Breathing machine air inlet pressure control method and system and computer program product

Abstract

The invention provides a breathing machine air inlet pressure control method and system and a computer program product. The method comprises the steps that a flow signal collected by an air path flow sensor is obtained, and a flow collection function is generated; according to the collection flow function, generating a reconstruction signal through time domain signal reconstruction; according to the reconstructed signal and a pressure signal collected by a pressure sensor, obtaining an estimated patient end pressure signal; and controlling the rotating speed of the fan by taking the estimated patient end pressure signal as a feedback signal of air inlet pressure closed-loop regulation. The method has the advantages that the collected flow signals are reconstructed through the time domain signals, the real-time flow reconstruction signals are obtained to achieve phase compensation of the collected signals, then pressure control with the good following effect is achieved, and the cost of development equipment is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of ventilators, and in particular relates to a ventilator intake pressure control method, system and computer program product. Background Art

[0002] The control target of the non-invasive ventilator involved in the prior art is the pressure on the patient side. The pressure on the patient side refers to the force applied by the ventilator when delivering airflow to the patient's lungs through the pipeline. This pressure is controlled by the electronic control system in the ventilator to ensure proper gas flow. However, due to the limitations of manufacturing process and production cost, it is impossible to directly collect pressure from the patient side. Generally, it is necessary to collect the pressure value collected by the pressure sensor inside the ventilator equipment and the flow value collected by the flow sensor, and estimate the pressure on the patient side based on the air resistance characteristics of the ventilator equipment system, and use this as the feedback value for the pressure closed-loop regulation. The pressure estimation formula on the patient side is P a =P S -f(Q s ), where: P a is the patient end pressure, P S Q is the pressure collected by the gas line pressure sensor at the equipment end. s is the flow rate collected by the gas flow sensor, and f(Q s ) is the air resistance characteristic of the equipment air path related to airflow.

[0003] It can be seen from the above formula that the estimation and control of patient pressure are restricted by the acquisition of flow sensors and pressure sensors. The acquisition response of pressure sensors is relatively fast, and the requirements for gas circuit design are relatively low, and only simple digital signal processing is required. For flow sensors, they are greatly affected by sensor prices and gas circuit structure design. If low-noise, low-latency signals are to be obtained, the requirements for sensor and gas circuit structure design are high, which means that it will bring greater product cost overhead. If only digital signal filtering is used to solve the acquisition noise, combined with the sensor acquisition delay and the delay of the pressure closed-loop control system, it will be very difficult to achieve pressure control. For this reason, it is often only possible to optimize the gas circuit design and improve the performance of the flow sensor, which greatly increases the product's bill of materials BOM (Bill of Material) and manufacturing cost. Summary of the invention

[0004] The purpose of the present invention is to overcome the technical defects of the existing flow acquisition signal in the intake pressure closed-loop control system due to the large noise and high delay of the air resistance characteristics of the ventilator equipment system and the delayed response of the hardware control.

[0005] In order to achieve the above object, the present application proposes a ventilator intake pressure control method, comprising:

[0006] Acquire the flow signal collected by the gas path flow sensor and generate a collection flow function;

[0007] Generate a reconstructed signal by reconstructing the time domain signal according to the collected flow function;

[0008] Obtaining an estimated patient-side pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor;

[0009] The estimated patient-end pressure signal is used as a feedback signal for closed-loop regulation of the intake pressure to control the fan speed.

[0010] Preferably, generating a reconstructed signal by signal reconstruction according to the acquisition amount function comprises the following steps:

[0011] Obtain the collected flow function and the real flow function of the system, and calculate the first phase delay;

[0012] Set the second phase delay;

[0013] A reconstructed signal is generated by signal reconstruction based on the accumulation of the first phase delay and the second phase delay.

[0014] Preferably, obtaining an estimated patient-side pressure signal according to the reconstructed signal and the pressure signal collected by the pressure sensor comprises the following steps:

[0015] Obtaining an estimated pressure signal according to the relationship between the reconstructed signal and the gas group characteristic function;

[0016] An estimated patient-end pressure signal is obtained based on the pressure signal collected by the pressure sensor and the difference between the estimated pressure signal.

