A breathing device air supply system and control method using a single sensor

Abstract

A single-sensor air supply system and control method for a respiratory device, the system includes an air supply pipeline, a turbofan, and a laminar flow structure; the air inlet end of the air supply pipeline is connected to an air source, and the air outlet end is connected to an air inlet of a humidification device; it also includes a differential pressure sensor and a three-way solenoid valve; the differential pressure sensor includes two pressure detection ports, which are respectively connected to the air inlet and air outlet of the laminar flow structure; the three-way solenoid valve includes three interfaces, the first interface is connected to the first detection port of the differential pressure sensor, the second interface is connected to the air inlet end of the laminar flow structure, and the third interface is connected to the external environment; when working, the first interface and the second interface are connected, or the first interface and the third interface are connected. The present invention uses only one differential pressure sensor, combined with a three-way solenoid valve to switch the pressure measuring port of the differential pressure sensor, respectively measure the flow parameters and pressure parameters of the ventilator, and can flexibly switch the measurement cycle of the parameters according to the treatment mode, simplifying the system structure, optimizing the control scheme, and reducing the system cost.

Description

Technical Field

[0001] The present invention relates to the field of medical equipment, and in particular to an air supply system and a control method for a respiratory device using a single sensor. Background Art

[0002] When using a ventilator, the pressure of the ventilator will fluctuate greatly when the user inhales and exhales. The pressure curve will have a large depression when the user inhales, and a large bulge when the user exhales. For ventilators that do not use valves, it is difficult to maintain a stable pressure output in the continuous positive airway pressure CPAP mode.

[0003] Chinese patent CN 107050600 B discloses a ventilator and a control method in a continuous positive airway pressure (CPAP) mode. The ventilator includes a flow sensor, a pressure sensor, a processor, a memory, and a control program stored in the memory and executable on the processor. When the control program is executed by the processor, the following steps are implemented: when the ventilator is in the CPAP mode, the flow curve and the pressure curve of the ventilator are obtained, the inhalation start time P is determined, and the output power of the fan of the ventilator is increased at the inhalation start time P; based on the flow curve and the pressure curve, the change rates of the flow and pressure are respectively obtained, and when the change rate of the flow is continuously greater than 0 and the change rate of the pressure is less than 0, the output power of the fan of the ventilator is intermittently increased; when the change rate of the pressure is greater than 0, the output power of the fan of the ventilator is intermittently reduced.

[0004] In summary, the ventilator of the prior art includes two sensors, namely, a flow sensor and a pressure sensor, which are used to obtain flow parameters and pressure parameters during the operation of the ventilator, respectively, and adjust the output power of the fan according to these two parameters to achieve pressure regulation. To a certain extent, the pressure can be quickly adjusted in the continuous positive airway pressure CPAP mode, so that the pressure output is stable and the user comfort is improved.

[0005] However, the above prior art has the following deficiencies:

[0006] First, using flow sensors and pressure sensors to obtain flow parameters and pressure parameters during the operation of the ventilator is relatively costly and increases the complexity of the system, which is not conducive to improving the reliability of the system to a certain extent;

[0007] 2. The measurement cycle of pressure and flow parameters cannot be adjusted dynamically and is not flexible enough.

[0008] Therefore, how to solve the above-mentioned deficiencies in the prior art has become a subject to be studied and solved by the present invention. Summary of the invention

[0009] The object of the present invention is to provide a breathing equipment air supply system and a control method using a single sensor.

[0010] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention at the system level is:

[0011] A single-sensor breathing apparatus air supply system comprises an air supply pipeline, and a turbo fan and a laminar flow structure sequentially connected to the air supply pipeline in series according to the air flow direction; wherein the air inlet end of the air supply pipeline is connected to an air source, and the air outlet end of the air supply pipeline is connected to the air inlet of a humidification device;

[0012] It also includes a differential pressure sensor and a three-way solenoid valve; wherein the differential pressure sensor includes two pressure detection ports, the first detection port is connected to the air inlet end of the laminar flow structure, and the second detection port is connected to the air outlet end of the laminar flow structure;

[0013] The three-way solenoid valve includes three interfaces, the first interface is connected to the first detection port of the differential pressure sensor, the second interface is connected to the air intake end of the laminar flow structure, and the third interface is connected to the external environment; the three-way solenoid valve has two working states after switching, in the first working state, the first interface and the second interface are connected; in the second working state, the first interface and the third interface are connected.

