A Nebulizer Flow Adaptive Control Method and System Based on Respiratory Rate Detection

Abstract

This invention discloses an adaptive control method and system for nebulized flow rate based on respiratory rate detection, relating to the field of medical device nebulization control technology. The method includes: acquiring and filtering upstream and downstream pressure sequences of the nebulization path; calculating a differential pressure short-circuit index and generating an event flag based on the degree of synchronization fluctuation and differential pressure amplitude of the two sequences; determining a respiratory rate estimation signal and calculating the respiratory rate based on the flag; generating a baseline nebulized flow rate based on the respiratory rate and correcting it with the differential pressure short-circuit index to obtain the target nebulized flow rate; and finally determining the nebulization execution amount. This invention enables adaptive and conservative adjustment of the nebulized flow rate, improving delivery stability.

Description

Technical Field

[0001] This invention relates to the field of medical device nebulization control technology, and in particular to an adaptive control method and system for nebulization flow rate based on respiratory rate detection. Background Technology

[0002] Nebulized delivery devices often need to operate in a way that adapts to the user's breathing rhythm to increase effective inhalation volume and reduce waste. Traditional devices often output at a fixed rate or only have simple triggering functions, and cannot dynamically adjust to changes in breathing speed. This can easily lead to problems such as unstable inhalation or media leakage. In order to achieve adaptive flow control, existing technologies usually use the differential pressure measurement principle. That is, pressure taps are set at both ends of the airway resistance element. By collecting the upstream and downstream pressures and calculating the difference between the two, a differential pressure signal reflecting the respiratory flow is obtained. Then, the breathing frequency is calculated based on this signal, and the output of the nebulization actuator is adjusted.

[0003] However, during nebulization, the gas path is in a two-phase flow environment where high-humidity gas and droplets coexist. Liquid film accumulation and droplet coalescence are easily generated near the pressure tap. When the liquid accumulation reaches a certain critical condition, capillary bridging occurs, causing an unexpected physical connection between the upstream and downstream pressure tapping areas. This connection leads to a threshold-like collapse or plateauing of the differential pressure signal amplitude, making it impossible for the differential pressure signal to accurately reflect the actual respiratory airflow fluctuations. Existing signal processing methods are unable to accurately identify this state when the differential pressure fails, resulting in a serious deviation in the calculation of the respiratory rate. The misjudgment of the respiratory rate directly misleads the flow control logic, causing the target nebulization flow rate to deviate from the actual requirement, ultimately leading to a significant decrease in the stability of nebulization delivery. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies where, under conditions of high humidity two-phase flow in atomization, capillary bridging of the pressure tapping structure easily leads to distortion of the differential pressure signal, which in turn causes misjudgment of the breathing frequency, resulting in inaccurate adaptive adjustment of the atomization flow rate and unstable effective delivery. Therefore, this invention proposes an adaptive control method and system for atomization flow rate based on breathing frequency detection.

[0005] To address the problems existing in the prior art, the present invention adopts the following technical solution: The nebulizer flow rate adaptive control method based on respiratory rate detection includes: S1. Collect the upstream and downstream pressure sequences in the atomizing gas path, and filter the collected sequences. S2. Based on the degree of synchronous fluctuation between the upstream and downstream pressure tapping sequences and the differential pressure amplitude, calculate the differential pressure short-circuit index and generate a differential pressure short-circuit event flag based on the differential pressure short-circuit index. S3. Determine the respiratory rate estimation signal based on the differential pressure short-circuit event flag, and calculate the respiratory rate based on the respiratory rate estimation signal; S4. Generate a basic nebulization flow rate based on the breathing rate, and correct the basic nebulization flow rate using the differential pressure short-circuit index to obtain the target nebulization flow rate; S5. Determine the atomization execution amount based on the target atomization flow rate.

[0006] Preferably, the acquired sequence is filtered, including: The difference between the upstream and downstream pressure tapping sequences is calculated to obtain the differential pressure sequence. The upstream pressure sampling sequence, downstream pressure sampling sequence, and differential pressure sequence are bandpass filtered within a preset sliding window to obtain the upstream filtered pressure, downstream filtered pressure, and filtered differential pressure, respectively.

[0007] Preferably, calculating the differential pressure short-circuit index includes: Calculate the correlation coefficient between upstream filter pressure and downstream filter pressure; The statistical distribution width of the filtered differential pressure within the sliding window is used as the differential pressure amplitude. The absolute pressure amplitude is obtained by calculating the average of the statistical distribution width of the upstream filter pressure within the sliding window and the statistical distribution width of the downstream filter pressure within the sliding window. Calculate the ratio of the differential pressure amplitude to the absolute pressure amplitude, calculate the difference obtained by subtracting the ratio from the calculated value, and obtain the intermediate value by multiplying the difference by the correlation coefficient. By restricting the intermediate value to a range of zero to one, the differential pressure short-circuit index is obtained.

[0008] Preferably, generating a differential pressure short-circuit event flag based on the differential pressure short-circuit index includes: If the differential pressure short circuit index is greater than or equal to the preset short circuit judgment threshold, the differential pressure short circuit event flag is set to the valid state; otherwise, the differential pressure short circuit event flag is set to the invalid state.

[0009] Preferably, determining the respiratory rate estimation signal based on the differential pressure short-circuit event flag includes: When the differential pressure short-circuit event flag is in an active state, it is determined that the differential pressure signal is distorted, and the upstream filter pressure is selected as the respiratory rate estimation signal. When the differential pressure short-circuit event flag is invalid, the differential pressure signal is determined to be normal, and the filtered differential pressure is selected as the respiratory rate estimation signal.

[0010] Preferably, calculating the respiratory rate based on the respiratory rate estimation signal includes: Power spectral density analysis was performed on the respiratory rate estimation signal to obtain the power spectrum; The main peak frequency of the power spectrum is searched within the preset breathing frequency band boundary, and the main peak frequency is converted into the number of breaths per unit of time to obtain the breathing frequency.

[0011] Preferably, generating a basic nebulization flow rate based on the breathing rate includes: Obtain the minimum and maximum nebulization flow rates, reference nebulization flow rates, and reference respiratory rate; The formula for calculating the basic atomization flow rate is: In the formula, Based on the atomization flow rate, To minimize the atomization flow rate, For maximum atomization flow rate, For reference respiratory rate, Respiratory rate, For reference atomization flow rate.

