Method for operating breathing air humidifier

Abstract

A breathing air humidifier (1) comprises a breathing air inlet (3), a breathing air outlet (5) and an electric heating element (9). The breathing air humidifier can be switched between a humidification mode and a preparation mode, the preparation mode is used for preparing operation of the breathing air humidifier in the humidification mode, the breathing air humidifier is designed to humidify breathing air input at the breathing air inlet in the humidification mode, the breathing air is conditioned by means of the heating element, and the heating element is designed to heat the breathing air input at the breathing air inlet in the preparation mode. The breathing air is provided at the breathing air outlet (5) in such a humidified state. A method for operating a breathing air humidifier includes switching the breathing air humidifier to a ready mode when the breathing air humidifier is turned on or off, and the breathing air humidifier is operated in the preparation mode, so that redundant heat generated by opening or closing the breathing air humidifier after the breathing air humidifier is operated in the humidification mode is dissipated from the inside of the breathing air humidifier, and the heating element is in a deactivated state.

Description

Technical Field

[0001] This invention relates to a method for operating a breathing air humidifier. Furthermore, the invention also relates to a control unit, a computer program, and a computer-readable medium for implementing the method, as well as a breathing air humidifier. Background Technology

[0002] Patients undergoing artificial respiration sometimes suffer from excessively dry airways. In such cases, a breathing air humidifier can be used to additionally humidify the inhaled air, which is then heated to a suitable temperature using an electric heating element. This can prevent or at least alleviate mucosal dryness. If artificial respiration is briefly interrupted, the breathing air inside the humidifier will continue to be passively humidified and / or heated because the heating element remains warm even after it has been turned off. This can cause the inhaled air to feel unusually warm and / or humid during the first few breaths after artificial respiration resumes. Summary of the Invention

[0003] The object of this invention is to provide a method for operating a breathing air humidifier, by which the inhaled breathing air is prevented from feeling abnormally warm and / or humid when restarting the humidifier after a brief interruption of operation. Another object of this invention is to provide a control unit, a computer program, and a computer-readable medium for implementing this method, as well as a corresponding breathing air humidifier.

[0004] These tasks are addressed by the subject matter of the independent claims. Advantageous embodiments of the invention are set forth in the dependent claims, the following description, and the accompanying drawings.

[0005] A first aspect of the invention relates to a method for operating a breathing air humidifier, particularly suitable for artificial respiration devices. The breathing air humidifier includes a breathing air inlet, a breathing air outlet, and an electric heating element. The breathing air humidifier is switchable between a humidification mode and a preparation mode, the preparation mode being used to prepare the breathing air humidifier for operation in the humidification mode. The breathing air humidifier is configured to humidify breathing air input at the breathing air inlet in the humidification mode, wherein the breathing air is temperature-controlled by the heating element (i.e., controlled to reach a temperature comfortable for inhalation) and provided in a humidified state at the breathing air outlet. The method includes: switching the breathing air humidifier to the preparation mode when the breathing air humidifier is turned on or off, and operating the breathing air humidifier in the preparation mode to achieve (or accelerate) the dissipation of excess heat generated from the opening or closing of the breathing air humidifier after operation in the humidification mode. When the breathing air humidifier is operated in the preparation mode, the heating element is deactivated.

[0006] In other words, whenever the breathing air humidifier is turned on or off, or more precisely, whenever it is detected that the breathing air humidifier is turned on or off (or should be turned on or off), the breathing air humidifier automatically runs in standby mode for a predetermined period of time to ensure sufficient passive and / or active cooling of the heating element and / or the air inside the breathing air humidifier before reactivating the humidification mode, such as before resuming a brief (e.g., less than 10 minutes, less than 5 minutes, or less than 3 minutes) interruption of artificial respiration therapy. Alternatively, switching to standby mode can be based on temperature. In this case, the breathing air humidifier is able to switch to standby mode only when it is turned on or off (see below) when a specific temperature is reached inside the breathing air humidifier.

[0007] The dissipation of excess heat can be passive and / or active, for example, by controlling one or more electro-pneumatic actuators accordingly.

[0008] The breathing air humidifier can operate in standby mode for a fixed, pre-defined running time (e.g., between 10 seconds and 5 minutes). Alternatively, the running time can be pre-determined based on the current (measured and / or estimated) temperature inside the breathing air humidifier.

[0009] The operation of the breathing air humidifier in standby mode can also be limited to preventing the breathing air humidifier from switching to humidification mode and / or preventing the activation of the heating element.

[0010] Unlike the preparation mode, the humidification mode is likely the primary operating mode of a breathing air humidifier. The operation of a breathing air humidifier in preparation mode can differ from that in humidification mode. In principle, operating a breathing air humidifier in preparation mode significantly reduces the likelihood that the breathing air supplied at the outlet will feel abnormally warm and / or humid when inhaled for a short period after the humidifier is turned on, compared to the corresponding operation in humidification mode.

