Respiratory system

Abstract

The invention relates to a breathing system (1) for assisting a gas exchange on a patient (2) by means of mechanical breathing, comprising a breathing device (3) for mechanically breathing the patient (2), which breathing device has a regulating device (5) for applying a gas and a breathing circuit (7). Furthermore, the respiratory system (1) has a dead space reduction device (4), which has a pump and reservoir unit (16) and a connection hose (17) to a pneumatic coupling point (18) at the patient interface (9). In order to provide a simpler structure, the invention proposes that the breathing system (1) is designed in such a way that a signal change, which is measurable by the breathing device (3) and is attributable to the activity of the dead space reduction device (4), for example a signal change for flow or pressure, is detected and / or calculated by the breathing device (3) as such a signal change, and is taken into account by the regulating device (5). As a result, the breathing device (3) can assist the dead space reduction device (4) and in this case can omit a second pump and reservoir unit (16).

Description

Technical Field

[0001] The present invention relates to a respiratory system having the features of claim 1 for assisting gas exchange at a patient site with mechanical respiration. Background Technology

[0002] Respiratory devices for mechanical ventilation of patients are known. According to the prior art, such as that described in EN ISO 80601-2-12, these respiratory devices typically include a graphical user interface (e.g., a touchscreen), a gas mixing unit, measuring devices for gas pressure and gas flow, and regulating devices. The regulating devices are used to periodically apply a settable gas mixture in a settable pressure direction, flow direction, or volume direction, according to a settable standard for the switching and characteristics of substantially alternating expiratory and inspiratory phases. The regulating devices typically also have monitoring devices with at least partially settable alarm limits. Furthermore, the respiratory device includes a breathing hose system and a patient interface.

[0003] Document EP3651842B1 discloses a dead space reduction device for assisting pulmonary gas exchange at a patient's site and for coupling to a respiratory device, comprising a flexible tubing that can be introduced into the patient's trachea, a pump unit, a reservoir unit, and a controller, the controller being configured such that, via the flexible tubing and by means of the pump unit, suction during the expiratory phase (especially end-expiratory phase) and retraction of suctioned gas during the inspiratory phase (especially end-expiratory phase) or early expiratory phase; wherein the dead space reduction device further comprises additional flexible tubing, additional pump unit, and additional reservoir unit for suctioning and retraction of gas from the respiratory tubing system of the respiratory device.

[0004] Alternatively, a flexible tubing that can be introduced into the patient's trachea can be used, or close-to-patient coupling can be achieved via a Y-shaped fitting near the intubation tube or a patient interface for performing non-invasive breathing (e.g., using a mask or helmet).

[0005] The system described in document EP3651842B1 is designed and capable of autonomously identifying the measurement signals required for its function through its own sensors, and thus provides its active dead space reduction function without the need for electrical or data coupling with the breathing apparatus. The operation of the dead space reduction device is typically performed via its own user interface.

[0006] The second pump and reservoir unit described in the dead space reduction device is necessary to achieve aerodynamic balance with respect to the effects of the first pump and reservoir unit on gas flow, gas pressure, gas volume, and gas composition in the respiratory system, such that these effects are substantially "invisible" to the coupled respiratory device and do not cause undesirable effects on its measurement, display, and regulation functions. For example, aspiration of gas in the patient's tracheal region might otherwise be detected by the respiratory device as a pressure drop and misinterpreted as the patient's inspiratory effort. The second pump and reservoir unit compensates for the aspiration of the first pump and reservoir unit by pumping gas in closer proximity to the respiratory device.

[0007] However, due to the requirement for a second pump and storage unit, this implementation of the dead space reduction device is technically complex, large, and heavy. Summary of the Invention

[0008] Therefore, the present invention is based on the objective of providing a simpler and more compact respiratory system.

[0009] The respiratory system according to the invention for assisting gas exchange at a patient site by means of mechanical respiration has a breathing device for performing mechanical respiration on the patient and a dead space reduction device.

[0010] The breathing device has a regulating device for applying gas (especially with a flow or pressure generator) and a breathing circuit, wherein the breathing circuit has a breathing hose system, a patient interface, and a connection device between the breathing hose system and the patient interface.

[0011] The breathing tubing system specifically includes an inspiratory branch between the gas outlet of the breathing device and the Y-shaped element, and an expiratory branch between the Y-shaped element and the expiratory valve controlled by the breathing device. The inspiratory and expiratory branches do not necessarily need to be guided as separate tubing, but can be implemented coaxially or in pairs with a common connecting wall; in both heated and unheated forms. Particularly in unheated tubing systems, a water collector can be used to separate moisture condensed from the breathing gas. According to the invention, embodiments without an expiratory tubing (with a valve or leak opening near the patient) and variations for high-flow nasal administration are also possible.

