Artificial airway multi-parameter fusion monitoring and early warning method and system

Abstract

The application discloses an artificial airway multi-parameter fusion monitoring and early warning method and system, obtains airbag pressure, inhalation flow, exhalation flow and airbag upstream and downstream gas parameters in the mechanical ventilation process, divides and time-aligns according to a breathing cycle, respectively determines airbag pressure perturbation characteristics, flow non-conservation characteristics and gas state difference characteristics; the breathing cycle in which the airbag pressure perturbation characteristics deviates is taken as a starting reference cycle, a cross-cycle coupling relationship is established according to the response time delay, change direction and duration of different characteristics; when the airbag average pressure is in a safe range, periodic mechanical ventilation disturbance is identified, and the sealing degradation correlation and the airbag local sealing degradation degree are determined according to the time sequence response that continuously exists after the disturbance is excluded; when the early warning condition is met, micro-leakage early warning information is output, the influence of periodic ventilation disturbance can be reduced, and early identification of airbag local sealing degradation and micro-leakage is realized.

Description

Technical Field

[0001] This invention relates to the field of artificial airway monitoring technology, specifically to a method and system for multi-parameter fusion monitoring and early warning of artificial airways. Background Technology

[0002] Artificial airways are widely used in clinical settings such as mechanical ventilation, anesthesia, and intensive care. After an endotracheal intubation or tracheostomy tube is inserted into the patient's airway, a cuff placed around the periphery of the artificial airway is inflated and contacts the tracheal wall, forming a sealed interface between the artificial airway and the tracheal wall to maintain a relatively closed state for gas delivery during mechanical ventilation. The cuff's seal directly affects the effective delivery of airflow during mechanical ventilation; therefore, continuous monitoring of cuff pressure and the ventilation status of the artificial airway is usually required.

[0003] Current artificial airway monitoring methods primarily determine the cuff's condition by checking if the cuff pressure remains within a preset safe range, or by combining parameters such as inspiratory flow rate, expiratory flow rate, and airway pressure to determine if leakage has occurred. However, the tracheal wall cross-section does not always maintain a regular shape, and the cuff is a flexible structure. When the patient's position changes, the head and neck move, the tracheal cross-section changes, or local wrinkles form in the cuff, local areas of incomplete seal may appear between the cuff and the tracheal wall, forming microscale leakage channels. In the early stages of this leakage channel formation, the overall pressure change inside the cuff is small, and the average cuff pressure may still be within a safe range. Therefore, relying solely on cuff pressure thresholds is insufficient to promptly identify local seal degradation.

[0004] Meanwhile, during mechanical ventilation, cuff pressure, inspiratory flow rate, expiratory flow rate, and gas states upstream and downstream of the cuff all undergo periodic changes with the ventilation cycle. Patient coughing, suctioning, changes in body position, and adjustments to ventilation parameters also generate transient disturbances, making subtle abnormalities caused by local seal degradation easily confused with normal periodic fluctuations or transient changes. Existing methods for leak detection, using single parameter thresholds or simultaneous abnormalities of multiple parameters, struggle to distinguish between periodic disturbances and persistent seal degradation by utilizing the sequential response relationships of different physical parameters after the formation of microscale leaks.

[0005] In view of this, the present invention provides a method and system for multi-parameter fusion monitoring and early warning of artificial airways to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-parameter fusion monitoring and early warning method and system for artificial airways, which aims to solve the problem that it is difficult to identify local seal degradation of artificial airway airbags in a timely manner when the average pressure of the airbag is within a safe range and the micro-leakage characteristics are covered by periodic mechanical ventilation disturbances.

[0007] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for multi-parameter fusion monitoring and early warning of artificial airways, comprising the following steps: The cuff pressure, inspiratory flow rate, expiratory flow rate, and gas parameters characterizing the gas state upstream and downstream of the cuff are obtained during mechanical ventilation of the artificial airway. The cuff pressure, inspiratory flow rate, expiratory flow rate, and gas parameters are divided into periodic data corresponding to multiple respiratory cycles according to the mechanical ventilation cycle. The characteristics of airbag pressure perturbation relative to the pressure change baseline are determined based on the airbag pressure during each respiratory cycle, the characteristics of flow nonconservation are determined based on inspiratory and expiratory flow rates, and the characteristics of gas state differences across the sealing interface are determined based on upstream and downstream gas parameters of the airbag. Using the respiratory cycle in which the airbag pressure perturbation feature deviates as the initial reference cycle, the response time delay, direction of change, and duration of continuous unidirectional change of the flow non-conservation feature and gas state difference feature relative to the initial reference cycle are determined, so as to establish the cross-cycle coupling relationship between the airbag pressure perturbation feature, flow non-conservation feature, and gas state difference feature in multiple consecutive respiratory cycles. When the average pressure of the airbag is within a preset safe range, the periodic disturbance that changes synchronously with the mechanical ventilation cycle is identified according to the cross-cycle coupling relationship, and the seal degradation correlation is determined according to the time-series response relationship that persists between different features after excluding the periodic disturbance. The degree of local seal degradation of the airbag is determined based on the seal degradation correlation corresponding to multiple consecutive breathing cycles, and micro-leakage warning information is output when the degree of local seal degradation of the airbag meets the preset warning conditions.

[0008] Furthermore, the cycle boundary of each respiratory cycle is determined based on the transition time between the inspiratory and expiratory phases during mechanical ventilation, and the cuff pressure, inspiratory flow rate, expiratory flow rate, and upstream and downstream gas parameters of the cuff are time-aligned according to the cycle boundary so that different parameters correspond to the inspiratory and expiratory phases of the same respiratory cycle, respectively.

[0009] Furthermore, the pressure change baseline is determined based on the statistical values ​​or trends of the cuff pressure in several consecutive stable respiratory cycles prior to the current respiratory cycle, the deviation of the cuff pressure in the current respiratory cycle from the pressure change baseline is determined, and the normal pressure fluctuation range is determined based on the statistical distribution of the cuff pressure perturbations corresponding to consecutive stable respiratory cycles. When the airbag pressure perturbation corresponding to the current respiratory cycle exceeds the normal pressure fluctuation range, it is determined that the airbag pressure has deviated from the pressure change baseline, and the airbag pressure perturbation characteristics are determined based on at least two of the amplitude, duration, stage of occurrence, and phase position relative to the respiratory cycle of the deviation. The stable respiratory cycle is defined as a respiratory cycle in which no changes in patient position, coughing, suctioning, or mechanical ventilation parameters are detected, and the corresponding monitoring parameters do not show any continuous abnormal changes.

[0010] Furthermore, the airflow switching phase is determined based on the phase boundary between the inspiratory and expiratory phases, the flow data corresponding to the airflow switching phase is smoothed by a sliding window, and the transient flow changes generated by the airflow switching phase are excluded when determining the periodic flow difference. The cumulative inspiratory flow rate and cumulative expiratory flow rate within the same respiratory cycle are determined based on the inspiratory flow rate and expiratory flow rate after excluding the transient flow rate changes. The periodic flow rate difference is determined based on the difference between the cumulative inspiratory flow rate and the cumulative expiratory flow rate. The flow rate non-conservation characteristic is determined based on the periodic flow rate difference corresponding to multiple consecutive respiratory cycles.

