CN116392685A

CN116392685A - PAV parameter adjusting method and device for breathing machine

Info

Publication number: CN116392685A
Application number: CN202310392987.5A
Authority: CN
Inventors: 刘庆平; 林攀攀; 朱婷婷; 赵帅; 吴群
Original assignee: Jiangsu Yuyue Medical Equipment and Supply Co Ltd; Suzhou Yuyue Medical Technology Co Ltd; Nanjing Yuyue Software Technology Co Ltd
Current assignee: Jiangsu Yuyue Medical Equipment and Supply Co Ltd; Suzhou Yuyue Medical Technology Co Ltd; Nanjing Yuyue Software Technology Co Ltd
Priority date: 2023-04-13
Filing date: 2023-04-13
Publication date: 2023-07-07

Abstract

The application provides a PAV parameter adjustment method and device for a breathing machine, wherein the method is used for determining a plurality of pre-ventilation characteristic parameter sets corresponding to the preset output time of a sine wave flow ventilation waveform and an initial proportion auxiliary ventilation PAV parameter set corresponding to the pre-ventilation characteristic parameter sets based on a preset sine wave flow ventilation waveform. In the case of PAV ventilation with an initial PAV parameter set, ventilation detection information from the flow and sensing module is acquired. The ventilation detection information is detection information when the ventilator ventilates in the PAV mode. The detection information comprises at least one or more of the following: flow, pressure. Based on the ventilation detection information and the preset assisted ventilation information, a preset parameter updating strategy is matched to update the initial PAV parameter set according to the parameter updating strategy. Based on the updated PAV parameter set, generating a PAV control instruction so as to control the corresponding pressure value of the PAV mode of the breathing machine in real time according to the updated PAV parameter set.

Description

PAV parameter adjusting method and device for breathing machine

Technical Field

The application relates to the technical field of medical equipment, in particular to a method and a device for adjusting parameters of proportional assist ventilation (Proportional Assist Ventilation, PAV) of a breathing machine.

Background

A ventilator is a medical device for rescuing and treating acute or chronic respiratory diseases, and its main function is represented by its ventilation mode. The ventilation mode describes the switching logic of pressure, flow, volume over time states and inspiratory-expiratory phases in ventilator ventilation. Among the ventilator's spontaneous ventilation modes are proportional assist ventilation, PAV, mode and pressure support ventilation (Pressure Support Ventilation, PSV) mode.

At present, most of PAV modes need to be realized by knowing respiratory mechanics parameter information such as airway resistance and lung elasticity of a patient, and the PAV modes need to be realized by a user to set (titrate) an auxiliary coefficient before proportional auxiliary ventilation. On the one hand, the accuracy of the breathing mechanics parameter information is not high in the actual use process of the breathing machine; secondly, the setting of the auxiliary coefficient is too dependent on the experience of the user, and too high or too low of the setting of the auxiliary coefficient affects the normal use experience of the patient, so that the PAV mode is unfavorable for practical use.

Disclosure of Invention

The embodiment of the application provides a PAV parameter adjusting method and device for a breathing machine, which are used for solving the problem that the current breathing machine is unfavorable for normal use of a user and influences the use experience of a patient in a PAV mode.

In one aspect, embodiments of the present application provide a method for adjusting a PAV parameter for a ventilator, the method comprising:

determining a plurality of sets of pre-ventilation characteristic parameters and their corresponding initial set of proportional assist ventilation, PAV, parameters corresponding to a preset output time of a sinusoidal flow ventilation waveform based on a predetermined sinusoidal flow ventilation waveform;

acquiring ventilation detection information from a flow and sensing module under the condition of PAV ventilation with the initial PAV parameter set; wherein the ventilation detection information is detection information of the ventilator when ventilating in PAV mode; the detection information at least comprises one or more of the following: flow rate, pressure;

based on the ventilation detection information and preset auxiliary ventilation information, matching a preset parameter updating strategy to update the initial PAV parameter set according to the parameter updating strategy;

generating PAV control instructions based on the updated PAV parameter set so as to control corresponding pressure values of the PAV mode of the breathing machine in real time according to the updated PAV parameter set.

In one implementation of the present application, generating a pre-ventilation trigger signal to cause the ventilator to supply pressurized gas in the sine wave flow ventilation waveform for the preset output time with the pre-ventilation trigger signal; the preset output time at least comprises the time of preset breathing times of the patient to be ventilated;

Determining pre-ventilation detection information of each breath in the preset output time through the flow and sensing module; the pre-ventilation detection information includes at least: flow, pressure, respiration start time and respiration end time;

analyzing the pre-ventilation detection information and determining the pre-ventilation characteristic parameter set corresponding to each breath;

determining a model according to preset initial PAV parameters, and determining undetermined PAV parameter sets corresponding to the pre-ventilation characteristic parameter sets; the pending PAV parameter set at least comprises a capacity auxiliary parameter and a flow auxiliary parameter;

the initial set of PAV parameters is determined based on each of the pending sets of PAV parameters.

In one implementation of the present application, determining the inspiratory pressure data in the pre-ventilation detection information, and determining an inspiratory pressure peak value and an inspiratory terminal pressure value in the inspiratory pressure data; and

determining a positive end-expiratory pressure value and a tidal volume in the pre-ventilation detection information;

determining a set of pending PAV parameters corresponding to each set of pre-ventilation characteristic parameters according to a preset initial PAV parameter determination model, specifically including:

determining the capacity assist parameter according to the inspiratory terminal pressure value, the expiratory terminal positive pressure value and the tidal volume;

And determining the flow auxiliary parameter based on the inspiration pressure peak value, the capacity auxiliary parameter, the positive end expiratory pressure value and flow data and capacity data at the corresponding moment of the inspiration pressure peak value.

In one implementation manner of the present application, the respiration start time is taken as a starting point, the respiration end time is taken as an end point, the flow of the pre-ventilation detection information corresponding to one respiration is integrated, and the maximum air suction capacity value and the minimum air suction capacity value of the one respiration are determined;

determining an initial tidal volume corresponding to the primary breath according to the maximum inspiratory capacity value, the minimum inspiratory capacity value and a first preset formula;

and calculating a moving average value of initial tidal volumes corresponding to each breath in the pre-ventilation detection information, and taking the moving average value as the tidal volume in the pre-ventilation detection information.

In one implementation of the present application, the inverse of the difference between the breath termination time and the breath start time of the historical predetermined number of consecutive breaths and each breath thereof in the ventilation detection information is determined; the predetermined number of histories is a predetermined number of breaths prior to the current breath;

Calculating the product value of the reciprocal of each difference value and a preset unit time length, and taking each product value as the single respiration frequency of each respiration; and taking the moving average value of the single respiratory rate as the respiratory rate value of the current breath;

determining a tidal volume of the current breath based on the flow of ventilation detection information;

determining a corresponding parameter updating strategy according to the breathing frequency value, the tidal volume and the matching result of the auxiliary ventilation information; the auxiliary ventilation information comprises a preset target respiratory rate value and a target tidal volume.

