CN115970109B - Respiratory ventilation prediction preprocessing method, ventilator, controller and storage medium - Google Patents

Abstract

The invention discloses a breathing ventilation prediction preprocessing method, a breathing machine, a controller and a storage medium, wherein the method comprises the following steps: dividing the respiratory phase, wherein the flow average value is greater than +e1 and divided into an inhalation phase, the flow average value is less than-e 1 and divided into an exhalation phase, and the respiratory phase is in the interval of [ -e1, +e1] and divided into a holding phase; the respiratory state prediction result comprises the predicted expiration of the end inspiration, the predicted secondary inspiration and the predicted secondary expiration of the end expiration; preprocessing is performed for different predicted respiratory states. According to the scheme, different refined breathing pretreatment can be carried out according to different breathing states accurately predicted, so that the comfort of a patient is improved, the breathing difficulty caused by breathing false triggering caused by unstable control and slow switching of breathing control lag at the end of expiration and breathing difficulty caused by untimely pressure release at the end of inspiration can be effectively reduced, and the breathing difficulty during secondary inspiration is relieved.

Description

Respiratory ventilation prediction preprocessing method, ventilator, controller and storage medium

Technical Field

The invention relates to the technical field of respiratory measurement, prediction and control, in particular to a respiratory ventilation prediction preprocessing method, a ventilator, a controller and a storage medium.

Background

Respiratory phase control is an important performance of a breathing machine, and it is common practice to obtain respiratory characteristic information related to a patient by detecting airflow changes of the breath, and control the breathing machine to breathe spontaneously by the patient according to the respiratory characteristic information, so that the patient feels smooth and comfortable in breathing. Generally, the respiratory phase includes an respiratory phase and an inspiratory phase, the respiratory phase (expiration phase) is a phase of the ventilator set for completing an expiration process, and the inspiratory phase (inspiratory phase) is a phase of the ventilator set for completing an inspiration process. The relationship between flow and respiratory cycle of respiratory phase is schematically shown in fig. 1.

The respiration control in the prior scheme adopts a preset threshold value that the flow value exceeds the flow reference value, so that the inhalation and exhalation state is judged, and the single-point switching is performed, and the control mode has control hysteresis, so that the inhalation is difficult in the initial stage of inhalation, the exhalation is difficult in the initial stage of exhalation, and the inhalation is easy to shake in the final stage of exhalation to trigger inhalation by mistake. If some conditions of secondary inspiration and secondary expiration exist, the control strategy cannot be quickly adaptively adjusted. The secondary inhalation refers to the case of inhaling again after a short stay after the inhalation is completed; the secondary expiration refers to the condition that the expiration is performed again after the expiration is stopped briefly after the expiration is finished, the period of the secondary inspiration and the secondary expiration is short, the occurrence is abrupt, and the existing scheme cannot solve the problem well.

As shown in fig. 2, is a graph of the flow rate change as the patient breathes. In fact, the breathing waveforms of different people are inconsistent, after the inspiration is finished or the expiration is finished, a certain pause time is often generated, in the prior art, the pause time, namely, the area between +e1 and-e 1, is divided into inspiration or expiration control, a certain false triggering and control hysteresis problem is caused, the false triggering and control hysteresis shown in a solid line circle and a dotted line circle in fig. 3 is generated, and in fact, the false triggering and control hysteresis is shown to be more serious than that in an image, and in this case, the user experience is poor.

Therefore, it is an object of the present invention to develop a method and a technique for effectively reducing the inhalation false triggering caused by unstable control at the end of exhalation, the inhalation difficulty caused by slow switching of inhalation control lag, the exhalation difficulty caused by untimely pressure release at the end of inhalation, and the inhalation difficulty at the time of secondary inhalation.

Disclosure of Invention

The invention aims to provide a breathing ventilation prediction preprocessing method, a breathing machine, a controller and a storage medium.

To achieve the above object, a first aspect of the present invention provides a respiratory ventilation prediction preprocessing method, which includes:

in the respiratory phase control of a breathing machine, an upper threshold +e1 and a lower threshold-e 1 are set for the flow average value of the breathing machine; having normal breathing control parameters for breathing control in the breathing phase control;

dividing respiratory phases, wherein the flow average value is greater than +e1 and divided into respiratory phases, the flow average value is smaller than-e 1 and divided into respiratory phases, and the flow average value is within the interval [ -e1, +e1] and divided into holding phases;

sampling the flow at a sampling frequency t; calculating flow slopes of two adjacent flow sampling points;

calculating the flow in the inspiration phase period to obtain the inspiration tidal volume; calculating the flow in the expiration phase period to obtain expiration tidal volume;

after entering a hold phase, carrying out breathing state prediction according to flow slope and tidal volume data in continuous sampling; the respiratory state prediction result comprises the predicted expiration of the end inspiration, the predicted secondary inspiration and the predicted secondary expiration of the end expiration;

for the different respiratory states predicted, the following pre-treatments were performed:

pretreatment of inspiration end:

if the expiration is predicted: the method comprises the steps of adjusting a normal respiratory control parameter to be a first respiratory control parameter different from the normal respiratory control parameter, enabling the first respiratory control parameter to be effective when exiting a holding phase and entering an expiratory phase, stopping the effective time of the first respiratory control parameter after a period of time, and recovering the first respiratory control parameter to the original normal respiratory control parameter;

