JP6780711B2 - Fluid control device - Google Patents

Description

The present invention relates to a fluid control device used, for example, for positive airway pressure (PAP).

Conventionally, for the treatment of sleep-related disorders such as obstructive sleep apnea syndrome (OSA), for example, a fluid control device such as a continuous positive airway pressure (CPAP) device (hereinafter referred to as CPAP device) has been used. Used. For example, a CPAP device has a device body with a built-in fan, and supplies gas (for example, air) from the device body to a mask worn on the patient's face at a constant pressure higher than atmospheric pressure.

By the way, if the gas is constantly supplied at a constant pressure, the gas may be supplied at a constant pressure even when exhaling, that is, when exhaling, so that the patient may feel suffocating. In order to reduce the pressure of the fluid, for example, it has been proposed to allow the fan to move by inertia, to brake, and the like (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2011-36699

By the way, the pressure of the above fluid is required to be changed in a short time. However, if the fan is inertially moved, it takes time to reduce the pressure. Further, in the case of braking, there is a risk that the size of the device will be increased due to the braking.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a fluid control device which suppresses upsizing and has good controllability of fluid pressure.

The fluid control device that solves the above-mentioned problems is a fluid control device used for positive airway pressure, and accommodates a fan, a drive unit that rotationally drives the fan, and the fan, and by rotationally driving the fan. A housing having an inflow port for flowing a fluid and a discharge port for discharging the fluid by rotationally driving the fan, a communication passage for communicating the discharge port with the nasal cavity or the oral cavity, and the communication passage or the housing. A detection unit that is arranged and can detect the flow velocity or flow rate of the fluid, and a pressure measuring unit that is arranged in the communication passage or the housing and outputs a measured pressure value that measures the pressure in the communication passage or the housing. To the deviation between the pressure command value and the measured pressure value, the first pressure control unit that generates the first speed command related to the rotation speed of the fan based on a predetermined pressure command value determined in advance. Based on the second pressure control unit that generates the second speed command related to the rotation speed of the fan, and the drive command for the drive unit based on the first speed command and the second speed command. When the drive command generation unit, the current supply unit that supplies the drive current to the drive unit based on the drive command value, and the detection unit detect a flow rate or flow velocity of the fluid lower than a predetermined value, the first The switching control unit includes a switching control unit that invalidates the pressure control unit 2 and a speed measuring unit that measures the rotation speed of the fan, and the switching control unit is a fluid whose detection unit is lower than the predetermined value. After detecting the flow rate or the flow velocity, it is determined that the pressure at the time of expiration is reached when the rotation speed of the fan is equal to the rotation speed of the fan according to the drive command, and the second pressure control unit is made effective .

According to this configuration, the first pressure control unit generates the first speed command based on the pressure command value. The second pressure control unit generates a second speed command based on the deviation between the pressure command value and the measured pressure value. A fluid of pressure is discharged by a fan driven based on the first velocity command and the second velocity command. Therefore, the first pressure control unit performs pressure control by feedforward based on the pressure command value, and the second pressure control unit performs pressure control by feeding back the pressure of the fluid with respect to the pressure command value. Therefore, by disabling the second pressure control unit when a fluid flow rate or flow velocity lower than a predetermined value is detected, the influence of the delay due to the feedback is eliminated, and the pressure feed forward control by the first pressure control unit is eliminated. Only by changing the pressure of the fluid in a short time, the controllability of the pressure of the fluid is good. Further, since a mechanism such as a brake is not required to change the rotation speed of the fan, the increase in size of the device is suppressed. Further, only the first pressure control unit changes the rotation speed of the fan in a short time until the measured rotation speed of the fan matches the rotation speed of the fan according to the drive command, and the pressure of the fluid by the fan is changed. .. Then, when the measured rotation speed of the fan becomes equal to the rotation speed of the fan according to the drive command, it is determined that the pressure at the time of intake has been reached, and the pressure feedback control works by enabling the second pressure control unit. , Stable pressure fluid is discharged.

In the above fluid control device, it is preferable that the detection unit sets the pressure command value to a value lower than the reference pressure command value when the detection unit detects the flow rate or flow velocity of the fluid lower than the predetermined value.

According to this configuration, the drive command is generated only by the pressure feedforward control by the first pressure control unit, and the pressure of the fluid is changed in a short time. Then, a fluid having a pressure corresponding to the respiratory state is discharged.

