Medical equipment ventilation control method and system, storage medium and medical equipment

Abstract

The invention is suitable for the technical field of medical equipment, and provides a medical equipment ventilation control method and system, a storage medium and medical equipment.The method comprises the steps that initial ventilation pressure is calculated according to the target tidal volume and respiratory mechanical parameters measured through tentative ventilation, and the initial ventilation pressure is applied to pressure control ventilation of the first respiratory cycle; the actual tidal volume of each respiratory cycle is monitored in real time, and whether the target tidal volume is reached within the target inspiration time or not is judged; if not, the ventilation pressure of the next respiratory cycle is adjusted according to the actual tidal volume and the target tidal volume; if yes, whether the actual inspiration time is smaller than the target inspiration time is judged; and if the actual inspiration time is less than the target inspiration time, immediately stopping the ventilation flow rate to enter an inspiration pause stage, and dynamically adjusting the ventilation pressure of the next respiratory cycle according to the actual inspiration time and the target inspiration time of each respiratory cycle until the actual inspiration time is equal to the target inspiration time. The problem of tidal volume overshoot possibly generated under an existing pressure adjusting mechanism is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a ventilation control method and system for medical equipment, a storage medium and medical equipment. Background Art

[0002] In clinical respiratory support, the Pressure Regulated Volume Control (PRVC) breathing mode is a widely used ventilation mode, which combines the advantages of pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV), and can ensure the stability of the delivered tidal volume in real-time adjustment. Its core goal is to dynamically adjust the inspiratory pressure (Pset) to match the tidal volume (VTreal) with the preset target (VTset) in each respiratory cycle, and after each respiratory cycle, the medical device (such as a ventilator or anesthesia machine) adjusts the inspiratory pressure of the next respiratory cycle in a fixed step according to the difference between the actual tidal volume and the target tidal volume.

[0003] However, when the target tidal volume is adjusted, or the patient's lung compliance and airway resistance change dramatically, the medical device's single-cycle pressure adjustment mechanism may not be able to adapt in time, resulting in an overshoot of tidal volume delivery (that is, the actual tidal volume exceeds the target tidal volume), especially during the pressure increase process, which can easily lead to overventilation of the patient and increase the risk of medical device-related complications. At the same time, refer to Figure 5 As shown in the figure, PRVC usually uses discrete step pressure adjustment, that is, the pressure is adjusted after each respiratory cycle. This lag may lead to overventilation. In addition, the traditional PRVC is based on the data of the previous cycle when adjusting the pressure, and cannot respond immediately to changes in the current respiratory cycle. For example, during a respiratory cycle, if the patient's lung mechanics suddenly changes, the medical device needs to adjust the pressure in the next cycle. The time difference in between causes a clinically significant deviation between the actual tidal volume and the target tidal volume.

[0004] For example, if the patient's lung compliance suddenly improves, and the medical device still uses the previous higher pressure, too much tidal volume will be delivered. Or in patients with acute respiratory distress syndrome (ARDS), their lung compliance may drop sharply in a short period of time. When the system increases the pressure sharply to maintain the tidal volume to compensate for the decrease in lung compliance, it may cause the pressure to be too high in the next ventilation cycle, causing the delivered tidal volume to be significantly higher than the safety threshold, increasing the risk of lung injury.

[0005] Therefore, the technical defect of this overshoot phenomenon not only affects the stability of ventilation parameters, but also may have a negative impact on the respiratory treatment of critically ill patients. How to achieve precise control of tidal volume output and avoid overventilation has become a technical problem that needs to be solved urgently in this field. Summary of the invention

[0006] Based on this, the purpose of the present invention is to provide a ventilation control method, system, storage medium and medical device for medical equipment, so as to fundamentally solve the problem of tidal volume overshoot that may occur under the existing pressure adjustment mechanism.

[0007] A ventilation control method for medical equipment according to an embodiment of the present invention includes: Based on the target tidal volume set by the user and the respiratory mechanics parameters determined by trial ventilation, the initial ventilation pressure is calculated and applied to the pressure-controlled ventilation in the first respiratory cycle; Monitor the actual tidal volume of each respiratory cycle in real time and determine whether the target tidal volume is reached within the preset target inspiratory time; If the target tidal volume is not reached within the target inspiratory time, the ventilation pressure of the next respiratory cycle is adjusted according to the actual tidal volume and the target tidal volume; If the target tidal volume is reached within the target inspiratory time, it is determined whether the actual inspiratory time is less than the target inspiratory time; If so, the ventilation flow rate is immediately terminated and the inspiratory pause phase is entered. The ventilation pressure of the next respiratory cycle is dynamically adjusted according to the actual inspiratory time and the target inspiratory time of each respiratory cycle until the actual inspiratory time is equal to the target inspiratory time.

[0008] In addition, a ventilation control method for medical equipment according to the above embodiment of the present invention may also have the following additional technical features: Furthermore, the step of calculating the initial ventilation pressure based on the target tidal volume set by the user and the respiratory mechanics parameters measured by the trial ventilation and applying the initial ventilation pressure to the pressure-controlled ventilation in the first respiratory cycle includes: During the exploratory ventilation phase, a test flow was delivered at a constant test pressure, and the actual tidal volume, plateau pressure, peak inspiratory pressure, positive end-expiratory pressure, and peak inspiratory flow rate were monitored; The lung compliance in the respiratory mechanics parameters is calculated based on the actual tidal volume, plateau pressure, and positive end-expiratory pressure of ventilation; The airway resistance in the respiratory mechanics parameters is calculated based on the ventilation peak inspiratory pressure, platform pressure, and peak inspiratory flow rate; The initial ventilation pressure is calculated based on the target tidal volume, lung compliance, airway resistance, peak inspiratory flow rate and positive end-expiratory pressure set by the user; Pressure controlled ventilation with initial ventilation pressure loaded into the first respiratory cycle.

[0009] Furthermore, the step of adjusting the ventilation pressure of the next respiratory cycle according to the actual tidal volume and the target tidal volume includes: Calculate the tidal volume deviation between the actual tidal volume and the target tidal volume; The ventilation pressure of the next respiratory cycle is calculated and adjusted according to the ventilation pressure, tidal volume deviation value and lung compliance adjustment coefficient of the current respiratory cycle.

[0010] Furthermore, the step of dynamically adjusting the ventilation pressure of the next respiratory cycle according to the actual inspiratory time and the target inspiratory time of each respiratory cycle includes: Calculate the time deviation ratio between the actual inspiratory time and the target inspiratory time; When the time deviation ratio is greater than the first deviation ratio, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the preset adjustment coefficient of the ventilation pressure of the current respiratory cycle; When the time deviation ratio is less than the second deviation ratio, the ventilation pressure of the next breathing cycle is determined and adjusted according to the ventilation pressure of the current breathing cycle and the preset pressure step; When the time deviation ratio is less than the first deviation ratio and greater than the second deviation ratio, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the ventilation pressure of the current respiratory cycle and the time deviation ratio.