if secondary inspiration is predicted: the normal breathing control parameters are adjusted to second breathing control parameters different from the normal breathing control parameters, the second breathing control parameters are effective when exiting the holding phase and entering the inhalation phase, and the second breathing control parameters are stopped in effective time after a period of time, so that the original normal breathing control parameters are recovered;

pretreatment of end expiration:

if the inspiration is predicted: the normal breathing control parameters are adjusted to third breathing control parameters different from the normal breathing control parameters, the third breathing control parameters are effective when exiting the holding phase and entering the inhaling phase, and the third breathing control parameters are stopped in effective time after a period of time, and the original normal breathing control parameters are recovered;

if secondary exhalation is predicted: and adjusting the normal respiratory control parameter to a fourth respiratory control parameter different from the normal respiratory control parameter, wherein the fourth respiratory control parameter is effective when exiting the hold phase and entering the breathing phase, and the fourth respiratory control parameter is stopped in the effective time after a period of time, so that the original normal respiratory control parameter is recovered.

The second aspect of the invention provides a breathing machine, which is provided with a gas circuit module, a detection module and a controller; wherein, the liquid crystal display device comprises a liquid crystal display device,

a gas circuit module configured to generate a flow of breathable gas for breathing, the flow of breathable gas employing respiratory phase control to adjust normal respiratory control parameters;

a detection module configured at least for flow sampling at a sampling frequency t;

a controller configured to perform respiratory phase control using the normal respiratory control parameter, the first respiratory control parameter, the second respiratory control parameter, the third respiratory control parameter, or the fourth respiratory control parameter to vary the flow of breathable gas in the gas circuit module.

A third aspect of the invention proposes a controller comprising a storage medium, a processor and a control program stored on the storage medium and executable on the processor, the processor implementing the steps of the method according to the first aspect when executing the control program.

A fourth aspect of the present invention proposes a storage medium having stored thereon a control program which, when executed by a processor, causes the processor to perform the steps of the method according to the first aspect.

The content of the present invention is explained as follows:

1. by implementing the technical scheme of the invention, aiming at the problems of inhalation false triggering caused by unstable control at the end of the existing exhalation, inhalation difficulty caused by slow switching of inhalation control lag, exhalation difficulty caused by untimely pressure release at the end of the inhalation and inhalation difficulty in relieving secondary inhalation, a third state except for an inhalation phase and an exhalation phase is particularly proposed on the respiratory phase division of respiratory phase control, a respiratory control mode is added by using the respiratory phase division mode, and the core is respiratory prediction and pretreatment of the maintenance phase; when respiration prediction is carried out, the respiration state is predicted by using flow slope and tidal volume data in continuous sampling, and a plurality of K values in continuous sampling are adopted for joint judgment, and when the continuous flow slopes are all larger or smaller than relevant values, the respiration state is predicted, so that judgment errors are reduced; meanwhile, because the air flow jitter possibly exists in-e1 to +e1, even if a plurality of continuous flow slopes are in one interval, the possibility of prediction breathing errors still exists, so that a mode of combining tidal volume and flow slope judgment is introduced to further avoid judgment errors; when the breathing pretreatment control is carried out, different refined breathing pretreatment is carried out according to different breathing states accurately predicted, and the breathing control can be effectively, timely and accurately carried out, so that the comfort of a patient is improved, the breathing difficulty caused by the false triggering of inspiration caused by unstable control at the end of expiration, the slow switching of inspiration control lag and the breathing difficulty caused by untimely pressure release at the end of inspiration can be effectively reduced, and the breathing difficulty in the secondary inspiration is relieved.

2. In the first aspect of the above-described technical solution, the flow slope k= (current sampling point flow-previous sampling point flow)/sampling frequency;

a slope threshold K1 and a slope threshold K2 at the end of inspiration, a slope threshold K3 and a slope threshold K4 at the end of expiration and an expected tidal volume TV are set in the breathing machine;

the respiratory state prediction and pretreatment are performed based on the gradient threshold K1 at the end of inspiration, the gradient threshold K2, the gradient threshold K3 at the end of expiration, the gradient threshold K4, the flow gradient K, and the predicted tidal volume TV, the inspiratory tidal volume TV1, and the expiratory tidal volume TV2.

3. In a first aspect of the foregoing aspect, in the step of predicting the respiratory state based on the flow slope and the tidal volume data in consecutive samples, the method includes the following determination and prediction:

end of inspiration:

if K is less than K1 and TV1> N1 is TV, then expiration is predicted;

if K is greater than K2 and TV1< N1. TV, then predicting a secondary inhalation;

end-tidal:

if K is greater than K3 and TV2> N2. TV1, then air suction is predicted;

if K is less than K4 and TV2< N2 is TV1, then secondary exhalation is predicted;

where N1 is the percentage of the user's tidal volume under normal breathing and the predicted tidal volume, and N2 is the percentage of the user's tidal volume under normal breathing and the predicted tidal volume corrected for error.

4. In a first aspect of the foregoing disclosure, the respiratory phase control of the ventilator is in the form of control PWM (pulse width modulation), PWM1 = PWM2+ (F1-Fave) a;

wherein PWM1 is the PWM value actually issued, PWM2 is the PWM value of the output pressure under the standard connection, F1 is the real-time flow value, fave is the average flow in a period of time T, and a is the normal respiration control coefficient.