The fluid control device that solves the above problems is a fluid control device used for positive airway pressure, and accommodates a fan, a drive unit that rotationally drives the fan, and the fan, and by rotationally driving the fan. A housing having an inflow port for flowing a fluid and a discharge port for discharging the fluid by rotationally driving the fan, a communication passage for communicating the discharge port with the nasal cavity or the oral cavity, and the communication passage or the housing. A detection unit that is arranged and can detect whether the flow rate or flow velocity of the fluid is higher or lower than a predetermined value, and a measured pressure value that is arranged in the communication passage or the housing and measures the pressure of the fluid is output. A pressure measuring unit, a first pressure control unit that generates a first speed command related to the rotation speed of the fan based on a predetermined predetermined pressure command value, the pressure command value, and the measured pressure value. A second pressure control unit that generates a second speed command related to the rotation speed of the fan based on the deviation of the above, and a drive for the drive unit based on the first speed command and the second speed command. A drive command generation unit that generates a command, a current supply unit that supplies a drive current to the drive unit based on the drive command value, and the detection unit detect a flow rate or flow velocity of the fluid higher than the predetermined value. In some cases, the switching control unit has a switching control unit that invalidates the second pressure control unit and a speed measuring unit that measures the rotation speed of the fan, and the switching control unit has a detection unit higher than the predetermined value. After detecting the flow rate or flow velocity of the fluid, it is determined that the pressure at the time of intake is reached when the rotation speed of the fan is equal to the rotation speed of the fan according to the drive command, and the second pressure control unit is effective. To do .

According to this configuration, the first pressure control unit generates the first speed command based on the pressure command value. Therefore, this first pressure control unit performs speed control based on the pressure command value. The second pressure control unit generates a second speed command based on the deviation between the pressure command value and the measured pressure value. Therefore, this second pressure control unit performs speed control by feeding back the pressure of the fluid. Therefore, by disabling the second pressure control unit when a fluid flow rate or flow velocity higher than a predetermined value is detected, the influence of the delay due to the feedback is eliminated, and the pressure feed forward control by the first pressure control unit is eliminated. The pressure of the fluid is changed in a short time, and the controllability of the pressure of the fluid is good. Further, since a mechanism such as a brake is not required to change the rotation speed of the fan, the increase in size of the device is suppressed. Further, the first pressure control unit changes the rotation speed of the fan in a short time until the measured rotation speed of the fan matches the rotation speed of the fan according to the drive command, and the pressure of the fluid by the fan is changed. Then, after the measured rotation speed of the fan becomes equal to the rotation speed of the fan according to the drive command, the second pressure control unit is effective, and the pressure feedback control and the first pressure control by the second pressure control unit are effective. By the pressure feed forward control by the unit, the pressure of the fluid becomes stable at the pressure command value as the target value.

In the above fluid control device, when the detection unit detects a flow rate or flow velocity of the fluid higher than the predetermined value, it is preferable to set the pressure command value as a reference pressure command value which is a pressure at the time of intake.

According to this configuration, the drive command is generated only by the pressure feedforward control by the first pressure control unit, and the pressure of the fluid is changed in a short time. Then, the fluid having the reference pressure value is discharged in the intake air.

In the above-mentioned fluid control device, it is preferable that the detection unit detects the flow rate or the flow velocity of the fluid higher than the predetermined value to detect the switching from the exhalation to the inspiration.
According to this configuration, it is possible to detect the switch from exhalation to inspiration based on the flow rate or flow velocity of the fluid in the communication passage or the housing and a predetermined value.

In the above fluid control device, the first pressure control unit amplifies the first conversion unit that converts the pressure command value into a speed command and the speed command converted by the first conversion unit. It has a first amplification unit that outputs the first speed command, and the second pressure control unit includes a calculation unit that calculates a deviation pressure value that is a deviation between the pressure command value and the measured pressure. , A second conversion unit that converts the deviation pressure value into a speed command, and a second amplification unit that amplifies the speed command converted by the second conversion unit and outputs the second speed command. The switching control unit has the amplification factor β of the second amplification unit set to “1” to enable the second pressure control unit, and the amplification factor β set to “0” to enable the second pressure. When the control unit is disabled and the second pressure control unit is disabled, the amplification factor α of the first amplification unit is set to 1, and when the second pressure control unit is enabled, the first It is preferable that the amplification factor α of the amplification unit is a value in the range of 1> α> 0.

According to this configuration, the validity and invalidity of the second pressure control unit can be easily set by changing the amplification factor β of the second amplification unit included in the second pressure control unit. Then, when the second pressure control unit is enabled, the amplification factor α of the first amplification unit included in the first pressure control unit is set in the range of 1> α> 0. The larger the amplification factor α, the larger the ratio of pressure feedforward control by the first pressure control unit, and the better the responsiveness of pressure control, but the more easily affected by disturbance. Therefore, by setting the amplification factor α to a value in consideration of the responsiveness and the influence of the disturbance, it is possible to perform pressure control having good responsiveness and being less susceptible to the influence of the disturbance.

According to the fluid control device of the present invention, it is possible to suppress the increase in size and control the pressure of the fluid in a short time.

(A) is a side sectional view of the fluid control device, and (b) is a plan sectional view of the fluid control device. The schematic diagram which shows the use state of a fluid control device. A block diagram showing an electrical configuration of a fluid control device. The block diagram which shows the schematic structure of the control part. A waveform diagram showing the determination of exhalation and inspiration. A waveform diagram showing pressure control of a fluid. A waveform diagram showing the determination of different exhalation and inspiration. A waveform diagram showing pressure control of another fluid.

Hereinafter, each form will be described.
In addition, the attached drawings may show the components in an enlarged manner for easy understanding. The dimensional ratios of the components may differ from the actual ones or those in another drawing. Further, in the cross-sectional view, hatching of some components may be omitted for easy understanding.

