A positive and negative pressure airway cleaning system and method based on high-speed switching of a single turbine

Abstract

This invention relates to the field of medical device technology and discloses a positive and negative pressure airway clearing system and method based on high-speed switching of a single turbine. The processing module receives feedback signals from sensing components and compares these signals with preset target pressure or flow parameters to generate electronic control signals. The control unit is configured to output electronic control signals to the electric turbine fan via a drive module. This design significantly reduces the complexity, size, weight, and manufacturing cost of the equipment by using a single high-performance turbine fan instead of the traditional dual-turbine and complex valve system. The pressure generation unit and control unit work together to achieve millisecond-level switching of the electric turbine fan's operating state, enabling rapid and smooth alternation of positive and negative pressure, thereby generating a highly efficient pressure waveform that closely resembles that of a physiological cough.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a positive and negative pressure airway clearing system and method based on high-speed switching of a single turbine. Background Technology

[0002] In intensive care, emergency departments, and respiratory medicine departments, effectively clearing deep airway secretions from patients with artificial airways is crucial for maintaining respiratory function, preventing pulmonary infections, and reducing mortality. Artificial airways include endotracheal intubation and tracheotomy. Pulmonary infections can specifically manifest as ventilator-associated pneumonia. Currently, there are three main treatment options in clinical practice.

[0003] Routine suctioning, as a basic nursing procedure, involves nurses inserting a suction catheter into the patient's airway through an endotracheal tube and performing blind suction based on touch and experience. However, this procedure lacks visual guidance, easily irritating the airway mucosa and causing damage, bleeding, or spasm. Secondly, the depth of clearance is limited, only able to remove sputum in the main airway, making it difficult to clear deep sputum accumulated in the bronchi, bronchioles, and alveoli. Moreover, the procedure requires disconnecting the ventilator, leading to interruption of ventilation and a drop in blood oxygen saturation, posing a very high risk to patients with hemodynamic instability.

[0004] Mechanical expectorants work by first injecting gas into the lungs to create positive pressure, then rapidly generating negative pressure to suction, loosening sputum in the peripheral small airways and guiding it to the main airway. Most commercially available expectorants employ a dual-turbine system with complex solenoid valves to achieve alternating positive and negative pressure. The working principle involves one turbine specifically generating positive pressure and another specifically generating negative pressure, switching the airway via a sophisticated solenoid valve network to direct either positive or negative pressure to the patient. However, this system is complex and expensive. The dual-turbine, multi-valve, and complex piping design results in a large overall size, leading to high manufacturing and maintenance costs. Furthermore, it suffers from response delays and significant pressure fluctuations. Airway switching relies on the physical action of mechanical valves, with response times on the order of hundreds of milliseconds. The transition between positive and negative pressure is slow and difficult to be smooth, failing to generate an ideal and precise cough waveform and impacting sputum expectoration efficiency.

[0005] Fiberoptic bronchoscopy suctioning allows for visualized deep bronchial suctioning and is a clinically recognized method for this purpose. However, it is essentially a mechanical removal of sputum from the large airways and cannot effectively loosen sputum in the alveoli and small airways. Furthermore, the equipment is expensive, requires a high level of expertise to operate, involves a complex sterilization process, and can impede airflow during the procedure, affecting the patient's ventilation.

[0006] The existing patent publication number CN219071651U describes a breathing and sputum-clearing integrated machine that provides a physical integration solution for breathing and sputum clearing. However, it uses two independent power sources and a shut-off valve switching mode, which makes the system cumbersome and unable to achieve high-speed seamless pressure switching.

[0007] The existing patent publication number CN112274742A describes a cough device and control method based on a positive and negative pressure electromagnetic regulating valve. It relies on the complex mechanical structure of the positive and negative pressure electromagnetic regulating valve for airway guidance and switching. The response speed and reliability are limited by the physical characteristics of the mechanical valve. Summary of the Invention

[0008] The main objective of this invention is to provide a positive and negative pressure airway clearing system based on high-speed switching of a single turbine, aiming to improve the shortcomings of the prior art and solve the problem that traditional suction devices rely on mechanical valves for airway switching, which are limited by the physical inertia and action time of the valve core, resulting in high delay in positive and negative pressure switching and insufficient steepness of the pressure waveform switching.