[0011] Furthermore, the method further comprises: When the user resets the new target tidal volume, the initial ventilation pressure is recalculated according to the new target tidal volume and respiratory mechanics parameters, and applied to the pressure-controlled ventilation of the next respiratory cycle; or When it is detected that the change rate of the current respiratory mechanics parameter exceeds the predetermined change rate range, the initial ventilation pressure is recalculated according to the target tidal volume and the current respiratory mechanics parameter and applied to the pressure-controlled ventilation of the next respiratory cycle.

[0012] Furthermore, the method further comprises: In all breathing cycles after the first breathing cycle, the cumulative deviation between the actual tidal volume and the target tidal volume is calculated in real time, and it is determined whether the cumulative deviation exceeds a preset deviation threshold; If so, the current breathing cycle is forcibly terminated and an alarm is triggered. At the same time, the ventilation pressure is reset to the initial ventilation pressure and tentative ventilation is restarted.

[0013] Furthermore, the method further comprises: Calculating the rate of change of the pressure adjustment amount between the ventilation pressure adjusted to the next respiratory cycle and the ventilation pressure of the current respiratory cycle, and determining whether the rate of change of the pressure adjustment amount exceeds a preset maximum rate of change; If so, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the ventilation pressure of the current respiratory cycle and the preset maximum change rate.

[0014] Another embodiment of the present invention is also intended to provide a medical device ventilation control system, the system comprising: Another embodiment of the present invention aims to provide a storage medium storing a program, which implements the ventilation control method of the medical device as described above when executed by a processor.

[0015] Another embodiment of the present invention aims to provide a medical device, comprising a memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor implements the medical device ventilation control method as described above when executing the program.

[0016] The ventilation control method for medical equipment provided by the embodiment of the present invention calculates the initial ventilation pressure according to the target tidal volume set by the user and the respiratory mechanics parameters measured by tentative ventilation, and applies it to the first respiratory cycle, so that a suitable initial pressure can be set according to the actual respiratory mechanics of the individual, avoiding the problem of excessive or insufficient initial pressure that may occur in the traditional ventilation pressure setting, thereby achieving more accurate tidal volume control; by real-time monitoring of the actual tidal volume of each respiratory cycle, and judging whether the target tidal volume is reached within the preset target inspiratory time, and the actual inspiratory time is less than the target inspiratory time, the ventilation flow rate is immediately terminated to enter the inspiratory pause stage, so that the actual tidal volume is maintained at the target tidal volume without ventilation, avoiding the problem of tidal volume overshoot caused by excessive ventilation pressure, and adjusting the ventilation pressure of the next respiratory cycle according to the difference between the actual tidal volume and the target tidal volume. This dynamic adjustment mechanism enables the medical device to continuously optimize the ventilation pressure according to the feedback of each respiratory cycle, avoiding the tidal volume deviation caused by the adjustment of the target tidal volume or the drastic change of the patient's respiratory mechanics parameters, and solving the problem of tidal volume overshoot that may occur under the existing pressure adjustment mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a flow chart of a ventilation control method for medical equipment in a first embodiment of the present invention; Figure 2 is a structural diagram of a ventilation control system for medical equipment in a second embodiment of the present invention; Figure 3 is a structural diagram of a medical device in a third embodiment of the present invention; Figure 4 A pressure and flow curve diagram for target tidal volume adjustment in the ventilation control method for medical equipment in the first embodiment of the present invention; Figure 5 A graph of pressure and flow rate adjusted for a target tidal volume in a prior art medical device; The following specific implementations will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0021] Embodiment 1 See also Figure 1 , which shows a ventilation control method for medical equipment in a first embodiment of the present invention. For the sake of convenience, only the part related to the embodiment of the present invention is shown. The ventilation control method for medical equipment provided by the embodiment of the present invention includes: Step S10, calculating the initial ventilation pressure based on the target tidal volume set by the user and the respiratory mechanics parameters measured by the trial ventilation and applying it to the pressure-controlled ventilation in the first respiratory cycle; Among them, in one embodiment of the present invention, the method is applied to medical equipment such as a ventilator or an anesthesia machine, and is an improved ventilation control method for the PRVC ventilation mode in existing medical equipment, wherein the control logic of the PRVC (Pressure Regulated Volume Control) ventilation mode is to ensure that the actual tidal volume is stable and close to the preset target tidal volume in the pressure control ventilation mode by dynamically adjusting the inspiratory pressure, wherein the tidal volume refers to the amount of gas entering or discharged from the lungs during each breath. Specifically, the medical equipment is taken as an example of a ventilator, and its specific working principle is that the medical staff pre-sets basic parameters such as the target tidal volume, respiratory frequency, inspiratory time and positive end-expiratory pressure. Further, the ventilator first delivers air at a lower pressure, monitors the patient's lung compliance and airway resistance in real time through flow and pressure sensors, and calculates the ventilation pressure required to achieve the target tidal volume. After each breath, the ventilator automatically adjusts the next inspiratory pressure (specifically, gradually adjusts it in a step-by-step manner) according to the feedback of the previous breath (such as the actual tidal volume). If the actual tidal volume is lower than the target tidal volume, the pressure is appropriately increased; if it is higher than the target value, the pressure is reduced. During the inhalation phase (i.e., the inspiratory phase), the ventilator ventilates in a pressure control mode, but by dynamically adjusting the upper limit of the pressure, the actual tidal volume outputted is ensured to be close to the target tidal volume. However, when the target tidal volume is adjusted, or the patient's lung compliance and airway resistance change, the ventilator's single-cycle pressure adjustment mechanism may not be able to adapt in time, resulting in an overshoot phenomenon in tidal volume delivery. Therefore, the embodiment of the present invention is improved based on the above-mentioned PRVC ventilation mode to solve the overshoot phenomenon in tidal volume delivery.

[0022] Specifically, the steps of calculating the initial ventilation pressure based on the target tidal volume set by the user and the respiratory mechanics parameters measured by the trial ventilation and applying the initial ventilation pressure to the pressure-controlled ventilation in the first respiratory cycle specifically include: During the exploratory ventilation phase, a test flow was delivered at a constant test pressure, and the actual tidal volume, plateau pressure, peak inspiratory pressure, positive end-expiratory pressure, and peak inspiratory flow rate were monitored; The lung compliance in the respiratory mechanics parameters is calculated based on the actual tidal volume, plateau pressure, and positive end-expiratory pressure of ventilation; The airway resistance in the respiratory mechanics parameters is calculated based on the ventilation peak inspiratory pressure, platform pressure, and peak inspiratory flow rate; The initial ventilation pressure is calculated based on the target tidal volume, lung compliance, airway resistance, peak inspiratory flow rate and positive end-expiratory pressure set by the user; Pressure controlled ventilation with initial ventilation pressure loaded into the first respiratory cycle.