[0011] It is feasible that the heating element is activated whenever the breathing air humidifier is turned on and / or whenever the breathing air humidifier switches to humidification mode; and / or whenever the breathing air humidifier is turned off and / or whenever the breathing air humidifier switches to standby mode. In other words, the heating element can be activated during the (entire) operation of the breathing air humidifier in humidification mode, and / or deactivated during the (entire) operation of the breathing air humidifier in standby mode. The heating element can be continuously turned on in the activated state. Here, the heating power of the heating element can be varied in an appropriate manner to adjust the temperature of the breathing air, for example by adjusting the current passing through the heating element and / or the voltage on the heating element (e.g., by pulse width modulation). Additionally or alternatively, the (average) heating power of the heating element in the activated state can be controlled by repeatedly alternating the turning the heating element on and off. Conversely, the heating element can be continuously turned off in the deactivated state, i.e., electrically decoupled from the electrical supply, so that the breathing air is not (or at least not targeted or actively) heated by means of the heating element.

[0012] When a breathing air humidifier is running in humidification mode, it can only switch back to standby mode after the humidifier has been previously turned off. In other words, once a breathing air humidifier is running in standby mode, it can only switch back to standby mode after the humidifier is turned on or off again. For example, the operation of a breathing air humidifier in humidification mode can only be interrupted by turning it off, not by switching to standby mode.

[0013] The breathing air humidifier can switch to power-off mode when turned off. In other words, the breathing air humidifier can be electrically decoupled from its power supply (such as a power supply via the grid and / or battery) when turned off. Alternatively, the breathing air humidifier can switch to energy-saving operation when turned off. The (off) breathing air humidifier can continue to be powered (such as via an additional battery) in energy-saving operation, however, it requires significantly less energy than in the on state. In particular, the heating element can be deactivated in energy-saving operation. Correspondingly, it is feasible, for example, that when the breathing air humidifier switches to humidification mode (rather than standby mode) when turned on, the energy-saving operation ends again when the breathing air humidifier is turned on. Alternatively, when the breathing air humidifier switches to standby mode when turned on, the energy-saving operation can be maintained when turned on. In other words, the (on) breathing air humidifier requires significantly less energy in standby mode than in humidification mode.

[0014] "Breathing air" can be understood as a single breathing gas or a mixture of multiple breathing gases used to provide artificial respiration to a patient. "Breathing gas" can be understood, for example, as carbon dioxide, oxygen, nitrogen, water vapor, or anesthetic gases.

[0015] Humidification of breathing air can be understood as the targeted mixing of breathing air with water vapor and / or water droplets, combined with targeted heating of the breathing air.

[0016] This method can be implemented by a computer, for example.

[0017] A second aspect of the invention relates to a control unit configured to implement the methods described above and below.

[0018] The control unit may include devices for data processing. These devices may be implemented as hardware and / or software and / or include a processor. The processor may be configured to implement (computer-implemented) methods. In addition to a processor, the control unit may also include at least one of the following devices for data processing: memory, a bus system for data communication between the memory and the processor, and a data communication interface for wireless and / or wired data communication with peripheral devices. Alternatively, the control unit may be implemented solely as hardware, for example, as an ASIC or FPGA component.

[0019] It should be noted that the features of the methods described above and below can also be features of the control unit (and vice versa).

[0020] A third aspect of the invention relates to a breathing air humidifier, particularly suitable for artificial respiration devices. The breathing air humidifier includes a breathing air inlet, a breathing air outlet, an electric heating element, and a control unit as described above and below. The breathing air humidifier can switch between a humidification mode and a preparation mode, the preparation mode being used to prepare the breathing air humidifier for operation in the humidification mode, the breathing air humidifier being configured to humidify the breathing air input at the breathing air inlet in the humidification mode, wherein the breathing air is temperature-controlled by means of the heating element and output in a humidified state at the breathing air outlet.

[0021] The breathing air inlet may be connected, for example, to a ventilator for invasive and / or non-invasive artificial respiration of a patient, to humidify the breathing air supplied by the ventilator before the patient inhales the air. "Ventilator" can also be understood as anesthesia equipment or a cough assist device (also known as an inspiratory-expiratory device) used to assist a patient's cough.

[0022] The breathing air outlet can be connected to the patient's respiratory system, for example, via one or more artificial respiration hoses and / or patient interfaces (such as masks, nasal cannulas, and / or catheters), thereby enabling artificial respiration of the patient with humidified breathing air.

[0023] Breathing air humidifiers can be configured to humidify breathing air by mixing breathing air with water vapor and / or water droplets on the one hand, and by adjusting the temperature through direct and / or indirect contact with a heating element on the other hand. For example, breathing air humidifiers can be configured to heat water by means of a heating element to generate water vapor to humidify breathing air, and / or to atomize water by means of a sprayer (such as a piezoelectric ultrasonic sprayer) to generate water droplets (especially aerosols) to humidify breathing air.

[0024] The control unit may, for example, be configured to control the heating element and / or one or more electro-pneumatic actuators when the breathing air humidifier is operating in humidification mode, so that the actual temperature of the breathing air supplied at the breathing air outlet is close to a desired comfort temperature at which inhaling the breathing air feels warm and comfortable. The comfort temperature may, for example, be between 30°C and 38°C.

[0025] The control unit can be configured in a corresponding manner to control the heating element and / or one or more electro-pneumatic actuators when the breathing air humidifier is in humidification mode, so that the actual relative humidity of the breathing air supplied at the breathing air outlet (relative to the corresponding ambient temperature) is close to the desired relative humidity, at which the inhaled breathing air feels moist and comfortable.

[0026] "Electrical heating element" can generally be understood as an electrically controllable heating element, especially a heating resistor. Heating elements may include, for example, heating rods, heating coils, and / or heating plates. Heating elements may be configured to directly and / or indirectly regulate the temperature of breathing air, for example, by heating a liquid that the breathing air comes into contact with as it flows through a breathing air humidifier.

