Ventilation device and operating procedure for a ventilation device with a determination of cough attacks

Abstract

Method for operating a ventilator (1) with a determination of cough attacks, wherein the ventilator (1) is configured to process sensor signals (97, 99) provided by sensors (11, 13, 15, 17, 19, 21) of the ventilator (1), wherein the sensor signals (97, 99) indicate pneumatic and fluidic physical states of a respiratory gas in a gas-carrying connection system (5, 7, 9) connected and coupled to the ventilator (1) and to a patient (3) and configured for the transport of gases to and from the patient (3), from which values ​​of an airway pressure P present in the gas-carrying connection system (5, 7, 9) can be derived. AW (99) and a flow rate V̇ Pat (97) as well as flow directions associated with the flow rate (97) in the gas-carrying connection system (5, 7, 9) can be determined, where, after initializing an analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and a data set, the following sequence of steps is repeatedly executed: - Recording of pneumatic and fluidic physical states with determination of values ​​of pressure (99), flow rates (97) and flow directions as a data set, - Determining whether a situation of interaction between ventilator (1) and patient (3) with an increased airway pressure P exists AW is given, based on a comparison, whether an exceedance of a comparison criterion indicating an increased airway pressure by the determined value (99) of the airway pressure P AW is given - Determining whether a situation of interaction between ventilator (1) and patient (3) exists in which a smaller quantity of respiratory gas is delivered from the ventilator (1) to the patient (3) than flows out of the patient (3), based on a comparison of whether an exceedance of a comparison criterion indicating a flow rate and a flow direction by the determined value (97) of the flow rate V̇ Pat and is determined by the specific direction of flow, - Determination based on at least one evaluation criterion which pneumatically / fluidically indicates physical states of pressure, flow rate and / or volume of an interaction between ventilation device (1) and patient (3), whether in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') a condition exists which indicates at least one coughing attack, - Provision of a control signal (131) which indicates the condition that indicates a coughing attack, - Update of the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and the amount of data.

Description

[0001] The present invention relates to a ventilator device with a determination of conditions with coughing attacks, as well as an operating method for a ventilator device with a determination of coughing attacks.

[0002] The ventilator can be designed as a ventilator for adult patients or children, as an emergency ventilator for use in rescue or recovery operations on land, at sea, or in the air, or as a special, so-called neonatal ventilator for ventilating newborns. Devices for ventilating patients are known from the state of the art. The aforementioned ventilators, emergency ventilators, and neonatal ventilators enable patients to be mechanically ventilated—mandatory or assisted. Ventilators are primarily used in intensive care units for the treatment of patients whose own capacity to supply breathable air and oxygen, as well as to remove carbon dioxide, is reduced or limited by the patient's own respiratory activity.

[0003] State-of-the-art ventilators for performing mechanical ventilation are described in US 2,904,035, US 5,400,777, US 5,937,853, WO 2007 / 085110 A1.

[0004] For the operation of ventilators, it is necessary that inadmissible operating conditions are avoided and that operating situations that could lead to inadmissible operating conditions are detected as early and as timely as possible in order to avoid the possible occurrence of inadmissible operating conditions.

[0005] The scientific article “Fuzzy Logic Cough Detection: A First Step Towards Clinical Application” published in “Fuzzy Systems, 1994. IEEE World Congress on Computational Intelligence, Proceedings of the Third IEEE Conference, IEEE 1994, pages 1000 - 1005” describes how cough can be detected by interpreting pressure signals using fuzzy logic and a lung model.

[0006] DE 101 64 313 A1 discloses a ventilator with a control unit and sensors. The sensors transmit physical data to the control unit, indicating the volume of respiratory gas delivered to and from the patient. Changes or differences can provide information about possible volume differences or leaks.

[0007] DE 10 2016 007 336 A1 discloses a method for alarm management in a ventilator, for example, an anesthesia or ventilator, as well as a medical device with alarm management during patient ventilation. DE 10 2016 007 336 A1 describes how, when a single cough event is detected, the ventilator triggers an alarm indicating increased airway pressure in a different manner than in a different state of the ventilator – in accordance with the ISO 80601-2-12 standard.

[0008] This patent application DE 10 2016 007 336 A1 shall be deemed to be incorporated into this description by means of this reference with regard to the sensor technology described therein for pneumatic / fluidic physical conditions such as pressure and flow rates and the measuring locations suitable for the sensor technology, with its disclosure content.

[0009] At this point, the fundamental relationships and situations and causes in which increases in airway pressure may occur, which are necessary for understanding, will therefore only be listed in brief.

[0010] For further details, please refer to application DE 10 2016 007 336 A1 filed by the applicant on 16 June 2016. • Disturbances in the dosage of breathing gas: Disturbances in flow / volume / or pressure control are possible causes of increased airway pressure. Such disturbances can be caused, for example, by mechanical or pneumatic components, such as valves or dosing units, that are malfunctioning. • Blockages in the gas supply: Another cause of increased airway pressure can be a compromise in the gas-carrying elements. Blockages in the gas-carrying elements, such as ventilation tubes, can impede the supply and / or removal of breathing air to or from the patient. For example, a narrowing or a kink in the continuation of the tube from the patient can lead to increased ventilation pressure building up ahead of the kink. • Accumulation of condensate and secretion: In a similar way to how kinks in the tube affect the pressure conditions within the tube or on the patient, accumulations of water, which can occur due to condensation of the humidified inhaled air and the humid exhaled air in the tube, also have an effect that can increase airway pressure. Another possible cause of increased airway pressure is the accumulation of secretions in an endotracheal tube used for ventilation, which is inserted through the oral cavity into the patient's trachea. Such accumulations increase the flow resistance in the endotracheal tube and thus lead to excessive pressure. • Counterbreathing: Another possibility for increases in airway pressure arises in situations involving what is known as counterbreathing by the patient. Counterbreathing refers to the condition in which the ventilator, in order to perform mechanical ventilation, is pushing air to or into the patient, while the patient simultaneously attempts to exhale, i.e., counterbreathe. In this case, the patient and ventilator are not synchronized during the inspiration / expiration phases. This condition is quite stressful for the patient and should therefore be avoided if possible. • User interactions: Other causes of increases in airway pressure include user adjustments, such as changes to limit values ​​or changes in pressure and volume values. Such user interactions can cause pressure changes and thus increases in airway pressure. • Coughing events:For example, in certain situations, such as those caused by secretions in the upper airways or the endotracheal tube, or blockages in the endotracheal tube, a cough reflex can occur in the patient. Regardless of whether the current ventilation phase of the ventilator is an inspiration phase or an expiration phase, such a cough reflex is usually an event in which, suddenly, almost like a pulse, an additional amount of exhaled respiratory gas enters the tube system with the cough, thus causing an increased flow rate to flow away from the patient. This pulse-like increase in flow rate subsequently causes a brief, massive pressure increase or transient pressure event.A cough or coughing fit is often observed when, during the waking phase—for example, after a surgical procedure—accumulated secretions in the bronchi or the lower and upper respiratory tract trigger a cough reflex. The cough reflex typically persists as long as the situation persists, such as blockages in the endotracheal tube, accumulation of secretions in the endotracheal tube or in the upper respiratory tract, or uncomfortable or even irritating or painful positioning of the endotracheal tube in the trachea. In such cases, the coughing impulse or cough reflex can develop from individual coughing episodes into a cough sequence or a so-called coughing attack.

[0011] In unfavorable circumstances, depending on the patient's constitution and clinical picture, coughing attacks can not only be uncomfortable for the patient, but also have a detrimental impact on the recovery process. In individual cases, they can even pose life-threatening consequences for the patient if such a coughing attack lasts for a longer period of time. Potential life-threatening consequences include strenuous physical exertion and psychological stress, which are generally detrimental to the recovery process.

[0012] Possible physical exertion includes, for example, strain on the cardiovascular system with an increase in heart rate (pulse) and blood pressure.

[0013] Possible threatening consequences include, for example, the patient being undersupplied with oxygen, as the coughing attacks make it difficult and hinder the supply of the necessary amounts of fresh, oxygen-rich respiratory gas.

[0014] Possible physical exertion may arise partly from the coughing attacks directly, as the patient experiences shortness of breath with accompanying fear of suffocation, and partly from the combination of the stress on the cardiovascular system, as anxiety situations of various kinds, for example, situations of helplessness felt by the patient. Coughing attacks usually only end when the situation causing them no longer exists—for example, when the patient has managed to expel the secretion causing the blockage by coughing, or when the medical staff's actions result in a change in the patient's situation.

[0015] In order for medical personnel to take appropriate measures to change the situation, it is advantageous that situations involving coughing attacks are detected when a patient is being ventilated and that an appropriate alarm is issued.

[0016] There is therefore a need to identify situations involving coughing attacks as disruptive factors in ventilation in order to make ventilation as comfortable and low-risk as possible for the patient. OBJECT OF THE INVENTION

[0017] It is therefore an object of the present invention to provide a ventilator with a determination of conditions with coughing attacks during operation of the ventilator.

[0018] Furthermore, it is an object of the present invention to provide a method for operating a ventilator with a determination of coughing attacks. SOLUTION TO THE TASK

[0019] This object is achieved by the enclosed, independent patent claims, in particular by a method for operating a ventilator with a determination of coughing attacks with the features of patent claim 1 and by a ventilator with the features of patent claim 13.

[0020] Advantageous embodiments of the invention emerge from the subclaims and are explained in more detail in the following description with partial reference to the figures.

[0021] According to the invention, it is provided that in a ventilation device which is suitable and designed for ventilating a patient or living being, existing measured values, signals from sensors, also referred to as sensor signals, are used to detect whether conditions which indicate coughing attacks are present.

[0022] The ventilator on which the method for operating a ventilator with a determination of coughing attacks is carried out is preferably designed as a ventilator suitable for long-term ventilation for use in an intensive care unit of a hospital.

[0023] Disturbances in the supply and removal of respiratory gases from a patient's airways occur at the pneumatic / fluidic access, e.g. in the endotracheal tube or at the transition of the endotracheal tube due to blockages or accumulations of viscous fluids, such as secretions or blood.

