Apparatus and method for controlling gas flow

Abstract

To provide a method and a device for efficient regulation of a gas composition.SOLUTION: Provided herein is a method for regulating a gas flow of at least one first gas to be admixed to at least one second gas. The method comprises at least one method for the control of a gas valve. At least one manipulated variable for the control of the gas valve is determined from at least one correction regulator component and at least one feedforward component, the input variable of the feedforward component being a predicted gas flow setpoint value of the first gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control unit and a method for controlling a gas flow of a first gas for mixing with a second gas. [Background technology]

[0002] In many devices, particularly medical devices, two gases are intended to be mixed with each other. In some cases, it may happen that the second gas is a gas mixture that already contains a certain concentration of the first gas. Typically, the flow rate, and therefore the amount, of at least one of the gases (or gas mixture) to be mixed is controlled or generated by a valve. In this case, a control loop or control circuit is usually used, which controls the valve based on the concentration of the first gas, e.g., oxygen, in the resulting mixture. However, measuring the oxygen concentration is usually inaccurate and slow. This can cause problems, for example, in delivering the right amount of oxygen to the patient at the right time. There is also a delay in setting the correct concentration. Summary of the Invention [Problem to be solved by the invention]

[0003] It is therefore an object of the present invention to provide a method and device for efficiently adjusting the gas composition. [Means for solving the problem]

[0004] The present invention relates to a control unit for a breathing apparatus, the control unit being configured and arranged to perform a method for controlling a gas flow rate of at least one first gas for mixing with at least one second gas, the method comprising at least one method step of controlling a gas valve, and at least one method step for controlling the gas valve. Operation amount is determined (specified) from at least one corrective adjustment component and at least one feedforward component, and the control unit is characterized in that an input quantity (input variable) of the feedforward component is a predicted gas flow rate schedule value (predicted gas flow rate schedule value) of the first gas.

[0005] In some embodiments, the control unit is characterized in that the method further comprises a first method step of total flow rate prediction, a second method step of flow rate scaling, and a third method step of determining a predicted gas flow rate target value (predicted gas flow rate reference value) and / or a scaled predicted gas flow rate target value.

[0006] In some embodiments, the control unit is characterized in that in a first method step, a predicted total flow target value (predicted total flow reference value) of a gas mixture of at least two gases is determined starting from a set pressure value (set pressure value) and a ventilation situation. In some embodiments, the control unit is characterized in that the first method step includes a patient flow model, the set pressure value and the ventilation situation are included in at least a part of the patient flow model, and the results of the patient flow model and at least a part of the ventilation situation are included in the calculation of the predicted total flow target value. In some embodiments, the control unit is characterized in that in the first method step, an initial value of the patient flow model is determined by a patient model from the ventilation situation, in particular in the form of an RC surrogate model.

[0007] In some embodiments, the control unit is characterized in that in a second method step, a scaled predicted total flow rate and / or a scaled predicted gas flow rate are calculated from the predicted total flow rate alone or from the predicted total flow rate together with the predicted gas flow rate. In some embodiments, the control unit is characterized in that in the second method step, a scaled predicted total flow rate and / or a scaled predicted gas flow rate are calculated from the predicted gas flow rate. In some embodiments, the control unit is characterized in that the second method step includes scaling, where separate scaling factors and / or scaling functions are determined for inspiration and expiration, and the control unit switches between the scaling factors and / or scaling functions depending on inspiration or expiration. In some embodiments, the control unit is characterized in that to determine the scaling factor and / or scaling function, at least one comparison between a planned inspiration volume or expiration volume and an actually applied inspiration volume or expiration volume is taken into account.

[0008] In some embodiments, the control unit is characterized in that the third method step includes calculating a predicted gas flow rate budget from the predicted total flow rate budget. In some embodiments, the control unit is characterized in that the third method step includes determining an average concentration mcO2% of the first gas in the second gas, where the determination of the average concentration mcO2% of the first gas also incorporates a rebreathing volume (volume of exhaled air that is re-inhaled). In some embodiments, the control unit is characterized in that the third method step includes incorporating the determined average concentration mcO2% of the first gas into the determination of the predicted gas flow rate budget.

[0009] In some embodiments, the control unit comprises a Operation amount The input amount of the feedforward component for determining ? is a scaled predicted gas flow schedule, optionally taking into account rebreathing volume.

[0010] In some embodiments, the control unit is characterized in that the input amount of the correction adjustment component includes at least one parameter representing the deviation (deviation) of the actual gas flow rate determined by at least one flow rate sensor from a predetermined target gas flow rate value (reference gas flow rate value).

[0011] In some embodiments, the control unit may further comprise a step of controlling the gas valve when the gas flow rate value corresponds to the predetermined gas flow rate value. Operation amount The correction adjustment component of the above is zero.

[0012] In some embodiments, the control unit is characterized in that the first gas is oxygen and the second gas is ambient air or compressed / pressurized air or a gas mixture from ambient air, and / or compressed / pressurized air and / or at least partially rebreathed respiratory gas.

[0013] In some embodiments, the control unit is configured to calculate a rebreathing volume based on measurement data of the at least one flow sensor.

[0014] In some embodiments, the control unit is characterized in that in a first method step, a predicted total flow plan is calculated from at least one ventilation state, a set pressure value and at least partially by a patient flow model; in a second method step, a scaled predicted total flow plan is determined from the predicted total flow plan and the inspiration data and the expiration data by scaling, the scaling being adapted to the respective respiratory phase; in a third method step, a scaled predicted gas flow plan is determined from the scaled predicted total flow plan and the mean concentration of the first gas, mcO2%, determined using the rebreathing volume; and in a fourth method step, the input amount of the feedforward component is the scaled predicted gas flow plan.

[0015] The invention also relates to a breathing apparatus comprising at least one control unit as described above.

[0016] The present invention also relates to a method for controlling a gas flow of at least one first gas for mixing with at least one second gas, the method comprising at least one method step of controlling a gas valve, the method comprising at least one method step of controlling the gas valve. Operation amount is determined from at least one corrective adjustment component and at least one feedforward component, wherein the input amount of the feedforward component is a predicted gas flow rate schedule for the first gas.

[0017] In some embodiments, the method is characterized by comprising at least one method step of total flow prediction, method steps for flow scaling, method steps for determining predicted gas flow rate schedule values ​​and / or scaled predicted gas flow rate schedule values, and method steps for controlling the gas valves.

[0018] In some embodiments, the method includes at least one method step of total flow rate prediction, characterized in that a predicted total flow rate schedule value of a gas mixture of at least two gases is determined starting from a set pressure value and a ventilation situation.

[0019] In some embodiments, the method is characterized in that the method step of total flow prediction includes a patient flow model, the set pressure value and ventilation status are at least partially included in the patient flow model, and the results of the patient flow model and at least a portion of the ventilation status are included in the calculation of the predicted total flow schedule value.

[0020] In some embodiments, the method is characterized in that in the method step, an initial value of the patient flow model is determined from the ventilation situation by a patient model, In some embodiments, the method is characterized in that in the method step, the patient model is an RC surrogate model.