[0027] Breathing air humidifiers can be implemented as stand-alone devices and / or components of medical devices (especially artificial respiration devices).

[0028] Other aspects of the invention relate to computer programs and computer-readable media storing the computer programs thereon.

[0029] The computer program includes instructions that, when implemented by a control unit (e.g., a processor of the control unit) described above and below, cause the control unit to perform the methods described above and below.

[0030] Computer-readable media can be volatile or non-volatile data storage. For example, a computer-readable medium can be a hard disk, a USB storage device (USB = universal serial bus), RAM (random-access memory), ROM (read-only memory), EPROM (erasable programmable read-only memory), EEPROM (electrically erasable programmable read-only memory), flash memory, or a combination of at least two of the above examples. A computer-readable medium can also be a data communication network or the cloud that enables the downloading of program code (e.g., via the Internet).

[0031] It should be noted that the features of the methods described above and below can also be features of computer programs and / or computer-readable media (and vice versa).

[0032] Various embodiments of the present invention are described below. These embodiments should not be construed as limiting the scope of the present invention.

[0033] According to one embodiment, the method may further include, when the breathing air humidifier is turned on: after the breathing air humidifier has been operating in a preparation mode, switching the breathing air humidifier to a humidification mode and operating the breathing air humidifier in the humidification mode, for example, until the breathing air humidifier is turned off again. In other words, the breathing air humidifier may automatically switch to the humidification mode after the preparation mode. For example, the breathing air humidifier may operate in the preparation mode until (e.g., by the control unit of the breathing air humidifier) ​​a specific switching condition for switching the breathing air humidifier to the humidification mode is recognized. Such a switching condition may be, for example, the end of a predetermined operating time in the preparation mode from the time the breathing air humidifier is turned on or off, and / or the internal temperature of the breathing air humidifier reaches a predetermined temperature. It is feasible that the breathing air humidifier switches to the preparation mode only once each time it is turned on, and after the breathing air humidifier switches to the humidification mode, it can only switch back to the preparation mode when the breathing air humidifier is turned off or turned on again after being turned off.

[0034] According to one embodiment, the method may further include, when the breathing air humidifier is turned on or off: receiving a temperature value indicating the current temperature of the breathing air inside the breathing air humidifier; comparing the temperature value with a threshold value indicating a temperature threshold at which the breathing air feels just comfortable when inhaled; and when the temperature value exceeds the threshold value, switching the breathing air humidifier to a ready mode and operating the breathing air humidifier in the ready mode. In other words, the switching of the breathing air humidifier to the ready mode can be temperature-controlled. This has the advantage that the breathing air humidifier only operates in the ready mode when actually needed. The temperature value can be a measured value (i.e., a value determined by means of a temperature sensor) and / or an estimated value.

[0035] Additionally or alternatively, the breathing air humidifier may be prevented from switching to ready mode when the temperature value does not exceed the threshold.

[0036] According to one embodiment, the method may further include, when the breathing air humidifier is turned on: if the temperature value does not exceed a threshold, switching the breathing air humidifier to humidification mode and operating the breathing air humidifier in humidification mode, for example, until the breathing air humidifier is turned off again. In other words, as long as the breathing air inside the breathing air humidifier has been sufficiently cooled since the last operation in humidification mode, the breathing air humidifier can be directly switched to humidification mode upon startup. This avoids unnecessary activation of the preparation mode.

[0037] According to one implementation, the temperature value can be received in multiple successive time steps, and compared with a threshold in each time step. Here, the breathing air humidifier can operate in a preparation mode until the temperature value no longer exceeds the threshold in one of the time steps. This achieves automatic, temperature-based termination of the preparation mode, for example, in conjunction with the breathing air humidifier automatically switching from preparation mode to humidification mode. Conversely, for example, the breathing air humidifier automatically switching from humidification mode to preparation mode can occur as described above, as a response to the breathing air humidifier being turned off or turned off and then on again.

[0038] According to one embodiment, the method may further include: calculating a temperature value using a mathematical model of a breathing air humidifier. Here, at least one input value may be received and input into the mathematical model. The mathematical model may be configured to convert the at least one input value into a temperature value and output the temperature value as an output value. The at least one input value may, for example, represent at least one of the following parameters:

[0039] • The (current) heating power of the heating element;

[0040] • The (current) liquid level of the container used to store liquids (such as water or aqueous liquids) for humidifying breathing air;

[0041] • At least one (e.g., average) duration of a heating phase prior to on or off, during which the heating element is activated;

[0042] • At least one (e.g., average) duration of a cooling phase prior to on or off, during which the heating element is deactivated;

[0043] • The (current) ambient temperature in the environment of the breathing air humidifier;

[0044] • The (current) relative humidity of the air relative to the (current) ambient temperature in the environment of the breathing air humidifier;

[0045] • Current ambient pressure in the environment of the breathing air humidifier.

[0046] "Input value" can be understood as a measured and / or estimated value that quantifies the corresponding parameter. At least one input value may be received and input into the mathematical model at multiple successive time steps. Here, the mathematical model may output a temperature value at each time step as an output value corresponding to one or more input values ​​for that time step. This implementation enables the determination of temperature values ​​with sufficient accuracy even without using a separate temperature sensor.