[0012] Preferably, the basic atomization flow rate is corrected by the differential pressure short-circuit index, including: The attenuation ratio is obtained by multiplying the differential pressure short-circuit index by the preset short-circuit risk conservative coefficient. Subtract the attenuation ratio from the calculated value to obtain the retention ratio; The target atomization flow rate is obtained by multiplying the base atomization flow rate by the retention ratio.

[0013] Preferably, determining the atomization execution amount based on the target atomization flow rate includes: Based on the linear calibration relationship between the flow rate and execution volume of the atomizing actuator, the target atomizing flow rate is converted into the corresponding atomizing execution volume; The atomization execution parameters include at least one of pump speed, fan frequency, or valve opening.

[0014] To address the above problems, the present invention also provides an adaptive control system for nebulization flow rate based on respiratory rate detection, the system comprising: The signal acquisition and processing module is used to acquire the upstream and downstream pressure sequences in the atomizing gas path and to filter the acquired sequences. The short-circuit identification module is used to calculate the differential pressure short-circuit index based on the degree of synchronization fluctuation between the upstream and downstream pressure tapping sequences and the differential pressure amplitude, and to generate a differential pressure short-circuit event flag based on the differential pressure short-circuit index. The respiratory rate module is used to determine the respiratory rate estimation signal based on the differential pressure short-circuit event flag, and to calculate the respiratory rate based on the respiratory rate estimation signal; The target flow module is used to generate a basic nebulization flow rate based on the breathing rate, and to correct the basic nebulization flow rate by using the differential pressure short-circuit index to obtain the target nebulization flow rate. The execution control module is used to determine the atomization execution amount based on the target atomization flow rate.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention constructs a differential pressure short-circuit index by calculating the synchronous fluctuation degree of upstream and downstream pressure taps and the ratio of differential pressure amplitude to absolute pressure amplitude to quantitatively characterize the capillary bridging state of pressure taps in atomized high-humidity two-phase flow environments. The event flag generated by this index can drive the adaptive switching of the respiratory rate estimation signal. That is, when the differential pressure signal is found to be distorted by threshold collapse due to liquid film coalescence, the upstream filtered pressure is automatically selected to replace the differential pressure sequence for spectral analysis. This signal self-selection mechanism effectively avoids the interference of differential pressure signal failure caused by the connection of the pressure tap structure, ensuring that the respiratory rhythm can still be accurately tracked by utilizing the periodic characteristics of upstream pressure fluctuations under complex high-humidity conditions, significantly improving the anti-interference ability and robustness of respiratory rate detection.

[0016] 2. This invention establishes a basic nebulization flow generation logic that is negatively correlated with respiratory rate, and directly introduces the differential pressure short-circuit index into the target flow correction stage, realizing conservative response control for short-circuit risk. By calculating the product of the differential pressure short-circuit index and the preset conservative coefficient, the retention ratio is dynamically adjusted, so that when the short-circuit risk of the pressure tap is detected to increase, the target nebulization flow can be automatically and smoothly reduced. This not only realizes the adaptive adjustment of nebulization output with breathing rate to match ventilation demand, but also effectively prevents control divergence or over-spraying caused by abnormal sensor physical state. Thus, while ensuring effective inhalation volume, it reduces media leakage loss and user discomfort, and greatly improves the safety and delivery stability of the nebulization process. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a flowchart illustrating the adaptive control method for nebulized flow rate based on respiratory rate detection of the present invention. Figure 2 This is a functional block diagram of the nebulization flow adaptive control system based on respiratory rate detection of the present invention. Figure 3 This is a schematic diagram of the differential pressure short-circuit principle of the present invention; Figure labels: 1 is the upstream pressure tap, 2 is the downstream pressure tap, 3 is the resistance element, 4 is the capillary bridging liquid film, 5 is the airflow direction, and 6 is the droplet. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] Example: This example provides an adaptive control method for nebulized flow rate based on respiratory rate detection. See [link to example]. Figure 1 Specifically, including: S1. Collect the upstream and downstream pressure sequences in the atomizing gas path, and filter the collected sequences. In an embodiment of the present invention, filtering processing of the acquired sequence includes: Collect the upstream and downstream pressure sequences in the atomizing gas path; The difference between the upstream and downstream pressure tapping sequences is calculated to obtain the differential pressure sequence. The upstream pressure tapping sequence, downstream pressure tapping sequence, and differential pressure sequence are bandpass filtered within a preset sliding window to obtain the upstream filtered pressure, downstream filtered pressure, and filtered differential pressure, respectively. Specifically, the nebulizing air path refers to the flow path formed by the guide channel and local resistance components through which the gas and drug droplets output by the nebulizer pass. The upstream pressure sampling sequence is a set of pressure change data over time obtained by continuously sampling from the upstream pressure taps located at the local resistance components or equivalent pressure tap positions. It reflects the static pressure level before the airflow enters this section of the air path and the periodic pressure fluctuations caused by the alternation of inhalation and exhalation. The downstream pressure sampling sequence is a set of pressure change data over time obtained by continuously sampling from the downstream pressure taps located at the downstream side of the local resistance components. It reflects the static pressure level after the airflow passes through this section of the air path and the pressure fluctuations caused by breathing. The differential pressure sequence is a time series obtained by subtracting the upstream and downstream pressure sampling sequences point by point at the same sampling time. It characterizes the effect of this section of the air path on the airflow. The pressure drop is correlated with the instantaneous flow strength through that section of the airway. Bandpass filtering is a signal processing procedure that retains only the frequency components related to respiration within the pressure sequence and suppresses low-frequency drift and high-frequency disturbances within a sliding window. Low-frequency drift usually comes from slow baseline changes and gradually varying pressure drops in the airway, while high-frequency disturbances usually come from turbulent pulsations, mechanical vibrations, and transient jet noise. The upstream and downstream filtered pressures are the pressure change data over time obtained after bandpass filtering the upstream and downstream pressure sequences, respectively. They mainly show the periodic fluctuations driven by respiration while weakening the gradually varying components and sharp noises unrelated to respiration. The filtered differential pressure is the pressure drop data over time obtained after bandpass filtering the differential pressure sequence. It mainly reflects the alternating changes in pressure drop within the respiratory cycle and can be used for subsequent calculations of respiratory rhythm estimation and nebulization control-related quantities.