As shown in FIG. 2, the fluid control device 10 is used, for example, as a positive airway pressure (PAP) device. The fluid control device 10 is connected to the mask 62 via a tube 61. The mask 62 is worn on the face of the patient 63. The fluid control device 10 supplies the patient 63 with a gas (for example, air) of a desired pressure via the tube 61 and the mask 62. Further, the fluid control device 10 determines the state of the patient 63 (for example, at the time of exhalation) and controls the pressure of the gas supplied to the patient 63 according to the state of the patient.

The fluid control device 10 includes a housing 11, a display unit 12 arranged on the upper surface of the housing 11, and an operation unit 13. The fluid control device 10 displays various information including set values on the display unit 12. Further, the fluid control device 10 sets various information including set values based on the operation of the operation unit 13.

The fluid control device 10 estimates the exhalation timing of the patient 63 wearing the mask 62. Then, the pressure value of the supplied gas is controlled at the estimated exhalation timing. For example, the fluid control device 10 supplies gas at a reference pressure value. The reference pressure value is, for example, a pressure value at the time of inspiration specified by a doctor, for example, 1000 [Pa]. Then, the fluid control device 10 changes the pressure of the supplied gas to the exhalation pressure value at the estimated exhalation timing. The expiratory pressure value is, for example, 700 [Pa]. That is, the fluid control device 10 alternately controls the pressure of the gas supplied according to the state (expiration, inspiration) of the patient 63 to the reference pressure value and the expiration pressure value. When the patient 63 is in the exhaled state, the pressure of the supplied gas is reduced to reduce the suffocation in the patient 63.

As shown in FIGS. 1A and 1B, the fluid control device 10 includes a housing 11, a fan unit 20 and a control unit 30 built in the housing 11. The housing 11 has an inflow port 14 for sucking gas and a discharge port 15 for discharging the sucked gas. The tube 61 shown in FIG. 2 is connected to the discharge port 15. The inside of the housing 11 has a blower chamber 17 and a control chamber 18 partitioned by an erected partition wall 16.

As shown in FIG. 1B, a fan unit 20 is arranged in the blower chamber 17. The fan unit 20 has a fan case 21, a fan 22 housed in the fan case 21, and a motor 23 as a drive source for driving the fan 22.

The fan case 21 has a suction port 21a that opens downward and a discharge path 21b that projects to the side surface. The discharge path 21b of the fan case 21 is inserted into the discharge port 15 of the housing 11. The motor 23 is attached to the upper surface of the fan case 21, and the rotating shaft 23a of the motor 23 is inserted into the fan case 21. The fan 22 is attached to the rotating shaft 23a of the motor 23.

The fan 22 is, for example, a centrifugal fan. When the fan 22 is rotationally driven by the motor 23, gas is taken into the air chamber 17 from the inflow port 14 as shown by an arrow in FIG. 1 (a). Further, as shown by an arrow, the gas is sucked from the air vent chamber 17 into the fan case 21 through the suction port 21a. Then, the gas inside the fan case 21 is discharged from the discharge path 21b. The discharged gas is sent from the discharge port 15 of the housing 11 to the patient 63 via the tube 61 and the mask 62 shown in FIG.

A control unit 30 is arranged in the control chamber 18. The control unit 30 includes, for example, a circuit board and a plurality of electronic components mounted on the circuit board. The control unit 30 rotates and drives the fan 22 based on the detection results of various sensors described later. In addition, the control unit 30 estimates the state of the patient 63 (for example, exhalation timing) based on the detection results of various sensors. Then, the control unit 30 controls the pressure of the gas supplied from the discharge path 21b to the patient 63 based on the estimated state of the patient 63.

FIG. 3 shows the electrical configuration of the fluid control device 10.
As shown in FIG. 3, the fluid control device 10 includes a display unit 12, an operation unit 13, a motor 23, a control unit 30, a pressure sensor 31, a flow rate sensor 32, a motor amplifier 33, and a hall sensor 34.

The pressure sensor 31 is provided in the discharge path 21b or the like shown in FIG. 1A, detects the pressure inside the fan case 21, and outputs a pressure detection signal.
The flow rate sensor 32 is provided, for example, in the discharge path 21b shown in FIG. The flow rate sensor 32 measures the flow rate of the fluid flowing through the flow rate sensor 32 (passing through the flow rate sensor 32).

The Hall sensor 34 is provided to measure the rotation speed (actual rotation speed) of the motor 23. The Hall sensor 34 is provided in the motor 23 and outputs a signal corresponding to the rotation of the motor 23. The motor amplifier 33 transmits the output signal of the hall sensor 34 to the control unit 30, and the control unit 30 obtains information on the rotation speed of the motor 23. That is, the control unit 30, the motor amplifier 33, and the hall sensor 34 function as speed measuring units for measuring the rotational speed of the motor 23. Then, the control unit 30 controls the rotation speed of the motor 23, that is, the rotation speed of the fan 22 so that the gas is discharged at a desired pressure.