[0047] According to one embodiment, operation of the breathing air humidifier in a ready mode may include: generating a control signal to control at least one electro-pneumatic actuator to generate an airflow for dissipating excess heat through a breathing air inlet and / or through a breathing air outlet and / or through at least one ventilation opening of the breathing air humidifier separate from the breathing air inlet and breathing air outlet.

[0048] Ventilation openings may be constructed, for example, within the housing of a breathing air humidifier and / or the housing of a respirator. "Electropneumatic actuator" in this context is generally understood to be an electrically controllable actuator for controlling airflow. For example, an electropneumatic actuator could be a fan and / or an electrically controllable valve (such as a solenoid valve). With this active cooling, the cooling of the breathing air humidifier can be significantly accelerated compared to embodiments with only passive cooling.

[0049] According to one embodiment, operation of the breathing air humidifier in a ready mode may include: generating a control signal to control at least one electro-pneumatic actuator to prevent the supply of breathing air at the breathing air outlet. In this way, the patient is prevented from inhaling breathing air that may be overheated and / or overhumidified.

[0050] According to one embodiment, operation of a breathing air humidifier in a preparation mode may include generating a control signal to control at least one electro-pneumatic actuator to deliver breathing air at the breathing air outlet with (significantly) lower pressure and / or (significantly) lower volumetric flow and / or a different flow direction compared to operation of the breathing air humidifier in humidification mode. Due to the lower pressure and / or lower volumetric flow, the breathing air (even if it should not be sufficiently cooled) may be prevented from feeling abnormally warm and / or humid upon inhalation. The volumetric flow or pressure in the preparation mode may, for example, differ from the volumetric flow or pressure in the humidification mode by at least 5%, at least 10%, at least 20%, or at least 50%. The flow direction in the preparation mode may be opposite to the flow direction in the humidification mode. In other words, it is feasible that in preparation mode, breathing air is inhaled at the breathing air outlet, rather than being blown out as in humidification mode. In this way, the patient is prevented from inhaling breathing air that may be excessively hot and / or excessively humid.

[0051] According to one embodiment, operation of the breathing air humidifier in a preparation mode may include: generating a control signal to control at least one electro-pneumatic actuator to cause the volumetric flow of breathing air supplied at the breathing air outlet to follow a partially or continuously increasing volumetric flow curve, and / or to cause the pressure of the breathing air supplied at the breathing air outlet to follow a partially or continuously increasing pressure curve. In other words, the volumetric flow or pressure, or both, in the preparation mode may be increased in a delayed manner (e.g., gradually). This (at least partially) increasing curve enables timely removal of the mask or nasal cannula connected to the breathing air outlet for the patient in cases where the breathing air from the mask or nasal cannula feels abnormally warm and / or humid upon inhalation. Conversely, in humidification mode, one or more electro-pneumatic actuators may be controlled, for example, to produce a constant curve for the volumetric flow and / or pressure.

[0052] For example, when continuing high-flow therapy, a reduced airflow can be initially provided at the breathing air outlet. To this end, the corresponding fan can be activated very slowly, ensuring that the resulting airflow remains below what is actually required for high-flow therapy for an appropriate period of time. At the corresponding patient interface, the mixing of breathing air with ambient air ensures that the inhaled air mixture does not exceed a critical temperature.

[0053] According to one embodiment, operation of a breathing air humidifier in preparation mode may include: generating a control signal to control at least one electro-pneumatic actuator to cause the volumetric flow of breathing air supplied at the breathing air outlet to reach a final value at the end of operation of the breathing air humidifier in preparation mode, the final value being equal to or less than a volumetric flow setpoint that the breathing air humidifier should have at the start of operation in the subsequent humidification mode. For example, the volumetric flow in preparation mode may gradually increase to the volumetric flow setpoint or to a value slightly smaller than the volumetric flow setpoint (e.g., up to 10% or up to 5%). This avoids uncomfortable volumetric flow fluctuations when switching from preparation mode to humidification mode.

[0054] According to one embodiment, operation of a breathing air humidifier in preparation mode may include: generating a control signal to control at least one electro-pneumatic actuator to ensure that the pressure of the breathing air supplied at the breathing air outlet reaches a final value at the end of operation in preparation mode, which is equal to or less than a pressure setpoint that the breathing air humidifier should have at the start of operation in the subsequent humidification mode. For example, the pressure in preparation mode may be gradually increased to the pressure setpoint or to a value slightly lower than the pressure setpoint (e.g., up to 10% or up to 5%). This avoids potentially uncomfortable pressure fluctuations when switching from preparation mode to humidification mode.

[0055] According to one embodiment, the breathing air humidifier may further include a respirator hose that can be heated by means of an electric hose heating device for connection to a breathing air outlet. When the breathing air humidifier is in operation, the respirator hose is connected to the breathing air outlet. The breathing air humidifier may also be configured to additionally temperature the breathing air flowing through the respirator hose in humidification mode by means of the hose heating device. This, for example, can prevent the breathing air from becoming excessively cooled in its path from the breathing air outlet to the respirator hose of the breathing device of the patient being artificially ventilated. In this case, the method may further include preventing the activation of the hose heating device as long as the breathing air humidifier is operating in a ready mode. In this way, undesirable additional heating can be avoided for breathing air flowing through the respirator hose in ready mode that may already be abnormally humid and / or abnormally warm.

