Method and system for controlling intake gas pressure of ventilator, and computer program product

Abstract

A method and system for controlling the intake gas pressure of a ventilator, and a computer program product. The method comprises: acquiring a flow signal collected by a gas path flow sensor (101) and generating a collected flow function (S201); on the basis of the collected flow function, performing time domain signal reconstruction to generate a reconstructed signal (S203); on the basis of the reconstructed signal and a pressure signal collected by a pressure sensor (105), obtaining an estimated patient end pressure signal (S205); and on the basis of the estimated patient end pressure signal serving as a feedback signal for intake gas pressure closed-loop regulation, controlling the rotation speed of a fan (103) (S207). The collected flow signal undergoes time domain signal reconstruction to obtain the real-time flow reconstructed signal, so as to implement phase compensation of the collected signal, thereby implementing pressure control having a good tracking effect, and reducing device development costs.

Description

A method, system, and computer program product for controlling the inlet pressure of a ventilator.

[0001] Related applications

[0002] This application claims priority to Chinese Patent Application No. 2024117314283, filed on November 28, 2024, entitled “A method, system and computer program product for controlling the intake pressure of a ventilator”, which is incorporated herein by reference. Technical Field

[0003] This invention belongs to the field of ventilator technology, and particularly relates to ventilator inlet pressure control methods, systems and computer programs. Background Technology

[0004] Existing non-invasive ventilators all target patient-side pressure, which refers to the force exerted by the ventilator when delivering airflow to the patient's lungs through the tubing. This pressure is controlled by the electronic control system within the ventilator to ensure proper gas flow. However, due to limitations in manufacturing processes and production costs, pressure cannot be directly measured from the patient's end. Generally, pressure values ​​are collected from pressure sensors and flow values ​​from flow sensors within the ventilator. Based on the air resistance characteristics of the ventilator system, the patient-side pressure is estimated and used as feedback for closed-loop pressure regulation. The formula for estimating patient-side pressure is P. a =P S -f(Q s ), where: P a For patient-side pressure, P S The pressure Q is collected by the air pressure sensor at the device end. s The flow rate collected by the gas flow sensor, and f(Q) s () refers to the air resistance characteristics of the air passage of equipment related to airflow.

[0005] As can be seen from the above formulas, the estimation and control of patient pressure are constrained by the data acquired by flow and pressure sensors. Pressure sensors have a faster response time and relatively lower requirements for gas path design, requiring only simple digital signal processing. However, flow sensors are significantly affected by sensor price and gas path design. Obtaining low-noise, low-delay signals requires more sophisticated sensor and gas path design, leading to higher product costs. If only digital signal filtering is used to address acquisition noise, combined with sensor acquisition delay and the delay of the pressure closed-loop control system, achieving accurate pressure control becomes very difficult. Therefore, the only solution is often to optimize the gas path design and improve flow sensor performance, significantly increasing the product's Bill of Materials (BOM) and manufacturing costs. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical defects of existing flow acquisition signals, such as high noise and high delay due to the air resistance characteristics of ventilator equipment systems, and delay in hardware control response, which lead to delays in the intake pressure closed-loop control system.

[0007] To achieve the above objectives, this application proposes a method for controlling the inlet pressure of a ventilator, comprising:

[0008] Acquire the flow signal collected by the gas flow sensor and generate the acquisition flow function;

[0009] Based on the aforementioned acquisition flow function, a reconstructed signal is generated through time-domain signal reconstruction;

[0010] Based on the reconstructed signal and the pressure signal collected by the pressure sensor, the estimated pressure signal at the patient end is obtained;

[0011] The estimated patient-side pressure signal is used as a feedback signal for closed-loop regulation of the intake pressure to control the fan speed.

[0012] Preferably, the step of generating a reconstructed signal by reconstructing the signal based on the acquired quantity function includes the following steps:

[0013] Obtain the collected flow function and the actual system flow function, and calculate the first phase delay;

[0014] Set a second phase delay;

[0015] Based on the sum of the first phase delay and the second phase delay, a reconstructed signal is generated through signal reconstruction.

