Dynamic estimation method and system for airway resistance of respiratory support equipment and medium

Abstract

The invention discloses a dynamic estimation method for airway resistance of respiratory support equipment. The dynamic estimation method comprises the following steps that the tidal volume, the flow change value and the expiration and inspiration pressure difference of the respiratory support equipment are obtained; based on the inspiration tidal volume of the unit inspiration time, the flow change value of the unit expiration time and the pressure difference between the unit inspiration time and the unit expiration time, an air path patency evaluation model is built, and air path patency is calculated according to the air path patency model; and fitting the air passage smoothness evaluation model to obtain a fitting model of the air passage resistance and the air passage smoothness, and calculating the air passage resistance of the respiratory support equipment according to the fitting model. The technical problem of how to accurately and quickly estimate the airway resistance and output the result in the autonomous dual-level mode is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of respiratory support equipment, and in particular to a method, system and medium for dynamically estimating airway resistance of respiratory support equipment. Background Art

[0002] Respiratory support equipment is a device that assists breathing by inhaling gas, without the need to make skin incisions, and is suitable for ventilation disorders caused by a variety of reasons. Respiratory support equipment uses the principle of air pressure difference to provide stable positive pressure support while the patient is sleeping, improve upper airway collapse, increase alveolar expansion, and improve ventilation-perfusion ratio. The use of respiratory support equipment helps improve sleep quality and reduce hypoxemia caused by obstructive sleep apnea. Respiratory support equipment can be used to relieve symptoms such as dyspnea, nocturnal snoring, and daytime sleepiness caused by chronic obstructive pulmonary disease. For medical staff, the relevant parameters of respiratory support equipment can be adjusted according to airway resistance to provide better mechanical ventilation. For respiratory support equipment manufacturers, if the air resistance of respiratory support equipment can be accurately estimated, relevant references can be provided for pressure control of respiratory support equipment. Therefore, the estimation of airway resistance is of great significance to the application and development of respiratory support equipment. The patent document with application number 201610740141.6 discloses a medical respiratory support device and a method for continuously measuring airway resistance and compliance thereof. Adding an amplitude, frequency and duration to the pressure level of the positive airway pressure ventilation mode can adjust the high-frequency oscillation pressure, and measure the airway resistance of the respiratory system by the high-frequency oscillation pressure and flow. The patent document with application number 202110586659.X discloses a method for online measurement of airway resistance and compliance of a non-invasive positive pressure respiratory support device, which provides a pressure pulse at the end of the patient's exhalation, and obtains the lung deflation flow of the user at each moment within the time end by flow detection and leakage calculation, thereby calculating the airway resistance. The above methods all require specific conditions, either a high-frequency ventilation mode, or the patient deliberately prolongs the exhalation time during the ventilation process, and have obvious limitations in the autonomous dual-level mode. Therefore, it is urgent to provide a method, system and medium for dynamically estimating the airway resistance of a respiratory support device to solve the technical problem of how to accurately and quickly estimate the airway resistance and output the results in the autonomous dual-level mode. Summary of the invention

[0003] The main purpose of the present invention is to propose a method, system and medium for dynamically estimating airway resistance of a respiratory support device, aiming to solve the technical problem of how to accurately and quickly estimate airway resistance and output the results in an autonomous dual-level mode.

[0004] To achieve the above object, according to one aspect of the present invention, the present invention provides a method for dynamically estimating airway resistance of a respiratory support device, wherein the method for dynamically estimating airway resistance of a respiratory support device comprises the following steps:

[0005] S1. Obtain the tidal volume, flow change value, and pressure difference between exhalation and inspiration of the respiratory support equipment;

[0006] S2. constructing an airway patency assessment model based on the inspiratory tidal volume per unit inspiratory time, the flow rate change value per unit expiratory time, and the pressure difference between the unit inspiratory time and the unit expiratory time, and calculating the airway patency according to the airway patency model;

[0007] S3. Fitting the airway patency assessment model to obtain a fitting model of airway resistance and airway patency, and calculating the airway resistance of the respiratory support device according to the fitting model.

[0008] In one of the preferred embodiments, the inspiratory tidal volume is the inspiratory tidal volume per unit inspiratory time of the respiratory support device.

[0009] In one of the preferred solutions, the flow change value is the flow change value per unit exhalation time during the exhalation phase, and the flow change value is strongly negatively correlated with the compliance of the respiratory support device.

[0010] In one of the preferred embodiments, the pressure difference is:

[0011] ΔP=P 1 -P 2

[0012] Where ΔP is the pressure difference between unit inspiration time and unit expiration time, P 1 is the maximum pressure reached during inspiration, P 2 It is the minimum pressure during exhalation.