[0014] The relevant contents in the above technical solution are explained as follows:

[0015] 1. The above solution further comprises an air intake filter, which is connected in series to the rear side of the air intake end of the air supply pipeline and is located in front of the turbofan.

[0016] 2. The above solution further comprises an oxygen mixing chamber, which is connected in series to the front side or the rear side of the turbo fan on the air supply pipeline, and an oxygen input pipeline is connected to the oxygen mixing chamber.

[0017] 3. In the above scheme, the laminar flow structure is tubular, and a plurality of grid structures are arranged between the air inlet and the air outlet along the air flow direction, and each of the grid structures is arranged in parallel and spaced apart along the radial direction of the laminar flow structure, and a ventilation gap is formed between two adjacent grids.

[0018] In order to achieve the above object, the technical solution adopted by the present invention at the method level is:

[0019] A method for controlling air supply of a respiratory device using a single sensor, comprising:

[0020] S1, determine the trigger mode, if it is flow trigger, execute S21, if it is pressure trigger, execute S31;

[0021] S21, in the flow trigger mode, control the first interface and the second interface of the three-way solenoid valve to be connected, monitor the flow value fluctuation, and the duration is T1. At this time, if the flow fluctuation slope is less than a first trigger value, execute S22; if the flow fluctuation slope is greater than or equal to the first trigger value, execute S23;

[0022] S22, switch the first interface and the third interface of the three-way solenoid valve to conduct, monitor the pressure value fluctuation for a duration of T2, and then return to execute S21;

[0023] S23, the flow has been triggered, and the current flow fluctuation slope |K1| is recorded. If it is in the inhalation phase flow trigger mode, the turbo fan speed is increased; if it is in the exhalation phase flow trigger mode, the turbo fan speed is decreased, and the flow fluctuation slope |K2| is monitored at the same time; if |K2| is less than |K1|, return to execute S23; if |K2| is greater than or equal to |K1|, execute S24;

[0024] S24, the flow trigger response is completed, the first interface and the third interface of the three-way solenoid valve are switched to conduction, the pressure value fluctuation is monitored for a duration of T2, and then the process returns to S21;

[0025] S31, in the pressure trigger mode, control the first interface and the third interface of the three-way solenoid valve to be connected, monitor the pressure value fluctuation, and the duration is T4. At this time, if the pressure fluctuation slope is less than a second trigger value, execute S32; if the pressure fluctuation slope is greater than or equal to the second trigger value, execute S33;

[0026] S32, switching the first interface and the second interface of the three-way solenoid valve to conduct, monitoring the flow value fluctuation, the duration is T5, and then returning to execute S31;

[0027] S33, the pressure has been triggered, and the current pressure fluctuation slope |K3| is recorded. If it is in the inhalation phase pressure trigger mode, the turbo fan speed is increased; if it is in the exhalation phase pressure trigger mode, the turbo fan speed is decreased, and the pressure fluctuation slope |K4| is monitored at the same time; if |K4| is less than |K3|, return to execute S33; if |K4| is greater than or equal to |K3|, execute S34;

[0028] S34, the pressure trigger response is completed, the first interface and the second interface of the three-way solenoid valve are switched to conduction, the flow value fluctuation is monitored for a duration of T5, and then the process returns to execute S31.

[0029] The relevant contents in the above technical solution are explained as follows:

[0030] 1. In the above scheme, each time range of T1~T5 is shorter than the respiratory cycle.

[0031] 2. In the above solution, the first trigger value and the second trigger value are set by the user according to ventilation needs.

