A portable emergency ventilator and control method thereof

Abstract

The present disclosure belongs to the technical field of medical devices, and specifically relates to a portable emergency ventilator and a control method thereof, comprising: a direct current brushless fan, an air inlet of which is connected to an air-oxygen mixer, and an air outlet of which is connected to one end of an automatic ball valve; a first connecting pipeline, one end of which is connected to one end of the automatic ball valve away from the brushless fan side, and the other end of which is connected to a flow sensor; a second connecting pipeline, which is connected to the first connecting pipeline through the flow sensor, and a pressure sensor is arranged on the second connecting pipeline; and a controller, which is electrically connected to the direct current brushless fan, the automatic ball valve, the flow sensor and the pressure sensor, respectively.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a portable emergency ventilator and a control method thereof. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] Cardiac arrest (CA) refers to the sudden cessation of cardiac ejection function, the disappearance of large artery pulsation and heart sounds, and severe ischemia and hypoxia of important organs, leading to the end of life. CA is one of the important causes of death in patients, and the survival rate is low, and the survival rate of out-of-hospital cardiac arrest (OHCA) is further reduced. Cardiopulmonary resuscitation (CPR) is an important means of treating cardiac arrest, which generally consists of electric defibrillation, cardiopulmonary resuscitation and respiratory ventilation.

[0004] For respiratory ventilation, professional medical ventilators and emergency airbags can be relied on during the cardiopulmonary process in the hospital. However, in OHCA, professional ventilators are too large and rely on the hospital oxygen supply system, so they cannot be used, so artificial ventilation is often used instead of mechanical ventilation. However, artificial ventilation requires high professional knowledge of the operator and cannot guarantee the accurate delivery of tidal volume. Over-ventilation can cause barotrauma and affect the prognosis, while under-ventilation can cause hypercapnia, affecting the quality of cardiopulmonary resuscitation and reducing the survival rate.

[0005] According to the inventors, there are few portable ventilators with volume-controlled ventilation for CPR, and the control of airway flow is more difficult than pressure control, which makes the actual tidal volume of the ventilator and the preset tidal volume differ greatly, and the tidal volume is uncertain. Therefore, there are few ventilators that can be used for out-of-hospital cardiopulmonary resuscitation. In addition, the titration process of portable ventilators is too long, often requiring four to five ventilator cycles, making the 30:2 ventilation strategy for cardiopulmonary resuscitation difficult to implement. Often, the ventilation during the two to three compression pauses after the ventilator is started is ineffective ventilation, and the ventilation volume does not reach the lung dead zone volume. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a portable emergency ventilator and a control method thereof, which selects and uses a centrifugal fan that is more suitable for CPR, provides a larger gas flow rate under lower airway pressure, and avoids the occurrence of barotrauma during CPR; it provides new ideas for the design of a new portable emergency ventilator for CPR during OHAC, and has important guiding significance for emergency treatments such as cardiopulmonary resuscitation.

[0007] According to some embodiments, a first solution of the present disclosure provides a portable emergency ventilator, which adopts the following technical solution:

[0008] A portable emergency ventilator, comprising:

[0009] A DC brushless fan, the air inlet of which is connected to the air-oxygen mixer, and the air outlet of which is connected to one end of the automatic ball valve;

[0010] A first connecting pipeline, one end of which is connected to one end of the automatic ball valve far away from the brushless fan side, and the other end of which is connected to the flow sensor;

[0011] a second connecting pipeline, connected to the first connecting pipeline through the flow sensor, and a pressure sensor is provided on the second connecting pipeline;

[0012] The controller is electrically connected to the brushless DC fan, the automatic ball valve, the flow sensor and the pressure sensor respectively.

[0013] As a further technical limitation, the portable emergency ventilator also includes a power supply unit electrically connected to the controller, the DC brushless fan, the automatic ball valve, the flow sensor and the pressure sensor respectively.