[0056] According to one embodiment, when the humidifier switches to a ready mode, a warning indication may also be generated to alert the user. The warning indication may be, for example, a visual and / or auditory and / or tactile indication. The warning indication may be presented via the humidifier itself and / or via a peripheral device wirelessly and / or wiredly connected to the humidifier for data communication (e.g., via the Internet). Such a peripheral device may be, for example, a medical device (especially a ventilator), a smartphone, smartwatch, tablet, laptop, or personal computer. For example, the warning indication may prompt the user to remove the mask or nasal cannula connected to the breathing air outlet, thereby preventing the user's respiratory tract from coming into contact with potentially overheated and / or overhumidified breathing air.

[0057] According to one embodiment, the activation of the heating element can be prevented as long as the humidifier is operating in standby mode. For this purpose, the heating element can be isolated from the power supply via a separate switch, for example. This prevents accidental activation of the heating element while the humidifier is operating in standby mode.

[0058] According to one embodiment, the breathing air humidifier may further include: a breathing air passage for guiding breathing air between a breathing air inlet and a breathing air outlet; and a container for storing a liquid (e.g., water or an aqueous liquid) for humidifying the breathing air. Here, a heating element may be configured to heat the liquid in the container. Accordingly, the breathing air humidifier may be configured to contact the breathing air with the liquid in an evaporating and / or heated state as it flows through the breathing air passage. Thus, the breathing air can be humidified before it flows out from the breathing air outlet.

[0059] In addition, the breathing air humidifier may include one or more electro-pneumatic actuators for controlling the flow of breathing air through the breathing air channel. Attached Figure Description

[0060] Embodiments of the present invention will now be described in conjunction with the accompanying drawings. Neither the description nor the drawings should be construed as limiting the scope of the invention.

[0061] Figure 1 A breathing air humidifier according to one embodiment of the present invention is shown.

[0062] Figure 2 A flowchart of a method according to one embodiment of the present invention is shown.

[0063] The accompanying drawings are schematic and not to scale. When the same reference numerals are used in different drawings, these reference numerals indicate features that have the same or identical function. Detailed Implementation

[0064] Figure 1 A breathing air humidifier 1 for use in conjunction with a ventilator is shown. In this embodiment, the breathing air humidifier 1 includes: a breathing air inlet 3 for connecting to the ventilator to allow breathing air from the ventilator to flow into the interior of the breathing air humidifier 1; a breathing air outlet 5; a breathing air passage 7 for guiding the breathing air between the breathing air inlet 3 and the breathing air outlet 5; a container 8 for storing a liquid (e.g., water or an aqueous liquid) for humidifying the breathing air; and an electric heating element 9 for heating the liquid from the container 8. The breathing air humidifier 1 is configured such that the breathing air comes into contact with the liquid in an evaporating and heated state as it flows through the breathing air passage 7 from the breathing air inlet 3 to the breathing air outlet 5, thereby humidifying (and temperature-regulating) the breathing air before it flows out of the breathing air outlet 5. For example, by correspondingly controlling the heating element 9, the breathing air can be heated to a specific comfort temperature during humidification, at which the breathing air feels warm and comfortable when inhaled. The breathing air outlet 5 can be connected to the patient's respiratory system via one or more artificial respiration hoses and / or suitable patient interfaces (such as artificial respiration masks, nasal cannulas, or catheters) to enable artificial respiration of the patient using breathing air from the breathing air humidifier 1.

[0065] Furthermore, the breathing air humidifier 1 may include at least one electro-pneumatic actuator 11 for controlling the breathing airflow 13 through the breathing air passage 7. The actuator 11 may be, for example, a fan and / or an electrically controllable valve. It is feasible that the actuator 11 (or at least one actuator 11) is arranged within the housing of the breathing air humidifier. However, the actuator 11 (or at least one of the actuators 11) may also be arranged within the housing of the artificial respiration device.

[0066] The breathing air humidifier 1 also includes a control unit 15 for controlling the operation of the breathing air humidifier 1. The control unit 15 may be implemented as a component of the breathing air humidifier 1 and / or disposed within the housing of the breathing air humidifier 1. However, the control unit 15 may also be implemented as a component of a respirator and / or disposed within the housing of a respirator.

[0067] The control unit 15 can be configured to switch the breathing air humidifier 1 between a humidification mode and a preparation mode, wherein the preparation mode is used to prepare the breathing air humidifier 1 for operation in the humidification mode. The breathing air humidifier 1 can be configured to humidify the breathing air input at the breathing air inlet 3 (here via a respirator) in the humidification mode, wherein the breathing air is temperature-controlled by means of a heating element 9 and provided in a humidified state as a breathing air flow 13 at the breathing air outlet 5, for example by correspondingly controlling an actuator 11 (or multiple actuators 11).

[0068] The control unit 15 may include, for example, a processor 17 and a memory 19, in which a computer program for operating the breathing air humidifier 1 may be stored. The processor 17 may be configured to implement the following method M (see...) by implementing the computer program. Figure 2 ).

[0069] In the first step S1, when the patient briefly interrupts or wants to interrupt artificial respiration for some reason (e.g., for a duration between 30 seconds and 3 minutes), the opening or closing of the breathing air humidifier 1 is detected, for example, manually opening or closing.