[0017] Preferably, obtaining an estimated patient-side pressure signal according to the reconstructed signal and the pressure signal collected by the pressure sensor further includes the following steps:

[0018] It is determined whether the reconstruction signal is invalid.

[0019] Preferably, the determining whether the reconstruction signal is invalid comprises:

[0020] Calculating the absolute value of the difference between the reconstructed signal and the collected flow signal;

[0021] By setting the deviation threshold and comparing it with the absolute value, the corresponding estimated pressure signal is selected, and the piecewise function is as follows:

[0022]

[0023] when When the reconstructed signal is valid, the estimated pressure signal

[0024] when When the reconstructed signal fails, the estimated pressure signal

[0025] Among them, u is the transition factor, which is used to change Q when there is a sudden change in flow rate. k To set the deviation threshold, is the estimated pressure signal, is the absolute value of the difference between the reconstructed signal and the collected flow signal, is the reconstructed signal, Q s The collected signal

[0026] Preferably, the value of the transition factor u is as follows:

[0027]

[0028] The transition factor u depends on the previous moment and the current time t i of The ratio k of where i is greater than 1,

[0029]

[0030] Therefore, the beneficial effects brought about by the ventilator intake pressure control of the present application include:

[0031] 1. Make advance predictions based on the function reconstructed from the real-time sampled flow signal, and use phase compensation to offset the feedback delay caused by the actuator;

[0032] 2. The pressure control based on signal reconstruction takes into account the failure judgment of the reconstruction function, thereby ensuring that the pressure control can transition smoothly when a sudden flow rate change occurs.

[0033] 3. Signal filtering based on signal reconstruction can eliminate the influence of interference signals on pressure control performance, improve the control accuracy of the system, and maintain the system response speed.

[0034] 4. The prediction time selection method of the reconstructed signal realizes the response of pressure control. In practical applications, pressure control is mostly controlled by motor or valve. For such control, a certain amount of time is required to respond. The phase shift time is confirmed to meet the system requirements.

[0035] 5. The application of signal reconstruction observer in pressure control can achieve pressure control with better following effect, which reduces the cost of modifying ventilator equipment compared with modifying the structure.

[0036] The present application also discloses a system for controlling the intake pressure of a ventilator, comprising:

[0037] A flow collection module is used to obtain the flow signal collected by the gas path flow sensor and generate a collection flow function;

[0038] A signal reconstruction module is used to generate a reconstructed signal by reconstructing the time domain signal according to the collected flow function, wherein the collected flow function and the real flow function of the system are obtained, and a first phase delay is calculated; a second phase delay is set; and a reconstructed signal is generated by signal reconstruction according to the accumulation of the first phase delay and the second phase delay;

[0039] A patient-side pressure estimation module, used for obtaining an estimated patient-side pressure signal according to the reconstructed signal and the pressure signal collected by the pressure sensor;

[0040] The control module is used to control the fan speed according to the estimated patient-end pressure signal as a feedback signal for closed-loop regulation of the intake pressure.

[0041] Preferably, the reconstructed signal module also includes a logic judgment module for judging whether the reconstructed signal is invalid, calculating the absolute value of the difference between the reconstructed signal and the collected flow signal, and setting a deviation threshold.

[0042] The value is compared with the absolute value, and the corresponding estimated pressure signal is selected. The piecewise function is as follows:

[0043]

[0044] when When the reconstructed signal is valid, the estimated pressure signal

[0045] when When the reconstructed signal fails, the estimated pressure signal

[0046] Among them, u is the transition factor, which is used to change Q when there is a sudden change in flow rate. k To set the deviation threshold, is the estimated pressure signal, is the absolute value of the difference between the reconstructed signal and the collected flow signal, is the reconstructed signal, Q s is the collected quantity signal.

[0047] Preferably, the value of the transition factor u is as follows:

[0048]

[0049] The transition factor u depends on the previous moment and the current time t i of The ratio k of where i is greater than 1,

[0050]

[0051] The present application also discloses a computer program product, comprising a computer program / instruction, which implements the steps of the method when executed by a processor.