[0014] As a further technical limitation, the automatic ball valve includes a motor, a first bearing, a first valve body, a valve core, a second valve body, a second bearing and an angle sensor; the valve core is fixed in the first valve body and the second valve body through the first bearing and the second bearing, the motor is connected to the valve core through the first bearing, and the angle sensor is connected to the valve core through the second bearing.

[0015] Furthermore, the motor is connected to an air outlet of the DC brushless fan, and the angle sensor is connected to the first connecting pipeline.

[0016] Furthermore, the motor is connected to the valve core to provide power for the rotation of the valve core, thereby realizing the opening and closing of the first connecting pipeline; the angle sensor is connected to the valve core to obtain the rotation angle of the valve core in real time, and the obtained valve core angle is fed back to the controller, and combined with the pressure sensor and the flow sensor, a closed-loop control system of the valve core is formed, and the motor is adjusted in real time to make the valve core rotate to an appropriate angle.

[0017] Furthermore, in the closed-loop control system, the flow sensor obtains the flow from the first connecting pipeline to the second connecting pipeline in real time, and feeds back the real-time data to the controller; the controller controls the DC brushless fan in real time in combination with the real-time data and the preset flow data, and completes the real-time adjustment of the flow of the portable emergency ventilator; based on the real-time control of the DC brushless fan and the real-time monitoring of the flow sensor, the motor is adjusted under the action of the controller to control the rotation angle of the automatic ball valve, thereby realizing the control of the opening and closing state of the automatic ball valve.

[0018] According to some embodiments, a second solution of the present disclosure provides a control method for a portable emergency ventilator, which adopts the following technical solution:

[0019] A control method for a portable emergency ventilator, comprising:

[0020] Acquire real-time data from pressure sensors and flow sensors to obtain the initial flow and ventilation frequency of the portable emergency ventilator;

[0021] According to the obtained initial flow and ventilation frequency, the DC brushless fan is adjusted in real time in combination with the controller to achieve real-time adjustment of the portable emergency ventilator.

[0022] As a further technical limitation, in the process of real-time adjustment of the DC brushless fan in combination with the controller, a wavelet transform optimization PID control method, namely, the MR-PID control algorithm, is adopted; based on the MR-PID control algorithm, under the action of the controller, the input signal is divided into a low-scale signal for eliminating noise, a medium-scale signal for increasing damping, and a high-scale signal for eliminating high-frequency distortion. These three signals are combined to generate a smooth control signal to realize real-time adjustment of the portable emergency ventilator.

[0023] As a further technical limitation, the real-time adjustment of the portable emergency ventilator includes respiratory rate adjustment and respiratory flow adjustment;

[0024] During the respiratory rate adjustment process, the rotation angle of the valve core is obtained in real time through the angle sensor, and the obtained valve core angle is fed back to the controller. In combination with the pressure sensor and the flow sensor, a closed-loop control system of the valve core is formed, and the motor is adjusted in real time to control the rotation angle of the automatic ball valve so that the valve core rotates to a suitable angle, and the opening and closing state of the automatic ball valve is controlled to achieve the adjustment of the respiratory rate of the portable emergency ventilator;

[0025] During the respiratory flow regulation process, the flow from the first connecting pipeline to the second connecting pipeline is obtained in real time through the flow sensor, and the real-time data is fed back to the controller. Combined with the real-time monitoring data of the pressure sensor and the flow sensor, the DC brushless fan is adjusted in real time to adjust the flow at the air inlet of the DC brushless fan, thereby completing the regulation of the respiratory flow of the portable emergency ventilator.

