Recognition of asynchrony in artificial respiration

Abstract

The invention relates to a system for identifying an asynchronism between a breathing machine and a living being connected to the breathing machine and an associated, partially automatic control of the breathing machine. The system for identifying an asynchronism between a breathing machine and a living being comprises at least a breathing machine, wherein the breathing machine comprises at least a sensor unit, a preprocessing unit, a calculation unit, an identification unit, a memory unit, a monitoring unit, a control unit and a blower unit / valve unit, wherein the identification unit identifies an asynchronism between the breathing machine and the living being depending on breathing parameters of the living being.

Description

TECHNICAL FIELD

[0001] The present invention relates to a system for identifying an asynchrony between a breathing machine and a living being connected to the breathing machine and a partly automated control of the breathing machine associated therewith. BACKGROUND

[0002] Humans inhale and exhale approximately 20,000 times per day. In order to control a breathing machine, it is a considerable task to correctly identify these breaths and to trigger the breathing support at the right point in time. Here, the exact algorithm for triggering the breaths is decisive for the success of the therapy and the health of the patient / user. Usually, the sensitivity for triggering the breaths is manually set by the doctor or the caregiver who performs the therapy. However, the setting thus chosen can not always optimally adapt to the individual needs of the patient during the therapy, since the necessary triggering sensitivity changes or can change due to a change of position, different sleep stages, etc. SUMMARY

[0003] It is therefore the task of the present invention to provide a system for effectively and safely breathing a living being. This task is solved by the system and method according to the present invention.

[0004] The system for identifying an asynchrony between a breathing machine and a living being comprises at least one breathing machine, wherein the at least one breathing machine comprises at least

[0005] - a sensor unit

[0006] - a preprocessing unit

[0007] - a computing unit

[0008] - an identification unit

[0009] - a memory unit

[0010] - a monitoring unit

[0011] - a control unit

[0012] - a blower unit / valve unit,

[0013] wherein the identification unit identifies an asynchrony between the breathing machine and the living being depending on breathing parameters of the living being.

[0014] In some embodiments of the system, the breathing parameters comprise at least pressure and / or flow and / or are determined by pressure and / or flow.

[0015] In some embodiments of the system, the control unit controls the blower unit / valve unit depending on the asynchrony identified by the identification unit.

[0016] In some embodiments of the system, the identification of asynchrony is performed during the use of the artificial respirator by the living being. That is, the asynchrony identification is performed during the use of the artificial respirator by the living being.

[0017] In some embodiments of the system, the identification unit identifies missed breaths and brief breath delays.

[0018] In some embodiments of the system, the identification unit evaluates missed breaths and brief breath delays as asynchronies.

[0019] In some embodiments of the system, the identification unit identifies missed breaths by analyzing the Atemanstrengungsfluss, the expected breath flow and the determined breath flow.

[0020] In some embodiments of the system, the identification unit identifies brief breath delays by analyzing the Atemanstrengungsfluss, the expected breath flow and the determined breath flow.

[0021] In some embodiments of the system, the identification unit identifies false triggers and evaluates the false triggers as asynchronies.

[0022] In some embodiments of the system, the calculation unit determines the Atemanstrengungsfluss from the expected breath flow and the determined breath flow.

[0023] In some embodiments of the system, the calculation unit determines the expected breath flow from the Atemwegswiderstand R and the Lungelastizität E.

[0024] In some embodiments of the system, the calculation unit determines the expected breath flow from an average of the Atemwegswiderstand R and an average of the Lungelastizität E.

[0025] In some embodiments of the system, the calculation unit calculates the Atemwegswiderstand R and the Lungelastizität E from measured values measured by the sensor unit and preprocessed by the preprocessing unit.

[0026] In some embodiments of the system, the control unit automatically adjusts the trigger sensitivity of the artificial respirator depending on missed breaths and brief trigger delays identified by the identification unit.

[0027] In some embodiments of the system, the control unit automatically adjusts the trigger sensitivity of the artificial respirator depending on missed breaths, brief trigger delays and false triggers identified by the identification unit.

[0028] In some embodiments of the system, the Atemwegswiderstand R and the Lungelastizität E are determined by the calculation unit by a mathematical lung model.

[0029] In some embodiments of the system, the respiratory resistance R and the lung elasticity E are determined by the computing unit by multiple linear regression and a one-compartment lung model (Ein-Kompartment-Lungenmodell).

[0030] In some embodiments of the system, the identifying unit identifies the missed breaths depending on at least one of the following features of the respiratory effort flow, the expected respiratory flow and the determined respiratory flow:

[0031] - the local maximum of the determined respiratory flow is located between two minima of the respiratory effort flow

[0032] - the difference between the time position of the local maximum of the respiratory effort flow and the corresponding left minimum

[0033] - the difference between the time position of the local maximum of the respiratory effort flow and the corresponding right minimum

[0034] - the difference between the value of the local maximum of the respiratory effort flow and the corresponding left minimum

[0035] - the difference between the value of the local maximum of the respiratory effort flow and the corresponding right minimum

[0036] - the expected respiratory flow at the time point of the local maximum of the respiratory effort flow

[0037] - the time between the local maximum of the respiratory effort flow and the expected triggering time point.

[0038] In some embodiments of the system, the identifying unit identifies the missed breaths depending on at least one of the following features of the respiratory effort flow, the expected respiratory flow and the determined respiratory flow:

[0039] - the local maximum of the determined respiratory flow must be located between two minima of the respiratory effort flow

[0040] - the difference between the time position of the local maximum of the respiratory effort flow and the corresponding left minimum

[0041] - the difference between the time position of the local maximum of the respiratory effort flow and the corresponding right minimum

[0042] - the difference between the value of the local maximum of the respiratory effort flow and the corresponding left minimum

[0043] - the difference between the value of the local maximum of the respiratory effort flow and the corresponding right minimum

[0044] - the expected respiratory flow at the point in time of the local maximum of the respiratory effort flow

[0045] - the time between the local maximum of the respiratory effort flow and the expected triggering point in time.

[0046] In some embodiments of the system, the computing unit calculates the expected triggering point in time by an average of the lengths of previous breaths.

[0047] In some embodiments of the system, the computing unit calculates the expected triggering point in time by an average of the lengths of the last autonomous breaths and the last expected triggering times.

[0048] In some embodiments of the system, the average is a weighted average.

[0049] In some embodiments of the system, the identifying unit identifies whether the triggering delay is a short triggering delay depending on the value of the triggering delay determined by the computing unit.

[0050] In some embodiments of the system, the identifying unit identifies and determines the triggering delay by a misalignment between the respiratory effort of the living being and the triggering of the artificial breathing machine.

[0051] In some embodiments of the system, the identifying unit identifies a short triggering delay if the triggering delay is assessed to be too short for the respiratory effort of the living being.

[0052] In some embodiments of the system, the triggering delay is identified as a short triggering delay if the triggering delay is smaller or equal to a threshold value, wherein the threshold value is chosen in the range between 0 seconds and 0.5 seconds, preferably between 0 seconds and 0.25 seconds, particularly preferably between 0 seconds and 0.15 seconds.

[0053] In some embodiments of the system, the threshold value for identifying a short triggering delay is 0.1 seconds.

[0054] In some embodiments of the system, the breath pre-given by the artificial breathing machine is not investigated in terms of triggering delay, wherein the breath pre-given by the artificial breathing machine is not triggered by the respiratory effort of the living being.

[0055] In some embodiments of the system, the control unit automatically adapts the triggering sensitivity depending on the number of short triggering delays identified and missed breaths within a time interval.

[0056] In some embodiments of the system, the time interval is between 0.5 minutes and 5 minutes, preferably between 1 minute and 3 minutes.

[0057] In some embodiments of the system, in case of a leak flow rate greater than a threshold value between 15 l / min and 50 l / min, the triggering sensitivity is set in the form of an average triggering sensitivity determined including triggering sensitivities from previous time periods with a leak flow rate smaller than the threshold value.

[0058] In some embodiments of the system, in case of a leak flow rate greater than 25 l / min, the triggering sensitivity is set in the form of an average triggering sensitivity determined including triggering sensitivities from previous time periods with a leak flow rate smaller than 25 l / min.

[0059] In some embodiments of the system, the triggering sensitivity describes a parameter according to which the artificial ventilator recognizes a breath of the living being and triggers support of the artificial respiration, wherein the parameter comprises at least one threshold value of the breath flow.

[0060] In some embodiments of the system, the triggering sensitivity can be set manually and automatically.

[0061] In some embodiments of the system, the automatic setting of the triggering sensitivity can set a lower threshold value of the parameter for triggering than is possible with the manual setting.

[0062] In some embodiments of the system, the parameters for setting the triggering sensitivity are summarized in an abstract, unitless value, wherein the value extends from 0 to 8, wherein a low value reproduces a high triggering sensitivity and a high value reproduces a low triggering sensitivity.

[0063] In some embodiments of the system, values from 0 to 3 are used for the automatic setting of the triggering sensitivity and values from 1 to 8 are used for the manual setting.

[0064] In some embodiments of the system, the level of the triggering sensitivity is defined at least according to a threshold value of the breath flow.

[0065] In some embodiments of the system, the artificial ventilator is set up and configured to provide a suggestion for the manual setting of the triggering sensitivity according to the recognized missed breaths and / or short triggering delays.

[0066] In some embodiments of the system, the artificial ventilator is set up and configured to generate an alarm in case of a threshold value of missed breaths and / or short triggering delays.

[0067] In some embodiments of the system, the artificial respirator is set up and configured to identify an adverse setting of the artificial respirator using at least the missed breaths and / or the short triggering delay identified by the identifying unit.

[0068] In some embodiments of the system, the artificial respirator is set up and configured to identify an intrinsic PEEP using at least the missed breaths and / or the short triggering delay identified by the identifying unit.

[0069] In some embodiments of the system, the respiratory effort flow is filtered by a low-pass filter and the calculating unit calculates the triggering delay using the filtered respiratory effort flow.

[0070] In some embodiments of the system, the artificial respirator is set up and configured to identify an early expiration triggering.

[0071] In some embodiments of the system, the artificial respirator is set up and configured to assess the early expiration triggering as asynchronous.

[0072] In some embodiments of the system, the artificial respirator is set up and configured to identify the early expiration triggering from a determined respiratory flow and / or an expected respiratory flow and / or a time profile of the respiratory effort flow.