[0024] Such blockages or accumulations of viscous fluids increase the flow resistance in the endotracheal tube and can thus lead to an increase in the airway pressure P AWThis results in the triggering of a cough reflex or a coughing reflex, resulting in a cough event that occurs, which corresponds to the normal rhythm of inspiration and expiration as a transient increase in the airway pressure P AW in combination with a short-term increase in the patient’s exhaled flow rate V̇ Pat is superimposed. An uncomfortable positioning of the endotracheal tube in the throat can also cause irritation in the trachea, which can trigger coughing reflexes.

[0025] A cluster of multiple coughing episodes in quick succession, for example, within a time interval of less than one second to a few seconds, indicates a coughing attack. Conditions that indicate coughing attacks include situations in which a patient is triggered by external factors, such as irritation, particularly skin irritation in the trachea or pharynx, which may be caused by an uncomfortable position of an endotracheal tube in the upper respiratory tract (bronchi, trachea).

[0026] Such coughing attacks with multiple increases in the patient’s exhaled flow rates V̇ Pat result, considered over a time interval, in a volume V̇ that can be balanced in the time interval Pat above the patient's typical tidal volume VT .

[0027] To evaluate the situation and to distinguish whether a coughing attack of the patient is due to an increase in airway pressure P AW or for a short-term increase in the flow rate V̇ exhaled by the patient Pat Sensor signals are available for evaluation to determine the cause. These sensors include pressure sensors and flow sensors located in or on the ventilator or arranged in or on gas-carrying elements or connecting systems, such as hose systems.

[0028] Measuring locations in or on the ventilator at which pressure measurements and flow measurements can be carried out and from which both determinations of the airway pressure and determinations of the patient flow rate are possible are an inspiratory measuring location and an expiratory measuring location within or on the ventilator for mechanical ventilation of a patient, as well as a patient-near measuring location (Y-piece), outside and proximal to the ventilator, for example in or on the gas-carrying elements or connection systems.

[0029] Table 1 below lists three fundamentally different suitable measurement locations for pressure and flow measurement: an inspiratory measurement location and an expiratory measurement location within the ventilator for ventilating a patient, as well as a patient-near measurement location (Y-piece), outside and proximal to the ventilator for ventilating a patient. The measured values ​​recorded at these measurement locations are shown, as are the measured variables that can be derived, calculated, or determined from these measured variables. Table 1 Measuring location Recorded pressure measurement value Determinable pressure measurement Recorded flow measurement value Determinable flow measurement Inspiratory (inhalation) Inspiratory pressure P insp P AW = P insp -P hose_insp Inspiratory flow rate V̇ insp V̇ Pat = V̇ exsp -V̇ insp Expiratory (exhalation) Expiratory pressure P exsp P AW = P exsp + P hose_exsp Expiratory flow rate V̇ exsp near the patient (proximal) PatientenDruck P Pat P AW = P Pat Patient flow rate V̇ Pat V Pat Quantity & Direction

[0030] In Table 1 above, the following means: P aw = airway pressure, P Pat = estimated pressure in the patient's lungs based on the pressure measured near the patient, P insp = Inspiratory pressure at the inspiratory outlet of the ventilator, P exsp= Expiratory pressure at the expiratory inlet of the ventilator, P hose_insp = Pressure gradient on the inspiratory ventilation tube, P hose_exsp = Pressure gradient on the expiratory ventilation tube, V̇ pat = patient flow rate, V̇ exsp = expiratory flow rate into the expiratory inlet of the ventilator, V̇ insp = inspiratory flow rate from the inspiratory outlet of the ventilator.

[0031] According to a first aspect of the invention, the object is achieved by a method according to the invention for determining conditions which indicate coughing attacks in a patient.

[0032] The method according to the invention is designed to detect conditions which indicate coughing attacks of a patient during interaction between patient and ventilator and, based on these detected conditions with coughing attacks, to provide an output of a control signal indicating a condition of a coughing attack for an alarm.

[0033] The ventilation device is designed to process sensor signals provided by sensors arranged in or on the ventilation device or connected to the ventilation device. The sensor signals pneumatically / fluidically indicate physical states of a respiratory gas in a gas-conducting connection system that is connected and coupled to the ventilation device and a patient and designed to transport gases to and from the patient. The connection system is preferably designed as a ventilation tube, more preferably as a combination of an inspiratory ventilation tube and an expiratory ventilation tube. Alternatively, a coaxial ventilation tube system, such as a so-called "single-tube system," can be used.

[0034] From the sensor signals, values ​​of a current airway pressure P in the gas-carrying connection system can be determined. Awand a flow rate flowing in the gas-carrying connection system, as well as flow directions associated with the flow rate in the gas-carrying connection system.

[0035] The method according to the invention for determining conditions that indicate coughing attacks uses these sensor signals to determine the airway pressure P AW , as well as for the determination, evaluation, and classification of conditions and situations, as well as operating states in the gas-carrying connection system and / or ventilation device. In the method according to the invention, temporary elevations in the airway pressure P are detected by evaluating signals from the pressure sensors and flow sensors. AW as well as increases in the patient’s exhaled flow rates V̇ Patidentified as coughing events. Multiple coughing events in quick succession are assessed in the method according to the invention as a condition indicating a coughing attack.

[0036] Based on this, the method according to the invention provides a control signal indicating this condition. This control signal is provided or output to alert the condition indicating a coughing attack.

[0037] In the method according to the invention for determining conditions with coughing attacks in a ventilator, after initializing an analysis time interval and a data set, the following steps are carried out in a repeating sequence of steps: - Recording of pneumatic and fluidic physical conditions with determination of pressure and flow rates as data set, - Determination of whether a situation of interaction between the ventilator and the patient with an increased airway pressure exists, based on a comparison of whether an exceedance of a comparison criterion indicating an increased airway pressure is given by the determined value of the airway pressure, - Determining whether a situation of interaction between the ventilator and the patient exists in which a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, based on a comparison of whether an exceedance of a comparison criterion indicating a flow rate and a flow direction is given by the determined value of the flow rate and by the determined flow direction, - Determination on the basis of at least one evaluation criterion which pneumatically / fluidically indicates physical conditions of pressure, flow rate and / or volume of an interaction between the ventilator and the patient, whether a condition exists in the analysis time interval which indicates at least one coughing attack, - Providing a control signal indicating the condition that indicates a coughing attack, - Updating the analysis time interval and data volume.

[0038] The data volume is selected to correspond to the analysis time interval. When initializing the analysis time interval and the data volume, a sufficient amount for the analysis and the duration of the analysis time interval is stored in a data store, and the starting point of the analysis time interval is set before the start of the continuous execution of the procedure for determining states with coughing attacks.

[0039] The analysis time interval is updated over the course of the recording with the temporal progress of the recording, resulting in a sliding time interval, which is characterized in that the most recent values ​​of pressure and flow rate are included in the data set to determine the condition that indicates at least one coughing attack, and the oldest values ​​of pressure and flow rate in the data set are no longer included in the determination of the condition that indicates at least one coughing attack. When updating the analysis time interval and the data set, the analysis time interval and the corresponding data set are updated by a predetermined time interval or a predetermined number of values ​​of pressure and flow rate over the course of the recording.This is done, for example, by shifting the data set by one or more samples of the pressure and flow rate values ​​over time.

[0040] The situation in which a larger amount of breathing gas is delivered or flows from the ventilator to the patient via an inspiratory connection system (inspiratory ventilation tube) than flows away from the patient corresponds to the inspiration phase (inhalation).

[0041] The situation in which a smaller amount of respiratory gas is delivered or flows from the ventilator to the patient via the inspiratory connection system than flows away from the patient and flows back into the ventilator, for example via an expiratory connection system, corresponds to the expiratory phase (exhalation).

[0042] The situation of the interaction between the ventilator and the patient, in which a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, usually corresponds to an expiratory phase (exhalation), or a period of at least short-term exhalation and in connection with the increase in the airway pressure in cases where the increase in the airway pressure P AW not directly attributable to dosage disturbances or user interactions, a cough event.

[0043] In inspiration phases, as well as in expiration phases, situations arise in which, due to one or more coughing events or cough sequences, additional amounts of exhaled respiratory gas are given as, at least temporarily, increases in the flow rate in the gas-carrying connection system (ventilation tube) and lead to increases in the airway pressure P AWlead.

[0044] These at least temporary increases in airway pressure P Aw with a simultaneity of the interaction of the ventilator and the patient, in which a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, as an indication of conditions with coughing attacks are determined on the basis of the sensor signals of the sensors arranged at the measuring points of the ventilator or on the gas-carrying connection system.

[0045] In situations of interaction between ventilator and patient in which a condition exists which indicates a coughing attack, the ventilator provides and / or issues a control signal or output which indicates this condition.

[0046] This could, for example, be a signal that enables the output of a warning, message, audible alarm, or visual alarm to medical personnel directly at the ventilator. Such a control signal can also be forwarded to a remote unit for issuing alarms and messages, for example, in the nurses' station, or to a mobile data output system (pager, mobile phone) using suitable and common data transmission channels (telephone, SMS, LAN, WLAN, network, Bluetooth).

[0047] Preferably, in the method for determining conditions with coughing attacks during operation of the ventilator, signals from at least one pressure sensor are used, the signals of which indicate the at least temporary increases in the airway pressure P AW indicate, as a basis for the values ​​for determining the airway pressure P AW used.

[0048] Preferably, this at least one pressure sensor is arranged on the connection system, close to the mouth / nose area of ​​the patient on the patient connection path or on the connection element (Y-piece).

[0049] Further preferably, the at least one pressure sensor or a further pressure sensor is arranged on the inspiratory connection system. Further preferably, the at least one pressure sensor or a further pressure sensor is arranged on the expiratory connection system.