[0032] In order to achieve the above object, another technical solution adopted by the present invention at the method level is:

[0033] A method for controlling air supply of a respiratory device using a single sensor, comprising:

[0034] S1, start running;

[0035] S2, keep the first interface and the third interface of the three-way solenoid valve connected;

[0036] S3, monitoring the pressure fluctuation, if the pressure fluctuation slope is less than a first trigger value, returning to execute S3, if the pressure fluctuation slope is greater than or equal to the first trigger value, executing S4;

[0037] S4: The pressure has been triggered, the first interface and the second interface of the three-way solenoid valve are switched to conduction, and the speed of the turbo fan is increased;

[0038] S5, monitoring the flow value fluctuation, if the flow fluctuation slope is less than a second trigger value, returning to execute S5, if the flow fluctuation slope is greater than or equal to the second trigger value, executing S6;

[0039] S6, the flow has been triggered, the first interface and the third interface of the three-way solenoid valve are switched to conduction, and the speed of the turbo fan is reduced, and then the process returns to S3.

[0040] The relevant contents in the above technical solution are explained as follows:

[0041] 1. In the above solution, the first trigger value and the second trigger value are set by the user according to ventilation needs.

[0042] The working principle and advantages of the present invention are as follows:

[0043] The present invention discloses an air supply system for a respiratory device using a single sensor, comprising an air supply pipeline, a turbofan, and a laminar flow structure; the air inlet end of the air supply pipeline is connected to an air source, and the air outlet end is connected to an air inlet of a humidification device; the system also comprises a differential pressure sensor and a three-way solenoid valve; the differential pressure sensor comprises two pressure detection ports, which are respectively connected to an air inlet and an air outlet of the laminar flow structure; the three-way solenoid valve comprises three interfaces, the first interface is connected to a first detection port of the differential pressure sensor, the second interface is connected to an air inlet end of the laminar flow structure, and the third interface is connected to an external environment; when working, the first interface and the second interface are connected, or the first interface and the third interface are connected.

[0044] Compared with the prior art, the present invention uses only one differential pressure sensor and combines a three-way solenoid valve to switch the pressure measuring port of the differential pressure sensor to measure the flow parameters and pressure parameters of the ventilator respectively. The measurement cycle of the parameters can be flexibly switched according to the treatment mode, which has the following advantages:

[0045] 1. A single sensor can be used to measure pressure parameters and flow parameters, simplifying the system structure, optimizing the control scheme, and reducing system costs;

[0046] 2. The measurement cycle of pressure and flow parameters can be adjusted dynamically, making it more flexible to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Attached Figure 1 The structural principle framework of the gas supply system of the embodiment of the present invention is shown in FIG. Figure 1 ;

[0048] Attached Figure 2 The structural principle framework of the gas supply system of the embodiment of the present invention is shown in FIG. Figure 2 ;

[0049] Attached Figure 3 It is a cross-sectional schematic diagram of a laminar flow structure in an air supply system according to an embodiment of the present invention;

[0050] Attached Figure 4 A three-dimensional perspective view of a laminar flow structure in an air supply system according to an embodiment of the present invention;

[0051] Attached Figure 5 A flowchart of a control method according to an embodiment of the present invention;

[0052] Attached Figure 6 A flow fluctuation slope table according to an embodiment of the present invention;

[0053] Attached Figure 7 A pressure fluctuation slope table of an embodiment of the present invention;

[0054] Attached Figure 8 The figure is a flowchart of another control method according to an embodiment of the present invention.

[0055] In the above drawings: 1. air supply pipeline; 2. turbo fan; 3. laminar flow structure; 4. air inlet; 5. humidification device; 6. differential pressure sensor; 7. three-way solenoid valve; A. first detection port; B. second detection port; a. first interface; b. second interface; c. third interface; 8. air inlet filter; 9. oxygen mixing chamber; 10. oxygen input pipeline; 11. grid structure; 12. ventilation gap. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0057] Embodiment: The present invention will be clearly described below with diagrams and detailed descriptions. After understanding the embodiments of the present invention, any person skilled in the art can make changes and modifications based on the techniques taught by the present invention without departing from the spirit and scope of the present invention.

[0058] The terms used herein are only for describing specific embodiments and are not intended to be limiting of the present invention. Singular forms such as "a", "this", "here", "this" and "the" as used herein also include plural forms.

[0059] The terms “first”, “second”, etc. used in this document do not specifically refer to an order or sequence, nor are they used to limit the present case. They are only used to distinguish components or operations described with the same technical terms.