Various setting values are stored in the control unit 30. The set value includes a reference pressure value, a decompression amount, and a flow rate determination value.
The control unit 30 determines the rotation speed of the motor 23 based on the actual pressure value detected by the pressure sensor 31 and the reference pressure command included in the set value. Gas is discharged from the fluid control device 10 by the rotation of the motor 23. The control unit 30 calculates the pressure command value based on the reference pressure command and the decompression amount. The control unit 30 controls the pressure of the gas discharged by the fluid control device 10 based on the difference between the pressure command value and the actual pressure value.

The control unit 30 detects the respiratory state (expiration, inspiration) of the patient 63 based on the measurement result (gas flow rate) of the flow rate sensor 32. For example, when the patient 63 is in the inspiratory state, gas is supplied from the fluid control device 10 to the patient 63 via the tube 61 and the mask 62 shown in FIG. At this time, the flow rate sensor 32 of the present embodiment is configured to output, for example, a positive measured value. On the other hand, when the patient 63 is in the exhaled state, gas flows toward the fluid control device 10 via the mask 62 and the tube 61 shown in FIG. At this time, the flow rate sensor 32 of the present embodiment is configured to output, for example, a negative measured value. Further, the control unit 30 may be separately added with a function of controlling the pressure of the gas discharged from the fluid control device 10 by using the measured flow rate.

As shown in FIG. 5, the measurement result of the flow rate sensor 32, that is, the flow rate of the gas in the tube 61 repeats a positive value and a negative value alternately. Therefore, it can be determined that the patient 63 is in the inspiratory state when the measurement result (flow rate value) of the flow rate sensor 32 is positive, and the patient 63 is in the exhaled state when the measurement result (flow rate value) is negative.

The control unit 30 changes the above-mentioned decompression amount based on the respiratory state of the patient 63. That is, the control unit 30 changes the pressure command value based on the respiratory state of the patient 63. For example, the control unit 30 sets the value obtained by adding the decompression amount to the reference pressure command as the pressure command value when the patient 63 is in the exhaled state. The amount of decompression in this case is set according to the patient 63. As a result, the pressure of the gas supplied to the patient 63 is lowered. Further, the control unit 30 sets the pressure command value equal to the reference pressure command, that is, the decompression amount is set to "0" when the patient is in the inspiratory state. As a result, the gas of the reference pressure is supplied to the patient 63.

FIG. 4 shows a partial block diagram of the control unit 30, and shows a control block related to driving the motor 23 (denoted as “M” in the figure) and the fan 22.
The control unit 30 includes a first pressure control unit 41, a second pressure control unit 42, a calculation unit 43, a low-pass filter (denoted as “LPF” in the figure) 44, a calculation unit 45, and a motor amplifier (“AMP” in the figure). 33, and a switching control unit 47.

A reference pressure command value P0 is supplied to the calculation unit 43 as a command value (set value). Further, the calculation unit 43 is supplied with a decompression amount Pc according to the determination result of the switching control unit 47. The calculation unit 43 subtracts the decompression amount Pc from the reference pressure command value P0, that is, calculates the deviation between the reference pressure command value P0 and the decompression amount Pc, and outputs the calculation result as the pressure command value P1. The pressure command value P1 is supplied to the first pressure control unit 41 and the second pressure control unit 42.

The first pressure control unit 41 has a conversion unit 41a and an amplification unit 41b. The pressure command value P1 is supplied to the conversion unit 41a. The conversion unit 41a outputs the speed command S1 corresponding to the pressure command value P1 to the amplification unit 41b. The speed command S1 is a speed command for driving the motor 23, and is a rotation speed command for the motor 23. The speed command S1 is a speed command (rotation speed command) of the fan 22 that is rotationally driven by the motor 23.

An amplification factor α is set in the amplification unit 41b. The value of the amplification factor α is controlled by the switching control unit 47. The amplification unit 41b outputs the result (= S1 × α) of multiplying the speed command S1 by the amplification factor α as the first speed command B1. For example, when the amplification factor α is set to “1”, the amplification unit 41b outputs an input command, that is, a first speed command B1 having a value equal to the speed command S1. The first speed command B1 output from the amplification unit 41b is supplied to the calculation unit 45.

The amplification factor α is set in the range of 1> α> 0. The larger the amplification factor α, the larger the ratio of pressure feedforward control by the first pressure control unit 41, and the better the responsiveness of the pressure control, while being more susceptible to disturbance. Therefore, the amplification factor α is preferably set to a value in consideration of the responsiveness and the influence of disturbance. By setting the value considered in this way to the amplification factor α, it is possible to control the pressure with good responsiveness and being less susceptible to disturbance.

The second pressure control unit 42 has a calculation unit 42a, a conversion unit 42b, and an amplification unit 42c. The pressure command value P1 described above is supplied to the calculation unit 42a. The measured pressure value Pf output from the low-pass filter 44 is supplied to the calculation unit 42a. The pressure detection value Pr detected by the pressure sensor 31 is supplied to the low-pass filter 44. The low-pass filter 44 is a low-pass filter having a predetermined time constant (for example, 2 s). The low-pass filter 44 removes high-frequency noise of the pressure detection value Pr and stabilizes the feedback loop.