[0011] Furthermore, the gas parameters include at least one of carbon dioxide concentration, humidity, and temperature, and the gas state difference characteristics are determined based on the variation amplitude, direction of variation, and timing of the corresponding gas parameters upstream and downstream of the airbag within the same respiratory cycle; The gas parameters upstream of the airbag are collected from the airway space above the airbag near the glottis, and the gas parameters downstream of the airbag are collected from the airflow channel of the artificial airway.

[0012] Furthermore, the characteristic changes of airbag pressure perturbation, flow non-conservation, and gas state difference characteristics during each respiratory cycle were determined. Using the respiratory cycle in which the airbag pressure perturbation characteristics deviate as the initial reference cycle, the current respiratory cycle or subsequent respiratory cycle in which the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction is determined, and the corresponding response time delay is determined based on the cycle interval between the respiratory cycle in which the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction and the initial reference cycle. The duration is determined by the repetition of temporal responses with the same order and corresponding direction of change among the features in multiple consecutive respiratory cycles.

[0013] Furthermore, when the airbag pressure perturbation characteristics change back and forth at similar phase positions with the mechanical ventilation cycle, and the flow non-conservation characteristics and gas state difference characteristics do not form a continuous change in the corresponding direction within multiple consecutive respiratory cycles, the corresponding change is determined as the periodic perturbation. When the airbag pressure perturbation characteristics deviate, the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction in the current respiratory cycle or subsequent respiratory cycles, and the response time delay and the corresponding change direction repeat in multiple consecutive respiratory cycles, the corresponding time-series response relationship is determined as the seal degradation association.

[0014] Furthermore, when a change in patient position, coughing, suctioning, or adjustment of mechanical ventilation parameters is detected, the corresponding respiratory cycle and the preset number of subsequent respiratory cycles are identified as perturbation cycles, so that the cycle data corresponding to the perturbation cycle are not involved in the determination of seal degradation association, or the confidence weight of the cycle data when involved in the determination of seal degradation association is reduced. After the disturbance period ends, the local seal degradation status of the airbag is reviewed based on whether the seal degradation association continues to exist in subsequent consecutive breathing cycles. When the seal degradation association disappears, the corresponding micro-leakage warning is reduced or canceled. When the seal degradation association continues to exist, the corresponding micro-leakage warning level is maintained or increased.

[0015] Furthermore, within a continuous stable respiratory cycle in which no seal degradation association is formed, the pressure change baseline is updated based on the statistical characteristics of the cuff pressure corresponding to multiple stable respiratory cycles, and the flow non-conservation baseline is updated based on the statistical characteristics of the periodic flow difference corresponding to the inspiratory flow and expiratory flow. Based on the updated pressure change baseline, determine the cuff pressure perturbation characteristics for subsequent respiratory cycles, and based on the updated flow non-conservation baseline, determine the flow non-conservation characteristics for subsequent respiratory cycles.

[0016] In a second aspect, the present invention provides a multi-parameter fusion monitoring and early warning system for artificial airways, used to execute the multi-parameter fusion monitoring and early warning method for artificial airways described in the first aspect, comprising: The airbag pressure acquisition module is used to acquire the airbag pressure during mechanical ventilation of the artificial airway; The flow acquisition module is used to acquire inspiratory and expiratory flow rates during mechanical ventilation. The gas state acquisition module is used to acquire gas parameters that characterize the gas state upstream and downstream of the airbag, respectively. The periodic data processing module is used to divide the cuff pressure, inspiratory flow rate, expiratory flow rate and gas parameters into periods according to the mechanical ventilation cycle, and to determine the cuff pressure perturbation characteristics, flow rate non-conservation characteristics and gas state difference characteristics based on the periodic data corresponding to each respiratory cycle. The fusion determination module is used to determine the response time delay, direction of change, and duration of continuous unidirectional change of the flow non-conservation feature and the gas state difference feature relative to the initial reference period, using the respiratory cycle in which the airbag pressure perturbation feature deviates as the starting reference period. It establishes cross-period coupling relationships among the airbag pressure perturbation feature, flow non-conservation feature, and gas state difference feature within multiple consecutive respiratory cycles. When the average airbag pressure is within a preset safe range, it identifies periodic disturbances that change synchronously with the mechanical ventilation cycle based on the cross-period coupling relationship. It determines the seal degradation correlation based on the continuous temporal response relationship between different features after excluding the periodic disturbance, and determines the degree of local seal degradation of the airbag based on the seal degradation correlation corresponding to multiple consecutive respiratory cycles. The early warning module is used to output micro-leakage early warning information when the degree of local seal degradation of the airbag meets the preset early warning conditions.

[0017] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention uses the mechanical ventilation respiratory cycle as a unified time reference to periodically divide and time-align cuff pressure, inspiratory flow rate, expiratory flow rate, and upstream and downstream gas parameters of the cuff, enabling correlation analysis of different physical parameters under the same respiratory stage. By extracting cuff pressure perturbation features, flow rate non-conservation features, and gas state difference features, and establishing cross-cycle coupling relationships based on the response time delay, direction of change, and duration of these three types of features in multiple consecutive respiratory cycles, the subtle changes caused by localized cuff seal degradation can be characterized by the continuous temporal response between different parameters. Furthermore, by identifying periodic perturbations that are synchronous with the mechanical ventilation cycle and do not form a continuous temporal response, the interference of normal ventilation fluctuations on the seal status judgment is reduced. Thus, it is possible to identify localized cuff seal degradation and output micro-leakage warnings when the average cuff pressure is still within a safe range and no obvious leakage has occurred, improving the timeliness and reliability of early identification of micro-leakage in artificial airways. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a schematic diagram of the artificial airway and multi-parameter monitoring location structure of the present invention; Figure 2 This is a schematic diagram showing the multi-parameter monitoring positions and the airbag sealing status when the artificial airway of the present invention is placed inside the airway; Figure 3This is a flowchart of the multi-parameter fusion monitoring and early warning method for artificial airways according to the present invention; Figure 4 This is a schematic diagram illustrating the changes in multiple parameter signals during one respiratory cycle and adjacent respiratory cycles according to the present invention. Figure 5 This is a schematic diagram illustrating the cross-cycle coupling relationship between the airbag pressure perturbation characteristics, flow non-conservation characteristics, and gas state difference characteristics within multiple consecutive respiratory cycles of the present invention. Figure 6 This is a schematic diagram illustrating the relationship between the response time delay and continuous change, based on the respiratory cycle in which the airbag pressure perturbation characteristics deviate as the initial reference cycle. Figure 7 This is a block diagram of the multi-parameter fusion monitoring and early warning system for artificial airways according to the present invention.

[0020] In the diagram: 1. Artificial airway tube; 2. Airbag; 3. Airbag inflation tube; 4. Indicator balloon; 5. Airbag pressure sensor; 6. Airbag pressure monitoring interface; 7. Inspiratory flow monitoring unit; 8. Expiratory flow monitoring unit; 9. Upstream gas parameter monitoring unit for airbag; 10. Downstream gas parameter monitoring unit for airbag; 11. Proximal interface of artificial airway; 12. Distal end of artificial airway; 13. Tracheal wall; 14. Airbag sealing interface. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are used to illustrate the technical principles and specific implementation processes of the present invention, and are not intended to limit the scope of protection of the present invention. Those skilled in the art can make adaptive adjustments to the specific implementation methods according to the type of artificial airway, mechanical ventilation mode, monitoring parameter type, and sensor configuration without departing from the technical concept of the present invention.

[0022] This invention addresses the problem that after the artificial airway cuff 2 and the irregular tracheal wall 13 form a cuff sealing interface 14, microscale leakage channels may form due to local wrinkles in the cuff 2, changes in patient position, or changes in tracheal cross-section, while the average pressure of the cuff 2 may still be within a preset safe range. Using the respiratory cycle of mechanical ventilation as a unified time reference, the invention extracts cuff pressure perturbation characteristics, flow non-conservation characteristics, and gas state difference characteristics, and establishes cross-cycle coupling relationships based on the response time delay, direction of change, and duration of these three types of characteristics in multiple consecutive respiratory cycles. When the average pressure of the cuff 2 is within the preset safe range, periodic disturbances that change synchronously with the mechanical ventilation cycle are identified and eliminated. Based on the time-series response relationships between different characteristics after eliminating periodic disturbances, a seal degradation correlation is determined. The degree of local seal degradation of the cuff 2 is determined based on the seal degradation correlation, and micro-leakage warning information is output when preset warning conditions are met.

[0023] The cross-cycle coupling relationship described in this invention is used to characterize the temporal correlation between different monitoring features determined by actual monitoring data under a unified mechanical ventilation respiratory cycle benchmark. It does not presuppose a fixed physiological causal relationship or a fixed response period between cuff pressure perturbation features, flow rate non-conservation features, and gas state difference features. The specific response time delay of each monitoring feature can be determined based on the corresponding monitoring data under different artificial airway specifications, mechanical ventilation modes, sampling frequencies, and gas parameter types.

[0024] like Figure 1 and Figure 2 As shown, the artificial airway includes an artificial airway tube 1 and an airbag 2 disposed on the periphery of the artificial airway tube 1. After the artificial airway tube 1 is inserted into the patient's airway, the airbag 2 inflates and comes into contact with the tracheal wall 13, forming an airbag sealing interface 14 between the artificial airway tube 1 and the tracheal wall 13.

[0025] The artificial airway tube 1 is equipped with an airbag inflation tube 3 that communicates with the airbag 2. The airbag inflation tube 3 is connected to an indicator balloon 4, which is used to inflate the airbag 2 and reflect the inflation status of the airbag 2. The airbag pressure sensor 5 establishes a pressure transmission relationship with the internal space of the airbag 2 through the airbag pressure monitoring interface 6, and is used to obtain the pressure signal inside the airbag 2.

[0026] An inspiratory flow monitoring unit 7 and an expiratory flow monitoring unit 8 are respectively installed on the ventilation path of the artificial airway to obtain the inspiratory and expiratory flow rates during mechanical ventilation.

[0027] An upstream gas parameter monitoring unit 9 and a downstream gas parameter monitoring unit 10 are respectively provided on both sides of the airbag sealing interface 14. The upstream gas parameter monitoring unit 9 is used to acquire gas parameters in the airway space above the airbag 2 near the glottis; the downstream gas parameter monitoring unit 10 is used to acquire gas parameters in the airflow channel inside the artificial airway tube 1 below the airbag 2. The gas parameters include at least one of carbon dioxide concentration, humidity, and temperature. The above monitoring locations are consistent with those in the current application document. Figure 1 , Figure 2 The structure shown corresponds to this.

[0028] The proximal end of the artificial airway 11 is used to connect to the mechanical ventilation tubing, and the distal end of the artificial airway 12 is located in the patient's airway to form a mechanical ventilation airflow channel.

[0029] When the air bladder 2 is normally inflated, its outer surface forms a circumferential air bladder sealing interface 14 with the tracheal wall 13. Since the cross-section of the tracheal wall 13 is not always a regular circle, and the air bladder 2 is a flexible structure, when the patient's head and neck position, tracheal cross-section, or local shape of the air bladder 2 changes, a local non-completely fitted area may form between the air bladder 2 and the tracheal wall 13, and a microscale leakage channel may be formed by the local non-completely fitted area.

[0030] In the initial stage of microscale leakage channel formation, the overall pressure change inside airbag 2 is small, so the average airbag pressure obtained by airbag pressure sensor 5 may still be within the preset safe range. Therefore, this embodiment does not take the average pressure of airbag 2 being lower than the safety lower limit as a necessary condition for local seal degradation, but further combines the temporal correlation changes of airbag pressure, inspiratory and expiratory air flow rate, and gas state parameters upstream and downstream of the airbag in multiple consecutive respiratory cycles to determine the local sealing state of airbag sealing interface 14.

[0031] Example 1 like Figure 3 As shown, this embodiment provides a multi-parameter fusion monitoring and early warning method for artificial airways, including the following steps: S101, acquire multi-parameter monitoring data and divide the cycle and align the time according to the mechanical ventilation breathing cycle. During the mechanical ventilation of the artificial airway, the airbag pressure of the airbag 2 is acquired through the airbag pressure sensor 5, the inspiratory flow rate is acquired through the inspiratory flow rate monitoring unit 7, the expiratory flow rate is acquired through the expiratory flow rate monitoring unit 8, and the gas parameters characterizing the gas state upstream and downstream of the airbag sealing interface 14 are acquired through the upstream gas parameter monitoring unit 9 and the downstream gas parameter monitoring unit 10, respectively.

[0032] The cycle boundary of each respiratory cycle is determined based on the transition time between the inspiratory and expiratory phases during mechanical ventilation. The continuously collected cuff pressure, inspiratory flow rate, expiratory flow rate, and gas parameters are then divided into cycle data corresponding to multiple respiratory cycles according to the cycle boundary.

[0033] like Figure 4 As shown, a respiratory cycle includes an inspiratory phase and an expiratory phase. Taking the start time of the current respiratory cycle as 0, and... Indicates the moment of transition between the inspiratory and expiratory phases, in Indicates the end time of the current respiratory cycle, then 0 to... Corresponding to the inhalation phase, After that This corresponds to the exhalation phase.

[0034] The monitoring data obtained by the airbag pressure sensor 5, the inspiratory flow monitoring unit 7, the expiratory flow monitoring unit 8, the upstream gas parameter monitoring unit 9, and the downstream gas parameter monitoring unit 10 are time-aligned so that the airbag pressure, inspiratory flow, expiratory flow, and upstream and downstream gas parameters of the airbag in the same respiratory cycle correspond to the same inspiratory and expiratory phases, respectively.

[0035] When different monitoring units have different sampling frequencies, the monitoring data are normalized according to a unified timestamp, so that different monitoring parameters have corresponding cycle start time, inspiratory and expiratory phase transition time and cycle end time, thereby forming cycle data under a unified respiratory cycle benchmark.

[0036] S102, based on the periodic data, determine the airbag pressure perturbation characteristics, flow non-conservation characteristics, and gas state difference characteristics respectively. For the airbag pressure obtained by the airbag pressure sensor 5, determine the pressure change baseline based on the airbag pressure statistics or change trend of several consecutive stable respiratory cycles before the current respiratory cycle, and determine the deviation of the airbag pressure in the current respiratory cycle from the pressure change baseline.

[0037] A stable respiratory cycle refers to a respiratory cycle in which no changes in patient position, coughing, suctioning, or adjustments to mechanical ventilation parameters are detected, and the corresponding monitoring parameters do not exhibit sustained abnormal changes. The number of consecutive stable respiratory cycles can be preset based on the mechanical ventilation mode and the periodic fluctuations of the monitoring parameters. For the corresponding monitoring characteristics obtained from consecutive stable respiratory cycles, the corresponding stable state range is determined based on their statistical distribution, and this stable state range is used as a reference to determine whether the corresponding characteristics in subsequent respiratory cycles deviate from their expected range.

[0038] No. The airway pressure perturbation corresponding to one respiratory cycle can be expressed as: ; in, Indicates the first The airbag pressure perturbation corresponding to each respiratory cycle; Indicates the first Characteristic values ​​of airway pressure corresponding to each respiratory cycle; Indicates the first Baseline pressure change corresponding to each respiratory cycle.

[0039] The airbag pressure characteristic value Used to characterize the current number The cuff pressure status to be evaluated within a respiratory cycle can be determined based on the peak and trough values ​​of the cuff pressure during the current respiratory cycle, representative pressure values ​​within a preset period, or the cyclical trend; the pressure change baseline The normal pressure reference state used to characterize the current respiratory cycle can be determined based on the cuff pressure statistics or trends of several consecutive stable respiratory cycles prior to the current cycle. This ensures that the cuff pressure characteristic value corresponding to the current respiratory cycle has a different evaluation meaning from the pressure change baseline used for comparison, avoiding the simultaneous use of the same current cycle statistic as both the value to be evaluated and the reference baseline.

[0040] For cuff pressure perturbations, the normal pressure fluctuation range is determined based on the statistical distribution of cuff pressure perturbations corresponding to the aforementioned continuous stable respiratory cycles. When the cuff pressure perturbation corresponding to the current respiratory cycle exceeds the normal pressure fluctuation range, it is determined that the cuff pressure has deviated from the pressure change baseline. Furthermore, the cuff pressure perturbation characteristics are determined based on at least two of the amplitude, duration, stage of occurrence, and phase position relative to the respiratory cycle. Therefore, whether the cuff pressure has deviated and whether the corresponding perturbation has abnormal significance are judged using the normal pressure fluctuation range formed under the current stable state of the monitored object as a reference, rather than using a uniform fixed value after leaving the mechanical ventilation mode and monitoring state.

[0041] In another implementation, when it is necessary to determine the cuff pressure perturbation characteristics using the relative pressure changes between different stages within the current respiratory cycle, an intra-cycle reference baseline can be formed based on the overall pressure change trend of the current respiratory cycle, and the pressure characteristic values ​​of local stages different from those used to form the reference baseline can be used as... This allows us to determine the local pressure deviation within the current cycle.

[0042] Based on the obtained airbag pressure perturbation, the airbag pressure perturbation characteristics are determined according to at least two of the following: amplitude, duration, stage of occurrence, and phase position relative to the respiratory cycle. Therefore, the airbag pressure perturbation characteristics are used to characterize the local deviation of the airbag pressure from the normal cyclic pressure variation pattern, rather than to characterize the absolute pressure magnitude of airbag 2.

[0043] Specifically, the normal fluctuation range can be determined based on the statistical distribution of the airbag pressure perturbation corresponding to a continuous and stable respiratory cycle. When the airbag pressure perturbation corresponding to the current respiratory cycle exceeds the normal fluctuation range, the duration, stage of occurrence, and phase position are considered to determine whether the airbag pressure perturbation characteristic has deviated. Therefore, the deviation judgment of the airbag pressure perturbation characteristic is determined based on the actual fluctuation of the corresponding monitored object under stable conditions, rather than solely based on the instantaneous change of a single sampling point.

[0044] For the flow data obtained by the inspiratory flow monitoring unit 7 and the expiratory flow monitoring unit 8, time integration is performed on the flow data corresponding to the inspiratory and expiratory phases within the same respiratory cycle to determine the cumulative inspiratory gas volume. Cumulative volume of exhaled gas The periodic flow difference is determined based on the difference between the two. The cumulative inspiratory gas volume and the cumulative expiratory gas volume can be expressed as follows: ; ; in, This indicates the inspiratory flow rate at the corresponding moment during the inspiratory phase. This indicates the expiratory flow rate at the corresponding moment during the expiratory phase.

[0045] No. The difference in cycle flow rate corresponding to each respiratory cycle can be expressed as: ; in, Indicates the first The difference in flow rate corresponding to each respiratory cycle is used to characterize the degree of flow rate non-conservation corresponding to that respiratory cycle. Indicates the first The cumulative inspiratory gas volume corresponding to one respiratory cycle; Indicates the first The cumulative volume of exhaled gas corresponding to one respiratory cycle.

[0046] During the transition between the inspiratory and expiratory phases, short-term transient flow rate peaks may occur due to the switching of mechanical ventilation valves or changes in airflow direction. To reduce the impact of these transient flow rate peaks on the flow rate non-conservation characteristics, the airflow switching stage is determined based on the phase boundary between the inspiratory and expiratory phases, and the flow rate data corresponding to the airflow switching stage is smoothed using a sliding window to reduce transient peaks caused by single or a small number of abnormal sampling points.

[0047] In performing the above integral calculation, transient flow rate changes identified as airflow switching phases are further excluded, and the effective inspiratory flow rate and effective expiratory flow rate after excluding the transient flow rate changes are integrated separately to obtain the cumulative inspiratory gas volume. Cumulative volume of exhaled gas Therefore, the non-conservation of flow rate mainly reflects the continuous difference between inhaled and exhaled gases during the steady ventilation phase, while reducing the impact of transient changes caused by the switching between inhalation and exhalation on the judgment of the seal status.

[0048] For the periodic flow difference, the normal flow difference range is determined based on the statistical distribution of the periodic flow difference corresponding to a continuous and stable respiratory cycle; when the periodic flow difference corresponding to the current respiratory cycle exceeds the normal flow difference range, it is determined that the flow non-conservation characteristic has deviated, and the degree of change of the flow non-conservation characteristic is characterized by the degree of deviation of the current periodic flow difference relative to the normal flow difference range.

[0049] For the gas parameters obtained by the upstream gas parameter monitoring unit 9 and the downstream gas parameter monitoring unit 10 of the airbag, the gas state difference characteristics are determined according to the change amplitude, change direction and change time of the corresponding gas parameters upstream and downstream of the airbag sealing interface 14 within the same breathing cycle.

[0050] For any given gas parameter, the first The difference in upstream and downstream gas states corresponding to one respiratory cycle can be expressed as: ; in, Indicates the first The gas state difference corresponding to each respiratory cycle; This indicates the upstream gas parameters of the airbag obtained by the upstream gas parameter monitoring unit 9. This refers to the downstream gas parameters of the airbag obtained by the downstream gas parameter monitoring unit 10. The gas state difference quantity is a basic parameter used to determine the gas state difference characteristics, which are further determined by combining the magnitude, direction, and timing of the change in the gas state difference quantity.

[0051] When the gas parameter is carbon dioxide concentration Used to characterize the difference in carbon dioxide concentration upstream and downstream of the airbag sealing interface 14; when the gas parameter is temperature or humidity. The temperature or humidity difference between the upstream and downstream sides of the airbag sealing interface 14 is determined accordingly.

[0052] When two or more gas parameters are used at the same time, the upstream and downstream state differences corresponding to each gas parameter are determined separately. The gas state difference characteristics are determined together based on the change amplitude, change direction, change time and change in multiple consecutive breathing cycles of each state difference, so as to characterize the change relationship between the gas states on both sides of the airbag sealing interface 14.

[0053] S103, using the respiratory cycle in which the airbag pressure perturbation characteristics deviate as the initial reference cycle, establishes cross-cycle coupling relationships among the three types of characteristics, such as... Figure 5 and Figure 6 As shown, the changes in airbag pressure perturbation characteristics, flow non-conservation characteristics, and gas state difference characteristics were detected over multiple consecutive respiratory cycles.

[0054] When the When the airway pressure perturbation characteristic corresponding to the first respiratory cycle deviates from the normal pressure change pattern, the first... One respiratory cycle is determined as the starting reference cycle, and the responses of flow non-conservation characteristics and gas state difference characteristics are detected backward from the starting reference cycle.

[0055] When the flow nonconservation characteristic changes in the direction corresponding to seal degradation during the initial reference period or a subsequent breathing cycle, determine the response time delay of the flow nonconservation characteristic relative to the initial reference period. When the gas state difference characteristic changes in the direction corresponding to seal degradation during the initial reference period or a subsequent breathing cycle, determine the response time delay of the gas state difference characteristic relative to the initial reference period. .

[0056] The corresponding cross-cycle time series relationship can be expressed as: ; ; in, This represents the response time delay of the flow non-conservation characteristic relative to the airbag pressure perturbation characteristic. This represents the response time delay of gas state difference characteristics relative to airbag pressure perturbation characteristics; This indicates the moment when the airbag pressure perturbation characteristics deviate from their intended form. This indicates the moment when the non-conservation of flow characteristics changes in the corresponding direction. This indicates the moment when the gas state difference characteristic changes in the corresponding direction. The response time delay can be expressed as the number of delayed respiratory cycles, or it can be determined based on the actual time when each characteristic changes accordingly.

[0057] Further determine the direction of change for the three types of characteristics. The direction of change refers to the increase, decrease, or directional shift of the corresponding characteristic value relative to its normal state or previous respiratory cycle. The specific direction of change for different gas parameters can be determined based on the gas parameters used and their monitoring locations.

[0058] When the airbag pressure perturbation characteristics deviate, and the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction during the current respiratory cycle or subsequent respiratory cycles, the corresponding response time delay and change direction are recorded as a candidate timing response.

[0059] The candidate timing response is repeatedly detected within multiple consecutive respiratory cycles, and the number of consecutive respiratory cycles in which the candidate timing response with corresponding response time delay and corresponding change direction appears is counted. The number of respiratory cycles or the corresponding duration is taken as the duration of the timing response.

[0060] Therefore, based on the response time delay, direction of change, and duration, a cross-period coupling relationship is established between the airbag pressure perturbation characteristics, flow non-conservation characteristics, and gas state difference characteristics.

[0061] The response time delay is determined based on the respiratory cycle or actual moment when each characteristic changes during the actual monitoring process, without pre-defining that flow non-conservation characteristics and gas state difference characteristics must lag by a fixed number of respiratory cycles. For different artificial airway specifications, mechanical ventilation modes, sampling frequencies, and gas parameter types, the corresponding response time delay can be obtained based on the relevant monitoring data.

[0062] Figure 5 This is used to illustrate the cross-cycle changes of three types of features in multiple consecutive respiratory cycles. Each feature curve represents the change trend of its own feature. The vertical amplitude of each curve corresponds to different physical parameters and does not mean that the three types of features have the same value or completely consistent change trajectory. Figure 5 The curves for each consecutive time period are only used to illustrate the judgment principle of cross-cycle correlation changes. In actual monitoring, the magnitude, timing and trend of the changes of the three types of characteristics are determined independently based on their respective monitoring data.

[0063] Figure 6 The diagram further illustrates that the respiratory cycle at which the airbag pressure perturbation characteristics deviate is used as a unified time reference, and the response time delay and duration are determined based on the actual changes in subsequent flow non-conservation characteristics and gas state differences. Figure 5 and Figure 6 None of these indicate that there is a pre-set fixed response period among the three types of features.

[0064] S104, based on the cross-period coupling relationship, periodic mechanical ventilation disturbances are identified, and seal degradation correlations are determined. The mechanical ventilation process itself can cause regular changes in the airbag 2 pressure, inspiratory flow rate, expiratory flow rate, and gas state parameters with the mechanical ventilation cycle. Therefore, when the average pressure of the airbag 2 obtained by the airbag pressure sensor 5 is within a preset safe range, periodic disturbances that change synchronously with the mechanical ventilation cycle are identified based on the aforementioned cross-period coupling relationship.

[0065] When the airway pressure perturbation characteristics repeatedly change at similar phase positions in multiple consecutive respiratory cycles, while the flow non-conservation characteristics and gas state difference characteristics do not form a continuous change in the corresponding direction in multiple consecutive respiratory cycles, the corresponding change is identified as a periodic mechanical ventilation perturbation.

[0066] For example, when the pressure of the cuff 2 rises and falls regularly with the alternation of the inspiratory and expiratory phases, and the inspiratory flow rate, expiratory flow rate, and gas parameters upstream and downstream of the cuff only show similar changes repeatedly within each respiratory cycle, and the flow rate non-conservation characteristics and gas state difference characteristics do not form a response time delay and corresponding change direction that repeats in multiple consecutive respiratory cycles, the corresponding changes are identified as periodic mechanical ventilation disturbances and are not used as the basis for determining the local degradation of the cuff sealing interface 14.

[0067] For characteristic changes after excluding periodic mechanical ventilation disturbances, when the cuff pressure perturbation characteristic deviates, the flow non-conservation characteristic and gas state difference characteristic change in the corresponding direction in the current respiratory cycle or subsequent respiratory cycles, and the response time delay and the corresponding change direction repeat in multiple consecutive respiratory cycles, a stable temporal response relationship is determined between different characteristics, and the corresponding temporal response relationship is determined as a seal degradation association.

[0068] Therefore, this embodiment does not require the airbag pressure perturbation feature, flow non-conservation feature, and gas state difference feature to exceed the fixed abnormal threshold at the same time. Instead, it identifies the local sealing degradation of the airbag sealing interface 14 based on whether the three types of features form a cross-cycle time-series response relationship with a stable response time delay, corresponding change direction, and duration.

[0069] Among them, the respiratory cycle in which the airbag pressure perturbation feature deviates is used as the starting reference cycle to provide a unified time reference for the cross-cycle changes of the flow non-conservation feature and the gas state difference feature; the seal degradation correlation is determined based on the temporal correlation formed by the three types of features in multiple consecutive respiratory cycles and the perturbation elimination results, and does not take the existence of a fixed physiological causal relationship between the airbag pressure perturbation feature and the other two types of features as a premise for judgment.