[0026] As a further technical limitation, during the real-time adjustment of the portable emergency ventilator, the ST titration method is used to construct a linear relationship between the PWM of the DC brushless fan and the maximum airway flow of the portable emergency ventilator, predict the initial PWM, and improve the titration speed of the portable emergency ventilator.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention provides a portable emergency ventilator based on volume control. The portable emergency ventilator has a simple structure and a compact size. A blower with low airway pressure and high flow is used as a gas pressurization source, which is more suitable for emergency treatment during CPR and avoids barotrauma. A control method of a brushless DC motor is used to achieve precise control of the flow of the portable emergency ventilator. At the same time, a new ST titration method is used, which is simple and effective, and the titration process can be completed using two ventilations, thereby greatly shortening the titration time. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings constituting a part of the present disclosure are used to provide a further understanding of the present disclosure. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure.

[0030] Figure 1 is a schematic structural diagram of a portable emergency ventilator in Embodiment 1 of the present disclosure;

[0031] Figure 2 is a schematic structural diagram of the automatic ball valve in the first embodiment of the present disclosure;

[0032] Figure 3 is a structural block diagram of a control method for a portable emergency ventilator in Embodiment 2 of the present disclosure;

[0033] Figure 4 It is a structural block diagram of a control system for respiratory frequency and respiratory flow of a portable emergency ventilator in the second embodiment of the present disclosure;

[0034] Figure 5 is a structural block diagram of the MR-PID algorithm in the second embodiment of the present disclosure;

[0035] Figure 6 is a structural block diagram of the ST titration method in the second embodiment of the present disclosure;

[0036] Among them, 1. the first connecting pipeline; 2. the automatic ball valve; 21. the first bearing; 22. the first valve body; 23. the second valve body; 24. the angle sensor; 25. the second bearing; 26. the valve core; 27. the motor; 3. the air-oxygen mixer; 4. the DC brushless fan; 5. the controller; 6. the power supply unit; 7. the flow sensor; 8. the pressure sensor; 9. the second connecting pipeline. DETAILED DESCRIPTION

[0037] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments.

[0038] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present disclosure. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present disclosure belongs.

[0039] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0040] In the present disclosure, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present disclosure, and do not specifically refer to any part or element in the present disclosure and should not be understood as limitations on the present disclosure.

[0041] In the present disclosure, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present disclosure can be determined according to specific circumstances, and they cannot be understood as limitations on the present disclosure.

[0042] In the absence of conflict, the embodiments in the present disclosure and the features in the embodiments may be combined with each other.

[0043] Embodiment 1

[0044] Embodiment 1 of the present disclosure introduces a ventilator and designs a novel portable emergency ventilator. A DC brushless fan is used to provide the required ventilation volume, a flow sensor is used to capture the airway flow, and a microprocessor is used to send a pulse width modulation (PWM) signal to feedback adjust the speed of the DC brushless fan to complete a constant volume ventilation mode; an automatic ball valve is used to achieve frequency adjustment of the portable emergency ventilator and improve the response speed of the portable emergency ventilator; a simple air-oxygen mixer is used to complete the mixing of air and oxygen to meet the preset oxygen content requirement.

[0045] like Figure 1 A portable emergency ventilator is shown, comprising a first connecting pipeline 1, an automatic ball valve 2, an air-oxygen mixer 3, a DC brushless fan 4, a controller 5, a power supply unit 6, a flow sensor 7, a pressure sensor 8 and a second connecting pipeline 9; the gas power of the portable emergency ventilator comes from the DC brushless fan 4, and the PWM signal is used for speed regulation to control the flow rate of the DC brushless fan 4 outlet. The outlet of the DC brushless fan 4 is connected to the automatic ball valve 2, and the automatic ball valve 2 completes the opening and closing of the first connecting pipeline 1 to control the breathing frequency. The air inlet of the DC brushless fan 4 is connected to the simple air-oxygen mixer 3 to achieve the mixing of oxygen and air. The automatic ball valve 2 is connected to the air inlet of the flow sensor 7 through the first connecting pipeline 1, so that the flow sensor 7 monitors the airway flow in real time, the outlet of the flow sensor 7 is connected to the second connecting pipeline 9, and the pressure sensor 8 is connected to the second connecting pipeline 9 to capture the pressure in the airway in real time. The controller 5 is used to receive data from the flow sensor 7 and the pressure sensor 8, and to perform feedback control on the DC brushless fan 4 to ensure the provision of a constant flow rate. The power supply unit 6 provides the 24V voltage required by the flow sensor 7, the 5V voltage required by the pressure sensor 8 and the controller 5, and the 12V voltage required by the automatic ball valve 2.