The calculation unit 42a subtracts the measured pressure value Pf from the pressure command value P1, that is, calculates the deviation between the pressure command value P1 and the measured pressure value Pf, and outputs the calculated result as the pressure deviation value P2 to the conversion unit 42b.

The conversion unit 42b outputs the speed command S2 corresponding to the pressure deviation value P2 to the amplification unit 42c. For example, a PI controller can be used for the conversion unit 42b. The speed command S2 is a speed command for driving the motor 23, and is a rotation speed command for the motor 23. The speed command S2 is a speed command (rotation speed command) of the fan 22 that is rotationally driven by the motor 23. The speed command S2 corresponds to the pressure deviation value P2, that is, corresponds to the deviation between the pressure command value P1 and the measured pressure value Pf.

The amplification factor β is set in the amplification unit 42c. The value of the amplification factor β is controlled by the switching control unit 47. The amplification unit 42c outputs the result (= S2 × β) obtained by multiplying the speed command S2 by the amplification factor β as the second speed command B2. For example, when the amplification factor β is set to “1”, the amplification unit 42c outputs an input command, that is, a second speed command B2 equal to the speed command S2. Further, when the amplification factor β is set to “0”, the amplification unit 42c outputs a second speed command B2 having a value of “0”. That is, the second speed command B2 becomes invalid. The second speed command B2 output from the amplification unit 42c is supplied to the calculation unit 45.

The calculation unit 45 adds the speed command S2 to the speed command S1 and outputs the addition result as the drive command Vm to the motor amplifier 33. This drive command Vm is a speed command (rotation speed command) of the fan 22 that is rotationally driven by the motor 23.

The motor amplifier 33 supplies the drive current according to the drive command Vm to the motor 23. The motor 23 rotates according to the supplied drive current. Therefore, the motor 23 rotates at a rotation speed corresponding to the drive command Vm.

That is, the first pressure control unit 41 generates the first speed command B1 according to the pressure command value P1. The motor 23 is driven in response to the first speed command B1. That is, the first pressure control unit 41 performs feedforward control for driving the motor 23 by a speed command corresponding to the pressure command value P1.

The second pressure control unit 42 calculates the deviation between the pressure command value P1 and the measured pressure value Pf, and generates the second speed command B2 based on the calculated pressure deviation value P2. The motor 23 is driven in response to the second speed command B2. The measured pressure value Pf is a value corresponding to the drive of the motor 23. That is, the second pressure control unit 42 generates the second speed command B2 so that the measured pressure value Pf is equal to the pressure command value P1 based on the measured pressure value Pf, and drives the motor 23. Perform feedback control.

The switching control unit 47 inputs the measured flow rate value Fr, which is the measurement result of the flow rate sensor 32. The switching control unit 47 determines the respiratory state of the patient 63 based on the measured flow rate value Fr. Further, the switching control unit 47 inputs the drive command Vm and the rotation speed Vr corresponding to the output signal of the hall sensor 34 shown in FIG. In the example of FIG. 4, the drive command Vm and the rotation speed Vr are input to the switching control unit 47, but the deviation between the drive command Vm and the rotation speed Vr may be input to the switching control unit 47. Then, the switching control unit 47 sets the decompression amount Pc and the amplification factors α and β of the amplification units 41b and 42c based on the determined respiratory state of the patient 63, the drive command Vm, and the rotation speed Vr.

For example, when the intake state (measured flow rate value Fr is a positive value), the decompression amount Pc is set to a value that does not decompress (for example, "0"). On the other hand, when the exhaled state (measured flow rate value Fr is a negative value), the decompression amount Pc is set to a value (for example, "300") to reduce the pressure. Further, when the deviation between the rotation speed Vr and the drive command Vm is within a predetermined range, the amplification factor α of the amplification unit 41b is set to “0.9”, and the amplification factor β of the amplification unit 42c is set to “1”. On the other hand, when the deviation between the rotation speed Vr and the drive command Vm exceeds a predetermined range, the amplification factor α of the amplification unit 41b is set to “1”, and the amplification factor β of the amplification unit 42c is set to “0”.

Next, the operation of the fluid control device 10 will be described.
FIG. 6 shows the change in the measured pressure value Pf. In FIG. 6, the horizontal axis is time.
For example, patient 63 shown in FIG. 2 is in an inspiratory state. At this time, the flow rate sensor 32 shown in FIG. 4 outputs a positive measured flow rate value Fr. Therefore, the switching control unit 47 sets the decompression amount Pc to a value that does not reduce the pressure (for example, “0”), sets the amplification factor α of the amplification unit 41b to “0.9”, and sets the amplification factor β of the amplification unit 42c. Let it be "1".

Then, the first pressure control unit 41 of the control unit 30 is the first value obtained by multiplying the speed command S1 corresponding to the pressure command value P1 equal to the reference pressure command value P0 by the amplification factor α (= 0.9). Generate speed command B1. The second pressure control unit 42 applies an amplification factor β (= 1) to the speed command S2 according to the deviation (pressure deviation value P2) between the pressure command value P1 equal to the reference pressure command value P0 and the measured pressure value Pf. Generate a second speed command B2 with the multiplied value. A speed command (drive command Vm) is generated by summing the first speed command B1 and the second speed command B2, and the motor 23 is passed through the motor amplifier 33 according to the deviation between the drive command Vm and the rotation speed Vr. To drive. As a result, as shown in FIG. 6, the pressure of the fluid, that is, the measured pressure value Pf becomes stable at the level LC (the level of the reference pressure command value P0).