[0060] The terms “include,” “including,” “have,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0061] The terms used in this document generally have the ordinary meaning of each term used in this field, in the context of the case and in the specific context, unless otherwise noted. Certain terms used to describe the present invention will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the present invention.

[0062] See attached Figures 1 to 4 As shown, a respiratory equipment air supply system using a single sensor includes an air supply pipeline 1, and a turbo fan 2 and a laminar flow structure 3 connected in series to the air supply pipeline 1 in the direction of air flow; wherein the air inlet end 4 of the air supply pipeline 1 is connected to an air source, and the air outlet end of the air supply pipeline 1 is connected to the air inlet of a humidification device 5.

[0063] It also includes a differential pressure sensor 6 and a three-way solenoid valve 7; wherein the differential pressure sensor 6 includes two pressure detection ports, the first detection port A is connected to the air inlet end of the laminar flow structure 3, and the second detection port B is connected to the air outlet end of the laminar flow structure 3 (i.e., the air inlet of the humidification device 5).

[0064] The three-way solenoid valve 7 includes three interfaces, the first interface a is connected to the first detection port A of the differential pressure sensor 6, the second interface b is connected to the air inlet end of the laminar flow structure 3, and the third interface c is connected to the external environment; the three-way solenoid valve 7 has two working states after switching. In the first working state, the first interface a and the second interface b are connected. At this time, the differential pressure sensor 6 is used to detect the pressure difference between the air inlet end and the air outlet end of the laminar flow structure 3, and the output signal value of the differential pressure sensor 6 can be converted into a gas flow value flowing through the laminar flow structure 3; in the second working state, the first interface a and the third interface c are connected. At this time, the differential pressure sensor 6 is used as a pressure sensor to detect the pressure value at the air outlet end of the laminar flow structure 3 (that is, the pressure value at the air inlet of the humidification device 5), and the pressure value is positively correlated with the pressure value at the patient end.

[0065] Preferably, an air intake filter 8 is further included, which is serially connected to the rear side of the air intake end of the air supply pipeline 1 and is located in front of the turbofan 2. The air intake filter 8 can filter out particulate matter, impurities, etc. in the inhaled air.

[0066] The turbofan 2 can perform work on the gas through the rotation of the impeller, convert kinetic energy into pressure energy, and output gas with a certain pressure and flow rate.

[0067] The laminar flow structure 3 can provide a certain air path impedance and play a role in stabilizing the flow.

[0068] After being filtered, the air enters the air inlet of the turbofan 2. The air outlet of the turbofan 2 is connected to the laminar flow structure 3. After the gas passes through the laminar flow structure 3 for steady flow, it enters the humidification device 5 to heat and humidify the gas, and finally reaches the patient end.

[0069] like Figure 2 As shown, it may also include an oxygen mixing chamber 9, which is serially connected to the front side or the rear side of the turbo fan 2 on the air supply pipeline 1, and an oxygen input pipeline 10 is connected to the oxygen mixing chamber 9.

[0070] like Figure 3 , 4 As shown, the laminar flow structure 3 is tubular, and a plurality of grid structures 11 are arranged between the air inlet and the air outlet along the air flow direction. The grid structures 11 are arranged in parallel and spaced apart along the radial direction of the laminar flow structure 3 , and a ventilation gap 12 is formed between two adjacent grid structures 11 .

[0071] like Figures 5 to 7 As shown, a gas supply control method of the present invention is now described as follows: the method is implemented by the gas supply system, including:

[0072] S1. Determine the trigger mode. If it is flow trigger, execute S21; if it is pressure trigger, execute S31. The selection of the specific trigger mode depends on the user's use requirements or the manufacturer's control logic requirements.