In one implementation of the present application, a plane rectangular coordinate system is established with respiratory rate values as abscissa and respiratory capacity as ordinate;

generating a plurality of grade interval dividing neighborhoods consisting of different grade interval dividing parameters, the target respiratory rate value and the target tidal volume according to the target respiratory rate value, the target tidal volume and a plurality of preset grade interval dividing parameters of the auxiliary ventilation information;

dividing the neighborhood according to each grade interval, and generating a grade interval dividing region in the plane rectangular coordinate system;

Determining a grade interval dividing region matched with the coordinate corresponding to the breathing frequency value and the tidal volume, and determining a preset parameter updating strategy according to the matched grade interval dividing region; the parameter updating strategy comprises parameter adjusting amplitude and parameter adjusting direction in the PAV parameter set.

In one implementation manner of the present application, the updated PAV parameter set is used as an initial PAV parameter set, and PAV ventilation is performed by using the updated initial PAV parameter set, so as to obtain the corresponding ventilation detection information;

determining whether parameters in the initial PAV parameter set are parameters to be updated according to the matching result of the ventilation detection information and the auxiliary ventilation information corresponding to each breath;

if yes, updating parameters in the initial PAV parameter set before each breath starts until the breathing frequency value, the tidal volume and the auxiliary ventilation information matching result corresponding to the ventilation detection information meet preset conditions; the preset condition is that absolute values of differences between the respiratory rate value and the target respiratory rate value and between the tidal volume and the target tidal volume are smaller than preset values.

In one implementation manner of the present application, after the PAV control instruction is generated, determining a pending pressure value and a pending pressure change curve output by the PAV parameter set according to a second preset formula;

limiting and adjusting each pressure value to be determined in the pressure change curve to input each pressure value to be determined after limiting and adjusting into a pressure controller of the breathing machine according to the slope value of the pressure change curve to be determined, the extreme pressure value corresponding to the extreme point of the pressure change curve to be determined and the corresponding limiting amount, and controlling the corresponding pressure value of the PAV mode of the breathing machine in real time; the limiting amount includes a slope value limiting amount and a maximum value limiting amount; the limiting quantity is used for adjusting the numerical value of each pressure value to be determined.

In one implementation manner of the present application, after updating the PAV parameter sets, each PAV parameter set corresponding to a preset breath and a parameter updating direction of each PAV parameter set are determined; the parameter updating direction comprises a positive updating direction and a negative updating direction;

and updating the parameter updating direction of the current breath and updating the PAV parameter set according to the parameter updating direction and the parameter distance variation of each parameter of the PAV parameter set and the corresponding parameter in the auxiliary ventilation information.

In another aspect, an embodiment of the present application further provides a PAV parameter adjustment device for a breathing machine, where the device includes:

a determining module, configured to determine a plurality of pre-ventilation characteristic parameter sets and corresponding initial proportional assist ventilation PAV parameter sets corresponding to preset output times of a sinusoidal flow ventilation waveform based on a predetermined sinusoidal flow ventilation waveform;

the acquisition module is used for acquiring ventilation detection information from the flow and sensing module under the condition of PAV ventilation by the initial PAV parameter set; wherein the ventilation detection information is detection information of the ventilator when ventilating in PAV mode; the detection information at least comprises one or more of the following: flow rate, pressure;

the matching module is used for matching a preset parameter updating strategy based on the ventilation detection information and preset auxiliary ventilation information so as to update the initial PAV parameter set according to the parameter updating strategy;

and the generating module is used for generating PAV control instructions based on the updated PAV parameter set so as to control the corresponding pressure value of the PAV mode of the breathing machine in real time according to the updated PAV parameter set.

And (3) measuring an initial PAV parameter set by outputting mixed gas with a preset sine wave flow ventilation waveform in a preset output time, then performing PAV ventilation and updating the initial PAV parameter set based on the previous breath so as to control a pressure value corresponding to the PAV mode of the respirator. The initial PAV parameters are measured through the Rong Kong sine wave ventilation, so that auxiliary parameters of the PAV mode can be in an ideal state at first, and the comfort level of each breath of a subsequent patient is ensured. The PAV mode normal use method and device can be used without knowing the difficult respiratory mechanics parameter information such as airway resistance and lung elasticity and without titration initial auxiliary coefficients. In addition, the mechanical ventilation model integrating negative feedback and positive feedback mechanisms is more suitable for users to use, safer and more comfortable.

The method and the device overcome the defect that a user sets the mode auxiliary parameters according to no basis under the existing proportional pressure auxiliary mode PAV. Meanwhile, the application provides an updating strategy for automatically adjusting auxiliary parameters in multiple gears, and on the premise of considering safety and comfort, the breathing freedom degree of a patient is guaranteed, so that the patient can autonomously control the size and rhythm of each breath, and the use experience of the patient is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

FIG. 1 is a schematic diagram of a breathing parameter waveform in a PAV parameter adjustment method for a ventilator according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a ventilator according to a method for adjusting PAV parameters of the ventilator according to an embodiment of the present application;

fig. 3 is a schematic diagram of a dual-limb circuit structure of a ventilator corresponding to a PAV parameter adjusting method for the ventilator in the embodiment of the present application;

FIG. 4 is a schematic flow chart of a PAV parameter adjustment method for a ventilator according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a pre-ventilation characteristic parameter corresponding curve waveform in a PAV parameter adjustment method for a ventilator according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a level interval partitioning region in a PAV parameter adjustment method for a ventilator according to an embodiment of the present application;

FIG. 7 is a schematic flow chart of PAV ventilation in a PAV parameter adjustment method for a ventilator according to an embodiment of the present application;

FIG. 8 is a schematic flow chart of another embodiment of a PAV parameter adjustment method for a ventilator;

fig. 9 is a schematic structural diagram of a PAV parameter adjusting device for a ventilator according to an embodiment of the present application.