[0009] To achieve the above objectives, this invention proposes a positive and negative pressure airway cleaning system based on high-speed switching of a single turbine, comprising: A pressure generation unit includes an electric turbine fan and a sensing component disposed at the air output end of the electric turbine fan. The electric turbine fan is configured to switch between forward and reverse rotation to generate positive and negative airflow respectively. The sensing component is used to detect the pressure and flow parameters at the air output end. The control unit is electrically connected to the pressure generating unit. The control unit includes a processing module and a drive module coupled thereto. The drive module is used to drive the electric turbine fan to operate. The airway interface unit includes an airway tube connected to the patient's airway and a human-computer interaction interface for parameter setting and mode selection. The processing module receives feedback signals from the sensing components and compares the feedback signals with preset target pressure or flow parameters to generate electronic control signals. The control unit is configured to output the electronic control signals to the electric turbine fan through the drive module.

[0010] Optionally, the electric turbine fan is a brushless DC centrifugal fan.

[0011] Optionally, the sensing component includes: A bidirectional differential pressure sensor is used to measure the real-time pressure at the output end of the gas path; A thermal mass flow meter is used to measure the real-time flow rate at the output end of the gas path.

[0012] Optionally, the processing module is a digital signal processor, and the drive module is connected to the three-phase winding of the electric turbine fan, used to convert the space vector pulse width modulation signal generated by the processing module into a three-phase AC signal to drive the electric turbine fan.

[0013] Optionally, the gas interface unit further includes: An air intake filter is disposed at the air intake end of the electric turbine fan; A silencer, wherein the silencer is disposed inside the air passage pipe; A ventilator tubing interface is located at the outlet end of the airway tubing and is used to connect to the patient's endotracheal tube.

[0014] Optionally, the human-machine interface includes a touch screen or physical buttons, and the human-machine interface is configured to receive parameter settings from the user for working mode, positive pressure value, negative pressure value, pressure duration and number of cycles.

[0015] Furthermore, this application also provides a method for cleaning positive and negative pressure air passages based on high-speed switching of a single turbine, employing the aforementioned positive and negative pressure air passage cleaning system. The method includes the following steps: The target pressure parameters or working mode can be set through the human-computer interaction interface; The control unit generates corresponding electronic control signals based on the selected mode and parameters; The drive module drives the electric turbine fan to run at the target speed and direction according to the electronic control signal; The sensing component monitors the pressure and flow rate at the gas output end in real time and feeds them back to the control unit. The control unit adjusts the electronic control signal in real time based on the deviation between the feedback signal and the target parameter, so as to achieve closed-loop control of the output pressure.

[0016] Optionally, the drive module drives the electric turbine fan to operate at a target speed and direction according to the electronic control signal, including the following steps: At the end of the previous pressure period, the control unit applies a reverse voltage vector to the electric turbine fan through the drive module, causing the electric turbine fan to enter a regenerative braking state to decelerate. The rotational speed of the electric turbine is monitored. When the rotational speed is lower than a preset threshold, a reverse drive voltage vector is applied to accelerate the electric turbine in the opposite direction to the target rotational speed.

[0017] Optionally, when the operating mode is active sputum clearance mode, the positive and negative pressure airway clearance method includes executing at least one sputum clearance sequence, each sputum clearance sequence including: The electric turbine fan is controlled to rotate forward to inflate the patient's lungs with a first preset positive pressure for a first preset time. Within 200 milliseconds, the electric turbine fan is controlled to switch from forward rotation to reverse rotation, drawing air from the patient's airway with a second preset negative pressure, and continuing for a second preset time.

[0018] Optionally, the positive and negative pressure airway clearing method further includes an intelligent collaborative control step: When the positive and negative pressure airway clearing system is used in conjunction with the mechanical ventilation equipment, the control unit monitors the patient's respiratory phase status in real time. When the patient is determined to have entered the expiratory phase, the processing module adjusts the control target of the electric turbine fan to maintain a constant auxiliary negative pressure to help the patient expel airway secretions. When the expiratory phase is detected to have ended and the patient has entered the inspiratory phase, the processing module will restore the control target to the preset pressure or flow parameters required for mechanical ventilation.