[0050] In a further embodiment, a possible comparison criterion which indicates an increased airway pressure P AWindicated, a predetermined pressure threshold is selected. For example, a pressure value above a pressure threshold, such as 30 hPa ± 3 hPa, characterizes elevated airway pressure for an adult patient, as well as, in a comparable manner, for an adolescent or child patient. A pressure value above a pressure threshold of 20 hPa ± 1 hPa characterizes elevated airway pressure for an infant patient.

[0051] In a further preferred embodiment of the method, in order to determine whether, due to the interaction of the ventilator and the patient, a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, it is determined on the basis of a comparison whether an exceedance of a comparison criterion indicating a flow rate and a flow direction is given by the determined value of the flow rate and by the determined flow direction.

[0052] One possible comparison criterion that indicates the flow rate and flow direction is a predetermined flow rate threshold associated with a flow direction. For example, a flow rate above a flow threshold, for example, approximately 2.5 liters per minute ± 0.2 liters per minute, with a corresponding flow direction away from the patient, characterizes exhalation (expiration). For example, a flow rate above a flow threshold, for example, 1.5 liters per minute ± 0.2 liters per minute, with a corresponding flow direction toward the patient, characterizes inspiration (inspiration).

[0053] For example, a flow rate below a flow threshold, such as 2.5 liters per minute ± 0.2 liters per minute, with a corresponding flow direction away from the patient, characterizes the end of expiration or an expiratory pause. For example, a flow rate below a flow threshold, such as 1 liter per minute ± 0.2 liters per minute, with a corresponding flow direction toward the patient, characterizes the beginning or end of inspiration or an inspiratory pause.

[0054] These flow rates are determined based on the sensor signals from the sensors located at the measuring points of the ventilator or on the gas-carrying connection system.

[0055] Preferably, signals from at least one flow sensor, whose signals indicate the flow rates and flow directions in the connection system, are used in the method for determining conditions with coughing attacks during operation of the ventilator.

[0056] Preferably, this at least one flow sensor is arranged on the connection system, close to the mouth / nose area of ​​the patient on the patient connection path or on the connection element (Y-piece).

[0057] Further preferably, the at least one flow sensor or a further flow sensor is arranged on the inspiratory connection system.

[0058] Further preferably, the at least one flow sensor or a further flow sensor is arranged on the expiratory connection system.

[0059] In a further preferred embodiment of the method, in order to determine whether, due to the interaction of the ventilator and the patient, a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, and thus an indication of conditions with coughing attacks is given, at least one piece of information from a sequence of the control of the ventilator with regard to the current breathing phase or information with regard to a state of an expiratory valve or a control signal for such an expiratory valve is taken into account.

[0060] By controlling the expiratory valve during mechanical ventilation, such as mandatory or assisted ventilation, the ventilator ensures the continuous progression of expiratory phases (exhalation) and inspiration phases (inhalation) based on the respiratory rate (RR) and the inspiration / expiration ratio (I:E). Thus, in many situations, at least some information about the current breathing phase can be derived from the status and control of the expiratory valve.With such information about the valve status (closed, open, output level), it is possible, particularly in the case of ventilation with mandatory ventilation modes, to verify from the control sequence whether a smaller amount of respiratory gas is being delivered from the medical device to the patient than is flowing away from the patient, i.e. whether there is an expiratory phase on the part of the medical device - which is then usually mandatory and specified by the medical device.

[0061] In a preferred embodiment of the method, the analysis time interval is preferably selected within a range of 20 seconds to 60 seconds or within a range of one or two to six consecutive respiratory cycles. Such an analysis time interval of 20 seconds to 60 seconds typically comprises a number of approximately three, four, to six coughing events, which together constitute a coughing attack. Depending on the patient's coughing behavior, limiting the analysis time interval to a preferred range of 20 seconds to 40 seconds or to a maximum of four consecutive respiratory cycles can be helpful in detecting conditions involving coughing attacks with a short time delay.

[0062] An analysis of cough events to identify cough attacks can be carried out in various ways, each of which, individually or in combination, allows the determination of the condition that indicates a cough attack.

[0063] For the analysis, at least one evaluation criterion from the following list of evaluation criteria, which indicate pneumatic / fluidic physical states of an interaction between the ventilator and the patient, is used. a. Evaluation criterion: Number of cough events, pressure-based If in an analysis time interval with a given time duration T a , a predetermined minimum number of cough events by increasing the airway pressure P AW above a predetermined pressure threshold value chosen as a comparison criterion, this is evaluated in such a way that a condition exists which indicates a coughing attack.

[0064] Counting the number of individual pressure elevations based on cough events in the analysis time interval provides a measure of the frequency of cough events in the analysis time interval as a basis for assessing that a condition exists that indicates a cough attack. b. Evaluation criterion: Number of cough events, flow-based If in an analysis time interval with a given time duration T b , a predetermined minimum number of cough events by increasing the flow rates V̇ exhaled by the patient Pat above a predetermined flow threshold value selected as a comparison criterion, this is evaluated in such a way that a condition exists which indicates a coughing attack.

[0065] Counting the number of individual flow rate excesses based on cough events in the analysis time interval provides a measure of the frequency of cough events in the analysis time interval as a basis for assessing that a condition exists that indicates a cough attack. c. Evaluation criterion: Weighting of cough events If in an analysis time interval with a given time duration T c an integral over time from determined pressure values, which increases in airway pressure P AW indicate, for example, a time integral of all pressure values ​​above a predetermined pressure threshold value, exceeds a predetermined pressure integral threshold value in the analysis time interval, this is evaluated in such a way that a condition exists which indicates a coughing attack.

[0066] The formation of the time integral over the pressure values ​​of the airway pressure P AWThis results in a pressure integral that can be described as a "pressure-specific cough effect," since it is not the exact number of coughing events themselves that is summed up, but rather the effect of a multitude of individual, varyingly long-lasting pressure increases with different pressure levels or pressure peaks during the course of ventilation. The pressure integral can be viewed as a kind of summary effect of increases in airway pressure P AW be viewed. d. Evaluation criterion: Weighting of cough events, volume-based If in an analysis time interval with a given time duration T dIf an integral over time from determined flow rate values ​​that indicate increases in flow rates, for example, a time integral of all flow rates above a predefined flow rate threshold exceeds a predefined flow integral threshold in the analysis time interval, this is evaluated in such a way that a condition exists that indicates a coughing attack. This results in an evaluation based on "cough volumes" on the basis of cough events, which are determined by means of excesses in the flow rates V̇ exhaled by the patient. Pat were determined.

[0067] The formation of the time integral over the flow rate values ​​results in a volume that can be described as a “flow-specific cough volume”, since only volume portions are summed during the course of ventilation whose flow rates cause increases in the airway pressure P AW are given. e. Evaluation criterion: Weighting of cough events, pressure-based If in an analysis time interval with a given time duration T e If an integral over time from determined flow rate values ​​which correspond in time to determined pressure values ​​which indicate increases in airway pressure, for example a time integral of all flow rates above a predetermined flow rate threshold value exceeds a predetermined flow integral threshold value in the analysis time interval, this is evaluated in such a way that a condition exists which indicates a coughing attack.

[0068] One or more cough events, which are based on the airway pressure P AW were determined, with regard to whether these identified cough events together result in a cough attack, in relation to the volumes V̇ exhaled by the patient resulting from the cough eventsPat rated.

[0069] This results in an assessment based on “cough volumes” on the basis of cough events, which are determined by means of increases in airway pressure P AW The formation of the time integral over the flow rate values ​​results in a volume that can be described as a “pressure-specific cough volume”, since only those “volume portions” during the ventilation are summed up by means of the integral, at which simultaneous increases in the airway pressure P AW are given.

[0070] The following preferred embodiments describe embodiments applying the evaluation criteria according to the list (a. - e.) of evaluation criteria.

[0071] In a preferred embodiment of the method, a comparison with a predetermined minimum number of coughing events in the analysis time interval, for example a number of 4 to 6 coughing events, is used as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack.

[0072] In a further preferred embodiment of the method, as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a comparison with a predetermined minimum number of coughing events, for example a number of four or more coughing events, on the basis of increases in the airway pressure P AW above the predetermined pressure threshold.

[0073] The predetermined pressure threshold value for determining cough events is preferably selected in a range of 30 hPa ± 3 hPa for adults, adolescents or children, or in a range of 20 hPa ± 1 hPa for infants and / or toddlers.

[0074] In a further preferred embodiment of the method, as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a comparison with a predetermined minimum number of coughing events, for example an exceedance of a number of at least 4 to 6 coughing events, on the basis of increases in the flow rates V̇ exhaled by the patient is carried out in the analysis time interval. Patabove the predetermined flow rate threshold. The predetermined flow rate threshold for determining cough events can be selected as a threshold in a range from 90 l / min to 180 l / min, for example, a flow rate above 120 l / min. The analysis time interval is preferably selected in a range from 20 seconds to 60 seconds or in a range from 2 to 6 consecutive respiratory cycles.

[0075] In a preferred embodiment of the method, at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack is a summary effect of individual coughing events, i.e. events with respective increases in the airway pressure P AW above the predetermined pressure threshold, by forming a time integral of the increases in airway pressure P AW applied in the analysis time interval.

[0076] In this case, exceeding a predetermined threshold value by the coughing events is considered an indication of a coughing attack. This predetermined threshold value can be applied, for example, in units of pressure (hPa, mbar) or as a dimensionless numerical value.

[0077] Preferably, a multiple of the pressure threshold is selected, e.g., 3 to 5 times. The analysis time interval is preferably selected in a range of 20 seconds to 60 seconds or in a range of 2 to 6 consecutive breathing cycles.

[0078] In a preferred embodiment of the method, a minimum amount of a flow rate in the analysis time interval, corresponding to a minimum volume that has flowed away from the patient due to coughing events in the analysis time interval, is used as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack.

[0079] In a further preferred embodiment of the method, at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack is a summary effect of individual coughing events, i.e. events with respective increases in the flow rates V̇ exhaled by the patient. Pat above the predetermined flow rate threshold, by forming a time integral of the increases in the flow rates exhaled by the patient V̇ Patapplied in the analysis time interval. The predetermined flow rate threshold for determining cough events is preferably selected in a range of 90 l / min to 180 l / min. Exceeding a predetermined minimum volume or a predetermined volume threshold by the cough events is considered an indication of a coughing attack.