[0046] like Figure 2 As shown, the automatic ball valve 2 includes a first bearing 21, a first valve body 22, a second valve body 23, an angle sensor 24, a second bearing 25, a valve core 26 and a motor 27; wherein the valve core 23 is fixed in the first valve body 22 and the second valve body 23 through the first bearing 21 and the second bearing 25, the motor 27 is connected to the valve core 26 through the first bearing 21, and the angle sensor 24 is connected to the valve core 26 through the second bearing 25; the motor 27 is connected to the air outlet of the DC brushless fan 4, and the angle sensor 24 is connected to the first connecting pipeline 1.

[0047] The frequency of the portable emergency ventilator is controlled by the automatic ball valve 2 and the DC brushless fan 4. The valve body is composed of an upper valve body 2 and a lower valve body 3. The valve core 6 is installed in the valve body. The valve core 6 is fixed in the valve body by a first bearing 1 and a second bearing 5. The bearings ensure the free rotation of the valve core; the motor 7 provides power for the rotation of the valve core 6, so that the valve core 6 rotates to open and close the pipeline; the angle sensor 4 is connected to the valve core 6 to obtain the rotation angle of the valve core 6; the angle sensor 4 and the micro stepping motor 7 form a closed-loop system to ensure that the valve core rotates to the correct angle.

[0048] During the use of the portable emergency breathing machine, the motor 27 is connected to the valve core 26 to provide power for the valve core 26 to rotate, thereby realizing the opening and closing of the first connecting pipeline 1; the angle sensor 24 is connected to the valve core 26 to obtain the rotation angle of the valve core 26 in real time, and the obtained angle of the valve core 26 is fed back to the controller 5, and combined with the pressure sensor 8 and the flow sensor 7, a closed-loop control system of the valve core 26 is formed, and the motor 27 is adjusted in real time so that the valve core 26 rotates to a suitable angle; in the closed-loop control system, the flow sensor 7 obtains the flow from the first connecting pipeline 1 to the second connecting pipeline 9 in real time, and feeds back the real-time data to the controller 5; the controller 5 controls the DC brushless fan 4 in real time in combination with the real-time data and the preset flow data, and completes the real-time adjustment of the flow of the portable emergency breathing machine; according to the real-time control of the DC brushless fan 4, combined with the real-time monitoring of the flow sensor 7, the motor is adjusted under the action of the controller 5 to control the rotation angle of the automatic ball valve 2, thereby realizing the control of the opening and closing state of the automatic ball valve 2.

[0049] Embodiment 2

[0050] Based on the portable emergency ventilator introduced in the first embodiment, the second embodiment of the present disclosure introduces a control method for the portable emergency ventilator. The input signal noise is eliminated by a multi-resolution proportional-integral-derivative (MR-PID) algorithm to complete the real-time control of the airway flow of the portable emergency ventilator; the coordinated work of the DC brushless fan and the automatic ball valve is used to complete the precise control of the respiratory frequency, inhalation time and exhalation time; the ST titration method is used to enable the portable emergency ventilator to complete the titration process with fewer ventilation times. The optimal initial PWM value can be predicted by the flow parameters and PWM parameters of the first two times, so that the initial flow reaches the preset flow, the titration time is reduced, and the titration speed of the portable emergency ventilator is improved.