[0023] Among them, when the medical device is first started to determine the respiratory mechanics parameters, it will enter the exploratory ventilation stage, which specifically includes delivering airflow to the patient's airway at a preset constant test pressure, where this pressure remains unchanged to measure the patient's lung response. During the exploratory ventilation process, the actual tidal volume, plateau pressure, positive end-expiratory pressure and peak inspiratory flow rate need to be monitored in real time, where the actual tidal volume refers to the amount of air inhaled under this constant pressure; the plateau pressure refers to the pressure value when the pressure in the airway reaches a stable level (no airflow, usually the pressure during apnea); the peak inspiratory pressure refers to the pressure value when the pressure in the airway reaches its peak value; the positive end-expiratory pressure refers to the residual pressure in the airway at the end of exhalation (to prevent lung collapse), which is usually set by the user; the peak inspiratory flow rate refers to the highest airflow rate during inspiration. Then, the data obtained through trial ventilation are used to calculate the two key respiratory mechanical parameters of the patient, namely lung compliance and airway resistance. Among them, lung compliance (C) represents the expansion capacity of the patient's lungs to airflow, that is, the volume change caused by a unit pressure change, which is specifically calculated based on the actual tidal volume, plateau pressure, and positive end-expiratory pressure. Among them, airway resistance (R) represents the resistance of the patient's gas to flow in the airway, which is specifically calculated based on the peak inspiratory pressure, plateau pressure, and peak inspiratory flow rate of ventilation. Then, the initial ventilation pressure is determined based on the obtained peak inspiratory flow rate and positive end-expiratory pressure, the calculated lung compliance and airway resistance, and the target tidal volume set by the user. Specifically, the initial ventilation pressure needs to overcome elastic resistance (related to compliance) and airway resistance (related to flow rate) at the same time, among which elastic resistance is determined by the target tidal volume and lung compliance, reflecting the pressure required for alveolar expansion. The airway resistance is determined by the peak inspiratory flow rate and airway resistance, reflecting the viscous resistance of gas flow. At the same time, the positive end-expiratory pressure is the basic pressure, which is set by the user. At this time, the initial ventilation pressure is determined according to the basic pressure composed of the above-mentioned positive end-expiratory pressure, the elastic resistance calculated by the target tidal volume and lung compliance, and the airway resistance calculated by the peak inspiratory flow rate and airway resistance. Once the initial ventilation pressure is calculated, it is loaded as the pressure control value of the first respiratory cycle to the pressure-controlled ventilation of the first respiratory cycle. The medical device controls the delivery of gas according to the calculated initial ventilation pressure to ensure that the amount of gas inhaled by the patient reaches the target tidal volume.

[0024] Furthermore, when the pressure-controlled ventilation (PCV) mode is used, at least two independent exploratory ventilations are performed, and the constant test pressure of each test is set to a different step value, and the duration of a single test is not less than five complete breathing cycles. It should be noted that the selection of the pressure level should be determined according to the patient's condition and clinical experience to avoid damage caused by excessive pressure; at the same time, the corresponding actual tidal volume, plateau pressure, positive end-expiratory pressure data and peak inspiratory flow rate are recorded after each test, and the lung compliance and airway resistance are calculated accordingly. If the error of the lung compliance or the error of the airway resistance calculated twice exceeds the preset error value (for example, 10%), the next additional test is triggered, at which time a different test pressure is used, and the middle value or weighted average value of the multiple test results is taken as the final lung compliance parameter and airway resistance parameter; and if the range (the difference between the maximum and minimum values) of the three test results still exceeds the preset range value (for example, 15%), it is determined that the airway response is abnormal (there may be nonlinear characteristics or measurement errors), and the volume control mode (VCV) is switched at this time and an alarm is triggered.

[0025] It should be pointed out that in one embodiment of the present invention, during the exploratory ventilation process, if the patient has strong spontaneous breathing, it may conflict with the ventilation of the medical device, causing discomfort and measurement errors. Therefore, when the patient's spontaneous breathing effort is detected, it is automatically switched to the synchronous ventilation mode. Specifically, during the inhalation phase of the exploratory ventilation, the airflow velocity and airway pressure are monitored, wherein the medical device is pre-set with a negative flow rate threshold and a pressure drop threshold. When it is detected that the negative airflow velocity is lower than the negative flow rate threshold (indicating that the patient actively inhales) or it is detected that the airway pressure drops by more than the pressure drop threshold, it is determined that there is spontaneous breathing effort, and then it is switched to the pressure support ventilation (PSV) mode. In the PSV mode, the medical device provides a preset pressure support level to help the patient inhale. When the patient's spontaneous breathing weakens or disappears, it automatically switches back to the original exploratory ventilation mode accordingly.

[0026] Step S20, real-time monitoring of the actual tidal volume of each respiratory cycle, and determining whether the target tidal volume is reached within a preset target inspiratory time; Among them, in one embodiment of the present invention, after determining the initial ventilation pressure and controlling the gas for the first ventilation delivery, the flow rate is calculated in real time by a flow sensor placed at the exhalation port of the medical device or between the inhalation / exhalation pipelines, and the analog signal output by the flow sensor is converted into a digital signal, and the digital signal is filtered to remove noise and interference, and the flow signal is integrated to obtain the real-time tidal volume. At this time, the actual tidal volume is monitored in real time and it is determined whether the target tidal volume is reached within the preset target inhalation time. When it is determined that the target tidal volume is not reached within the preset target inhalation time, step S30 is executed; and when it is determined that the target tidal volume is reached within the preset target inhalation time, step S40 is executed. Among them, it should be pointed out that due to sensor drift and other reasons, there may be errors in the integration result. Therefore, drift compensation is required, for example, at the beginning of each respiratory cycle, the integral value is reset to zero.

[0027] Step S30, adjusting the ventilation pressure of the next respiratory cycle according to the actual tidal volume and the target tidal volume; When the target tidal volume is not reached within the preset target inspiratory time, it means that the amount of gas inhaled by the patient is insufficient. At this time, the ventilation pressure needs to be increased accordingly to gradually increase the actual tidal volume until the target tidal volume is reached. Specifically, the step of adjusting the ventilation pressure of the next respiratory cycle according to the actual tidal volume and the target tidal volume includes: Calculate the tidal volume deviation between the actual tidal volume and the target tidal volume; The ventilation pressure of the next respiratory cycle is calculated and adjusted according to the ventilation pressure, tidal volume deviation value and lung compliance adjustment coefficient of the current respiratory cycle.