[0021] In some embodiments, the method includes at least one method step for flow rate scaling, characterized in that in the method step for flow rate scaling, a scaled predicted total flow rate forecast value and / or a scaled predicted gas flow rate forecast value are calculated from the predicted total flow rate forecast value and / or the predicted gas flow rate forecast value.

[0022] In some embodiments, the method is characterized in that the method steps comprise scaling, and separate scaling factors and / or scaling functions are determined for inspiration and expiration, and a switch is used to switch between the scaling factors and / or scaling functions depending on inspiration or expiration. In some embodiments, the method is characterized in that for determining the scaling factor and / or scaling function, at least one comparison between a planned inspiration volume or expiration volume and an actually applied inspiration volume or expiration volume is taken into account.

[0023] In some embodiments, the method is characterized in that the method step for determining the predicted gas flow budget comprises calculating the predicted gas flow budget from the predicted total flow budget.

[0024] In some embodiments, the method is characterized in that a method step includes determining an average concentration mcO2% of the first gas in the second gas, and the determination of the average concentration mcO2% of the first gas also incorporates a rebreathing volume. In some embodiments, the method is characterized in that a method step includes incorporating the determined average concentration mcO2% of the first gas into determining a predicted gas flow budget.

[0025] In some embodiments, the method is characterized in that in a method step, a scaled predicted gas flow rate budget is determined.

[0026] In some embodiments, the method further comprises, in the method step, Operation amountThe input amount of the feedforward component for determining is a scaled predicted gas flow schedule, and optionally takes into account the rebreathing volume V_Rueck.

[0027] In some embodiments, the method is characterized in that the input amount of the corrective adjustment component includes at least one parameter representative of a deviation of the gas flow value from a predetermined gas flow value.

[0028] In some embodiments, the method further comprises controlling the gas valve when the gas flow rate value corresponds to the predetermined gas flow rate value. Operation amount The correction adjustment component of the above is zero.

[0029] In some embodiments, the method is characterized in that the method steps for flow rate scaling and for determining the predicted gas flow rate forecast value are interchangeable, and in the method steps, if a method step follows a method step, a predicted gas flow rate forecast value is calculated, or if a method step follows a method step, a scaled predicted gas flow rate forecast value is determined.

[0030] In some embodiments, the method is characterized in that the first gas is oxygen and the second gas is ambient air or compressed / pressurized air, and alternatively a gas mixture from ambient air and / or compressed / pressurized air and / or at least partially rebreathed respiratory gas.

[0031] The present invention also relates to a method for controlling a gas flow rate of at least one first gas for mixing with at least one second gas, the method comprising at least one method step of controlling a gas valve, the method comprising at least one method step of controlling the gas valve. Operation amount is determined from at least one corrective adjustment component and at least one feedforward component. a. in a first method step, a predicted total flow budget is calculated from at least one ventilation state, a set pressure value, and at least in part by a patient flow model; b. in a second method step, a scaled predicted total flow schedule is determined from the predicted total flow schedule and the inspiration and expiration data by scaling, and the scaling is adapted to each respiratory phase; c. In a third method step, a scaled predicted gas flow schedule is determined from the scaled predicted total flow schedule and the mean concentration of the first gas, mcO2%, determined using the rebreathing volume V_Rueck; d. In the method step of controlling the gas valve, the input quantity of the feedforward component is the scaled predicted gas flow rate schedule value from the third method step; It is characterized by:

[0032] The control unit is configured and arranged to perform a method for controlling a gas flow of at least one first gas for mixing with at least one second gas, the method comprising at least one method step of controlling a gas valve, and at least one method step for controlling the gas valve. Operation amount is determined from at least one corrective adjustment component and at least one feedforward component, and the control unit is characterized in that an input amount of the feedforward component is a predicted gas flow rate schedule value of the first gas.

[0033] In some embodiments, the control unit is characterized in that the control unit comprises a calculation unit, the calculation unit configured and arranged to determine a predicted gas flow rate forecast value for the first gas from the predicted total flow rate forecast value.

[0034] In some embodiments, the control unit is characterized in that the calculation unit is configured and arranged to determine a predicted total flow schedule from the set pressure value and the ventilation situation.

[0035] The invention also relates to a breathing apparatus, comprising a gas valve and a control unit, the control unit being configured and arranged to carry out the method described above.

[0036] In some embodiments, the breathing apparatus is characterized in that the breathing apparatus comprises at least one flow sensor, and the control unit is configured and arranged to calculate the rebreathing volume V_Rueck based on measurement data of the at least one flow sensor.

[0037] In some embodiments, the breathing apparatus further comprises a control unit for controlling the gas valve based on a comparison between a predetermined gas flow rate target value and a gas flow rate value of the first gas determined by the flow sensor. Operation amount The method is characterized in that the method is configured and formed to determine a corrective adjustment component of

[0038] In some embodiments, the respiratory apparatus comprises a control unit Operation amount configured and configured to control the gas valve based on Operation amount The control method is characterized in that the control method comprises a feedforward component and a correction adjustment component, and the feedforward component has a predicted gas flow rate schedule value of the first gas as an input amount.

[0039] In some embodiments the respiratory apparatus is characterized in that the respiratory apparatus and / or the control unit comprises a calculation unit, the calculation unit configured and arranged to determine a predicted gas flow rate forecast for the first gas from the predicted total flow rate forecast.

[0040] In some embodiments the breathing apparatus is characterized in that the calculation unit is arranged to determine a predicted total flow budget from the set pressure value and the ventilation situation.

[0041] In some embodiments the respiratory apparatus is characterized in that the calculation unit is configured and arranged to incorporate a patient flow model into the determination of the predicted total flow budget.

[0042] In some embodiments the breathing apparatus is characterized in that the calculation unit is configured and arranged to calculate a scaled predicted total flow rate forecast and / or a scaled predicted gas flow rate forecast from the predicted total flow rate forecast.

[0043] In some embodiments the respiratory apparatus is characterized in that the calculation unit is configured and arranged to scale the predicted total flow budget depending on the respiratory phase.

[0044] In some embodiments, the respiratory device is characterized in that the calculation unit also incorporates the mean ambient air concentration of the first gas into the calculation of the scaled predicted gas flow rate value, the mean ambient air concentration of the first gas being determined, inter alia, by the rebreathing volume V_Rueck.

[0045] In some embodiments, the breathing apparatus is characterized in that the calculation unit is configured and designed to calculate the rebreathing volume V_Rueck on the basis of measurement data from the at least one flow sensor.

[0046] In some embodiments, the breathing apparatus further comprises a calculation unit for calculating a gas flow rate for controlling the gas valve from a comparison of a predetermined gas flow rate schedule value and a gas flow rate value of the first gas determined by the flow sensor. Operation amount The method is characterized in that the method is configured and formed to determine a corrective adjustment component of

[0047] In some embodiments, the control unit is configured and arranged to perform a method for controlling a gas flow rate of at least one first gas for mixing with at least one second gas, the method comprising at least one method step of controlling a gas valve, and at least one method step for controlling the gas valve. Operation amount is determined from at least one corrective adjustment component and at least one feedforward component, and the control unit a. in a first method step, a predicted total flow budget is calculated from at least one ventilation state, a set pressure value, and at least in part by a patient flow model; b. in a second method step, a scaled predicted total flow schedule is determined from the total flow schedule and the inspiration and expiration data by scaling, and the scaling is adapted to each respiratory phase; c. In a third method step, a scaled predicted gas flow schedule is determined from the scaled predicted total flow schedule and the mean concentration of the first gas, mcO2%, determined using the rebreathing volume V_Rueck; d. The method step is a fourth method step, and the input amount of the feedforward component is the scaled predicted gas flow rate schedule value from the third method step.

[0048] The proposed control, proposed method, and proposed breathing apparatus are designed to achieve a total concentration of a particular gas in a gas mixture, where a first gas is mixed with a second gas or gas mixture, and the second gas / gas mixture contains a concentration of the first gas. This is achieved by appropriately controlling a gas valve that generates a flow rate of the first gas mixed with the second gas. In some embodiments, it is contemplated that the gas mixture of the first gas and the second gas may at least partially backflow (reflux). In this case, the concentration of the first gas in the backflowing gas is also taken into account, and the control of the gas valve for the flow rate of the first gas can be adapted accordingly.

[0049] It is to be noted that the features individually recited in the claims can be combined with one another in any and technically meaningful manner to represent further embodiments of the invention. The following description characterizes the invention and makes it clearer, particularly in conjunction with the figures.

[0050] It is further noted that the conjunction "and / or" used herein between two features linking them to one another should always be interpreted in such a way that in a first embodiment of the subject matter according to the invention, only the first feature can be present, in a second embodiment, only the second feature can be present, and in a third embodiment, both the first and second features can be present.

[0051] A respiratory device (ventilator) is understood to be any device that assists the natural breathing of a user or patient, takes over the breathing of a user or organism (e.g., a patient and / or a newborn and / or a premature infant), and / or is used for respiratory therapy and / or otherwise affects the breathing of a user or patient. This includes, but is not limited to, for example, CPAP and BiLevel devices, anesthesia or anesthesiology devices, respiratory therapy devices, (clinical, non-clinical, or emergency) breathing devices, high-flow therapy devices, and cough assist devices. A respiratory device can also be understood as a diagnostic device for ventilation. Diagnostic devices can generally be used to detect medical and / or respiratory-related parameters of an organism. This includes devices that can detect and optionally process patient medical parameters related to breathing in combination with or solely to breathing.

[0052] Unless otherwise specified, a patient interface can be understood to mean any peripheral device intended for interaction between a breathing apparatus and a living organism, and vice versa, in particular for therapeutic, ventilatory, and / or diagnostic purposes. In particular, a patient interface can be understood to mean a mask of the breathing apparatus or a mask connected to the breathing apparatus. This mask can be a full-face mask, i.e., a mask covering the nose and mouth, or a nasal mask, i.e., a mask covering only the nose. Tracheal hoses or tracheal cannulas, as well as so-called nasal cannulas, can also be used as masks or patient interfaces. In many cases, the patient interface can also be a simple mouthpiece, e.g., a tube, through which the living organism at least exhales and / or inhales.

[0053] The connection between the patient interface and the breathing apparatus can be made via a number of different connection or hose systems. For example, a leak system can be provided that allows exhaled breathing gas to escape through an intentional leak in the patient interface and / or breathing hose. A two-hose system can also be provided that returns exhaled breathing gas to the breathing apparatus through an expiratory hose, where the exhaled volume can optionally be measured, and allows it to escape through the breathing apparatus to ambient air (fresh air). In that case, a valve substantially prevents exhaled breathing gas from entering the inhalation hose. It can also be envisioned that the patient interface and breathing apparatus are connected via a one-hose system with, for example, a patient valve controlled by the breathing apparatus. The valve can be switched to allow exhaled air to escape from the hose system directly to ambient air, at least during exhalation.

[0054] In the specification and claims, the terms gas and gas mixture are used synonymously. In particular, gas can also refer to a gas mixture. In particular, the second gas can be a gas mixture. In this case, the second gas can be, for example, inhaled ambient air or compressed / pressurized air supplied from a gas cylinder or supply line. In some embodiments, the second gas can be a mixture of inhaled ambient air or compressed / pressurized air and a rebreathed or refluxed gas mixture. In this case, the refluxed gas mixture can have a different concentration of the first gas than the initially generated gas mixture. In some embodiments, the first gas is oxygen, and the second gas is ambient air and / or a refluxed gas mixture and / or a mixture thereof.

[0055] It is further noted that "estimated gas flow rate forecast value" should be understood to mean any kind of estimated gas flow rate forecast value, unless expressly stated otherwise. In particular, "estimated gas flow rate forecast value" can include scaled estimated gas flow rate forecast values ​​in addition to (unscaled) estimated gas flow rate forecast values. Also, "estimated total flow rate forecast value" should be understood to mean any kind of estimated total flow rate forecast value, unless expressly stated otherwise. In particular, "estimated total flow rate forecast value" can include scaled estimated total flow rate forecast values ​​in addition to (unscaled) estimated total flow rate forecast values.

[0056] In the present invention, the input amount of the feedforward component is Operation amount In conventional feedforward control of gas flow, at least one input quantity of the feedforward component is a planned gas flow calculated from a measured total flow. This planned gas flow calculated from the measured total flow is replaced with a predicted planned gas flow that is determined or calculated from the predicted total flow.

[0057] According to the method of the present invention, which can be implemented, for example, by the respiratory device of the present invention, the concentration of a first gas, e.g., oxygen, is controlled, inter alia, by feedforward control of the gas flow rate of the first gas. The purpose of the feedforward control is to predetermine the gas flow rate and appropriately control it for the next or current breath. In addition to the feedforward component, a corrective adjustment component similar to a feedback control is also contemplated. In this case, the corrective adjustment component is based on a comparison of the actually measured gas flow rate with an intended value, regardless of the source of the error, to correct for possible inaccuracies or deviations. If the feedforward component achieves a gas flow rate that exactly corresponds to the set target value, no corrective adjustment is made. The corrective adjustment can also compensate for, for example, systematic errors in the feedforward control. If the gas flow rate resulting from the feedforward control always differs, for example, by a certain percentage from a predetermined target value, this can be compensated for by the corrective adjustment.

[0058] The predicted gas flow schedule of the controlled gas is used as an input quantity for determining the feedforward component. To determine the predicted gas flow schedule, a total respiratory gas flow schedule is predicted in a first method step. The current ventilation status is incorporated into the prediction. In this case, on the one hand, the ventilation status can reflect the patient's respiratory settings / parameters, and on the other hand, patient-related factors such as the patient's physiology can also be incorporated. In addition to the current ventilation status, a patient flow model is also incorporated into the calculation of the total flow prediction. Input quantities and / or factors of the patient flow model are the current ventilation status and at least a portion of the predetermined (ventilatory) pressure. For incorporation into the patient flow model, the current ventilation status is transformed, for example by an RC substitution model.