Detailed Description

For the purposes, technical solutions and advantages of the present application, the technical solutions of the present application will be clearly and completely described below with reference to specific embodiments of the present application and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

A ventilator is a medical device for rescuing and treating acute or chronic respiratory diseases, and its main function is represented by its ventilation mode. The ventilation mode describes the switching logic of pressure, flow, volume over time states and inspiratory-expiratory phases in ventilator ventilation. Since the advent of ventilators, a number of ventilation modes have emerged, which can be classified into three categories, instruction ventilation CV, assisted ventilation AV, and spontaneous ventilation S, depending on the strength of spontaneous participation of the ventilated patient, and into two categories, pressure support ventilation mode PSV and proportional pressure assisted ventilation mode PAV. PSV is a conventional mode which is common in all commercial ventilators and whose pressure target for the inspiratory phase control of ventilation is a constant set point (except, of course, for a short pressure rise ramp at the beginning of inspiration), i.e. Ptarget (t) =p_set, which is a pressure negative feedback control mode in terms of control principle. Unlike PSV, PAV is a positive feedback control mode (positive amplification of spontaneous respiratory effort), the pressure target of inspiratory phase control of PAV mode is time-varying, the pressure target is proportional to both flow and volume, ptarget (t) =kf×f (t) +kv×v (t). The two autonomous pressure control modes differ mainly in the gas-phase, and the control of the gas-phase is the same. Currently, there is clinical evidence that patient comfort is more advantageous in the PAV mode than in the PSV mode. The reasons why PAV mode is more comfortable than PSV mode are mainly two: first, the freedom of the patient to autonomously control each inhalation in PAV mode is greater, and furthermore, the waveform of the flow of inhalation in PAV mode is more similar to the approximate sine wave shape of natural breathing (see FIG. 1) than the reduced wave shape of inhalation as in PSV mode.

Currently, whatever brand of proportional pressure assist PAV mode has three distinct drawbacks:

(1) The airway resistance and the lung elasticity of the patient are required to be known in each mode, the information of the respiratory mechanics parameters is not guessed by the user, and is not identified on line by a breathing machine, in fact, the information of the credible respiratory mechanics parameters is almost impossible to obtain in autonomous ventilation due to the participation of autonomous effort of the patient, in other cases, the actual respiratory mechanics is very complex, and no linear respiratory mechanics parameters exist for identification;

(2) In each mode, the user is required to set (titrate) the auxiliary coefficient, but no simple method is available for guiding the user to set the key auxiliary coefficient, and if the auxiliary coefficient is set too low, the patient is tired; conversely, if the auxiliary coefficient is set too high, the patient will breathe and depend on the patient, and even the phenomenon of air flow escape (run away) will occur;

(3) In PAV mode, the critical respiratory indexes such as tidal volume, minute ventilation and respiratory rate like the conventional mode cannot be controlled, so in PAV mode, the respiratory index of a patient is in an uncontrolled state, which reflects the difference between the positive feedback mechanism mode and the conventional negative feedback mechanism mode, and the great difference makes the ventilator operators feel ill-suited because they are more familiar with the ventilation mode of the conventional negative feedback mechanism, namely, the ventilation mode with fixed pressure, tidal volume, minute ventilation or respiratory rate as the control target, which is also an important factor that PAV mode cannot realize clinical popularization.

Based on this, the embodiment of the application provides a PAV parameter adjusting method and device for a breathing machine, which are used for solving the problems.

Various embodiments of the present application are described in detail below with reference to the accompanying drawings.

Fig. 2 is a schematic structural diagram of a ventilator according to an embodiment of the present application, and as shown in fig. 2, the ventilator includes an air source 110, an air path structure 120 connected to the air source, and the air path structure 120 is connected to a patient 140 interface through a pipeline 130. And driving and detecting circuit 150, ventilation controller 160, man-machine interaction 170 (man-machine interaction interface), external device 180, power supply unit 190. The external device is an external device connected to the breathing machine, such as an external display screen, and the application is not particularly limited thereto.

The specific structural schematic diagram of the air path structure 120 is shown in fig. 3, and includes: an air filter 1, an oxygen valve 2, an oxygen flow sensor 3, an oxygen mixing chamber 4, an oxygen concentration sensor 5, a turbine 6, an inhalation valve 7, an inhalation flow sensor 8, an inhalation pressure sensor 9, an exhalation flow probe 10, an exhalation pressure sensor 11, an exhalation flow sensor 12, and an exhalation valve 13. The inhalation flow sensor 8 and the exhalation flow probe 10 are respectively connected with a pipeline 130, and the pipeline 130 comprises a bacteria filter 14 in an inhalation pipeline, a bacteria filter 15 in an exhalation pipeline and a humidifier 16 in the inhalation pipeline.

In the actual use process of the breathing machine, air enters the oxygen mixing cavity 4 in the machine after passing through the air filter 1 and is mixed with oxygen from a high-pressure air source, and the high-pressure oxygen enters the oxygen mixing cavity 4 after passing through the oxygen valve 2 and the oxygen flow sensor 3. The oxygen valve 2 can adjust the flow rate of oxygen, and the oxygen flow sensor 3 can monitor the flow rate of oxygen. The mixed gas entering the oxygen mixing cavity 4 is pressurized by the turbine 6 and then enters the front end of the air suction valve 7, the air suction valve 7 adjusts the size of the mixed gas flow and outputs the mixed gas to an air suction pipeline externally connected with the breathing machine after being monitored by the air suction flow sensor 8 and the air suction pressure sensor 9, and the air ventilation pipeline is connected with the bacteria filter 14 and the humidifier 16, so that the effects of cleaning, heating and humidifying can be achieved. An oxygen concentration sensor 5 is also connected in parallel between the output end of the turbine 6 and the air inlet end of the oxygen mixing cavity 4 for monitoring the actual oxygen concentration in the pipeline. The exhaled gas from the patient may enter the machine again via the exhalation line and bacterial filter 15 and be vented to atmosphere by the machine, and before being vented to atmosphere, the exhaled gas is monitored by the exhalation pressure sensor 11 and flows through the exhalation flow probe 10 and the exhalation valve 13, and the exhalation flow sensor 12 in parallel with the exhalation flow probe 10 may be a differential pressure sensor.

In this embodiment of the present application, the schematic structural diagram of the above-mentioned ventilator is a dual-limb respiratory pipeline structure, and the ventilator applied in this application is not limited to the ventilator with the above-mentioned structure, but can be applied to a ventilator with a single-limb respiratory pipeline structure. The ventilation interface for connection to the patient is not limited to the invasive interface such as a cannula, and may be a noninvasive ventilation interface such as a mask or nasal obstruction.

In the embodiment of the application, the air path structure comprises the turbine, so that a high-pressure air source is not needed, and the embodiment of the application is not limited to the structure, and can be also used for a respirator air path structure system without a built-in turbine and supplied by means of the high-pressure air source.

In the above-mentioned gas circuit structure of this application, there is an air suction valve in the rear end of turbine for adjust the flow and the pressure of breathing in, but this air suction valve also can omit in concrete embodiment, realizes the flow and the pressure regulation and control of breathing in through the quick acceleration and deceleration of turbine directly.

In the embodiment of the present application, the expiratory flow sensor is of differential pressure type, and the present application is not limited to differential pressure type expiratory flow sensor, but may be of thermal type.

In this embodiment of the present application, the oxygen concentration sensor in the gas path structure may be an electrochemical oxygen cell, or may be an ultrasonic oxygen concentration sensor, or may be a paramagnetic oxygen concentration sensor, which is not specifically limited in this application.