[0073] In some embodiments of the system, the artificial respirator is set up and configured to identify the early expiration triggering from a position of a start of the pressure ramp and / or an end of the pressure ramp and / or a local maximum and / or a local minimum of the determined respiratory flow and / or the expected respiratory flow and / or a value of the flow rate.

[0074] In some embodiments of the system, the artificial respirator is set up and configured to identify the early expiration triggering from at least one of the following points:

[0075] - a value of the determined respiratory flow at the start of the pressure ramp is greater than a value of the determined respiratory flow at the end of the pressure ramp

[0076] - a value of the determined respiratory flow at the start of the pressure ramp is greater than a value of q1

[0077] - a value of the determined respiratory flow at the end of the pressure ramp is smaller than a value of q2

[0078] - e determined respiratory flow (at the local maximum) / determined respiratory flow (at the end of the pressure ramp) < expected respiratory flow (maximum) / expected respiratory flow (at the end of the pressure ramp)

[0079] - f Determined respiratory flow at the end of the pressure ramp > determined respiratory flow at the local maximum

[0080] - g Determined respiratory flow at the local minimum < determined respiratory flow at the end of the pressure ramp + determined respiratory flow at the local maximum

[0081] - (h < determined respiratory flow at the local maximum - determined respiratory flow at the end of the pressure ramp) or (h < expected respiratory flow (local maximum) - determined respiratory flow at the local minimum)

[0082] - determined respiratory flow at the local minimum < q3

[0083] Here, the coefficient e is in the range from 0.5 to 2.0, preferably between 1 and 1.8; f is in the range from 0.9 to 2.9, preferably in the range from 1.7 to 2.3; g is in the range from 1 to 3, preferably between 1.8 and 2.2; h is in the range from 2 l / min to 10 l / min, preferably between 3 l / min and 7 l / min. The values of q1, q2 and q3 are, for example, independently of one another, in the range from -5 l / min to +5 l / min, preferably between -1 l / min and +1 l / min.

[0084] In some embodiments of the system, the artificial ventilator is set up and configured to identify an early exhalation trigger in accordance with the following points:

[0085] - determined respiratory flow at the beginning of the pressure ramp is greater than 0 l / min

[0086] - determined respiratory flow at the end of the pressure ramp is less than 0 l / min

[0087] - e Determined respiratory flow at the end of the pressure ramp > determined respiratory flow at the local maximum

[0088] - f Determined respiratory flow at the end of the pressure ramp > determined respiratory flow at the local maximum

[0089] - g Determined respiratory flow at the local minimum < determined respiratory flow at the end of the pressure ramp + determined respiratory flow at the local maximum

[0090] (h < determined respiratory flow (at local maximum) - determined respiratory flow (at end of pressure ramp)) or (h < expected respiratory flow (local maximum) - determined respiratory flow (at local minimum))

[0091] determined respiratory flow (at local minimum) < 0;

[0092] Here, the coefficient e is in the range of 0.5 to 2.0, preferably between 1 and 1.8; f is in the range of 0.9 to 2.9, preferably in the range of 1.7 to 2.3; g is in the range of 1 to 3, preferably between 1.8 and 2.2; h is in the range of 2 l / min to 10 l / min, preferably between 3 l / min and 7 l / min.

[0093] In some embodiments of the system, the triggering sensitivity comprises a value controlling the switching from the inspiration phase to the expiration phase, wherein the artificial respirator is set up and configured to adjust the value of the triggering sensitivity depending on the identified premature expiration trigger, which value controls the switching from the inspiration phase to the expiration phase.

[0094] In some embodiments of the system, it can be provided that the identification of asynchronies, such as missed breaths, brief trigger delays and / or premature expiration triggers, is additionally refined and / or alternatively performed by using (breathing) volume, pressure, flow and / or (breathing) frequency parameters. For example, it can be provided that features of the time curve of the pressure, the flow, the breathing frequency and / or the breathing volume are included into the identification of asynchronies.

[0095] The present invention also relates to a method for identifying asynchronies between an artificial respirator and a living being, wherein, using the lung elasticity E and the airway resistance R of the living being, asynchronies in the form of brief trigger delays and missed breaths are identified.

[0096] It is noted that features which are recited individually in the claims can be combined with each other in any technically meaningful manner and illustrate further configurations of the present invention. The description, in particular in connection with the attached drawings, additionally characterizes and specifies the present invention.

[0097] It is further noted that the conjunction "and / or", as used herein in the context of two features and connecting the two features with each other, is always to be interpreted in such a way that in a first configuration of the subject matter according to the invention only the first feature can be present, in a second configuration only the second feature can be present, and in a third configuration not only the first feature, but also the second feature can be present.

[0098] A breathing machine is to be understood as a device which supports a user or a patient in spontaneous breathing, takes over the artificial breathing of the user or patient and / or is used for respiratory therapy and / or influences the breathing of the user or patient in other ways. The breathing machine comprises, for example, but not exclusively, a CPAP device and a BiLevel device (sometimes called BiPAP), an anaesthesia device, a respiratory therapy device, a (clinical, outdoor or emergency) breathing device, a high flow therapy device and an expectoration device. A breathing machine can also be understood as a diagnostic device for artificial breathing. Here, the diagnostic device can be used in general to detect medical parameters of a patient. The breathing machine also comprises a device which can detect and optionally process medical parameters of a patient in connection with breathing or only in connection with respiration.

[0099] A patient interface is to be understood as a part of a breathing machine or a connected peripheral device which is designed to interact with a patient, in particular for therapeutic or diagnostic purposes. In particular, a patient interface is to be understood as a mask of a breathing machine or a mask connected to a breathing machine. The mask can be a full-face mask, i.e. a mask which encloses the nose and the mouth, or a nasal mask, i.e. a mask which only encloses the nose. A tracheal tube and a so-called nasal cannula can also be used as a mask.

[0100] The system of the present invention is in particular suitable for use in the field of the treatment and artificial breathing of a patient. In addition thereto, the system of the present invention is also suitable for use in other fields in which a support of spontaneous breathing can be desired, for example in the case of divers, mountain climbers, in protective equipment for firemen, etc. Furthermore, the system of the present invention and the method of the present invention can also be applied in the case of non-human beings. Thus, it is to be noted that the described embodiments are designed for humans and require adaptation of parameters, for example flow and volume parameters and time spans, for example breath lengths, if necessary in an implementation for non-human beings.

[0101] Asynchronous is to be understood as a deviation of the predefined breathing characteristics of the artificial respirator from the natural and / or intentional breathing of the living being. For example, the following situation is to be understood as asynchronous: When the living being exhibits an effort of inhalation, the artificial respirator does not recognize this effort and accordingly does not trigger support for breathing, in particular for inspiration. Asynchronous is also to be understood as follows: Although the living being does not intend to breathe, the artificial respirator recognizes a breath and accordingly triggers support or artificial respiration. In some embodiments of the present invention, the artificial respirator is so set that from time to time artificial respiration is triggered without recognizing a breathing effort of the living being. This is the case, for example, when the artificial respirator does not recognize a breathing effort of the living being for a period of time. Conversely, such forced or coerced artificial respiration is not to be understood as asynchronous. In some embodiments, further deviations, such as a phase offset (the patient exhales, but the artificial respirator recognizes an inhalation) or a time-delayed support (the artificial respirator reacts too late to a breathing effort or misses the transition from inspiration to expiration) can also be understood as asynchronous.

[0102] In the course of the present invention, a distinction can be made between at least three types of breaths: autonomous breaths, missed breaths and breaths predefined by the artificial respirator. Autonomous breaths are to be understood as breaths which are recognized by the artificial respirator and are accordingly supported by the artificial respirator at least in the inspiration phase, i.e. on inhalation. Missed breaths are breaths in which the living being exhibits a breathing effort, but this breathing effort is not recognized by the artificial respirator and therefore no support on inhalation takes place. Predefined breaths are breaths which are predefined by the artificial respirator, while the living being exhibits no breathing effort or is not recognized by the artificial respirator. Predefined breaths occur, for example, when a period of time elapses after the last recognized breath without another breath taking place.

[0103] It is to be noted that a trigger delay is determined for each triggering of the inspiration support of the artificial respirator, not only for autonomous breaths, but also for predefined breaths. For the system of the present invention, the trigger delay alone does not constitute an asynchrony, only a trigger delay which is less than a determined threshold value, i.e. a short trigger delay, is evaluated as an asynchrony. A short trigger delay is therefore to be considered interesting, since it does not occur in the case of autonomous breaths, i.e. intentional breathing of the living being, and can be related to a (coerced) triggering by the artificial respirator. That is, a strict distinction is to be made between a short trigger delay and a trigger delay (in general). In a preferred embodiment of the system, no trigger delay is determined for the triggering of inspiration by the artificial respirator in the absence of a breathing effort of the living being.

[0104] Furthermore, it should be noted that the units used, in particular the time units, are synonymous in all known writings. Thus, the unit "s" as well as the unit "sec" corresponds to seconds, and can be used in an interchangeable manner in these three forms (s, sec, seconds). The same applies to minutes, which are sometimes abbreviated as "min". It should be noted, in particular when using "min", that the unit "min" cannot be confused with the minimum function min(). In particular, where reference is made to the function min(), this function is set in the context with at least brackets, in which the properties / values / actions are respectively listed in brackets.

[0105] According to the application, the artificial respirator is at least equipped with a sensor unit, a preprocessing unit, a calculation unit, an identification unit, a control unit, and a breathing gas source, for example a blower unit / valve unit. The sensor unit, the preprocessing unit, the calculation unit, the identification unit, and the control unit have, for example, respectively individually or also jointly, a processor, so that the following steps, for example calculations, analyses, and / or algorithms, can be carried out.

[0106] The sensor unit is configured to measure measurement values, for example relating to the pressure and the flow of the living being and of the artificial respirator, for example the gas flow and the gas pressure provided by the breathing gas source. It can be provided in some embodiments that the sensor unit is also configured to measure further measurement values, for example temperature, humidity, gas concentration, volume, etc.

[0107] The preprocessing unit is provided, for example, for preprocessing the measurement values of the sensor unit and for providing them to the system.

[0108] The calculation unit is provided, for example, for further processing the preprocessed measurement values and further data, values, and information by means of a processor. In particular, the calculation unit is provided for carrying out subsequent calculation steps.

[0109] The identification unit is primarily provided for determining different states of the breathing of the living being (inspiration phase, expiration phase, etc.) from the calculated data, values, and information. In particular, the identification unit is provided for identifying an asynchrony between the artificial respirator and the living being, which asynchrony takes the form of a short breath delay, a missed breath, and in some embodiments also an erroneous triggering.