[0019] Beneficial Effects: The positive and negative pressure airway clearing system based on high-speed switching of a single turbine proposed in this invention includes a pressure generation unit, a control unit, and an airway interface unit. The pressure generation unit includes an electric turbine and a sensing component disposed at the airway output end of the electric turbine. The electric turbine is configured to switch between forward and reverse rotation to generate positive and negative airflow respectively. The sensing component is used to detect the pressure and flow parameters at the airway output end. The control unit is electrically connected to the pressure generation unit and includes a processing module and a drive module coupled thereto. The drive module is used to drive the electric turbine. The airway interface unit includes an airway pipe communicating with the patient's airway and a human-machine interface for parameter setting and mode selection. The processing module receives feedback signals from the sensing component and compares the feedback signals with preset target pressure or flow parameters to generate electronic control signals. The control unit is configured to output electronic control signals to the electric turbine through the drive module. This design allows for the replacement of traditional dual-turbine and complex valve systems with a single high-performance turbine fan, significantly reducing the complexity, size, weight, and manufacturing cost of the equipment. The pressure generation unit and control unit work together to achieve millisecond-level switching of the electric turbine fan's operating state, enabling rapid and smooth alternation of positive and negative pressure, thereby generating a highly efficient pressure waveform that closely resembles a physiological cough. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0021] Figure 1 This is a structural block diagram of the positive and negative pressure airway clearing system disclosed in this application; Figure 2 This is a flowchart of the positive and negative pressure airway cleaning system disclosed in this application; Figure 3 This is a flowchart of the positive and negative pressure airway cleaning method disclosed in this application.

[0022] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0024] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0025] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0026] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0027] In intensive care, emergency departments, and respiratory medicine departments, effectively clearing deep airway secretions from patients with artificial airways is crucial for maintaining respiratory function, preventing pulmonary infections, and reducing mortality. Artificial airways include endotracheal intubation and tracheotomy. Pulmonary infections can specifically manifest as ventilator-associated pneumonia. Currently, there are three main treatment options in clinical practice.

[0028] Routine suctioning, as a basic nursing procedure, involves nurses inserting a suction catheter into the patient's airway through an endotracheal tube and performing blind suction based on touch and experience. However, this procedure lacks visual guidance, easily irritating the airway mucosa and causing damage, bleeding, or spasm. Secondly, the depth of clearance is limited, only able to remove sputum in the main airway, making it difficult to clear deep sputum accumulated in the bronchi, bronchioles, and alveoli. Moreover, the procedure requires disconnecting the ventilator, leading to interruption of ventilation and a drop in blood oxygen saturation, posing a very high risk to patients with hemodynamic instability.

[0029] Mechanical expectorants work by first injecting gas into the lungs to create positive pressure, then rapidly generating negative pressure to suction, loosening sputum in the peripheral small airways and guiding it to the main airway. Most commercially available expectorants employ a dual-turbine system with complex solenoid valves to achieve alternating positive and negative pressure. The working principle involves one turbine specifically generating positive pressure and another specifically generating negative pressure, switching the airway via a sophisticated solenoid valve network to direct either positive or negative pressure to the patient. However, this system is complex and expensive. The dual-turbine, multi-valve, and complex piping design results in a large overall size, leading to high manufacturing and maintenance costs. Furthermore, it suffers from response delays and significant pressure fluctuations. Airway switching relies on the physical action of mechanical valves, with response times on the order of hundreds of milliseconds. The transition between positive and negative pressure is slow and difficult to be smooth, failing to generate an ideal and precise cough waveform and impacting sputum expectoration efficiency.

[0030] Fiberoptic bronchoscopy suctioning allows for visualized deep bronchial suctioning and is a clinically recognized method for this purpose. However, it is essentially a mechanical removal of sputum from the large airways and cannot effectively loosen sputum in the alveoli and small airways. Furthermore, the equipment is expensive, requires a high level of expertise to operate, involves a complex sterilization process, and can impede airflow during the procedure, affecting the patient's ventilation.