[0059] In some embodiments, it is contemplated that inaccuracies caused by actuating the gas valve can also be compensated for by controlling or adjusting the gas flow rate to set the gas concentration of the first gas. To this end, a further method step determines a correction factor, for example, to be used in the total flow rate prediction. This correction factor can also be adapted, for example, to the patient's breathing phase, i.e., inspiration and expiration. To determine the correction factor, it is contemplated that the ratio between a preset volume and / or an expected volume and the actually measured volume is determined, optionally averaged over several breaths. Based on this ratio, a correction factor to be used in the total flow rate prediction is determined for each breathing phase.

[0060] It is contemplated that a predicted gas flow rate of the first gas to be controlled is determined based on the total flow rate prediction calculated with the correction factor. In some embodiments, it is also contemplated that a predicted flow rate of the controlled gas is first determined from the total flow rate prediction, and then this predicted flow rate value is scaled by the correction factor.

[0061] In some embodiments, it is contemplated that the method step optionally also takes into account the volume fraction rebreathed into the breathing device and / or pushed back by the patient's exhalation. The rebreathing volume fraction is incorporated when determining the predicted flow value of the controlled gas. This method step can be performed in parallel with, before, or after the method step of determining the correction factor. In some embodiments, it is contemplated that the method step of considering the rebreathing volume is performed after the method step of determining the correction factor.

[0062] In one embodiment, a method sequence is provided in which, in a first method step, a total flow rate prediction is performed. Then, in a second method step, a correction factor calculated on the total flow rate prediction is determined. In a third method step, an optional determination of a rebreathing volume is performed. Subsequently, a predicted gas flow rate of the controlled gas is determined, optionally taking the rebreathing volume into account. The predicted gas flow rate of the controlled gas is then used as an input quantity for feedforward control of the gas flow rate. Together with the corrective adjustment, a control signal for valve switching is generated, which in turn controls or generates an actual gas flow rate. In this case, the measured actual gas flow rate is the variable used for the corrective adjustment. [Brief explanation of the drawings]

[0063] [Figure 1] 1 is a schematic diagram of an exemplary embodiment showing a sequence of a method 100 for controlling a gas flow rate 146. FIG. [Figure 2] FIG. 1 shows a schematic diagram of an exemplary sequence of method steps 110 for total flow prediction. [Figure 3] 1 is a diagram illustrating a flow rate scaling method step 120 in an exemplary embodiment. [Figure 4] FIG. 1 illustrates an exemplary embodiment of a method step 130 for determining a scaled predicted gas flow rate budget 133. [Figure 5] 1 shows a schematic diagram of method steps 140 for controlling 145 a gas valve in an exemplary embodiment. [Figure 6] 1 is a schematic and highly simplified illustration of an exemplary embodiment of a respiratory apparatus 200. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0064] The present invention will now be described in detail by way of example with reference to FIGS.

[0065] 1, a sequence of a method 100 for controlling a gas flow rate 146 is shown in a schematic diagram of an exemplary embodiment, in which the method 100 includes a method step 110 of total flow rate prediction, a method step 120 of flow rate scaling, a method step 130 of determining a predicted gas flow rate schedule 133, optionally scaled to take into account rebreathing volume, and a method step 140 of controlling a gas valve. In this case, the method step 140 of controlling a gas valve includes determining a gas flow rate from a corrective adjustment component and a feedforward component for controlling the gas valve. Operation amount This also includes the decision to:

[0066] The method 100 for controlling gas flow 146 is based on feedforward control, where the input amount of the feedforward component is used to control the gas valve. Operation amountIn this case, the advantage of feedforward control is that the control goes beyond pure control, thereby achieving improved reaction times, for example, when the gas flow rate changes. In classical feedforward control of the gas flow 146, at least one input quantity of the feedforward component can be a gas flow rate forecast value 141 calculated from the measured gas flow rate. This gas flow rate forecast value 141 calculated from the measured total flow rate is replaced by a predicted gas flow rate forecast value calculated from a predicted total flow rate forecast value 116. In this case, the determination of the predicted total flow rate forecast value 116 is performed, for example, in method step 110 of total flow rate prediction. In method steps 120 and 130, the predicted gas flow rate forecast value is determined from the predicted total flow rate forecast value 116 and scaled to arrive at a scaled predicted gas flow rate forecast value 133. In this case, in some embodiments, the predicted total flow rate forecast value 116 is first scaled, and then in method step 130, the scaled predicted gas flow rate forecast value 133 is determined from the scaled predicted total flow rate forecast value 127. Alternatively or additionally, the predicted gas flow budget is determined directly from the predicted total flow budget 116 and then scaled accordingly in method step 130. If optional consideration of the rebreathing volume V_Rueck is intended, V_Rueck is already incorporated into the calculation of the predicted gas flow budget before scaling. Optionally, in method step 130 of determining the scaled predicted gas flow budget 133, the rebreathing volume V_Rueck is also incorporated in order to arrive at a correspondingly adapted gas flow budget 133. In method step 140, the predicted gas flow budget 133 is calculated as a function of the total flow budget 116 for controlling the gas valves. Operation amount is used as the input for the feedforward component of

[0067] The method step 110 for total flow prediction, in which a predicted total flow budget 116 is determined, is shown schematically in an exemplary embodiment in FIG.

[0068] 2 shows a schematic representation of an exemplary sequence of method steps 110 for total flow prediction. Among other things, inputs for the total flow prediction are a predetermined pressure 111 for the breath and a current ventilation status 112. The ventilation status 112 can then, on the one hand, reflect the patient's ventilation settings / parameters and, on the other hand, incorporate patient-related factors, such as the patient's physiology. Breathing settings / parameters can be, for example, pressure (IPAP, EPAP, PEEP, etc.), flow rate, volume, ventilation time, ventilation mode (CPAP, APAP, BiLevel, etc.), respiratory rate (respiratory frequency), etc. Patient-related factors, such as the patient's physiology, can be, for example, age, height, weight, sex, illness, etc.

[0069] One possibility for representing the current ventilation status 112 is modeling of the patient by an RC surrogate model (RC equivalent model) 113. In addition to the RC surrogate model, other and / or further patient models can be used that, for example, more accurately represent the patient. The parameterization of the patient flow model 114 is performed, among other things, by evaluating the parameters of several previous breaths. The RC surrogate model 113 estimates or determines the course of the patient parameters, for example, from pressure and flow. The patient flow model 114 determines, for example, the gas flow to be delivered to the patient together with at least a predetermined pressure 111. That is, for example, the exemplary RC surrogate model 113 first represents the patient as a starting point, and then the patient flow model 114 determines, among other things, the patient flow together with the set ventilation pressure 111. For example, in the interaction between the RC surrogate model 113 and the patient flow model 114, the parameters of the penultimate tidal breath are used to evaluate the last tidal breath.

[0070] From the calculation of the patient flow model 114 and the current ventilation status 112, a predicted total flow 116 is calculated by calculation 115. In this case, the parameters / factors of the current ventilation status 112 that can be included in the patient flow model and that can be directly included in the calculation 115 of the predicted total flow 116 may be the same or different. It is contemplated that some parameters of the current ventilation status 112 may be included in the patient flow model 114 and directly included in the calculation 115 of the predicted total flow 116. Some parameters of the current ventilation status 112 may further only be directly included in the patient flow model 114 or in the calculation 115.