[0012] The patient interface is in particular a mask, helmet, nasal cannula, endotracheal tube, or tracheostomy tube. The connecting device is in particular a tube extension and also includes other components such as angled elements or closed suction systems. However, the connecting device can also be simpler, for example, consisting of a connector in which the patient interface and a Y-shaped element mate relative to each other.

[0013] The dead space reduction device has a pump and reservoir unit and a connecting hose leading to a pneumatic coupling point in the breathing circuit, particularly located at the patient interface or connection point. "Located at the patient interface" means, for example, connected to a mask, or passing through a mask to a nasal cannula, or external to the patient at an endotracheal tube, or passing through an endotracheal tube or tracheostomy tube in the patient's internal airway region, as described in documents DE102017006655A1 and DE102022004180A1. The breathing system, particularly the dead space reduction device itself, has a controller that allows the pump unit to set the suction during the expiratory phase (especially end-expiratory) and the retraction of the suctioned gas during the inspiratory phase (especially end-expiratory) or early expiratory phase.

[0014] The invention is characterized in that the respiratory system is designed such that signal changes measurable by the respiratory device attributable to the activity of the dead space reduction device (especially signal changes of flow rate, pressure, CO2, or other gas component signals measured by the respiratory device) are identified and / or calculated by the respiratory device as such signal changes and taken into account by the regulating device. "Flow rate signal" here refers to a signal related to volumetric flow rate and / or mass flow rate. "Identifying as such signal changes" means attributing the signal changes to the activity of the dead space reduction device based on existing data within the respiratory system (especially within the respiratory device), for example, by comparing data for flow rate with a stored sequence of characteristic data and / or stored limits. Preferably, the respiratory device is aware of the combination with the dead space reduction device and (if possible) further aware of the activity of the dead space reduction device (e.g., data for the current piston movement), and therefore "anticipates" these (specific) changes. However, it is also conceivable that the respiratory device can identify the activity of the dead space reduction device even without data coupling. "Calculating" here means that the respiratory system is aware of the combination with the dead space reduction device and calculates itself which signal changes will be anticipated due to the activity of the dead space reduction device. Recognition and computation can be combined.

[0015] Unlike known combinations of respiratory devices and dead space reduction devices, this respiratory device "knows" it is combined with a dead space reduction device and takes into account the activity of the dead space reduction device. This eliminates the need for a second pump and reservoir unit. The respiratory device learns, through data exchange with the dead space reduction device, when and by what magnitude changes in pressure, gas flow, volume, and gas composition near the patient are caused by the activity of the pump and reservoir unit, and can subtract these changes from the corresponding measurement signals, particularly using mathematical methods (e.g., addition, subtraction, proportional calculations, and / or filtering). The actual pressure / gas flow and volume balance is no longer achieved through a second pump and reservoir unit, but rather through the correspondingly adapted pressure / flow / volume regulation and gas mixing of the respiratory device.

[0016] Especially when data exchange between the dead space reduction device and the breathing apparatus is performed in near real-time and at a sufficiently high frequency (e.g., analog or at least 100 measurements per second, ideally significantly faster than the single cycle time of measurement detection by the breathing apparatus itself), compensation for the activity of the dead space reduction device is preferably performed within the measurement preprocessing (converting the raw signal to a standardized digital value, filtering, offset compensation, etc.), and therefore before the measurements are provided for further processing in regulation and monitoring. Alternatively, compensation can be performed within the measurement preprocessing, or it is conceivable to compensate by appropriately adapting the regulator-expected value of the breathing apparatus, or any combination of the methods. For example, thus, when the suction process begins with the dead space reduction device, the internal expected value of the PEEP pressure regulator of the breathing apparatus can be temporarily increased so that compensation is initiated before the pressure drop caused by suction occurs, and thus the "pressure sag" is minimized.

[0017] This has particular advantages: the intervention of the breathing device firmware can be well encapsulated, and therefore its impact and risks on the whole system can be well assessed, because there is no need to adapt algorithms for different breathing modes and settings combinations.

[0018] If adaptation for individual breathing modes and / or settings combinations is still required in the breathing device, such adaptation can be additionally considered in the firmware and / or hardware.

[0019] The measurement and regulation functions of the respiratory device are largely unaffected because the device is aware of all activities of the dead space reduction device, particularly regarding the effects caused by volumetric displacement (especially pressure changes and volumetric displacement) and the associated time points, and can therefore calculate and compensate for the resulting effects. This means, for example, that the timing of CO2-containing gas suction near the patient via the dead space reduction device, along with the time-related volumetric displacement, is known in the respiratory device, and therefore will not be misinterpreted as patient inspiratory activity even in the absence of pneumatic balancing provided by the second pump and reservoir unit. Pressure balancing can be achieved simply through the flow or pressure generator of the respiratory device.