The embodiment of the application provides a PAV parameter adjusting method for a ventilator, the implementation main body of the method is the ventilation controller in fig. 2, and the ventilation controller may be an MCU, a PLC, or a device such as a server, a server cluster or a computer connected to the ventilator. The ventilation controller may receive various ventilation detection signals, such as flow, pressure, etc., from the drive and detection circuitry, and the ventilation detection signals may output various respiratory monitoring parameters, including, but not limited to, tidal volume, respiratory rate, minute ventilation, peak inspiratory pressure, positive end expiratory pressure, etc., after being processed by the ventilation controller. The ventilation controller may also be mediated by drive and detection circuitry to create control and/or controlled relationships with the various valves and turbines in the gas circuit configuration. As shown in fig. 4, the PAV parameter adjustment method for a ventilator may include steps S401 to S404:

s401, determining a plurality of sets of pre-ventilation characteristic parameters and corresponding initial sets of proportional assist ventilation PAV parameters corresponding to preset output times of the sine wave flow ventilation waveform based on the predetermined sine wave flow ventilation waveform.

The preset sine wave flow ventilation waveform is an output waveform in a preset ventilation controller, the sine wave flow ventilation waveform is a sine wave flow waveform in a capacity control mode, ventilation is carried out by the preset sine wave flow ventilation waveform as a pre-ventilation stage, the capacity control sine wave ventilation waveform is shown in fig. 5, and an inhalation flow target formula of the sine wave flow ventilation waveform is as follows:

F(t)＝(VT_set*pi)/(2*Ti)*sin(t*pi/Ti)

Wherein F (t) is flow, VT_set is target tidal volume set by a user through a human-computer interaction interface before pre-ventilation, pi is circumferential rate pi, ti is inspiration time of pre-ventilation, and Ti is related to set target respiratory rate; t is time in seconds.

When the inhalation-to-exhalation ratio is 1:2, the above ti=20/rr_set, rr_set is the target respiratory rate set by the user through the man-machine interface, and the unit is times/minute.

The preset output time includes a number of breaths of the patient, such as 3-6 breaths. And in the preset output time, the breathing machine outputs flow according to the sine wave flow ventilation waveform, and the ventilation controller collects characteristic parameters in the breathing process of each time and forms a pre-ventilation characteristic parameter set. Referring to fig. 5, the pre-ventilation characteristic parameter set includes: the peak inspiratory pressure ppreak (peak inspiratory pressure) under controlled sine wave ventilation (pre-ventilation), the end inspiratory pressure Peip under controlled sine wave ventilation, the measured tidal volume VT, the measured end expiratory pressure PEEP, and the flow rate F1 and the volume V1 at the moment corresponding to the peak inspiratory pressure ppreak. Since each breath will result in a set of pre-ventilation feature parameters, multiple sets of PAV parameters can be solved using multiple sets of feature parameters.

In an embodiment of the present application, determining, based on a predetermined sinusoidal flow ventilation waveform, a plurality of sets of pre-ventilation characteristic parameters and corresponding initial sets of proportional assist ventilation PAV parameters corresponding to preset output times of the sinusoidal flow ventilation waveform specifically includes:

first, the ventilation controller will generate a pre-ventilation trigger signal to cause the ventilator to supply pressurized gas in a sine wave flow ventilation waveform for a preset output time by the pre-ventilation trigger signal. The preset output time at least comprises the time of preset breathing times of the patient to be supplied with oxygen.

Next, the pre-ventilation detection information of each breath is determined by the flow rate and sensor module (oxygen flow rate sensor 3, oxygen concentration sensor 5, inhalation flow rate sensor 8, inhalation pressure sensor 9, inhalation pressure sensor 11, exhalation flow rate sensor 12) within a predetermined output time. The pre-ventilation detection information includes at least: flow, pressure, respiration start time and respiration end time.

And then analyzing the pre-ventilation detection information, and determining a pre-ventilation characteristic parameter set corresponding to each breath.

Specifically, as shown in fig. 5, the ventilation controller first determines the inhalation pressure data in the pre-ventilation detection information, and determines the inhalation pressure peak value ppreak and the inhalation end pressure value Peip in the inhalation pressure data. And determining a Positive End Expiratory Pressure (PEEP) value and a tidal Volume (VT) in the pre-ventilation detection information.

The method for determining the tidal volume in the pre-ventilation detection information specifically comprises the following steps:

as shown in the capacity curve of fig. 5, the flow of pre-ventilation detection information corresponding to one breath is integrated with the start time of the breath as the start point and the end time of the breath as the end point, so as to determine the maximum and minimum air intake capacity values of one breath.

And determining the initial tidal volume corresponding to one breath according to the maximum and minimum air suction capacity values and the first preset formula.

The first preset formula is as follows:

VTi＝(2×Vmax－Vmin)/2

VTi represents the tidal volume in the ith breath, vmax represents the maximum inspiratory capacity value, and Vmin represents the minimum inspiratory capacity value.

That is, from the number of breaths of pre-ventilation, a moving average of the tidal volume of multiple breaths is calculated as the tidal volume of the pre-ventilation phase, such as: vt_real=Σvti/n, vt_real is the tidal volume in the pre-ventilation detection information.

And determining a pending PAV parameter set corresponding to each pre-ventilation characteristic parameter set according to a preset initial PAV parameter determination model. The set of pending PAV parameters includes at least a capacity assist parameter and a flow assist parameter.

Specifically, the capacity assist parameter is determined from the initial PAV parameter determination model, the inspiratory terminal pressure value, the expiratory terminal positive pressure value, and the tidal volume.

Substituting the inspiration terminal pressure value, the expiration terminal pressure value and the tidal volume into a capacity auxiliary parameter calculation formula of the initial PAV parameter determination model:

KV(T0)＝(Peip-PEEP)/VT

wherein KV (T0) is a capacity auxiliary parameter in the T0 th breath.

And substituting the flow data F1 and the volume data V1 of the inspiration pressure peak value Ppeak, the volume auxiliary parameter KV (T0), the expiration end positive pressure value PEEP and the inspiration pressure peak value corresponding time into a flow auxiliary parameter calculation formula to determine a flow auxiliary parameter.

Flow auxiliary parameter calculation formula: KF (T0) = (ppreak-KV (T0) ×v1—peep)/F1

Wherein KF (T0) is a flow auxiliary parameter in the T0 th breath.

An initial set of PAV parameters is determined based on each pending set of PAV parameters.

In the pre-ventilation (3-6 times of respiration), multiple groups of pending PAV parameter sets such as { KV (T0), KF (T0) }, { KV (T1), KF (T1) } … … can be obtained, and according to the obtained multiple groups of pending PAV parameter sets, capacity auxiliary parameters and average values of flow auxiliary parameters are calculated respectively to obtain initial PAV parameter sets { KV (T), KF (T) }.