[0070] S105, determine the degree of local seal degradation based on the seal degradation correlation, and output micro-leakage early warning information. After obtaining the seal degradation correlation, determine the degree of local seal degradation of the airbag sealing interface 14 between the airbag 2 and the tracheal wall 13 based on the number of consecutive cycles of the seal degradation correlation, the degree of change of the flow non-conservation characteristics, and the degree of change of the gas state difference characteristics within multiple consecutive breathing cycles.

[0071] In one specific implementation, the persistence level, flow anomaly level, and gas state anomaly level can be determined based on the number of duration cycles associated with seal degradation, the degree of deviation of flow non-conservation characteristics from the corresponding steady state, and the degree of deviation of gas state difference characteristics from the corresponding steady state, respectively. The degree of local seal degradation can then be determined based on the combination of the above levels.

[0072] For example, the level of local seal degradation can be determined based on whether each indicator reaches the corresponding preset level range. When the seal degradation correlation has appeared in multiple consecutive breathing cycles, but the degree of change in the flow non-conservation characteristics and gas state difference characteristics is still at a low level, the airbag sealing interface 14 is determined to be in an early local seal degradation state, and a first-level micro-leakage warning is output.

[0073] When the number of cycles associated with seal degradation increases further, or when at least one of the flow non-conservation characteristics and gas state difference characteristics reaches a higher level of abnormality, the degree of local seal degradation of the airbag sealing interface 14 is determined to be increased, and a second-level micro-leakage warning is output.

[0074] The aforementioned risk level ranges can be predetermined based on the specifications of the artificial airway, the mechanical ventilation mode, and the statistical distribution of corresponding characteristics under stable conditions. The specific number of different levels is not limited to two levels and can be set according to actual warning needs.

[0075] Therefore, when the average pressure of the airbag 2 obtained by the airbag pressure sensor 5 is still within the preset safe range and no obvious air leakage has occurred, the early local degradation of the airbag sealing interface 14 can be identified and a micro-leakage warning can be output based on the cross-cycle time-series response that exists continuously between different physical parameters.

[0076] To reduce the impact of transient disturbances caused by changes in patient position, coughing, suctioning, or adjustments to mechanical ventilation parameters on the assessment of seal degradation, when a change in patient position, coughing, suctioning, or adjustments to mechanical ventilation parameters are detected, the corresponding respiratory cycle and the preset number of respiratory cycles thereafter are defined as the disturbance cycle.

[0077] In one implementation, the periodic data corresponding to the disturbance period is excluded from the determination of the seal degradation association, thereby preventing transient feature changes caused by patient physiological actions or clinical operations from being identified as persistent seal degradation.

[0078] In another implementation, the confidence weight of the data corresponding to the perturbation cycle can be reduced, causing it to participate in the seal degradation association determination with a lower weight than the data of the normal respiratory cycle. With this implementation, the corresponding seal degradation association is only confirmed after a stable cross-cycle temporal response relationship is re-established in subsequent normal respiratory cycles.

[0079] After the disturbance period ends, the local seal degradation status of the airbag is reviewed based on whether the seal degradation association continues to exist in subsequent normal breathing cycles.

[0080] When the original seal degradation correlation disappears after the disturbance period ends, it indicates that the corresponding characteristic change is related to the transient disturbance, and the corresponding micro-leakage warning is reduced or canceled; when the seal degradation correlation continues to exist after the disturbance period ends, the corresponding micro-leakage warning level is maintained or increased.

[0081] To reduce the zero-point drift of the cuff pressure sensor 5, inspiratory flow monitoring unit 7, and expiratory flow monitoring unit 8, as well as the impact of slow changes in patient airway resistance or long-term changes in mechanical ventilation status on the judgment of seal status, the monitoring baseline is adaptively updated within a continuous and stable respiratory cycle in which no seal degradation correlation is formed.

[0082] Preferably, respiratory cycles that have been identified as perturbation cycles are further excluded from the continuous stable respiratory cycles that have not formed a seal degradation association, and baseline updates are performed only using stable respiratory cycle data that have not formed a seal degradation association and have not been identified as perturbation cycles.

[0083] Specifically, the pressure change baseline is updated based on the statistical mean or trend of cuff pressure corresponding to multiple consecutive stable respiratory cycles; the flow non-conservation baseline is updated based on the statistical value or trend of the periodic flow difference corresponding to multiple consecutive stable respiratory cycles.

[0084] During subsequent respiratory cycles, the characteristics of airway pressure perturbation are determined based on the updated pressure change baseline, and the degree of deviation of the current cycle flow difference from the steady state is determined based on the updated flow non-conservation baseline.

[0085] The baseline update uses only stable respiratory cycle data that have not formed a seal degradation association and have not been identified as a disturbance cycle. It does not use cycle data that have formed a persistent seal degradation association for normal baseline update, in order to reduce the possibility that persistent anomalies caused by real local seal degradation will be absorbed into the normal baseline.

[0086] Through the above processing, this embodiment, while ensuring that the average pressure of the cuff 2 remains within a preset safe range, does not rely on any single parameter of the cuff pressure, flow rate, or gas parameters exceeding a fixed abnormal threshold. Instead, under a unified mechanical ventilation respiratory cycle benchmark, it establishes a cross-cycle coupling relationship based on the response time delay, direction of change, and duration of the cuff pressure perturbation characteristics, flow rate non-conservation characteristics, and gas state difference characteristics. By identifying periodic mechanical ventilation disturbances and transient disturbances caused by patient physiological movements or clinical operations, it determines a stable seal degradation correlation from the characteristic changes of multiple consecutive respiratory cycles and further determines the degree of local seal degradation of the cuff sealing interface 14, thereby achieving early warning of micro-leakage.

[0087] Example 2 like Figure 7 As shown, this embodiment provides a multi-parameter fusion monitoring and early warning system for artificial airways, used to execute the multi-parameter fusion monitoring and early warning method for artificial airways described in Embodiment 1, including an airbag pressure acquisition module, a flow acquisition module, a gas state acquisition module, a periodic data processing module, a fusion judgment module, and an early warning module.

[0088] The airbag pressure acquisition module is connected to the airbag pressure sensor 5 to acquire the pressure signal inside the airbag 2. The airbag pressure sensor 5 establishes a pressure transmission relationship with the airbag inflation tube 3 through the airbag pressure monitoring interface 6, thereby obtaining the airbag pressure inside the airbag 2.

[0089] The flow acquisition module is connected to the inspiratory flow monitoring unit 7 and the expiratory flow monitoring unit 8 respectively, and is used to acquire the inspiratory flow and expiratory flow during the mechanical ventilation process of the artificial airway, and transmit the corresponding flow data to the periodic data processing module.

[0090] The gas state acquisition module is connected to the upstream gas parameter monitoring unit 9 and the downstream gas parameter monitoring unit 10 of the airbag, respectively, to acquire gas parameters upstream and downstream of the airbag sealing interface 14. The gas parameters include at least one of carbon dioxide concentration, humidity, and temperature.

[0091] The monitoring signals obtained by each acquisition module are input into the periodic data processing module after signal conditioning and time synchronization. The signal conditioning may include at least one of amplification, filtering, analog-to-digital conversion, and abnormal sampling value processing; the time synchronization is used to correspond the monitoring data obtained by different acquisition modules to a unified mechanical ventilation time reference.