[0073] S21, in the flow trigger mode, control the first interface a and the second interface b of the three-way solenoid valve 7 to be turned on, monitor the flow value fluctuation, and keep it for a duration of T1. At this time, if the flow fluctuation slope is less than a first trigger value, execute S22; if the flow fluctuation slope is greater than or equal to the first trigger value, execute S23;

[0074] S22, switch the first interface a and the third interface c of the three-way solenoid valve 7 to conduct, monitor the pressure value fluctuation for a duration of T2, and then return to execute S21;

[0075] S23, the flow has been triggered, and the current flow fluctuation slope |K1| is recorded. If it is in the inhalation phase flow trigger mode, the speed of turbo fan 2 is increased. If it is in the exhalation phase flow trigger mode, the speed of turbo fan 2 is reduced, and the flow fluctuation slope |K2| is monitored at the same time; if |K2| is less than |K1|, return to execute S23, if |K2| is greater than or equal to |K1|, execute S24;

[0076] S24, the flow trigger response is completed, the first interface a and the third interface c of the three-way solenoid valve 7 are switched to conduction, the pressure value fluctuation is monitored for a duration of T2, and then the process returns to S21;

[0077] S31, in the pressure trigger mode, control the first interface a and the third interface c of the three-way solenoid valve 7 to be connected, monitor the pressure value fluctuation, and keep it for a duration of T4. At this time, if the pressure fluctuation slope is less than a second trigger value, execute S32; if the pressure fluctuation slope is greater than or equal to the second trigger value, execute S33;

[0078] S32, switching the first interface a and the second interface b of the three-way solenoid valve 7 to conduct, monitoring the flow value fluctuation, the duration is T5, and then returning to execute S31;

[0079] S33, the pressure has been triggered, and the current pressure fluctuation slope |K3| is recorded. If it is in the inhalation phase pressure trigger mode, the speed of turbo fan 2 is increased. If it is in the exhalation phase pressure trigger mode, the speed of turbo fan 2 is reduced, and the pressure fluctuation slope |K4| is monitored at the same time; if |K4| is less than |K3|, return to execute S33, if |K4| is greater than or equal to |K3|, execute S34;

[0080] S34, the pressure trigger response is completed, the first interface a and the second interface b of the three-way solenoid valve 7 are switched to conduction, the flow value fluctuation is monitored for a duration of T5, and then the process returns to execute S31.

[0081] in, Figure 6 The switching cycle of the three-way solenoid valve 7 in the inspiratory phase flow trigger mode is given, wherein the preferred T1>T2 can improve the trigger response time. Before triggering, T1 is long and T2 is short, which can capture flow fluctuations more quickly, that is, reduce the situation where flow fluctuations occur during T2 and flow signals are not monitored in time; further, what is monitored during T2 can be a pressure signal, and the pressure fluctuation value is related to respiratory events. After a respiratory event occurs during T2, it is immediately switched to T1 flow monitoring. At this time, T2 is a dynamic change, that is, non-fixed.

[0082] T3 is the flow trigger period, which is the duration of the three-way solenoid valve 7 to maintain flow value monitoring. After the trigger is completed, it switches to pressure value monitoring. The same applies to exhalation, which will not be repeated. T3 is intended to illustrate the period for judging whether the flow trigger is completed. The duration of T3 may be longer than T1, that is, the flow monitoring stage is always in progress during the incomplete trigger period.

[0083] Figure 7 The switching cycle of the three-way solenoid valve 7 in the pressure trigger mode of the inhalation phase is given, wherein the preferred T4>T5 can improve the trigger response time, and T6 is the duration of the three-way solenoid valve 7 maintaining pressure value monitoring during the pressure trigger period. After the trigger is completed, it switches to flow value monitoring. The same is true for exhalation, which will not be repeated. T6 is intended to illustrate the period of judging whether the pressure trigger is completed. The duration of T6 may be longer than T4, that is, the pressure monitoring stage is always in progress during the incomplete trigger period.

[0084] Each time range of T1~T5 is less than the respiratory cycle. The respiratory cycle is the inverse of the current patient's respiratory frequency. The values ​​of T1~T5 are percentages of the respiratory cycle, which can be equal or unequal. The lower the percentage, the higher the frequency of valve switching, and the more uniform the sampling of the two parameter values ​​of pressure and flow relative to time distribution. This can be flexibly selected according to needs.

[0085] In this embodiment, the monitoring period of pressure and flow in the non-trigger stage is fixed. Except for T3, the intervals of the vertical lines in the figure are T1, T2, T1, T2... in sequence. In practice, it is not limited to fixed cycle switching, and can be combined with dynamic adjustments such as multiple breathing cycles and treatment modes to change the sampling rate of pressure and flow parameters.

[0086] like Figures 6-8 As shown, another gas supply control method of the present invention is described as follows: the method is implemented by the gas supply system, comprising:

[0087] S1, start running;

[0088] S2, keep the first interface a and the third interface c of the three-way solenoid valve 7 connected;

[0089] S3, monitoring the pressure fluctuation, if the pressure fluctuation slope is less than a first trigger value, returning to execute S3, if the pressure fluctuation slope is greater than or equal to the first trigger value, executing S4;

[0090] S4, the pressure has been triggered, the first interface a and the second interface b of the three-way solenoid valve 7 are switched to conduction, and the speed of the turbo fan 2 is increased;

[0091] S5, monitoring the flow value fluctuation, if the flow fluctuation slope is less than a second trigger value, returning to execute S5, if the flow fluctuation slope is greater than or equal to the second trigger value, executing S6;

[0092] S6, the flow has been triggered, the first interface a and the third interface c of the three-way solenoid valve 7 are switched to be connected, and the speed of the turbo fan 2 is reduced, and then the process returns to execute S3.

[0093] In this method, the speed of the turbo fan 2 needs to be increased because the pressure is used as a trigger during inhalation, and the speed of the turbo fan 2 needs to be decreased because the flow rate is used as a trigger during exhalation.

[0094] The first trigger value and the second trigger value are set by the user according to ventilation needs. The trigger value corresponds to the sensitivity of the respiratory device to inhalation or exhalation. Usually, the user can set the gear according to ventilation needs, and different gears correspond to different trigger value sizes.

[0095] This method combines the inhalation phase pressure triggering and the expiratory phase flow triggering, and does not require frequent switching of the three-way solenoid valve 7. It only needs to be switched twice in one breathing cycle. After the pressure is triggered, the pressure value can be calculated based on the pressure calibration value and the real-time flow compensation relationship during the process of the differential pressure sensor 6 monitoring the flow value. The monitoring of both pressure and flow parameters is taken into account, and the use of flow triggering in the expiratory phase can effectively avoid the situation of insufficient secondary inspiration.

[0096] Compared with the prior art, the present invention uses only one differential pressure sensor, combined with a three-way solenoid valve to switch the pressure measuring port of the differential pressure sensor, to measure the flow parameters and pressure parameters of the ventilator respectively, and can flexibly switch the parameter measurement cycle according to the treatment mode, with the following advantages: a single sensor can be used to measure the pressure parameters and flow parameters, which simplifies the system structure, optimizes the control scheme, and reduces the system cost; the measurement cycle of the pressure and flow parameters can be dynamically adjusted, and the application is more flexible.

[0097] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A breathing apparatus air supply system using a single sensor, characterized in that: It comprises an air supply pipeline, and a turbo fan and a laminar flow structure which are sequentially connected to the air supply pipeline in series according to the air flow direction; wherein the air inlet end of the air supply pipeline is connected to an air source, and the air outlet end of the air supply pipeline is connected to the air inlet of a humidification device; It also includes a differential pressure sensor and a three-way solenoid valve; wherein the differential pressure sensor includes two pressure detection ports, and the second detection port is connected to the air outlet end of the laminar flow structure; The three-way solenoid valve includes three interfaces, the first interface is connected to the first detection port of the differential pressure sensor, the second interface is connected to the air intake end of the laminar flow structure, and the third interface is connected to the external environment; the three-way solenoid valve has a first working state and a second working state after switching; in the first working state, the first interface and the second interface are connected; in the second working state, the first interface and the third interface are connected.

2. The breathing apparatus air supply system using a single sensor according to claim 1, characterized in that: It also includes an air intake filter, which is serially connected to the rear side of the air intake end of the air supply pipeline and is located at the front side of the turbofan.

3. The breathing apparatus air supply system using a single sensor according to claim 1, characterized in that: It also includes an oxygen mixing chamber, which is serially connected to the front side or the rear side of the turbo fan on the air supply pipeline, and an oxygen input pipeline is connected to the oxygen mixing chamber.