[0020] In detail, when the nebulizer is running and the nebulizing air path is connected, the controller synchronously reads the pressure sensor outputs of the upstream and downstream pressure taps located on both sides of the resistance component of the nebulizing air path at a constant sampling period. The upstream pressure taps obtained by continuous sampling are arranged into an upstream pressure tap sequence in time order, and the downstream pressure taps obtained by continuous sampling are arranged into a downstream pressure tap sequence in time order. The sampling frequency is preferably between 50 Hz and 200 Hz to ensure sufficient time resolution for breathing fluctuations of 6 to 60 times per minute without excessively increasing the computational burden. Before sampling, the pressure sensors are zero-point calibrated, and a timestamp is recorded at each sampling time to ensure that the two pressures are aligned at the same sampling time. Then, at each sampling time alignment point, the difference between the upstream and downstream pressure taps is calculated and written into the differential pressure sequence in time order to characterize the pressure drop change of the nebulizing air path at that time.

[0021] To suppress non-respiratory components such as slow baseline drift and mechanical vibration, and to extract respiratory-related fluctuations, a preset sliding window is set, and the three sequences mentioned above are subjected to in-window bandpass filtering. The sliding window duration is preferably five to fifteen seconds to cover at least three complete respiratory cycles, thereby stabilizing the frequency domain filtering and subsequent frequency estimation. The window step size is preferably 0.2 to 1 second to balance real-time updates and numerical smoothing. The lower passband frequency of the bandpass filter is preferably 0.1 Hz to filter out low-frequency drift caused by gradual pressure drop in the airway and sensor zero drift. The upper passband frequency is preferably 1 Hz to 1.5 Hz to cover rapid breathing and suppress turbulent pulsations and pump vibration. For the high-frequency noise introduced, the preferred filter type is a fourth-order Butterworth digital bandpass filter to obtain a flat passband and reduce the amplitude distortion of the respiratory waveform. When implementing the filter, bidirectional filtering or equivalent zero-phase processing is used to reduce the impact of phase shift on peak and valley localization. Bandpass filtering is performed on the upstream pressure sequence within each sliding window to obtain the upstream filtered pressure, and bandpass filtering is performed on the downstream pressure sequence to obtain the downstream filtered pressure. Bandpass filtering is performed on the differential pressure sequence to obtain the filtered differential pressure. Finally, the upstream filtered pressure, downstream filtered pressure and filtered differential pressure are used as the outputs corresponding to the sliding window for subsequent differential pressure short-circuit index calculation and respiratory rate estimation.

[0022] S2. Based on the degree of synchronous fluctuation between the upstream and downstream pressure tapping sequences and the differential pressure amplitude, calculate the differential pressure short-circuit index and generate a differential pressure short-circuit event flag based on the differential pressure short-circuit index. In an embodiment of the present invention, calculating the differential pressure short-circuit index and generating a differential pressure short-circuit event flag based on the differential pressure short-circuit index includes: Calculate the correlation coefficient between upstream filter pressure and downstream filter pressure; The statistical distribution width of the filtered differential pressure within the sliding window is used as the differential pressure amplitude. Specifically, the correlation coefficient is a statistic used to characterize whether the upstream and downstream filter pressures fluctuate synchronously within the same sliding window. Its value is determined by the degree of unidirectional change in the two pressure fluctuations. When the two pressures rise and fall simultaneously under breathing drive and their waveforms closely match, the correlation coefficient approaches one. When the fluctuations of the two pressures are asynchronous or their directions of change are inconsistent, the correlation coefficient decreases or even becomes negative. Therefore, the correlation coefficient can reflect whether there is a convergence phenomenon in the pressure taking domain and provide a quantitative basis for identifying differential pressure short-circuit states. The differential pressure amplitude is an index used to characterize the strength of the fluctuation of the filter differential pressure within the sliding window. It describes the typical fluctuation range by statistically analyzing the distribution width of the filter differential pressure within the sliding window. The larger the differential pressure amplitude, the more obvious the pressure drop in that section of the nebulized gas path changes with breathing. The smaller the differential pressure amplitude, the more abnormally compressed the fluctuation of the filter differential pressure is, and the more plateau-like it becomes. This can be used to determine whether the differential pressure has experienced threshold collapse. Threshold-type collapse refers to the phenomenon where the differential pressure-related signal does not decrease slowly and continuously during the operation of the nebulized gas path. Instead, within a short time window, when the humidification state and geometric connectivity conditions reach a certain critical level, the typical fluctuation amplitude of the signal suddenly decreases and remains at a significantly low level within that sliding window. This phenomenon manifests as the filtered differential pressure changing from a clear periodic fluctuation with respiration to a sudden decrease in fluctuation amplitude or a plateau. This results in a significant drop in differential pressure amplitude between adjacent sliding windows, forming an approximately switch-like state switching characteristic. Its formation mechanism is usually related to the local connectivity generated after the liquid film near the pressure tapping hole coalesces, which partially cancels out or effectively short-circuits the pressure drop fluctuation originally caused by the gas path resistance, thus making the differential pressure fluctuation statistically exhibit a sudden compression after a critical trigger.

[0023] In detail, within each preset sliding window, the upstream and downstream filter pressures corresponding to that window are read. First, the two sequences undergo deDC processing to eliminate the interference of baseline differences within the window on the synchronous fluctuation discrimination. This deDC processing involves calculating the arithmetic mean of the upstream and downstream filter pressures within the sliding window, and then subtracting their respective arithmetic mean points from each sequence to obtain the upstream and downstream fluctuation sequences with zero mean. Subsequently, the correlation coefficient is calculated within the sliding window. The formula for calculating the correlation coefficient is: In the formula, This is the correlation coefficient between upstream and downstream filter pressures, used to characterize the degree of synchronous fluctuation between the two within the sliding window. Let be the upstream filter pressure sampled value at the i-th sampling time within the sliding window. This represents the arithmetic mean of the upstream filter pressure within the sliding window. Let be the downstream filter pressure sampled value at the i-th sampling time within the sliding window. This represents the arithmetic mean of the downstream filter pressure within the sliding window. The number of sampling points within the sliding window is used because it is insensitive to the pressure dimension and can reflect the phase consistency and co-directional change of the two pressure fluctuations in a normalized form, thus characterizing the phenomenon of enhanced synchronous fluctuation caused by the convergence of pressure domains due to capillary bridging.