[0031] The existing patent publication number CN219071651U describes a breathing and sputum-clearing integrated machine that provides a physical integration solution for breathing and sputum clearing. However, it uses two independent power sources and a shut-off valve switching mode, which makes the system cumbersome and unable to achieve high-speed seamless pressure switching.

[0032] The existing patent publication number CN112274742A describes a cough device and control method based on a positive and negative pressure electromagnetic regulating valve. It relies on the complex mechanical structure of the positive and negative pressure electromagnetic regulating valve for airway guidance and switching. The response speed and reliability are limited by the physical characteristics of the mechanical valve.

[0033] Based on this, see Figures 1-2 As shown, this embodiment provides a positive and negative pressure airway clearing system based on high-speed switching of a single turbine, including a pressure generation unit, a control unit, and an airway interface unit. The pressure generation unit includes an electric turbine and a sensing component disposed at the airway output end of the electric turbine. The electric turbine is configured to switch between forward and reverse rotation to generate positive and negative airflow respectively. The sensing component is used to detect the pressure and flow parameters at the airway output end. The control unit is electrically connected to the pressure generation unit and includes a processing module and a drive module coupled thereto. The drive module is used to drive the electric turbine. The airway interface unit includes an airway pipe communicating with the patient's airway and a human-machine interface for parameter setting and mode selection. The processing module receives feedback signals from the sensing component and compares the feedback signals with preset target pressure or flow parameters to generate electronic control signals. The control unit is configured to output electronic control signals to the electric turbine through the drive module.

[0034] A high-speed two-position three-way solenoid valve is installed at the air output end of the electric turbine blower. The valve port P of the high-speed two-position three-way solenoid valve is connected to the electric turbine blower, the valve port B of the high-speed two-position three-way solenoid valve is connected to the negative pressure generation circuit, and the valve port A of the high-speed two-position three-way solenoid valve is connected to the air output end.

[0035] In this embodiment, the electric turbine fan is driven by a brushless DC motor and is configured to quickly switch between forward and reverse rotation. By changing the direction of rotation, it achieves the alternation of positive and negative airflow without relying on mechanical valves to switch the air path. The sensing component is used to detect the pressure and flow parameters at the air path output in real time, providing feedback for closed-loop control. By using a single high-performance turbine fan to replace the traditional dual-turbine and complex valve system, the complexity, size, weight and manufacturing cost of the equipment are significantly reduced. The pressure generation unit and the control unit work together to achieve millisecond-level switching of the electric turbine fan's operating state, making the alternation of positive and negative pressure rapid and smooth, thereby generating a pressure waveform that is efficient and close to that of a physiological cough.

[0036] In this embodiment, a brushless DC centrifugal fan is selected as the electric turbine fan. Brushless DC centrifugal fans have advantages such as a wide speed adjustment range, fast response speed, high operating efficiency, and low vibration and noise. Their rotors have no brush wear, have a long service life, and can meet the needs of long-term continuous operation in clinical settings. At the same time, the aerodynamic characteristics of the brushless DC centrifugal fan are adapted to both forward and reverse rotation conditions, and can stably output airflow with preset pressure and flow rate under both directions.

[0037] In this embodiment, the sensing components include a bidirectional differential pressure sensor and a thermal mass flow meter. The bidirectional differential pressure sensor is used to measure the real-time pressure at the gas path output end, and the thermal mass flow meter is used to measure the real-time flow rate at the gas path output end.

[0038] The bidirectional differential pressure sensor uses the Sensirion SDP8xx series MEMS differential pressure sensor, which features high precision, high response speed and small size. It has a range of -100 to +100 cm water column, full-range accuracy better than ±1%, and bandwidth of not less than 100 Hz, which can accurately capture pressure change signals during high-speed switching.

[0039] The thermal mass flow meter uses a flow sensor with a range of 0~200L / min and a response time (T90) of less than 20ms to have excellent dynamic response performance.

[0040] In this embodiment, the processing module is a digital signal processor, and the drive module is connected to the three-phase winding of the electric turbine fan to convert the space vector pulse width modulation signal generated by the processing module into a three-phase AC signal to drive the electric turbine fan.

[0041] The airway interface unit also includes an intake filter, a silencer, and a ventilator tubing interface. The intake filter is located at the intake end of the electric turbine fan; the silencer is located inside the airway; and the ventilator tubing interface is located at the outlet end of the airway, and is used to connect to the patient's endotracheal tube.