5. In the first aspect of the above technical solution, during the control of the end of inspiration:

the parameter adjustment method for predicting the expiration is to adjust the normal respiration control coefficient a to be a first respiration control coefficient A1, wherein a1=a (TV 1/(N1×tv)); when the first respiratory control coefficient A1 of the expiration lasts for a period of time until the expiratory tidal volume TV2 is more than 50% TV1, the effective time of the first respiratory control coefficient A1 stops and the normal respiratory control coefficient a is recovered;

the parameter adjustment mode for predicting the secondary inhalation is that the normal respiration control coefficient a is adjusted to be a second respiration control coefficient A2, wherein A2=a (N1. Times. TV-TV 1)/(N1. Times. TV), when the second respiration control coefficient A2 of the secondary inhalation lasts for a period of time until the secondary inhalation tidal volume TV3 is more than 50% (TV-TV 1), the effective time of the second respiration control coefficient A2 is stopped, and the normal respiration control coefficient a is recovered; secondary inspiratory tidal volume TV3 is equivalent to inspiratory tidal volume TV1;

during end-tidal control:

the parameter adjustment mode of the predicted inhalation is that the normal respiration control coefficient a is adjusted to be a third respiration control coefficient A3, wherein A3=a (1+ (TV-TV 1)/TV); when the third respiratory control coefficient A3 of inspiration lasts for a period of time until the inspiration tidal volume TV1 is more than 50% TV, the effective time of the third respiratory control coefficient A3 stops and the normal respiratory control coefficient a is restored;

the parameter adjustment mode for predicting the secondary exhalation is to adjust the normal respiratory control coefficient a to a fourth respiratory control coefficient A4, wherein a4=a (1+ (TV 2-TV 1)/TV 1); when the fourth respiratory control coefficient A4 of the secondary expiration lasts for a period of time until the tidal volume TV4 of the secondary expiration is more than 50 percent (TV 1-TV 2), the effective time of the fourth respiratory control coefficient A4 stops and the normal respiratory control coefficient a is recovered; the secondary expiratory tidal volume TV4 is identical to the expiratory tidal volume TV2.

6. In the first aspect of the foregoing technical solution, the flow of the inspiratory phase is calculated by integration to obtain an inspiratory tidal volume TV1, TV 1= (Fa-Fave) ×t+ (Fb-Fave) ×t+ (Fx-Fave) ×t, where Fa-Fx in the formula refers to each flow sampling value in the period of the inspiratory phase; TV3 = TV1;

integrating the flow of the expiratory phase to obtain an expiratory tidal volume TV2, wherein Tv2= (Fa-Fave) t+ (Fb-Fave) t+ (Fx-Fave) t, and Fa-Fx in the formula refers to each flow sampling value in the period of the expiratory phase; TV4 = TV2.

7. In a second aspect of the above technical solution, the controller is configured to perform the following method steps: the controller is configured to perform the following method steps:

for the different predicted respiratory states, the following preprocessing controls are performed:

pretreatment control of inspiration end:

if the expiration is predicted: the method comprises the steps of adjusting a normal breathing control parameter of a gas circuit module to be a first breathing control parameter different from the normal breathing control parameter, enabling the first breathing control parameter to take effect when exiting a holding phase and entering a breathing phase, stopping the first breathing control parameter for a period of time after the first breathing control parameter takes effect, and recovering the first breathing control parameter to the original normal breathing control parameter;

if secondary inspiration is predicted: the normal breathing control parameters of the air circuit module are adjusted to second breathing control parameters different from the normal breathing control parameters, the second breathing control parameters take effect when exiting the holding phase and entering the inhalation phase, and the second breathing control parameters stop taking effect after a period of time, and the original normal breathing control parameters are recovered;

pretreatment control of inspiration end:

if the inspiration is predicted: the normal breathing control parameters of the air circuit module are adjusted to third breathing control parameters different from the normal breathing control parameters, the third breathing control parameters take effect when exiting the holding phase and entering the inhalation phase, and the third breathing control parameters stop taking effect after a period of time, and the original normal breathing control parameters are recovered;

if secondary exhalation is predicted: and adjusting the normal breathing control parameter of the gas circuit module to a fourth breathing control parameter different from the normal breathing control parameter, wherein the fourth breathing control parameter takes effect when exiting the hold phase and entering the breathing phase, and the fourth breathing control parameter stops taking effect after a period of time, and is restored to the original normal breathing control parameter.

8. In the technical scheme of the invention, thresholds are set up and down on the flow average value, and +e1 and-e 1 are selected by adopting a dynamic threshold method, and the specific method refers to a breathing phase control method of a breathing machine based on the dynamic threshold of a patent CN 114209940A.

9. In the technical scheme of the invention, the normal respiratory control parameters comprise a normal respiratory control coefficient a, and can be related to respiratory airflow pressure, flow, valve opening and closing degree and the like related to respiratory control.

10. In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically linked, may be directly linked, may be indirectly linked through an intervening medium, and may be in communication between two elements or in an interactive relationship therebetween, unless expressly defined otherwise. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

11. In the present invention, the terms "center," "upper," "lower," "axial," "bottom," "inner," "outer," and the like refer to an azimuth or positional relationship based on the azimuth or positional assembly relationship shown in the drawings, for convenience of description and simplification of the description, and do not indicate or imply that the apparatus or element referred to must have a specific azimuth, be configured and operated in a specific azimuth, and thus should not be construed as limiting the present application.

12. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

Due to the application of the scheme, compared with the prior art, the invention has the following advantages and effects:

aiming at the problems of false triggering of inspiration caused by unstable control at the end of expiration, difficult inspiration caused by slow switching of inspiration control lag, difficult expiration caused by untimely pressure release at the end of inspiration and difficult inspiration when the inspiration is released, the invention particularly provides a third state except for an inspiration phase and an expiration phase on the respiratory phase division of respiratory phase control, and increases the respiratory control mode by using the respiratory phase division mode, wherein the core is respiratory prediction and pretreatment of the maintenance phase; when respiration prediction is carried out, the respiration state is predicted by using flow slope and tidal volume data in continuous sampling, and a plurality of K values in continuous sampling are adopted for joint judgment, and when the continuous flow slopes are all larger or smaller than relevant values, the respiration state is predicted, so that judgment errors are reduced; meanwhile, because the air flow jitter possibly exists in-e1 to +e1, even if a plurality of continuous flow slopes are in one interval, the possibility of prediction breathing errors still exists, so that a mode of combining tidal volume and flow slope judgment is introduced to further avoid judgment errors; when the breathing pretreatment control is carried out, different refined breathing pretreatment is carried out according to different breathing states accurately predicted, and the breathing control can be effectively, timely and accurately carried out, so that the comfort of a patient is improved, the breathing difficulty caused by the false triggering of inspiration caused by unstable control at the end of expiration, the slow switching of inspiration control lag and the breathing difficulty caused by untimely pressure release at the end of inspiration can be effectively reduced, and the breathing difficulty in the secondary inspiration is relieved.

Drawings

FIG. 1 is a schematic diagram of the relationship between flow and respiratory cycle of respiratory phase in prior art;

FIG. 2 is a graph of flow rate change as a patient breathes;

FIG. 3 is a schematic waveform diagram of a false trigger and control lag in breathing of a patient in accordance with prior art arrangements;

FIG. 4 is a schematic diagram of respiratory phase division according to an embodiment of the present invention;

FIG. 5 is a graph of breathing waveforms (one) before and after intervention in accordance with aspects of the present invention;

fig. 6 shows a breathing waveform (two) before and after intervention in the solution of the present invention.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is, however, susceptible of embodiment in many other forms than those described herein and similar modifications can be made by those skilled in the art without departing from the spirit of the application, and therefore the application is not to be limited to the specific embodiments disclosed below.

Example 1

In a first embodiment of the present invention, a respiratory ventilation prediction preprocessing method for a ventilator is provided, the method including:

in the respiratory phase control of a breathing machine, an upper threshold +e1 and a lower threshold-e 1 are set for the flow average value of the breathing machine; having normal breathing control parameters for breathing control in the breathing phase control;

dividing respiratory phases, wherein the flow average value is greater than +e1 and divided into respiratory phases, the flow average value is smaller than-e 1 and divided into respiratory phases, and the flow average value is within the interval [ -e1, +e1] and divided into holding phases;

sampling the flow at a sampling frequency t; calculating the flow slope K of two adjacent flow sampling points, wherein the flow slope K= (current sampling point flow-previous sampling point flow)/sampling frequency;

calculating the flow in the inspiration phase period to obtain the inspiration tidal volume; calculating the flow in the expiration phase period to obtain expiration tidal volume;

after entering a hold phase, carrying out breathing state prediction according to flow slope and tidal volume data in continuous sampling; the respiratory state prediction result comprises the predicted expiration of the end inspiration, the predicted secondary inspiration and the predicted secondary expiration of the end expiration;

for the different respiratory states predicted, the following pre-treatments were performed:

pretreatment of inspiration end:

if the expiration is predicted: the method comprises the steps of adjusting a normal respiratory control parameter to be a first respiratory control parameter different from the normal respiratory control parameter, enabling the first respiratory control parameter to be effective when exiting a holding phase and entering an expiratory phase, stopping the effective time of the first respiratory control parameter after a period of time, and recovering the first respiratory control parameter to the original normal respiratory control parameter;

if secondary inspiration is predicted: the normal breathing control parameters are adjusted to second breathing control parameters different from the normal breathing control parameters, the second breathing control parameters are effective when exiting the holding phase and entering the inhalation phase, and the second breathing control parameters are stopped in effective time after a period of time, so that the original normal breathing control parameters are recovered;

pretreatment of end expiration:

if the inspiration is predicted: the normal breathing control parameters are adjusted to third breathing control parameters different from the normal breathing control parameters, the third breathing control parameters are effective when exiting the holding phase and entering the inhaling phase, and the third breathing control parameters are stopped in effective time after a period of time, and the original normal breathing control parameters are recovered;

if secondary exhalation is predicted: and adjusting the normal respiratory control parameter to a fourth respiratory control parameter different from the normal respiratory control parameter, wherein the fourth respiratory control parameter is effective when exiting the hold phase and entering the breathing phase, and the fourth respiratory control parameter is stopped in the effective time after a period of time, so that the original normal respiratory control parameter is recovered.

In an embodiment of the present invention, the respiratory phase control of the ventilator is in the form of controlling PWM, PWM1 = PWM2+ (F1-wave) a;

wherein PWM1 is the PWM value actually issued, PWM2 is the PWM value of the output pressure under the standard connection, F1 is the real-time flow value, fave is the average flow in a period of time T, and a is the normal respiration control coefficient.

In the first embodiment, the ventilator is set with the gradient threshold K1 at the end of inspiration, the gradient threshold K2, the gradient threshold K3 at the end of expiration, the gradient threshold K4, and the estimated tidal volume TV; the respiratory state prediction and pretreatment are performed based on the gradient threshold K1 at the end of inspiration, the gradient threshold K2, the gradient threshold K3 at the end of expiration, the gradient threshold K4, the flow gradient K, and the predicted tidal volume TV, the inspiratory tidal volume TV1, and the expiratory tidal volume TV2.