[0071] In that case, the predicted total flow budget 116 reflects the total flow delivered to / from the patient, i.e., the gas flow 146 plus the flow of ambient air inhaled, for example.

[0072] The method step 120 for flow rate scaling is shown diagrammatically in an exemplary embodiment in Fig. 3. In a scaling step 126, the predicted total flow rate budget 116 is scaled. To do so, inspiration data 121 and expiration data 122 of the patient 212 are taken into account as further input quantities for the scaling 126. In calculation steps 123, 124, performed separately for inspiration and expiration, respectively, a scaling factor or function is determined, with which the predicted total flow rate budget 116 is scaled. A switch 125 then switches between inspiration and expiration scaling depending on the respiratory phase.

[0073] In that case, the inspiration data 121 or expiration data 122 is a calculation that considers, for example, at least one ratio between the intended inspiration or expiration volume and the actually applied inspiration or expiration volume. Optionally, this ratio is averaged over multiple breaths and possibly weighted. The weighting can be based, for example, on the recency of the breath, e.g., more recent breaths being weighted more highly than older breaths. In some embodiments, further data and influences can also be taken into account in determining the scaling factor or function.

[0074] 4, an exemplary embodiment of a method step 130 for determining a scaled predicted gas flow budget 133 is shown. In an exemplary embodiment, method step 130 also includes optional consideration of a rebreathing volume V_Rueck, which is incorporated into the calculation 132 of the scaled predicted gas flow budget 133, illustratively by determining 131 the average concentration mcO2% of a first gas (e.g., oxygen) in a second gas / gas mixture. The average concentration mcO2% of a first gas in a second gas can be simply calculated, for example, for oxygen, by the following formula:

[0075]

number

[0076] Here, cO2R is the oxygen concentration in the rebreathing volume V_R, and V_Ges is the total respiratory volume of the last breath. It should be noted that in this case, the second gas is, for example, a gas mixture that may contain a specific concentration of the first gas. Here, the gas mixture (second gas) can be, for example, a respiratory gas containing a specific concentration of oxygen (first gas). In this case, the average concentration mcO2% takes into account both the freshly inhaled ambient air and the rebreathed respiratory gas. The purpose of observing the rebreathing volume V_R is to determine the total concentration of the first gas in the second gas. In this case, the first gas (100%) and the concentration of the first gas in the second gas are at least approximately known. In this case, rebreathing, i.e., the backflow of the gas mixture formed from the first and second gases, changes the concentration of the first gas in the gas mixture with which the first gas is mixed. Instead of the measured oxygen concentration cO2Rück, a target concentration of the first gas (here oxygen) in the second gas (here respiratory gas) can also be used. The above 21% refers to the oxygen content of ambient air. Alternatively or additionally, the oxygen content of the inhaled ambient air can be measured and this measured value can be substituted for the above 21%. If the proposed method is intended to control the flow rate of a gas other than oxygen, the values ​​must be adapted accordingly. A complementary or alternative approach is to use a non-constant, high, and then decreasing concentration of the first gas as the target volume (target variable). For example, the concentration can be low in the rebreathing volume, and the first gas can be mixed according to the target concentration in the next breath.

[0077] The calculation 132 of the scaled predicted gas flow budget 133 incorporates the mean ambient air concentration mcO2% and the scaled predicted total flow budget 127, as well as, for example, the target concentration of at least the first gas in the respiratory gas.

[0078] The method steps 140 for the control 145 of the gas valve 203 are shown in an exemplary embodiment in Fig. 5. The exemplary embodiment of Fig. 5 shows the method steps 140 for the control 145 of the gas valve 203 from the correction adjustment component 143 and the feedforward component 144. Operation amount In that case, one of the input quantities of the feedforward component 144 is the scaled predicted gas flow rate budget 133, illustratively determined in method step 130.

[0079] For the correction adjustment component 143, the actual gas flow rate actual value 147 is compared with the predetermined gas flow rate target value 141. If the actual gas flow rate actual value 147 corresponds to the predetermined gas flow rate target value 141, the correction adjustment component 143 is zero, i.e., no deviation is identified. In that case, the correction adjustment component 143 is, for example, independent of the possible cause of the deviation and merely indicates whether and by how much the set gas flow rate target value 141 and the actual gas flow rate actual value 147 differ from each other. Additionally, in some embodiments, an error analysis can be performed, and the cause of the deviation can also be incorporated into the correction adjustment component 143. Alternatively or additionally, if there is a deviation between the actual gas flow rate actual value 147 and the set gas flow rate target value 141, a correction independent of the cause can be made by the correction adjustment component 143, and at the same time, an error analysis can also be performed to determine the impact of this on the feedforward component 144.

[0080] The feedforward component 144 is designed to incorporate possible valve control disturbances and / or inaccuracies in advance. In conventional feedforward control, the feedforward component 144 is determined based on a predetermined gas flow rate budget 141 determined from the measured total flow rate. In contrast, in the described method, the feedforward component 144 is based on a predicted gas flow rate budget, e.g., a scaled predicted gas flow rate budget 133. This can, for example, minimize reaction time and / or improve control quality. In this case, the feedforward component 144 is determined according to known prior art techniques. The feedforward component 144 can, for example, be determined by a model of the controlled valve or a valve characteristic curve, e.g., an inverse system model. In some embodiments, a mixture of formats and / or other models and / or characteristic curves can also be contemplated for determining the feedforward component 144.

[0081] An exemplary embodiment of the breathing apparatus 200 is shown diagrammatically and in a greatly simplified manner in Figure 6. In that case, the breathing apparatus 200 is set up and configured to control the gas valve 203 by means of feedforward control, in particular by means of the control unit 214 and the calculation unit 213.

[0082] The respiratory device 200 is configured and set to monitor and at least partially analyze the breathing of the patient 212. For example, the respiratory device 200 is configured to recognize respiratory phases (inhalation, exhalation). The respiratory device 200 can also be configured to recognize various respiratory conditions, such as apnea, snoring, apnea, irregular breathing, weak breathing, etc. It is contemplated that the respiratory device 200 is configured to at least partially automatically set determined ventilation parameters, such as pressure and / or flow rate and / or volume and / or rate, to assist and / or pre-set (prescribe) the breathing of the patient 212 at least phase by phase. The respiratory device 200 is configured and set to assist the breathing of the patient 212 at least phase by phase and / or to pre-set the breathing of the patient 212.

[0083] The respiratory apparatus 200 comprises at least two gas sources 201, 206. Each of the gas sources 201, 206 is configured to provide the respiratory apparatus 200 with at least one gas or gas mixture.

[0084] In the illustrated exemplary embodiment, the gas source 201 is an oxygen source. Illustratively, the oxygen source 201 comprises at least one connection for connecting a compressed gas, such as an oxygen cylinder. Alternatively or additionally, it may be provided that the oxygen source 201 comprises an oxygen concentrator integrated into or connected to the respiratory apparatus 200. If a compressed gas source, such as an oxygen cylinder, is connected to the oxygen source 201 of the respiratory apparatus 200, it may be provided that a pressure reducer is arranged between the compressed gas source and the respiratory apparatus 200. Alternatively or additionally, the pressure reducer from the oxygen source 201 may also be arranged in the respiratory apparatus 200. Additionally, it may be provided that the oxygen source 201 optionally comprises a filter.