S402, in the case of performing PAV ventilation with the initial set of PAV parameters, ventilation detection information from the flow and sensing module is acquired.

The ventilation detection information is detection information when the ventilator ventilates in the PAV mode. The detection information comprises at least one or more of the following: flow, pressure.

After the initial PAV parameter set is obtained, the breathing machine outputs mixed gas according to the initial PAV parameter set, and the pressure target of the breathing machine at each inspiration time point in the breathing process of the patient is as follows:

Ptarget(t)＝KF(T)*F(t)+KV(T)*V(t)+PEEP

wherein Ptarget (t) is the pressure value corresponding to the time point t, and V (t) is the capacity value corresponding to the time point t, and can be obtained by integrating the flow.

In the ventilation process, the ventilation controller can acquire flow and pressure data in the breathing process in real time.

S403, based on the ventilation detection information and the preset auxiliary ventilation information, matching a preset parameter updating strategy to update the initial PAV parameter set according to the parameter updating strategy.

In this embodiment of the present application, based on ventilation detection information and preset auxiliary ventilation information, a preset parameter updating policy is matched, which specifically includes:

and respectively determining the inverse of the difference between the breath termination time and the breath start time of each breath of the historical preset times of continuous breaths in the ventilation detection information.

The predetermined number of histories is a predetermined number of breaths before the current breath. The predetermined number of times of history may be set by the user, and the numerical value of the predetermined number of times is not particularly limited in this application.

And calculating the product value of the reciprocal of each difference value and the preset unit time length, and taking each product value as the single respiratory frequency of each breath. And taking the moving average value of each single breathing frequency as the breathing frequency value of the current breath.

That is, the single breath rate of a predetermined number of breaths historically may be averaged as the breath rate value for the current breath. For example, at the beginning of each inspiration (i.e. the ending time te of the previous breath), the duration tie=te-t 0 of the previous breath is calculated, and the reciprocal of the duration Tie (unit seconds) of the previous breath is multiplied by 60 to obtain the current frequency RRi calculated by the present breath, and the frequency of the previous predetermined number of breaths (n times) is taken as the breathing frequency rr_real, i.e. rr_real=Σrri/n.

Next, a tidal volume of the current breath is determined based on the flow of ventilation detection information.

The calculation method of the tidal volume is described in detail in the embodiment of S401 above, and will not be described herein.

And then, determining a corresponding parameter updating strategy according to the matching result of the breathing frequency value, the tidal volume and the auxiliary ventilation information. The auxiliary ventilation information comprises a preset target respiratory rate value and a target tidal volume.

Specifically, a plane rectangular coordinate system is established with the respiratory rate value RR as an abscissa and the respiratory capacity VT as an ordinate.

Generating a plurality of grade interval dividing neighborhoods consisting of different grade interval dividing parameters, target respiratory rate values and target tidal volume according to the target respiratory rate values and the target tidal volume of the auxiliary ventilation information and a plurality of preset grade interval dividing parameters.

The target respiratory rate value and the target tidal volume are set by a user before the pre-ventilation stage, and the corresponding areas of the grading interval division field comprise a moderate area, a moderate poor area and a high poor area. The state space of capacity/frequency composition is divided into three regions, the first being a region very close to the target capacity/target frequency (moderate region), the second region (moderate poor region) and the third region (high poor region) being increasingly distant from the target state values (target respiratory rate value, target tidal volume). The three region division rules are specifically as follows:

moderate area:

75％*VT_set≤VT_real≤150％*VT_set；

and is also provided with

75％*RR_set≤RR_real≤150％*RR_set；

Moderate bad area:

150％*VT_set<VT_real≤200％*VT_set；

or alternatively

50％*VT_set≤VT_real<75％*VT_set；

Or alternatively

150％*RR_set<RR_real≤200％*RR_set；

Or alternatively

50％*RR_set≤RR_real<75％*RR_set；

Poor height area:

VT_real>200％*VT_set；

or alternatively

VT_real<50％*VT_set；

Or alternatively

RR_real>200％*RR_set；

Or alternatively

RR_real<50％*RR_set；

Vt_real and rr_real are the measured tidal volume and the respiratory rate value of the current breath, respectively, and vt_set and rr_set are the target tidal volume and the target respiratory rate value, respectively.

The neighborhood is divided according to each level interval, and the level interval division area is generated in a plane rectangular coordinate system as shown in fig. 6. The figure includes a moderate region 601, a moderate region 602, a high region 603, and a target point 604 corresponding to the target tidal volume and the target respiratory rate value.

The ventilation controller determines a grade interval dividing region matched with coordinates corresponding to the breathing frequency value and the tidal volume, so as to determine a preset parameter updating strategy according to the matched grade interval dividing region. The parameter updating strategy comprises a parameter adjusting amplitude and a parameter adjusting direction in the PAV parameter set.

The parameter updating policy may be stored in the ventilation controller in advance, or may be stored in an external database connected to the ventilation controller in a network or wired manner. The parameter updating strategy can be specifically set by a user, for example, in a moderate area, the adjustment amount is small (slow adjustment), such as 10% adjustment amount based on the previous time; in the poor medium area, the adjustment amount is increased (medium speed adjustment), such as 50% adjustment amount based on the previous time; in the area of poor height, the adjustment is maximum (quick adjustment), such as 200% on the basis of the previous adjustment.

If the amplitude of each adjustment is delta%, the auxiliary parameters after each breath update corresponding to the parameter adjustment amplitude formula are as follows:

KF(T)＝KF(T-1)*(1±Δ％)

KV(T)＝KV(T-1)*(1±Δ％)

wherein T-1 in KF (T-1) and KV (T-1) represent auxiliary parameters in the previous breath.

The auxiliary parameter adjustment principle provided by the application is simple and easy to realize, and the two auxiliary coefficients are the capacity auxiliary coefficient KV and the flow auxiliary coefficient KF respectively, and the adjustment of the two auxiliary coefficients is decoupled, that is, the adjustment of the two auxiliary coefficients only depends on the independent state variables. The adjustment of the capacity assist factor KV depends on the tidal volume VT, while the adjustment of the flow assist factor KF depends on the breathing frequency RR.

Rules of parameter adjustment direction of capacity assistance parameters:

if vt_real is lower than vt_set, KV is increased, i.e., the above-mentioned adjustment amplitude formula KV (T) =kv (T-1) ×1+Δ%;

if VT_real is higher than VT_set, the KV is reduced, namely the regulation amplitude formula is as follows: KV (T) =kv (T-1) ×1- Δ%;

rule of parameter adjustment direction of flow auxiliary coefficient:

if rr_real is lower than rr_set, KF is turned high, i.e. KF (T) =kf (T-1) ×1+Δ%;

if rr_real is higher than rr_set, KF is turned down, KF (T) =kf (T-1) ×1- Δ%;

the above example is illustrated with a positive value for Δ%, and it will be understood by those skilled in the art that if Δ% is negative, the sign in the formula corresponding to the adjustment rule is opposite to when Δ% is positive.