[0024] After completing the correlation coefficient calculation, the filtered differential pressure sequence is read within the same sliding window and its statistical distribution width is calculated as the differential pressure amplitude. The statistical distribution width preferably adopts the quantile difference to suppress the peak effect caused by cough or instantaneous disturbance. Specifically, after sorting all the sampled values ​​of the filtered differential pressure within the sliding window, the 95th percentile value and the 5th percentile value are taken and the difference between the two is calculated. This difference is used as the differential pressure amplitude. The basis for this is that the difference can reflect the typical amplitude range of differential pressure fluctuation within the sliding window and is not sensitive to a small number of outliers, thus more stably characterizing whether the differential pressure has a threshold collapse.

[0025] The absolute pressure amplitude is obtained by calculating the average of the statistical distribution width of the upstream filter pressure within the sliding window and the statistical distribution width of the downstream filter pressure within the sliding window. Calculate the ratio of the differential pressure amplitude to the absolute pressure amplitude, calculate the difference obtained by subtracting the ratio from the calculated value, and obtain the intermediate value by multiplying the difference by the correlation coefficient. By restricting the intermediate value to a range of zero to one, the differential pressure short-circuit index is obtained. It should be noted that the differential pressure short-circuit index is an indicator used to quantify whether a differential pressure short-circuit threshold event has occurred in the pressure tapping structure of the nebulizer gas path. It characterizes the degree of short-circuit risk by simultaneously depicting two types of phenomena. One type of phenomenon is whether the upstream and downstream filter pressures exhibit stronger synchronous fluctuations within the same sliding window. The other type of phenomenon is whether the typical fluctuation amplitude of the filter differential pressure within the same sliding window is significantly compressed relative to the typical fluctuation amplitude of the absolute pressures at both ends. The closer the differential pressure short-circuit index is to one, the more synchronous the upstream and downstream pressures are and the closer the differential pressure fluctuation is to a plateau. This is more consistent with the state where the pressure tapping domain tends to converge after the liquid film near the pressure tapping hole coalesces and forms a local connection. The closer the differential pressure short-circuit index is to zero, the less prominent the synchronicity of the upstream and downstream pressures is and the differential pressure still fluctuates normally with breathing. This indicates that the pressure tapping domain has not experienced a connection state that would cause abnormal collapse of the differential pressure. Therefore, the differential pressure short-circuit index can serve as a core criterion for identifying differential pressure short-circuit events and for state switching and conservative adjustment of respiratory rate detection and adaptive control of nebulizer flow.

[0026] In detail, within each preset sliding window, the statistical distribution widths of the upstream and downstream filter pressures within the same sliding window are calculated to characterize the typical fluctuation amplitudes of the two absolute pressures. The statistical distribution width preferably uses the quantile difference to reduce the impact of cough spikes or instantaneous jet disturbances on amplitude estimation. Specifically, after sorting all sampled values ​​of the upstream filter pressure within the sliding window, the 95th percentile and the 5th percentile are taken, and the difference between the two is calculated to obtain the upstream statistical distribution width. The downstream filter pressure within the sliding window is obtained in the same way. Then, the arithmetic mean of the upstream and downstream statistical distribution widths is calculated to obtain the absolute pressure amplitude. The basis for this is that during the process of capillary bridging leading to convergence of pressure domains, the upstream and downstream absolute pressures often retain synchronous fluctuations with respiration. Therefore, using the average amplitude of the pressure fluctuations at both ends as a reference can reflect the common fluctuation energy still existing within the same window and provide a normalized benchmark for the degree of differential pressure collapse.

[0027] After obtaining the absolute pressure amplitude, the calculated differential pressure amplitude within the sliding window is read, and the ratio of the differential pressure amplitude to the absolute pressure amplitude is calculated. To avoid the denominator approaching zero and causing numerical instability when the absolute pressure amplitude fluctuates very weakly, a very small positive number is preferably added to the denominator, preferably on the order of 1 x 10^-6 to 1 x 10^-3, to achieve zero-prevention protection without changing the amplitude scale. Then, the difference is obtained by subtracting the ratio from the value. This difference increases as the differential pressure collapses and decreases as the differential pressure recovers, thus mapping the degree of differential pressure collapse relative to absolute pressure to a positive enhancement. This difference is then compared with the values ​​obtained within the same sliding window. The correlation coefficients are multiplied to obtain the median value. The correlation coefficient is used to characterize whether the upstream and downstream pressures exhibit synchronous fluctuations, while the difference is used to characterize whether the differential pressure collapses relative to the reference amplitude. Multiplying the two ensures that the median value increases significantly only when synchronous fluctuations increase and differential pressure collapse occurs simultaneously, thus better reflecting the physical characteristics of differential pressure short-circuit threshold events. Finally, to standardize the median value to a uniform dimension and facilitate subsequent comparison with the short-circuit judgment threshold, the median value is restricted to a numerical range of zero to one to obtain the differential pressure short-circuit index. The restriction operation is to take zero when the median value is less than zero, take one when the median value is greater than one, and otherwise take the median value, thus obtaining a differential pressure short-circuit index that can be stably compared under different individuals and different operating conditions.