[0085] Illustratively, a pressure sensor 202 configured to measure the pressure of the oxygen being delivered is pneumatically connected to the oxygen source 201. In some embodiments, the respiratory apparatus 200 is configured and arranged to infer the fill level of the oxygen source 201 or a compressed gas source connected thereto from the pressure measured by the pressure sensor 202. In some embodiments, a warning or alarm is issued via the user interface 218 when the fill level is low.

[0086] The pressure sensor 202 is followed by a controllable valve 203 which controls the oxygen flow rate (oxygen flow) 106 from the oxygen source 201 to the mixing region 205. The control of the valve 203 is performed, for example, by a control unit 214 according to the method of the present invention.

[0087] Following the valve 203 is a flow sensor 204 configured and arranged to measure the flow rate of the oxygen stream.

[0088] In the illustrated embodiment, the at least second gas source 206 is illustratively configured as an intake region 206 for ambient air. The intake region 206 is optionally equipped with a filter for filtering the ambient air. For example, the ambient air may be at least partially filtered to remove pathogens and other contaminants. In some embodiments, the intake region 206 may include a gas delivery unit configured to draw in the ambient air. In the exemplary embodiment shown in FIG. 5 , the ambient air is drawn through the intake region 206 by a fan 208. Alternatively or in addition to the intake region 206, the respiratory apparatus 200 may also have a connection to a compressed gas source, such as a compressed air cylinder. A flow sensor 207 is disposed on the gas source 206 or subsequent to the intake region 206, and is configured and arranged to measure the flow rate of the gas flow from the intake region 206 toward the mixing region 205.

[0089] The respiratory apparatus 200 comprises a mixing region 205 in which the gas flows from the gas source 201 and the gas flow from the gas source 206 flow together and at least partially mix. In some embodiments, the mixing region 205 is formed as a mixing chamber having a volume and optionally having a particular structure that improves the mixing of the two gases. Alternatively or additionally, it is also contemplated that active mixing is provided, for example by means of rotors and / or swirlers (agitators). In some embodiments, the mixing region 205 is realized by simply joining the two gas flow paths from the gas sources 201, 206 together. For example, a Y-piece can be provided for this purpose.

[0090] Following the mixing region 205 is a controllable fan 208 configured and set to pump the gas mixture from the mixing region 205, for example as breathing gas. It should be noted that in some circumstances, the valve 203 is closed and no gas flows from the gas source 201 to the mixing region 205, so that the gas mixture or breathing gas from the mixing region 205 consists solely of the gas / gas mixture, as the case may be, drawn from the gas source / intake region 206. In some embodiments, the fan 208 is also configured and set to draw ambient air through the intake region 206. The fan 208 is set to provide a configurable pressure and / or flow rate of the breathing gas to be pumped from the mixing region 205.

[0091] The oxygen content of the delivered breathing gas is measured by an oxygen sensor 209. The measured oxygen content may for example be incorporated into the control of the valve 203, in order to be able to correct deviations from a predetermined value. For example, the ambient air may have an oxygen concentration different from the assumed 21%, so that the correct oxygen flow rate 116 is set, but the oxygen concentration in the breathing gas does not correspond to the predetermined value.

[0092] Illustratively, oxygen sensor 209 is followed by a pressure sensor 210 configured to detect breathing gas pressure in the breathing gas line after fan 208. Illustratively, pressure sensor 210 is followed by a flow sensor 211 configured and arranged to detect or measure breathing gas flow.

[0093] The respiratory apparatus 200 is exemplarily connected to the patient 212 via a hose system 219 and a patient interface (not shown). For example, the hose system 219 may be a leak system, a two-hose system, or a one-hose valve system. In the case of a leak system, the hose system and / or the patient interface have an intentional leak that allows breathing gas exhaled by the patient 212 to at least partially escape. In that case, in some embodiments, a portion of the exhaled breathing gas is also directed toward the respiratory apparatus 200. In that case, it may be contemplated that the volume of the patient interface and the hose system is considered to be such that it can substantially prevent the exhaled breathing gas from entering the respiratory apparatus 200. In some embodiments of the respiratory apparatus 200, an additional valve, such as a check valve, is provided in the region of the connection of the hose system 219 to the respiratory apparatus 200, which substantially prevents rebreathing into the respiratory apparatus 200. In the case of a one-hose valve system, for example, it is contemplated that a valve near the patient is controlled by the respiratory apparatus 200 so that during patient exhalation, the exhaled gas can at least partially (temporarily) escape directly through the valve to the ambient environment.

[0094] The respiratory apparatus 200 has separate inspiratory and expiratory branches (not shown) for use with a two-hose system. Respiratory gas is delivered to the patient 212 via the inspiratory branch during patient 212 inspiration. During patient 212 expiration, exhaled respiratory gas is directed through the respiratory apparatus 200 via the expiratory branch and directed to the ambient environment. In some embodiments, the exhaled respiratory gas is filtered by a filter in the expiratory branch. When using a two-hose system, for example, a valve is disposed in the hose system 219 that closes the inspiratory branch during the expiratory phase, thereby preventing exhaled respiratory gas from entering the inspiratory branch. The exhaled respiratory gas is then returned through a second hose to the expiratory branch to the respiratory apparatus 200, through which it is directed, for example, to the ambient air. For example, a valve delay may cause a small portion of the respiratory gas to be pushed back into the inspiratory branch of the respiratory apparatus 200. However, in that case, exhaled breathing gas is substantially prevented from reaching the inspiratory limb of the breathing apparatus 200.

[0095] Illustratively, the respiratory apparatus 200 comprises at least one calculation unit 213 , a control unit 214 , a detection unit 215 , a monitoring unit 216 , a storage unit 217 and a user interface 218 .

[0096] The calculation unit 213 is configured to calculate a value for controlling the gas valve 203. Operation amount , and / or feedforward component 144 and / or corrective adjustment component 143 and / or feedforward component 144 are configured and configured to calculate input quantities, such as predicted gas flow rate budgets.

[0097] The calculation unit 213 is exemplarily configured to at least partially perform the method 100. In some embodiments, the calculation unit 213 is configured to perform the calculation steps of the method 100, and the control unit 214 is configured to control the gas valve 203 based thereon. The calculation unit 213 is configured to predict / predict a total flow budget 116 from the current ventilation situation 112 and the set ventilation pressure 111 (pressure setpoint) in a first method step 110. In a further method step 120, the calculation unit 213 calculates a scaled total flow budget 127 from the predicted total flow budget 116 and the inspiration and expiration data 12. In a further method step 130, the calculation unit determines a scaled predicted gas flow budget 133 from the scaled total flow budget 127 and optionally incorporating a rebreathing volume V_Rück.