In this embodiment of the present application, the updated PAV parameter set generates a PAV control instruction, so as to control, in real time, a pressure value (Ptarget (T) =kf (T) ×f (T) +kv (T) ×v (T) +peep) corresponding to a PAV mode of the ventilator according to the updated PAV parameter set. During the respiration of a patient, the respiratory flow and pressure are time-varying, and the updated PAV parameter set may be unreasonable and need to be adjusted in real time. The application provides the following embodiments, specifically including:

and taking the updated PAV parameter set as an initial PAV parameter set, and performing PAV ventilation by using the updated initial PAV parameter set to acquire corresponding ventilation detection information.

And then, according to the matching result of the ventilation detection information and the auxiliary ventilation information corresponding to each breath, determining whether the parameters in the initial PAV parameter set are parameters to be updated.

That is, ventilation may be performed with the updated initial PAV parameters again after updating the initial PAV parameter set, and acquisition of ventilation detection information may be performed. According to the specific embodiment of the parameter updating strategy, the ventilation detection information and the auxiliary ventilation information are matched in real time, and whether the corresponding parameter updating strategy is matched or not is determined; if the parameter updating strategy is matched, the parameters in the current initial PAV parameter set are parameters to be updated.

Under the condition that parameters in the initial PAV parameter set are to be updated, before each breath starts, updating the parameters in the initial PAV parameter set until a matching result of the breathing frequency value, the tidal volume and the auxiliary ventilation information corresponding to the ventilation detection information meets a preset condition.

The preset condition is that the absolute value of the difference value respectively corresponding to the respiratory rate value and the target respiratory rate value and the tidal volume and the target tidal volume is smaller than the preset value. The preset value is set by the user, and can be understood as an error value within an error allowable range, and the preset value is not particularly limited in this application.

In the embodiment of the application, the auxiliary parameters provided above have 2 possibilities of adjusting up and down, and each adjustment has 3 possibilities of slow speed, medium speed and fast speed. That is, there are 2*3 =6 possibilities for adjustment of each auxiliary coefficient.

The regulation rules of the capacity assist parameters are undisputed, and low tidal volumes naturally require high capacity assist pressures and vice versa.

The regulation rules for the flow auxiliary parameters are explained as follows: in the case of a fixed tidal volume and respiratory ratio, if the respiratory rate is high, the inspiration time is short and the corresponding inspiratory average flow is high; conversely, if the respiratory rate is low, the inspiration time is long and the corresponding inspiratory average flow is low. It follows that a high respiratory rate is highly likely to be caused by a high average flow rate of inspiration, and a low respiratory rate is similarly highly likely to be caused by a low average flow rate of inspiration. Therefore, when the respiratory rate is higher than the target value, the purpose of the flow auxiliary coefficient is to reduce the average flow of inspiration (so as to make the waveform of the flow of inspiration more gentle) and to pull the respiratory rate closer to the target value; conversely, when the respiratory rate is lower than the target value, the flow auxiliary parameter is regulated up, so that the reasonable effect is achieved.

In other words, for patients with high airway resistance (e.g., chronic obstructive pulmonary disease (chronic obstructive pulmonary disease, COPD)) the respiratory rate is more likely to be slower than normal, and the flow assist factor increases accordingly (to allow faster delivery of air, higher inspiratory flow); in patients with low airway resistance (e.g., patients with Acute Respiratory Distress Syndrome (ARDS)), the respiratory rate is more likely to be faster than normal, and the flow assist factor is correspondingly reduced (to slow down the delivery of air, and to slow down the inspiratory flow). These all conform to the practical experience of clinical mechanical ventilation.

And S404, generating PAV control instructions based on the updated PAV parameter set so as to control the corresponding pressure value of the PAV mode of the breathing machine in real time according to the updated PAV parameter set.

In the embodiment of the application, the method is based on updated data

The PAV parameter set generates a PAV control instruction so as to control the corresponding pressure value of the PAV mode of the breathing machine in real time according to the updated PAV parameter set, and specifically comprises the following steps:

after generating the PAV control command, determining a pending pressure value and a pending pressure change curve output by the PAV parameter set according to a second preset formula.

The second preset formula is Ptarget (T) =kf (T) ×f (T) +kv (T) ×v (T) +peep.

The suction pressure is the target of the time variation, proportional to the flow F (t) and the volume V (t) at each instant. The present application may employ a pressure controller to monitor respiratory pressure.

Before inputting Ptarget (t) into a pressure tracking controller, limiting and adjusting each undetermined pressure value in the undetermined pressure change curve according to the slope value of the undetermined pressure change curve, the extreme pressure value corresponding to the extreme point of the undetermined pressure change curve and the corresponding limiting quantity, so that each undetermined pressure value after limiting and adjusting is input into the pressure controller of the breathing machine, and the corresponding pressure value of the PAV mode of the breathing machine is controlled in real time. The limit amount includes a slope value limit amount and a maximum value limit amount. The limiting quantity is used to adjust the value of the respective pressure value to be determined.

The above-mentioned slope value limit amount, maximum value limit amount is preset by the user, and the slope limit is to say that if the pressure rises too fast, this will not only go beyond the capacity range of the driver, but also cause uncomfortable feeling of patient inhalation overshoot, and thus it is necessary to impose a limit on the rising speed thereof. Specifically, each time the pressure target is limited to an increase from the previous actual pressure target by less than a reasonable amount, i.e., a slope value limit is provided.

The maximum limit is also for safety reasons, and the pressure target is not to exceed the pressure warning limit of the ventilator. In a specific implementation, once the calculated pressure target value exceeds the maximum value limit (which is lower than the pressure warning limit), the target value Ptarget (t) should be made equal to the maximum limit.

The pressure controllers (pressure tracking controllers) described above may be built using various control theory including, but not limited to, feed forward control, PID control, adaptive control, robust control, and the like, as well as combinations thereof, as not specifically limited in this application.