[0051] like Figure 3The control method of a portable emergency ventilator shown includes controlling the system flow and respiratory frequency, the portable emergency ventilator obtaining the initial flow and ventilation frequency, obtaining the initial PWM value through ST titration, driving the DC brushless fan, and the portable emergency ventilator entering the inhalation phase after the automatic ball valve is opened. The portable emergency ventilator records the flow and time parameters in real time during the ventilation process, and judges whether the inhalation time has been reached. If the intake time has not been reached, it will judge whether the target flow has been reached. If the target flow has not been reached, the portable emergency ventilator will adjust the PWM value to control the outlet flow of the DC brushless fan; after the intake time has been reached, the portable emergency ventilator will jump out of the inhalation phase and enter the exhalation phase, close the automatic ball valve, and at the same time, the DC brushless fan accepts the exhalation PWM to reduce the speed. When the exhalation time reaches the preset exhalation time, the portable emergency ventilator enters the exhalation phase again.

[0052] like Figure 4 The control structure block diagram of the inhalation flow and respiratory frequency of the portable emergency ventilator shown in the figure reads the flow of the portable emergency ventilator through the flow sensor, and feeds back the actual flow Fr to the controller. The controller compares the actual flow Fr with the preset flow Fs to complete the real-time control of the PWM value required by the DC brushless fan, thereby adjusting the flow of the portable emergency ventilator in real time. The respiratory frequency adjustment of the portable emergency ventilator is completed by controlling the inhalation time and exhalation time of the portable emergency ventilator; the actual ventilation time parameters including the intake time and the exhalation time Tr are read by the DC brushless fan, and the controller compares and judges the actual time Tr with the preset time Ts and realizes the opening and closing of the automatic ball valve. The automatic ball valve has its own feedback system to ensure that the valve is fully opened and fully closed.

[0053] In this embodiment, the brushless DC fan adopts the MR-PID control method, and uses wavelet transform on the PID algorithm to optimize the PID control to achieve accurate control of the pre-reference flow.

[0054] The multi-resolution property of wavelet transform has good resolution in both time and frequency domains. It is a hierarchical representation of a signal or function in the form of successive approximations at different scales. Each approximation is a smoothed version of the original signal. Error decomposition allows capturing detailed information of different frequencies depending on the number of decomposition levels. In the MR-PID controller, the multi-resolution property of wavelets is utilized to decompose the error signal into a linear combination of basis functions consisting of the mother wavelet and its expansion and translation, which has good resolution in both time and frequency domains.

[0055] like Figure 5The MR-PID control method shown uses wavelet transform to separate the error signal into high, medium and low frequencies. The increase in gain corresponding to the high-frequency signal improves the interference suppression of the device. The medium-frequency signal adds damping in the device to improve its transient characteristics, and the low-frequency signal eliminates noise by adjusting the noise to zero. By combining these three, a smooth control signal can be generated to meet the required characteristics.

[0056] exist Figure 5 In the equation, R, Y and e are the reference signal, output signal and error signal respectively. The error signal e is taken as a linear combination of orthogonal functions, decomposed into its components by wavelet, and then transformed and combined to generate the control signal u. The error signal is decomposed into high and low repetitive parts at a certain decomposition level.

[0057] The low-frequency error decomposition components are:

[0058]

[0059] The error decomposition components of the intermediate frequency are:

[0060]

[0061] The high-frequency error decomposition components are:

[0062]

[0063] Where N is the number of levels, and n and k are sets of integers.

[0064] The filters h[k] and g[k] are specific descriptions of the selected wavelet functions. The MR-PID controller uses three gain parameters K at high, medium and low frequencies. H , K M , K L . K M There are further sub-gains at different frequencies located between the highest frequency and the lowest frequency, depending on the decomposition level and the desired accuracy. More decomposition levels increase the number of these sub-gains. However, since three gains are involved, at least two levels of decomposition are required. In the patent, two levels of decomposition are used because their application brings good results. However, more levels may be used for higher accuracy, but at the cost of higher computational complexity.