By setting the amplification factor α to “0.9” in the first pressure control unit 41, the first pressure control unit 41 has a value smaller than the speed command corresponding to the pressure command value P1, that is, slower. Generate the first speed command B1. Then, the pressure is fed back to the first speed command B1, that is, the second speed generated by the deviation between the measured pressure value Pf (actual pressure value Pr) and the pressure command value P1 (pressure deviation value P2). Command B2 is added to make the drive command Vm for the motor 23. As a result, the pressure of the fluid can be quickly made to follow and stabilize the pressure command value P1 which is the target value.

Next, the patient 63 shown in FIG. 2 is in the exhaled state. At this time, the flow rate sensor 32 shown in FIG. 4 outputs a measured flow rate value Fr (a negative value measured flow rate value Fr) corresponding to the switching from inspiration to exhalation. The switching control unit 47 sets the decompression amount Pc to a value (for example, “300”) based on the measured flow rate value Fr. Further, the switching control unit 47 sets the amplification factor α of the amplification unit 41b to “1” and the amplification factor β of the amplification unit 42c to “0”.

Then, since the amplification factor β of the second pressure control unit 42 of the control unit 30 is “0”, the second speed command B2 is “0”, that is, invalid. The first pressure control unit 41 generates a first speed command B1 equal to the speed command S1 corresponding to the pressure command value P1. Further, a drive command Vm having a value equal to that of the first speed command B1 is generated, and the motor 23 is driven according to the drive command Vm. Then, the rotation speed of the fan 22 rapidly decreases to a speed corresponding to the drive command Vm. As a result, as shown in FIG. 6, the pressure of the fluid, that is, the measured pressure value Pf, drops to the reduced level LE in a short time.

When the rotation speed of the fan 22 decreases and becomes equal to the drive command Vm (first speed command B1), the switching control unit 47 sets the amplification factor α of the amplification unit 41b to “0.9” and amplifies the amplification unit 42c. Let the rate β be “1”. As a result, the second pressure control unit 42 becomes effective. Then, as described above, the first pressure control unit 41 and the second pressure control unit 42 control the motor 23 so that the measured pressure value Pf is equal to the pressure command value P1. As a result, as shown in FIG. 6, the pressure of the fluid, that is, the measured pressure value Pf is stably maintained at the level LE.

Next, the patient 63 shown in FIG. 2 is in an inspiratory state. At this time, the flow rate sensor 32 shown in FIG. 4 outputs a measured flow rate value Fr (a positive value measured flow rate value Fr) according to the switching from exhalation to inspiration. The switching control unit 47 sets the decompression amount Pc to a value (= 0) that does not depressurize, based on the measured flow rate value Fr. Further, the switching control unit 47 sets the amplification factor α of the amplification unit 41b to “1” and the amplification factor β of the amplification unit 42c to “0”.

Then, since the amplification factor β of the second pressure control unit 42 of the control unit 30 is “0”, the second speed command B2 is “0”, that is, invalid. The first pressure control unit 41 generates a first speed command B1 equal to the speed command S1 corresponding to the pressure command value P1. Further, a drive command Vm having a value equal to that of the first speed command B1 is generated, and the motor 23 is driven according to the drive command Vm. Then, the rotation speed of the fan 22 rapidly increases to a speed corresponding to the drive command Vm. As a result, as shown in FIG. 6, the pressure of the fluid, that is, the measured pressure value Pf rises to a predetermined level LC in a short time.

When the rotation speed of the fan 22 increases and becomes equal to the drive command Vm (first speed command B1), the switching control unit 47 sets the amplification factor α of the amplification unit 41b to “0.9” and amplifies the amplification unit 42c. Let the rate β be “1”. As a result, the second pressure control unit 42 becomes effective. Then, as described above, the first pressure control unit 41 and the second pressure control unit 42 control the motor 23 so that the measured pressure value Pf is equal to the pressure command value P1. As a result, as shown in FIG. 6, the pressure of the fluid, that is, the measured pressure value Pf is stably maintained at the level LC.

As described above, according to the present embodiment, the following effects are obtained.
(1) The fluid control device 10 includes a fan 22, a motor 23 as a drive unit for driving the fan 22, and a control unit 30 for controlling the motor 23. Further, the fluid control device 10 has an inflow port 14 into which the fluid flows in, and a discharge port 15 (discharge path 21b) for discharging the fluid by rotationally driving the fan 22. The control unit 30 has a first pressure control unit 41 and a second pressure control unit 42. The first pressure control unit 41 generates the first speed command B1 based on the pressure command value P1. Therefore, the first pressure control unit 41 controls the speed according to the pressure command value P1. The second pressure control unit 42 generates the second speed command B2 based on the deviation between the pressure command value P1 and the measured pressure value Pf. Therefore, the second pressure control unit 42 performs speed control by feeding back the pressure of the fluid.