In the embodiment of the present application, in the pressure control of the proportional pressure assisted ventilation PAV, the flow chart of the pressure control is shown in fig. 7, and includes:

the flow and sensing modules perform

pressure detection

702 and 703 from the vent line 701, compare 704 the measured pressure Preal with the pressure target after slope and maximum limit, integrate the flow to obtain the volume V (t), perform volume monitoring 705, and perform pressure target generation 706 on the volume V (t) and the flow F (t), respectively. The pressure target generation 706 calculates a pressure target Ptarget (t) from the flow rate F (t) and the capacity V (t). The pressure target is then slope and maximum limited 707, and the slope and maximum limited 707 processed pressure target is compared 704 to the measured pressure Preal. The pressure tracking controller 708 is then input, and the flow F (t), the volume V (t) are also included in the pressure tracking controller 708. The pressure tracking controller 708 adjusts the pressure gradient value, etc. according to the analysis control result of the pressure target, that is, adjusts the pressure target such that the target value Ptarget (t) is equal to the maximum limit amount, and further controls the turbine or the proportional valve 709 to adjust the output pressure value of the ventilator, and provides the mixed gas to the patient 7010 through the ventilation pipeline 701.

In the embodiment of the present application, after the PAV parameter sets are updated, each PAV parameter set corresponding to the preset breath and the parameter updating direction of each PAV parameter set are determined. The parameter updating directions include a positive updating direction and a negative updating direction. And updating the parameter updating direction of the current breath and updating the PAV parameter set according to the parameter updating direction and the parameter distance variation of each parameter of the PAV parameter set and the corresponding parameter in the auxiliary ventilation information.

In other words, in the process of monitoring the PAV parameters in real time, the trend of adjustment can be monitored, when the PAV parameters are adjusted, if adjustment cannot be as expected to approach the final target, but is far away from the target, that is, the tidal volume and the respiratory rate are not close to the target tidal volume and the target respiratory rate after the PAV parameters are adjusted, the PAV parameters can be stopped to be adjusted, and even the PAV parameters can be adjusted in the opposite direction. For example, an increase in the PAV parameter is originally performed and a decrease in the PAV parameter value is now performed.

In addition, if the target tidal volume and the target respiratory rate are still inaccessible after multiple adjustments, the present application may issue an alarm signal, such as a sound, text, etc. In the event that multiple adjustments are not effective, it is also a reasonable option to return to the control of the initial controlled sine wave pre-ventilation, as this application is not specifically limited.

In one embodiment of the present application, the value ranges of the individual auxiliary parameters (capacity auxiliary parameter, flow auxiliary parameter), any adjustment should be limited to a maximum range and a minimum range, and the adjustment ranges of these auxiliary coefficients should also be different for different patient populations, such as adults, children. The limit value of the value range is set by a user, and the user can set by self according to adults or children or people with different physique, and the application is not particularly limited.

In the method for adjusting the PAV parameters of the ventilator provided in the embodiment of the present application, fig. 8 provides a schematic use flow chart of PAV parameter adjustment, as shown in fig. 8, which specifically includes:

s801, setting a target tidal volume VT_set and a target respiratory rate RR_set;

s802, performing capacitance control sine wave test ventilation;

s803, initial auxiliary parameters KF (T0) and KV (T0) are measured;

s804, proportional pressure assisted ventilation, PAV;

s805, monitoring the actual tidal volume VT_real and the respiratory rate RR_real;

s806, automatically adjusting auxiliary parameters KF (T) and KV (T);

s807, regulatory exception handling and alerting.

And updating the parameter updating direction of the current breath, sending out an alarm signal and the like.

According to the scheme, the pre-ventilation step of outputting the sine wave flow ventilation waveform is performed, so that a user does not need to guess the airway resistance and the lung elasticity of a patient, and the user does not need to set auxiliary proportion parameters, and the initial PAV parameters can be obtained. And, the tidal volume and the breathing frequency familiar to the user are used as control targets, and according to the actual tidal volume and the breathing frequency monitored by each time of breathing and the position of the tidal volume and the breathing frequency in a breathing state space region, the auxiliary parameters (volume auxiliary parameters and flow auxiliary parameters) of the proportional pressure auxiliary ventilation PAV are automatically adjusted in three gears (slow speed, medium speed and fast speed), so that the degree of freedom of the tidal volume and the breathing frequency of the breathing of the patient in autonomous control is ensured.

The flow auxiliary parameter and the capacity auxiliary parameter are adjusted in a decoupling way, and the flow auxiliary parameter is adjusted so that the actual respiratory frequency tends to be the set respiratory frequency; the capacity assist parameter is adjusted in order to bring the actual tidal volume towards the set tidal volume. The method overcomes the defect that the mode parameters are set by a user without the basis under the existing proportional pressure auxiliary mode, and the new mode is more suitable for the conventional thinking mode of setting the ventilation mode by the user. The mode is efficient and understandable without the user knowing the information of the respiratory mechanics parameters such as airway resistance and lung compliance.

The utility model provides a breathing machine of PAV parameter adjustment mode has both reached the clinical purpose of setting for target direction control, also makes the patient be in a comfortable and safe ventilation state all the time. And the auxiliary parameters of every breath of the application are established on the basis of the auxiliary parameters of the previous breath, so that PAV parameter adjustment is more scientific, negative feedback and positive feedback mechanisms are combined to carry out PAV parameter adjustment, the application provides the effect that the patient can use more safely, more comfortably and more easily, and the use experience of the patient to the breathing machine PAV mode is improved.

Fig. 9 is a schematic structural diagram of a PAV parameter adjusting device for a breathing machine according to an embodiment of the present application, where the device includes:

a determining module 901, configured to determine a plurality of pre-ventilation characteristic parameter sets and corresponding initial proportional assist ventilation PAV parameter sets corresponding to preset output times of the sinusoidal flow ventilation waveform based on the predetermined sinusoidal flow ventilation waveform.

An acquisition module 902 for acquiring ventilation detection information from the flow and sensing module in the case of PAV ventilation with an initial set of PAV parameters. The ventilation detection information is detection information when the ventilator ventilates in the PAV mode. The detection information comprises at least one or more of the following: flow, pressure.

The matching module 903 is configured to match a preset parameter updating policy based on the ventilation detection information and the preset auxiliary ventilation information, so as to update the initial PAV parameter set according to the parameter updating policy.

The generating module 904 is configured to generate a PAV control instruction based on the updated PAV parameter set, so as to control, in real time, a pressure value corresponding to a PAV mode of the ventilator according to the updated PAV parameter set.

The determining module 901 is specifically configured to:

a pre-ventilation trigger signal is generated to enable the ventilator to supply pressurized gas in a sine wave flow ventilation waveform within a preset output time through the pre-ventilation trigger signal. The preset output time at least comprises the time of the preset breathing times of the patient to be ventilated.

And determining pre-ventilation detection information of each breath in preset output time through the flow and sensing module. The pre-ventilation detection information includes at least: flow, pressure, respiration start time and respiration end time.

Analyzing the pre-ventilation detection information, and determining a pre-ventilation characteristic parameter set corresponding to each breath.

The determining module 901 is specifically configured to:

the inspiratory pressure data in the pre-ventilation detection information is determined, and the inspiratory pressure peak value and the inspiratory terminal pressure value in the inspiratory pressure data are determined. and

The positive end-expiratory pressure value and tidal volume in the pre-ventilation detection information are determined.