[0052] Compared with the prior art, the advantages of the device for controlling the air intake pressure of a ventilator of the present application are the same as its control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of the structure of the ventilator of the present application is shown;

[0054] Figure 2 The ventilator intake pressure control flow chart of the present application is shown;

[0055] Figure 3 A schematic diagram of phase deviation in the time domain of the flow function of the present application is shown;

[0056] Figure 4 A module diagram of the ventilator air intake pressure control device of the present application is shown. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0058] like Figure 1 As shown, in this application, for ease of understanding, the ventilator is roughly divided into three parts, the interior of the device 100, and the breathing circuit 200, wherein the flow sensor 101, the fan 103, and the pressure sensor 105 are arranged inside the device 100, and the required air reaches the patient end 300 through the breathing circuit 200. Specifically, when the air flows inside the ventilator device 100, the flow sensor 101 collects the flow signal in real time, and the pressure sensor 105 collects the pressure signal in real time. When the patient end exhales and inhales or there are sudden changes such as respiratory disorders, the pressure sensor 105 collects the signal and will be quickly fed back to the MCU, but the flow sensor 101 collects the signal and the response delay will be caused by the fan speeding up or slowing down. Usually, the pressure sensor and the MCU form a closed-loop feedback system, and the ventilator intake system (such as motor speed, valve opening, etc.) is adjusted according to the sensor signal to achieve synchronization with the patient's respiratory demand control. According to the embodiment, for the dependence of the current ventilator pressure control on the air path structure and the flow sensor 101, that is, the formula P a =P S -f(Q s ), where P a is the patient end pressure, P S is the pressure collected by the gas path pressure sensor 105 at the equipment end, Qs is the flow rate collected by the gas path flow sensor 101, and f(Q s ) is the air resistance characteristic of the equipment gas circuit related to the airflow. According to the target pressure value and the real-time calculated patient end pressure value P a Calculate the deviation between the two and perform closed-loop feedback control.

[0059] If you want to increase the patient pressure P a To control the real-time performance, the flow rate Q needs to be collected through the flow sensor. s The corresponding f(Q s ) for acquisition optimization. s ) is an inherent characteristic of the system gas path, which requires a low-noise, high-real-time flow acquisition. However, to provide low-noise, high-real-time flow acquisition, high requirements are required for sensors and system structure design, and the cost will increase relatively. The present invention, starting from flow signal analysis, reduces system structure design and sensor performance requirements, while achieving pressure control with better following effect, thereby reducing equipment costs.

[0060] The technical concept of this application is to analyze the gas flow and pressure characteristics in the actual application of the ventilator system, adopt the system identification method, and obtain the approximate periodic function of the relationship between the gas flow and time. And the running process updates this function in time to achieve data reconstruction of the system gas flow collection and obtain a real-time reconstruction function And through signal reconstruction observation technology, data noise control is realized to achieve filtering function.

[0061] like Figure 2 As shown, according to the embodiment, in S201, the flow signal collected by the airway flow sensor is obtained and a collection flow function is generated. Through signal reconstruction, the time domain signal of the collected airway flow is reconstructed. The collection flow function is an approximate periodic function, using a sinusoidal signal as an example of a mathematical formula, but not limited to this, other periodic functions such as trigonometric functions, periodic piecewise functions, and periodic functions that conform to the output waveform of the ventilator are all covered in this application,

[0062]

[0063] Where D is the amplitude at t=0, Initial phase, period A is the flow amplitude coefficient for ease of understanding.

[0064] In S203, a reconstruction function is generated by reconstructing the time domain signal according to the collected flow function, thereby obtaining a reconstructed signal and realizing phase compensation of the collected signal.