[0110] The control unit is configured to at least partially and at least temporarily automatically control the artificial respirator 1 at least in dependence on the asynchrony identified by the identification unit.

[0111] In the system of the present application, the identification of asynchronies in the form of missed breaths, short breath delays and, in some embodiments, in the form of false triggers, is based on the effective lung parameters of the living being, such as the effective airway resistance R and the effective lung elastance E. Usually, the lung parameters are determined when the living being is under anesthesia and fully passively breathing. However, since the lung parameters are fitted or derived here during artificial breathing and active breathing of the living being, the parameters are called "effective" parameters.

[0112] The effective parameters can be determined, for example, by a mathematical lung model, such as a one-compartment lung model. In some embodiments of the present application, other mathematical lung models can be used as well, such as a two-compartment lung model or a non-linear lung model.

[0113] The one-compartment lung model describes the effective lung elastance E, the effective airway resistance R, the tidal volume V, the breath flow and the base pressure P b (e.g. positive end-expiratory pressure (PEEP)) and the pressure P provided by the artificial breathing machine by the following relation:

[0114] .

[0115] The effective lung elastance E and the effective airway resistance R can be determined, for example, by the one-compartment lung model by means of a multiple linear regression. For this purpose, it is assumed that, for each individual breath, the pressure P, the base pressure P b , the tidal volume V and the breath flow are known. For this purpose, the following definitions

[0116] ,

[0117] are made, where the index describes the measurement point at different points in time. Furthermore, the following definitions

[0118]

[0119] and

[0120] ,

[0121] are made, so that the one-compartment lung model can be expressed as

[0122] .

[0123] For determining the effective lung elastance E and the effective airway resistance R, a multiple linear regression technique is applied, which leads to a system of linear equations of the following form:

[0124] .

[0125] Here, At is the transpose of A. That is, it follows that

[0126] .

[0127] The system of linear equations can be solved for E and R and yields for a specific breath an approximation of the effective airway resistance R and the effective lung elasticity E. The mean square of the residual

[0128]

[0129] can be used to determine an estimate of the accuracy of the approximation of E and R for a specific breath.

[0130] The lung parameters E and R can vary over time depending on different influences, for example the position of the living being, the sleep phase, etc. The determined values for E and R can also have different accuracies for different breaths. In order to take into account changes over time and varying accuracies, the determined lung parameters are filtered before the asynchrony is identified. For this purpose, an average or mean value can be determined by different methods, for example a weighted average.

[0131] An exponentially weighted average is determined by

[0132]

[0133] and

[0134]

[0135] wherein the index describes the number of the breath, and λ is a so-called forgetting factor which is used to weight the previous as well as the current breath in the average accordingly. Here, the forgetting factor λ is chosen for example according to a time constant

[0136]

[0137] The time constant τ is for example in the range of about 110 sec to 180 sec, corresponding to a 2 minute interval, wherein a typical breath duration Typical breath lengths can typically be assumed in the range of 2.0 sec to 6.0 sec, preferably, a breath length can for example be assumed between 3.0 sec and 4.0 sec. In some embodiments, instead of 2 minute intervals, also other interval lengths can be chosen. The length of the time interval can for example also be chosen between 1 minute and 10 minutes. Accordingly, in some embodiments, also the forgetting factor λ can be adapted, which typically has a value of 0.01 to 1.00. If for example a breath length between 3.0 sec and 4.0 sec is assumed and an interval with a length between 100 sec and 180 sec is observed, λ can be between 0.90 and 1.00, preferably between 0.95 and 0.99. For example, the forgetting factor λ is adapted to the assumed typical breath duration and the observed time interval. For the calculation, the breath duration can likewise be chosen in a variable manner and can for example be in the range of 1.0 sec to 15.0 sec, preferably between 2.0 sec and 8.0 sec.

[0138] In some embodiments of the present application, the average of R and E can also be determined by other methods, for example by a linearly weighted mean and / or a logarithmic mean and / or a quadratic mean and / or a cubic mean and / or a Gastwirth-Cohen mean and / or a different average or a combination of methods for determining a (weighted) average.

[0139] The calculation of the effective lung elastance E and the effective airway resistance R forms the basis for determining further parameters, for example the respiratory effort flow and the expected respiratory flow , which in turn identify asynchronies, for example missed breaths, trigger delays and false triggers by the artificial ventilator, if necessary.

[0140] The analysis of the respiratory flow is a basic tool for determining asynchronies between the patient and the artificial ventilator. In order to identify abnormal phenomena in the respiratory flow, it is advantageous to know how the behavior of the respiratory flow can be expected. A distinction between the determined respiratory flow and the expected respiratory flow can for example indicate an asynchrony. For a patient being artificially ventilated, the respiratory flow strongly depends on the pressure generated by the artificial ventilator. If the differential equation of the one-compartment lung model is solved by inputting the pressure P generated by the artificial ventilator and the previously determined lung parameters and

[0141] ,

[0142] then the expected flow can be determined​ Furthermore, the expected volume At the beginning of the breath is zero. Here, the determined breath flow is the breath flow of the patient which is calculated from the flow measured by the artificial breathing machine minus the leakage (by guessing / estimating or measuring) and other inaccuracies / influences.

[0143] If the determined breath flow and the expected breath flow are known, the deviation, the residual, can be determined as breath effort flow ,

[0144]

[0145] The breath effort flow contains information about the (unanticipated) breath effort of the living being. The breath effort flow and / or the time curve of the breath effort flow contains key information for the algorithm to detect asynchronies.

[0146] The system of the invention is set up to implement an algorithm for identifying asynchronies based on the analysis of the breath effort flow and further signals / data / values.

[0147] The breath effort of the patient which is missed by the artificial breathing machine and which is therefore not supported by the artificial breathing machine by increasing the pressure and / or the flow is defined as missed breath.

[0148] In the case of a missed breath, the (or also determined) breath flow of the breathing system is typically characterized by a small positive maximum value after which a small negative minimum value follows.

[0149] The identification of a missed breath is implemented, for example, by a machine learning algorithm. For this purpose, the real data of the living being in terms of missed breaths are initially manually analyzed and provided to the machine learning algorithm. The machine learning algorithm can then be applied to unknown data or during the application of the artificial breathing machine. For example, the machine learning algorithm is stored on the artificial breathing machine after teaching by the manually analyzed data and implemented by the identification unit.

[0150] It can further be considered that the machine learning algorithm makes further learning progress on the artificial ventilator and that the further learning progress is from time to time transmitted to the server (or cloud) for example (anonymously) via an interface. With this server the collected data can be used in order to improve the algorithm, for example by a higher precision in the recognition. Thus, it can be provided that the artificial ventilator updates the machine learning algorithm from time to time with the data of the server or provides further learning data. It can also be considered that the machine learning algorithm learns further from time to time outside the artificial ventilator, for example by further manually analyzed data, and that the learning progress is from time to time transmitted to the artificial ventilator so that the machine learning algorithm is further improved.

[0151] The machine learning algorithm recognizes a missed breath according to the breathing effort flow according to features, for example:

[0152] 1. The local maximum of the determined breathing flow must be located between two minima of the breathing effort flow

[0153] 2. The difference between the time position of the local maximum of the breathing effort flow and the corresponding left minimum

[0154] 3. The difference between the time position of the local maximum of the breathing effort flow and the corresponding right minimum

[0155] 4. The difference between the value of the local maximum of the breathing effort flow and the corresponding left minimum

[0156] 5. The difference between the value of the local maximum of the breathing effort flow and the corresponding right minimum

[0157] 6. The expected breathing flow at the time point of the local maximum of the breathing effort flow

[0158] 7. The time between the maximum of the breathing effort flow and the expected triggering time point.

[0159] If at least one of the features is recognized, the algorithm can conclude a missed breath. It is preferably provided that a plurality of the mentioned features, for example two or four or all features, must apply in order for the algorithm to conclude a missed breath.

[0160] The expected triggering time point By the length of the last autonomous breath triggered by the organism itself and the last expected triggering time

[0161] ,

[0162] wherein γ is a weighting factor for the and​ The coefficient γ. Here, the value of γ can be chosen between 0.01 and 1.00, preferably between 0.1 and 0.5. For example, values of 1 / 4 and / or 1 / 3 and / or 1 / 2 for γ can be considered as meaningful. In some embodiments, the expected trigger point in time can also be determined by a fixed value. In some embodiments, the trigger point in time is determined by a sliding average, for example, over an interval corresponding to a time period between 3 breaths and 100 breaths. Here, also other methods for determining an average or mean value can be used.

[0163] Further, the artificial ventilator is set up for identifying asynchronies according to a trigger delay or a short trigger delay.

[0164] The trigger delay occurs at the beginning of the spontaneous breath or at the beginning of the breathing effort and is defined as the time span between the activation of the patient's respiratory muscles and the triggering of the breathing support by the artificial ventilator. Typically, the trigger delay is characterized by a local maximum of the breathing effort flow. Alternatively or additionally, the trigger delay is characterized by the distance of the maximum in the breathing effort and the trigger point in time of the artificial ventilator.

[0165] The trigger delay is determined for all triggered breaths. If the trigger delay is smaller or equal to a threshold value (e.g. 0.1 s), which is typically too short for a spontaneous breath, the trigger delay is called "short trigger delay". While the trigger delay is determined for all breaths (spontaneous and pre-given by the artificial ventilator), the analysis of the short trigger delay is only performed for spontaneous, i.e. not pre-given by the artificial ventilator, breaths. The determination of the trigger delay is, for example, performed in the following way:

[0166] First, the breathing effort flow is filtered by a low pass filter with a limit frequency of 3 Hz, e.g. a Butterworth filter (e.g. first, second, third, fourth and / or fifth order) and / or a Legendre filter and / or a Techebyscheff filter and / or a Bessel filter and / or a Cauer filter and / or a Gauβ filter and / or a Raised-Cosine filter and / or a TBT filter, in order to obtain

[0167] Subsequently, the expected amplitude A is calculated for the current breath i,

[0168] ,

[0169] wherein P set ​It is the pressure setpoint, t i It is the starting point of breathing i. IPAP is the positive inspiratory airway pressure (IPAP).

[0170] Starting directly before the inspiratory trigger point and moving backward into the expiratory phase, check if each measurement point k is part of the trigger delay. First, calculate the number n of measurement points k with relatively high respiratory flow rates exceeding a threshold. highFlow :

[0171]

[0172] Where a1 is between 0.025 and 0.075, for example, between 0.050 and 0.060.