According to a preset initial PAV parameter determining model, determining undetermined PAV parameter sets corresponding to each pre-ventilation characteristic parameter set, wherein the method specifically comprises the following steps:

and determining the capacity auxiliary parameter according to the inspiration terminal pressure value, the expiration terminal positive pressure value and the tidal volume.

The flow auxiliary parameter is determined based on the inspiratory pressure peak, the volume auxiliary parameter, the positive end expiratory pressure value, and the flow data and volume data at the time corresponding to the inspiratory pressure peak.

The determining module 901 is specifically configured to:

and integrating the flow of the pre-ventilation detection information corresponding to one breath by taking the starting moment of the breath as a starting point and the ending moment of the breath as an ending point to determine the maximum air suction capacity value and the minimum air suction capacity value of one breath.

The matching module 903 is specifically configured to:

and respectively determining the inverse of the difference between the breath termination time and the breath start time of each breath of the historical preset times of continuous breaths in the ventilation detection information. The predetermined number of histories is a predetermined number of breaths before the current breath.

A tidal volume of the current breath is determined based on the flow of ventilation detection information.

And determining a corresponding parameter updating strategy according to the breathing frequency value, the tidal volume and the matching result of the auxiliary ventilation information. The auxiliary ventilation information comprises a preset target respiratory rate value and a target tidal volume.

The matching module 903 is specifically configured to:

and establishing a plane rectangular coordinate system by taking the respiratory rate value as an abscissa and the respiratory capacity as an ordinate.

And dividing the neighborhood according to each grade interval, and generating a grade interval dividing region in a plane rectangular coordinate system.

And determining a grade interval dividing region matched with coordinates corresponding to the respiratory rate value and the tidal volume, so as to determine a preset parameter updating strategy according to the matched grade interval dividing region. The parameter updating strategy comprises a parameter adjusting amplitude and a parameter adjusting direction in the PAV parameter set.

The matching module 903 is further configured to:

And determining whether the parameters in the initial PAV parameter set are parameters to be updated or not according to the matching result of the ventilation detection information and the auxiliary ventilation information corresponding to each breath.

If yes, updating parameters in the initial PAV parameter set before each breath starts, until a matching result of the breathing frequency value, the tidal volume and the auxiliary ventilation information corresponding to the ventilation detection information meets a preset condition. The preset condition is that the absolute value of the difference value respectively corresponding to the respiratory rate value and the target respiratory rate value and the tidal volume and the target tidal volume is smaller than the preset value.

The generating module 904 is specifically configured to:

And limiting and adjusting each undetermined pressure value in the undetermined pressure change curve according to the slope value of the undetermined pressure change curve, the extreme pressure value corresponding to the extreme point of the undetermined pressure change curve and the corresponding limiting quantity, so that each undetermined pressure value after limiting and adjusting is input into a pressure controller of the breathing machine, and the corresponding pressure value of the PAV mode of the breathing machine is controlled in real time. The limit amount includes a slope value limit amount and a maximum value limit amount. The limiting quantity is used to adjust the value of the respective pressure value to be determined.

The apparatus further comprises:

and the parameter updating determining module is used for determining each PAV parameter set corresponding to the preset breath and the parameter updating direction of each PAV parameter set after updating the PAV parameter set. The parameter updating directions include a positive updating direction and a negative updating direction.

And the parameter updating direction updating module is used for updating the current breathing parameter updating direction and updating the PAV parameter set according to the parameter updating direction and the parameter distance variation of each parameter of the PAV parameter set and the corresponding parameter in the auxiliary ventilation information.

All embodiments in the application are described in a progressive manner, and identical and similar parts of all embodiments are mutually referred, so that each embodiment mainly describes differences from other embodiments. In particular, for the device embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and reference is made to the description of the method embodiments in part.

The device and the method provided in the embodiments of the present application are in one-to-one correspondence, so that the device also has similar beneficial technical effects as the corresponding method, and since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the device are not described here again.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.

Claims

1. A method of PAV parameter adjustment for a ventilator, the method comprising:

2. The method of claim 1, wherein determining a plurality of sets of pre-ventilation characteristic parameters and their corresponding initial set of proportional assist ventilation, PAV, parameters corresponding to a preset output time of a sinusoidal flow ventilation waveform based on a predetermined sinusoidal flow ventilation waveform, specifically comprises:

generating a pre-ventilation trigger signal to enable the ventilator to supply pressurized gas in the sine wave flow ventilation waveform within the preset output time through the pre-ventilation trigger signal; the preset output time at least comprises the time of preset breathing times of the patient to be ventilated;

3. The method according to claim 2, wherein analyzing the pre-ventilation detection information and determining the set of pre-ventilation characteristic parameters corresponding to each breath specifically comprises:

determining the inspiration pressure data in the pre-ventilation detection information, and determining an inspiration pressure peak value and an inspiration end pressure value in the inspiration pressure data; and

4. The method of claim 3, wherein determining the tidal volume in the pre-ventilation detection information, in particular comprises:

Taking the respiration starting moment as a starting point and the respiration ending moment as an ending point, carrying out integral processing on the flow of the pre-ventilation detection information corresponding to one respiration, and determining a maximum air suction capacity value and a minimum air suction capacity value of the one respiration;

5. The method of claim 1, wherein matching a preset parameter update policy based on the ventilation detection information and preset ventilation assist information, specifically comprises:

respectively determining the historical preset times of continuous respiration and the reciprocal of the difference value between the respiration ending time and the respiration starting time of each respiration in the ventilation detection information; the predetermined number of histories is a predetermined number of breaths prior to the current breath;

6. The method according to claim 5, wherein determining the corresponding parameter updating policy according to the matching result of the respiratory rate value, the tidal volume and the assisted ventilation information, specifically comprises:

establishing a plane rectangular coordinate system by taking a respiratory frequency value as an abscissa and respiratory capacity as an ordinate;

7. The method of claim 6, wherein the method further comprises:

taking the updated PAV parameter set as an initial PAV parameter set, and performing PAV ventilation by using the updated initial PAV parameter set to acquire corresponding ventilation detection information;

8. The method according to claim 1, wherein generating a PAV control command based on the updated set of PAV parameters so as to control, in real time, a pressure value corresponding to a PAV mode of the ventilator according to the updated set of PAV parameters, comprises:

After the PAV control instruction is generated, determining a undetermined pressure value and a undetermined pressure change curve which are output by the PAV parameter set according to a second preset formula;

9. The method according to claim 1, wherein the method further comprises:

after updating the PAV parameter sets, determining each PAV parameter set corresponding to preset respiration and the parameter updating direction of each PAV parameter set; the parameter updating direction comprises a positive updating direction and a negative updating direction;

10. A PAV parameter adjustment device for a ventilator, said device comprising: