the PWM signal, and the valve drive unit 260 is a composition obtained by synthesizing the three-phase signal by the synthesis unit 262. The valve 250 is opened and closed based on the signal.
When the patient P sucks air, the pressure is temporarily reduced, and when the fan is supplying air to assist the intake air, by closing the valve 250, the air does not flow out from the valve 250, so that the pressure can be increased. .. On the other hand, when the pressure is increased by the patient exhaling air, the pressure can be lowered because the air can be discharged from the valve 250 by opening the valve 250. Therefore, it is possible to improve the difficulty of breathing in patients using CPAP.

Further, the valve drive unit 260 includes a determination unit 263 that determines the rotation speed of the motor based on the duty ratio of the combined signal, and the valve drive unit 260 is based on the result of the determination unit 263 determining the rotation speed of the motor. Then, the valve 250 is opened and closed. The pressure inside the case 270 can be adjusted by determining the rotation speed of the motor based on the duty ratio of the combined signal and opening and closing the valve 250 based on the determination result of the rotation speed of the motor 230. Therefore, it is possible to improve the difficulty of breathing in patients using CPAP.
Further, the determination unit 263 determines that the motor 230 is accelerating when the value obtained by converting the duty ratio of the combined signal into voltage is equal to or greater than the threshold value, and the value obtained by converting the duty ratio of the combined signal into voltage is less than the threshold value. If, it is determined that the motor 230 is decelerating. The pressure in the case 270 can be adjusted by opening and closing the valve 250 based on the determination result of whether the motor 230 is accelerating or decelerating based on the duty ratio of the combined signal. Therefore, it is possible to improve the difficulty of breathing in patients using CPAP.
Further, the valve drive unit 260 includes a generation unit 265 that generates a pulse for driving the valve 250 based on the result of the determination unit 263 determining the rotation speed of the motor 230. Since the valve 250 can be driven by the pulse generated based on the result of determining the rotation speed of the motor 230, the pressure in the case 270 can be adjusted. Therefore, it is possible to improve the difficulty of breathing in patients using CPAP.
Further, the generation unit 265 adjusts the width of the generated pulse. With this configuration, adjustments can be made according to the respiration of the patient PA.
Further, a first voltage level conversion unit (in the embodiment, the voltage level conversion unit 261) that lowers the voltage level of the PWM signal and a second voltage level conversion unit (the embodiment) that raises the voltage level of the pulse generated by the generation unit 265. Then, the voltage level conversion unit 267) is provided. By providing the first voltage level conversion unit, the motor drive voltage can be directly used as the voltage of the PWM signal. By providing a second voltage level converter, an electromagnetic valve can be used for the opening / closing function.

(Modified example of embodiment)
(Overview of CPAP system)
FIG. 1 can be applied to an example of a CPAP system of a modification of the embodiment. However, the CPAP device 200a is provided instead of the CPAP device 200.
The CPAP system 100a includes a CPAP device 200a, a tube 300, and a mask 400.
In the CPAP system 100a of the modified example of the embodiment, the CPAP device 200a controls the opening and closing of the valve 250 based on the measurement result of the air flow rate measured by the flow rate sensor 220a.
Hereinafter, the CPAP device 200a included in the CPAP system 100a will be described in detail.

FIG. 12 is a diagram showing an example of a CPAP device according to a modification of the embodiment of the present invention. As shown in FIG. 12, the CPAP device 200a includes a fan 210, a flow rate sensor 220a, a motor 230, a motor drive unit 240a, a valve 250, a valve drive unit 260, and a case 270.
The flow rate sensor 220a is built in the case 270 and periodically measures the flow rate of the air sent out by the fan 210. The flow rate sensor 220a periodically outputs the measurement result of the air flow rate to the motor drive unit 240a.
The motor 230 is connected to the fan 210 and rotates the fan 210 based on the information indicating the rotation speed output by the motor drive unit 240a.