[0020] To compensate for delays caused by sensor response time, data transmission time, and pneumatic transmission time, data transmission can also include estimated values ​​based on the pump's operating characteristics expected to occur at defined time points, as a supplement to or alternative to actual measurements. Therefore, after the pump is started, volumetric displacement can be predetermined with high accuracy for each time point based on defined operating characteristics (especially determined by acceleration, velocity, deceleration, and total stroke).

[0021] If data communication is bidirectional, allowing the dead space reduction device to also frequently consider the measured and setpoint values ​​and adjustment parameters of the breathing device in its control, further advantages can be obtained: The pump unit's operating timing and characteristics can be continuously adapted, particularly based on the settings and adjustment parameters and measurements transmitted from the coupled breathing apparatus (e.g., gas flow, exhaled CO2 content, expiratory time constant, dead space volume, respiratory cycle phase, breathing pattern, etc.). Therefore, both inhalation and re-injection can be performed with greater precision in time and function than could be achieved by current dead space reduction devices based solely on existing measurements. Furthermore, automatic adaptation of piston stroke is possible when coupled with breathing equipment capable of continuous CO2 mapping analysis. Since the effectiveness of dead space reduction devices is inherently limited by the actual dead space volume of the specific application, adaptation / limitation of piston stroke can minimize pump unit noise and wear, reduce the time window required for piston movement, and thus improve efficiency. This is especially true because shorter piston strokes require less time, allowing synchronization with the breathing apparatus even at higher respiratory rates.

[0022] By automatically adapting the adjustment of the breathing device according to the present invention to the aerodynamic effects of the dead space reduction device, further advantageous options are provided for the timing control of the pump and reservoir unit: at the end of exhalation, it is now alternative to simply retract the aspirated gas or to inject fresh gas (continuous or pulsed), while aspiration can be performed during the inhalation phase, because, as mentioned above, the breathing device is able to identify and balance the resulting effects.

[0023] Preferably, the dead space reduction device has exactly one pump and reservoir unit, and the breathing device has exactly one flow or pressure generator for dispensing (or dose delivery, i.e., Dosierung) the gas to be applied. Thus, a second pump and reservoir unit is specifically eliminated, and the breathing device has no additional flow or pressure generator, only the one generally required in any breathing device. The flow or pressure generator particularly includes a motor and a fan.

[0024] This invention proposes that the dead space reduction device has a sensor, particularly a CO2 sensor or a pressure sensor, and that the signal from the sensor can be directed to and processed by the regulating device of the respiratory apparatus. This coupling is achieved by the regulating device taking into account not only the signals detected by the respiratory apparatus based on its own sensors, but also additional signals that provide important additional information, especially since the dead space reduction device can determine values ​​very close to the patient via sensors. In particular, the correct pneumatic coupling of the dead space reduction device in the respiratory circuit can be identified via the CO2 sensor.

[0025] Preferably, the dead space reduction device has a pressure measuring device coupled to the breathing device such that the measurement data of the pressure measuring device can be processed by the regulating device of the breathing device to detect and, in particular, compensate for flow losses in the dead space reduction device, the breathing tubing system, or the patient interface.

[0026] In particular, the expansion of the measurement and control algorithms for the respiratory device includes: automatic identification of the catheter (especially as part of a closed suction system) introduced into the patient's trachea and connected to the dead space reduction unit; and the possibility of programmable compensation for the resulting effects (especially pneumatic effects). This identification can be achieved, for example, in the respiratory device by comparing or verifying the pressure at the reservoir unit measured and transmitted by the dead space reduction device, and the pressure and gas flow in the area of ​​the Y-shaped element or patient connection opening. This also avoids affecting the intubation compensation for inspiratory and / or expiratory processes set by the user, or achieves fully automatic compensation for actual pneumatic resistance up to the tip of the intubation or tracheostomy tube.

[0027] The invention further proposes that the breathing device has an expiratory flow restriction, allowing the expiratory flow to be set via an operator interface, and particularly, the temporal direction of the flow can be input via ramp time and / or flow curves, wherein instantaneous volumetric flow rate or cumulative volumetric flow rate or instantaneous mass flow rate or cumulative mass flow rate or pressure is understood as flow. In particular, the flow restriction (e.g., via expiratory ramp time or expiratory pressure or the shape of the flow / volume curve) can be defined in the operator interface, and thereby coordinated with the optimal timing for the activity of the dead space reduction device.