[0028] Specifically, when the actual tidal volume is less than the target tidal volume, it means that the current pressure is not enough to deliver enough tidal volume, and the ventilation pressure needs to be increased. Since the tidal volume is mainly determined by lung compliance under pressure control, lung compliance should be considered when adjusting the pressure. If the lung compliance is high (that is, the "elasticity" of the lung is good), it means that a smaller pressure change can allow the lungs to inhale or exhale more gas. If the lung compliance is low (such as lung stiffness), it means that a larger pressure change is required to allow the lungs to inhale or exhale the same amount of gas. At this time, the tidal volume increase brought by the same pressure increment is small, so a larger pressure compensation is required. At this time, the lung compliance adjustment coefficient is inversely proportional to the lung compliance. Therefore, when the lung compliance is low, the ventilation pressure adjustment amount increases, thereby more effectively compensating for the insufficient tidal volume caused by low compliance. At this time, the ventilation pressure adjustment amount is determined by the lung compliance regulation coefficient and the tidal volume deviation value. Therefore, the ventilation pressure of the next respiratory cycle is determined based on the ventilation pressure of the current respiratory cycle and the ventilation pressure adjustment amount determined by the lung compliance regulation coefficient and the tidal volume deviation value, and the ventilation pressure of the next respiratory cycle is adjusted after determination.

[0029] Step S40, determining whether the actual inhalation time is less than the target inhalation time; Among them, in one embodiment of the present invention, when it is judged that the actual inspiratory time is less than the target inspiratory time, that is, the ventilation of the target tidal volume is completed in advance, if the ventilation is continued until the target inspiratory time, the actual tidal volume will be greater than the target tidal volume. Therefore, in order to avoid the occurrence of tidal volume overshoot, it directly executes step S50; when it is judged that the actual inspiratory time is equal to the target inspiratory time, it means that it can control the actual tidal volume of ventilation in the inspiratory stage to reach the target tidal volume, and no operation is performed at this time.

[0030] Step S50, immediately terminating the ventilation flow rate and entering the inspiratory pause stage, and dynamically adjusting the ventilation pressure of the next respiratory cycle according to the actual inspiratory time and the target inspiratory time of each respiratory cycle, until the actual inspiratory time is equal to the target inspiratory time; Among them, in one embodiment of the present invention, when it is determined that the actual inspiratory time is less than the target inspiratory time, the ventilation flow rate is immediately terminated and the inspiratory pause stage is entered. At this time, when the air flow rate drops to zero, the medical device completely blocks possible residual airflow by closing the inspiratory valve and keeping the expiratory valve closed, thereby eliminating the overshoot caused by continued air delivery in traditional pressure control. Specifically, referring to Figure 4 As shown, the complete breathing cycle of the medical device includes an inspiratory phase (inspiratory stage) and an expiratory phase (expiratory stage), wherein the inspiratory phase is when the medical device delivers air to the patient, and the expiratory phase is when the patient exhales gas into the circuit. At this time, during the inspiratory stage, the pressure control is performed using a pressure-controlled ventilation mode, and when the inspiratory time is over, the medical device switches to the expiratory stage, during which the ventilation pressure drops to a plateau pressure, wherein when adjusting the tidal volume, after the current respiratory cycle ends, the ventilation pressure is adjusted in a step-wise manner based on the feedback processing of the actual tidal volume and the target tidal volume. Therefore, at the beginning of a new respiratory cycle, the medical device will apply the adjusted ventilation pressure and keep it fixed in the new cycle until the next respiratory cycle is adjusted. This design allows the pressure to be kept stable in each cycle, making it easier to estimate the tidal volume. Further reference is made to Figure 4 As shown in the figure, in pressure-controlled ventilation, the flow rate in the inspiratory phase is driven by the pressure provided by the medical device to drive the gas into the lungs. At this time, the flow rate is in the positive direction (entering the lungs). And under constant ventilation pressure, as the alveoli gradually fill, the alveolar pressure increases, and the driving pressure difference gradually decreases, resulting in a natural attenuation of the flow rate. At this time, the flow rate is always positive and the value decreases. When the target inspiratory time is reached, the medical device stops delivering air, the exhalation valve opens, and switches to the exhalation phase. In the exhalation phase, the medical device stops applying pressure, and the patient passively exhales the gas by relying on the elastic recoil force of the lungs. At this time, the flow direction is reversed (negative direction), that is, the gas flows out of the lungs.

[0031] Among them, when the ventilation flow rate is immediately terminated and the inspiratory pause stage is entered, the ventilation pressure in the airway is adjusted accordingly. Specifically, it can be directly adjusted to the ventilation pressure of the next respiratory cycle, or it can be gradually adjusted to reduce the ventilation pressure. Figure 4 As shown in the figure, when the target tidal volume is reached within the target inspiratory time and the actual inspiratory time is less than the target inspiratory time, the ventilation flow rate is immediately terminated and the inspiratory pause stage is entered. At this time, the ventilation flow rate is directly reduced to 0, and the ventilation pressure is correspondingly adjusted to the ventilation pressure of the next respiratory cycle. When the inspiratory phase of the current respiratory cycle is completed and the respiratory phase is entered, the inspiratory valve is opened and the airway pressure is maintained at the platform pressure level.

[0032] The step of dynamically adjusting the ventilation pressure of the next respiratory cycle according to the actual inspiratory time and the target inspiratory time of each respiratory cycle includes: Calculate the time deviation ratio between the actual inspiratory time and the target inspiratory time; When the time deviation ratio is greater than the first deviation ratio, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the preset adjustment coefficient of the ventilation pressure of the current respiratory cycle; When the time deviation ratio is less than the second deviation ratio, the ventilation pressure of the next breathing cycle is determined and adjusted according to the ventilation pressure of the current breathing cycle and the preset pressure step; When the time deviation ratio is less than the first deviation ratio and greater than the second deviation ratio, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the ventilation pressure of the current respiratory cycle and the time deviation ratio.

[0033] Specifically, when it is judged that the actual inspiratory time is less than the target inspiratory time, that is, the ventilation of the target tidal volume is completed in advance, if ventilation is continued until the target inspiratory time, the actual tidal volume will be greater than the target tidal volume. At this time, the pressure is too high and needs to be reduced. Specifically, the time deviation ratio between the actual inspiratory time and the target inspiratory time is first calculated, and then the time deviation ratio will be adjusted in stages. For example, when the actual inspiratory time is significantly less than the target inspiratory time, it means that the current ventilation pressure may be too high, and sufficient tidal volume is delivered in advance within the predetermined time, so the pressure needs to be greatly reduced. At this time, step adjustment is used to quickly correct the deviation; and when the deviation is medium, such as when the time deviation ratio is less than the first deviation ratio and greater than the second deviation ratio, linear adjustment (such as adjustment according to the time deviation ratio) can balance the response speed and stability and avoid overshoot. When the deviation is very small, such as when the time deviation ratio is less than the second deviation ratio, the fine-tuning mode gradually reduces the pressure according to the preset pressure step to ensure the accuracy of the adjustment and prevent pressure fluctuations from causing discomfort to the patient. Therefore, dynamic adaptability, fast response and stable pressure are achieved by quickly approaching the target with high-pressure steps when there are large deviations, and preventing oscillation with small step corrections when there are small deviations.