[0070] In response to the detection of opening or closing in step S1, the breathing air humidifier 1 is switched to the preparation mode in step S2 and runs for a specific period of time in the preparation mode to actively and / or passively dissipate excess heat generated inside the breathing air humidifier 1 (e.g. from the breathing air channel 7) due to the opening or closing of the breathing air humidifier 1 after it has been running in the humidification mode.

[0071] If the activation of the breathing air humidifier 1 is detected in step S1, the (activated) breathing air humidifier 1 may, for example, automatically switch to humidification mode immediately following operation in the preparation mode in step S3, and operate in humidification mode until the breathing air humidifier 1 is turned off again. Alternatively, after the preparation mode ends, the user may be prompted to switch the breathing air humidifier 1 to humidification mode by generating corresponding auditory and / or visual and / or tactile operating instructions via the breathing air humidifier 1 and / or the artificial respiration device.

[0072] If the humidifier 1 is detected to be off in step S1, the humidifier 1 may remain off after its operation in the preparation mode without further reaction. Therefore, it is feasible for the humidifier 1 (even if it is off) to run in the preparation mode for a defined duration immediately after being turned off to allow for adequate cooling and / or accelerated cooling, and then be (manually) turned on again, for example, because the patient wants to continue artificial respiration therapy.

[0073] Practically speaking, the breathing air humidifier 1 may include an additional battery for powering the breathing air humidifier 1 in a turned-off state (e.g., when operating in a ready mode). The additional battery may be, for example, rechargeable. In this case, the breathing air humidifier 1 may be configured to charge the additional battery in a turned-on state (e.g., when operating in a ready mode and / or humidification mode). In this way, it can be ensured that the battery has sufficient charge each time the breathing air humidifier 1 is turned off.

[0074] It is feasible to switch to the preparation mode each time the breathing air humidifier 1 is turned on or off (firstly). Here, the breathing air humidifier 1 may, for example, run in the preparation mode for a fixed, pre-given running time, preferably between 30 seconds and 5 minutes.

[0075] Alternatively, the switch to preparation mode in step S2 can be based on temperature. Furthermore, it is also possible that the operating time of the breathing air humidifier 1 in preparation mode can be controlled based on temperature.

[0076] Therefore, in optional step S4, in response to the detection of opening or closing in step S1, the control unit 15 may receive a temperature value indicating the current temperature of the breathing air inside the breathing air humidifier 1 (e.g., in the breathing air channel 7). This temperature value may be measured and / or estimated.

[0077] In step S5, the temperature value can be compared with a predetermined threshold. This threshold indicates the temperature at which the breathing air feels just comfortable when inhaled. This threshold can be stored, for example, in memory 19. The threshold can be fixed and pre-defined, or it can be set by the appropriate user through a suitable user interface.

[0078] If the comparison result in step S5 is that the temperature value exceeds the threshold (i.e., the current temperature is higher than the temperature threshold), then in step S2, the breathing air humidifier 1 can be switched to the preparation mode and run in the preparation mode.

[0079] Conversely, if the comparison result in step S5 indicates that the temperature value does not exceed the threshold (i.e., the current temperature is equal to or lower than the temperature threshold), switching to the preparation mode can be prevented. Instead, the breathing air humidifier 1 can, for example, switch to the humidification mode immediately after being turned on in step S3 and operate in the humidification mode, preferably until the breathing air humidifier 1 is turned off again.

[0080] Feasibly, in step S4, starting from the identification of on / off in step S1, temperature values ​​are received in multiple successive time steps. Here, the temperature value at each time step can be compared with a threshold in step S5. This achieves temperature-controlled operation time in the preparation mode, in such a way that operation in the preparation mode automatically ends once the temperature value no longer exceeds the threshold. For example, the (on) breathing air humidifier 1 can automatically switch from preparation mode to humidification mode when the temperature value no longer exceeds the threshold.

[0081] The temperature value can preferably be an estimated value. This has the following advantages: it eliminates the need for a separate temperature sensor to detect the current temperature inside the breathing air humidifier 1 (e.g., in the breathing air channel 7), which can reduce production costs.

[0082] For example, in additional step S6, a suitable mathematical model can be used to calculate a temperature value that approximately reflects the specific physical characteristics of the breathing air humidifier. To this end, the control unit 15 can receive at least one measured and / or estimated input value and input it into the mathematical model. The mathematical model can be configured to convert at least one input value into a corresponding temperature value and output that temperature value as an output value. This output value can be further processed in a suitable manner within the control unit 15.

[0083] Input values ​​can be defined as one of the following parameters:

[0084] • Current heating power of heating element 9;

[0085] • Current liquid level in container 8;

[0086] • At least one (e.g., average) duration of a heating phase prior to being turned off or on, during which the heating element 9 is activated;

[0087] • At least one (e.g., average) duration of a cooling phase prior to being turned off or on, during which heating element 9 is deactivated;

[0088] • The current ambient temperature in the environment of the breathing air humidifier 1;

[0089] • Current relative humidity relative to the current ambient temperature in the environment of the breathing air humidifier 1;

[0090] • Current ambient pressure in the environment of the breathing air humidifier 1.

[0091] It is feasible to simultaneously input multiple input values ​​of at least two different parameters (e.g., at least two of the parameters listed above) into the mathematical model to calculate the temperature value.

[0092] The mathematical model can be stored in memory 19, for example, in the form of mathematical functions and / or lookup tables. The parameters of the mathematical model can be obtained, for example, through experimentation.