[0080] The predetermined minimum volume can be related to the tidal volume V T or to the patient's minute volume MV, for example, an integral volume of 10% - 20% above the tidal volume V Tor a sudden exceedance of the previously calculated minute volume by 5% to 10%. Exceeding the predetermined minimum volume can also be determined by exceeding a predetermined volume threshold, which, for example, corresponds to at least 3 to 5 times a typical tidal volume.

[0081] With a typical tidal volume of 0.5 liters ± 0.2 liters, possible values ​​for both the minimum volume and the volume threshold range from approximately 1 liter to 3 liters. The analysis time interval is preferably selected within a range of 20 seconds to 60 seconds or within a range of 2 to 6 consecutive breathing cycles.

[0082] In a preferred embodiment of the method, at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack is a summary effect of individual coughing events, i.e. events with respective increases in the airway pressure P AW above a predetermined pressure threshold, by forming a time integral of the increases in flow rates corresponding to the cough events in the analysis time interval.

[0083] The predetermined pressure threshold for determining cough events is preferably selected within a range of 30 hPa ± 3 hPa for adults, adolescents, or children, or within a range of 20 hPa ± 1 hPa for infants and / or toddlers. The predetermined volume threshold can also be set in relation to the tidal volume V Tor the patient's minute volume MV. For example, an integral volume of 10% - 20% above the tidal volume or a sudden exceedance of the previously calculated minute volume by 5% to 10% can be selected as the volume threshold. The predetermined volume threshold can also be selected as a volume value that corresponds, for example, to at least three times a typical tidal volume. With a typical tidal volume of 0.5 liters ± 0.2 liters, possible values ​​of approximately 1 liter to 3 liters result for the volume threshold. The analysis time interval is preferably selected in a range of 20 seconds to 60 seconds or in a range of 2 to 6 consecutive respiratory cycles.

[0084] The described embodiments represent, individually as well as in combination or combinations with one another, particular embodiments of the method according to the invention for determining conditions with coughing attacks during operation of the ventilator in a ventilator. All possible further embodiments and their advantages resulting from combination or combinations of several embodiments are nevertheless also encompassed by the inventive concept, even if not all possible combinations of embodiments are explained in detail.

[0085] The above-described embodiments of the method according to the invention can also be designed in the form of a computer-implemented method as a computer program product with a computer, wherein the computer is caused to carry out the above-described method according to the invention when the computer program is executed on the computer or on a processor of the computer or a so-called "embedded system" as part of a medical device.

[0086] The computer program can also be stored on a machine-readable storage medium.

[0087] In an alternative embodiment, a storage medium can be provided which is intended for storing the above-described, computer-implemented method and is readable by a computer. It is within the scope of the present invention that not all steps of the method necessarily have to be executed on one and the same computer instance; rather, they can also be executed on different computer instances. The sequence of the method steps can also be varied if necessary. Furthermore, it is possible for individual sections of the above-described method to be executed in a separate unit, for example, a unit that can be sold separately.

[0088] The solution to the problem has been described above with reference to the method claimed as the first aspect of the invention. In addition, a further aspect results in a ventilation device designed to carry out the method according to the invention in accordance with at least one of the described embodiments.

[0089] Features mentioned for the method, described advantages, or alternative embodiments are also applicable to the other claimed subject matter, and vice versa. The corresponding functional features of the method are implemented by corresponding physical modules of the ventilation device, in particular by hardware components (μC, μP, DSP, FPGA, ASIC, GAL, logic components), which can be implemented, for example, in the form of a processor (μP), multiple processors, or in the form of instructions in an internal or external memory or memory area that are processed by the processor.

[0090] The advantages described for the method according to the invention can be achieved in the same or similar manner with the ventilation device according to the invention. Furthermore, the described embodiments and their features and advantages of the method can be transferred to the ventilation device, just as the described embodiments of the ventilation device can be transferred to the method.

[0091] According to the invention, the task of determining conditions which indicate coughing attacks in a patient is also achieved by a ventilation device according to the further aspect of the invention.

[0092] This ventilation device is designed for mechanical, mandatory, or assisted ventilation of a patient and, according to the invention, comprises a connection system designed for transporting respiratory gases, a pressure measuring unit, a flow measuring unit, a control unit, a dosing unit, and an alarm unit. The control unit is preferably designed as a microprocessor module (µC) with associated internal and / or external data memory (RAM). The flow measuring unit, as well as the pressure measuring unit, are designed to convert electrical signals indicating physical measured variables, which are provided by the flow rate and pressure sensors, into data signals suitable for data processing. In typical configurations of anesthesia and ventilation devices, the flow measuring unit, the pressure measuring unit, and the alarm unit are designed as elements or modules of the control unit.

[0093] The connection system has an expiratory path which is designed and provided for carrying an expiratory amount of respiratory gas from the patient. The connection system has an inspiratory path which is designed and provided for supplying an inspiratory amount of respiratory gas to the ventilator to the patient. The connection system has a patient connection path which is designed and provided for supplying the inspiratory amount of respiratory gas from the ventilator to the patient and for carrying the expiratory amount of respiratory gas from the patient. The expiratory path and the inspiratory path are connected to one another and to the patient connection path by means of a connecting element. The connecting element can be, and in practice is often, designed as a so-called Y-piece.

[0094] The flow measurement unit comprises at least one flow sensor, which is arranged in or on the connection system or in or on the ventilation device and is intended to detect at least one flow rate of a quantity of respiratory gas flowing away from the patient in the connection system or flowing from the ventilation device to the patient. The flow measurement unit is designed to provide this at least one flow rate measurement value to the control unit.

[0095] The pressure measuring unit has at least one pressure sensor which is arranged in or on the ventilation device or the connection system and is intended to detect a pressure measurement value of a pressure which is present in the connection system and the pressure measuring unit is designed to provide this at least one pressure measurement value to the control unit.

[0096] The control unit is designed, preferably by means of an interface, to receive pressure measurement values ​​and flow measurement values, preferably from the pressure measuring unit and from the flow measuring unit, or to read them in via a data connection.

[0097] The control unit is designed to compare the recorded pressure measurement value with a predetermined pressure threshold value.

[0098] The control unit, in conjunction with the dosing unit, is designed to suitably control or regulate an arrangement of valves in order to enable a ventilation process with pressure control or volume control, limit value monitoring for pressures and volumes with the design of a ventilation frequency and durations (I:E) of inspiration phase and expiration phases to take effect on the patient by means of the ventilation device.

[0099] The control unit is further configured to compare the at least one detected flow rate measurement value with a predetermined flow rate threshold value and to determine, on the basis of the comparison, whether the at least one flow rate measurement value exceeds a predetermined flow rate threshold value.

[0100] The control unit is further configured to determine whether the at least one flow rate measurement and the associated flow direction indicate a situation during an exhalation phase (expiration) with a flow rate and a flow direction associated with the flow rate, in which the amount of respiratory gas flowing toward the patient is lower than the amount of respiratory gas flowing away from the patient. The pressure and flow threshold values ​​are preferably provided directly to the control unit or, alternatively, indirectly with the assistance of the data storage device.

[0101] An alternative way of determining the situation of the interaction between the ventilator and the patient, in which a smaller amount of respiratory gas is delivered or flows from the ventilator to the patient via the inspiratory path of the connecting system than flows away from the patient via the expiratory path of the connecting system, is obtained for the control unit from the use of information from the ventilation process with a control of inspiration phases, expiration phases, volumes (V T ) and ventilation pressures (P insp , P exsp , PEEP).

[0102] The control unit is thus designed to determine when a situation of interaction between the ventilator and the patient exists in which a smaller amount of respiratory gas is conveyed or flows from the ventilator to the patient via the inspiratory path of the connecting system than flows away from the patient via the one expiratory path of the connecting system.

[0103] This situation corresponds to a state of expiration, i.e. a phase of the patient's exhalation, in which, due to a coughing event, an additional amount of exhaled respiratory gas is present as an at least temporary increase in the flow rate in the gas-carrying connection system and the pressure exceeding the predetermined pressure threshold was caused by the coughing event or the coughing fit.

[0104] According to the invention, the control unit is therefore further prepared and designed to determine situations in which the at least one flow rate measurement value exceeds the predetermined flow rate threshold value and the detected pressure measurement value exceeds the predetermined pressure threshold value as coughing events and, taking into account an evaluation criterion, to determine a state which indicates at least one coughing attack.

[0105] The control unit, in combination with the data storage device, is further designed to continuously record a plurality of flow rate measurement values ​​and a plurality of pressure measurement values ​​as elements of a data set in an analysis time interval.

[0106] The analysis time interval is updated by the control unit as a sliding time interval over the course of the recording, with the temporal progress of the recording, so that over time, the most recent values ​​of pressure and flow rate are included in the data set to be analyzed by the control unit, and the oldest values ​​of pressure and flow rate in the data set to be analyzed are no longer included in the control unit's analysis. Furthermore, the control unit is designed to provide a control signal at an interface, for example, for transmission to a data network (LAN, WLAN), which indicates the patient's coughing attack.The control unit is further configured to activate and / or deactivate the alarm unit to issue an alarm of a visual and / or acoustic warning or alarm indicating the condition that indicates a coughing attack of the patient.

[0107] The ventilator determines, by means of the control unit, the condition which indicates a coughing attack of the patient, wherein the control unit is designed to effect an initialization of an analysis time interval and a data set and, after the initialization of the analysis time interval and the data set, to repeatedly execute the following sequence of steps: - Recording of pneumatic and fluidic physical conditions with determination of pressure and flow rates as data set, - Determination of whether a situation of interaction between the ventilator and the patient with an increased airway pressure exists, based on a comparison of whether an exceedance of a comparison criterion indicating an increased airway pressure is given by the determined value of the airway pressure, - Determining whether a situation of interaction between the ventilator and the patient exists in which a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, based on a comparison of whether an exceedance of a comparison criterion indicating a flow rate and a flow direction is given by the determined value of the flow rate and by the determined flow direction, - Determination on the basis of at least one evaluation criterion which pneumatically / fluidically indicates physical conditions of pressure, flow rate and / or volume of an interaction between the ventilator and the patient, whether a condition exists in the analysis time interval which indicates at least one coughing attack, - Providing a control signal indicating the condition that indicates a coughing attack, - Updating the analysis time interval and data volume

[0108] The amount of data is selected and kept available in the data storage as an amount of storage space corresponding to the duration of the analysis time interval.