[0028] Preferably, the main settings and operating elements of the dead space reduction device, as well as messages and alarms, are integral parts of the operator interface of the respiratory device. In particular, all settings and related signal transmissions (especially messages and alarms) of the dead space reduction device are integrated into the operator interface of the respiratory device. Therefore, the user obtains all relevant information in a unified display; the same applies to all settings related to breathing. This significantly improves ease of use and, for example, allows for the expansion of data technology interfaces between the respiratory device and hospital information systems, central monitoring equipment, etc., to include data from the dead space reduction device.

[0029] By omitting the second pump and reservoir unit, the device for dead space reduction can be implemented with a significantly smaller structural size and weight than existing technologies, allowing it to be arranged / installed immediately adjacent to (preferably below) the coupled breathing apparatus, for example, on a common equipment vehicle (as an equipment carrier) or other carrying system. In an alternative embodiment, the dead space reduction device is spatially integrated, i.e., at least the pump and reservoir unit are substantially arranged inside the breathing apparatus.

[0030] Therefore, in a preferred embodiment, the respiratory system has a device carrier, and the dead space reduction device is arranged below the respiratory device on the device carrier in the use position. This eliminates the space requirement for additional equipment at the patient's bedside. In particular, the dead space reduction device and the respiratory device are arranged so harmoniously that they also visually form a single functional unit.

[0031] In order to make the best use of the limited space for the breathing device and dead space reduction device in the equipment carrier, and at the same time achieve ergonomic operation, the dead space reduction device is preferably positioned such that the axis of motion of the pump and reservoir unit is parallel to the user-facing side of the imaginary cuboid surrounding the breathing device, and is arranged horizontally in the use position.

[0032] To ensure trouble-free operation of the dead space reduction device in terms of condensation in the functional components (e.g., wiring and storage units) that guide the patient's gas, temperature regulation may be necessary. Condensation can be reduced or prevented by raising their wall temperatures to at least the temperature corresponding to the dew point of the contained gas. Various heating techniques can be used, such as hot air permeation, electric heating, or a combination of these methods. Therefore, the present invention proposes that the storage unit and / or connecting hose of the dead space reduction device include or operate in conjunction with temperature regulation devices. Alternatively, it is also conceivable that the heat and / or moisture of the gas drawn through the dead space reduction device can be temporarily stored near the patient in heat exchangers and / or moisture exchangers.

[0033] To ensure the hygienic and functional operation of the dead space reduction device and to assist the user in this regard, it is preferable that potentially contaminated components of the dead space reduction unit be designed to be replaceable without tools. In particular, these replaceable components are provided either as pre-installed patient kits or as parts attached to disposable breathing tubing kits.

[0034] The fitting or removal of these patient-related components of the dead space reduction device is preferably performed from the operating side of the coupled respiratory device. For this purpose, the user only needs to activate unlocking or locking in the user interface, and then the kit consisting of the patient-related components of the dead space reduction device can be removed or inserted without tools. No other user activities are permitted, especially activities for coupling measurement elements.

[0035] By reducing the number of pneumatic coupling points in the breathing circuit of the dead space reduction device, further advantages in terms of simple and error-proof operation can be achieved. Instead of the previous three coupling points, only a coupling point close to the patient is now required; coupling points for the second pump and reservoir unit can be eliminated, as can the pressure measurement wiring leading to the connection at the breathing device. This not only significantly simplifies operation for the user but also allows for a significantly slimmer, lighter, and simpler implementation of the dead space reduction device's patient kit / hose system.

[0036] For inhaled sedation of patients undergoing respiration, at least one dosing unit for volatile anesthetic gases, such as an anesthetic gas reflector known as EP3471808A1, and a device for measuring the concentration of the anesthetic gas are typically required. Since the respiratory system according to the invention preferably already includes a unit for gas analysis of gases aspirated from the dead space, the invention proposes that the respiratory system have a dosing device for volatile anesthetic gases or other therapeutic gases (e.g., NO, CO2) or humidifier water for “active HME,” which can be set via an operator interface. In particular, the dosing device is fluidly coupled to a dead space reduction device. Alternatively or additionally, the dosing unit may be mechanically and / or digitally coupled to the respiratory apparatus. The dosing unit is particularly located near the respiratory apparatus, preferably below it, but may also be housed in a separate housing.

[0037] From the user's perspective, the integration of the dosing unit for volatile anesthetic or therapeutic gases is advantageous because it eliminates the need for a separate GUI when operating via the graphical user interface (GUI) of the breathing apparatus. Furthermore, a separate measurement circuit for gas analysis is not required. However, the main advantage lies in the technical aspect, as the data exchange between the dosing device and the breathing apparatus (and therefore indirectly with the dead space reduction device) according to the invention allows for automatic dosing based on breathing parameters and gas analysis measurements.