The motor drive unit 240a acquires the measurement result of the air flow rate output by the flow rate sensor 220a. The motor drive unit 240a determines the rotation speed to be set in the motor 230 based on the acquired measurement result of the air flow rate. The motor drive unit 240a outputs information indicating the rotation speed to the motor 230 and the valve drive unit 260 based on the determined rotation speed. An example of information indicating the rotation speed output by the motor drive unit 240a is a PWM signal.
Based on the acquired measurement result of the air flow rate, the motor drive unit 240a increases the duty ratio of the PWM signal when the measurement result of the air flow rate increases due to the patient sucking air. With this configuration, the rotation speed of the fan 210 can be increased, so that air can be sent from the nose to the respiratory tract for a patient who is inhaling air.
On the other hand, the motor drive unit 240a reduces the duty ratio when the measurement result of the air flow rate decreases due to the patient exhaling air based on the acquired measurement result of the air flow rate. With this configuration, the rotation speed of the fan 210 can be reduced, so that the flow rate of air supplied to the mask 400 can be reduced for the patient who is exhaling air.
FIG. 6 can be applied as an example of a characteristic diagram showing the response time of the modified CPAP system 100a. That is, it can be seen that the rotation speed increase response time T1 is about the same, but the rotation speed decrease response time T2 is shortened. This is because, in this modification, the valve drive unit 260 generates an open pulse when it is determined that the motor 230 is decelerating due to the decrease in the flow rate, so that air leaks from the valve 250. This is because the pressure in the CPAP device 200 drops sharply.

(Operation of CPAP system)
FIG. 13 is a flowchart showing an example of the operation of the CPAP system according to the modification of the embodiment of the present invention. FIG. 13 shows the operation after the CPAP system 100a is started. That is, the operation after the CPAP device 200a rotates the fan 210 is shown.
(Step S1a)
The flow rate sensor 220a of the CPAP device 200a measures the flow rate of the air sent out by the fan 210. The flow rate sensor 220a outputs the measurement result of the air flow rate to the motor drive unit 240a.
(Step S2a)
The motor drive unit 240a of the CPAP device 200a acquires the measurement result of the air flow rate output by the flow rate sensor 220a, and determines the rotation speed to be set in the motor 230 based on the measurement result of the acquired air flow rate. The motor drive unit 240a outputs information indicating the rotation speed to the motor 230 and the valve drive unit 260 based on the determined rotation speed. The motor drive unit 240a outputs a PWM signal as information indicating the rotation speed.
The motor 230 acquires a PWM signal output by the motor drive unit 240a, and rotates the fan 210 based on the acquired PWM signal.

(Step S3a)
The PWM signal output by the motor drive unit 240a is also output to the valve drive unit 260.
The voltage level conversion unit 261 of the valve drive unit 260 acquires the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are PWM signals output by the motor drive unit 240a, and obtains the acquired U. The respective voltage levels of the phase output voltage, the V phase output voltage, and the W phase output voltage are stepped down to a low voltage. The voltage level conversion unit 261 outputs each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage whose voltage level is stepped down to the synthesis unit 262.
(Step S4a)
The synthesis unit 262 acquires each of the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage, which are the voltage level output by the voltage level conversion unit 261. The U-phase output voltage, the V-phase output voltage, and the W-phase output voltage are combined. The synthesis unit 262 outputs a synthesis signal obtained by synthesizing each of the U-phase output voltage whose voltage level has been stepped down, the V-phase output voltage, and the W-phase output voltage to the determination unit 263.
(Step S5a)
The determination unit 263 acquires the composite signal output by the synthesis unit 262, and determines the rotation speed of the motor 230 based on the duty ratio of the acquired composite signal. The determination unit 263 outputs an acceleration signal to the comparison unit 264 when it determines that the motor 230 is accelerating, and outputs a deceleration signal to the comparison unit 264 when it determines that the motor 230 is decelerating. ..