[0065] The reconstruction function is a periodic function of time t, expressed as:

[0066] For the period T, the collected flow function Q s (t) is determined. It can be understood that the two functions have the same period, amplitude, and frequency, but different initial phases, so Q s (t) and is an approximate value. Therefore, we can adjust the reconstruction function The phase corresponding to the phase shift time can predict the flow signal data, thereby achieving the corresponding pressure advance adjustment. Phase compensation can be achieved by adjusting the phase shift time, and the system real flow signal Q sr And the flow sensor collects the flow signal Q s The phase deviation in the time domain is Figure 3 As shown, according to the embodiment, generating a reconstructed signal and implementing phase compensation of the collected signal according to the collected flow function includes the following steps:

[0067] At S2031, the collected flow function Q is obtained s (t) and the system real flow function Q sr (t), calculate the first phase delay t1;

[0068] In S2032, a second phase delay t2 is set;

[0069] In S2033, according to the accumulated t of the first phase delay and the second phase delay s =t2+t1, generate the reconstruction function, and get the reconstructed traffic signal accordingly The phase compensation of the collected signal is realized. According to the embodiment, the method of reconstructing the function is not limited to Fourier reconstruction, wavelet reconstruction and other methods. It can be seen that due to the data processing of the flow sensor, the collected flow signal Q s Relative to the system real flow signal Q sr There will be a phase delay of t1, and for the reconstructed signal By adjusting the reconstruction function observation time t s Corresponding phase, phase compensation can be achieved.

[0070] According to an embodiment, pressure control is achieved based on flow reconstruction.

[0071] The traffic reconstruction signal is obtained according to the above embodiment Can achieve relative to the system real flow signal Q sr The flow observation of the leading time t2, while the relative sensor collects the flow signal Q s Can be ahead of t s =t2+t1 time flow observation and phase compensation, where Figure 3It is shown that it should be noted that the time axis at position 0 is the real flow signal Q of the system sr The corresponding time domain phase, t1 lags behind t2.

[0072] The selection of the prediction time of the reconstruction function affects the accuracy and efficiency of the reconstruction. The following are the principles for selecting the prediction time of this application: The selection of t2 and t1 needs to be adjusted according to the actual system performance. The selection of t1 time is to obtain the system real flow signal Q through phase compensation. sr The same phase signal, the selection of t2 is to achieve the response of pressure control. The two signals are not related, because in practical applications, pressure control is mostly controlled by motors or valves, and such controls require a certain amount of time to respond, and the selection of t2 is to meet system selection, which can be understood as an empirical value in this application.

[0073] In S205, the patient-side pressure signal is estimated by calculation based on the reconstructed signal and the pressure signal collected by the pressure sensor, that is, the reconstructed signal is obtained by selecting t1 and t2. Substitute into the system air resistance characteristic function Obtaining the estimated pressure signal and then obtaining the patient-side pressure signal by calculation includes the following steps:

[0074] S2051 obtains an estimated pressure function signal based on the relationship between the reconstructed signal and the gas group characteristic function:

[0075]

[0076] S2052 estimates the patient-side pressure signal based on the pressure signal collected by the gas path pressure sensor at the device end and the pressure signal corresponding to the estimated pressure function, that is, simultaneously obtains the estimated patient-side pressure signal.

[0077]

[0078] According to the embodiment, in S207, the fan speed is controlled based on the estimated patient-side pressure signal as a feedback signal for closed-loop regulation of the intake pressure. Specifically, the estimated patient-side pressure signal is compared with the target signal in real time, and this is used as the feedback pressure signal for closed-loop regulation of the system pressure. In a closed-loop control system, a specific control algorithm (such as a proportional-integral-differential algorithm, a fuzzy control algorithm, or an adaptive control algorithm, etc.) is used to process the feedback signal, and an error signal is output to the control unit to adjust the fan speed output of the ventilator.

[0079] According to the embodiment, the reconstruction function is obtained according to the reconstruction observer. In actual working conditions, the actual gas flow rate will not remain unchanged for a period of time, but may change suddenly. Figure 3 , by collecting the flow function Qs Shift the time state to the left by (t1+t2) to obtain the reconstructed flow function Its expression is:

[0080]

[0081] That is, to reconstruct the signal Collect flow signal Q with flow sensor s At the same phase, observe the difference between the two values To determine the reconstruction function Is it invalid? The calculation formula is:

[0082]

[0083] Calculate the absolute value of the flow difference between the reconstructed signal and the collected flow signal.

[0084] By setting the deviation threshold Q k , to decide to apply to pressure control, the implementation function is as follows:

[0085]

[0086] Where u is the transition factor, which is used when a sudden change in flow occurs. To estimate the pressure signal value, is the absolute value of the flow difference between the reconstructed signal and the collected flow signal, To reconstruct the signal value, Q s To collect flow signal values. It is used to ensure smooth transition of pressure control when sudden flow changes occur.