[0016] Preferably, obtaining the estimated patient-end pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor includes the following steps:

[0017] Based on the relationship between the reconstructed signal and the gas group characteristic function, the estimated pressure signal is obtained;

[0018] The estimated patient-side pressure signal is obtained based on the difference between the pressure signal collected by the pressure sensor and the estimated pressure signal.

[0019] Preferably, the process of obtaining an estimated patient-end pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor further includes the following steps:

[0020] Determine whether the reconstructed signal is invalid.

[0021] Preferably, determining whether the reconstructed signal has failed includes:

[0022] Calculate the absolute value of the difference between the reconstructed signal and the acquired flow signal;

[0023] By comparing the set deviation threshold with the absolute value, the corresponding estimated pressure signal is selected, and the piecewise function is as follows:

[0024] when When the reconstructed signal is valid, the estimated pressure signal...

[0025] when When the reconstructed signal fails, the estimated pressure signal...

[0026] Where u is a transition factor, used to adjust Q in the event of a sudden change in flow rate. k To set a deviation threshold, The estimated pressure signal, The absolute value of the difference between the reconstructed signal and the acquired flow signal. For the reconstructed signal, Q s The acquired signal

[0027] Preferably, the transition factor u is determined according to the following rules:

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

[0029] Therefore, the beneficial effects of the ventilator inlet pressure control in this application include:

[0030] 1. A function reconstructed from real-time sampled flow signals is used for advance prediction, and phase compensation is used to offset the feedback delay caused by the actuator;

[0031] 2. Pressure control based on signal reconstruction takes into account the failure judgment of the reconstruction function, so as to ensure that the pressure control can smoothly transition in the event of sudden changes in flow.

[0032] 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.

[0033] 4. A method for selecting the prediction time of the reconstructed signal to achieve the response of pressure control. In practical applications, pressure control is mostly achieved using motors or valves. Such control requires a certain response time, which is confirmed by confirming that the phase shift time meets the system requirements.

[0034] 5. The application of signal reconstruction observers in pressure control enables pressure control with better tracking effect, and reduces the cost of modifying ventilator equipment compared to structural modification.

[0035] This application also discloses a system for controlling the inlet pressure of a ventilator, comprising:

[0036] The flow acquisition module is used to acquire the flow signal collected by the gas flow sensor and generate the acquisition flow function;

[0037] The reconstructed signal module is used to generate a reconstructed signal by reconstructing the time-domain signal according to the acquired flow function, wherein the acquired flow function and the actual system flow function are obtained, a first phase delay is calculated, a second phase delay is set, and a reconstructed signal is generated by reconstructing the signal according to the sum of the first phase delay and the second phase delay.

[0038] The patient-end pressure estimation module is used to obtain an estimated patient-end pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor.

[0039] The control module is used to control the fan speed based on the estimated patient end pressure signal as a feedback signal for closed-loop regulation of the intake pressure.

[0040] Preferably, the reconstructed signal module further includes a logic judgment module, used to determine whether the reconstructed signal is invalid, calculate the absolute value of the difference between the reconstructed signal and the acquired flow signal, and select the corresponding estimated pressure signal by comparing the absolute value with a set deviation threshold. The piecewise function is as follows:

[0041] when When the reconstructed signal is valid, the estimated pressure signal...

[0042] when When the reconstructed signal fails, the estimated pressure signal...

[0043] Where u is a transition factor, used to adjust Q in the event of a sudden change in flow rate. k To set a deviation threshold, The estimated pressure signal, The absolute value of the difference between the reconstructed signal and the acquired flow signal. For the reconstructed signal, Q s The acquired signal is referred to as "the acquired signal".

[0044] Preferably, the transition factor u is determined according to the following rules:

[0045] The transition factor u depends on the previous time step. and this moment t i of The ratio k, where i is greater than 1,

[0046] This application also discloses a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the method.