In the first embodiment, after entering the hold phase, the respiratory state prediction is performed according to the flow slope and the tidal volume data in the continuous sampling; the respiratory state prediction result includes a predicted expiration of the end of inspiration, a predicted secondary inspiration, and a predicted inspiration and a predicted secondary expiration of the end of expiration. The step of breath prediction comprises the following judgment and prediction:

end of inspiration:

if K is less than K1 and TV1> N1 is TV, then expiration is predicted;

if K is greater than K2 and TV1< N1. TV, then predicting a secondary inhalation;

end-tidal:

if K is greater than K3 and TV2> N2. TV1, then air suction is predicted;

if K is less than K4 and TV2< N2 is TV1, then secondary exhalation is predicted;

where N1 is the percentage of the user's tidal volume under normal breathing and the predicted tidal volume, and N2 is the percentage of the user's tidal volume under normal breathing and the predicted tidal volume corrected for error.

In the first embodiment, in the control process of the inhalation end:

the parameter adjustment method for predicting the expiration is to adjust the normal respiration control coefficient a to be a first respiration control coefficient A1, wherein a1=a (TV 1/(N1×tv)); when the first respiratory control coefficient A1 of the expiration lasts for a period of time until the expiratory tidal volume TV2 is more than 50% TV1, the effective time of the first respiratory control coefficient A1 stops and the normal respiratory control coefficient a is recovered;

the parameter adjustment mode for predicting the secondary inhalation is that the normal respiration control coefficient a is adjusted to be a second respiration control coefficient A2, wherein A2=a (N1. Times. TV-TV 1)/(N1. Times. TV), when the second respiration control coefficient A2 of the secondary inhalation lasts for a period of time until the secondary inhalation tidal volume TV3 is more than 50% (TV-TV 1), the effective time of the second respiration control coefficient A2 is stopped, and the normal respiration control coefficient a is recovered; secondary inspiratory tidal volume TV3 is equivalent to inspiratory tidal volume TV1;

during end-tidal control:

the parameter adjustment mode of the predicted inhalation is that the normal respiration control coefficient a is adjusted to be a third respiration control coefficient A3, wherein A3=a (1+ (TV-TV 1)/TV); when the third respiratory control coefficient A3 of inspiration lasts for a period of time until the inspiration tidal volume TV1 is more than 50% TV, the effective time of the third respiratory control coefficient A3 stops and the normal respiratory control coefficient a is restored;

the parameter adjustment mode for predicting the secondary exhalation is to adjust the normal respiratory control coefficient a to a fourth respiratory control coefficient A4, wherein a4=a (1+ (TV 2-TV 1)/TV 1); when the fourth respiratory control coefficient A4 of the secondary expiration lasts for a period of time until the tidal volume TV4 of the secondary expiration is more than 50 percent (TV 1-TV 2), the effective time of the fourth respiratory control coefficient A4 stops and the normal respiratory control coefficient a is recovered; the secondary expiratory tidal volume TV4 is identical to the expiratory tidal volume TV2.

The following description will take one of the preferred embodiments as an example.

In the preferred embodiment of the present invention, a respiratory phase dividing method in a respiratory process is provided, a third state other than an inhalation phase and an exhalation phase is provided, a hold phase is provided, a respiratory control method is added by using the respiratory phase dividing method, and the core is respiratory state prediction and preprocessing of the hold phase.

The interval division mode is as follows:

the upper threshold +e1 and the lower threshold-e 1 on the flow average value, and the upper threshold +e1 and the lower threshold-e 1 can be selected by adopting a dynamic threshold method, and the specific method can refer to a breathing phase control method of the breathing machine based on the dynamic threshold of the published patent CN 114209940A.

Referring to fig. 4, respiratory phase interval division: the flow rate F of the inhalation phase is greater than +e1, the flow rate F of the hold phase is at [ -e1, +e1], the flow rate F of the exhalation phase is less than-e 1, the original inhalation exhalation control mode is that the PWM1 = PWM2+ (F1-Fave) a is kept unchanged, and the added hold phase is described.

Maintaining the phase entry condition with the flow in the [ -e1, +e1] interval. Within the hold phase, a prediction of respiratory state is made, with the predicted subsequent breaths at this stage being present: expiration of end-of-inspiration expiration, secondary inspiration, ventilator state corresponding respectively: the pressure is required to be released in advance and increased; and end-tidal inspiration and secondary expiration.

The suction state prediction method comprises the following steps: the flow sampling frequency is tentatively set to be 2ms once, i.e. t=2ms, and after entering the hold phase, the respiration prediction is performed by adopting a combination of flow slope and tidal volume.

Recording sampling values, calculating slope K= (Fa-Fb)/t by collecting flow Fa and Fb of two adjacent flow sampling points, considering that the exhalation is about to happen when the slope K is smaller than the end-inspiration threshold K1 or smaller than the end-expiration threshold K4, considering that the inhalation is about to happen when the slope K is larger than the end-inspiration threshold K2 or larger than the end-expiration threshold K3, adopting calculated continuous multiple K values in continuous sampling to jointly judge in order to reduce K judgment errors, for example, KA, KB and KC are three continuous slopes calculated by continuous sampling, and predicting the exhalation when the slopes K, KB and KC are smaller than the end-inspiration threshold K1, wherein the thresholds K1, K2, K3 and K4 are test experience values.