[0173] Then, starting from the last measurement point greater than the threshold, the backtracking process continues, where the number of measurement points n is as follows: increasingFlow Counting: The measurement points are characterized in that they have increasing respiratory effort flow and each measurement point k satisfies the following condition:

[0174] and

[0175] and

[0176] or

[0177] ,

[0178] Here, a2 is selected to be between 0.3 and 0.6, for example, 0.4 or 0.5. The total number of test points corresponding to the possible trigger delays is:

[0179] .

[0180] Finally, check if the possible trigger delay is valid. For example, if

[0181] and

[0182] and

[0183] ,

[0184] Where a3 is between 0.05 / s and 0.50 / s, preferably between 0.20 / s and 0.30 / s, and k startAs a first point of measurement for the possible trigger delay, it is the case that if the possible trigger delay is not valid, n is set to 0 (zero). Then, the trigger delay is derived as:

[0185] .

[0186] That is, in the case of spontaneous breathing, an invalid trigger delay is evaluated in correspondence with a short trigger delay. As described above, a trigger delay t triggerDelay which is less than or equal to a determined threshold value is evaluated as a short trigger delay by the artificial ventilator. For the threshold value, a value can be set, for example, between 0.01 sec and 0.5 sec, preferably between 0.05 sec and 0.15 sec.

[0187] In some embodiments, the artificial ventilator is furthermore set up to identify false triggers on the basis of an analysis process / computation as follows:

[0188] A false trigger is to be understood as a trigger which is identified by the artificial ventilator, but which is not required by the patient, i.e. the patient does not show a breathing effort. The false trigger can be identified by analyzing the data in a time period around the trigger time point t trig of the ventilator. The normalized breathing flow before the trigger

[0189]

[0190] is calculated in a time period before t trig , wherein t pre of between 0.08 sec and 0.2 sec is expected. The normalized breathing flow after the trigger

[0191]

[0192] is calculated from a time period after t trig , wherein a value of between 0.1 s and 0.5 s can be expected for t post . A false trigger of the artificial ventilator is identified, for example, when f pre is less than a value of between 0.01 and 0.10, for example less than 0.05, and f post is less than a value of between 0.5 and 0.9, for example less than 0.7.

[0193] The system is furthermore set up and configured, for example, to use the identified short trigger delay and the missed breaths in order to automatically set the trigger sensitivity of the artificial ventilator. The automatic trigger setting automatically adapts the sensitivity of the artificial ventilator for triggering to the inhalation in order to meet the individual requirements of the patient.

[0194] In general, the setting of the triggering sensitivity is carried out by designating a level. In some embodiments, the levels of the triggering sensitivity can be reproduced in terms of breathing flow values, for example in 1 / min. Thus, for example, a graduation from 1 1 / min to 15 1 / min in steps of 1 1 / min can be considered. In addition thereto, intermediate levels can also be introduced, for example in steps of 0.5 1 / min. Other designations for the levels of the triggering sensitivity, for example by means of numbers, letters, descriptions and / or symbols, are also possible. The descriptions can for example take the form of "very sensitive, sensitive, less sensitive, not sensitive". In addition to the designation of the levels (numerical, alphabetical, symbolic, by flow values, etc.), the number and / or the spacing of the levels available for use can also be varied.

[0195] In some embodiments of the system, the triggering sensitivity can be set, for example manually, to a level between 1 and 8, wherein for example smaller values correspond to higher sensitivity, for example in connection with smaller breathing flows which trigger the support by the artificial respirator. For an automatic setting of the triggering, for example an additional level 0 is added to the triggering sensitivity, which corresponds to an even higher sensitivity. This higher sensitivity can be particularly useful for COPD patients with intrinsic positive end-expiratory pressure (iPEEP), but can also be useful for other pathologies or in situations in which the system or the artificial respirator of the application is used. The automatic setting of the triggering is designed in such a way that thereby the sensitivity level is set between 0 and 3. In some embodiments, the triggering sensitivity can also be set between 0 and 8 by the automatic setting of the triggering. In application areas outside of artificial respiration therapy, a too high sensitivity (corresponding to small levels of the triggering sensitivity) can possibly be considered undesirable or disruptive. The levels mainly reproduce thresholds for breathing flows at which the triggering of an inspiration or support in the case of an inspiration takes place.

[0196] The adaptation of the triggering sensitivity by automatic setting (also referred to as automatic triggering function) is based on the number of missed breaths and short triggering delays determined in a predetermined time interval, for example two minutes, in which other time intervals can also be used, which are adapted in a desirable manner to the time interval of the calculation or to the time interval of the recognition of asynchronies. The following mutually exclusive rules apply to the adaptation of the triggering sensitivity

[0197] 1.

[0198]

[0199] 2.

[0200]

[0201] 3.

[0202] wherein #IneffEff denotes the number of missed breaths registered in the time interval, #ShortTrigDel represents the number of short trigger delays in the same interval, the index "old" describes the previous time interval, the parameters b, c, d are for example in the range of

[0203]

[0204]

[0205]

[0206] trigSens is the current trigger sensitivity level. In particular, the parameters b, c, d can take values from 0 to 6, for example from 0 to 4 or from 0 to 3. Here, it can be provided that b = c and c > d apply. Here, the parameter d has for example a value less than 1. In this case, the comma separates the two parameters of the minimum function min() and the maximum function max(). min(i,j) and max(i,j) are functions. Here, min() will return the smaller value of i and j, while max() will have the larger value as a result. Example: min(2,4) = 2 and max(2,4) = 4. Accordingly, trigSens = min(trigSens + 1,4) means that the variable trigSens is increased by 1, but can take a maximum value of 4. Example: trigSens has the value 3. After the assignment trigSens = min(trigSens + 1,4) is carried out, trigSens has the new value min(4,4) = 4. If trigSens now has the value 4 and the assignment trigSens = min(trigSens + 1,4) is carried out, trigSens has the new value min(5,4) = 4. That is, TrigSens can in this way become not greater than 4.

[0207] Instead of numerical values for TrigSens, as shown before, other expressions are also possible, for example words, letters and / or symbols. If numerical values are not used for TrigSens, the adaptation procedure must be adapted accordingly, so that a corresponding level adaptation can be carried out. Additionally or alternatively, it is also provided that the trigger sensitivity is displayed by means of letters, symbols, descriptions and / or flow values, wherein the respective display type is assigned a respective numerical scale.

[0208] ​​In some embodiments, b, c, d can also take other values, for example values between 1 and 6, preferably between 2 and 4. In some embodiments, the value ranges indicated here for b, c, d can also be mixed with the above-mentioned value ranges. For example, for b, c, a value range of 1 to 6 can apply, while for d, a value range of 0 to 6 applies. Furthermore, it can be considered, for example, that the entire preceding interval is described by 2-minute intervals, and that after the end of the preceding interval, the next interval begins. That is, the first interval begins, for example, at second 0 and lasts until second 120. The second interval seamlessly follows on and lasts from second 120 until second 240. In addition thereto, the selected interval length can lie in the range between 60 sec and 240 sec, preferably between 100 sec and 180 sec.

[0209] For cases with high leak flow, the number of missed breaths and the number of short trigger delays become less accurate. Therefore, if the average leak flow in a 2-minute interval is greater than a value between 15 l / min and 50 l / min, for example greater than 25 l / min, the trigger sensitivity is set to the following average trigger sensitivity:

[0210]

[0211] This average trigger sensitivity is calculated from the preceding time period with lower or small leak flow. Here, and are the new (index new) and old (index old) average values, is the trigger sensitivity calculated for the current time period, λ Leak is the associated forgetting factor, which can be assigned a value between 0.01 and 1.00, for example. Preferably, the value lies between 0.05 and 0.40 and / or between 0.15 and 0.30. The forgetting factor is a factor that is taken into account in order to weight the preceding and the current time period according to the 2-minute interval, or it defines the time scale of the filtering - here approximately two minutes. In some embodiments, it is determined, for example depending on the leak flow, whether and / or to what extent an adaptation of the trigger sensitivity is carried out. For example, in the case of a greater than determined leak flow, the adaptation of the trigger sensitivity is suspended. The adaptation is suspended in the case of a greater than leak flow threshold value, for example in the range between 15 l / min and 50 l / min, preferably between 20 l / min and 30 l / min. The threshold value can refer, for example, to the average value of the leak flow as well, so that the adaptation of the trigger sensitivity The adaptation of the pause can also be made from and / or in the case of a following threshold value of the average leak flow which is between 15 l / min and 50 l / min, preferably between 20 l / min and 30 l / min. For example, the triggering sensitivity is not adapted for phases with a high average leak flow of more than 25 l / min .

[0212] In some embodiments, the system is also set up to identify early exhalation triggers, so-called "early cyclings", and to evaluate them as asynchronous. An early exhalation trigger (early cycling) occurs when the artificial respirator switches from inspiration to expiration, although the user / patient has not yet finished the inspiration phase. Due to the pressure drop, the patient exhales, after which a short rise in respiratory flow typically follows, because the patient has not yet finished his inspiration or wants to continue inhaling. Usually, the patient finally adapts to the artificial respirator and starts to exhale.

[0213] In the case of a determination of an early exhalation trigger, four essential points in the respiratory flow curve need to be noted: the start of the pressure ramp (by the artificial respirator) from inspiration to expiration, the end of the pressure ramp, the position of the local maximum of the respiratory flow, which should not be located further than a determined time span after the end of the pressure ramp, and the local minimum, which should follow after the end of the pressure ramp within a determined time span. The time span for the local maximum after the end of the pressure ramp is for example between 0.1 s and 2 s, for example between 0.3 s and 0.4 s. The time span for the local minimum after the end of the pressure ramp is for example between 0.2 s and 3 s, for example between 0.5 s and 0.7 s. The early exhalation trigger can be observed at the beginning of the expiration phase and is characterized by a local maximum of the determined respiratory flow, which cannot be observed in the case of an expected respiratory flow. Accordingly, the respiratory effort flow reappearance is a local maximum after the time of the early exhalation trigger. Alternatively or in addition, instead of a pressure ramp, a flow ramp can also be used or observed.