[0042] In this embodiment, the human-machine interface includes a touch screen or physical buttons, and the human-machine interface is configured to receive parameter settings from the user for working mode, positive pressure value, negative pressure value, pressure duration and number of cycles.

[0043] Furthermore, this embodiment also provides a positive and negative pressure airway cleaning method based on high-speed switching of a single turbine, employing the aforementioned positive and negative pressure airway cleaning system, see [link to documentation]. Figure 3 As shown, the positive and negative pressure airway clearing method includes the following steps: S1. Set the target pressure parameters or select the working mode through the human-computer interaction interface; S2. The control unit generates corresponding electronic control signals based on the selected mode and parameters; S3, the drive module drives the electric turbine fan to run at the target speed and direction according to the electronic control signal; S4. Real-time monitoring of the pressure and flow rate at the gas output end via sensing components, and feedback to the control unit; S5. The control unit adjusts the electronic control signal in real time based on the deviation between the feedback signal and the target parameter to achieve closed-loop control of the output pressure.

[0044] Specifically, the drive module drives the electric turbine fan to operate at a target speed and direction based on electronic control signals, including the following steps: At the end of the previous pressure period, the control unit applies a reverse voltage vector to the electric turbine fan through the drive module, causing the electric turbine fan to enter a regenerative braking state to decelerate. Monitor the rotational speed of the electric turbine fan. When the rotational speed is lower than a preset threshold, apply a reverse drive voltage vector to accelerate the electric turbine fan in the opposite direction to the target rotational speed.

[0045] When the operating mode is active expectoration mode, the positive and negative pressure airway clearance method includes performing at least one expectoration sequence, each expectoration sequence including: Control the electric turbine fan to rotate forward, inflate the patient's lungs with a first preset positive pressure, and continue for a first preset time, wherein the first preset positive pressure is +35cmH2O and the first preset time is 2~3 seconds, so that the alveoli and distal airways expand and loosen the attached sputum. Within 200 milliseconds, the electric turbine fan is controlled to switch from forward to reverse rotation, drawing air from the patient's airway with a second preset negative pressure and continuing for a second preset time. The second preset negative pressure is -35cmH2O and the second preset time is 3~4 seconds, forming a high-speed exhaled airflow in the airway, pushing the loosened sputum from the periphery to the central airway.

[0046] Taking the active sputum expectoration mode as an example, its working parameters can be configured as shown in Table 1 below.

[0047] Table 1. Operating parameter configuration for active sputum clearance mode

[0048] The positive and negative pressure airway clearing method also includes intelligent collaborative control steps: When the positive and negative pressure airway clearance system is used in conjunction with the mechanical ventilation equipment, the control unit monitors the patient's respiratory phase status in real time. When the patient is determined to have entered the expiratory phase, the processing module adjusts the control target of the electric turbine fan to maintain a constant auxiliary negative pressure to help the patient expel airway secretions. When the expiratory phase is detected to have ended and the patient has entered the inspiratory phase, the processing module will restore the control target to the preset pressure or flow parameters required for mechanical ventilation.

[0049] In this embodiment, the human-machine interface (HMI) is used to enable users to set device parameters and select modes. It can employ a touchscreen or physical buttons to adapt to the operational needs of different clinical scenarios. The HMI is configured to receive user settings for operating mode, positive pressure value, negative pressure value, pressure duration, and number of cycles.

[0050] In this embodiment, medical staff set target pressure parameters or select preset working modes through a human-computer interaction interface. Preset working modes include active sputum clearance mode, assisted sputum clearance mode, and coordinated ventilation mode. Different modes correspond to preset combinations of parameters such as pressure parameters, switching frequency, and duration to suit the needs of patients with different conditions. Alternatively, positive pressure value, negative pressure value, pressure duration, and number of cycles can be manually set according to the individual patient's condition. After setting, the parameter information is transmitted to the processing module of the control unit as a control reference.

[0051] The processing module of the control unit generates corresponding electronic control signals based on the selected working mode and set parameters. The electronic control signals include information such as the direction command, speed command, and running time command of the electric turbine fan, providing a basis for the fan drive.