However, since there may be a flow jitter in-e 1 to +e1, even if a plurality of K are continuously in one of the intervals, there is still a possibility of a predicted respiratory error, so that the tidal volume is introduced and the flow slope is combined to determine, so that the flow of the inspiratory phase and the expiratory phase are integrated to calculate the tidal volumes TV1 and TV2 in the inspiratory phase and the expiratory phase, the calculated inspiratory tidal volume TV1 and expiratory tidal volume TV2 are compared with N1 of the predicted tidal volume TV, the respiratory state is predicted, and the end expiratory tidal volume TV2 is compared with N2 (percentage) of TV1 to predict the respiratory state.

N1 is tentatively set to be 85%, and the percentage of the tidal volume of different people under normal respiration to the predicted tidal volume (weight (8-10 ml/kg)) is measured according to a large amount of experimental data by the value of N1;

n2 is tentatively 90%, theoretically TV1 = TV2, but in practice 5% error is reserved due to sampling errors, respiratory dead space etc.

Inspiratory tidal volume TV1, inspiratory flow integral calculation: TV 1= (Fa-Fave) 2ms+ (Fb-Fave) 2ms+ (Fx-Fave) 2ms;

the secondary inspiration tidal volume TV3 is calculated in the same manner as TV1, TV 3= (Fa-Fave) 2ms+ (Fb-Fave) 2ms+ (Fx-Fave) 2ms;

expiratory tidal volume TV2, expiratory flow integral calculation: TV 2= (Fa-Fave) 2ms+ (Fb-Fave) 2ms+ (Fx-Fave) 2ms;

the secondary expiratory tidal volume TV4 is calculated in the same manner as TV2, TV 4= (Fa-Fave) 2ms+ (Fb-Fave) 2ms+ (Fx-Fave) 2ms;

Fa-Fx refers to the flow of each sample in inspiration or expiration.

The method for calculating the expected tidal volume is as follows: increasing weight input function on a respirator, wherein tv= (8-10 ml/kg of weight G), and temporarily taking tv=9 ml/kg of weight G;

respiratory state prediction:

end of inspiration:

if K is less than K1 and TV1> N1 is TV, then expiration is predicted;

if K is greater than K2 and TV1< N1. TV, then predicting a secondary inhalation;

end-tidal:

if K is greater than K3 and TV2> N2. TV1, then air suction is predicted;

if K is less than K4 and TV2< N2 TV1, then a secondary exhalation is predicted.

For different predicted respiratory states, different pre-treatments are provided:

the corresponding control process of the inspiration end comprises the following steps:

predicting expiration: changing the normal respiratory control coefficient a, recording the changed coefficient as a first respiratory control coefficient A1, enabling the A1 to take effect when exiting the hold phase and entering the expiratory phase, and continuing for a period of time, stopping the A1 effective time when the expiratory tidal volume TV2 is more than 50% TV1, and recovering the coefficient to the original a;

the coefficient changing method comprises the following steps: a1 =a (TV 1/(N1×tv)).

Predicting secondary inspiration: changing the normal respiratory control coefficient a, marking the changed coefficient as a second respiratory control coefficient A2, enabling the A2 to take effect when exiting the holding phase and entering the inhalation phase for a period of time, stopping the A2 effect time when TV3 (TV-TV 1) of the secondary inhalation is more than 50%, and recovering the coefficient to be the original a;

the coefficient changing method comprises the following steps: a2 =a (N1 TV-TV 1)/(N1 TV);

TV3 is calculated in the same manner as TV1, TV 3= (Fa-Fave) 2ms+ (Fb-Fave) 2ms+ (Fx-Fave) 2ms.

The corresponding control process of end expiration:

predicting inspiration:

changing the normal respiration control coefficient a, marking the changed coefficient as a third respiration control coefficient A3, enabling the A3 to take effect when exiting the holding phase and entering the inhalation phase for a period of time, stopping the A3 effective time when the inhalation TV1 is more than 50% TV, and recovering the coefficient to the original a;

the coefficient changing method comprises the following steps: a3 =a (1+ (TV-TV 1)/TV).

Predicting secondary exhalations: changing the normal respiratory control coefficient a, recording the changed coefficient as a fourth respiratory control coefficient A4, enabling the A4 to be effective when exiting the hold phase and entering the expiratory phase, and lasting for a period of time, stopping the A4 effective time when the TV4 of the secondary expiratory phase is more than 50% (TV 1-TV 2), and recovering the coefficient to be the original a.

The coefficient changing method comprises the following steps: a4 =a (1+ (TV 2-TV 1)/TV 1);

TV4 was calculated in the same manner as TV2, TV 4= (Fa-Fave) 2ms+ (Fb-Fave) 2ms+ (Fx-Fave) 2ms.

In the above preferred embodiment, the other cases not in the predicted result are controlled by the original coefficient a.

Example two

The second embodiment of the invention discloses a breathing machine for implementing the breathing ventilation prediction pretreatment method according to the first embodiment of the invention, wherein the breathing machine is provided with a gas path module, a detection module and a controller; wherein, the liquid crystal display device comprises a liquid crystal display device,

a gas circuit module configured to generate a flow of breathable gas for breathing, the flow of breathable gas employing respiratory phase control to adjust normal respiratory control parameters;

a detection module configured at least for flow sampling at a sampling frequency t;

a controller configured to perform respiratory phase control using the normal respiratory control parameter, the first respiratory control parameter, the second respiratory control parameter, the third respiratory control parameter, or the fourth respiratory control parameter to vary the flow of breathable gas in the gas circuit module.