[0038] To quickly flush out anesthetic gases from the patient (e.g., at the end of surgery), maximizing alveolar ventilation and eliminating anesthetic gases stored in the reflector are important. In this sense of the invention, the dead space reduction device includes at least one switchable valve having a fluid connection to an anesthetic gas absorber or an anesthetic gas suction device.

[0039] Therefore, the present invention proposes that a dead space reduction device or breathing device has a gas analysis unit by means of which gases, especially CO2 and / or volatile anesthetic gases, can be measured, and the gas analysis unit is coupled in such a way that the measurement data of the gas analysis unit can be processed by the adjustment device and / or dosing device of the dead space reduction device and / or breathing device.

[0040] The invention further proposes that the dosage of volatile anesthetic gas, therapeutic gas, or humidifier water is designed such that the dosage is based on a set and / or measured respiratory volume per minute, as well as a measured gas concentration or measured humidity and, if possible, temperature in the respiratory gas. Therefore, a user-side setting, such as a desired minimum alveolar concentration (MAC), can be automatically adjusted in the dosing device and automatically remains substantially constant or at a desired level even when respiratory parameters, etc., change. The dosing device may, in particular, be connected to or contain a reservoir. This reservoir may, for example, be a raw container (e.g., a bottle). The dosing device may also include a pump and / or a valve.

[0041] Furthermore, this invention proposes that, in the GUI of a breathing device, the filling level of the connected anesthetic gas absorber be calculated based on the amount of volatile anesthetic gas accumulated over time, and that this level be monitored in a configurable manner.

[0042] To rapidly flush out the anesthetic gas, another option according to the invention is to provide a fluid connection within the dosing device to an anesthetic gas absorber or aspiration device via a switchable valve. This fluid connection can be opened at an appropriate stage of the respiratory cycle via an adjustment device, thereby accelerating flushing.

[0043] For heating and humidifying breathing gases, heat and moisture exchangers (HMEs) are, in particular, existing technology. However, in certain application scenarios (e.g., under high leakage conditions), passive implementations are insufficiently efficient and require external supply of water and energy. According to the invention, the corresponding dosing for the “active” HME / enhancer at this time can also be achieved through an optional dosing unit, which is part of the system described herein, combined with data transmission from and to the breathing apparatus. Such data transmission can also be achieved indirectly (e.g., via a dead space reduction device), where the dead space reduction device here primarily acts as a relay station. The availability of relevant data about the breathing apparatus (especially breathing volume per minute and leakage) in the dosing device, provided by a unified GUI, is also advantageous.

[0044] As another element to assist the user, the present invention proposes a design scheme for the dead space reduction device in such a way that its activity (especially activity concerning piston movement) is visually identifiable to the user. To this end, in one embodiment according to the invention, the dead space reduction device is arranged behind a (partially) transparent cover, and its visibility is improved by means of an illumination device (e.g., by means of light-emitting diodes), although the actual user interface for setting and monitoring the dead space reduction device is located on the screen of the breathing device.

[0045] The present invention further proposes equipping the described respiratory system with a universal electrical interface so that central components, such as the user interface and power supply, can also be used with other similar functional units. A typical example of this is a medical suction unit conforming to EN ISO 10079. According to the invention, this can also be operated via a shared user interface, and through data technology coupling with the respiratory device, the respiratory pressure and respiratory volume can be automatically and accordingly increased before or at the start of the suction process. Another example could be an ultrasonic nebulizer or a screen nebulizer, which may require automatic adjustment of respiratory settings and humidification of the respiratory gas upon activation. Attached Figure Description

[0046] The invention will now be described using two variant embodiments with control structures. (See attached figures.) Figure 1 A schematic diagram of the respiratory system according to the present invention is shown; Figure 2 An exemplary diagram showing the parameters of a breathing device without dead space reduction; Figure 3 An exemplary diagram showing the parameters of a breathing device with a dead space reduction device (1 piston only) and no data exchange is shown; Figure 4 A schematic diagram showing the control structure of the respiratory system according to the invention in the first variant; and Figure 5 A schematic diagram of the control structure of the respiratory system according to the invention in the second variant is shown. Detailed Implementation

[0047] exist Figure 1 The diagram shows a respiratory system 1 according to the invention for breathing a patient 2. The respiratory system 1 includes a breathing device 3 and a dead space reduction device 4.

[0048] The breathing device 3 has an adjustment device 5 for gas application, including a motor and a fan serving as a flow generator 6, and a breathing circuit 7. The breathing circuit 7 includes a breathing hose system 8, a patient interface 9 in the form of an endotracheal tube, and a connecting device 10 in the form of a tube extension therebetween. The breathing hose system 8 includes an inspiratory bronchus 11, a Y-shaped member 12, and an expiratory bronchus 13. A breathing gas humidifier 14 is fluidly connected between the inspiratory bronchus 11 and the adjustment device 5. Furthermore, the breathing device 3 has a graphical user interface 15 in the form of a graphical user interface (GUI).