[0098] In some embodiments, the calculation unit 213 may first calculate a predicted gas flow target value from the predicted total flow target value 116, optionally incorporating the rebreathing volume V_Rueck, in method step 130. This predicted gas flow target value is then used as an input value for determining a scaled gas flow target value 133 (instead of the scaled total flow target value 127) in method step 120, instead of the gas flow target value 116. That is, method steps 120 and 130 are interchangeable, and depending on the order, the scaled total flow target value 127 and then the scaled gas flow target value 133 are determined, or the predicted gas flow target value is first calculated from the predicted total flow target value 116 and then scaled to obtain the scaled gas flow target value 133.

[0099] The scaled predicted gas flow rate 133 is then used in method step 140 to calculate the predicted gas flow rate for control 145 of the gas valve 203. Operation amount is used as an input quantity for the feedforward component 144 of Operation amount can be determined, for example, by the control unit 214 and / or the calculation unit 213. In that case, the control unit 214 calculates the determined σ from the feedforward component 144 and the corrective adjustment component 143. Operation amount The gas valve 203 is controlled based on the

[0100] In some embodiments, in the calculation unit 213, the determination of the method steps 110, 120, 130 and the feedforward component 144 is represented by a single calculation, using the respective input quantities as variables. Operation amount 1 to 5 may be performed at least in part in a single calculation, with individual method steps representing, for example, individual parts of an equation.

[0101] The corrective adjustment component 143 is based on a comparison between a set target gas flow rate 141 and an actual measured gas flow rate 147. The actual gas flow rate 147 is measured by, for example, a flow sensor 204 and detected by a detection unit 215.

[0102] The control unit 214 is configured and arranged to control at least the valve 203. In some embodiments, the control unit 214 is also configured to control the fan 208. In addition, it may be contemplated that the control unit 214 is configured and arranged to control the entire respiratory apparatus 200. In some embodiments, it may alternatively or additionally be contemplated that there are separate control units for different functions and / or modules and / or components.

[0103] In some embodiments, it may be contemplated that the computing unit 213 is at least partially integrated into the control unit 214 and / or that the control unit 214 comprises the computing unit 213 .

[0104] The detection unit 215 is configured and arranged to detect and possibly process values ​​measured by the sensors. In some embodiments, the detection unit 215 is configured to receive and / or record signals generated by the sensors, for example in the form of voltage and / or current intensity and / or frequency. Alternatively or additionally, it can be provided that the detection unit 215 is also arranged to convert the sensor signals into values.

[0105] The monitoring unit 216 is configured and arranged to detect (technical) problems with the respiratory apparatus 200. Technical problems may be, for example, a low battery level, an electronics error, a battery failure, a component and / or module failure, a power outage, a malfunctioning accessory, an invalid measurement value, or a temperature outside of the acceptable range. The monitoring unit 216 may further be arranged to generate an alarm and / or a message if a technical problem is recognized. In some embodiments, it may be contemplated that the monitoring unit 216 is arranged to detect a low filling level and / or an insufficient supply of the working medium, e.g., gas. For example, it may be contemplated that the monitoring unit 216 is arranged to be able to recognize, based on the pressure of the gas source 201 of the first gas, whether the supply has decreased and / or is insufficient.

[0106] The (intermediate) results of the calculation unit 213 and the measured values ​​detected by the detection unit 215 are stored and / or intermediately (temporarily) stored in the storage unit 217. In this case, intermediate storage means that the data is automatically deleted or allowed to be overwritten after a certain period of time and / or after an action and / or event has (automatically) taken place.

[0107] Data and / or information can be input and output via the user interface 218, e.g., a unit including input and output elements. For example, the configuration of the respiratory apparatus 200 and settings for ventilation can be performed via the input elements. The output elements, e.g., a display, can be configured to display information and data related to the current ventilation and settings. Furthermore, alarms and warnings regarding the functioning of the apparatus and also the ventilation of the patient 212 can be output via the user interface 218. For example, preset values ​​for ventilation, e.g., pressure, flow rate, volume, duration, program, etc., can be input via the user interface 218. An (initial) target value for the oxygen concentration in the respiratory gas can also be specified. In some embodiments, the target value for the oxygen concentration in the respiratory gas is optionally automatically adapted by the respiratory apparatus 200 during ventilation (breathing). Additionally, in some embodiments, an initial oxygen concentration can be specified by the user, and the respiratory apparatus 200 can automatically readjust the oxygen concentration during use. In that case, it may be provided that, for example, an oxygen concentration is first defined and that the respiratory device 200 automatically sets said defined oxygen concentration only if, for example, the oxygen supply of the patient 212 cannot be maintained at a preset value and / or is oversupplied to an extent that is harmful to the patient 212. For this purpose, it may be provided, for example, that data on the oxygen saturation of the blood of the patient 212 is supplied to the respiratory device 200 by a pulse oximeter.

[0108] Thresholds and limits may also be entered via the user interface, such as minimum and maximum oxygen concentrations, minimum and maximum oxygen flow rates, minimum and maximum respiratory gas pressures, etc. The thresholds and limits may also be considered alarm limits.

[0109] In some embodiments, the user interface 218 alternatively or additionally comprises an interface for connecting external display and / or input devices, such as a monitor (display screen), a keyboard, and / or a remote control.

[0110] It is noted that in some embodiments, in addition to the illustrated components of the respiratory apparatus 200, further elements may be arranged in and / or connected to the respiratory apparatus 200. For example, an additional respiratory gas humidifier, optionally equipped with a respiratory gas heater, may be provided. For example, it is also contemplated that a nebulizer may be arranged in and / or connected to the respiratory apparatus 200. In addition, in some embodiments, an expiratory branch may be provided with corresponding valves and controls. Via such an expiratory branch, the respiratory gas exhaled by the patient 212 in the respiratory apparatus 200 is led to the ambient air. Furthermore, one or more bypass valves may optionally be arranged in the pneumatic device of the respiratory apparatus 200, for example, to allow the patient to breathe at least temporarily in the event of a shortage of energy supply.

[0111] If additional components are connected to and / or disposed in the respiratory apparatus 200, it may be contemplated that these will also be incorporated into the determination of the predicted gas flow budget by the calculation unit 213. For example, changes in gas flow due to the use of a nebulizer and / or a respiratory gas humidifier may be taken into account.

[0112] Additionally, it may be envisaged that the respiratory apparatus 200 has at least one interface for connecting to a remote station at a distance, for example for telemedicine.

[0113] In some embodiments, it is also contemplated that the respiratory apparatus 200 is configured as an anesthesia apparatus. For this purpose, at least one, preferably additional, gas source is provided, via which anesthesia gas is introduced into the respiratory gas. For this purpose, it is also contemplated that the control and control device of the present invention is used to control the flow rate of the anesthesia gas. For example, it is contemplated that the control and control device of the present invention is used in parallel to control the gas valve 203 of the first gas source 201 and, for example, to control further gas valves of the anesthesia gas source.