[0034] Among them, the above-mentioned preset adjustment coefficient is mainly determined according to the airway resistance. Specifically, the actual tidal volume reaching the target tidal volume too quickly may be related not only to the ventilation pressure, but also to the airway resistance. For example, if the airway resistance suddenly drops (such as secretion clearance), the flow rate increases at the same pressure, resulting in an increase in tidal volume. Therefore, the preset adjustment coefficient needs to consider the airway resistance factor, and the airway resistance is the dominant factor, that is, the preset adjustment coefficient is determined according to the airway resistance, and the preset adjustment coefficient is proportional to the airway resistance. Specifically, when the airway resistance is higher, the preset adjustment coefficient is larger, and the ventilation pressure is reduced to a greater extent, that is, more significant adjustments are required under high airway resistance to avoid excessive tidal volume. It should be pointed out that in other embodiments of the present invention, its preset adjustment coefficient is also related to the rate of change of lung compliance and is proportional: when the rate of change of lung compliance exceeds the preset threshold, the preset adjustment coefficient needs to be increased accordingly to accelerate the correction of ventilation pressure. That is to say, the step of determining and adjusting the ventilation pressure of the next respiratory cycle based on the preset adjustment coefficient of the ventilation pressure of the current respiratory cycle includes judging whether the rate of change of the currently measured lung compliance within a preset number of respiratory cycles exceeds a preset threshold; if so, determining the preset adjustment coefficient based on the currently measured airway resistance and the rate of change of lung compliance.

[0035] In one embodiment of the present invention, the method further comprises: When the user resets the new target tidal volume, the initial ventilation pressure is recalculated according to the new target tidal volume and respiratory mechanics parameters, and applied to the pressure-controlled ventilation of the next respiratory cycle; or When it is detected that the change rate of the current respiratory mechanics parameter exceeds the predetermined change rate range, the initial ventilation pressure is recalculated according to the target tidal volume and the current respiratory mechanics parameter and applied to the pressure-controlled ventilation of the next respiratory cycle.

[0036] Specifically, when the medical device detects that the user inputs a new target tidal volume, it performs tentative ventilation monitoring again to obtain the patient's respiratory mechanics parameters. Then, using the new target tidal volume and the current respiratory mechanics parameters, a new initial ventilation pressure is recalculated according to the same calculation method as when it was first started, and the calculated new initial ventilation pressure is set as the target pressure of pressure-controlled ventilation for the next respiratory cycle. At the beginning of the next respiratory cycle, gas will be delivered to the patient according to the new initial ventilation pressure value. At the same time, the medical device continuously monitors the patient's respiratory mechanics parameters (or periodically repeats tentative ventilation), such as using the data of each respiratory cycle to estimate the respiratory mechanics parameters in real time (for example, by analyzing the pressure-volume curve or the flow rate-volume curve) or automatically repeating a short tentative ventilation at intervals (for example, 15 minutes, 30 minutes or 1 hour) to obtain more accurate respiratory mechanics parameters. At this time, the medical device calculates the change rate of the current respiratory mechanics parameters (C and R) relative to the previous measured values ​​(for example, the results of the last tentative ventilation), and compares the calculated change rate with the preset threshold value of the respiratory mechanics parameter change rate. If the rate of change of any respiratory mechanics parameter (C or R) exceeds the corresponding predetermined rate of change range, it is determined that the patient's respiratory condition has changed significantly, and the initial ventilation pressure needs to be recalculated. At this time, the medical device uses the current target tidal volume and the latest measured current respiratory mechanics in the same calculation method as when it was first started to recalculate a new initial ventilation pressure and set it as the target ventilation pressure for pressure-controlled ventilation in the next respiratory cycle. The ventilation parameters are dynamically adjusted according to the individual differences and changes in the condition of the patient, so that changes in respiratory mechanics parameters can be responded to in a timely manner, and insufficient or excessive ventilation caused by improper parameter settings can be avoided, ensuring that ventilation therapy is always in the best state and improving the treatment effect.

[0037] In the process of continuous air delivery, the medical device not only pays attention to the deviation between the actual tidal volume and the target tidal volume of each respiratory cycle, but also accumulates and calculates these deviations. If the accumulated deviation is too large, it means that there is a persistent problem with ventilation control, and there may be air leakage, airway obstruction, sudden change in the patient's condition, etc. At this time, immediate measures need to be taken to ensure the safety of the patient. Therefore, in one embodiment of the present invention, the method also includes: In all breathing cycles after the first breathing cycle, the cumulative deviation between the actual tidal volume and the target tidal volume is calculated in real time, and it is determined whether the cumulative deviation exceeds a preset deviation threshold; If so, the current breathing cycle is forcibly terminated and an alarm is triggered. At the same time, the ventilation pressure is reset to the initial ventilation pressure and tentative ventilation is restarted.

[0038] Specifically, after each respiratory cycle, the medical device calculates the deviation between the actual tidal volume and the target tidal volume, and accumulates the deviation into a "cumulative deviation" variable. At this time, the cumulative deviation reflects the difference between the total amount of gas actually delivered to the patient and the total amount of gas expected to be delivered from the start of ventilation to the present. A preset deviation threshold is preset inside the medical device. This threshold can be an absolute value (for example, 500 mL) or a percentage of the target tidal volume (for example, 20%). After each respiratory cycle, the medical device compares the absolute value of the cumulative deviation with the preset deviation threshold. If the absolute value of the cumulative deviation exceeds the preset deviation threshold, it means that the accumulated deviation is too large, and the medical device determines that there is a serious problem and needs to take protective measures immediately. At this time, the medical device forcibly terminates the current respiratory cycle, that is, stops gas delivery immediately to prevent too much or too little gas from being delivered to the patient. At the same time, the alarm is triggered to sound and light alarms to alert medical staff. In addition, the ventilation pressure is reset and the tentative ventilation is restarted. Specifically, the ventilation pressure is reset to the initial ventilation pressure (the pressure calculated based on the initial tentative ventilation). Automatically restart a trial ventilation to re-evaluate the patient's respiratory mechanics parameters. In some cases, it is also possible to switch directly to volume control mode. It should be noted that after the protection mechanism is triggered, or after each trial ventilation is started, the medical device resets the "cumulative deviation" variable to zero and restarts the cumulative calculation. Therefore, by timely discovering and handling persistent ventilation deviations, serious consequences caused by cumulative errors can be prevented. At the same time, long-term ineffective ventilation due to air leakage, airway obstruction, sudden changes in the patient's condition, etc. can be avoided. The automatic triggering of the protection mechanism and the reset operation can reduce the burden on medical staff.