[0028] If the differential pressure short circuit index is greater than or equal to the preset short circuit judgment threshold, the differential pressure short circuit event flag is set to the valid state; otherwise, the differential pressure short circuit event flag is set to the invalid state. In detail, after each sliding window calculation, the differential pressure short-circuit index corresponding to that sliding window is read and compared with a preset short-circuit judgment threshold to generate a differential pressure short-circuit event flag. The short-circuit judgment threshold is preferably set to 0.6 to 0.85 to balance the sensitivity to differential pressure threshold collapse and the ability to resist false judgments of general noise fluctuations. Furthermore, the short-circuit judgment threshold is determined through the equipment calibration process. During equipment factory calibration or maintenance recalibration, multiple sets of upstream filter pressure sequences, downstream filter pressure sequences, and filter differential pressure sequences under normal gas path conditions are collected. Multiple sets of corresponding data are also collected under conditions where liquid film aggregation occurs near the pressure tap and differential pressure fluctuations show significant compression. Based on each set of data, the differential pressure short-circuit index is calculated to obtain the normal state index distribution range and the short-circuit state index distribution range. The boundary position of the two states or the position that minimizes the combined false judgment rate and false negative rate is determined as the short-circuit judgment threshold. When the device is used with nebulizer attachments of different age groups or different resistance levels, corresponding threshold parameter tables can be established. The controller can then call the corresponding short-circuit judgment threshold based on the current attachment type, airway resistance level, or usage mode, thereby ensuring that the differential pressure short-circuit event flag has stable consistency and repeatability under different operating conditions. The comparison rule is as follows: when the differential pressure short-circuit index is greater than or equal to the short-circuit judgment threshold, it is determined that there is a combination of increased synchronous fluctuations in upstream and downstream pressures and relative collapse of differential pressure fluctuations within the sliding window. In this case, the differential pressure short-circuit event flag is set to an effective state to indicate that the current state is in a differential pressure short-circuit risk state. When the differential pressure short-circuit index is less than the short-circuit judgment threshold, it is determined that the differential pressure within the sliding window still maintains normal fluctuations consistent with the airway pressure drop, or that the synchronicity of upstream and downstream pressures is insufficient to support a short-circuit judgment. In this case, the differential pressure short-circuit event flag is set to an invalid state to indicate that the current state is not in a differential pressure short-circuit risk state. This differential pressure short-circuit event flag is then used in conjunction with the subsequent selection of the breathing rate estimation signal for the sliding window and the adaptive adjustment process of the nebulizer flow rate.

[0029] S3. Determine the respiratory rate estimation signal based on the differential pressure short-circuit event flag, and calculate the respiratory rate based on the respiratory rate estimation signal; In an embodiment of the present invention, determining a respiratory rate estimation signal based on a differential pressure short-circuit event flag and calculating the respiratory rate based on the respiratory rate estimation signal includes: When the differential pressure short-circuit event flag is in an active state, it is determined that the differential pressure signal is distorted, and the upstream filter pressure is selected as the respiratory rate estimation signal. When the differential pressure short circuit event flag is in an invalid state, the differential pressure signal is determined to be normal, and the filtered differential pressure is selected as the respiratory rate estimation signal. Power spectral density analysis was performed on the respiratory rate estimation signal to obtain the power spectrum; Search for the main peak frequency of the power spectrum within the preset breathing frequency band boundary, and convert the main peak frequency into the number of breaths per unit of time to obtain the breathing frequency; Specifically, respiratory rate is a physiological parameter used to characterize the number of respiratory cycles a subject or patient completes per unit time. It reflects the rhythmic speed of the alternation between inhalation and exhalation and is related to the body's ventilation needs and respiratory drive intensity. In this invention, respiratory rate is calculated from the periodic changes in pressure fluctuations in the nebulized airway. When inhalation begins, the pressure in the airway fluctuates in the same direction as the gas is inhaled, and fluctuates in the opposite direction during the exhalation phase, thus forming an approximately periodic fluctuation sequence. Within a preset respiratory frequency band, the dominant frequency of this periodic fluctuation is identified and converted into the number of breaths per minute as the respiratory rate. The larger the respiratory rate value, the faster the respiratory rhythm, and the smaller the value, the slower the respiratory rhythm. The respiratory rate is used as the input for adaptive control of nebulized flow rate to adjust the nebulization output according to the respiratory rhythm to improve the stability of effective inhalation.

[0030] In detail, each time the sliding window is updated, the differential pressure short-circuit event flag corresponding to that sliding window is read, and the respiratory rate estimation signal is automatically selected accordingly. When the differential pressure short-circuit event flag is valid, it is determined that the filtered differential pressure has experienced threshold collapse, causing the differential pressure signal to no longer reliably reflect the pressure drop fluctuations driven by breathing. Therefore, the upstream filtered pressure is selected as the respiratory rate estimation signal to utilize the periodic pressure fluctuations generated with breathing that it still retains. When the differential pressure short-circuit event flag is invalid, it is determined that there is no short-circuit risk in the differential pressure channel, and the filtered differential pressure is selected as the respiratory rate estimation signal to directly utilize the dominant component of the airway pressure drop that changes with the alternation of inhalation and exhalation.

[0031] After signal selection, power spectral density analysis is performed on the respiratory rate estimation signal within a sliding window to obtain the power spectrum. The power spectral density analysis is preferably implemented using Fast Fourier Transform (FFT), and the signal within the sliding window is first processed by mean reduction and weighted by a window function to reduce spectral leakage. The window function is preferably a Hanning window to reduce sidelobe interference while maintaining frequency resolution. Then, the amplitude of the transformation result is squared and normalized according to the sampling frequency and window length to obtain the power spectrum. Next, the main peak frequency of the power spectrum is searched within the preset respiratory frequency band boundary. The respiratory frequency band boundary is preferably set to 0.1 Hz to 1 Hz to cover the common respiratory range of 6 to 60 breaths per minute and avoid misidentifying low-frequency drift or high-frequency mechanical vibration as the respiratory main peak. The main peak frequency is obtained by taking the frequency corresponding to the maximum spectral value within the band. Finally, the main peak frequency is converted into the number of breaths per unit of time to obtain the respiratory rate. The conversion relationship is to multiply the main peak frequency by 60 to obtain the number of breaths per minute. This respiratory rate is used as the input for subsequent basic nebulization flow generation and target nebulization flow calculation.

[0032] S4. Generate a basic nebulization flow rate based on the breathing rate, and correct the basic nebulization flow rate using the differential pressure short-circuit index to obtain the target nebulization flow rate; In embodiments of the present invention, a baseline nebulization flow rate is generated based on the respiratory rate, and the baseline nebulization flow rate is corrected using a differential pressure short-circuit index, including: Obtain the nebulization flow boundary, reference nebulization flow rate, and reference breathing rate; Basic nebulization flow rate is generated based on respiratory rate; Specifically, the baseline nebulization flow rate refers to the target nebulization output flow rate calculated based solely on the current respiratory rate, combined with preset nebulization flow rate boundaries and reference calibration parameters, without considering the distortion caused by differential pressure short-circuit risk to the differential pressure channel. It serves as the initial adjustment benchmark for adaptive nebulization flow rate control, reflecting the changing demand for nebulization supply intensity due to changes in respiratory rate. The baseline nebulization flow rate is typically obtained by scaling the reference nebulization flow rate according to the ratio of the reference respiratory rate to the current respiratory rate and limiting it between the minimum and maximum nebulization flow rates. This ensures that when the respiratory rate increases, the baseline nebulization flow rate decreases accordingly to reduce extravasation and stimulation and improve inhalation matching, while when the respiratory rate decreases, the baseline nebulization flow rate increases accordingly to increase the effective supply during the inspiratory phase and maintain the stability of dose output.