[0052] The drive module receives the electronic control signal generated by the processing module, converts it into a corresponding three-phase AC signal, and drives the electric turbine fan to run at the target speed and direction, generating positive or negative pressure airflow. The airflow is transmitted to the patient's airway through the airway pipeline to realize airway inflation or secretion aspiration.

[0053] To achieve high-speed steering switching of the electric turbine wind turbine, the drive module adopts a coordinated control strategy of regenerative braking and reverse acceleration. The specific steps include: At the end of the previous pressure period, the control unit applies a reverse voltage vector to the electric turbine fan through the drive module, causing the electric turbine fan to enter a regenerative braking state. It uses the motor's own back electromotive force to achieve rapid deceleration, and the deceleration time can be controlled within 200 milliseconds. At the same time, the processing module monitors the speed signal of the electric turbine fan in real time. When the speed is lower than the preset threshold, the drive module applies a reverse drive voltage vector, causing the electric turbine fan to accelerate in the opposite direction to the target speed, completing the direction switching and speed stabilization. The entire switching process takes no more than 300 milliseconds, ensuring the steepness of the pressure waveform switching and simulating the rapid pressure change process of physiological coughing.

[0054] During the operation of the electric turbine fan, the sensing components continuously monitor the pressure and flow parameters at the output end of the air path in real time. The bidirectional differential pressure sensor and the thermal mass flow meter convert the detected analog signals into digital signals and transmit them to the processing module of the control unit. The transmission rate is not less than 100Hz to ensure the real-time nature of the feedback signal.

[0055] The processing module compares the received pressure and flow feedback signals with the preset target parameters, calculates the parameter deviation, and then dynamically adjusts the parameters of the electronic control signal. The drive module adjusts the drive signal output to the electric turbine fan in real time according to the adjusted control signal, changing the fan speed or direction, so that the pressure and flow parameters at the air output end always match the target parameters, achieving closed-loop precise control.

[0056] When the operating mode is active sputum clearance, the positive and negative pressure airway clearance method includes executing at least one sputum clearance sequence. Each sputum clearance sequence includes a positive pressure inflation phase and a negative pressure suction phase: controlling the electric turbine fan to rotate forward, inflating the patient's lungs with a first preset positive pressure, ranging from +20 cmH2O to +50 cmH2O, for a first preset time, ranging from 1.0 s to 4.0 s, expanding the lung airways and loosening airway secretions through positive pressure airflow; then, within 200 milliseconds, switching the electric turbine fan from forward to reverse rotation, suctioning air from the patient's airway with a second preset negative pressure, ranging from -20 cmH2O to... -50cmH2O, for a second preset time, the second preset time range is 1.0s~1.5s. The loosened secretions are aspirated by negative pressure airflow to achieve the sputum expectoration function; multiple sputum expectoration sequences are executed in a cycle, the number of cycles is determined according to the set parameters, and the rest time between cycles can be set to 1min~2min to avoid frequent switching of positive and negative pressure from irritating the patient's airway.

[0057] When the system operates in conjunction with mechanical ventilation equipment, the method also includes intelligent collaborative control steps: the control unit monitors the patient's respiratory phase status in real time through the airway interface unit, including the start and end times of the inspiratory and expiratory phases; when it is determined that the patient has entered the expiratory phase, the processing module adjusts the control target of the electric turbine fan to maintain a constant auxiliary negative pressure, using negative pressure airflow to assist the patient in expelling airway secretions without interfering with the patient's spontaneous exhalation; when it is detected that the expiratory phase has ended and the patient has entered the inspiratory phase, the processing module immediately restores the control target to the preset pressure or flow parameters required for mechanical ventilation, switches to positive pressure assisted ventilation or maintains stable ventilation pressure, achieving seamless collaboration with mechanical ventilation equipment and ensuring patient ventilation safety.

[0058] Based on the above configuration, this embodiment realizes airway clearance in active sputum expectoration mode. The specific working process is as follows: Parameter settings: Medical staff select the active sputum expectoration mode via the touch screen, set the first preset positive pressure to +35cmH2O, set the first preset time to 2~3 seconds, set the second preset positive pressure to -35cmH2O, set the second preset time to 3~4 seconds, and the number of cycles to 5. After the parameter settings are completed, they are submitted to the control unit.