[0013] In one of the preferred embodiments, the airway patency assessment model is:

[0014]

[0015] Among them, Patency is the patency of the airway, ΔF is the flow change value per unit expiratory time, V is the inspiratory tidal volume, ΔP is the pressure difference between exhalation and inspiration, and t is the inspiratory time.

[0016] In one of the preferred embodiments, the unit exhalation time is 100 ms.

[0017] In one of the preferred embodiments, the fitting model is:

[0018]

[0019] Where R is airway resistance, k1 , k 2 are different fitting coefficients respectively, and Patency is the patency of airway.

[0020] One of the preferred solutions, the fitting coefficient k 1 is 178.2, and the fitting coefficient k 2 It is -0.402.

[0021] A computer-readable storage medium, wherein the computer-readable storage medium includes a method program for dynamically estimating airway resistance of a respiratory support device. When the method program for dynamically estimating airway resistance of a respiratory support device is executed by a processor, the steps of the method for dynamically estimating airway resistance of a respiratory support device are implemented.

[0022] A system for dynamically estimating airway resistance of a respiratory support device, comprising a memory and a processor; the memory stores a computer program that can be run on the processor, and the processor implements the method for dynamically estimating airway resistance of a respiratory support device when executing the computer program.

[0023] In the above technical solution of the present invention, the method for dynamically estimating the airway resistance of the respiratory support device includes the following steps: obtaining the tidal volume, flow change value and pressure difference between exhalation and inspiration of the respiratory support device; constructing an airway patency evaluation model based on the inspiratory tidal volume per unit inspiratory time, the flow change value per unit expiratory time and the pressure difference between unit inspiratory time and unit expiratory time, and calculating the airway patency according to the airway patency model; fitting the airway patency evaluation model to obtain a fitting model of airway resistance and airway patency, and calculating the airway resistance of the respiratory support device according to the fitting model. The present invention introduces the intermediate variable airway patency, attributes the monitoring parameters of the tidal volume to those related only to the airway resistance, thereby obtaining the airway patency, and then establishes a mathematical model related to air resistance, thereby solving the technical problem of how to accurately and quickly estimate the airway resistance and output the results in the autonomous dual-level mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of a method for dynamically estimating airway resistance of a respiratory support device according to an embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the relationship between airway resistance and airway patency according to an embodiment of the present invention.

[0027] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0030] In addition, in the present invention, the descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0031] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0032] See also Figure 1-Figure 2 According to one aspect of the present invention, the present invention provides a method for dynamically estimating airway resistance of a respiratory support device, wherein the method for dynamically estimating airway resistance of a respiratory support device comprises the following steps:

[0033] S1. Obtain the tidal volume, flow change value, and pressure difference between exhalation and inspiration of the respiratory support equipment;

[0034] S2. constructing an airway patency assessment model based on the inspiratory tidal volume per unit inspiratory time, the flow rate change value per unit expiratory time, and the pressure difference between the unit inspiratory time and the unit expiratory time, and calculating the airway patency according to the airway patency model;

[0035] S3. Fitting the airway patency assessment model to obtain a fitting model of airway resistance and airway patency, and calculating the airway resistance of the respiratory support device according to the fitting model.

[0036] Specifically, in the present embodiment, an important monitored quantity affected by airway resistance during each breath of the human body is tidal volume. Based on this, parameters related to tidal volume are further analyzed. Factors that affect the tidal volume each time the patient inhales or exhales also include: inspiratory effort, pressure difference of respiratory support equipment, and compliance; wherein, inspiratory effort can be replaced by inspiratory time, which is proportional to the tidal volume, the difference between inspiratory pressure and expiratory pressure is proportional to the tidal volume, and compliance is replaced by the rate of flow change during exhalation; thereby introducing an intermediate variable, airway patency, which is inversely proportional to airway resistance. The greater the airway patency, the smaller the airway resistance. In the present invention, the tidal volume per unit inspiratory time and unit pressure difference, and the ability to recover flow during exhalation are used to evaluate airway patency.

[0037] Specifically, in this embodiment, the inspiratory tidal volume is the inspiratory tidal volume per unit inspiratory time of the respiratory support device.

[0038] Specifically, in this embodiment, the flow change value is a flow change value within a unit exhalation time during the exhalation phase, and the flow change value is strongly negatively correlated with the compliance of the respiratory support device.

[0039] Specifically, in this embodiment, the pressure difference is:

[0040] ΔP=P 1 -P 2

[0041] Where ΔP is the pressure difference between unit inspiration time and unit expiration time, P 1 is the maximum pressure reached during inspiration, P 2 It is the minimum pressure during exhalation.

[0042] Specifically, in this embodiment, the gas path patency assessment model is:

[0043]

[0044] Among them, Patency is the patency of the airway, ΔF is the flow change value per unit expiratory time, V is the inspiratory tidal volume, ΔP is the pressure difference between exhalation and inspiration, and t is the inspiratory time.