[0033] In detail, the nebulization flow rate boundary corresponding to the nebulizer actuator is read from the device parameter storage area and used as a safety constraint. This boundary includes a minimum and a maximum nebulization flow rate. The minimum flow rate is preferably set to a lower limit that maintains stable nebulization without intermittent spraying to avoid discontinuous output and uneven dosage. The maximum flow rate is preferably set to an upper limit that, under rated power supply and rated air resistance conditions, does not cause significant splashing of the nebulized liquid or a significant increase in mask leakage to avoid ineffective loss and increased discomfort. Subsequently, a reference nebulization flow rate and a reference respiratory rate are read as calibration anchor points. The reference respiratory rate is preferably the median value of the typical range of adult resting breathing to improve versatility and reduce scaling deviations in common scenarios. The reference nebulization flow rate is preferably the stable and effective output level obtained by dose output calibration at the reference respiratory rate to ensure that the scaled result still falls within the achievable range. Furthermore, the reference respiratory rate and reference nebulization flow rate can be obtained through pre-calibration. Specifically, a baseline breathing state is selected within the typical respiratory rhythm range corresponding to the target population, and the respiratory frequency under this baseline breathing state is recorded as a reference respiratory frequency. Under this reference respiratory frequency condition, the nebulizer is adjusted to multiple candidate output levels, and the steady-state mist formation continuity, delivery rate per unit time, and leakage are detected at each candidate output level. From the candidate output levels that meet the conditions of stable mist formation, effective delivery, and controlled leakage, the flow rate corresponding to the target level is selected as the reference nebulization flow rate. The minimum nebulization flow rate is preferably the lowest flow rate value that can continuously form stable droplets without significant intermittent spraying, and the maximum nebulization flow rate is preferably the highest flow rate value that does not cause significant splashing, a significant increase in mask leakage, or a significant increase in user irritation.

[0034] After acquiring the parameters, read the respiratory rate calculated by the current sliding window and generate the basic nebulization flow rate according to the following formula: In the formula, Based on the atomization flow rate, For the atomization flow boundary, For reference respiratory rate, Respiratory rate, The limiting function is used to limit the calculated flow rate within the nebulization flow rate boundary to meet equipment capacity and safety constraints, with the square root of the ratio of the reference breathing frequency to the current breathing frequency used. This ensures that the nebulization flow rate decreases smoothly as the breathing frequency increases and increases smoothly as the breathing frequency decreases. This avoids excessive nebulization output causing leakage and stimulation when breathing becomes faster, and increases the effective supply during the inhalation phase when breathing becomes slower. At the same time, square root scaling is gentler than linear scaling, which can reduce the impact of individual differences and short-term fluctuations on the basic nebulization flow rate. Finally, the obtained basic nebulization flow rate output is used as the input for subsequent target nebulization flow rate calculation.

[0035] The attenuation ratio is obtained by multiplying the differential pressure short-circuit index by the preset short-circuit risk conservative coefficient. Subtract the attenuation ratio from the calculated value to obtain the retention ratio; The target atomization flow rate is obtained by multiplying the base atomization flow rate by the retention ratio. Specifically, the target nebulization flow rate refers to the final target value of the nebulization output flow rate determined after considering the baseline nebulization flow rate corresponding to the current respiratory rate and the differential pressure short-circuit risk level represented by the differential pressure short-circuit index. It serves as the direct control target of the nebulization actuator to guide the setting of pump speed, fan frequency, or valve opening, thereby enabling the nebulizer to achieve matched supply when the respiratory rhythm changes and to conservatively reduce the nebulization output when the differential pressure short-circuit risk caused by capillary bridging of the pressure tap is detected, in order to reduce leakage and stimulation and improve the stability of effective inhalation. The target nebulization flow rate has boundary constraints and continuous adjustability, which can maintain the same output trend as the baseline nebulization flow rate when the short-circuit risk is low and smoothly decay according to the retention ratio when the short-circuit risk is high, so that the final output meets the equipment capacity and safety requirements while avoiding control deviation caused by differential pressure signal distortion.

[0036] In detail, after each sliding window completes the differential pressure short-circuit index calculation and obtains the basic nebulized flow rate, a preset short-circuit risk conservatism coefficient is read as the conservatism intensity parameter for differential pressure short-circuit risk. The short-circuit risk conservatism coefficient is preferably set to 0.2 to 0.6 to achieve a perceptible reduction in nebulized flow rate when a short-circuit risk occurs, while avoiding excessive suppression of normal respiratory supply. Furthermore, the short-circuit risk conservatism coefficient is determined according to conservative control calibration rules. Specifically, under known respiratory rhythm conditions, operating conditions with no short-circuit risk, mild short-circuit risk, moderate short-circuit risk, and severe short-circuit risk are constructed respectively. Changes in target nebulized flow rate, delivery stability, and media leakage level are recorded under different conservatism coefficients. The coefficient that can achieve a smooth reduction in target nebulized flow rate without causing delivery interruption when the short-circuit risk increases is selected as the target conservatism coefficient. When the device is set to different treatment modes, different short-circuit risk conservatism coefficients can be pre-stored for pediatric mode, adult mode, or high humidity mode. The controller automatically calls the corresponding parameters according to the current treatment mode, so that the target nebulized flow rate can balance effective delivery and safety in different usage scenarios. The differential pressure short-circuit index is then multiplied by the short-circuit risk conservatism coefficient to obtain the attenuation ratio. The attenuation ratio represents the proportion that should be deducted from the basic nebulization flow rate within the current sliding window and increases with the increase of the differential pressure short-circuit index. To avoid the attenuation ratio exceeding one, which would cause the target nebulization flow rate to have a non-physical negative value or reverse change, it is preferable to impose an upper limit constraint on the attenuation ratio after multiplication so that it is no greater than one. Then, the value one is calculated and the attenuation ratio is subtracted to obtain the retention ratio. The retention ratio represents the proportion of the basic nebulization flow rate that can be retained at the current short-circuit risk level and decreases with the increase of short-circuit risk. Finally, the basic nebulization flow rate is multiplied by the retention ratio to obtain the target nebulization flow rate. This ensures that the target nebulization flow rate is close to the basic nebulization flow rate when the differential pressure short-circuit index is low and is proportionally reduced when the differential pressure short-circuit index increases. This avoids the unstable respiratory rate estimation caused by differential pressure short-circuit threshold events, which would push the nebulization output to an excessively high range and reduce the risk of leakage and irritation.