[0214] For example, an early exhalation trigger is detected when at least one of the following conditions applies:

[0215] 1. determined respiratory flow (start of the pressure ramp) > 0

[0216] 2. determined respiratory flow (end of the pressure ramp) < 0

[0217] 3. e determined respiratory flow (local maximum) / determined respiratory flow (end of pressure ramp) < expected respiratory flow (maximum) / expected respiratory flow (end of pressure ramp)

[0218] 4. f determined respiratory flow (local maximum) > determined respiratory flow (end of pressure ramp)

[0219] 5. g determined respiratory flow (local minimum) < determined respiratory flow (end of pressure ramp) + determined respiratory flow (local maximum)

[0220] 6. (h < determined respiratory flow (local maximum) - determined respiratory flow (end of pressure ramp)) or (h < expected respiratory flow (local maximum) - determined respiratory flow (local minimum))

[0221] 7. determined respiratory flow (local minimum) < 0

[0222] Here, the coefficient e is in the range of 0.5 to 2.0, preferably between 1 and 1.8; f is in the range of 0.9 to 2.9, preferably in the range of 1.7 to 2.3; g is in the range of 1 to 3, preferably between 1.8 and 2.2; h is in the range of 2 l / min to 10 l / min, preferably between 3 l / min and 7 l / min.

[0223] In some embodiments, in order to identify an early expiration trigger, it can also be provided, instead of conditions 1 and 2, that in general the determined respiratory flow at the beginning of the pressure ramp is greater than the determined respiratory flow at the end of the pressure ramp. In some embodiments, the threshold values for conditions 1, 2 and 7 can also be greater than and / or less than 0 (l / min) independently of one another.

[0224] In some embodiments, it is provided that, in order to identify an early expiration trigger, at least 2 or 4 or more or all of the mentioned conditions must apply.

[0225] It is noted that the asynchronies can be identified jointly from the respiratory flow or respiratory effort flow. The described identification possibilities can be combined accordingly, which are described exemplarily individually. The following description according to the figures is also partly respectively an identification of individual asynchronies. The combination of the described identifications can also be implemented in order to identify, for example, a missed breath and / or a short trigger delay and / or a false trigger and / or an early expiration trigger at the same time. Accordingly, the trigger sensitivity can also be controlled at least partly on the basis of the jointly identified asynchronies.

[0226] In some embodiments, the triggering sensitivity comprises at least one value for switching the artificial respirator into an inhalation phase, at which value the inhalation of the user is supported, and optionally at least one value for switching into an exhalation phase, which supports the user in the exhalation. The exhalation phase differs from the inhalation phase, for example, in that a lower pressure and / or a smaller flow is predefined by the artificial respirator. BRIEF DESCRIPTION OF DRAWINGS

[0227] In the following, the application is explained with respect to exemplary embodiments Figures 1 to 7 The application is explained in more detail. DETAILED DESCRIPTION

[0228] In Figure 1 In the exemplary illustration, an artificial respirator 1 is shown, which has a sensor unit 11, a preprocessing unit 12, a calculation unit 13, an identification unit 14, a memory unit 15, a monitoring unit 16, a control unit 17 and a blower unit / valve unit 18. The units 11, 12, 13, 14, 16, 17 can be, for example, part of a computer program, which is implemented by a processor on the artificial respirator 1. It is also conceivable to pool the units 11, 12, 13, 14, 16, 17 in a control unit, for example.

[0229] The sensor unit 11 is set up to detect measurement values, in particular parameters, which are related to the respiratory flow, the respiratory volume, the respiratory frequency, the inhalation duration and the exhalation duration, the respiratory profile, the leak or the treatment pressure. Optionally, the sensor unit 11 can make additional measurements of the composition or the temperature of the respiratory gas or of the blood. The sensor unit 11 transmits the detected measurement values to the preprocessing unit 30.

[0230] The preprocessing unit 12 can preprocess the detected measurement values. For example, the preprocessing unit 12 can perform a smoothing, an artifact removal or a down-sampling of the measurement values.

[0231] The calculation unit 13 calculates signals and / or characteristic quantities, for example mean values, median values, percentile values, derivatives, frequency distributions, durations or shares above or below threshold values, from the measurement values detected by the sensor unit 11 and preprocessed by the preprocessing unit 12.

[0232] The identification unit 14 is set up to identify events / states, for example alarms, respiratory pauses, artifacts, coughing episodes, oxygen (un)saturation, asynchronies 2 between the device and the user, missed breaths 218, triggering delays 305, false triggering 307, inhalations, exhalations and / or forced breaths.

[0233] The memory unit 15 mainly stores or at least buffers values / parameters detected by the sensor unit 11 and / or values, data and / or information pre-processed by the pre-processing unit 12 and / or the calculation unit 13. Information, data and values obtained by the recognition unit 14 can also be at least buffered in and / or at least buffered in the memory unit. Buffering means, for example, that values, data and / or information are stored until transmission and then, for example, deleted or released for re-writing.

[0234] The monitoring unit 16 detects technical problems of the artificial respirator 1, for example. Technical problems can be, for example, a low battery status, a fault in an electronic device, a damaged battery, a damaged component, a current interruption, an incorrectly working fitting, an untrustworthy measurement value or a departure from an allowed temperature range. The monitoring unit 17 can display or transmit an alarm on the artificial respirator 1 via an interface in the event of a recognized technical problem.

[0235] The control unit 17 is used, for example, to control the artificial respirator 1, in particular to control the blower unit and / or the valve unit 18 to generate a breathing gas flow or an artificial respiration pressure. The control unit 17 can also be configured to control further components and / or units of the artificial respirator 1. In some embodiments, the control unit 17 can also be further divided and can consist of a plurality of control units, which each control individual units and / or components of the artificial respirator 1. In particular, the control unit 17 is set up to at least partially automatically control the artificial respirator 1 on the basis of data, values and knowledge obtained by the sensor unit 11, the pre-processing unit 12, the calculation unit 13 and / or the recognition unit 14. In some embodiments, the control unit 17 is set up in such a way that the control is carried out partly on the basis of manually set parameters and partly on the basis of automatically set parameters. In some embodiments, the control can also be carried out only manually or only automatically.

[0236] The artificial respirator 1 is set up, for example, to pre-specify a constant breathing gas pressure (for example in the form of a CPAP therapy) and / or to switch a pre-specified breathing gas pressure between an exhalation phase and an inhalation phase (for example in the form of a Bi-Level-Beatmungsgerät). The pre-specified breathing gas pressure during the inhalation phase, for example, is higher than the pre-specified breathing gas pressure during the exhalation phase. In some embodiments, the switching between inhalation and exhalation and / or between exhalation and inhalation takes place in the form of a pressure ramp, so that the pressure pre- specification and / or the flow pre-specification is not changed abruptly. Instead of by a pressure ramp, the switching can also take place in the form of a flow ramp. The point at which the switching between inhalation and exhalation or between exhalation and inhalation takes place can be determined, for example, at least partially by a trigger sensitivity.

[0237] The identification unit 14 is configured, for example, to identify asynchrony 2 between the ventilator 1 and the connected organism. For example, asynchrony 2 exists when the organism wants to inhale, but the ventilator 1 fails to recognize this and does not trigger support during the inspiratory phase. Conversely, if the organism does not want to inhale, but the ventilator 1 incorrectly recognizes the organism's effort to inhale and triggers inspiratory support accordingly, this can also be considered asynchrony 2. Planned, forced inhalation triggered by the ventilator 1, for example because the organism has exceeded a certain time since its last inhalation or has exceeded the maximum pre-defined exhalation time, is not evaluated as asynchrony 2 in most embodiments. Therefore, data and values ​​measured and / or obtained during forced inhalation are generally not used to evaluate asynchrony 2.

[0238] For example, during the use of a ventilator 1, an asynchronous 2 is identified. Accordingly, the result of the identification is generated directly "in real time" and, if necessary, is also directly used by the ventilator 1 for control purposes.

[0239] Here, the system is Figures 1 to 3 In exemplary embodiments, a missed breath 218, i.e., an event in which the organism intends to inhale but the ventilator 1 does not trigger inspiratory support, is identified as asynchronous 2. A brief trigger delay 308, i.e., an event in which the organism does not intend to inhale but the ventilator 1 has triggered inspiratory support, is also identified as asynchronous 2. Here, a trigger delay 305 determined to be equal to or less than, for example, 0.1 sec is referred to as a brief trigger delay 308. In the case of a brief trigger delay 308, it is assumed that the organism does not intend to inhale. In some embodiments, the system is also configured such that asynchronous 2 in the form of an erroneous trigger 307 is identified. While the brief trigger delay 308 can be considered a cue for triggering when the organism does not intend to inhale, the system identifies the erroneous trigger 307 with greater reliability.

[0240] The identification unit 14 identifies transient trigger delays 308 and missed breaths 218 from the respiratory effort flow, expected respiratory flow, and determined respiratory flow. Here, the determined respiratory flow is the patient's respiratory flow calculated from the flow measured by the ventilator, minus leakage (by guess / estimation or measurement) and other inaccuracies / influences. The calculation (which forms the basis for the identification of asynchronous 2 by the identification unit 14) is performed, for example, by the calculation unit 13. The expected respiratory flow is determined by effective airway resistance. R and effective lung elasticity Edetermined. The effective airway resistance and the effective lung elasticity are in turn calculated by a mathematical lung model, for example a single-compartment lung model. The corresponding parameters R and E may be determined, for example by multiple linear regression, from the lung model used.

[0241] In Figure 2 and Figure 3 the recognition of an asynchronous 2 in the form of a missed breath 218 is shown schematically. In Figure 2 the time curves of the determined respiratory flow 203 and the expected respiratory flow 204 are plotted schematically in a graph, which has the time 202 as x-axis and the flow rate 201 on the y-axis. The duration of the breath corresponds to a time section 208, in which the breath can be roughly divided into inspiration and expiration. The inspiration can be identified substantially by positive respiratory flow. The expiration is marked substantially by negative respiratory flow, wherein the respiratory flow becomes smaller at the end of expiration - i.e. in the direction of positive values, but is still negative, and finally approaches the zero value with a flatter slope. In Figure 2 the graph of the two complete breaths 216, 217 are shown, for example can be identified by not only the positive and negative peaks of the determined respiratory flow 203, but also of the expected respiratory flow. In addition, a missed breath 218 is also shown exemplarily. The missed breath 218 can be identified, for example, by the fact that not only the positive, but also the negative peaks of the determined respiratory flow 203 have values that are significantly smaller than the values of the complete breath 216. The support by the artificial breathing machine 1 is not triggered, which can be seen, for example, by the expected respiratory flow 204 in Figure 2 .