[0039] When the medical device adjusts the ventilation pressure, in order to avoid excessive pressure changes that may cause discomfort or lung damage to the patient, it is necessary to limit the speed of pressure adjustment to ensure a smooth transition of pressure. Therefore, in one embodiment of the present invention, the method further includes: Calculating the rate of change of the pressure adjustment amount between the ventilation pressure adjusted to the next respiratory cycle and the ventilation pressure of the current respiratory cycle, and determining whether the rate of change of the pressure adjustment amount exceeds a preset maximum rate of change; If so, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the ventilation pressure of the current respiratory cycle and the preset maximum change rate.

[0040] Specifically, after each respiratory cycle, the medical device calculates a preliminary pressure adjustment amount (i.e., how much pressure should be adjusted if the speed limit is not considered) based on factors such as the deviation between the actual tidal volume and the target tidal volume, the lung compliance adjustment coefficient, etc. At the same time, the medical device also records the actual pressure adjustment amount of the last time (i.e., how much pressure was actually adjusted in the last respiratory cycle). At this time, the preliminary pressure adjustment amount of this time is compared with the actual pressure adjustment amount of the last time, and the difference between the two is calculated, that is, the change in the pressure adjustment amount. At this time, the change in the pressure adjustment amount is divided by the time of the respiratory cycle (or a fixed time interval) to obtain the change rate of the pressure adjustment amount. Among them, a maximum pressure adjustment rate limit value is preset inside the medical device (for example, the pressure change does not exceed 2 cmH2O per second). At this time, the medical device compares the calculated change rate of the pressure adjustment amount with the preset maximum change rate. If the change rate of the pressure adjustment amount does not exceed the preset maximum change rate, the actual pressure adjustment amount of this time is equal to the preliminary pressure adjustment amount, and the adjustment is made according to the calculation result. If the change rate of the pressure adjustment amount exceeds the preset maximum change rate, the preliminary pressure adjustment amount needs to be limited so that its change rate does not exceed the preset maximum change rate. Specifically, the maximum allowable change allowed this time under the preset maximum change rate limit is calculated. If the absolute value of the preliminary pressure adjustment is greater than the maximum allowable change, the actual pressure adjustment is set to the maximum allowable change (and the same positive and negative signs as the preliminary pressure adjustment are maintained). If the absolute value of the preliminary pressure adjustment is less than the maximum allowable change, the actual pressure adjustment is set to the preliminary pressure adjustment. Then the ventilation pressure to be used in the next respiratory cycle is obtained by adding (or subtracting) the final determined actual pressure adjustment from the ventilation pressure of the current respiratory cycle. Then, at the beginning of the next respiratory cycle, the medical device will deliver gas to the patient according to the new ventilation pressure value. At the same time, the actual pressure adjustment of this time is recorded for the next calculation of the change rate of the pressure adjustment. At this time, the pressure adjustment rate is limited to avoid patient discomfort or lung damage caused by rapid changes in pressure, make the pressure transition smoother, improve the patient's tolerance, provide patients with more comfortable and effective ventilation support, and help reduce the fluctuation of ventilation parameters and improve control accuracy.

[0041] In summary, the ventilation control method of the medical device in the above-mentioned embodiment of the present invention calculates the initial ventilation pressure according to the target tidal volume set by the user and the respiratory mechanics parameters measured by tentative ventilation, and applies it to the first respiratory cycle, so that a suitable initial pressure can be set according to the actual respiratory mechanics of the individual, avoiding the problem of excessive or insufficient initial pressure that may occur in traditional ventilation pressure setting, thereby achieving more accurate tidal volume control; by real-time monitoring of the actual tidal volume of each respiratory cycle, and judging whether the target tidal volume is reached within the preset target inspiratory time, and the actual inspiratory time is less than When the target inspiratory time is reached, the ventilation flow rate is immediately terminated and the inspiratory pause stage is entered, so that the actual tidal volume is maintained at the target tidal volume without ventilation, avoiding the problem of tidal volume overshoot caused by excessive ventilation pressure, and adjusting the ventilation pressure of the next respiratory cycle according to the difference between the actual tidal volume and the target tidal volume. This dynamic adjustment mechanism enables the medical device to continuously optimize the ventilation pressure according to the feedback of each respiratory cycle, avoiding tidal volume deviation caused by the adjustment of the target tidal volume or the drastic changes in the patient's respiratory mechanics parameters, and solving the problem of tidal volume overshoot that may occur under the existing pressure adjustment mechanism.

[0042] Embodiment 2 See also Figure 2 , is a schematic diagram of the structure of a ventilation control system for medical equipment provided by the second embodiment of the present invention. For the sake of convenience, only the part related to the embodiment of the present invention is shown. The system includes: An initial ventilation pressure calculation module 110 is used to calculate the initial ventilation pressure according to the target tidal volume set by the user and the respiratory mechanics parameters determined by the trial ventilation, and apply it to the pressure-controlled ventilation in the first respiratory cycle; The tidal volume monitoring and judging module 120 is used to monitor the actual tidal volume of each respiratory cycle in real time and judge whether the target tidal volume is reached within the preset target inspiratory time; A first ventilation pressure adjustment module 130, configured to adjust the ventilation pressure of the next respiratory cycle according to the actual tidal volume and the target tidal volume if the target tidal volume is not reached within the target inspiratory time; An inspiratory time determination module 140 is used to determine whether the actual inspiratory time is less than the target inspiratory time if the target tidal volume is reached within the target inspiratory time; The second ventilation pressure adjustment module 150 is used to immediately terminate the ventilation flow rate and enter the inspiratory pause stage when the inspiratory time judgment module determines that the actual inspiratory time is less than the target inspiratory time, and dynamically adjust the ventilation pressure of the next respiratory cycle according to the actual inspiratory time and the target inspiratory time of each respiratory cycle until the actual inspiratory time is equal to the target inspiratory time.