[0114] In some embodiments, it is also contemplated that the control unit 214 is used separately, i.e., independently of the breathing apparatus 200, to control the gas valve 203. For example, it is also contemplated that the control unit 214 is utilized to control the gas valve 203 in another context in which a mixing of at least two gases is contemplated. The same applies to the method. In this case, for example, the patient model 114 is replaced by a model of a consumer. In this case, inspiration can be considered, for example, by the supply of a gas mixture to the consumer, and expiration can correspond, for example, to the exhalation of a used (consumed) or transformed gas mixture. [Explanation of symbols]

[0115] 100 ways 110 First Method Step 111 Pressure (predetermined) 112 Ventilation status 113 RC replacement model 114 Patient Flow Model 115 Calculation of the predicted total flow rate 116 Total flow rate (forecast) 120 Second Method Step 121 Intake Data 122 Breath Data 123 Calculation Steps 124 Calculation Steps 125 Switch 126 Scaling 127 Total flow forecast (forecast, scaling) 130 Third Method Step 131 Determination (mcO2%) 132 Calculation of predicted gas flow rate 133 Gas flow rate forecast 134 Gas flow rate forecast (forecast, scaling) 140 method steps 141 Gas flow rate plan value (predetermined) 143 Correction adjustment component 144 Feedforward Component 145 Control 146 Gas Flow Rate 147 Actual gas flow rate 200 Breathing apparatus 201 Gas Source 202 Pressure Sensor 203 Gas Valve 204 Flow Sensor 205 Mixed area 206 Gas Source / Suction Area 207 Flow Sensor 208 Fans 209 Oxygen Sensor 210 Pressure Sensor 211 Flow sensor 212 patients 213 Computational Units 214 Control Unit 215 Detection Unit 216 Surveillance Unit 217 Memory Unit 218 User Interface 219 Hose System

Claims

1. 1. A control unit (214) for a breathing apparatus (200), the control unit (214) configured and arranged to perform a method (100) for controlling a gas flow rate (146) of at least one first gas for mixing with at least one second gas, the method (100) comprising at least one method step (140) of controlling (145) a gas valve (203), wherein at least one manipulated variable for controlling (145) the gas valve (203) is determined from at least one corrective adjusting component (143) and at least one feedforward component (144), an input variable of the feedforward component (144) being a predicted gas flow rate schedule value (133, 134) of the first gas.

2. 2. The control unit (214) of claim 1, wherein the method (100) further comprises a first method step (110) of total flow rate prediction, a second method step (120) of flow rate scaling, and a third method step (130) of determining predicted gas flow rate schedule values ​​(133) and / or scaled predicted gas flow rate schedule values ​​(134).

3. 3. The control unit (214) according to claim 2, characterized in that in the first method step (110), a predicted total flow rate schedule value (116) of the gas mixture of at least two gases is determined starting from a set pressure value (111) and a ventilation situation (112).

4. 3. The control unit (214) of claim 2, characterized in that the first method step (110) includes a patient flow model (114), the set pressure value (111) and the ventilation status (112) are at least partially included in the patient flow model (114), and the results of the patient flow model (114) and at least a portion of the ventilation status (112) are included in the calculation (115) of a predicted total flow schedule value (116).

5. 3. The control unit (214) according to claim 2, characterized in that in the first method step (110), an initial value of a patient flow model (114) is determined from the ventilation situation (112) by means of a patient model, in particular in the form of an RC substitution model (113).

6. 3. The control unit (214) of claim 2, characterized in that in the second method step (120), a scaled predicted total flow rate forecast value (127) and / or the scaled predicted gas flow rate forecast value (134) is calculated from the predicted total flow rate forecast value (116) alone or from the predicted total flow rate forecast value (116) combined with the predicted gas flow rate forecast value (133).

7. 3. The control unit (214) of claim 2, characterized in that in the second method step (120), a scaled predicted total flow rate forecast value (127) and / or the scaled predicted gas flow rate forecast value (134) are calculated from the predicted gas flow rate forecast value (133).

8. 3. The control unit (214) of claim 2, wherein the second method step (120) includes scaling (126), wherein separate scaling factors and / or scaling functions are determined for inspiration and expiration, and wherein a switch (125) switches between the scaling factors and / or scaling functions depending on inspiration or expiration.

9. 9. The control unit (214) according to claim 8, characterized in that for determining the scaling factor and / or the scaling function, at least one comparison between a planned inspiration volume or expiration volume and an actually applied inspiration volume or expiration volume is taken into account.

10. 3. The control unit (214) of claim 2, wherein the third method step (130) comprises calculating (132) a predicted gas flow rate budget (133) from a predicted total flow rate budget (116).

11. 3. The control unit (214) of claim 2, wherein the third method step (130) includes determining an average concentration mcO2% of the first gas in the second gas, and wherein the determination of the average concentration mcO2% of the first gas also incorporates a rebreathing volume V_Rück.

12. 3. The control unit (214) according to claim 2, characterized in that in the third method step (130), the determined average concentration mcO2% of the first gas is incorporated into the determination of a predicted gas flow rate schedule (133).

13. 2. The control unit (214) of claim 1, wherein the input quantity of the feedforward component (144) for determining the manipulated variable for controlling (145) the gas valve (203) is a scaled predicted gas flow rate schedule value (134), optionally taking into account a rebreathing volume V_Rück.

14. 2. The control unit (214) of claim 1, wherein the input quantity of the correction adjustment component (143) includes at least one parameter representative of the deviation of an actual gas flow rate value (147) determined by at least one flow rate sensor (204) from a predetermined target gas flow rate value (141).

15. 2. The control unit (214) according to claim 1, characterized in that the corrective adjustment component (143) of the manipulated variable for controlling (145) the gas valve (203) becomes zero when the gas flow value (147) corresponds to the scheduled gas flow value (141).

16. 2. The control unit (214) according to claim 1, characterized in that the first gas is oxygen and the second gas is ambient air or compressed / pressurized air or a gas mixture from ambient air and / or compressed / pressurized air and / or at least partially rebreathed breathing gas.

17. 2. The control unit (214) according to claim 1, characterized in that the control unit (214) is configured to calculate a rebreathing volume V_Rück on the basis of measurement data of at least one flow sensor (204, 207, 211).

18. a. in said first method step (110), a predicted total flow budget (116) is calculated from at least one ventilation state (112), a set pressure value (111), and at least in part by a patient flow model (114); b. in said second method step (120), a scaled predicted total flow estimate (127) is determined from said predicted total flow estimate (116) and the inspiration data (121) and expiration data (122) by scaling (126), said scaling (126) being adapted to each respiratory phase; c. in the third method step (130), a scaled predicted gas flow rate (134) is determined from the scaled predicted total flow rate (127) and the mean concentration of the first gas, mcO2%, determined using the rebreathing volume V_Rück; d. The control unit (214) of claim 2, wherein in a fourth method step (140), an input quantity of the feedforward component (144) is the scaled predicted gas flow rate budget (134).

19. A breathing apparatus (200) comprising at least one control unit (214) according to at least one of claims 1 to 18.

20. 1. A method (100) for controlling a gas flow rate (146) of at least one first gas for mixing with at least one second gas, the method (100) comprising at least one method step (140) of controlling (145) a gas valve (203), wherein at least one manipulated variable for controlling (145) the gas valve (203) is determined from at least one corrective adjusting component (143) and at least one feedforward component (144), an input variable of the feedforward component (144) being a predicted gas flow rate schedule value (133, 134) of the first gas.

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