[0093] The operation of the breathing air humidifier 1 in the preparation mode can also be limited to preventing the breathing air humidifier 1 from switching to the humidification mode and / or preventing the heating element 9 from activating. This achieves controlled passive heat dissipation.

[0094] Additionally or alternatively, controlled active cooling is achieved. To this end, the control unit 15 may generate one or more control signals 21, for example, during operation of the breathing air humidifier 1 in the ready mode, to control one or more actuators 11.

[0095] By means of a control signal 21 (or multiple control signals 21), an actuator 11 (or multiple actuators 11) can be controlled, for example, such that:

[0096] • Generate breathing airflow 13 to dissipate excess heat through breathing air inlet 3 and / or through breathing air outlet 5 and / or through at least one ventilation opening of breathing air humidifier 1 that is separate from breathing air inlet 3 and breathing air outlet 5.

[0097] • Prevent the supply of breathing air at breathing air outlet 5;

[0098] • Breathing air supplied at breathing air outlet 5 with lower pressure and / or smaller volume flow and / or different flow direction compared to breathing air humidifier 1 when it is operating in humidification mode;

[0099] • The volumetric flow of breathing air supplied at the five breathing air outlets follows at least a partially increased volumetric flow curve;

[0100] • The pressure of the breathing air supplied at the five breathing air outlets follows at least a partially increased pressure curve;

[0101] • The volume flow of breathing air supplied at breathing air outlet 5 reaches a final value at the end of operation of breathing air humidifier 1 in preparation mode. This final value is equal to or only slightly less than (e.g., up to 10% or up to 5%) the volume flow set value that breathing air humidifier 1 should have at the start of operation in the next humidification mode.

[0102] • The pressure of the breathing air supplied at breathing air outlet 5 reaches a final value when the breathing air humidifier 1 finishes operating in the preparation mode. This final value is equal to or only slightly less than (e.g., up to 10% or up to 5%) the pressure setting value that the breathing air humidifier 1 should have at the start of the next humidification mode operation.

[0103] The control possibilities listed above can be implemented individually or in combination, wherein at least two of the listed control possibilities can be combined with each other.

[0104] Additionally, in step S2, a suitable warning indication may be generated to alert the relevant user, such as warning that the breathing air may feel too humid and / or too hot upon inhalation. This warning indication may also require the relevant user to perform specific actions, such as waiting a moment and / or removing the artificial respiration mask or nasal cannula until the breathing air has cooled sufficiently.

[0105] A breathing hose (or multiple breathing hoses connected to the breathing air outlet 5) can be selectively heated by means of an electric hose heating device. In this case, the breathing air humidifier 1 (e.g., control unit 15) can be configured to additionally adjust the temperature of the breathing air flowing through the breathing hose by controlling the hose heating device in humidification mode. Accordingly, method M may include an additional step in which activation of the hose heating device is prevented as long as the breathing air humidifier 1 is operating in preparation mode. In this way, breathing air that may be over-humidified and / or overheated while flowing through one or more breathing hoses in preparation mode can be prevented from being undesirably additionally heated.

[0106] Finally, it should be noted that terms such as “having,” “including,” “containing,” and “with” do not exclude other elements or steps, and the indefinite article “a” or “one” does not exclude plural forms.

[0107] Furthermore, it should be noted that the features or steps described with reference to the above embodiments can also be used in combination with the features or steps described with reference to other above embodiments.

[0108] The reference numerals in the claims should not be construed as limiting the scope of the subject matter defined by the claims.

[0109] List of reference numerals

[0110] 1. Breathing air humidifier

[0111] 3. Breathing air inlet

[0112] 5. Breathing air outlet

[0113] 7 Breathing air passage

[0114] 8 containers

[0115] 9 electric heating elements

[0116] 11 Electro-pneumatic actuators

[0117] 13 Breathing airflow

[0118] 15 Control Unit

[0119] 17 processors

[0120] 19. Memory

[0121] 21 Control Signals

[0122] M method

[0123] S1 identifies whether it is on or off.

[0124] S2 switches to ready mode

[0125] S3 switches to humidification mode

[0126] S4 Receive Temperature Value

[0127] S5 Comparison Temperature Value

[0128] S6 Calculate temperature value

Claims

1. A method (M) for operating a breathing air humidifier (1), wherein, The breathing air humidifier (1) includes a breathing air inlet (3), a breathing air outlet (5), and an electric heating element (9), wherein the breathing air humidifier (1) can switch between a humidification mode and a preparation mode, the preparation mode being used to prepare the breathing air humidifier (1) for operation in the humidification mode, and the breathing air humidifier is configured to humidify the breathing air input at the breathing air inlet (3) in the humidification mode, wherein the breathing air is temperature-adjusted by means of the heating element (9) and provided at the breathing air outlet (5) in such a humidified state, wherein the method (M) includes: When the breathing air humidifier (1) is turned on or off: the breathing air humidifier (1) is switched (S2) to the preparation mode and the breathing air humidifier (1) is run in the preparation mode so that the excess heat generated by the breathing air humidifier (1) after it is turned on or off in the humidification mode is dissipated from the inside of the breathing air humidifier (1), wherein the heating element (9) is in a deactivated state.

2. The method (M) according to claim 1, further comprising, when the breathing air humidifier (1) is turned on: After the breathing air humidifier (1) is running in the preparation mode, the breathing air humidifier (1) is switched (S3) to the humidification mode and the breathing air humidifier (1) is run in the humidification mode.