[0047] Compared with the prior art, the device for controlling the intake pressure of a ventilator in this application has the same advantages as its control method. Attached Figure Description

[0048] Figure 1 shows a schematic diagram of the ventilator structure of this application;

[0049] Figure 2 shows the ventilator inlet pressure control flowchart of this application;

[0050] Figure 3 shows a schematic diagram of the phase deviation in the time domain of the flow function of this application;

[0051] Figure 4 shows a block diagram of the ventilator inlet pressure control device of this application. Detailed Implementation

[0052] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0053] As shown in Figure 1, for ease of understanding, the ventilator in this application is roughly divided into three parts: the internal device 100, the breathing tubing 200, and the flow sensor 101, fan 103, and pressure sensor 105, which are located inside the device 100. The required air reaches the patient through the breathing tubing 200. Specifically, when 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 exhales or inhales, or when a sudden change occurs such as respiratory distress, the signal collected by the pressure sensor 105 is quickly fed back to the MCU, but the signal collected by the flow sensor 101 will have a response delay due to the fan's speed increase or decrease. Typically, the pressure sensor and the MCU form a closed-loop feedback system, adjusting the ventilator's air intake system (such as motor speed, valve opening, etc.) according to the sensor signals to achieve synchronization with the patient's breathing needs.

[0054] According to the embodiment, regarding the dependence of current ventilator pressure control on the airway structure and flow sensor 101, i.e., formula P a =P S -f(Q s ), where P a For patient-side pressure, P SThe pressure Q collected by the air pressure sensor 105 at the device end. s The flow rate collected by the gas flow sensor 101, and f(Q) s This refers to the air resistance characteristics of the equipment's airflow path. It is based on the target pressure value and the real-time calculated patient-end pressure value P. a Calculate the deviation between the two values ​​and implement closed-loop feedback control.

[0055] If we want to increase patient stress P a To control real-time performance, flow rate Q needs to be collected via a flow sensor. s The corresponding f(Q) s ) to optimize data collection. For f(Q) s Due to the inherent characteristics of the system's gas path, a low-noise, high-real-time flow acquisition is required. However, providing such low-noise, high-real-time flow acquisition demands high standards for sensor and system architecture design, which increases costs. This invention addresses this by focusing on flow signal analysis, reducing the requirements for system architecture design and sensor performance while achieving pressure control with good tracking performance, thereby reducing equipment costs.

[0056] The technical concept of this application is as follows: By analyzing the gas flow and pressure characteristics in the actual application of ventilator systems, and using a system identification method, an approximate periodic function relating gas flow to time is obtained. This function is updated in real time during the operation to reconstruct the system's gas flow data and obtain a real-time reconstruction function. Furthermore, data noise control is achieved through signal reconstruction observation technology, thus realizing the filtering function.

[0057] As shown in Figure 2, according to the embodiment, in step S201, the flow signal collected by the airway flow sensor is acquired and a collected flow function is generated. The time-domain signal of the collected airway flow is reconstructed through signal reconstruction. The collected flow function is an approximate periodic function, using a sine signal as an example of a mathematical formula, but it is not limited to this. Other periodic functions, such as trigonometric functions, periodic piecewise functions, and periodic functions conforming to the ventilator output waveform, are all covered in this application.

[0058] Where D is the amplitude at t=0, Initial phase, period A is the flow amplitude coefficient, which is easy to understand.

[0059] In S203, a reconstruction function is generated based on the acquired flow function, thereby obtaining the reconstructed signal and realizing phase compensation of the acquired signal.