[0242] The recognition unit 14 reliably identifies the missed breath 218 from the respiratory effort flow 209, which is plotted in the graph in Figure 3 . Alternatively or additionally, it can be provided that the missed breath 218 can also be identified from features of the respiratory flow and / or the pressure and / or the respiratory frequency and / or the respiratory volume. In this graph, the flow rate 201 of the respiratory effort flow (y-axis) is plotted against the time 202 (x-axis). The recognition unit 14 checks, for example, the following features from the values of the respiratory effort flow 209, the time curve of the respiratory effort flow 209, the determined respiratory flow 203, the expected respiratory flow 204 and the expected triggering point in time in order to identify the missed breath 218:

[0243] 1. The local maximum 206 of the determined respiratory flow 204 must lie between two minima 214, 215 of the respiratory effort flow 209.

[0244] 2. The difference 210 between the time position of the local maximum 219 of the respiratory effort flow and the time position of the corresponding left minimum 214.

[0245] 3. The difference 211 between the time position of the local maximum 219 of the respiratory effort flow and the time position of the corresponding right minimum 215.

[0246] 4. The difference 212 between the value of the local maximum 219 of the respiratory effort flow and the value of the corresponding left minimum 214.

[0247] 5. The difference 213 between the value of the local maximum 219 of the respiratory effort flow and the value of the corresponding right minimum 215.

[0248] 6. The expected respiratory flow 207 at the time point of the local maximum 219 of the respiratory effort flow 209

[0249] 7. The time between the local maximum 219 of the respiratory effort flow and the expected triggering time point 205.

[0250] For example, the recognition unit 14 is set up such that the features are checked according to a machine learning algorithm. For example, for this purpose a plurality of data of the living being are analyzed and provided to a machine learning algorithm, which derives values, data, parameters and information from this, by means of which the missed breath 218 is recognized. For example, for this purpose a machine learning algorithm based on the AdaBoost Ml technique can be used.

[0251] In this way, the recognition unit 14 recognizes, for example, from at least one of the features that a missed breath is present. It is provided in some embodiments that a plurality of the features, for example at least two, four or all of the features, must be used or a criterion must be met in order to recognize a missed breath, in order for the respective feature to indicate a missed breath.

[0252] It is provided in some embodiments that the recognition of the missed breath is performed alternatively or additionally and / or further refined by using further parameters, for example pressure, flow, volume, frequency.

[0253] Furthermore, the recognition unit 14 is exemplarily also set up to recognize or determine the triggering delay 305 and to evaluate the brief triggering delay 308 as an asynchrony 2 between the artificial respirator 1 and the living being. For example, the triggering delay 305 is determined for all breaths with inspiratory support, for example the checking of the brief triggering delay 308 is performed only for spontaneous breaths. Exemplarily, the triggering delay 305 is shown in Figure 4 and Figure 5 Figure 4 ​A graph is shown in which the flow rate 301 of the determined respiratory flow 303 and the expected respiratory flow 304 are plotted against time 302. Defined as the trigger delay 305 is the time span between the activation of the respiratory system muscles of the living being and the triggering of the respiratory support by the artificial breathing machine 1, for example for inhalation. In Figure 4 , the trigger delay 305 can be identified, for example, by a misalignment between the onset of the slope of the flow rate of the determined respiratory flow 303 and the expected flow rate 304. If the flow rate 301 of the respiratory effort flow 305 is plotted against time 302, as can be seen in the graph in Figure 5 , the trigger delay 305 can be identified by the local maximum of the breath 309.

[0254] The trigger delay 305 is identified as a short trigger delay 308 if its value is not greater than a threshold value of, for example, 0.1 sec. In some embodiments, the threshold value can also be chosen to be greater, for example, up to 0.5 sec, or to be smaller, for example, 0.05 sec.

[0255] The trigger delay 305 is determined, for example, by calculation and by an algorithm using the respiratory effort flow 306. To this end, a low-pass filter with a limiting frequency of 3 Hz, here for example a third-order Butterworth filter, is applied to the respiratory effort flow 306. Furthermore, using the respiratory effort flow 306, the expected amplitude A is calculated for the current breath i. For each measurement point k, which is directly before the trigger point of inhalation and retreats into the exhalation phase, it is checked whether this measurement point k is part of the trigger delay, i.e. whether it lies between the onset of the respiratory effort of the living being and the triggering of the artificial breathing machine 1. The measurement point k corresponds, for example, to a measurement value recorded at a point in time by the sensor unit 11, which is further processed by the pre-processing unit 12 and the calculation unit 13, if necessary. The measurement point k is checked in terms of the respiratory flow as to whether it reaches or is greater than a determined threshold value, for example a1 times the expected amplitude A, and the number n highFlow of measurement points is counted, which are characterized by an increasing respiratory effort flow 306 and which satisfy a further condition. The coefficient a1 can assume a value, for example, between 0.005 and 0.1, preferably between 0.025 and 0.075. In some embodiments, the coefficient a1 is determined to have a value between 0.05 and 0.06.

[0256] From the last measurement point lying above the threshold value, looking back in time, the number n increasingFlow of measurement points is counted, which are characterized by an increasing respiratory effort flow 306 and which satisfy a further condition. The total number of measurement points of possible trigger delays 305 corresponds to n highFlow and n increaisngFlowis formed and n. Furthermore, finally, it is checked according to the measurement point k whether the calculation of the triggering delay 305 is valid (gültig or valide). If the calculation of the triggering delay 305 is not valid, the summand n is set to 0. The length t triggerDelay is obtained by multiplication of the summand n with the coefficient t tD . The coefficient t tD is for example between 0.001 sec and 0.05 sec, preferably between 0.005 sec and 0.015 sec. If t triggerDelay has a value of for example 0.1 sec or less, the ventilator 1 recognizes by means of the recognition unit 14 a short triggering delay 308 which is evaluated as an asynchrony 2.

[0257] In some exemplary embodiments, the ventilator 1 with the recognition unit 14 is set up in such a way that a false triggering 307 can be recognized and identified as an asynchrony 2. For this purpose, the data and measurement values around the triggering time point t trig of the ventilator 1 are analyzed. For this purpose, the standardized breath flow before the triggering (f pre ) and the standardized breath flow after the triggering (f post ) are calculated. If the values of f pre and f post are greater than a determined, individual threshold value, a correct triggering is recognized. If f pre and f post are below or reach these values, a false triggering 307 is recognized. The threshold value for f pre is for example determined in the range of 0.005 to 0.5, preferably between 0.025 and 0.075. The threshold value for f post is for example determined as a value between 0.1 and 1.5, preferably between 0.5 and 1.0. For example, a false triggering 307 is recognized when f pre ≤ 0.075 and f post ≤ 0.8 apply.

[0258] According to the identified asynchrony 2, the ventilator 1 can automatically adjust the triggering sensitivity 3. In some embodiments, in addition to different manual levels for the triggering sensitivity 3, the option for automatic adjustment of the triggering sensitivity 3 can also be selected. For example, on the ventilator 1, a level from 1 to 8 can be selected for the triggering sensitivity 3 or the automatic triggering sensitivity 4 can be selected. The triggering sensitivity 3, for example, reproduces the sensitivity with which the ventilator 1 triggers the inhalation support in abstract or unitless numbers. For example, with the triggering sensitivity 3, at least one threshold value of the respiratory flow rate is taken into account, at which the inhalation support by the ventilator 1 is triggered. In some exemplary embodiments, the triggering sensitivity 3 depends mainly and / or only on the threshold value of the respiratory flow rate. A higher level of the triggering sensitivity 3, for example, mainly means a higher threshold value of the respiratory flow rate, at which the inhalation support is triggered. That is, for example, level 1 is a more sensitive triggering sensitivity 3 than level 2.

[0259] The triggering sensitivity 3 can be adjusted or selected, for example, by a user interface, for example, a display device and / or an input device implemented as a touchscreen on the ventilator 1. It is also possible to adjust / select the triggering sensitivity 3 by a remote station (Gegenstelle) that is spatially separate from the ventilator 1.

[0260] If the automatic adjustment of the triggering sensitivity 3 is selected, the ventilator 1 automatically adjusts the triggering sensitivity 3 and takes into account at least the identified asynchrony 2, for example, the missed breath 218 and the short triggering delay 308. In some embodiments, in the case of the automatic adjustment of the triggering sensitivity 3, the ventilator 1 additionally also takes into account the identified false triggering 307. The ventilator 1 can automatically adjust the triggering sensitivity 3, for example, to levels 0 to 3. Here, level 0 is a more sensitive triggering sensitivity 3 than level 1. Level 0, for example, is only available for automatic adjustment, i.e., it cannot be adjusted manually. However, it can also be considered that all levels are available for both the manual adjustment of the triggering sensitivity 3 and the automatic adjustment of the triggering sensitivity 3, i.e., level 0 to 8 can be adjusted not only manually but also automatically. In addition to the division into levels 0 to 8, the triggering sensitivity 3 can also be divided into another, arbitrary number of levels. The levels can be marked, for example, by numbers, letters, or also by descriptions, for example, "very sensitive, sensitive, less sensitive, not sensitive". In some embodiments, the levels of the triggering sensitivity 3 are indicated by means of flow values, for example, in l / min. In this way, the triggering sensitivity 3 can be adjustable, for example, between 1 l / min and 25 l / min or 1 l / min and 10 l / min.

[0261] The trigger sensitivity 3 is for example reproduced by a parameter trigSens. In case of a manual setting of the trigger sensitivity 3, this parameter is changed, for example directly by an input via an interface, for example a user interface, which is not shown in the figure. In case of an automatic setting, the parameter trigSens is determined depending on the number of short trigger delays 308 and missed breaths 218 in the current time interval and the last time interval. In the exemplary embodiment shown, the time interval is a 2 minute interval. This time interval is for example adapted to the preceding time interval for determining and / or identifying an asynchrony 2. Here, the value of the parameter trigSens corresponds to the level of the trigger sensitivity 3. Figure 1

[0262] The trigger sensitivity 3 is set by a minimum function min(i,j) and / or a maximum function max(i,j). The min() function here again provides the smaller value of i and j, i.e. min(3,4) is 3. Inversely, the max() function provides the larger value of i and j, i.e. max(1,4) is 4.

[0263] A rule set is formulated, according to which the trigger sensitivity 3 is adapted. For example the following three rules, which are mutually exclusive:

[0264] 1.

[0265]

[0266] 2.

[0267]

[0268] 3.