4. The breathing apparatus air supply system using a single sensor according to claim 1, characterized in that: The laminar flow structure is tubular, and a plurality of grid structures are arranged between the air inlet and the air outlet along the air flow direction. The grid structures are arranged in parallel and spaced apart along the radial direction of the laminar flow structure, and a ventilation gap is formed between two adjacent grids.

5. A method for controlling air supply of a respiratory device using a single sensor, characterized in that: The method is implemented by the gas supply system according to claim 1, and the method comprises: S1, determine the trigger mode, if it is flow trigger, execute S21, if it is pressure trigger, execute S31; S21, in the flow trigger mode, control the first interface and the second interface of the three-way solenoid valve to be connected, monitor the flow value fluctuation, and the duration is T1. At this time, if the flow fluctuation slope is less than a first trigger value, execute S22; if the flow fluctuation slope is greater than or equal to the first trigger value, execute S23; S22, switch the first interface and the third interface of the three-way solenoid valve to conduct, monitor the pressure value fluctuation for a duration of T2, and then return to execute S21; S23, the flow has been triggered, and the current flow fluctuation slope |K1| is recorded. If it is in the inhalation phase flow trigger mode, the turbo fan speed is increased; if it is in the exhalation phase flow trigger mode, the turbo fan speed is decreased, and the flow fluctuation slope |K2| is monitored at the same time; if |K2| is less than |K1|, return to execute S23; if |K2| is greater than or equal to |K1|, execute S24; S24, the flow trigger response is completed, the first interface and the third interface of the three-way solenoid valve are switched to conduction, the pressure value fluctuation is monitored for a duration of T2, and then the process returns to S21; S31, in the pressure trigger mode, control the first interface and the third interface of the three-way solenoid valve to be connected, monitor the pressure value fluctuation, and the duration is T4. At this time, if the pressure fluctuation slope is less than a second trigger value, execute S32; if the pressure fluctuation slope is greater than or equal to the second trigger value, execute S33; S32, switching the first interface and the second interface of the three-way solenoid valve to conduct, monitoring the flow value fluctuation, the duration is T5, and then returning to execute S31; S33, the pressure has been triggered, and the current pressure fluctuation slope |K3| is recorded. If it is in the inhalation phase pressure trigger mode, the turbo fan speed is increased; if it is in the exhalation phase pressure trigger mode, the turbo fan speed is decreased, and the pressure fluctuation slope |K4| is monitored at the same time; if |K4| is less than |K3|, return to execute S33; if |K4| is greater than or equal to |K3|, execute S34; S34, the pressure trigger response is completed, the first interface and the second interface of the three-way solenoid valve are switched to conduction, the flow value fluctuation is monitored for a duration of T5, and then the process returns to execute S31.

6. The method for controlling the air supply of a respiratory device using a single sensor according to claim 5, characterized in that: The time ranges of T1, T2, T4, and T5 are all shorter than the respiratory cycle.

7. The method for controlling the air supply of a respiratory device using a single sensor according to claim 5, characterized in that: The first trigger value and the second trigger value are set by the user according to ventilation needs.

8. A method for controlling air supply of a respiratory device using a single sensor, characterized in that: The method is implemented by the gas supply system according to claim 1, and the method comprises: S1, start running; S2, keep the first interface and the third interface of the three-way solenoid valve connected; S3, monitoring the pressure fluctuation, if the pressure fluctuation slope is less than a first trigger value, returning to execute S3, if the pressure fluctuation slope is greater than or equal to the first trigger value, executing S4; S4: The pressure has been triggered, the first interface and the second interface of the three-way solenoid valve are switched to conduction, and the speed of the turbo fan is increased; S5, monitoring the flow value fluctuation, if the flow fluctuation slope is less than a second trigger value, returning to execute S5, if the flow fluctuation slope is greater than or equal to the second trigger value, executing S6; S6, the flow has been triggered, the first interface and the third interface of the three-way solenoid valve are switched to conduction, and the speed of the turbo fan is reduced, and then the process returns to S3.

9. The method for controlling the air supply of a respiratory device using a single sensor according to claim 8, characterized in that: The first trigger value and the second trigger value are set by the user according to ventilation needs.

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