[0060] The reconstruction function is a periodic function with respect to time t, expressed as:

[0061] The period T is determined by the collected flow function Q. s (t) is determined. This can be understood as the two functions having the same period, amplitude, and frequency, but different initial phases. Therefore, Q can be understood as... s (t) and This is an approximation. Therefore, the reconstruction function can be adjusted. The phase corresponding to the phase shift time can be used to predict the flow signal data, thereby achieving proactive pressure regulation. Phase compensation can be achieved by adjusting the phase shift time, thus revealing the true flow signal Q of the system. sr and flow sensor to collect flow signal Q s The phase deviation in the time domain is shown in Figure 3. According to the embodiment, based on the acquisition flow function, a reconstructed signal is generated and phase compensation of the acquisition signal is achieved, including the following steps:

[0062] The flow rate function Q is obtained in S2031. s (t) and the system's true flow function Q sr (t), the first phase delay t1 is calculated;

[0063] Set a second phase delay t2 in S2032;

[0064] In S2033, based on the accumulation t of the first phase delay and the second phase delay... s =t2+t1, generating the reconstruction function, and thus obtaining the reconstructed flow signal. Phase compensation of the acquired signal is achieved. According to the embodiment, the reconstruction function method is not limited to Fourier reconstruction, wavelet reconstruction, etc. It can be seen that due to the data processing of the flow sensor, the acquired flow signal Q... s Relative to the system's actual flow signal Q sr There will be a phase delay of t1, and for the reconstructed signal By adjusting the observation time t of the reconstruction function s The corresponding phase can achieve phase compensation.

[0065] According to the embodiment, pressure control is achieved based on flow reconstruction.

[0066] The flow reconstruction signal is obtained according to the above embodiments. It can realize the actual flow signal Q of the system. sr The flow rate observation is ahead of time t2, while the flow rate signal Q is acquired by the sensor. s Can be ahead of time s =Flow rate observation and phase compensation at time t2+t1, as shown in Figure 3. It should be noted that the time axis at position 0 represents the actual system flow rate signal Q. sr The corresponding time-domain phase, t1 lags behind t2.

[0067] The choice of prediction time for the reconstruction function affects the accuracy and efficiency of the reconstruction. The following are the principles for selecting the prediction time in this application: the selection of t2 and t1 needs to be adjusted based on the actual system performance. The selection of t1 is to obtain a signal consistent with the actual system flow signal Q through phase compensation. sr The same phase signal is used, but the choice of t2 is to achieve the response of pressure control. The two signals are not related because in practical applications, pressure control is mostly carried out by motor or valve control, which requires a certain amount of time to respond. The choice of t2 is to meet the system selection, and it can be understood as an empirical value in this application.

[0068] In S205, based on the reconstructed signal and the pressure signal collected by the pressure sensor, the estimated pressure signal at the patient end is calculated, 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 calculating the patient-side pressure signal involves the following steps:

[0069] Based on the relationship between the reconstructed signal and the gas group characteristic function, S2051 obtains the estimated pressure function signal:

[0070] S2052 estimates the patient-side pressure signal based on the pressure signal collected by the gas pressure sensor at the device end and the pressure signal corresponding to the estimated pressure function, thus simultaneously obtaining the estimated patient-side pressure.

[0071] According to the embodiment, in S207, 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. Specifically, the estimated patient-end pressure signal is compared with the target signal in real time, and this is used as a feedback pressure signal for closed-loop regulation of the system pressure. In the closed-loop control system, a specific control algorithm (such as proportional-integral-derivative algorithm, fuzzy control algorithm, or adaptive control algorithm) is used to process the feedback signal and output an error signal to the control unit to adjust the ventilator's fan speed output.

[0072] According to the embodiment, the reconstruction function is obtained based on the reconstruction observer. In actual operating conditions, the actual gas flow rate will not remain constant over a periodic period; there will be abrupt changes. Referring to Figure 3, the flow rate function Q is collected... s Shift the time state to the left by (t1+t2) to obtain the reconstructed flow function. Its expression is:

[0073] That is, to reconstruct the signal The flow signal Q is collected by the flow sensor.s Observe the change in the difference between two values ​​while they are in the same phase. To determine the refactoring function Is it invalid? The calculation formula is:

[0074] Calculate the absolute value of the flow difference between the reconstructed signal and the acquired flow signal.