[0037] S5. Determine the atomization execution amount based on the target atomization flow rate; In an embodiment of the present invention, determining the atomization execution amount based on the target atomization flow rate includes: Based on the linear calibration relationship between the flow rate and execution volume of the atomizing actuator, the target atomizing flow rate is converted into the corresponding atomizing execution volume; In detail, after obtaining the target atomization flow rate, the pre-calibrated parameters of the atomization actuator are invoked to establish a linear mapping relationship between the flow rate and the execution quantity. Further, when the atomization actuator is a driving pump, the execution quantity is the pump speed. The controller converts the target atomization flow rate into a target pump speed and outputs it to the pump drive circuit based on the pre-calibrated correspondence between the pump speed and the steady-state atomization flow rate. When the atomization actuator is an air supply fan, the execution quantity is the fan frequency or fan speed. The controller converts the target atomization flow rate into a target fan frequency and outputs it to the fan drive circuit based on the pre-calibrated correspondence between the fan frequency and the steady-state atomization flow rate. When the atomization actuator is a proportional valve or a regulating valve, the execution quantity is the valve opening. The controller converts the target atomization flow rate into a target valve opening and outputs it to the valve control drive circuit based on the pre-calibrated correspondence between the valve opening and the steady-state atomization flow rate. This allows different types of atomizing actuators to achieve consistent control based on the same target atomization flow rate. Furthermore, when the equipment contains two or more atomizing actuators, the target atomization flow rate can be achieved through a coordinated allocation of primary and secondary actuators. The controller prioritizes the primary actuator in adjusting the target atomization flow rate and allocates the remaining adjustment based on the dynamic response speed, adjustable range, or current working margin of the secondary actuator. For example, when a drive pump and an air blower coexist, the drive pump can handle the primary adjustment of the atomized liquid supply intensity, while the air blower handles the secondary adjustment of the airflow delivery intensity. When a proportional valve and a blower coexist, the proportional valve can handle fine-grained flow correction, while the blower handles overall flow range adjustment. The controller calculates the corresponding execution quantity based on the calibration relationship of each actuator, and synchronously issues control commands when each execution quantity meets its respective rated boundary conditions, so that the composite actuator can also stably approach the target atomized flow rate. The calibration relationship is obtained by fitting the corresponding steady-state atomized flow rate obtained by testing multiple execution quantities under rated power supply and typical air resistance conditions. Preferably, least squares fitting is used to obtain the slope coefficient and bias coefficient, which are stored in the equipment parameter area to ensure the consistency of the conversion. The linear calibration relationship can be expressed as the target atomized flow rate equal to the slope coefficient multiplied by the execution quantity plus the bias coefficient. The controller adjusts the target atomized flow rate accordingly. The corresponding execution quantity is obtained by inverse calculation, and the inverse calculation result is subject to boundary constraints to avoid exceeding the rated capacity of the actuator. The boundary constraints are preferably based on the minimum and maximum execution quantities allowed by the actuator to prevent the pump from stopping or running at overspeed. Then, the obtained atomization execution quantity is encapsulated into a control command and sent to the atomization actuator through the control bus or drive interface to complete the execution. The atomization execution quantity can correspond to at least one of pump speed, fan frequency, or valve opening. After receiving the control command, the atomization actuator adjusts its own operating point to the corresponding execution quantity so that the actual atomization output flow rate approaches the target atomization flow rate and realizes adaptive control of atomization flow rate.

[0038] In one optional implementation, after outputting the execution quantity, the controller also reads feedback pressure information, feedback flow information, or actuator operating status information from the atomizing gas path to monitor the deviation between the actual output state and the target atomizing flow rate. When the deviation exceeds the allowable range, the execution quantity is iteratively corrected once or multiple times until the actual output state returns to the allowable range. The iterative correction can be based on a pre-stored calibration table for lookup correction, or it can be based on linear mapping results superimposed with small-step compensation amounts, thereby improving the accuracy and consistency of target atomizing flow rate control under different actuators, different power supply states, and different gas path resistance conditions.

[0039] like Figure 2 The diagram shown is a functional block diagram of an adaptive control system for nebulized flow rate based on respiratory rate detection provided in an embodiment of the present invention.

[0040] In this embodiment, the functions of each module / unit are as follows: The signal acquisition and processing module is used to acquire the upstream and downstream pressure sequences in the atomizing gas path and to filter the acquired sequences. The short-circuit identification module is used to calculate the differential pressure short-circuit index based on the degree of synchronization fluctuation between the upstream and downstream pressure tapping sequences and the differential pressure amplitude, and to generate a differential pressure short-circuit event flag based on the differential pressure short-circuit index. The respiratory rate module is used to determine the respiratory rate estimation signal based on the differential pressure short-circuit event flag, and to calculate the respiratory rate based on the respiratory rate estimation signal; The target flow module is used to generate a basic nebulization flow rate based on the breathing rate, and to correct the basic nebulization flow rate by using the differential pressure short-circuit index to obtain the target nebulization flow rate. The execution control module is used to determine the atomization execution amount based on the target atomization flow rate.