[0109] When initializing the analysis time interval and the data volume, the control unit maintains this amount of storage space in the data memory and sets the temporal starting point of the analysis time interval before the start of the continuous execution of the sequence of steps for determining conditions with coughing attacks.

[0110] The analysis time interval is updated by the control unit over the course of the recording as the recording progresses, resulting in a sliding time interval which is characterized in that the most recent values ​​of pressure and flow rate are included in the data set in the data memory provided for determining the condition that indicates at least one coughing attack, and the oldest values ​​of pressure and flow rate are no longer addressed in the data memory by the control unit or are no longer addressable by the control unit and are therefore no longer included by the control unit in the analysis of the data set for determining the condition that indicates at least one coughing attack.

[0111] When updating the analysis time interval and the data volume, the control unit updates the analysis time interval and the corresponding data volume by a predetermined time interval or a predetermined number of values ​​of pressure and flow rate over the course of the recording.

[0112] This is done, for example, by shifting the data within the data volume in the data memory or by changing an address pointer to memory areas in the data memory by the control unit by one or more sample values ​​of the pressure and flow rate values ​​over time.

[0113] In a preferred embodiment of the ventilation device, the at least one pressure sensor or a further pressure sensor for detecting and determining the pressure is arranged and designed on the connecting element (Y-piece), which is designed to transmit a signal of the pressure value to the control unit by means of suitable signal / data lines.

[0114] In a preferred embodiment of the ventilation device, the at least one pressure sensor or a further pressure sensor is arranged and designed to detect the pressure on the inspiratory connection system (ventilation tube), which is designed to transmit a signal of the pressure value to the control unit by means of suitable signal / data lines.

[0115] In a preferred embodiment of the ventilation device, the at least one pressure sensor or a further pressure sensor for detecting the pressure is arranged on the expiratory connection system (ventilation tube), which is designed to transmit a signal of the pressure value to the control unit by means of suitable signal / data lines.

[0116] In a preferred embodiment of the ventilator, at least one flow sensor is arranged on the patient connection path or on the connecting element (Y-piece) to detect flow rates and flow directions. This flow sensor is designed to transmit the flow rate values ​​to the control unit via suitable signal / data lines. The flow rate values ​​indicate at least the flow rates flowing away from the patient, and preferably also the flow rates flowing towards the patient. The control unit is designed to determine whether the ventilator is in a situation of interaction between the ventilator and the patient in which a smaller amount of respiratory gas is being delivered to the patient by the ventilator than is flowing away from the patient, based on the signal from the flow sensor arranged on the patient connection path or on the connecting element (Y-piece).

[0117] In a preferred embodiment of the ventilation device, at least one flow sensor or another flow sensor is arranged on the inspiratory connection system (ventilation tube), which is configured to transmit the flow rate values ​​to the control unit via suitable signal / data lines. The flow rate values ​​indicate the flow rates flowing to the patient.

[0118] In a preferred embodiment of the ventilation device, at least one flow sensor or another flow sensor is arranged on the expiratory connection system (ventilation tube), which is configured to transmit the flow rate values ​​to the control unit via suitable signal / data lines. The flow rate values ​​indicate the flow rates flowing away from the patient.

[0119] In a further preferred embodiment, the control unit is designed to determine whether the ventilator is in a situation of interaction between the ventilator and the patient in which a smaller amount of respiratory gas is delivered from the ventilator to the patient than flows away from the patient, on the basis of a difference between the signals of the flow sensor arranged in or on the expiratory path of the connection system and the flow sensor arranged in or on the inspiratory path of the connection system.

[0120] In a further preferred embodiment of the ventilator device, the control unit takes into account at least one piece of information from a control sequence of the ventilator device with regard to the current breathing phase or information with regard to a state of an expiratory valve or a control signal for such an expiratory valve in order to determine whether, due to the interaction of the ventilator device and the patient, a smaller amount of respiratory gas is delivered from the ventilator device to the patient than flows away from the patient, and thus an indication of conditions with coughing attacks is given.By controlling the expiratory valve during mechanical ventilation, for example, mandatory or assisted ventilation, the control unit ensures the continuous sequence of expiratory phases (exhalation) and inspiration phases (inhalation) based on the respiratory rate (RR) and the inspiration / expiration ratio (I:E ratio). Thus, in many situations, at least some information about the current breathing phase can be derived from the status and control of the expiratory valve.With such information about the valve status (closed, open, output level), it is possible for the control unit, particularly in the case of ventilation with mandatory ventilation modes, to verify from the control sequence whether a smaller amount of respiratory gas is being delivered from the medical device to the patient than is flowing away from the patient, i.e. whether there is an expiratory phase on the part of the medical device - which is then usually mandatory and specified by the medical device.

[0121] In a further embodiment, the control unit uses as a possible comparison criterion an increased airway pressure P AWindicated, a predetermined pressure threshold is selected. For example, a pressure value above a pressure threshold, such as 30 hPa ± 3 hPa, indicates elevated airway pressure for an adult patient. For example, a pressure value above a pressure threshold of 20 hPa ± 1 hPa indicates elevated airway pressure for an infant patient.

[0122] In a preferred embodiment, the control unit is designed to select a time range of 20 seconds to 60 seconds or a number of 2 to 6 consecutive breathing cycles as the analysis time interval.

[0123] In a preferred embodiment, the control unit is designed to apply a minimum number of coughing events, for example a number of at least 4 to 6 coughing events in the analysis time interval, as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack.

[0124] In a further preferred embodiment, the control unit is designed as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, in the analysis time interval a predetermined minimum number of coughing events, for example a number of 4 to 6 coughing events, based on increases in the airway pressure P AW above the predetermined pressure threshold.

[0125] The predetermined pressure threshold for determining cough events is preferably selected within a range of 30 hPa ± 3 hPa for adults, adolescents, or children, or within a range of 20 hPa ± 1 hPa for infants and / or toddlers. The control unit preferably uses a time range of 20 to 60 seconds or a number of 2 to 6 consecutive respiratory cycles as the analysis time interval.

[0126] In a further preferred embodiment, the control unit is designed to be at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, in the analysis time interval a predetermined minimum number of coughing events, for example an exceedance of a number of at least 2 to 6 coughing events, on the basis of increases in the flow rates V̇ exhaled by the patient. Patabove the predetermined flow rate threshold. The predetermined flow rate threshold for determining cough events is selected by the control unit in a preferred range of 90 l / min to 180 l / min. The control unit preferably uses a time range of 20 to 60 seconds or a number of 2 to 6 consecutive respiratory cycles as the analysis time interval.

[0127] In a preferred embodiment, the control unit is designed to use as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, i.e. events with respective increases in the airway pressure P AW above the predetermined pressure threshold, by forming a time integral of the increases in airway pressure P AWin the analysis time interval. The control unit evaluates the exceedance of a predetermined threshold value by the coughing events as an indication of the state of a coughing attack. This predetermined threshold value can be applied, for example, in units of pressure (hPa, mbar) or as a dimensionless numerical value. Preferably, a multiple, e.g., 3 to 5 times the pressure threshold value is selected. The control unit preferably uses a time range of 20 to 60 seconds or a number of 2 to 6 respiratory cycles as the analysis time interval.

[0128] In a preferred embodiment, the control unit is designed to apply, as at least one evaluation criterion for analyzing whether a condition exists that indicates a coughing attack, a volume that exceeds a volume threshold or a minimum amount of a flow rate in the analysis time interval, corresponding to a minimum volume that has flowed away from the patient due to coughing events in the analysis time interval. The predetermined minimum volume can be related to the tidal volume V Tor the patient's minute volume (MV). For example, an integral volume of 10% - 20% above the tidal volume or a sudden exceedance of the previously calculated minute volume by 5% to 10% can be selected as the volume threshold. Exceeding the predetermined minimum volume can also be determined by exceeding a predetermined volume threshold as a volume value, which, for example, corresponds to at least 3 to 5 times a typical tidal volume. With a typical tidal volume of 0.5 liters ± 0.2 liters, possible values ​​of approximately 1 liter to 3 liters result for both the minimum volume and the volume threshold.

[0129] In a further preferred embodiment, the control unit is designed to be at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, i.e. events with respective increases in the flow rates V̇ exhaled by the patient. Pat above the predetermined flow rate threshold, by forming a time integral of the increases in the flow rates exhaled by the patient V̇ Patto be applied in the analysis time interval. The control unit evaluates the exceedance of a predetermined volume threshold by the coughing events as an indication of the state of a coughing attack. The predetermined flow rate threshold for determining the coughing events is selected by the control unit in a preferred range of 90 l / min to 180 l / min. The predetermined volume threshold is preferably selected by the control unit with reference to a typical tidal volume. With a typical tidal volume of 0.5 liters ± 0.2 liters, possible values ​​of approximately 1 liter to 3 liters for the volume threshold result.

[0130] The control unit preferably uses a time range of 20 to 60 seconds or a number of 2 to 6 consecutive breathing cycles as the analysis time interval.

[0131] In a preferred embodiment, the control unit is designed to be at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, i.e. events with respective increases in the airway pressure P AWabove a predetermined pressure threshold, by forming a time integral of the increases in flow rates corresponding to the coughing events in the analysis time interval. The predetermined pressure threshold for determining the coughing events is preferably selected in a range of 30 hPa ± 3 hPa for adults, adolescents or children, or in a range of 20 hPa ± 1 hPa for infants and / or toddlers. The predetermined volume threshold is preferably selected by the control unit with reference to the tidal volume. With a typical tidal volume of 0.5 liters ± 0.2 liters, possible values ​​of approximately 1 liter to 3 liters result for the volume threshold. The control unit preferably uses a time range of 20 to 60 seconds or a number of 2 to 6 consecutive respiratory cycles as the analysis time interval.