[0075] By setting the deviation threshold Q k The function used to determine which pressure control method to apply is as follows:

[0076] Where u is a transition factor, used in situations where there is a sudden change in flow rate. To estimate the pressure signal value, To reconstruct the absolute value of the flow difference between the reconstructed signal and the acquired flow signal, To reconstruct the signal value, Q s This is used to collect flow rate signal values. It is intended to ensure a smooth transition in pressure control during sudden changes in flow rate.

[0077] According to the embodiment, if the previous time t i-1 The next one is The transition factor depends on the previous time step. and this moment t i of The ratio k,

[0078] The rules for selecting values ​​are as follows:

[0079] According to the embodiment, determining whether the reconstruction function has failed also includes:

[0080] when When the reconstructed flow function is valid, the estimated pressure function is...

[0081] when When the reconstructed flow function fails, the estimated pressure function is used.

[0082] Therefore, the beneficial effects of the ventilator inlet pressure control in this application include:

[0083] 1. A function reconstructed from real-time sampled flow signals is used for advance prediction, and phase compensation is used to offset the feedback delay caused by the actuator;

[0084] 2. Pressure control based on signal reconstruction takes into account the failure judgment of the reconstruction function, so as to ensure that the pressure control can smoothly transition in the event of sudden changes in flow.

[0085] 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.

[0086] 4. A method for selecting the prediction time of the reconstructed signal to achieve the response of pressure control. In practical applications, pressure control is mostly achieved using motors or valves. Such control requires a certain response time, which is confirmed by confirming that the phase shift time meets the system requirements.

[0087] 5. The application of signal reconstruction observers in pressure control enables pressure control with better tracking effect, and reduces the cost of modifying ventilator equipment compared to structural modification.

[0088] According to an embodiment of this application, a device 400 for controlling the intake pressure of a ventilator is also provided. The device 400 includes: a flow acquisition module 401, a reconstructed signal module 403, a patient end pressure estimation module 405, and a control module 407.

[0089] Referring to Figure 4, the flow acquisition module 401 is used to acquire the flow signal collected by the gas flow sensor and generate the acquisition flow function.

[0090] The reconstructed signal module 403 is used to generate a reconstructed signal by reconstructing the time-domain signal based on the acquired flow function. The module obtains the acquired flow function and the actual flow function of the system, calculates the first phase delay, sets the second phase delay, and generates the reconstructed signal by reconstructing the signal based on the sum of the first phase delay and the second phase delay.

[0091] The patient-side pressure estimation module 405 is used to obtain an estimated patient-side pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor.

[0092] The control module 407 is used to control the fan speed based on the estimated patient end pressure signal as a feedback signal for closed-loop regulation of the intake pressure.

[0093] Preferably, the reconstructed signal module 403 further includes a logic judgment module 4031, used to determine whether the reconstructed signal has failed, calculate the absolute value of the difference between the reconstructed signal and the acquired flow signal, and set a deviation threshold.

[0094] Compared with the absolute value, the corresponding estimated pressure signal is selected, and the piecewise function is as follows:

[0095] when When the reconstructed signal is valid, the pressure signal is estimated.

[0096] when When the reconstructed signal fails, the pressure signal is estimated.

[0097] Where u is a transition factor, used to adjust Q in the event of a sudden change in flow rate. k To set a deviation threshold, To estimate the pressure signal, To reconstruct the absolute value of the difference between the signal and the acquired flow signal, To reconstruct the signal, Q s This is for acquiring quantity signals.

[0098] Embodiments of the present invention may also provide a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the various steps in the above method embodiments can be implemented.

[0099] The processor can be a central processing unit (CPU). The processor can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips.

[0100] 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 button blocking method of the vehicle display device in this embodiment of the invention. The processor executes various functional applications and data processing by running the non-transitory software programs, instructions, and modules stored in the memory.