Therefore, by disabling the second pressure control unit 42 when the switch from inspiration to exhalation is detected, the influence of the delay due to feedback is eliminated, and the fluid up to the pressure command value P1 by the first pressure control unit 41. Pressure is changed in a short time. Similarly, by disabling the second pressure control unit 42 when switching from exhalation to inspiration is detected, the influence of the delay due to feedback is eliminated, and the pressure of the fluid up to the pressure command value by the first pressure control unit. Is changed in a short time. That is, the fluid control device 10 has good controllability of the fluid pressure. Further, since the fluid control device 10 of the present embodiment does not require a mechanism such as a brake for changing (decreasing) the rotation speed of the fan 22, it is possible to suppress an increase in the size of the device.

(2) When the rotation speed Vr becomes equal to the drive command Vm, the switching control unit 47 sets the amplification factor α of the amplification unit 41b to “0.9” and the amplification factor β of the amplification unit 42c to “1”. The amplification factor β (= 1) makes the second pressure control unit 42 effective. Then, the first pressure control unit 41 and the second pressure control unit 42 control the motor 23 so that the measured pressure value Pf is equal to the pressure command value P1. As a result, the pressure of the fluid, that is, the measured pressure value Pf can be stably maintained at the reduced level LE.

(3) The second pressure control unit 42 has a conversion unit 42b that converts the pressure command value P1 into the speed command S2, and an amplification unit 42c that amplifies the speed command S2 and outputs the second speed command B2. ing. The switching control unit 47 changes the amplification factor β of the amplification unit 42c. By setting the amplification factor β to “0”, the second speed command B2 becomes “0”. In this way, the validity and invalidity of the second pressure control unit 42 can be easily controlled by the amplification factor β.

(4) When the second pressure control unit 42 was enabled, the amplification factor α in the first pressure control unit 41 was set to “0.9”. As a result, the first pressure control unit 41 generates a value smaller than the speed command corresponding to the pressure command value P1, that is, a slower first speed command B1. Then, the pressure is fed back to the first speed command B1, that is, the second speed generated by the deviation between the measured pressure value Pf (actual pressure value Pr) and the pressure command value P1 (pressure deviation value P2). Command B2 is added to make the drive command Vm for the motor 23. As a result, the pressure of the fluid can be quickly made to follow and stabilize the pressure command value P1 which is the target value.

In addition, each of the above-mentioned embodiments may be carried out in the following embodiments.
-In the above embodiment, whether the measured flow rate value Fr is positive or negative is detected as inspiration or exhalation, and switching from inspiration to exhalation and switching from exhalation to inspiration are detected. On the other hand, a threshold value for detection may be set as appropriate.

As shown in FIG. 7, threshold values T1 and T2 may be set and detection may be performed based on those threshold values T1 and T2. For example, when the measured flow rate value Fr falls below the threshold value T1 larger than “0”, the switch from inspiration to expiration may be detected. Further, when the measured flow rate value Fr rises above the threshold value T2 smaller than "0", the switch from exhalation to inspiration may be detected.

-The validity and invalidity of the second pressure control unit 42 may be appropriately changed with respect to the above embodiment.
As shown in FIG. 8, it may be invalidated until the measured pressure value Pf reaches the level LC corresponding to the reference pressure command value P0.

-In the above embodiment, the respiratory state of the patient 63 is determined based on the measurement result of the flow rate sensor 32, but it may be determined by another method.
For example, the respiratory state may be determined based on the measurement result of the pressure sensor 31.

Further, the current flowing through the motor 23 shown in FIG. 3 may be measured by a current sensor and determined based on the measurement result. The respiratory state in patient 63 manifests itself as a change in load on the motor 23. For example, when the patient 63 is in the inspiratory state, the load on the motor 23 is small, and when the patient 63 is in the expiratory state, the load on the motor 23 is large. The amount of current in the motor 23 changes according to this load. In this way, the respiratory state is determined by the current flowing through the motor 23.

-In the above embodiment, the amplification factor β is set to "0" and the second pressure control unit 42 is invalidated, but it may be invalidated by another method. For example, the conversion result of the conversion unit 42b may be set to "0". Further, in the calculation unit 45, the second speed command B2 may be invalidated, that is, the second speed command B2 may not be added.

-In the above embodiment, the case of supplying a gas (for example, air) as a fluid has been described, but it may also be used in the case of supplying a gas-liquid mixture containing a mist-like liquid. Further, in the above embodiment, the fluid control device 10 is connected to the patient 63 via the tube 61 and the mask 62, but a cannula may be used instead of the mask 62.