[0132] In a preferred embodiment, the control signal provided by the control unit is forwarded from the alarm unit to an output unit. The output unit, preferably as part of the ventilator, is designed to forward the control signal, which indicates the state of coughing attacks during operation of the ventilator, directly or via an interface (WLAN, LAN, RS232, data bus, IrDA) to a device network in a data network (intranet, internet, PAN, WAN) and / or to an evaluation unit (monitoring or monitoring station, patient data management system).

[0133] In a preferred embodiment, the alarm unit is configured to output a message or notification and / or alert a condition indicating one or more coughing attacks by means of a visual and / or acoustic warning or alarm indicating this condition. Acoustic alarms can be issued, for example, via a sound element (loudspeaker, horn, voice output).

[0134] Visual alarms can be issued by the alarm unit, for example, via a screen (screen, touchscreen, tablet PC, smartphone), a light source (LED, LED), or in text form (LCD line, LED line, dot matrix display).

[0135] The applications of the evaluation criteria according to the list (a. - e.) with evaluation criteria in the previously described embodiments of the method for operating a ventilator and the ventilator with a determination of coughing attacks using the evaluation criteria according to the list (a. - e.) with evaluation criteria represent solutions according to the invention, both individually and in diverse combinations with one another, with regard to the design of the analysis time intervals and the predetermined threshold values ​​of pressure, flow rates, numbers of coughing events, volumes, minimum volumes, time integrals of pressure and / or flow rates, wherein adjustments in the selected and / or applied ranges of the threshold values ​​and the analysis time interval in combinations of these embodiments are also encompassed by the concept of the present invention.

[0136] The present invention will now be explained in more detail with the aid of the following figures and the associated descriptions of the figures without limiting the general inventive concept.

[0137] They show: Fig. 1 a schematic representation of a ventilator designed for mechanical ventilation, Fig. 2 Signal-time diagrams with events that are significant for coughing attacks

[0138] The Fig. 1 shows a schematic representation of a ventilation device suitable for mechanical ventilation in the form of a ventilator 1 with its essential elements.

[0139] The ventilator 1 has a control unit 27, which is preferably designed as an electronic controller, which is suitably designed and provided for controlling or regulating a gas mixing and dosing unit 23 with a dosing valve arrangement 25 arranged therein. Furthermore, measuring locations 15, 17, 19, 21 are shown within the ventilator 1. Downstream of the gas mixing and dosing unit 23, a measuring location for the inspiratory flow rate 15 and a measuring location for an inspiratory pressure 19 are arranged. Following these measuring locations 15, 19, an inspiration branch of a patent gas supply line 7 is arranged, via which the ventilator 1 supplies respiratory gases to the patient 3 during inspiration. Directly on the patient 3, outside 150 of the ventilator 1, but interacting with the ventilator 1, on a so-calledA measuring point for a patient flow rate 11 and a patient pressure 13 is arranged on the Y-piece, from which the patient 3 is connected to the ventilator 1 via a patient gas supply line 5, usually designed as an endo-tracheal tube, for the exchange of inhaled and exhaled air. As an alternative to the endo-tracheal tube, non-invasive elements for patient gas supply can also be used as the patient gas supply line 5, such as masks, for example nasal masks, on the Y-piece. From the Y-piece on the patient 3, the exhaled air of the patient 3 is returned to the ventilator 1 via an expiratory branch of the patient gas supply line 9.

[0140] In order to control the ventilator 1 for the purpose of ventilation control (respiratory cycle, ventilation frequency, expiratory ventilation pressure), the control unit 27 uses an expiratory valve 26, often also referred to as a “PEEP” valve, to adjust the pressure in the expiratory branch 9 and thus also the pressure present in the lungs of the patient 3 with the aid of a control signal 26'.

[0141] In addition, ventilation is controlled via the expiratory valve 26 in conjunction with the control unit 27 and the gas mixing and dosing unit 23 with the dosing valve arrangement 25 arranged therein, with cyclical alternations of inspiration and expiration phases (respiratory cycle, ventilation frequency). Within, or in the interior 160 of the ventilator 1, a measuring point for the expiratory flow rate 17 and a measuring point for an expiratory pressure 21 are arranged downstream of the expiratory branch 9 of the patient gas supply line 5.

[0142] In alternative and special designs of ventilators 1 which are specifically adapted to the application, such as emergency ventilators or home ventilators, as well as anaesthesia machines which, in addition to the components required for anaesthesia machines for anaesthesia, also have components for ventilation, the distribution of measuring locations and components (measuring probes, sensors) with regard to the elements inside 160 and outside 150 can deviate from the one described in this Fig.1. For example, the elements 15, 17, 19, 21 can be arranged outside 150 as well as inside 160 of the ventilator. Such configurations are encompassed by the concept of the invention, but are not shown for reasons of simplified representation and clarity. From these measuring locations 17, 21, the exhaled air of the patient 3 is discharged into the environment. The measuring locations 11, 13, 15, 17, 19, 21 and the sensors arranged at these measuring locations - in this Fig. 1 but not shown in detail for reasons of clarity - flow sensor, or flow rate sensor and pressure sensor are each connected to the control unit 27 via suitable signal and data lines 63, 67, 69, 83, 87, 89. In this Fig. 1 are one - in this Fig.1 not shown for reasons of clarity - flow measuring unit and a pressure measuring unit are designed as integrated into the control unit 27.

[0143] In addition to the flow measuring unit and the pressure measuring unit, the control unit 27 has suitably designed data processing and conversion units (signal amplification, signal filtering, A / D conversion), which in this schematic representation according to Fig.1 are not shown, as well as a processor unit 29 and a data storage unit 31 to design and carry out the ventilation process by and with the ventilator 1. The control unit 27 further evaluates the values ​​provided by the pressure and flow sensors to determine coughing attacks in an analysis time interval. In this analysis, the control unit 27 includes threshold values ​​of pressures, airway pressure, flow rates and volumes, and minimum numbers of pressure increases, flow rate increases, and volume increases in the analysis time interval. The control unit 27 can use one or more respiratory cycles 70 ( Fig. 2), one or more inspiration phases 72, 72', 72'', 72''' ( Fig. 2) or one or more expiratory phases 74, 74', 74" ( Fig. 2) apply.

[0144] The gases 33 required for ventilation, such as oxygen and air, are supplied by means of Fig. 1 not shown supply lines of the gas mixing and dosing unit 23 and converted there by the dosing valve arrangement 25 into a gas mixture which is suitable for ventilating the patient 3.

[0145] An alarm unit 40 with an optical signaling element 41 and an acoustic signaling element 42 is connected to the control unit 27 - wirelessly or wired - in order to signal alarm situations that may occur during operation of the ventilator 1 to the user. The connection is made in such a way that a control signal 131 is generated and provided by the control unit 27. The control signal 131 indicates whether a condition with one or more coughing attacks has occurred or is present in the analysis time interval. Furthermore, an output unit 44 is arranged on the alarm unit 40 for output in text or graphic form in order to output instructions, alarms, and messages to the user, for example a warning regarding a condition with coughing attacks during operation of the ventilator.In addition, an input unit 43 is connected to the control unit 27, via which the user can enter settings such as ventilation parameters, such as ventilation frequency, tidal volume, ventilation pressures (P. insp , PEEP) and associated alarm limits, such as maximum permissible airway pressure (P AW-high ), volume limits (MV Low ) on the ventilator 1, as well as settings that enable application-specific analysis to identify cough events, such as the entry of default values ​​for a predetermined minimum number of cough events, threshold values ​​for airway pressures, flow rates, and volumes, and the duration of the analysis time interval. Furthermore, the input unit 43 serves to acknowledge signaled alarm situations.

[0146] The Fig.Figure 2 shows signal curves of pressure and flow rate over time in the form of signal-time diagrams with events that are significant for coughing attacks.

[0147] In the Fig. 2 shows a pressure-time curve 100 and a flow rate-time curve 101. The pressure-time curve 100 represents the curve of pressure measurement values ​​99 (ordinate) with pressure threshold values ​​104 plotted against a time axis t (abscissa) 102. This pressure-time curve 100 represents the airway pressure P Aw on the ordinate.

[0148] The airway pressure P AW is the pressure that is the pressure for the patient 3 ( Fig. 1) during inhalation and exhalation, caused by the ventilator as well as by its own breathing activity, and is there as airway pressure P AW The flow rate time curve 101 represents a curve of flow measured values ​​V̇ Pat97 (ordinate) with flow threshold values ​​108, plotted against a time axis 102' (abscissa). The flow rate time curve 101 shows the patient flow rate V̇ Pat 97 with in patient 3 ( Fig. 1) inflowing flow quantities, as well as from the patient 3 ( Fig. 1) outflowing flow rates. The flow rates in patient 3 ( Fig. 1) The flow quantities flowing in are above the abscissa 102' in the positive part of the ordinate 97 those flow quantities which are supplied to the patient 3 ( Fig. 1) are supplied by the ventilator or the patient 3 ( Fig. 1) from the ventilator. The flow rates shown below the abscissa 102' in the negative part of the ordinate 97 are the flow rates received by patient 3 ( Fig. 1) away towards the environment or towards the ventilator during expiration phases by the patient 3 ( Fig. 1) are exhaled. The areas below the curves of the flow rate-time profile 101 are the volumes that result integrally for the exhaled flow rates and for the inhaled flow rates, respectively. In the time profiles 102, 102', several inspiration phases and several subsequent expiration phases are shown in a cyclic sequence. In the time profiles 102, 102', these inspiration and expiration phases are shown with the associated pressure measurements P AW 99 and associated flow measurements V̇ Pat 97 synchronized to each other in this Fig.2. In a first inhalation phase 72, followed by an exhalation phase 74, a breathing cycle 70 unaffected by disturbances or coughing is shown. This breathing cycle 70 shown - as well as the other breathing cycles shown - is divided into an inspiration phase 71 and an exhalation phase 73. The undisturbed breathing cycle 70 is followed by a further inspiration 72', which is followed by a further exhalation 74', in which pressure increases 77 occur. These pressure increases arise, for example, in relation to a first upper pressure limit value 55 as well as in relation to a pressure comparison curve 54. This pressure comparison curve 54, as it were, replicates the course of an undisturbed breathing cycle 70 with its decreasing pressure curve during the exhalation phase 74. The exhalation phase 74' is followed by a further inspiration phase 72''.