[0043] Furthermore, in one embodiment of the present invention, the initial ventilation pressure calculation module 110 includes: A data monitoring unit, used to deliver a test gas flow at a constant test pressure during the trial ventilation phase, and to monitor the actual tidal volume, plateau pressure, peak inspiratory pressure, positive end-expiratory pressure, and peak inspiratory flow rate; A lung compliance calculation unit is used to calculate the lung compliance in the respiratory mechanics parameters according to the actual tidal volume, platform pressure, and positive end-expiratory pressure of ventilation; An airway resistance calculation unit, used to calculate the airway resistance in the respiratory mechanics parameters according to the ventilation peak inspiratory pressure, platform pressure, and peak inspiratory flow rate; The initial ventilation pressure calculation unit calculates the initial ventilation pressure according to the target tidal volume, lung compliance, airway resistance, peak inspiratory flow rate and positive end-expiratory pressure set by the user; Ventilation control unit for pressure-controlled ventilation with initial ventilation pressure applied to the first breathing cycle.

[0044] Furthermore, in one embodiment of the present invention, the first ventilation pressure adjustment module 130 includes: A tidal volume deviation value calculation unit, used for calculating a tidal volume deviation value between an actual tidal volume and a target tidal volume; The first ventilation pressure adjustment unit is used to calculate and adjust the ventilation pressure of the next respiratory cycle according to the ventilation pressure of the current respiratory cycle, the tidal volume deviation value and the lung compliance adjustment coefficient.

[0045] Further, in one embodiment of the present invention, the second ventilation pressure adjustment module 150 includes: A time deviation ratio calculation unit, used for calculating the time deviation ratio between the actual inspiratory time and the target inspiratory time; A second ventilation pressure adjustment unit, for determining and adjusting the ventilation pressure of the next respiratory cycle according to a preset adjustment coefficient of the ventilation pressure of the current respiratory cycle when the time deviation ratio is greater than the first deviation ratio; A third ventilation pressure adjustment unit, used for determining and adjusting the ventilation pressure of the next respiratory cycle according to the ventilation pressure of the current respiratory cycle and a preset pressure step when the time deviation ratio is less than the second deviation ratio; The fourth ventilation pressure adjustment unit is used to determine and adjust the ventilation pressure of the next respiratory cycle according to the ventilation pressure of the current respiratory cycle and the time deviation ratio when the time deviation ratio is less than the first deviation ratio and greater than the second deviation ratio.

[0046] Furthermore, in one embodiment of the present invention, the system further comprises: The first re-measurement module of the initial ventilation pressure is used to recalculate the initial ventilation pressure according to the new target tidal volume and respiratory mechanics parameters when the user resets the new target tidal volume, and apply it to the pressure-controlled ventilation of the next respiratory cycle; The second re-measurement module for the initial ventilation pressure is used to recalculate the initial ventilation pressure according to the target tidal volume and the current respiratory mechanics parameters when it is detected that the change rate of the current respiratory mechanics parameters exceeds the predetermined change rate range, and apply it to the pressure-controlled ventilation of the next respiratory cycle.

[0047] Furthermore, in one embodiment of the present invention, the system further comprises: The cumulative deviation calculation and judgment module is used to calculate the cumulative deviation between the actual tidal volume and the target tidal volume in real time in all breathing cycles after the first breathing cycle, and to judge whether the cumulative deviation exceeds a preset deviation threshold; The restart module is used to force the termination of the current breathing cycle and trigger an alarm when the cumulative deviation calculation and judgment module determines that the cumulative deviation exceeds the preset deviation threshold, and at the same time reset the ventilation pressure to the initial ventilation pressure and restart tentative ventilation.

[0048] Furthermore, in one embodiment of the present invention, the system further comprises: A change rate calculation and judgment module is used to calculate the change rate of the pressure adjustment amount between the ventilation pressure adjusted to the next respiratory cycle and the ventilation pressure of the current respiratory cycle, and to judge whether the change rate of the pressure adjustment amount exceeds a preset maximum change rate; The fifth ventilation pressure adjustment module is used to determine and adjust the ventilation pressure of the next respiratory cycle according to the ventilation pressure of the current respiratory cycle and the preset maximum change rate when the change rate calculation and judgment module determines that the change rate of the pressure adjustment amount exceeds the preset maximum change rate.

[0049] The medical equipment ventilation control system provided in the embodiment of the present invention has the same implementation principle and technical effects as those of the aforementioned method embodiment. For the sake of brief description, for matters not mentioned in the device embodiment, reference may be made to the corresponding contents in the aforementioned method embodiment.

[0050] Embodiment 3 Another aspect of the present invention also provides a medical device, see Figure 3 , shown is a medical device in the third embodiment of the present invention, including a memory 20, a processor 10, and a program 30 stored in the memory 20 and executable on the processor. When the processor 10 executes the program 30, the ventilation control method of the medical device as in the above embodiment is implemented.

[0051] In some embodiments, the processor 10 may be a central processing unit (CPU), a controller, a microcontroller, a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 20, such as executing access restriction programs.

[0052] The memory 20 includes at least one type of readable storage medium, and the readable storage medium includes a flash memory, a hard disk, a multimedia card, a card-type memory (such as an SD or DX memory, etc.), a magnetic memory, a magnetic disk, an optical disk, etc. In some embodiments, the memory 20 may be an internal storage unit of the medical device, such as a hard disk of the medical device. In other embodiments, the memory 20 may also be an external storage device of the medical device, such as a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the medical device. Further, the memory 20 may also include both an internal storage unit and an external storage device of the medical device. The memory 20 may be used not only to store application software and various types of data installed in the medical device, but also to temporarily store data that has been output or is to be output.

[0053] It should be pointed out that Figure 3 The structure shown does not constitute a limitation on the medical device. In other embodiments, the medical device may include fewer or more components than shown in the figure, or combine certain components, or arrange the components differently.

[0054] In summary, the medical device in the above embodiments of the present invention calculates the initial ventilation pressure according to the target tidal volume set by the user and the respiratory mechanics parameters measured by tentative ventilation, and applies it to the first respiratory cycle, so that a suitable initial pressure can be set according to the actual respiratory mechanics of the individual, avoiding the problem of excessive or insufficient initial pressure that may occur in the traditional ventilation pressure setting, thereby achieving more accurate tidal volume control; by real-time monitoring of the actual tidal volume of each respiratory cycle, and judging whether the target tidal volume is reached within the preset target inspiratory time, and the actual inspiratory time is less than the target inspiratory time, the ventilation flow rate is immediately terminated to enter the inspiratory pause stage, so that the actual tidal volume is maintained at the target tidal volume without ventilation, avoiding the problem of tidal volume overshoot caused by excessive ventilation pressure, and adjusting the ventilation pressure of the next respiratory cycle according to the difference between the actual tidal volume and the target tidal volume. This dynamic adjustment mechanism enables the medical device to continuously optimize the ventilation pressure according to the feedback of each respiratory cycle, avoiding the tidal volume deviation caused by the adjustment of the target tidal volume or the drastic change of the patient's respiratory mechanics parameters, and solving the problem of tidal volume overshoot that may occur under the existing pressure adjustment mechanism.