[0059] Control Start-up: The processing module receives parameter information, generates an initial electronic control signal, and the drive module converts the electronic control signal into a three-phase AC signal to drive the brushless DC centrifugal fan to rotate in the forward direction.

[0060] Positive pressure inflation stage: After being filtered by the intake filter and reduced by the silencer, the positive pressure airflow is transmitted to the patient's endotracheal tube through the airway and ventilator tubing interface, enters the patient's airway, and realizes lung inflation and expansion. At the same time, the sensing components monitor the pressure and flow in real time and feed the data back to the processing module. The processing module compares the feedback value with the target value and dynamically adjusts the fan speed.

[0061] Positive and negative pressure switching: After the positive pressure inflation stage ends, the processing module immediately generates a braking control signal. The drive module applies a reverse voltage vector to the fan, and the fan enters the regenerative braking state. The speed drops rapidly. The processing module monitors the speed in real time through the Hall sensor built into the motor. When the speed is lower than the preset threshold, the drive module applies a reverse drive voltage vector, and the fan accelerates in the reverse direction.

[0062] Negative pressure suction stage: The fan runs in reverse to output negative pressure airflow, which is used to suction loose secretions in the patient's airway through the airway pipeline. The sensing components continuously provide feedback on pressure and flow data, and the processing module maintains the negative pressure stable within the predetermined range through closed-loop control.

[0063] Cyclic execution and termination: After one sputum clearance sequence is completed, the system will cycle through the above positive pressure inflation and negative pressure suction process according to the set parameters, for a total of 5 cycles; after the cycle ends, the blower will stop running, the touch screen will display that the sputum clearance is complete, and the data of this operation will be stored.

[0064] If the patient is using mechanical ventilation at the same time, the system will activate the intelligent collaborative control function. The processing module will monitor the patient's respiratory phase status in real time. When the patient enters the expiratory phase, the fan control target will be adjusted to assist negative pressure to help expel secretions. When the inspiratory phase begins, the system will switch to the preset positive pressure for mechanical ventilation to ensure ventilation continuity and achieve coordinated sputum expectoration and ventilation.

[0065] In summary, the positive and negative pressure airway clearing system based on high-speed switching of a single turbine proposed in this invention includes a pressure generation unit, a control unit, and an airway interface unit. The pressure generation unit includes an electric turbine and a sensing component disposed at the airway output end of the electric turbine. The electric turbine is configured to switch between forward and reverse rotation to generate positive and negative airflow respectively. The sensing component is used to detect the pressure and flow parameters at the airway output end. The control unit is electrically connected to the pressure generation unit and includes a processing module and a drive module coupled thereto. The drive module is used to drive the electric turbine. The airway interface unit includes an airway pipe communicating with the patient's airway and a human-machine interface for parameter setting and mode selection. The processing module receives feedback signals from the sensing component and compares the feedback signals with preset target pressure or flow parameters to generate electronic control signals. The control unit is configured to output electronic control signals to the electric turbine through the drive module. This design allows for the replacement of traditional dual-turbine and complex valve systems with a single high-performance turbine fan, significantly reducing the complexity, size, weight, and manufacturing cost of the equipment. The pressure generation unit and control unit work together to achieve millisecond-level switching of the electric turbine fan's operating state, enabling rapid and smooth alternation of positive and negative pressure, thereby generating a highly efficient pressure waveform that closely resembles a physiological cough.

[0066] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A positive and negative pressure airway cleaning system based on high-speed switching of a single turbine, characterized in that, include: A pressure generating unit includes an electric turbine and a sensing component disposed at the air output end of the electric turbine. The electric turbine is configured to switch between forward and reverse rotation to generate positive and negative airflow respectively. The sensing component is used to detect the pressure and flow parameters at the output end of the gas path; The control unit is electrically connected to the pressure generating unit. The control unit includes a processing module and a drive module coupled thereto. The drive module is used to drive the electric turbine fan to operate. The airway interface unit includes an airway tube connected to the patient's airway and a human-computer interaction interface for parameter setting and mode selection. The processing module receives feedback signals from the sensing components and compares the feedback signals with preset target pressure or flow parameters to generate electronic control signals. The control unit is configured to output the electronic control signals to the electric turbine fan through the drive module.