[0045] Specifically, in this embodiment, the unit exhalation time is 100 ms.

[0046] Specifically, in this embodiment, the airway patency assessment model has better performance when the tidal volume is larger and the flow rate returns to zero faster during the exhalation phase. However, the pressure difference and the inhalation time also affect the tidal volume, that is, the two variables are inversely proportional to the tidal volume. By dividing by the pressure difference and the inhalation time at the same time to eliminate some of the effects, the larger the Patency, the better the airway patency performance, which is inversely proportional to the airway resistance. Therefore, by fitting with the airway resistance of the active simulated lung, an exponential fitting formula greater than 0.97 can be obtained, that is, a fitting model.

[0047] Specifically, in this embodiment, the fitting model is:

[0048]

[0049] Where R is airway resistance, k 1 , k 2 are different fitting coefficients respectively, and Patency is the patency of airway.

[0050] Specifically, in this embodiment, the fitting coefficient k 1 is 178.2, and the fitting coefficient k 2 is -0.402; the present invention does not make any specific limitation, and can be set according to the needs, see Figure 2 , is the above fitting coefficient k 1 , k 2 The relationship between airway resistance and airway patency.

[0051] According to one aspect of the present invention, the present invention provides a computer-readable storage medium, which includes a method program for dynamically estimating the airway resistance of a respiratory support device. When the method program for dynamically estimating the airway resistance of a respiratory support device is executed by a processor, the steps of the method for dynamically estimating the airway resistance of a respiratory support device are implemented.

[0052] According to one aspect of the present invention, the present invention provides a system for dynamically estimating airway resistance of a respiratory support device, the system comprising a memory and a processor; the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the method for dynamically estimating airway resistance of a respiratory support device as described.

[0053] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for dynamically estimating airway resistance of a respiratory support device, characterized in that: The following steps are involved: S1. Obtain the tidal volume, flow change value, and pressure difference between exhalation and inspiration of the respiratory support equipment; S2. constructing an airway patency assessment model based on the inspiratory tidal volume per unit inspiratory time, the flow rate change value per unit expiratory time, and the pressure difference between the unit inspiratory time and the unit expiratory time, and calculating the airway patency according to the airway patency model; S3. Fitting the airway patency assessment model to obtain a fitting model of airway resistance and airway patency, and calculating the airway resistance of the respiratory support device according to the fitting model.

2. The method for dynamically estimating airway resistance of respiratory support equipment according to claim 1, characterized in that: The inspiratory tidal volume is the inspiratory tidal volume per unit inspiratory time of the respiratory support device.

3. The method for dynamically estimating airway resistance of a respiratory support device according to any one of claims 1 to 2, characterized in that: The flow change value is a flow change value within a unit exhalation time during the exhalation phase, and the flow change value is strongly negatively correlated with the compliance of the respiratory support device.

4. The method for dynamically estimating airway resistance of a respiratory support device according to any one of claims 1 to 2, characterized in that: The pressure difference is: ΔP=P1-P2 Wherein, ΔP is the pressure difference between unit inhalation time and unit exhalation time, P1 is the maximum pressure reached during inhalation, and P2 is the minimum pressure during exhalation.

5. The method for dynamically estimating airway resistance of a respiratory support device according to any one of claims 1 to 2, characterized in that: The airway patency assessment model is: Among them, Patency is the patency of the airway, ΔF is the flow change value per unit expiratory time, V is the inspiratory tidal volume, ΔP is the pressure difference between exhalation and inspiration, and t is the inspiratory time.

6. The method for dynamically estimating airway resistance of respiratory support equipment according to claim 5, characterized in that: The unit exhalation time is 100 ms.

7. The method for dynamically estimating airway resistance of a respiratory support device according to any one of claims 1 to 2, characterized in that: The fitting model is: Among them, R is airway resistance, k1 and k2 are different fitting coefficients, and Patency is airway patency.

8. The method for dynamically estimating airway resistance of respiratory support equipment according to claim 7, characterized in that: The fitting coefficient k1 is 178.2, and the fitting coefficient k2 is -0.

402.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a method program for dynamically estimating airway resistance of a respiratory support device. When the method program for dynamically estimating airway resistance of a respiratory support device is executed by a processor, the steps of the method for dynamically estimating airway resistance of a respiratory support device as described in any one of claims 1-8 are implemented.

10. A dynamic estimation system of airway resistance of a respiratory support device, characterized in that: The respiratory support equipment airway resistance dynamic estimation system includes a memory and a processor; the memory stores a computer program that can be run on the processor, and when the processor executes the computer program, it implements the respiratory support equipment airway resistance dynamic estimation method as described in any one of claims 1-8.

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