[0087] According to an embodiment, if the last moment t i-1 The second , the transition factor depends on the previous moment and the current time t i of The ratio k,

[0088]

[0089] The value selection rules are as follows:

[0090]

[0091] According to an embodiment, determining whether the reconstruction function is invalid further includes:

[0092] when When the reconstructed flow function is valid, the estimated pressure function when When the reconstructed flow function is invalid, the estimated pressure function

[0093] Therefore, the beneficial effects brought about by the ventilator intake pressure control of the present application include:

[0094] 1. Make advance predictions based on the function reconstructed from the real-time sampled flow signal, and use phase compensation to offset the feedback delay caused by the actuator;

[0095] 2. The pressure control based on signal reconstruction takes into account the failure judgment of the reconstruction function, thereby ensuring that the pressure control can transition smoothly when a sudden flow rate occurs.

[0096] 3. Signal filtering based on signal reconstruction can eliminate the influence of interference signals on pressure control performance, improve the control accuracy of the system, and maintain the system response speed.

[0097] 4. The prediction time selection method of the reconstructed signal realizes the response of pressure control. In practical applications, pressure control is mostly controlled by motor or valve. For such control, a certain amount of time is required to respond. The phase shift time is confirmed to meet the system requirements.

[0098] 5. The application of signal reconstruction observer in pressure control can achieve pressure control with better following effect, which reduces the cost of modifying ventilator equipment compared with modifying the structure.

[0099] According to an embodiment of the present application, a device 400 for controlling the intake pressure of a ventilator is also provided. The device 400 includes: a flow collection module 401, a signal reconstruction module 403, a patient-end pressure estimation module 405 and a control module 407.

[0100] See also Figure 4 The flow collection module 401 is used to obtain the flow signal collected by the gas path flow sensor and generate a collection flow function.

[0101] The reconstruction signal module 403 is used to generate a reconstructed signal through time domain signal reconstruction based on the collected flow function, wherein the collected flow function and the real flow function of the system are obtained, and the first phase delay is calculated; the second phase delay is set; and the reconstructed signal is generated through signal reconstruction based on the accumulation of the first phase delay and the second phase delay.

[0102] The patient-side pressure estimation module 405 is used to obtain an estimated patient-side pressure signal according to the reconstructed signal and the pressure signal collected by the pressure sensor.

[0103] The control module 407 is used to control the fan speed according to the estimated patient-end pressure signal as a feedback signal for closed-loop regulation of the intake pressure.

[0104] Preferably, the reconstruction signal module 403 also includes a logic judgment module 4031, which is used to judge whether the reconstruction signal is invalid, calculate the absolute value of the difference between the reconstruction signal and the collected flow signal, and

[0105] Value comparison, select the corresponding estimated pressure signal, the piecewise function is as follows:

[0106]

[0107] when When the reconstructed signal is valid, the estimated pressure signal

[0108] when When the reconstructed signal fails, the estimated pressure signal

[0109] Among them, u is the transition factor, which is used to change Q when a sudden flow occurs. k To set the deviation threshold, To estimate the pressure signal, is the absolute value of the difference between the reconstructed signal and the collected flow signal, To reconstruct the signal, Q s is the collected signal. The value of u is the same as that in the above method.

[0110] The embodiment of the present invention may also provide a computer program product, including a computer program / instruction. When the computer program / instruction is executed by a processor, each step in the above method embodiment can be implemented.

[0111] The processor may be a central processing unit (CPU). The processor may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or a combination of the above chips.

[0112] The memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer executable programs and modules, such as the program instructions / modules corresponding to the key shielding method of the vehicle-mounted display device in the embodiment of the present invention. The processor executes various functional applications and data processing of the processor by running the non-transitory software programs, instructions and modules stored in the memory.

[0113] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created by the processor, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0114] The one or more modules are stored in the memory, and when executed by the processor, the method described in this embodiment is performed.