2. The positive and negative pressure airway cleaning system based on high-speed switching of a single turbine according to claim 1, characterized in that, The electric turbine fan is a brushless DC centrifugal fan.

3. The positive and negative pressure airway cleaning system based on high-speed switching of a single turbine according to claim 2, characterized in that, The sensing component includes: A bidirectional differential pressure sensor is used to measure the real-time pressure at the output end of the gas path; A thermal mass flow meter is used to measure the real-time flow rate at the output end of the gas path.

4. The positive and negative pressure airway cleaning system based on high-speed switching of a single turbine according to claim 3, characterized in that, The processing module is a digital signal processor, and the drive module is connected to the three-phase winding of the electric turbine fan, used to convert the space vector pulse width modulation signal generated by the processing module into a three-phase AC signal to drive the electric turbine fan.

5. The positive and negative pressure airway cleaning system based on high-speed switching of a single turbine according to claim 4, characterized in that, The gas interface unit also includes: An air intake filter is disposed at the air intake end of the electric turbine fan; A silencer, wherein the silencer is disposed inside the air passage pipe; A ventilator tubing interface is located at the outlet end of the airway tubing and is used to connect to the patient's endotracheal tube.

6. The positive and negative pressure airway cleaning system based on high-speed switching of a single turbine according to claim 5, characterized in that, The human-machine interface includes a touch screen or physical buttons, and is configured to receive user settings for parameters such as working mode, positive pressure value, negative pressure value, pressure duration, and number of cycles.

7. A method for cleaning positive and negative pressure air passages based on high-speed switching of a single turbine, characterized in that, The positive and negative pressure airway cleaning system according to any one of claims 1 to 6, the positive and negative pressure airway cleaning method includes the following steps: The target pressure parameters or working mode can be set through the human-computer interaction interface; The control unit generates corresponding electronic control signals based on the selected mode and parameters; The drive module drives the electric turbine fan to run at the target speed and direction according to the electronic control signal; The sensing component monitors the pressure and flow rate at the gas output end in real time and feeds them back to the control unit. The control unit adjusts the electronic control signal in real time based on the deviation between the feedback signal and the target parameter, so as to achieve closed-loop control of the output pressure.

8. The method for cleaning positive and negative pressure air passages based on high-speed switching of a single turbine according to claim 7, characterized in that, The drive module drives the electric turbine fan to operate at a target speed and direction according to the electronic control signal, including the following steps: At the end of the previous pressure period, the control unit applies a reverse voltage vector to the electric turbine fan through the drive module, causing the electric turbine fan to enter a regenerative braking state to decelerate. The rotational speed of the electric turbine is monitored. When the rotational speed is lower than a preset threshold, a reverse drive voltage vector is applied to accelerate the electric turbine in the opposite direction to the target rotational speed.

9. The method for cleaning positive and negative pressure air passages based on high-speed switching of a single turbine according to claim 8, characterized in that, When the operating mode is active expectoration mode, the positive and negative pressure airway clearance method includes executing at least one expectoration sequence, each expectoration sequence including: The electric turbine fan is controlled to rotate forward to inflate the patient's lungs with a first preset positive pressure for a first preset time. Within 200 milliseconds, the electric turbine fan is controlled to switch from forward rotation to reverse rotation, drawing air from the patient's airway with a second preset negative pressure, and continuing for a second preset time.

10. The method for cleaning positive and negative pressure air passages based on high-speed switching of a single turbine according to claim 9, characterized in that, The positive and negative pressure airway clearing method also includes an intelligent collaborative control step: When the positive and negative pressure airway clearing system is used in conjunction with the mechanical ventilation equipment, the control unit monitors the patient's respiratory phase status in real time. When the patient is determined to have entered the expiratory phase, the processing module adjusts the control target of the electric turbine fan to maintain a constant auxiliary negative pressure to help the patient expel airway secretions. When the expiratory phase is detected to have ended and the patient has entered the inspiratory phase, the processing module will restore the control target to the preset pressure or flow parameters required for mechanical ventilation.

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