3. The method (M) according to any one of the preceding claims, further comprising, when the breathing air humidifier (1) is turned on or off: Receive (S4) a temperature value, which indicates the current temperature of the breathing air inside the breathing air humidifier (1); The temperature value is compared with a threshold (S5), the threshold indicating a temperature threshold under which the breathing air feels just comfortable when inhaled; When the temperature value exceeds the threshold: switch the breathing air humidifier (1) to the preparation mode (S2) and run the breathing air humidifier (1) in the preparation mode.

4. The method (M) according to claim 3, further comprising: When the breathing air humidifier (1) is turned on: If the temperature value does not exceed the threshold: switch the breathing air humidifier (1) to the humidification mode (S3) and operate the breathing air humidifier (1) in the humidification mode.

5. The method (M) according to claim 3 or 4, in, The temperature value is received in a plurality of successive time steps and compared with the threshold in each time step, wherein the breathing air humidifier (1) operates in the preparation mode until the temperature value no longer exceeds the threshold in one of the time steps.

6. The method (M) according to any one of claims 3 to 5, further comprising: The temperature value is calculated (S6) using the mathematical model of the breathing air humidifier (1), wherein at least one input value is received and input into the mathematical model, wherein the mathematical model converts the at least one input value into the temperature value and outputs the temperature value as an output value, wherein the at least one input value represents at least one of the following parameters: The heating power of the heating element (9); The liquid level of the container (8) used to store the liquid for humidifying the breathing air; The duration of at least one heating phase prior to on or off, during which the heating element (9) is activated; The duration of at least one cooling phase prior to on or off, during which the heating element (9) is deactivated; The ambient temperature in the environment of the breathing air humidifier (1); The relative air humidity relative to the ambient temperature in the environment of the breathing air humidifier (1); The ambient pressure in the environment of the breathing air humidifier (1).

7. The method (M) according to any one of the preceding claims, in, The operation of the breathing air humidifier (1) in the preparation mode includes: A control signal (21) is generated to control at least one electro-pneumatic actuator (11) to generate an airflow (13) through the breathing air inlet (3) and / or through the breathing air outlet (5) and / or through at least one ventilation opening of the breathing air humidifier (1) that is separate from the breathing air inlet (3) and the breathing air outlet (5) to dissipate the excess heat.

8. The method (M) according to any one of the preceding claims, in, The operation of the breathing air humidifier (1) in the preparation mode includes: A control signal (21) is generated to control at least one electro-pneumatic actuator (11) to prevent the supply of breathing air at the breathing air outlet (5); and / or A control signal (21) is generated to control at least one electronic pneumatic actuator (11) to provide breathing air at the breathing air outlet (5) at a lower pressure and / or a lower volume flow and / or a different flow direction compared to when the breathing air humidifier (1) is operating in the humidification mode.

9. The method (M) according to any one of the preceding claims, in, The operation of the breathing air humidifier (1) in the preparation mode includes: A control signal (21) is generated to control at least one electro-pneumatic actuator (11) such that the volume flow of the breathing air provided at the breathing air outlet (5) follows at least a partially increased volume flow curve, and / or the pressure of the breathing air provided at the breathing air outlet (5) follows at least a partially increased pressure curve.

10. The method (M) according to any one of the preceding claims, in, The operation of the breathing air humidifier (1) in the preparation mode includes: A control signal (21) is generated to control at least one electro-pneumatic actuator (11) so that the volume flow of the breathing air supplied at the breathing air outlet (5) reaches a final value at the end of operation of the breathing air humidifier (1) in the preparation mode, the final value being equal to or less than the volume flow set value that the volume flow should reach at the start of the subsequent operation of the breathing air humidifier (1) in the humidification mode; and / or A control signal (21) is generated to control at least one electronic pneumatic actuator (11) so that the pressure of the breathing air supplied at the breathing air outlet (5) reaches a final value at the end of the operation of the breathing air humidifier (1) in the preparation mode, the final value being equal to or less than the pressure set value that the pressure should reach at the start of the subsequent operation of the breathing air humidifier (1) in the humidification mode.

11. The method (M) according to any one of the preceding claims, in, The breathing air humidifier (1) also includes an artificial breathing hose that can be heated by means of an electric hose heating device for connection to the breathing air outlet (5); The method (M) further includes preventing the activation of the hose heating device as long as the breathing air humidifier (1) is operating in the preparation mode.

12. A control unit (15) configured to implement the method (M) according to any one of the preceding claims.

13. A breathing air humidifier (1) comprising a breathing air inlet (3), a breathing air outlet (5), an electric heating element (9), and a control unit (15) according to claim 12, wherein, The breathing air humidifier (1) can switch between a humidification mode and a preparation mode. The preparation mode is used to prepare the breathing air humidifier (1) for operation in the humidification mode. The breathing air humidifier is configured to humidify the breathing air input at the breathing air inlet (3) in the humidification mode, wherein the breathing air is temperature-controlled by means of the heating element (9) and provided at the breathing air outlet (5) in such a humidified state.

14. A computer program comprising instructions that, when the control unit (15) according to claim 12 executes the computer program, cause the control unit (15) to execute the method (M) according to any one of claims 1 to 11.

15. A computer-readable medium having a computer program stored thereon according to claim 14.

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