[0049] The dead space reduction device 4 includes a pump and reservoir unit 16 and a connecting hose 17 leading to a pneumatic coupling section 18 at the patient interface 9. Through the connecting hose 17, gas can be drawn from the breathing hose system 8 and the patient interface 9 at the coupling section 18 and then returned. This corresponds to document DE102017006655A1. Figure 2 The system shown illustrates the function of the first branch. The pump and reservoir unit 16 and the connecting hose 17, along with other components, can be replaced without tools if necessary. This allows for easy replacement, particularly of the components of the dead space reduction device 4, which may become contaminated with use. For patient treatment, these components (i.e., the pump and reservoir unit 16 and the connecting hose 17) are provided in a pre-assembled patient kit in a package (not shown) and are inserted into the dead space reduction device 4 without tools. A sensor 27 (here, a pressure sensor) is connected to the connecting hose 17, which serves as a pressure measuring device 28, and a gas analysis unit 29 in the form of a measuring cell is also connected. The sensor 27 and the gas analysis unit 29 are part of the dead space reduction device 4 and are connected by a cable (not shown).

[0050] Furthermore, the respiratory system 1 also has a first dispensing device 19 for inhaling sedation to the patient 2. An anesthetic gas reflector 20 is coupled to the first dispensing device 19, and the dispensing device 19 itself is fluidly coupled to a dead space reduction device 4 (not shown). This allows anesthetic gas to be supplied to the patient via the dead space reduction device 4.

[0051] Also fluidly coupled to the dead space reduction device 4 is the second dispensing device 21 for the active HME 22, i.e., the active heat and humidity exchanger. The active HME 22 is connected to the dispensing device 21 on one hand via the HME connecting hose 23 and on the other hand via the HME current line 24.

[0052] The dispensing devices 19 and 21, as well as the dead space reduction device 4, the breathing device 3, and the breathing gas humidifier 14, are interconnected via an electronic interface 25 and can communicate with each other. Furthermore, they are all mounted on or on a vehicle-type equipment carrier 26. The dead space reduction device 4 is directly positioned below the breathing device 3. The axis of motion A of the pump and reservoir unit 16 is horizontal and parallel to the user-facing side of an imaginary cuboid surrounding the breathing device 3. The two dispensing devices 19 and 21 are positioned below the dead space reduction device 4, more precisely, such that the dispensing devices 19 and 21, the dead space reduction device 4, the breathing device 3, and the breathing gas humidifier 14 terminate on a common plane facing the operator (not shown).

[0053] Not shown is the pump and reservoir unit 16 used not only for the dead space reduction device 4 but also for the temperature regulation device used for the breathing hose system 8.

[0054] To explain the function of respiratory system 1, firstly... Figure 2 The parameters of the breathing device 3 with the dead space reduction device 4 are shown. The flow rate (towards / from the patient) and the resulting respiratory volume V (in ml) are shown, as measured by the sensors of the breathing device 3. In the case of positive flow (flow to the patient), the volume increases; in the case of negative flow (flow from the patient), the volume decreases.

[0055] If this breathing device 3 is combined with, for example Figure 1 The dead space reduction device 4 shown is combined, but without data exchange, the result is... Figure 3 The image shown illustrates the variation not only in the flow rate signal (detail I) but also in the resulting volume (detail II). In particular, a volume V that rises shortly before the patient's actual inspiration may be misinterpreted by the breathing device 3 as an attempt at spontaneous breathing by the patient 2, resulting in erroneous respiratory control. In reality, this prematurely appearing positive flow / volume value is based on gas being drawn in at the coupling point 18 by the pump and reservoir unit 16 during this time period. To avoid this effect, document DE102017006655A1 proposes a second branch with a second pump and reservoir unit in the dead space reduction device 4, which balances the activity of the first branch, thereby keeping the dead space reduction device 4 "invisible" to the breathing device 3.

[0056] In contrast, the present invention proposes that the respiratory system 1 is capable of recognizing and / or calculating and taking into account signal changes attributable to the activity of the dead space reduction device 4 as such signal changes.

[0057] Figure 4 and Figure 5 A schematic diagram is shown. Figure 1 Two variations of the control structure of the respiratory system 1 in the text.