10 ... Fluid control device, 11 ... Housing, 14 ... Inflow port, 15 ... Discharge port, 21 ... Fan case, 21a ... Suction port, 21b ... Discharge path, 22 ... Fan, 23 ... Motor (drive unit), 30 ... Control unit, 31 ... Pressure sensor (pressure measurement unit), 32 ... Flow sensor (detection unit), 33 ... Motor amplifier (current supply unit), 34 ... Hall sensor (speed measurement unit), 41 ... First pressure control unit , 41a, 42b ... Conversion unit, 41b, 42c ... Amplification unit, 42a ... Calculation unit, 42 ... Second pressure control unit, 44 ... Low pass filter, 45 ... Calculation unit (Drive command generation unit), 61 ... Tube (ream) Passage), 62 ... Mask, 63 ... Patient, B1 ... First speed command, B2 ... Second speed command, P0 ... Reference pressure command value, Pc ... Decompression amount, P1 ... Pressure command value, Pf ... Measured pressure value , S1, S2 ... speed command, Vm ... drive command, α, β ... amplification factor.

Claims (6)

A fluid control device used for positive airway pressure
With fans
A drive unit that rotationally drives the fan and
A housing having an inflow port for accommodating the fan and flowing a fluid by the rotational drive of the fan, and a discharge port for discharging the fluid by the rotational drive of the fan.
A communication passage that communicates the discharge port with the nasal cavity or oral cavity,
A detection unit that is arranged in the communication passage or the housing and can detect the flow velocity or flow rate of the fluid.
A pressure measuring unit that is arranged in the communication passage or the housing and outputs a measured pressure value that measures the pressure in the communication passage or the housing.
A first pressure control unit that generates a first speed command related to the rotation speed of the fan based on a predetermined pressure command value set in advance.
A second pressure control unit that generates a second speed command related to the rotation speed of the fan based on the deviation between the pressure command value and the measured pressure value.
A drive command generation unit that generates a drive command for the drive unit based on the first speed command and the second speed command.
A current supply unit that supplies a drive current to the drive unit based on the drive command,
A switching control unit that invalidates the second pressure control unit when the detection unit detects a flow rate or flow velocity of the fluid lower than a predetermined value.
Have a, a speed measuring unit that measures a rotation speed of the fan,
After the detection unit detects the flow rate or flow velocity of the fluid lower than the predetermined value, the switching control unit sets the pressure at the time of expiration when the rotation speed of the fan is equal to the rotation speed of the fan according to the drive command. A fluid control device, characterized in that it is determined that the pressure has been reached and the second pressure control unit is enabled . The fluid control according to claim 1, wherein the detection unit sets the pressure command value to a value lower than the reference pressure command value when detecting the flow rate or the flow velocity of the fluid lower than the predetermined value. apparatus. A fluid control device used for positive airway pressure
With fans
A drive unit that rotationally drives the fan and
A housing having an inflow port for accommodating the fan and flowing a fluid by the rotational drive of the fan, and a discharge port for discharging the fluid by the rotational drive of the fan.
A communication passage that communicates the discharge port with the nasal cavity or oral cavity,
A detection unit that is arranged in the communication passage or the housing and can detect whether the flow rate or the flow velocity of the fluid is higher or lower than a predetermined value.
A pressure measuring unit that is arranged in the communication passage or the housing and outputs a measured pressure value that measures the pressure of the fluid.
A first pressure control unit that generates a first speed command related to the rotation speed of the fan based on a predetermined pressure command value set in advance.
A second pressure control unit that generates a second speed command related to the rotation speed of the fan based on the deviation between the pressure command value and the measured pressure value.
A drive command generation unit that generates a drive command for the drive unit based on the first speed command and the second speed command.
A current supply unit that supplies a drive current to the drive unit based on the drive command,
A switching control unit that invalidates the second pressure control unit when the detection unit detects a flow rate or flow velocity of the fluid higher than the predetermined value.
Possess a speed measurement unit for measuring the rotational speed of the fan,
After the detection unit detects the flow rate or flow velocity of the fluid higher than the predetermined value, the switching control unit sets the pressure at the time of intake when the rotation speed of the fan is equal to the rotation speed of the fan according to the drive command. A fluid control device, characterized in that it is determined that the pressure has been reached and the second pressure control unit is enabled . The third aspect of claim 3 , wherein when the detection unit detects a flow rate or a flow velocity of the fluid higher than the predetermined value, the pressure command value is set as a reference pressure command value which is a pressure at the time of intake. Fluid control device. The fluid control device according to any one of claims 1 to 4 , wherein the detection unit detects a flow rate or a flow velocity of the fluid higher than the predetermined value to detect a switch from exhalation to inspiration. .. The first pressure control unit amplifies the first conversion unit that converts the pressure command value into a speed command and the speed command converted by the first conversion unit, and issues the first speed command. It has a first amplification unit that outputs
The second pressure control unit includes a calculation unit that calculates a deviation pressure value that is a deviation between the pressure command value and the measured pressure value, and a second conversion unit that converts the deviation pressure value into a speed command. It has a second amplification unit that amplifies the speed command converted by the second conversion unit and outputs the second speed command.
The switching control unit enables the second pressure control unit by setting the amplification factor β of the second amplification unit to “1”, and invalidates the second pressure control unit by setting the amplification factor β to “0”. When the second pressure control unit is disabled, the amplification factor α of the first amplification unit is set to 1, and when the second pressure control unit is enabled, the amplification factor of the first amplification unit is amplified. The fluid control device according to any one of claims 1 to 5, wherein the rate α is set to a value in the range of 1>α> 0.