[0041] like Figure 3As shown, a resistance element 3 is installed in the atomizing gas path. The airflow flows from the upstream side to the downstream side along the airflow direction 5. An upstream pressure tap 1 is set on the upstream side, and a downstream pressure tap 2 is set on the downstream side. The upstream pressure tap 1 and the downstream pressure tap 2 are used to collect the pressure tapping on both sides of the resistance element 3 to form an upstream pressure tapping sequence and a downstream pressure tapping sequence, respectively. When the airflow carries the droplets 6, they are deposited and aggregated when passing through the contraction and expansion sections near the resistance element 3, forming a capillary bridging liquid film 4 in the local narrow area of ​​the resistance element 3. The capillary bridging liquid film 4 spans the pressure tapping domains on both sides of the resistance element 3 and produces a local connectivity effect, making the pressure fluctuations on the upstream and downstream sides more synchronous and the differential pressure fluctuation amplitude abnormally compressed. This provides a structural and physical basis for the generation of differential pressure short-circuit threshold events and is used to support the implementation of differential pressure short-circuit state determination and signal self-selection in the atomizing flow adaptive control method based on respiratory rate detection.

[0042] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for adaptive control of nebulized flow rate based on respiratory rate detection, characterized in that, include: S1. Collect the upstream and downstream pressure sequences in the atomizing gas path, and filter the collected sequences. S2. Based on the degree of synchronous fluctuation between the upstream and downstream pressure tapping sequences and the differential pressure amplitude, calculate the differential pressure short-circuit index and generate a differential pressure short-circuit event flag based on the differential pressure short-circuit index. S3. Determine the respiratory rate estimation signal based on the differential pressure short-circuit event flag, and calculate the respiratory rate based on the respiratory rate estimation signal; S4. Generate a basic nebulization flow rate based on the breathing rate, and correct the basic nebulization flow rate using the differential pressure short-circuit index to obtain the target nebulization flow rate; S5. Determine the atomization execution amount based on the target atomization flow rate.

2. The nebulization flow rate adaptive control method based on respiratory rate detection according to claim 1, characterized in that, The acquired sequence is filtered, including: The difference between the upstream and downstream pressure tapping sequences is calculated to obtain the differential pressure sequence. The upstream pressure sampling sequence, downstream pressure sampling sequence, and differential pressure sequence are bandpass filtered within a preset sliding window to obtain the upstream filtered pressure, downstream filtered pressure, and filtered differential pressure, respectively.

3. The nebulization flow adaptive control method based on respiratory rate detection according to claim 2, characterized in that, Calculating the differential pressure short-circuit index includes: Calculate the correlation coefficient between upstream filter pressure and downstream filter pressure; The statistical distribution width of the filtered differential pressure within the sliding window is used as the differential pressure amplitude. The absolute pressure amplitude is obtained by calculating the average of the statistical distribution width of the upstream filter pressure within the sliding window and the statistical distribution width of the downstream filter pressure within the sliding window. Calculate the ratio of the differential pressure amplitude to the absolute pressure amplitude, calculate the difference obtained by subtracting the ratio from the calculated value, and obtain the intermediate value by multiplying the difference by the correlation coefficient. By restricting the intermediate value to a range of zero to one, the differential pressure short-circuit index is obtained.

4. The nebulization flow adaptive control method based on respiratory rate detection according to claim 3, characterized in that, Differential pressure short-circuit event flags are generated based on the differential pressure short-circuit index, including: If the differential pressure short circuit index is greater than or equal to the preset short circuit judgment threshold, the differential pressure short circuit event flag is set to the valid state; otherwise, the differential pressure short circuit event flag is set to the invalid state.

5. The nebulization flow rate adaptive control method based on respiratory rate detection according to claim 4, characterized in that, The respiratory rate estimation signal is determined based on the differential pressure short-circuit event flag, including: When the differential pressure short-circuit event flag is in an active state, it is determined that the differential pressure signal is distorted, and the upstream filter pressure is selected as the respiratory rate estimation signal. When the differential pressure short-circuit event flag is invalid, the differential pressure signal is determined to be normal, and the filtered differential pressure is selected as the respiratory rate estimation signal.

6. The nebulization flow adaptive control method based on respiratory rate detection according to claim 5, characterized in that, Calculating respiratory rate based on respiratory rate estimation signal includes: Power spectral density analysis was performed on the respiratory rate estimation signal to obtain the power spectrum; The main peak frequency of the power spectrum is searched within the preset breathing frequency band boundary, and the main peak frequency is converted into the number of breaths per unit of time to obtain the breathing frequency.

7. The nebulization flow adaptive control method based on respiratory rate detection according to claim 1, characterized in that, The baseline nebulization flow rate is generated based on the respiratory rate, including: Obtain the minimum and maximum nebulization flow rates, reference nebulization flow rates, and reference respiratory rate; The formula for calculating the basic atomization flow rate is: In the formula, Based on the atomization flow rate, To minimize the atomization flow rate, For maximum atomization flow rate, For reference respiratory rate, Respiratory rate, For reference atomization flow rate.

8. The nebulization flow rate adaptive control method based on respiratory rate detection according to claim 7, characterized in that, The basic atomization flow rate is corrected by the differential pressure short-circuit index, including: The attenuation ratio is obtained by multiplying the differential pressure short-circuit index by the preset short-circuit risk conservative coefficient. Subtract the attenuation ratio from the calculated value to obtain the retention ratio; The target atomization flow rate is obtained by multiplying the base atomization flow rate by the retention ratio.

9. The nebulization flow rate adaptive control method based on respiratory rate detection according to claim 1, characterized in that, The atomization execution volume is determined based on the target atomization flow rate, including: Based on the linear calibration relationship between the flow rate and the execution quantity of the atomizing actuator, the target atomizing flow rate is converted into the corresponding atomizing execution quantity, wherein the atomizing execution quantity includes at least one of pump speed, fan frequency or valve opening degree.

10. An adaptive control system for nebulized flow rate based on respiratory rate detection, characterized in that, The system includes: The signal acquisition and processing module is used to acquire the upstream and downstream pressure sequences in the atomizing gas path and to filter the acquired sequences. The short-circuit identification module is used to calculate the differential pressure short-circuit index based on the degree of synchronization fluctuation between the upstream and downstream pressure tapping sequences and the differential pressure amplitude, and to generate a differential pressure short-circuit event flag based on the differential pressure short-circuit index. The respiratory rate module is used to determine the respiratory rate estimation signal based on the differential pressure short-circuit event flag, and to calculate the respiratory rate based on the respiratory rate estimation signal; The target flow module is used to generate a basic nebulization flow rate based on the breathing rate, and to correct the basic nebulization flow rate by using the differential pressure short-circuit index to obtain the target nebulization flow rate. The execution control module is used to determine the atomization execution amount based on the target atomization flow rate.

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