[0065] In terms of frequency, the proportional and integral terms are used to capture low-frequency signals, while the derivative term is used to capture high-frequency signals. In the MR-PID controller, the error signal is decomposed into its high, low and medium frequencies, namely:

[0066] e(X)=e H (X)+e M1 (X)+…+eM(n-1) (X)+e L (X)

[0067] Each error component is scaled by its own gain to generate the controller output signal u MP-PID , we get:

[0068] u MP-PID =K H e H +K M1 e M1 +…+K M(n-1) e M(n-1) +K L e L

[0069] The control output of the MR-PID controller is a linear combination of different gains, and these components can be scaled by the corresponding gains to produce the control signal.

[0070] This embodiment uses two-level decomposition to obtain a controller with three adjustment parameters. Some interferences in the control process of the motor are low-frequency signals, and the noise generated in the sensor is a high-frequency signal. Compared with the PID controller, the MR-PID controller has better performance. In the multi-resolution decomposition, the signal is divided into low-scale, medium-scale and high-scale error signals. The high-scale signal is used to eliminate high-frequency distortion, and the increase in gain corresponding to the high-scale signal improves the interference suppression of the device. The medium-scale signal increases damping in the device to improve its transient characteristics, and the low-scale signal eliminates noise by adjusting the noise to zero. By combining these three, a smooth control signal can be generated to meet the required characteristics.

[0071] In order to obtain a fast titration of the V-IPPV mode, this embodiment adopts a new ST titration method, which can obtain the optimal initial expiratory PWM value after two complete titration ventilations. Figure 5 As shown, the portable emergency ventilator randomly gives a PWM signal to start the first ventilation. The portable emergency ventilator records the PWM value PWM1 and the maximum actual flow Fr1 of the first ventilation; in the second ventilation, the portable emergency ventilator also records the PWM value of the centrifugal fan as PWM2 and the maximum actual flow Fr2; after two ventilations, the portable emergency ventilator will find the most suitable initial exhalation PWM value Pini through the first two captured PWM1, PWM2, Fr1, and Fr2. The PWM value Pini is used in the exhalation phase of the portable emergency ventilator with the automatic ball valve closed to ensure that the initial flow in the inhalation phase quickly reaches the preset requirements.

[0072] Under fixed PWM, after the portable emergency ventilator is connected to the simulated lung, the maximum airway flow of a single ventilation is proportional to the PWM value. The ST titration method uses the linear relationship between PWM and maximum flow (Pini = (PWM2-PWM1) / (Fs2-Fs1)*(Fs-Fs2)+PWM2), and the ventilation parameters of the first two times can accurately predict the most suitable initial expiratory PWM value Pini.

[0073] This embodiment obtains the initial flow rate and ventilation frequency of the portable emergency ventilator by acquiring real-time data from the pressure sensor and the flow sensor; according to the obtained initial flow rate and ventilation frequency, the DC brushless fan is adjusted in real time in combination with the controller to achieve real-time adjustment of the portable emergency ventilator; wherein the real-time adjustment of the portable emergency ventilator includes respiratory frequency adjustment and respiratory flow adjustment;

[0074] During the process of adjusting the respiratory rate, the rotation angle of the valve core is obtained in real time through the angle sensor, and the obtained valve core angle is fed back to the controller. In combination with the pressure sensor and the flow sensor, a closed-loop control system of the valve core is formed, and the motor is adjusted in real time to control the rotation angle of the automatic ball valve so that the valve core rotates to a suitable angle, and the opening and closing state of the automatic ball valve is controlled to achieve the adjustment of the respiratory rate of the portable emergency ventilator;

[0075] During the process of respiratory flow regulation, the flow from the first connecting pipeline to the second connecting pipeline is obtained in real time through the flow sensor, and the real-time data is fed back to the controller. Combined with the real-time monitoring data of the pressure sensor and the flow sensor, the DC brushless fan is adjusted in real time to adjust the flow at the air inlet of the DC brushless fan, thereby completing the regulation of the respiratory flow of the portable emergency ventilator.