[0149] In this inspiration phase 72'', a pressure increase 77' results with a significant increase 105 of the airway pressure P AW99 above a second upper pressure limit 56, as well as further increases 77'', 105 in the subsequent expiration phase 74'' above a first upper pressure limit 55. This inspiration phase 72'' transitions into a subsequent expiration phase 74'', in which the increases in pressure 105 continue as exceedances of a first upper pressure limit 55. The first upper pressure limit 55 thus represents a pressure threshold 104 for expiration phases, whereas the second upper pressure limit 56 represents a pressure threshold 104 for the inhalation phases. An analysis of the pressure-time curve 100 with regard to exceedances of the pressure thresholds 104 makes it possible to detect coughing events. Thus, in the expiratory phase 74', a cough event is clearly visible in that the pressure threshold 104, 55 was exceeded by three individual cough events, which form a shorter cough attack 77.In the inspiration 72''' following the expiration phase 74'', it can be seen in the pressure signal curve 99 that the maximum value reached during inhalation is reduced compared to the maximum pressure value reached in the undisturbed respiratory cycle 70 in the inspiration phase 72. This is explained by the fact that the coughing attacks cause a volume deficit in the respiratory circuit and also in the lungs of patient 3 (. Fig. 1) which has to be filled with a quantity of air by this inspiration 72''', whereby the pressure increase of the inspiration is then delayed or even occurs with a reduced amplitude. This can also be clearly seen from the flow rate time curve 101. There it is visible that a volume compensation 61 occurs in the inspiration phase 72'''. The flow rate time curve 101 corresponds to the pressure time curve 100 in the Fig.2, where the events of pressure increases 77, 77', 77'' correspond to events of increases in the patient flow rate 78, 78' as well as decreases in the patient flow rate 79. To evaluate whether the determined pressure increases 105 are associated with coughing events 77, 77', 77'', lower flow limit values ​​59 as well as upper flow limit values ​​57, 58 can be applied to the flow measurement values ​​V̇ Pat 97 during the flow rate time curve 101. In the Fig. 2, the inspiration phases I1:72, I2:72', I3:72'' and I4:72''', as well as the expiration phases E1:74, E2:74' and E3:74'' are shown in the flow rate time curve 101 and the pressure time curve 100 in the same way in the time curve 102 corresponding and synchronized.

[0150] In the flow rate time curve 101, a flow rate comparison curve 53 is shown in part in the expiratory phase E2:74', which can be used in a similar way to the pressure comparison curve 54 shown at E2:74' in the pressure time curve 100 to distinguish coughing events as deviations from a normal breathing cycle 70, which is described by the inspiration phase I1:72 and the expiration phase E1:74. In addition to exceeding or falling below 108 threshold values ​​104, 55, 56, 57, 58, 59 or predetermined curve profiles 53, 54 by means of an amplitude comparison directly in the time course 102, 102', it is also possible to determine areas under the time courses 101, 102 as integrals and to compare the areas with an area-specific threshold value in order to determine coughing events and coughing attacks as a summary set of individual coughing events.Thus, the expiratory pressure integrals 48 in the pressure-time curve 100 indicate a coughing attack 77. Individual, discrete pressure increases 105, such as in the inspiration phase I3, can also be used as the integral area of ​​an inspiratory pressure integral 47 to define a coughing attack 77'. Similarly, the flow rate-time curve 101 can also be determined based on the flow measurement values ​​V̇. Pat97 in the signal curve, an integral is formed under the flow rate time curve 101. For example, in the expiratory increase of the patient flow rate 78 in the expiration phase 74', an expiratory flow rate integral 52 is shown. This flow rate integral 52 corresponds, as it were, to an exhaled cough volume. The same applies to the flow rate integral 52 in the expiration phase 74'' over time 102'. In the inspiration phase 72'', corresponding to the inspiratory reduction of the patient flow rate 79, an inspiratory flow rate integral 51 is shown as an example, which is represented as a flow rate which is expressed as a volume during the inspiration period by the patient 3 ( Fig. 1) contrary to the ventilator 1 ( Fig. 1) performed ventilation. This in the inspiration from patient 3 ( Fig.1) The flow rate flowing away results in the inspiratory flow rate integral as a cough volume, which causes a pressure increase 105 in the inspiration phase 72'' and is characteristic of a coughing attack or part of a coughing attack. In the inspiration phase 72''', an inspiratory flow difference 61 is shown in the flow rate time curve 101, which is clearly visible as an increase compared to the first upper flow limit value 57.

[0151] This increase in the flow rate results in a volume deficiency compensation as a refill volume 45, which results from the patient 3 ( Fig.1) during the preceding expiration phase 74'', more volume has been exhaled from his lungs than was supplied to the lungs in the previous breathing cycles. Exceeding the refill volume 45 by a predetermined value or exceeding the inspiratory flow difference or the volume flow compensation after a coughing attack 61 above a second upper flow limit 58 can be considered as an indication of a previous coughing attack 77, 77', 77''. These previously described methods of identifying distinctive signals as coughing events in the flow rate time curve 101, as well as in the pressure time curve 100, as well as in combination of the two time curves 100, 101, and of characterizing a large number of coughing events or a certain cough volume as coughing attacks, are Fig.2 in time courses 102, 102' are shown as examples. The shown course corresponds to pressure measured values ​​99 and flow measured values ​​V̇ Pat 97 merely fictitious and analytically determined relationships, which in the implementation of a real ventilation are still very much influenced by the choice of ventilation parameters: ventilation frequency (RR), inspiration to expiration ratio (I:E ratio), positive end-expiratory pressure (PEEP), tidal volume (V T ) and other parameters for fine-tuning the ventilation may appear differently. In this Fig.2, pressure-controlled ventilation was assumed; in volume-controlled ventilation, similar situations arise with partially different courses of the pressure-time curve 100 and the flow rate-time curve 101. Further influencing variables are given by further setting parameters such as trigger thresholds for detecting respiratory activities when using supportive ventilation modes. LIST OF REFERENCE SYMBOLS 1 ventilator, ventilation device 3 patients 5 Patient gas supply line 7 Inspiratory branch of the patient gas supply line 9 Expiratory branch of the patient gas supply line 11 Patient flow measurement location, Y-piece, connecting element 13 Measurement location for patient pressure 15 Measurement location of the inspiratory flow rate 17 Measurement location of expiratory flow rate 19 inspiratory pressure, measurement location 21 expiratory pressure, measurement location 23 Gas mixing and dosing unit 25 Dosing valve arrangement 26 Expiratory valve 26' Control signal for the expiratory valve 26 27 Control unit, electronic control 29 Processor unit 31 Data storage unit 40 Alarm unit, alarm output 41 optical signaling element 42 acoustic signaling element 43 Input unit 44 Output unit for text output, screen 45 refill volume 47 inspiratory pressure integrals 48 expiratory pressure integrals 51 inspiratory flow rate integrals 52 expiratory flow rate integrals 53 Flow rate comparison curve 54 Pressure comparison curve 55 first upper pressure limit 56 second upper pressure limit 57 first upper flow limit 58 second upper flow limit 59 lower flow limit 61 inspiratory flow difference, volume compensation after coughing attack 63, 67, 69 Signal / data lines of the pressure measuring points 70 breathing cycles 71 Inspiration phase duration T insp 72, 72', 72'', 72''' Time intervals with inspiration 73 Expiratory phase duration T exsp 74, 74', 74'' Time intervals with exhalation (expiration) 77, 77', 77'' Increases in pressure 78, 78' expiratory increases in patient flow rate 79 inspiratory reduction patient flow rate 83, 87, 89 Signal / data lines of the flow measuring points 97 Flow signal curve, flow measured values, (Y-axis, ordinate) 99 Pressure signal curve, pressure measured values, (Y-axis, ordinate) 100 Pressure-time history 101 Flow rate time curve 102, 102' Time axis t (X-axis, abscissa) 104 Pressure threshold 105 Increases in airway pressure (P AW ) 108 Flow rate threshold 131 Control signal 150 components located outside the device 160 components arranged within the device