In a second embodiment of the present invention, the controller is configured to perform the following method steps:

for the different predicted respiratory states, the following preprocessing controls are performed:

pretreatment control of inspiration end:

if the expiration is predicted: the method comprises the steps of adjusting a normal breathing control parameter of a gas circuit module to be a first breathing control parameter different from the normal breathing control parameter, enabling the first breathing control parameter to take effect when exiting a holding phase and entering a breathing phase, stopping the first breathing control parameter for a period of time after the first breathing control parameter takes effect, and recovering the first breathing control parameter to the original normal breathing control parameter;

if secondary inspiration is predicted: the normal breathing control parameters of the air circuit module are adjusted to second breathing control parameters different from the normal breathing control parameters, the second breathing control parameters take effect when exiting the holding phase and entering the inhalation phase, and the second breathing control parameters stop taking effect after a period of time, and the original normal breathing control parameters are recovered;

pretreatment control of inspiration end:

if the inspiration is predicted: the normal breathing control parameters of the air circuit module are adjusted to third breathing control parameters different from the normal breathing control parameters, the third breathing control parameters take effect when exiting the holding phase and entering the inhalation phase, and the third breathing control parameters stop taking effect after a period of time, and the original normal breathing control parameters are recovered;

if secondary exhalation is predicted: and adjusting the normal breathing control parameter of the gas circuit module to a fourth breathing control parameter different from the normal breathing control parameter, wherein the fourth breathing control parameter takes effect when exiting the hold phase and entering the breathing phase, and the fourth breathing control parameter stops taking effect after a period of time, and is restored to the original normal breathing control parameter.

Example III

The third embodiment of the invention discloses a controller, which comprises a storage medium, a processor and a control program stored on the storage medium and capable of running on the processor, wherein the processor realizes the steps of the method in the first embodiment when executing the control program.

Example IV

The fourth embodiment of the present invention also discloses a control storage medium, where a control program is stored, where the control program when executed by a processor causes the processor to execute the steps of the method described in the first embodiment.

The method is characterized in that the method is used for carrying out experiments in the prior art and the scheme of the invention, and the simulated use is carried out in the same simulated lung, so that the breathing waveform diagrams before intervention and after intervention are obtained, and are respectively shown as the figure 5 and the figure 6, the scheme carries out different refined breathing pretreatment according to different breathing states accurately predicted after the pretreatment intervention, the waveform is obviously changed, the method is closer to the human body rhythm under ideal state, and the control in the holding phase is more accurate and stable, thus the method can effectively control the end-stage inspiration, B is the end-stage inspiration, C is the end-stage inspiration second inspiration, D is the end-expiration second expiration, the line type is the curve of the breathing waveform before intervention, the line type is the curve of the breathing waveform after intervention, the curve of the line type is the breathing waveform curve after intervention, the comparison of the two curves of the figure 5 and the figure 6 can obviously be seen, the different refined breathing pretreatment is carried out according to different breathing states accurately predicted, the waveform is more accurate and stable, the control in the method is carried out on the control in the holding phase, the curve before the breathing, the curve is more accurate and the breathing is controlled, the method is more stable and the control is more convenient, the end-stage inspiration is controlled, the breathing is difficult and the breathing is difficult to be controlled, and the breathing is difficult to be controlled and the breathing is difficult to breathed is difficult to be controlled and the time when the inspiration is difficult to breathed is difficult to be controlled and the inspiration to be controlled.

The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.

Claims (4)

1. A ventilator, characterized in that: the breathing machine is provided with a gas circuit module, a detection module and a controller; wherein, the liquid crystal display device comprises a liquid crystal display device,

a gas circuit module configured to generate a flow of breathable gas for breathing, the flow of breathable gas employing respiratory phase control to adjust normal respiratory control parameters;

a detection module configured at least for flow sampling at a sampling frequency t;

a controller configured to perform respiratory phase control using the normal respiratory control parameter, the first respiratory control parameter, the second respiratory control parameter, the third respiratory control parameter, or the fourth respiratory control parameter to vary the flow of breathable gas in the airway module;

in the respiratory phase control of a breathing machine, an upper threshold +e1 and a lower threshold-e 1 are set for the flow average value of the breathing machine; having normal breathing control parameters for breathing control in the breathing phase control; a slope threshold K1 and a slope threshold K2 at the end of inspiration, a slope threshold K3 and a slope threshold K4 at the end of expiration and an expected tidal volume TV are set in the breathing machine; according to the slope threshold K1 and K2 at the end of inspiration, the slope threshold K3 and K4 at the end of expiration, the flow slope K, and the predicted tidal volume TV, the inspiration tidal volume TV1 and the expiration tidal volume TV2, the respiratory state is predicted and preprocessed;

dividing respiratory phases, wherein the flow average value is greater than +e1 and divided into respiratory phases, the flow average value is smaller than-e 1 and divided into respiratory phases, and the flow average value is within the interval [ -e1, +e1] and divided into holding phases;

sampling the flow at a sampling frequency t; calculating the flow slope K of two adjacent flow sampling points, wherein the flow slope K= (current sampling point flow-previous sampling point flow)/sampling frequency;