(Step S6a)
The comparison unit 264 cancels the noise due to unnecessary acceleration of the motor 230 by changing the hysteresis width based on the acceleration signal output by the determination unit 263 and the drive pulse output by the generation unit 265. The comparison unit 264 cancels the noise and outputs an acceleration signal in which the noise is canceled by changing the hysteresis width to the generation unit 265.
The generation unit 265 acquires the acceleration signal output by the comparison unit 264, and generates a closed pulse based on the acquired acceleration signal. The generation unit 265 adjusts the pulse width tw1 of the generated closed pulse. The generation unit 265 outputs the generated closed pulse to the switch 266. By switching to the first terminal, the switch 266 outputs the closed pulse output by the generation unit 265 from the third terminal to the voltage level conversion unit 267.
(Step S7a)
The voltage level conversion unit 267 converts the voltage level of the closed pulse output by the switch 266 so as to match the input signal for opening and closing the valve 250. The closed pulse whose voltage level has been converted by the voltage level converter 267 is output to the valve 250.
(Step S8a)
The valve 250 closes the valve 250 based on the closing pulse output by the voltage level converter 267. By closing the valve 250, air does not flow out of the valve 250, so the pressure is once reduced by the patient inhaling air, and the pressure is increased when the fan is supplying air to assist inspiration. It can be prevented from decreasing.

(Step S9a)
The comparison unit 264 cancels the noise due to unnecessary acceleration of the motor 230 by changing the hysteresis width based on the deceleration signal output by the determination unit 263 and the drive pulse output by the generation unit 265. The comparison unit 264 cancels the noise and outputs a deceleration signal in which the noise is canceled by changing the hysteresis width to the generation unit 265.
The generation unit 265 acquires the deceleration signal output by the comparison unit 264, and generates an open pulse based on the acquired deceleration signal. The generation unit 265 adjusts the pulse width tw2 of the generated open pulse. The generation unit 265 outputs the generated open pulse to the switch 266. By switching to the second terminal, the switch 266 outputs the open pulse output by the generation unit 265 from the third terminal to the voltage level conversion unit 267.
(Step S10a)
The voltage level conversion unit 267 converts the voltage level of the open pulse output by the switch 266 so as to match the input signal for opening and closing the valve 250. The open pulse whose voltage level is converted by the voltage level conversion unit 267 is output to the valve 250.
(Step S11a)
The valve 250 opens the valve 250 based on the open pulse output by the voltage level converter 267.

In the above-described modification, the case where the valve 250 is provided in the CPAP device 200a has been described, but the present invention is not limited to this example. For example, it may be provided on the tube 300 or the mask 400. By providing the valve 250 in the CPAP device 200a, the valve 250 and the pressure sensor 220 are installed at close positions, so that the time from when the patient starts sucking air until the valve 250 closes and the patient The time from when the valve 250 starts to discharge air until the valve 250 opens can be shortened as compared with the case where the valve 250 is provided at another position.
In the above-described modification, when the valve drive unit 260 determines that the motor 230 is accelerating, it generates a closed pulse, closes the valve 250 by the generated closed pulse, and determines that the motor 230 is decelerating. However, the case where an open pulse is generated and the valve 250 is controlled to be opened by the generated open pulse has been described, but the present invention is not limited to this example. For example, when the valve drive unit 260 determines that the motor 230 is accelerating, it generates a closed pulse, and the generated closed pulse causes the valve 250 to be closed more than the previous time, in other words, to be half-opened. Good. Further, for example, when the valve drive unit 260 determines that the motor 230 is decelerating, an open pulse is generated, and the generated open pulse causes the valve 250 to be opened more than the previous time, in other words, to be half-opened. You may. With this configuration, the valve 250 can be gradually closed and opened, so that the inside of the case 270 can be set to an arbitrary pressure.

In the above-described modification, the case where the PWM signal, which is information indicating the rotation speed output by the motor drive unit 240a, is the U-phase output voltage, the V-phase output voltage, and the W-phase output voltage has been described. , Not limited to this example. For example, the PWM signal, which is information indicating the number of rotations output by the motor drive unit 240a, is the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, and the U-phase L. It can also be applied when the output voltage on the side, the output voltage on the V-phase L side, and the output voltage on the W-phase L side.
The PWM signals are the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, the output voltage on the V-phase L side, and W. The case where the output voltage is on the phase L side will be described. In this case, FIG. 1 can be applied to an example of a CPAP system, and FIG. 4 can be applied to an example of a CPAP device.
The motor drive unit 240a outputs a PWM signal as information indicating the rotation speed. The output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, and the V-phase L, which are PWM signals output by the motor drive unit 240a. Each of the output voltage on the side and the output voltage on the W phase L side is supplied to the motor 230. Specifically, the output voltage on the U-phase H side and the output voltage on the U-phase L side are supplied to the U-phase coil of the motor 230, and the output voltage on the V-phase H side and the output voltage on the V-phase L side are the motor. It is supplied to the V-phase coil of 230, and the output voltage on the W-phase H side and the output voltage on the W-phase L side are supplied to the W-phase coil of the motor 230. Further, the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, and V, which are PWM signals output by the motor drive unit 240a. Each of the output voltage on the phase L side and the output voltage on the W phase L side is output to the voltage level conversion unit 261 of the valve drive unit 260.