[0058] exist Figure 4 The regulating device 5 of the breathing apparatus 3 is shown on the right. As a central element, this regulating device has a processor P integrated with a power / battery management PM. The processor P communicates with the dead space reduction device 4 and with the operator interface 15 to receive operator input and present system status. Therefore, all settings and operating elements of the dead space reduction device 4, as well as messages and alarms, are integral to the operator interface 15 of the breathing apparatus 3. Measurement parameters, such as voltage, current, temperature, pressure, flow rate, or oxygen content, are detected by sensors (not shown) and transmitted as signals S in the form of raw measurement data. A unit SA for signal preprocessing is responsible for performing interference suppression, filtering, normalization, and / or integration on the raw measurement data, if possible, to form preprocessed measurement data, which is transmitted to the processor P. The processor P controls different actuators ACT, such as the flow generator 6, valves, or ventilation devices, based on user presets and measurement data. To this end, the processor P sends desired values ​​and receives actual values ​​or status feedback from the actuators ACT. The monitoring system FS continuously monitors the signal preprocessing unit SA, the processor P, and the actuator ACT, and checks for any critical conditions that could affect the safety of the breathing device 3, so as to intervene if necessary.

[0059] exist Figure 4 The dead space reduction device 4 is shown on the left, which has a very similar structure but lacks its own operator interface 15. The combination of processor P and power / battery management PM serves as the central element. For example, signals S from pressure measuring device 28 or gas analysis unit 29 are preprocessed by signal preprocessing unit SA. Processor P processes this data and controls actuators ACT, such as pump and storage unit 16 or temperature control unit. The two dispensing devices 19 and 21 can also be actuators ACT for dead space reduction device 4. However, they could also be actuators ACT for breathing device 3.

[0060] An electronic interface 25 for data exchange exists between the dead space reduction device 4 and the breathing device 3. Therefore, the operator interface 15 can also be directly or indirectly controlled by the dead space reduction device 4 to display operating status, allow operator input, etc. In particular, the first dosing device 19 for inhalation sedation can also be set via the operator interface 15. The processor P of the dead space reduction device 4 reports the activity of the dead space reduction device 4 to the processor P of the breathing device 3, including preprocessed measurement data from the signal preprocessing device SA. The processor of the breathing device 3 is designed such that it identifies predictable changes in the signal S based on this information and takes them into account when controlling the actuator ACT of the breathing device 3. For example, the suction process of the pump and reservoir unit 16 can be compensated by a correspondingly increased delivery from the flow generator 6. Furthermore, the processor P of the breathing device 3 can also receive measurement data from the gas analysis unit 29, particularly measurement data on the concentration of CO2 and / or volatile anesthetic gases, from the processor P of the dead space reduction device 4, process the data and generate data therefrom, and send it back to the processor P of the dead space reduction device 4, which thereby controls the first dispensing device 19 and / or the second dispensing device 21. Specifically, the first dispensing device 19 dispenses volatile anesthetic gases and / or therapeutic gases, and / or the second dispensing device 21 dispenses humidifier water, such that the dispensing is based on a set and / or measured breathing volume per minute and a measured gas concentration or a measured relative humidity in the breathing gas.

[0061] Interface 25 may also exist between the processor P of the dead space reduction device 4 and the signal preprocessing unit SA of the breathing device 3. Thus, during signal S preprocessing, the effects caused by the dead space reduction device 4 can already be considered, and the adapted measurement data can be further transmitted to the processor P of the breathing device 3. This can be done to such an extent that the processor P of the breathing device 3 remains largely unchanged compared to the processors of prior art breathing devices 3.

[0062] This coupling involves not only the conventional breathing state with dead space compensation, but also special states. For example, the signal from the pressure measuring device 28 can be used to identify flow losses, leaks, etc., and compensate for them on the breathing device 3 side.

[0063] exist Figure 5 In the variant of the control structure of the respiratory system 1 shown, many components are the same; therefore, to avoid repetition, only the differences will be described below. Figure 4Unlike other variations, the dead space reduction device 4 does not have its own signal preprocessing unit SA. Instead, all signals S (including those from the dead space reduction device 4) are processed by the signal preprocessing unit SA of the breathing device 3. The preprocessed measurement data then goes to the processor P of not only the dead space reduction device 4 but also the breathing device 3. This further simplifies the structure.

[0064] Other conceivable variations of the control structure include Figure 4 The structure, but with its own operator interface (not shown), or Figure 5 The structure is similar, but with only one processor P (not shown). For example, only the power / battery management PM is provided on the dead space reduction device 4 side, while the processor P of the breathing device 3 processes all pre-processed measurement data and also controls the actuator ACT of the dead space reduction device 4. In another variation, the power / battery management PM itself can be omitted on the dead space reduction device 4 side and is handled by the breathing device 3.