[0115] The embodiment of the present invention also provides a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the aforementioned edge computing server deployment method are implemented. The computer-readable storage medium can be a tangible storage medium, such as a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable storage disk, a CD-ROM, or any other form of storage medium known in the technical field.

[0116] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0117] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0118] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0119] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A method for controlling the intake pressure of a ventilator, characterized in that: The method comprises the following steps: Acquire the flow signal collected by the gas path flow sensor and generate a collection flow function; Generate a reconstructed signal by reconstructing the time domain signal according to the collected flow function; Obtaining an estimated patient-side pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor; The estimated patient-end pressure signal is used as a feedback signal for closed-loop regulation of the intake pressure to control the fan speed.

2. The method according to claim 1, characterized in that The method of generating a reconstructed signal by signal reconstruction according to the acquisition amount function comprises the following steps: Obtain the collected flow function and the real flow function of the system, and calculate the first phase delay; Set the second phase delay; A reconstructed signal is generated by signal reconstruction based on the accumulation of the first phase delay and the second phase delay.

3. The method according to claim 1, characterized in that Obtaining an estimated patient-side pressure signal according to the reconstructed signal and the pressure signal collected by the pressure sensor comprises the following steps: Obtaining an estimated pressure signal according to the relationship between the reconstructed signal and the gas group characteristic function; An estimated patient-end pressure signal is obtained based on the pressure signal collected by the pressure sensor and the difference between the estimated pressure signal.

4. The method according to claim 1, characterized in that: According to the reconstructed signal and the pressure signal collected by the pressure sensor, an estimated patient-side pressure signal is obtained, which also includes the steps of: It is determined whether the reconstruction signal is invalid.

5. The method according to claim 3, characterized in that: The determining whether the reconstruction signal is invalid comprises: Calculating the absolute value of the difference between the reconstructed signal and the collected flow signal; By setting the deviation threshold and comparing it with the absolute value, the corresponding estimated pressure signal is selected, and the piecewise function is as follows: when When the reconstructed signal is valid, the estimated pressure signal when When the reconstructed signal fails, the estimated pressure signal Among them, u is the transition factor, which is used to change Q when there is a sudden change in flow rate. k To set the deviation threshold, is the estimated pressure signal, is the absolute value of the difference between the reconstructed signal and the collected flow signal, is the reconstructed signal, Q s is the collected quantity signal.

6. The method according to claim 5, characterized in that The value of the transition factor u is as follows: The transition factor u depends on the previous moment and the current time t i of The ratio k of where i is greater than 1, 7. A ventilator intake pressure control system, characterized in that: The control system comprises: A flow collection module is used to obtain the flow signal collected by the gas path flow sensor and generate a collection flow function; A signal reconstruction module is used to generate a reconstructed signal by reconstructing the time domain signal according to the collected flow function, wherein the collected flow function and the real flow function of the system are obtained, and a first phase delay is calculated; a second phase delay is set; and a reconstructed signal is generated by signal reconstruction according to the accumulation of the first phase delay and the second phase delay; A patient-side pressure estimation module, used for obtaining an estimated patient-side pressure signal according to the reconstructed signal and the pressure signal collected by the pressure sensor; The control module is used to control the fan speed according to the estimated patient-end pressure signal as a feedback signal for closed-loop regulation of the intake pressure.

8. The control system according to claim 7, characterized in that: The reconstructed signal module also includes a logic judgment module for judging whether the reconstructed signal is invalid, calculating the absolute value of the difference between the reconstructed signal and the collected flow signal, and selecting the corresponding estimated pressure signal by comparing the set deviation threshold with the absolute value. The piecewise function is as follows: when When the reconstructed signal is valid, the estimated pressure signal when When the reconstructed signal fails, the estimated pressure signal Among them, u is the transition factor, which is used to change Q when there is a sudden change in flow rate. k To set the deviation threshold, is the estimated pressure signal, is the absolute value of the difference between the reconstructed signal and the collected flow signal, is the reconstructed signal, Q s is the collected quantity signal.

9. The control system according to claim 8, characterized in that: The value of the transition factor u is as follows: The transition factor u depends on the previous moment and the current time t i of The ratio k of where i is greater than 1, 10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to claims 1-6 are implemented.

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