The voltage level conversion unit 261 includes the U-phase H-side output voltage, the V-phase H-side output voltage, the W-phase H-side output voltage, and the U-phase L-side output voltage output by the motor drive unit 240a. The output voltage on the V-phase L side and the output voltage on the W-phase L side are stepped down to a voltage such as 3V or 5V, and the voltage level is stepped down on the U-phase H side and the V-phase. The output voltage on the H side, the output voltage on the W phase H side, the output voltage on the U phase L side, the output voltage on the V phase L side, and the output voltage on the W phase L side are each sent to the combining unit 262. Output. The output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, the output voltage on the V-phase L side, and the output voltage on the W-phase L side. By stepping down each voltage level with the output voltage, the output voltage on the U-phase H side output by the motor drive unit 240a, the output voltage on the V-phase H side, the output voltage on the W-phase H side, and the U The output voltage on the phase L side, the output voltage on the V phase L side, and the output voltage on the W phase L side can be adjusted so that they can be output to the subsequent stage. Further, the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, the output voltage on the V-phase L side, and the W-phase L By stepping down each voltage level with the output voltage on the side, it can be configured by using a low withstand voltage circuit, so that it can be realized at low cost. Hereinafter, as an example, the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, the output voltage on the U-phase L side, and the output voltage on the V-phase L side. The case where each voltage level with the output voltage on the W phase L side is stepped down to 5V will be continued.

The synthesis unit 262 includes an output voltage on the U-phase H side, which is a step-down voltage level output by the voltage level conversion unit 261, an output voltage on the V-phase H side, an output voltage on the W-phase H side, and a U-phase L side. The output voltage on the U-phase H side and the output voltage on the V-phase H side, which are obtained by acquiring the output voltage, the output voltage on the V-phase L side, and the output voltage on the W-phase L side, and stepping down the acquired voltage level. , The output voltage on the W phase H side, the output voltage on the U phase L side, the output voltage on the V phase L side, and the output voltage on the W phase L side are combined. Specifically, the synthesis unit 262 has the output voltage on the U-phase H side, the output voltage on the V-phase H side, the output voltage on the W-phase H side, and the output on the U-phase L side, with the acquired voltage level stepped down. The output voltage on the U-phase H side and the output voltage on the V-phase H side whose voltage level is stepped down by logically synthesizing each of the voltage, the output voltage on the V-phase L side, and the output voltage on the W-phase L side. The output voltage of the W phase H side, the output voltage of the U phase L side, the output voltage of the V phase L side, and the output voltage of the W phase L side are combined. The synthesis unit 262 has a voltage level stepped down on the U-phase H side, an output voltage on the V-phase H side, an output voltage on the W-phase H side, an output voltage on the U-phase L side, and a V-phase L side. The combined signal obtained by synthesizing each of the output voltage of the W phase L side and the output voltage of the W phase L side is output to the determination unit 263.
10 and 11 can be applied to the drawings showing an example of the operation of the valve drive unit 260 of the CPAP device 200a of the modified example of the embodiment of the present invention.