[0092] The periodic data processing module is used to divide and align the cuff pressure, inspiratory flow, expiratory flow and gas parameters according to the mechanical ventilation cycle, and to determine the cuff pressure perturbation characteristics, flow non-conservation characteristics and gas state difference characteristics based on the periodic data corresponding to each respiratory cycle.

[0093] When determining the airbag pressure perturbation characteristics, the periodic data processing module determines the pressure change baseline based on the airbag pressure statistics or change trends of several consecutive stable respiratory cycles before the current respiratory cycle, and determines the airbag pressure perturbation characteristics based on the deviation between the airbag pressure characteristic value corresponding to the current respiratory cycle and the pressure change baseline.

[0094] When determining the flow non-conservation characteristic, the periodic data processing module identifies the airflow switching phase based on the phase boundary between the inspiratory and expiratory phases, smooths the flow data during the airflow switching phase, and excludes transient flow changes corresponding to the airflow switching phase when determining the periodic flow difference. The periodic data processing module integrates the effective inspiratory flow and effective expiratory flow over time to obtain the cumulative inspiratory gas volume and cumulative expiratory gas volume, and determines the periodic flow difference and the corresponding flow non-conservation characteristic based on the difference between the two.

[0095] The periodic data processing module further constructs a feature sequence based on the period number of each respiratory cycle, so that the airbag pressure perturbation features, flow non-conservation features, and gas state difference features corresponding to multiple consecutive respiratory cycles are arranged according to the same respiratory cycle benchmark, and the feature sequence is transmitted to the fusion determination module.

[0096] The fusion determination module is used to take the respiratory cycle in which the airbag pressure perturbation characteristics deviate as the starting reference cycle, determine the response time delay based on the respiratory cycle or the actual time when the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction, and determine the duration based on the change direction of different characteristics and the repetition of candidate timing responses in multiple consecutive respiratory cycles.

[0097] To further explain, the fusion judgment module determines the response time delay based on actual monitoring data, without pre-limiting the flow non-conservation feature and gas state difference feature to have a fixed number of lag breathing cycles relative to the airbag pressure perturbation feature; and forms a cross-cycle coupling relationship between the three types of features based on the response time delay, the corresponding change direction, and the degree of persistence.

[0098] When the average pressure of airbag 2 is within a preset safe range, the fusion judgment module identifies periodic mechanical ventilation disturbances that change synchronously with the mechanical ventilation cycle and do not form a stable and continuous temporal response, based on the cross-cycle coupling relationship.

[0099] For characteristic changes after excluding periodic mechanical ventilation disturbances, when the characteristics of airbag pressure perturbation, flow non-conservation, and gas state difference change in a preset order in the direction corresponding to seal degradation, and the corresponding time-series response persists for multiple consecutive respiratory cycles, the fusion judgment module determines the corresponding cross-cycle time-series response as seal degradation correlation.

[0100] The fusion judgment module further determines the degree of local sealing degradation of the airbag sealing interface 14 between the airbag 2 and the tracheal wall 13 based on the number of continuous cycles associated with sealing degradation, the degree of change of flow non-conservation characteristics, and the degree of change of gas state difference characteristics.

[0101] The fusion judgment module is also used to perform transient disturbance elimination and verification. When a change in patient position, coughing, suctioning, or adjustment of mechanical ventilation parameters is detected, the corresponding respiratory cycle and the preset number of subsequent respiratory cycles are identified as disturbance cycles, and the data of the corresponding cycle are excluded from the determination of seal degradation association. After the disturbance cycle ends, the local seal degradation status is verified based on whether the seal degradation association continues to exist within multiple consecutive normal respiratory cycles.

[0102] The periodic data processing module or fusion determination module can also perform adaptive updates to the monitoring baseline. Within a continuous stable respiratory cycle in which no seal degradation correlation is formed and no perturbation cycle is identified, the pressure change baseline is updated based on the statistical characteristics of the cuff pressure, and the flow non-conservation baseline is updated based on the statistical difference between the cumulative inspiratory flow and the cumulative expiratory flow, so that the cuff pressure perturbation characteristics and flow non-conservation characteristics can be re-determined in subsequent respiratory cycles.

[0103] The early warning module is connected to the fusion judgment module and is used to output micro-leakage early warning information when the degree of local seal degradation of airbag 2 meets the preset early warning conditions. Depending on the degree of local seal degradation, the early warning module can output micro-leakage early warning information of different levels.

[0104] In one specific implementation, the system further includes a data storage module. The data storage module is used to store the original monitoring data corresponding to the airbag pressure, inspiratory flow rate, expiratory flow rate, and gas parameters, as well as the periodic data formed after period division, airbag pressure perturbation characteristics, flow rate non-conservation characteristics, gas state difference characteristics, seal degradation correlation, and corresponding early warning records, for subsequent querying or to trace the sealing state change process of the airbag sealing interface 14.

[0105] The system can also be equipped with a result display module to display the real-time changing trends of airbag pressure, inspiratory flow rate, expiratory flow rate, gas state parameters, as well as the degree of local seal degradation and micro-leakage warning status; it can also be equipped with an external system interface to send micro-leakage warning information to monitoring equipment or other medical information systems.

[0106] Through the above system, the multi-parameter monitoring data obtained by the airbag pressure sensor 5, inspiratory flow monitoring unit 7, expiratory flow monitoring unit 8, upstream gas parameter monitoring unit 9, and downstream gas parameter monitoring unit 10 are no longer independently judged by a single threshold. Instead, a cross-cycle coupling relationship is established under a unified mechanical ventilation breathing cycle benchmark. The local sealing degradation of the airbag sealing interface 14 is determined based on the continuous temporal response between different characteristics. Combined with periodic disturbance elimination, transient disturbance verification, and monitoring baseline update under stable conditions, early warning of micro-leakage is achieved when the average pressure of airbag 2 has not yet shown obvious abnormalities.

[0107] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A method for multi-parameter fusion monitoring and early warning of artificial airways, characterized in that, Includes the following steps: The cuff pressure, inspiratory flow rate, expiratory flow rate, and gas parameters characterizing the gas state upstream and downstream of the cuff are obtained during mechanical ventilation of the artificial airway. The cuff pressure, inspiratory flow rate, expiratory flow rate, and gas parameters are divided into periodic data corresponding to multiple respiratory cycles according to the mechanical ventilation cycle. The characteristics of airbag pressure perturbation relative to the pressure change baseline are determined based on the airbag pressure during each respiratory cycle, the characteristics of flow nonconservation are determined based on inspiratory and expiratory flow rates, and the characteristics of gas state differences across the sealing interface are determined based on upstream and downstream gas parameters of the airbag. Using the respiratory cycle in which the airbag pressure perturbation feature deviates as the initial reference cycle, the response time delay, direction of change, and duration of continuous unidirectional change of the flow non-conservation feature and gas state difference feature relative to the initial reference cycle are determined, so as to establish the cross-cycle coupling relationship between the airbag pressure perturbation feature, flow non-conservation feature, and gas state difference feature in multiple consecutive respiratory cycles. When the average pressure of the airbag is within a preset safe range, the periodic disturbance that changes synchronously with the mechanical ventilation cycle is identified according to the cross-cycle coupling relationship, and the seal degradation correlation is determined according to the time-series response relationship that persists between different features after excluding the periodic disturbance. The degree of local seal degradation of the airbag is determined based on the seal degradation correlation corresponding to multiple consecutive breathing cycles, and micro-leakage warning information is output when the degree of local seal degradation of the airbag meets the preset warning conditions.

2. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 1, characterized in that, The cycle boundary of each respiratory cycle is determined based on the transition time between the inspiratory and expiratory phases during mechanical ventilation. The cuff pressure, inspiratory flow rate, expiratory flow rate, and upstream and downstream gas parameters of the cuff are time-aligned according to the cycle boundary so that different parameters correspond to the inspiratory and expiratory phases of the same respiratory cycle, respectively.

3. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 1, characterized in that, The pressure change baseline is determined based on the statistical values ​​or trends of the cuff pressure in several consecutive stable respiratory cycles prior to the current respiratory cycle. The deviation of the cuff pressure in the current respiratory cycle from the pressure change baseline is determined, and the normal pressure fluctuation range is determined based on the statistical distribution of the cuff pressure perturbations corresponding to consecutive stable respiratory cycles. When the airbag pressure perturbation corresponding to the current respiratory cycle exceeds the normal pressure fluctuation range, it is determined that the airbag pressure has deviated from the pressure change baseline, and the airbag pressure perturbation characteristics are determined based on at least two of the amplitude, duration, stage of occurrence, and phase position relative to the respiratory cycle of the deviation. The stable respiratory cycle is defined as a respiratory cycle in which no changes in patient position, coughing, suctioning, or mechanical ventilation parameters are detected, and the corresponding monitoring parameters do not show any continuous abnormal changes.

4. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 1, characterized in that, The airflow switching phase is determined based on the phase boundary between the inspiratory and expiratory phases. The flow data corresponding to the airflow switching phase is smoothed by a sliding window, and the transient flow changes generated by the airflow switching phase are excluded when determining the periodic flow difference. The cumulative inspiratory flow rate and cumulative expiratory flow rate within the same respiratory cycle are determined based on the inspiratory flow rate and expiratory flow rate after excluding the transient flow rate changes. The periodic flow rate difference is determined based on the difference between the cumulative inspiratory flow rate and the cumulative expiratory flow rate. The flow rate non-conservation characteristic is determined based on the periodic flow rate difference corresponding to multiple consecutive respiratory cycles.

5. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 1, characterized in that, The gas parameters include at least one of carbon dioxide concentration, humidity and temperature. The gas state difference characteristics are determined based on the change amplitude, change direction and change time of the corresponding gas parameters upstream and downstream of the airbag within the same respiratory cycle. The gas parameters upstream of the airbag are collected from the airway space above the airbag near the glottis, and the gas parameters downstream of the airbag are collected from the airflow channel of the artificial airway.

6. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 1, characterized in that, The timing of characteristic changes in the characteristics of airbag pressure perturbation, flow nonconservation, and gas state difference during each respiratory cycle was determined. Using the respiratory cycle in which the airbag pressure perturbation characteristics deviate as the initial reference cycle, the current respiratory cycle or subsequent respiratory cycle in which the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction is determined, and the corresponding response time delay is determined based on the cycle interval between the respiratory cycle in which the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction and the initial reference cycle. The duration is determined by the repetition of temporal responses with the same order and corresponding direction of change among the features in multiple consecutive respiratory cycles.

7. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 6, characterized in that, When the airbag pressure perturbation characteristics change back and forth at similar phase positions with the mechanical ventilation cycle, and the flow non-conservation characteristics and gas state difference characteristics do not form a continuous change in the corresponding direction in multiple consecutive respiratory cycles, the corresponding change is determined as the periodic perturbation. When the airbag pressure perturbation characteristics deviate, the flow non-conservation characteristics and gas state difference characteristics change in the corresponding direction in the current respiratory cycle or subsequent respiratory cycles, and the response time delay and the corresponding change direction repeat in multiple consecutive respiratory cycles, the corresponding time-series response relationship is determined as the seal degradation association.

8. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 7, characterized in that, When a change in patient position, cough, suctioning procedure, or adjustment of mechanical ventilation parameters is detected, the corresponding respiratory cycle and the preset number of respiratory cycles thereafter are identified as perturbation cycles. This prevents the cycle data corresponding to the perturbation cycles from participating in the determination of seal degradation correlation, or reduces the confidence weight of the cycle data when participating in the determination of seal degradation correlation. After the disturbance period ends, the local seal degradation status of the airbag is reviewed based on whether the seal degradation association continues to exist in subsequent consecutive breathing cycles. When the seal degradation association disappears, the corresponding micro-leakage warning is reduced or canceled. When the seal degradation association continues to exist, the corresponding micro-leakage warning level is maintained or increased.

9. The method for multi-parameter fusion monitoring and early warning of artificial airways according to claim 1, characterized in that, Within a continuous stable respiratory cycle in which no seal degradation association is formed, the pressure change baseline is updated based on the statistical characteristics of the cuff pressure corresponding to multiple stable respiratory cycles, and the flow non-conservation baseline is updated based on the statistical characteristics of the periodic flow difference corresponding to the inspiratory flow and expiratory flow. Based on the updated pressure change baseline, determine the cuff pressure perturbation characteristics for subsequent respiratory cycles, and based on the updated flow non-conservation baseline, determine the flow non-conservation characteristics for subsequent respiratory cycles.

10. A multi-parameter fusion monitoring and early warning system for artificial airways, used to execute the multi-parameter fusion monitoring and early warning method for artificial airways according to any one of claims 1 to 9, characterized in that, include: The airbag pressure acquisition module is used to acquire the airbag pressure during mechanical ventilation of the artificial airway; The flow acquisition module is used to acquire inspiratory and expiratory flow rates during mechanical ventilation. The gas state acquisition module is used to acquire gas parameters that characterize the gas state upstream and downstream of the airbag, respectively. The periodic data processing module is used to divide the cuff pressure, inspiratory flow rate, expiratory flow rate and gas parameters into periods according to the mechanical ventilation cycle, and to determine the cuff pressure perturbation characteristics, flow rate non-conservation characteristics and gas state difference characteristics based on the periodic data corresponding to each respiratory cycle. The fusion determination module is used to determine the response time delay, direction of change, and duration of continuous unidirectional change of the flow non-conservation feature and the gas state difference feature relative to the initial reference period, using the respiratory cycle in which the airbag pressure perturbation feature deviates as the starting reference period. It establishes cross-period coupling relationships among the airbag pressure perturbation feature, flow non-conservation feature, and gas state difference feature within multiple consecutive respiratory cycles. When the average airbag pressure is within a preset safe range, it identifies periodic disturbances that change synchronously with the mechanical ventilation cycle based on the cross-period coupling relationship. It determines the seal degradation correlation based on the continuous temporal response relationship between different features after excluding the periodic disturbance, and determines the degree of local seal degradation of the airbag based on the seal degradation correlation corresponding to multiple consecutive respiratory cycles. The early warning module is used to output micro-leakage early warning information when the degree of local seal degradation of the airbag meets the preset early warning conditions.

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