Claims

[1] Method for operating a ventilator (1) with a determination of coughing attacks, wherein the ventilator (1) is designed to process sensor signals (97, 99) of the ventilator (1) provided by sensors (11, 13, 15, 17, 19, 21), wherein the sensor signals (97, 99) indicate pneumatic and fluidic physical states of a respiratory gas in a gas-conducting connection system (5, 7, 9) which is connected and coupled to the ventilator (1) and to a patient (3) in a gas-conducting manner and is designed to transport gases from and to the patient (3), from which values of an airway pressure P present in the gas-conducting connection system (5, 7, 9) AW (99) and a flow rate V̇ Pat (97), and the flow rate (97) in the gas-carrying connection system (5, 7, 9) can be determined, after initializing an analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and a data set, the following sequence of steps is repeatedly executed: - Recording of pneumatic and fluidic physical conditions with determination of values of pressure (99), flow rates (97) and flow directions as a data set, - Determination of whether a situation of interaction between the ventilator (1) and the patient (3) with an increased airway pressure P AW is given, on the basis of a comparison, whether an exceedance of a comparison criterion indicating an increased airway pressure by the determined value (99) of the airway pressure P AW is given, - Determining whether a situation of interaction between the ventilator (1) and the patient (3) exists in which a smaller amount of respiratory gas is delivered from the ventilator (1) to the patient (3) than flows away from the patient (3), on the basis of a comparison as to whether an exceedance of a comparison criterion indicating a flow rate and a flow direction by the determined value (97) of the flow rate V̇ Pat and is given by the specific flow direction, - Determining, on the basis of at least one evaluation criterion which pneumatically / fluidically indicates physical states of pressure, flow rate and / or volume of an interaction between the ventilator (1) and the patient (3), whether a state exists in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') which indicates at least one coughing attack, - providing a control signal (131) indicating the condition indicating a coughing attack, - Update of the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and the data set. [2] Method according to claim 1, wherein the determination of the airway pressure P AW (99) based on values (99) of at least one pressure sensor (13, 19, 21) for determining the airway pressure P Aw takes place, wherein the at least one pressure sensor (13, 19, 21) is arranged on the patient connection path (5) or on the connection system (11) and / or on the inspiratory connection system (7) and / or on the expiratory connection system (9). [3] Method according to claim 1, wherein the situation of the interaction of the ventilator (1) and the patient (3), in which a smaller amount of respiratory gas is delivered from the ventilator (1) to the patient (3) than flows away from the patient (3), is determined on the basis of values of at least one flow sensor (11, 15, 17), wherein the at least one flow sensor (11, 15, 17) is arranged on the patient connection path (5) or on the connection system (11) and / or on the inspiratory connection system (7) and / or on the expiratory connection system (9). [4] Method according to claim 1, wherein, for determining the situation of the interaction between the ventilator (1) and the patient (3), in which a smaller amount of respiratory gas is delivered from the ventilator (1) to the patient (3) than flows away from the patient (3), information from a control sequence of the ventilator (1) with regard to the current breathing phase is taken into account or information with regard to a state of an expiratory valve (26) or a control signal (26') for such an expiratory valve (26) is also taken into account. [5] Method according to one of the preceding method claims, wherein a number of 20 seconds to 40 seconds is selected as the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') or a number of 2 to 6 consecutive breathing cycles (70) is selected as the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [6] Method according to one of the preceding method claims, wherein a comparison with a predetermined minimum number (43) of coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') is used as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack. [7] Method according to one of the preceding method claims, wherein as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') a comparison with a predetermined minimum number (43) of coughing events on the basis of increases (77, 77', 77'', 105) in the airway pressure P AW above the predetermined pressure threshold (104). [8] Method according to one of the preceding method claims, wherein as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') a comparison with a predetermined minimum number of coughing events, on the basis of increases (78, 78') in the flow rates V̇ exhaled by the patient (3) Pat (97) above the predetermined flow rate threshold value (108). [9] Method according to one of the preceding method claims, wherein as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, by means of forming a time integral (47) of increases (105) of the airway pressure P AW in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [10] Method according to one of the preceding method claims, wherein as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a minimum amount of a flow rate in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''), corresponding to a minimum volume (52) which has flowed away from the patient (3) due to coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''), is used. [11] Method according to one of the preceding method claims, wherein as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, by means of forming a time integral (52) of the increases in the flow rates V̇ exhaled by the patient (3) Pat (97) is applied in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [12] Method according to one of the preceding method claims, wherein as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events is used by forming a time integral (51, 52) of the increases in the flow rates corresponding to the coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [13] Ventilation device (1) - with a connection system (5, 7, 9) designed to transport respiratory gases, - with a pressure measuring unit, - with a flow measuring unit, - with a control unit (27) and - with an alarm unit (40), - wherein the connection system (5, 7, 9) has an expiratory path (9) which is designed and provided for the continuation of an expiratory amount of respiratory gas from the patient (3), - wherein the connection system (5, 7, 9) has an inspiratory path (7) which is designed and provided for supplying an inspiratory amount of respiratory gas to the ventilation device (1) to the patient (3), - wherein the connection system (5, 7, 9) has a patient connection path (5) which is designed and provided for supplying the inspiratory amount of respiratory gas from the ventilator (1) to the patient (3) and for supplying the expiratory amount of respiratory gas from the patient (3), - wherein the expiratory path (9) and the inspiratory path (7) are connected to each other and to the patient connection path (5) by means of a connecting element (11), - wherein the flow measuring unit comprises at least one flow sensor (11, 15, 17) which is arranged in or on the connection system (5, 7, 9) or in or on the ventilation device (1) and is provided to measure at least one flow rate measurement value V̇ Pat (97) a quantity of respiratory gas and a flow direction of the respiratory gas associated with the flow rate measurement value (97), which flow direction flows away from the patient (3) in the connection system (5, 7, 9) or flows from the ventilator (1) to the patient (3), and wherein the flow measuring unit is designed to measure this at least one flow rate measurement value V̇ Pat (97) and the associated flow direction of the control unit (27), - wherein the pressure measuring unit comprises at least one pressure sensor (13, 19, 21) which is arranged in or on the ventilation device (1) or the connection system (5, 7, 9) and is provided to detect a pressure measurement value (99) of a pressure which is present in the connection system (5, 7, 9), and wherein the pressure measuring unit is designed to transmit this at least one pressure measurement value to the control unit (27) as an airway pressure P AW (99) to provide - wherein the control unit (27) is designed to effect an initialization of an analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and a data set and, after the initialization of an analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and the data set, to repeatedly execute the following sequence of steps: - Recording of pneumatic and fluidic physical conditions with determination of values of pressure (99) and flow rates (97) as a data set, - Determining whether a situation of interaction between the ventilator (1) and the patient (3) with an increased airway pressure exists, based on a comparison as to whether an exceedance of a comparison criterion indicating an increased airway pressure by the determined value (99) of the airway pressure P AW is given, - Determining whether a situation of interaction between the ventilator (1) and the patient (3) exists in which a smaller amount of respiratory gas is delivered from the ventilator (1) to the patient (3) than flows away from the patient (3), on the basis of a comparison as to whether an exceedance of a comparison criterion indicating a flow rate and a flow direction by the determined value V̇ Pat (97) the flow rate and the specific flow direction, - Determining, on the basis of at least one evaluation criterion which pneumatically / fluidically indicates physical states of pressure, flow rate and / or volume of an interaction between the ventilator (1) and the patient (3), whether a state exists in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') which indicates at least one coughing attack, - providing a control signal (131) indicating the condition indicating a coughing attack, - Update of the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') and the data set. [14] Ventilation device (1) according to claim 13, wherein the at least one pressure sensor (13, 19, 21) is configured to detect the pressure (99) - is arranged and formed on the patient connection path (5) or on the connecting element (11) - and / or is arranged and formed on the inspiratory path (7) - and / or is arranged and formed on the expiratory path (9) and wherein the at least one pressure sensor (13, 19, 21) is designed to transmit signals of the pressure measurement values (99) to the control unit (27) by means of suitable signal / data lines (63, 67, 69). [15] Ventilation device (1) according to claim 13, wherein the at least one flow sensor (11, 15, 17) is configured to detect flow rates (97) at - is arranged and formed on the patient connection path (5) or on the connecting element (11) - and / or is arranged and formed on the inspiratory path (7) - and / or is arranged and formed on the expiratory path (9) and wherein the at least one flow sensor (11, 15, 17) is designed to transmit signals of the flow rate measurement values (97) to the control unit (27) by means of suitable signal / data lines (83, 87, 89). [16] Ventilation device (1) according to claim 15, wherein the control unit (27) is designed to determine whether a situation of interaction between the ventilation device (1) and the patient (3) exists in which a smaller amount of respiratory gas is delivered from the ventilation device (1) to the patient (3) than flows away from the patient (3), on the basis of a difference between the signals of the flow sensor (21) arranged in or on the expiratory path (9) of the connection system (5, 7, 9) and the flow sensor (14) arranged in or on the inspiratory path (7) of the connection system (5, 7, 9). [17] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) for determining the situation of the interaction of the ventilation device (1) and the patient (3), in which a smaller amount of respiratory gas is delivered from the ventilation device (1) to the patient (3) than flows away from the patient (3), takes into account information from a sequence of the control of the ventilation device (1) with regard to the current breathing phase or information with regard to a state of an expiratory valve (26) or a control signal (26') for such an expiratory valve (26). [18] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses a number of 2 to 6 consecutive breathing cycles (70) or a number of 20 seconds to 60 seconds as the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [19] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses a comparison with a predetermined minimum number of coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74'') as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack. [20] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses, as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a comparison with a predetermined minimum number of coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''), on the basis of increases (105) in the airway pressure P Aw (99) above the predetermined pressure threshold (104). [21] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses, as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a comparison with a predetermined minimum number of coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''), on the basis of increases (78, 78') in the flow rates V̇ exhaled by the patient Pat (97) above the predetermined flow rate threshold value (108). [22] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, by means of forming a time integral (47, 48) of the increases (77, 77', 77'', 105) of the airway pressure P AW(99) is applied in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [23] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses, as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a minimum quantity (108) of a flow rate (97) in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''), corresponding to a minimum volume (52) which has flowed away from the patient (3) due to coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [24] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events, by means of forming a time integral (52) of the increases in the flow rates V̇ exhaled by the patient (3) Pat (97) is applied in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [25] Ventilation device (1) according to one of the preceding device claims, wherein the control unit (27) uses as at least one evaluation criterion for analyzing whether a condition exists which indicates a coughing attack, a summary effect of individual coughing events with respective increases (77, 77' 77'', 105) of the airway pressure P AW(99), by forming a time integral (51, 52) of the increases (78, 78') in the flow rates corresponding to the coughing events in the analysis time interval (70, 72, 74, 72', 74', 72'', 74''). [26] Ventilation device (1) according to one of the preceding device claims, wherein the control signal (131) indicating the state of coughing attacks during operation of the ventilation device (1) is passed on by means of an alarm unit (40) directly or by means of an interface to a device network in a data network and / or to an output unit (44). [27] Ventilation device (1) according to one of the preceding device claims, wherein the alarm unit (40) is designed to output a message or an indication on the output unit (44) and / or to alert a condition which indicates one or more coughing attacks by means of a visual and / or acoustic warning or alarm (41, 42) indicating this condition.

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