According to the modified CPAP system 100a, the CPAP system 100a includes a fan 210, a flow rate sensor 220a, a case 270, a motor drive 240a, a valve 250, and a valve drive 260. The fan 210 sucks in air and sends it out. The flow rate sensor 220a measures the flow rate of the air sent out by the fan 210. The case 270 includes a fan 210 and a flow rate sensor 220a, and has an air inlet AI for inflowing air sent into the fan 210 and an air outlet AO for letting out air sent out from the fan 210. The motor drive unit 240a controls the rotation speed of the motor 230 that rotates the fan 210 by a PWM signal based on the flow rate measured by the flow rate sensor 220a. The valve 250 regulates the pressure of air supplied from the air outlet AO to the mask 400 mounted on the patient PA via the tube 300. The valve drive unit 260 opens and closes the valve 250 based on the PWM signal. The valve drive unit 260 includes a synthesis unit 262 that synthesizes a three-phase signal that drives the motor 230 based on the PWM signal, and the valve drive unit 260 is a composition obtained by synthesizing the three-phase signal by the synthesis unit 262. The valve 250 is opened and closed based on the signal.
When the flow rate is increased by the patient P sucking air, the pressure can be increased by closing the valve 250 because the air does not flow out from the valve 250. Further, when the flow rate is reduced due to the patient exhaling air, the air can be discharged from the valve 250 by opening the valve 250, so that the pressure can be further reduced. Therefore, it is possible to improve the difficulty of breathing in patients using CPAP.

Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. The embodiments and modifications thereof include, for example, those that can be easily assumed by those skilled in the art, those that are substantially the same, those that have an equal range, and the like.

100, 100a ... CPAP system, 200, 200a ... CPAP device, 210 ... fan, 220 ... pressure sensor, 220a ... flow rate sensor, 230 ... motor, 240, 240a ... motor drive unit, 250 ... valve, 260 ... valve drive unit, 270 ... case, 300 ... tube, 400 ... mask

Claims (7)

A fan that sucks in and sends out air,
A sensor that measures the pressure or flow rate of the air sent out by the fan,
A case in which the fan and the sensor are built in, and having an air inlet for inflowing air sent into the fan and an air outlet for letting out air sent out from the fan.
A motor drive unit that controls the rotation speed of a motor that rotates the fan by a PWM signal based on the pressure or the flow rate measured by the sensor.
A valve that regulates the pressure or flow rate of air supplied from the air outlet to the mask worn on the patient via a tube.
A valve drive unit that opens and closes the valve based on the PWM signal,
With
The valve drive unit includes a synthesizer unit that synthesizes a three-phase signal for driving the motor based on the PWM signal.
The valve drive unit is a CPAP system that opens and closes the valve based on a combined signal obtained by the combined unit synthesizing the three-phase signal. The valve drive unit
A determination unit for determining the rotation speed of the motor based on the duty ratio of the combined signal is provided.
The CPAP system according to claim 1, wherein the valve drive unit opens and closes the valve based on the result of the determination unit determining the rotation speed of the motor. The determination unit determines that the motor is accelerating when the value obtained by converting the duty ratio of the combined signal into voltage is equal to or greater than the threshold value, and the value obtained by converting the duty ratio of the combined signal into voltage is the threshold value. The CPAP system according to claim 2, wherein if it is less than, it is determined that the motor is decelerating. The CPAP system according to claim 2 or 3, wherein the valve drive unit includes a generation unit that generates a pulse for driving the valve based on the result of the determination unit determining the rotation speed of the motor. .. The CPAP system according to claim 4, wherein the generation unit adjusts the width of the generated pulse. A first voltage level converter that steps down the voltage level of the PWM signal,
The CPAP system according to claim 4 or 5, further comprising a second voltage level converter that boosts the voltage level of the pulse generated by the generator. A fan that sucks in and sends out air,
A sensor that measures the pressure or flow rate of the air sent out by the fan,
A case in which the fan and the sensor are built in, and having an air inlet for inflowing air sent into the fan and an air outlet for letting out air sent out from the fan.
A motor drive unit that controls the rotation speed of a motor that rotates the fan by a PWM signal based on the pressure or the flow rate measured by the sensor.
A valve that regulates the pressure or flow rate of air supplied from the air outlet to the mask worn on the patient via a tube.
A valve drive unit that opens and closes the valve based on the PWM signal,
With
The valve drive unit includes a synthesizer unit that synthesizes a three-phase signal for driving the motor based on the PWM signal.
The valve drive unit is a CPAP device that opens and closes the valve based on a combined signal obtained by the combined unit synthesizing the three-phase signal.

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