[0076] The above description is only a preferred embodiment of the present disclosure and is not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

[0077] Although the above describes the specific implementation methods of the present disclosure in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present disclosure. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present disclosure, various modifications or variations that can be made by those skilled in the art without creative work are still within the scope of protection of the present disclosure.

Claims

1. A portable emergency ventilator, characterized in that: include: A DC brushless fan, the air inlet of which is connected to the air-oxygen mixer, and the air outlet of which is connected to one end of the automatic ball valve; A first connecting pipeline, one end of which is connected to one end of the automatic ball valve far away from the brushless fan side, and the other end of which is connected to the flow sensor; a second connecting pipeline, connected to the first connecting pipeline through the flow sensor, and a pressure sensor is provided on the second connecting pipeline; A controller, electrically connected to the DC brushless fan, the automatic ball valve, the flow sensor and the pressure sensor respectively; The automatic ball valve comprises a motor, a first bearing, a first valve body, a valve core, a second valve body, a second bearing and an angle sensor; the valve core is fixed in the first valve body and the second valve body through the first bearing and the second bearing, the motor is connected to the valve core through the first bearing, and the angle sensor is connected to the valve core through the second bearing; The automatic ball valve is provided with an angle sensor, which is connected to the valve core, and obtains the rotation angle of the valve core in real time. The obtained valve core angle is fed back to the controller, and combined with the pressure sensor and the flow sensor, a closed-loop control system of the valve core is formed, and the motor is adjusted in real time to make the valve core rotate to a suitable angle; The ventilator adopts wavelet transform optimization PID control method and ST titration method; The ST titration method uses the linear relationship between PWM and maximum flow rate , use the ventilation parameters of the first two times to accurately predict the most suitable initial exhalation PWM value Pini, specifically: the portable emergency ventilator randomly gives a PWM signal to start the first ventilation, and the portable emergency ventilator records the PWM value PWM1 and the maximum actual flow Fr1 of the first ventilation; during the second ventilation, the portable emergency ventilator also records the PWM value of the DC brushless fan as PWM2 and the maximum actual flow Fr2; after two ventilations, the portable emergency ventilator finds the most suitable initial exhalation PWM value Pini based on the PWM1, PWM2, Fr1, and Fr2 captured in the first two times; The PWM value Pini is used in the exhalation phase of a portable emergency ventilator with an automatic ball valve closure to ensure that the initial flow rate in the inhalation phase quickly reaches the preset requirements; The flow rate of the portable emergency ventilator is read through the flow sensor, and the actual flow rate Fr is fed back to the controller. The controller compares the actual flow rate Fr with the preset flow rate Fs to complete the real-time control of the PWM value required by the DC brushless fan, thereby adjusting the flow rate of the portable emergency ventilator in real time; the respiratory frequency adjustment of the portable emergency ventilator is completed by controlling the inhalation time and exhalation time of the portable emergency ventilator; the actual ventilation time parameters including the intake time and the exhalation time Tr are read through the DC brushless fan, and the controller compares and judges the actual time Tr with the preset time Ts and realizes the opening and closing of the automatic ball valve. The automatic ball valve has its own feedback system to ensure that the valve is fully opened and fully closed; The DC brushless fan adopts the MR-PID control method, which uses wavelet transform to optimize the PID control on the PID algorithm to achieve accurate control of the pre-reference flow; R, Y and e are the reference signal, output signal and error signal respectively; the error signal e is taken as a linear combination of orthogonal functions, decomposed into its components by wavelet, and then transformed and combined to generate the control signal u , decompose the error signal into high and low repetitive parts at a certain decomposition level; The low-frequency error decomposition components are: The error decomposition components of the intermediate frequency are: The high-frequency error decomposition components are: in, N is the number of levels, n and k is a set of integers; filters h[k] and g[k] are specific descriptions of the selected wavelet functions; They represent the three gain parameters of the MR-PID controller at high, medium and low frequencies respectively; In terms of frequency, the proportional and integral terms are used to capture low-frequency signals, while the derivative term is used to capture high-frequency signals; in the MR-PID controller, the error signal is decomposed into its high, low and medium frequencies, namely: Each error component is scaled by its own gain to generate the controller output signal , we get: The control output of the MR-PID controller is a linear combination of different gains, and these components are scaled by the corresponding gains to produce the control signal.