[0269] Here, #ShortTrigDel corresponds to the number of short trigger delays 308 registered during the current time interval, #IneffEff corresponds to the number of missed breaths 218 registered, and trigSens is the current value or level of the trigger sensitivity 3. Furthermore, the index old indicates the value of the preceding time interval. Here, b, c and d are parameters in the range of 0 to 6, for example in the range of 0 to 3. In some embodiments, the parameters b, c, d can be assigned values of for example 0 to 2, wherein b and c can have the same value and d has a smaller value, for example below 1.

[0270] ​In some embodiments, b, c and d can also take other values, but it should be noted here that the three rules described above continue to exclude each other, i.e. only one rule is always fulfilled or only one rule becomes active. In some embodiments, the third rule can also be modified such that, as long as no asynchronous 2 is registered, the trigger sensitivity 3 (trigSens) is not changed, regardless of which level is currently set for the trigger sensitivity 3.

[0271] The value trigSens is changed in accordance with the minimum function min() or the maximum function max(). In this way, it is achieved by using the minimum function and the maximum function that, depending on the fulfillment of the rules, a value cannot be greater than and / or lower than a determined value. In this example, the smallest possible level of 0 has already been used. If, in another embodiment of the ventilator 1, a more sensitive level of, for example, -1 is defined below 0 for the trigger sensitivity, this level can be made available for automatic setting by the second rule.

[0272] In addition to the rules shown, it is also possible to define further rules in accordance with which the ventilator 1 can automatically set the trigger sensitivity 3. It should also be noted here that the rules defined exclude each other. In some embodiments, the ventilator 1 or the recognition unit 14 provides for recognizing false triggers 307. In accordance with this, the existing rules can be expanded by the false triggers 307 recognized. For example, additional rules can also be defined which take the false triggers 307 into account. For example, the additional rules can also be formulated such that the fulfillment of one of the first three rules does not exclude the fulfillment of at least one of the rules which take the false triggers 307 into account. That is, in addition to one of the first three rules, at least one of the further rules can also be fulfilled.

[0273] In some embodiments, for example, it is considered that the recognition of the asynchronous 2 becomes less accurate when the leakage flow, for example, rises above a value of between 15 l / min and 50 l / min, for example 25 l / min. If a leakage flow of 25 l / min or more is detected by the ventilator 1 for a time interval, for example a 2-minute interval, the ventilator 1 provides for setting the average trigger sensitivity for the next time interval and / or the current time interval from the average trigger sensitivity of the previous time interval

[0274]

[0275] Here, the coefficient λ leakdenotes a forgetting factor which weights the value of the old average trigger sensitivity with respect to the current trigger sensitivity T. For example, λ is assigned a value between 0.01 and 0.9, preferably between 0.1 and 0.5. For example, in this exemplary embodiment, λ is assigned the value 0.2. leak For example, λ is assigned a value between 0.01 and 0.9, preferably between 0.1 and 0.5. For example, in this exemplary embodiment, λ is assigned the value 0.2. leak In some embodiments, the average trigger sensitivity is not further adapted during a sustained phase with a high leak flow greater than a threshold value, for example 25 l / min. This means that the average trigger sensitivity is recalculated once after a first time interval of high leak flow greater than 25 l / min, for example 2 minutes, and then remains constant as if no time interval with a leak flow smaller than 25 l / min was registered.

[0276] In some embodiments of the system, during the use time, with the manually set trigger sensitivity 3, an asynchronous recognition is performed and a summary about the recognized asynchronies 2 is created after the end of the use. For example, the summary can also contain a suggestion for the manual setting of the trigger sensitivity 3. The suggestion can be output or displayed, for example, on a display (display screen) of the artificial respirator 1 or via an interface for remote monitoring.

[0277] Furthermore, an alarm can also be generated by the artificial respirator 1 if a threshold value of the short trigger delay 308 and / or the false triggers 307 greater than the recognized missed breaths 218 is exceeded. For example, the threshold value can be a percentage share of the total recognized breaths per time interval. Here, the time interval can be chosen to be considerably larger than the time interval for the asynchronous recognition. The percentage share of the recognized asynchronies which leads to the generation of the alarm is, for example, between 10% and 100%, in some embodiments between 10% and 50%. The alarm can be output, for example, via an interface, for example a display screen or a data connection for remote monitoring.

[0278] Furthermore, the recognition of asynchronies can be used, for example, to identify an unfavorable setting of the artificial respirator 1 and / or an intrinsic PEEP (positive end- exspiratorischer Druck, positive end-expiratory pressure). An unfavorable setting of the artificial respirator 1 can be found, for example, in the pressure setting and / or the flow setting and means a non-optimal or insufficient artificial respiration or support of the biological respiration.

[0279] Figure 6 and Figure 7 The recognition of the premature exhalation trigger 412 by the respiratory effort flow 409 or the determined respiratory flow 403 and the expected respiratory flow 404 is shown exemplarily. In Figure 6In the diagram in Fig. 4, the flow rate 401 of the determined respiratory flow 403 and the expected respiratory flow 404 is plotted against time 402. Two complete breaths 411 are depicted. The flow rate 401 increases strongly at the beginning of the inspiration and then flattens out or decreases again at the end of the inspiration. From the determined flow rate 401, a pressure ramp (start of the pressure ramp 405) is exemplarily started, by which, for example, the pressure preset by the artificial respirator 1 is reduced in order to support, enable and / or induce the expiration of the patient. At the expiration, air escapes from the lungs, i.e. a negative flow rate 401 (expected respiratory flow 404) is expected and also measured (measured respiratory flow 403). After the end of the pressure ramp 406, by means of which the pressure of the respiratory gas is reduced by the artificial respirator 1, a gradual flattening of the flow rate 401 can be observed, which increases again from the negative peak value (or minimum) or approaches a flow rate 401 of 0. From the determined flow rate 401, a pressure ramp is again started, for example, by the artificial respirator 1, by means of which a switch to the inspiration pressure support is made.

[0280] In the case of an early expiration trigger 412, the pressure ramp towards the expiration pressure is started too early. The patient / user has not yet finished the inspiration at this point in time, i.e. still needs air. Therefore, after the end of the pressure ramp 406, a strong increase in the flow rate 401 of the determined respiratory flow 403 can also be identified again up to a local maximum 407. Subsequently, the patient adapts to the expiration, i.e. exhales. Even in the case of no early expiration trigger 412, the flow rate 401 also experiences a local minimum 408 before the flow rate 401 increases again slowly.

[0281] The recognition unit 14, if necessary in conjunction with the calculation unit 13 and / or the preprocessing unit 12 and / or further components of the artificial respirator 1, is exemplarily set up for recognizing an early expiration trigger from the curves of the determined respiratory flow 403 and the expected respiratory flow 404.

[0282] For this purpose, for example, in particular the following four points are checked: the start of the pressure ramp 405 from inspiration to expiration (by the artificial respirator 1), the end of the pressure ramp 406, the position of the local maximum 407 of the respiratory flow, which should not be located further than in a time span of between 0.3 seconds and 0.4 seconds after the end of the pressure ramp 406, and the local minimum 408, which should follow the end of the pressure ramp 406 within a time span of between 0.5 seconds and 0.7 seconds.

[0283] In this exemplary embodiment, an early expiration trigger is detected, for example, when at least one of the following conditions applies:

[0284] 1. The determined respiratory flow 403 is greater than 0 l / min at the beginning of the pressure ramp 405

[0285] 2. The determined respiratory flow 403 is less than 0 l / min at the end of the pressure ramp 405

[0286] 3. e The determined respiratory flow 403 (at the local maximum 407) / the determined respiratory flow 403 (at the end of the pressure ramp 406) < the expected respiratory flow 404 (maximum) / the expected respiratory flow 403 (at the end of the pressure ramp)

[0287] 4. f The determined respiratory flow 403 (at the local maximum 407) > the determined respiratory flow 403 (at the end of the pressure ramp 406)

[0288] 5. g The determined respiratory flow 403 (at the local minimum 408) < the determined respiratory flow 403 (at the end of the pressure ramp 406) + the determined respiratory flow 403 (at the local maximum 407)

[0289] 6. (h < the determined respiratory flow 403 (at the local maximum 407) - the determined respiratory flow 403 (at the end of the pressure ramp 406)) or (h < the expected respiratory flow 403 (local maximum 407) - the determined respiratory flow 403 (at the local minimum 408))

[0290] 7. The determined respiratory flow 403 (at the local minimum 408) < 0

[0291] Here, the coefficient e is in the range of 0.5 to 2.0, preferably between 1 and 1.8; f is in the range of 0.9 to 2.9, preferably in the range of 1.7 to 2.3; g is in the range of 1 to 3, preferably between 1.8 and 2.2; h is in the range of 2 l / min to 10 l / min, preferably between 3 l / min and 7 l / min.

[0292] In some embodiments it is provided that at least 2 or 4 or all of the conditions must apply in order to detect an early exhalation trigger.

[0293] In the curve of the respiratory effort flow 409, an early exhalation trigger 412 can also be identified, as shown in Figure 7 It can be seen that the early exhalation trigger 412 is identified in the curve of the respiratory effort flow 409, as shown in Figure 6The same breath 411, here as a curve of the flow rate 401 over time 402 of the breathing effort flow 409. By the local maximum 407 of the determined breathing flow 403, also a local maximum 410 in the breathing effort flow 409 can be seen. The expected breathing flow 404 does not provide for a direct increase of the flow rate 401 after the end 406 of the pressure ramp, thus here a large difference to the determined breathing flow 403, which is reflected in the very positive local maximum 410 of the breathing effort flow 409. In some embodiments, a statement about the premature exhalation triggering can be made, for example by the height of the local maximum 410 and the position with respect to the end 406 of the pressure ramp. For example, the triggering sensitivity 3 can be controlled in dependence on the height of the local maximum 410. In some embodiments, it can be considered, for example, to adapt the triggering sensitivity 3 in dependence on a saved value for the height of the local maximum 410.

[0294] In some embodiments, the system is designed to adapt the triggering sensitivity 3 in dependence on the premature exhalation triggering 412. Such an adaptation can be performed automatically, for example. If a certain number of premature exhalation triggerings 412 is detected within a (adjustably settable) time period and / or a (adjustably settable) number of breaths 411, the artificial respirator 1 can be set up, for example, so as to recognize that there is a triggering sensitivity 3 that is too sensitive for the switch from inhalation to exhalation. Exemplarily, the triggering sensitivity 3 is then reduced at least for the switch from inhalation to exhalation, i.e. is set to a less sensitive value.