calculating the flow in the inspiration phase period to obtain the inspiration tidal volume; calculating the flow in the expiration phase period to obtain expiration tidal volume;

after entering the hold phase, respiratory state prediction is performed according to flow slope and tidal volume data in continuous sampling, including the following judgment and prediction:

end of inspiration:

if K is less than K1 and TV1> N1 is TV, then expiration is predicted;

if K is greater than K2 and TV1< N1. TV, then predicting a secondary inhalation;

end-tidal:

if K is greater than K3 and TV2> N2. TV1, then air suction is predicted;

if K is less than K4 and TV2< N2 is TV1, then secondary exhalation is predicted;

wherein N1 is the percentage of the tidal volume of the user under normal breathing and the predicted tidal volume, and N2 is the percentage of the tidal volume of the user under normal breathing and the predicted tidal volume after correction according to the error;

for the different respiratory states predicted, the following pre-treatments were performed:

pretreatment of inspiration end:

if the expiration is predicted: the method comprises the steps of adjusting a normal respiratory control parameter to be a first respiratory control parameter different from the normal respiratory control parameter, enabling the first respiratory control parameter to be effective when exiting a holding phase and entering an expiratory phase, stopping the effective time of the first respiratory control parameter after a period of time, and recovering the first respiratory control parameter to the original normal respiratory control parameter;

if secondary inspiration is predicted: the normal breathing control parameters are adjusted to second breathing control parameters different from the normal breathing control parameters, the second breathing control parameters are effective when exiting the holding phase and entering the inhalation phase, and the second breathing control parameters are stopped in effective time after a period of time, so that the original normal breathing control parameters are recovered;

pretreatment of end expiration:

if the inspiration is predicted: the normal breathing control parameters are adjusted to third breathing control parameters different from the normal breathing control parameters, the third breathing control parameters are effective when exiting the holding phase and entering the inhaling phase, and the third breathing control parameters are stopped in effective time after a period of time, and the original normal breathing control parameters are recovered;

if secondary exhalation is predicted: and adjusting the normal respiratory control parameter to a fourth respiratory control parameter different from the normal respiratory control parameter, wherein the fourth respiratory control parameter is effective when exiting the hold phase and entering the breathing phase, and the fourth respiratory control parameter is stopped in the effective time after a period of time, so that the original normal respiratory control parameter is recovered.

2. The ventilator according to claim 1, wherein: the breathing phase control of the breathing machine adopts a form of controlling PWM, and PWM1 = PWM2+ (F1-Fave) a;

wherein PWM1 is the PWM value actually issued, PWM2 is the PWM value of the output pressure under the standard connection, F1 is the real-time flow value, fave is the average flow in a period of time T, and a is the normal respiration control coefficient.

3. The ventilator according to claim 2, wherein:

during the control of the end of inspiration:

the parameter adjustment method for predicting the expiration is to adjust the normal respiration control coefficient a to be a first respiration control coefficient A1, wherein a1=a (TV 1/(N1×tv)); when the first respiratory control coefficient A1 of the expiration lasts for a period of time until the expiratory tidal volume TV2 is more than 50% TV1, the effective time of the first respiratory control coefficient A1 stops and the normal respiratory control coefficient a is recovered;

the parameter adjustment mode for predicting the secondary inhalation is that the normal respiration control coefficient a is adjusted to be a second respiration control coefficient A2, wherein A2=a (N1. Times. TV-TV 1)/(N1. Times. TV), when the second respiration control coefficient A2 of the secondary inhalation lasts for a period of time until the secondary inhalation tidal volume TV3 is more than 50% (TV-TV 1), the effective time of the second respiration control coefficient A2 is stopped, and the normal respiration control coefficient a is recovered; secondary inspiratory tidal volume TV3 is equivalent to inspiratory tidal volume TV1;

during end-tidal control:

the parameter adjustment mode of the predicted inhalation is that the normal respiration control coefficient a is adjusted to be a third respiration control coefficient A3, wherein A3=a (1+ (TV-TV 1)/TV); when the third respiratory control coefficient A3 of inspiration lasts for a period of time until the inspiration tidal volume TV1 is more than 50% TV, the effective time of the third respiratory control coefficient A3 stops and the normal respiratory control coefficient a is restored;

the parameter adjustment mode for predicting the secondary exhalation is to adjust the normal respiratory control coefficient a to a fourth respiratory control coefficient A4, wherein a4=a (1+ (TV 2-TV 1)/TV 1); when the fourth respiratory control coefficient A4 of the secondary expiration lasts for a period of time until the tidal volume TV4 of the secondary expiration is more than 50 percent (TV 1-TV 2), the effective time of the fourth respiratory control coefficient A4 stops and the normal respiratory control coefficient a is recovered; the secondary expiratory tidal volume TV4 is identical to the expiratory tidal volume TV2.

4. A ventilator according to claim 3, characterized in that:

integrating the flow of the gas-absorbing phase to obtain gas-absorbing tidal volumes TV1, tv1= (Fa-Fave) t+ (Fb-Fave) t+ (Fx-Fave) t, wherein Fa-Fx in the formula refer to each flow sampling value in the period of the gas-absorbing phase; TV3 = TV1;

integrating the flow of the expiratory phase to obtain an expiratory tidal volume TV2, wherein Tv2= (Fa-Fave) t+ (Fb-Fave) t+ (Fx-Fave) t, and Fa-Fx in the formula refers to each flow sampling value in the period of the expiratory phase; TV4 = TV2.