2. A portable emergency ventilator as claimed in claim 1, characterized in that: It also includes a power supply unit which is electrically connected to the controller, the DC brushless fan, the automatic ball valve, the flow sensor and the pressure sensor respectively.

3. A portable emergency ventilator as claimed in claim 1, characterized in that: The motor is connected to the air outlet of the brushless DC fan, and the angle sensor is connected to the first connecting pipeline.

4. A portable emergency ventilator as claimed in claim 1, characterized in that: The motor is connected to the valve core to provide power for the valve core to rotate, thereby realizing the opening and closing of the first connecting pipeline.

5. A portable emergency ventilator as claimed in claim 4, characterized in that: In a closed-loop control system, a flow sensor obtains the flow from the first connecting pipeline to the second connecting pipeline in real time, and feeds back the real-time data to a controller; the controller controls the DC brushless fan in real time in combination with the real-time data and the preset flow data, and completes the real-time adjustment of the flow of the portable emergency ventilator; based on the real-time control of the DC brushless fan and the real-time monitoring of the flow sensor, the motor is adjusted under the action of the controller to control the rotation angle of the automatic ball valve, thereby realizing the control of the opening and closing state of the automatic ball valve.

6. A method for controlling a portable emergency ventilator, using the portable emergency ventilator as claimed in any one of claims 1 to 5, characterized in that: include: Acquire real-time data from pressure sensors and flow sensors to obtain the initial flow and ventilation frequency of the portable emergency ventilator; According to the obtained initial flow rate and ventilation frequency, the DC brushless fan is adjusted in real time in combination with the controller to achieve real-time adjustment of the portable emergency ventilator; specifically, in the process of adjusting the DC brushless fan in real time in combination with the controller, a wavelet transform is used to optimize the PID control method, namely, the MR-PID control algorithm; based on the MR-PID control algorithm, under the action of the controller, the input signal is divided into a low-scale signal for eliminating noise, a medium-scale signal for increasing damping, and a high-scale signal for eliminating high-frequency distortion, and these three signals are combined to generate a smooth control signal to achieve real-time adjustment of the portable emergency ventilator; The real-time regulation of the portable emergency ventilator includes respiratory rate regulation and respiratory flow regulation; During the respiratory rate adjustment process, the rotation angle of the valve core is obtained in real time through the angle sensor, and the obtained valve core angle is fed back to the controller. In combination with the pressure sensor and the flow sensor, a closed-loop control system of the valve core is formed, and the motor is adjusted in real time to control the rotation angle of the automatic ball valve so that the valve core rotates to a suitable angle, and the opening and closing state of the automatic ball valve is controlled to achieve the adjustment of the respiratory rate of the portable emergency ventilator; During the respiratory flow adjustment process, the flow from the first connecting pipeline to the second connecting pipeline is obtained in real time through the flow sensor, and the real-time data is fed back to the controller. The DC brushless fan is adjusted in real time in combination with the real-time monitoring data of the pressure sensor and the flow sensor, and the flow at the air inlet of the DC brushless fan is adjusted to complete the respiratory flow adjustment of the portable emergency ventilator; In the process of real-time adjustment of the portable emergency ventilator, the ST titration method is used to construct the linear relationship between the PWM of the DC brushless fan and the maximum airway flow of the portable emergency ventilator, predict the initial PWM, and improve the titration speed of the portable emergency ventilator.

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