[0295] The (automatic) adjustment of the triggering sensitivity 3 on the basis of the missed breath 218 and / or the short triggering delay 305 and / or the false triggering 307, for example, refers in particular to a (threshold) value that relates to the transition of the inhalation support (for example the switch from exhalation to inhalation). If the premature exhalation triggering 412 is included in the adjustment, this refers in particular to a (threshold) value, according to which the switch from inhalation to exhalation takes place, for example.

[0296] List of reference signs

[0297] 1 artificial respirator

[0298] 2 asynchrony

[0299] 3 triggering sensitivity

[0300] 4 automatic triggering sensitivity

[0301] 11 sensor unit

[0302] 12 preprocessing unit

[0303] 13 computing unit

[0304] 14 recognition unit

[0305] 15 memory unit

[0306] 16 monitoring unit

[0307] 17 control unit

[0308] 18 blower unit / valve unit

[0309] 201 Flow (y-axis)

[0310] 202 Time (x-axis)

[0311] 203 Determined breath flow

[0312] 204 Expected breath flow

[0313] 205 Expected trigger point

[0314] 206 Local maxima

[0315] 207 Expected breath flow

[0316] 208 Breath duration

[0317] 209 Breath effort flow

[0318] 210 Difference (left side)

[0319] 211 Difference (right side)

[0320] 212 Difference (left side)

[0321] 213 Difference (right side)

[0322] 214 Minimum (left side)

[0323] 215 Minimum (right side)

[0324] 216 Breath

[0325] 217 Breath

[0326] 218 Missed breath

[0327] 219 Local maxima

[0328] 301 Flow (y-axis)

[0329] 302 Time (x-axis)

[0330] 303 Determined breath flow

[0331] 304 Expected breath flow

[0332] 305 Trigger delay

[0333] 306 Breathing effort flow

[0334] 307 False triggers

[0335] 308 Short trigger delay

[0336] 309 Breaths

[0337] 401 Flow (y-axis)

[0338] 402 Time (x-axis)

[0339] 403 Determined breathing flow

[0340] 404 Expected breathing flow

[0341] 405 Start point (pressure ramp)

[0342] 406 End point (pressure ramp)

[0343] 407 Local maximum

[0344] 408 Local minimum

[0345] 409 Breathing effort flow

[0346] 410 Local maximum

[0347] 411 Breaths

[0348] 412 Early exhalation trigger

Claims

1. A system for identifying asynchrony between a ventilator (1) and a biological entity, said system comprising at least one ventilator (1), wherein, The artificial ventilator (1) includes at least - Sensor unit (11); - Preprocessing unit (12); - Calculation unit (13); - Identification unit (14), the identification unit is configured to identify the asynchronous (2) relationship between the artificial ventilator (1) and the organism based on the respiratory parameters of the organism. - Memory unit (15); - Monitoring unit (16); - Blower unit and / or valve unit (18); and - Control unit (17), the control unit is configured to automatically control the ventilator (1) at least partially and at least temporarily based on the asynchronous control of the blower unit and / or valve unit (18) identified by the identification unit. The characteristic is that the calculation unit (13) is configured to calculate airway resistance R and lung elasticity E from the measured values ​​measured by the sensor unit (11) and preprocessed by the preprocessing unit (12) using a mathematical lung model; determine the expected respiratory flow (204, 304) and the respiratory effort flow (209, 306) as the deviation between the expected respiratory flow (204, 304) and the determined respiratory flow (203, 303) using the airway resistance R and lung elasticity E, wherein the determined respiratory flow (203, 303) is the patient's respiratory flow calculated from the flow measured by the ventilator (1) after deducting leakage and other effects, wherein the identification unit (14) is further configured to analyze the measured values. The missed breaths (218) are identified and evaluated as asynchronous (2) by the respiratory effort flow (209, 306), the expected respiratory flow (204, 304), and the determined respiratory flow (203, 303), wherein the missed breaths (218) are breaths in which the organism exhibits respiratory effort, but the respiratory effort is not recognized by the ventilator (1), resulting in no inhalation support, wherein the identification unit (14) identifies the missed breaths (218) based on at least two of the following identification features of the respiratory effort flow (209, 306), the expected respiratory flow (204, 304), and the determined respiratory flow (203, 303): - The local maximum value (206) of the determined respiratory flow (203) lies between the two minimum values ​​(214, 215) of the respiratory effort flow (209, 306); - The difference (210) between the time position of the local maximum (219) of the respiratory effort flow (209, 306) and the time position of the corresponding left minimum (214). - The difference (211) between the time position of the local maximum (219) of the respiratory effort flow (209, 306) and the time position of the corresponding right minimum (215). - The difference (212) between the local maximum value (219) of the respiratory effort flow (209, 306) and the corresponding left minimum value (214). - The difference (213) between the local maximum value (219) of the respiratory effort flow (209, 306) and the corresponding right minimum value (215). - The expected respiratory flow (207) at the time point of the local maximum (219) of the respiratory effort flow (209, 306). - The time between the local maximum value (219) of the respiratory effort flow (209, 306) and the expected triggering time (205) of the ventilator (1).

2. The system according to claim 1, wherein, The identification unit (14) identifies the missed breath (218) based on at least four or all of the identification features.

3. The system according to claim 1 or 2, wherein, The identification unit (14) is also configured to identify brief trigger delays (308) and / or erroneous triggers (307) and / or premature expiratory triggers (412) and evaluate them as the asynchronous (2).

4. The system according to claim 3, wherein, The identification unit (14) is also configured to identify the transient trigger delay (308) by analyzing the respiratory effort flow (209, 306), the expected respiratory flow (204, 304), and the determined respiratory flow (203, 303).

5. The system according to claim 3, wherein, The control unit (17) is configured to automatically adjust the trigger sensitivity (3) of the ventilator (1) based on the missed breath (218) and brief trigger delay (308) identified by the identification unit (14).

6. The system according to claim 5, wherein, The control unit (17) is configured to automatically adjust the trigger sensitivity (3) of the ventilator (1) based on the erroneous trigger (307) identified by the identification unit (14).

7. The system according to claim 5 or 6, wherein, The control unit (17) is configured to automatically adapt the trigger sensitivity (3) based on the number of brief trigger delays (308) and missed breaths (218) identified within a time interval between 0.5 minutes and 5 minutes.

8. The system according to claim 5 or 6, wherein, In the case of leakage flow rates greater than the threshold between 15 l / min and 50 l / min, a trigger sensitivity (3) is set in the form of an average trigger sensitivity, which is determined by including trigger sensitivities (3) from previous time periods that have leakage flow rates less than the threshold.

9. The system according to claim 5 or 6, wherein, The trigger sensitivity (3) can be adjusted manually and automatically, wherein the automatic adjustment of the trigger sensitivity (3) can adjust a lower threshold for the parameters used for the trigger compared to the case that can be achieved by manual adjustment.

10. The system according to claim 5 or 6, wherein, The trigger sensitivity (3) includes a value that controls the switching from the inhalation phase to the exhalation phase, wherein the ventilator (1) is configured to adjust the value of the trigger sensitivity (3) based on the identified early exhalation trigger (412), the value of the trigger sensitivity (3) controlling the switching from the inhalation phase to the exhalation phase.

11. The system according to claim 3, wherein, If the trigger delay (305, 308) is less than or equal to a threshold, the trigger delay (305) is identified as a brief trigger delay (308), wherein the threshold is selected in the range of 0 seconds to 0.5 seconds.

12. The system according to claim 11, wherein, The identification unit (14) is configured to identify and determine the trigger delay (305) by means of the misalignment between the biological respiratory effort and the triggering of the artificial ventilator (1).

13. The system according to claim 3, wherein, The ventilator (1) is configured to identify premature expiratory triggers (412) based on the time curves of the determined respiratory flow (403) and / or the expected respiratory flow (404) and / or the respiratory effort flow (409).

14. The system according to claim 3, wherein, The ventilator (1) is configured to identify premature expiratory triggering (412) based on the position and flow rate of the start (405) of the pressure ramp, the position and flow rate of the end (406) of the pressure ramp, the position and flow rate of the determined respiratory flow (403) and / or the position and flow rate of the local maximum (407, 410) and / or the local minimum (408) of the expected respiratory flow (404).

15. The system according to claim 14, wherein, The ventilator (1) is configured to identify an early expiratory trigger (412) when at least one of the following conditions is met: - The determined respiratory flow rate (403) is greater than 0 l / min at the start of the pressure ramp (405); - The determined respiratory flow rate (403) is less than 0 l / min at the end of the pressure ramp (406); - e The local maximum value (407) of the determined respiratory flow (403) / the determined respiratory flow (403) at the end of the pressure ramp (406) < the expected respiratory flow (404) / the expected respiratory flow (404) at the end of the pressure ramp. -f The local maximum value (407) of the determined respiratory flow (403) is greater than the determined respiratory flow (403) at the end of the pressure ramp (406). -g The determined respiratory flow rate (403) at the local minimum (408) is less than the determined respiratory flow rate (403) at the end of the pressure ramp (406) plus the local maximum value (407) of the determined respiratory flow rate (403). - h < the local maximum value (407) of the determined respiratory flow (403) - the determined respiratory flow (403) at the end of the pressure ramp (406) or h < the local maximum value (407) of the determined respiratory flow (403) - the determined respiratory flow (403) at the local minimum value (408). - The determined respiratory flow rate (403) at the local minimum (408) is <0; Wherein, coefficient e is in the range of 0.5 to 2.0; wherein, coefficient f is in the range of 0.9 to 2.9; wherein, coefficient g is in the range of 1 to 3; wherein, coefficient h is in the range of 2 l / min to 10 l / min.

16. The system according to claim 1 or 2, characterized in that, The airway resistance R and the lung elasticity E are determined by the calculation unit (13) through multiple linear regression and a single-chamber lung model.

17. The system according to claim 7, wherein, The time interval is between 1 minute and 3 minutes.

18. The system according to claim 8, wherein, The threshold is 25 l / min.

19. The system according to claim 11, wherein, The threshold is selected in the range of 0 seconds to 0.25 seconds.

20. The system according to claim 11, wherein, The threshold is selected in the range of 0 seconds to 0.15 seconds.

21. The system according to claim 15, wherein, The coefficient e is between 1 and 1.

8.

22. The system according to claim 15, wherein, The coefficient f is between 1.7 and 2.

3.

23. The system according to claim 15, wherein, The coefficient g is between 1.8 and 2.

2.

24. The system according to claim 15, wherein, The coefficient h is between 3 l / min and 7 l / min.

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