[0101] The memory may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the processor, etc. Furthermore, the memory may include high-speed random access memory and non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory may optionally include memory remotely located relative to the processor, which can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0102] The one or more modules are stored in the memory, and when executed by the processor, they perform the method described in this embodiment.

[0103] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the aforementioned edge computing server deployment method. The computer-readable storage medium can be a tangible storage medium, such as random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, floppy disks, hard disks, removable storage disks, CD-ROMs, or any other form of storage medium known in the art.

[0104] Those skilled in the art will understand 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 both. Whether implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention. When implemented in hardware, it can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this invention are programs or code segments used to perform the desired tasks. The programs or code segments can be stored in a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried in a carrier wave.

[0105] It should be clarified that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are 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. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of the present invention.

[0106] In this 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 or in place of features of other embodiments.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0108] 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 it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for controlling the inlet pressure of a ventilator, characterized in that, The method includes the following steps: Acquire the flow signal collected by the gas flow sensor and generate the acquisition flow function; Based on the aforementioned acquisition flow function, a reconstructed signal is generated through time-domain signal reconstruction; Based on the reconstructed signal and the pressure signal collected by the pressure sensor, the estimated pressure signal at the patient end is obtained; The estimated patient-side 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 step of generating a reconstructed signal by reconstructing the signal based on the acquired quantity function includes the following steps: Obtain the collected flow function and the actual system flow function, and calculate the first phase delay; Set a second phase delay; Based on the sum of the first phase delay and the second phase delay, a reconstructed signal is generated through signal reconstruction.

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

4. The method according to claim 1, characterized in that, Based on the reconstructed signal and the pressure signal collected by the pressure sensor, an estimated patient-end pressure signal is obtained, preceded by the following steps: Determine whether the reconstructed signal is invalid.

5. The method according to claim 3, characterized in that, The determination of whether the reconstructed signal is invalid includes: Calculate the absolute value of the difference between the reconstructed signal and the acquired flow signal; By comparing the set deviation threshold 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... Where u is a transition factor, used to adjust Q in the event of a sudden change in flow rate. k To set a deviation threshold, The estimated pressure signal, The absolute value of the difference between the reconstructed signal and the acquired flow signal. For the reconstructed signal, Q s The acquired signal is referred to as "the acquired signal".

6. The method according to claim 5, characterized in that, The rules for determining the value of the transition factor u are as follows: The transition factor u depends on the previous time step. and this moment t i of The ratio k, where i is greater than 1, 7. A ventilator inlet pressure control system, characterized in that, The control system includes: The flow acquisition module is used to acquire the flow signal collected by the gas flow sensor and generate the acquisition flow function; The reconstructed signal module is used to generate a reconstructed signal by reconstructing the time-domain signal according to the acquired flow function, wherein the acquired flow function and the actual system flow function are obtained, a first phase delay is calculated, a second phase delay is set, and a reconstructed signal is generated by reconstructing the signal according to the sum of the first phase delay and the second phase delay. The patient-end pressure estimation module is used to obtain an estimated patient-end pressure signal based on the reconstructed signal and the pressure signal collected by the pressure sensor. The control module is used to control the fan speed based on 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 further includes a logic judgment module, used to determine whether the reconstructed signal is invalid, calculate the absolute value of the difference between the reconstructed signal and the acquired flow signal, compare the absolute value with a set deviation threshold, and select the corresponding estimated pressure signal. 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... Where u is a transition factor, used to adjust Q in the event of a sudden change in flow rate. k To set a deviation threshold, The estimated pressure signal, The absolute value of the difference between the reconstructed signal and the acquired flow signal. For the reconstructed signal, Q s The acquired signal is referred to as "the acquired signal".

9. The control system according to claim 8, characterized in that, The rules for determining the value of the transition factor u are as follows: The transition factor u depends on the previous time step. and this moment t i of The ratio k, 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 the processor, they implement the steps of the method described in claims 1-6.

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