[0065] List of reference numerals 1. Respiratory system 2 patients 3. Breathing apparatus 4 Dead Space Reduction Device 5 Adjustment device 6-stream generator 7 Breathing Circuit 8. Breathing hose system 9 Patient Interface 10 connecting devices 11 Inspiratory branch 12Y-shaped parts 13 expiratory bronchus 14 Breathing Gas Humidifier 15. Operator Interface 16 pumps and storage unit 17 Connecting hose 18 coupling sites 19 First dosing device for inhalation sedation 20 anesthetic gas reflectors 21 Second dosing device for active HME 22 Active HME 23HME connecting hose 24HME current circuit 25 Electronic interfaces for data exchange 26 Equipment Carrier 27 sensors 28 Pressure measuring device 29 Gas Analysis Unit The motion axis of pump and storage unit 16 ACT actuator P / PM processor and power / battery management FS monitoring (functional safety) S signal SA is a unit used for signal preprocessing.

Claims

1. A respiratory system (1) for assisting gas exchange at a patient (2) by means of mechanical respiration, the respiratory system having an operator interface (15) and a respiratory device (3) for performing mechanical respiration on the patient (2), the respiratory device having an adjustment device (5) for applying gas and a breathing circuit (7), wherein, The breathing circuit includes a breathing hose system (8), a patient interface (9), and a connection device (10) between the breathing hose system (8) and the patient interface (9). The respiratory system has a dead space reduction device (4), which has a pump and reservoir unit (16) and a connecting hose (17) leading to a pneumatic coupling point (18) in the breathing circuit (7), the pneumatic coupling point being particularly at the patient interface (9) or at the connecting device (10). The respiratory system (1) is characterized in that signal changes attributable to the activity of the dead space reduction device (4) that are measurable by the respiratory device (3), particularly signal changes of flow rate, pressure, CO2 or other gas composition signals measured by the respiratory device, are identified and / or calculated by the respiratory device (3) as such signal changes and are taken into account by the regulating device (5).

2. The respiratory system (1) according to claim 1, characterized in that, The dead space reduction device (4) has exactly one pump and reservoir unit (16), and the breathing device (3) has exactly one flow or pressure generator (6) for dispensing the gas to be applied.

3. The respiratory system (1) according to claim 1 or 2, characterized in that, The dead space reduction device (4) has a sensor (27), particularly a CO2 sensor or a pressure sensor, and the signal of the sensor (27) can be directed to the regulating device (5) and processed by the regulating device.

4. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The dead space reduction device (4) has a pressure measuring device (28) that is coupled to the breathing device (3) such that the measurement data of the pressure measuring device (28) can be processed by the regulating device (5) of the breathing device (3) to detect and, in particular, compensate for flow loss in the dead space reduction device (4), the breathing hose system (8), or the patient interface (9).

5. The respiratory system (1) according to claim 1, characterized in that, The breathing device (3) has an expiratory flow restriction, which allows the expiratory flow to be set via the operator interface (15), and in particular, the flow time direction can be input via ramp time and / or flow curve, wherein instantaneous volumetric flow rate or cumulative volumetric flow rate or instantaneous mass flow rate or cumulative mass flow rate or pressure is understood as flow.

6. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The main settings and operating elements of the dead space reduction device (4), as well as messages and alarms, are part of the operator interface (15) of the breathing device (3).

7. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The respiratory system (1) has a device carrier (26) at which the dead space reduction device (4) is arranged below the respiratory device (3) in the use position.

8. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The axis of motion (A) of the pump and reservoir unit (16) is substantially parallel to the user-facing side of the imaginary cuboid surrounding the breathing device (3) and is arranged horizontally in particular in the use position.

9. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The pump and reservoir unit (16) of the dead space reduction device (4) and / or the breathing hose system (8) include or operate in conjunction with a temperature regulating device.

10. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The dead space reduction device (4) can replace potentially contaminated components that may be damaged by use without tools.

11. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The respiratory system (1) has a dosing device (19) for volatile anesthetic gases or other therapeutic gases, which can be set via the operator interface (15).

12. The respiratory system (1) according to claim 11, characterized in that, The dispensing device (19) is fluidly coupled to the dead space reduction device (4).

13. The respiratory system (1) according to any one or more of the preceding claims, characterized in that, The dead space reduction device (4) or the breathing device (3) has a gas analysis unit (29) by means of which gases, especially CO2 and / or volatile anesthetic gases, can be measured, and the gas analysis unit (29) is coupled in particular such that the measurement data of the gas analysis unit (29) can be processed by the adjustment device (5) of the dead space reduction device (4) and / or the breathing device (3) and / or the dosing device (19) according to claim 11 or 12.

14. The respiratory system (1) according to claim 1 and any one or more of claims 11 to 13, characterized in that, The dosage of the volatile anesthetic gas, therapeutic gas, or humidifier water is designed such that the dosage is based on the set and / or measured breathing volume per minute and the measured gas concentration or the measured relative humidity in the breathing gas.

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