[0055] An embodiment of the present invention further provides a storage medium on which a program is stored. When the program is executed by a processor, the ventilation control method for medical equipment as described in the above embodiment is implemented.

[0056] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be assigned to different functional units or modules as needed, that is, the internal structure of the storage device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the implementation method can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application.

[0057] Those skilled in the art will appreciate that the logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be specifically implemented in any storage medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For purposes of this specification, a "storage medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0058] More specific examples of storage media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the storage medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in the memory.

[0059] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or a combination thereof: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0061] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A ventilation control method for medical equipment, characterized in that: The method comprises: Based on the target tidal volume set by the user and the respiratory mechanics parameters determined by trial ventilation, the initial ventilation pressure is calculated and applied to the pressure-controlled ventilation in the first respiratory cycle; Monitor the actual tidal volume of each respiratory cycle in real time and determine whether the target tidal volume is reached within the preset target inspiratory time; If the target tidal volume is not reached within the target inspiratory time, the ventilation pressure of the next respiratory cycle is adjusted according to the actual tidal volume and the target tidal volume; If the target tidal volume is reached within the target inspiratory time, it is determined whether the actual inspiratory time is less than the target inspiratory time; If so, the ventilation flow rate is immediately terminated and the inspiratory pause phase is entered. The ventilation pressure of the next respiratory cycle is dynamically adjusted according to the actual inspiratory time and the target inspiratory time of each respiratory cycle until the actual inspiratory time is equal to the target inspiratory time.

2. The ventilation control method for medical equipment according to claim 1, characterized in that: The step of calculating the initial ventilation pressure based on the target tidal volume set by the user and the respiratory mechanics parameters measured by the trial ventilation and applying the initial ventilation pressure to the pressure-controlled ventilation in the first respiratory cycle includes: During the exploratory ventilation phase, a test flow was delivered at a constant test pressure, and the actual tidal volume, plateau pressure, peak inspiratory pressure, positive end-expiratory pressure, and peak inspiratory flow rate were monitored; The lung compliance in the respiratory mechanics parameters is calculated based on the actual tidal volume, plateau pressure, and positive end-expiratory pressure of ventilation; The airway resistance in the respiratory mechanics parameters is calculated based on the ventilation peak inspiratory pressure, platform pressure, and peak inspiratory flow rate; The initial ventilation pressure is calculated based on the target tidal volume, lung compliance, airway resistance, peak inspiratory flow rate and positive end-expiratory pressure set by the user; Pressure controlled ventilation with initial ventilation pressure loaded into the first respiratory cycle.

3. The ventilation control method for medical equipment according to claim 1, characterized in that: The step of adjusting the ventilation pressure of the next respiratory cycle according to the actual tidal volume and the target tidal volume comprises: Calculate the tidal volume deviation between the actual tidal volume and the target tidal volume; The ventilation pressure of the next respiratory cycle is calculated and adjusted according to the ventilation pressure, tidal volume deviation value and lung compliance adjustment coefficient of the current respiratory cycle.

4. The ventilation control method for medical equipment according to claim 1, characterized in that: The step of dynamically adjusting the ventilation pressure of the next respiratory cycle according to the actual inspiratory time and the target inspiratory time of each respiratory cycle comprises: Calculate the time deviation ratio between the actual inspiratory time and the target inspiratory time; When the time deviation ratio is greater than the first deviation ratio, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the preset adjustment coefficient of the ventilation pressure of the current respiratory cycle; When the time deviation ratio is less than the second deviation ratio, the ventilation pressure of the next breathing cycle is determined and adjusted according to the ventilation pressure of the current breathing cycle and the preset pressure step; When the time deviation ratio is less than the first deviation ratio and greater than the second deviation ratio, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the ventilation pressure of the current respiratory cycle and the time deviation ratio.

5. The ventilation control method for medical equipment according to claim 1, characterized in that: The method further comprises: When the user resets the new target tidal volume, the initial ventilation pressure is recalculated according to the new target tidal volume and respiratory mechanics parameters, and applied to the pressure-controlled ventilation of the next respiratory cycle; or When it is detected that the change rate of the current respiratory mechanics parameter exceeds the predetermined change rate range, the initial ventilation pressure is recalculated according to the target tidal volume and the current respiratory mechanics parameter and applied to the pressure-controlled ventilation of the next respiratory cycle.

6. The ventilation control method for medical equipment according to claim 1, characterized in that: The method further comprises: In all breathing cycles after the first breathing cycle, the cumulative deviation between the actual tidal volume and the target tidal volume is calculated in real time, and it is determined whether the cumulative deviation exceeds a preset deviation threshold; If so, the current breathing cycle is forcibly terminated and an alarm is triggered. At the same time, the ventilation pressure is reset to the initial ventilation pressure and tentative ventilation is restarted.

7. The ventilation control method of medical equipment according to claim 1, characterized in that: The method further comprises: Calculating the rate of change of the pressure adjustment amount between the ventilation pressure adjusted to the next respiratory cycle and the ventilation pressure of the current respiratory cycle, and determining whether the rate of change of the pressure adjustment amount exceeds a preset maximum rate of change; If so, the ventilation pressure of the next respiratory cycle is determined and adjusted according to the ventilation pressure of the current respiratory cycle and the preset maximum change rate.

8. A ventilation control system for medical equipment, characterized in that: The system comprises: An initial ventilation pressure calculation module is used to calculate the initial ventilation pressure based on the target tidal volume set by the user and the respiratory mechanics parameters determined by the trial ventilation, and apply it to the pressure-controlled ventilation in the first respiratory cycle; The tidal volume monitoring and judgment module is used to monitor the actual tidal volume of each respiratory cycle in real time and judge whether the target tidal volume is reached within the preset target inspiratory time; A first ventilation pressure adjustment module, configured to adjust the ventilation pressure of the next respiratory cycle according to the actual tidal volume and the target tidal volume if the target tidal volume is not reached within the target inspiratory time; An inspiratory time judgment module is used to judge whether the actual inspiratory time is less than the target inspiratory time if the target tidal volume is reached within the target inspiratory time; The second ventilation pressure adjustment module is used to immediately terminate the ventilation flow rate and enter the inspiratory pause stage when the inspiratory time judgment module determines that the actual inspiratory time is less than the target inspiratory time, and dynamically adjust the ventilation pressure of the next respiratory cycle according to the actual inspiratory time and the target inspiratory time of each respiratory cycle until the actual inspiratory time is equal to the target inspiratory time.

9. A storage medium storing a program, characterized in that: When the program is executed by a processor, the medical device ventilation control method according to any one of claims 1 to 7 is implemented.

10. A medical device, characterized in that: The invention comprises a memory, a processor and a program stored in the memory and executable on the processor, wherein when the processor executes the program, the ventilation control method for medical equipment according to any one of claims 1 to 7 is implemented.

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