Dynamically adaptive airway stabiliser

Abstract

The invention relates to a dynamically adaptive airway stabiliser (1) comprising: - a flow channel (2) for guiding the expired air of a patient, wherein the flow channel (2) has three successive flow channel portions (3, 4, 5) and the first flow channel portion (3) is in the form of a mouthpiece; - a measuring unit (9) for determining a measured value of the volumetric breathing flow in the second flow channel portion (4); - an adjustment element (12) for changing the flow resistance of the third flow channel portion (5); - an evaluation and control unit (11) for evaluating the determined measured value and for controlling the adjustment element (12).

Description

[0001] Dynamic adaptive respiratory stabilizer

[0002] The present invention relates to a dynamically adaptive airway stabilizer according to the features of claim 1.

[0003] In patients with respiratory diseases such as chronic obstructive pulmonary disease (COPD), pulmonary emphysema, or softening of the cartilage in the airways (e.g., polychondritis), a coughing fit can cause the airways to collapse due to damage to the bronchi during exhalation. The airways collapse. This means that more air can be inhaled than is exhaled. The air accumulates in the lungs and causes shortness of breath. This is known as dynamic hyperinflation and limits the exercise tolerance of many patients. The collapse region can be in the small airways (COPD) or in the large central airways (tracheomalacia). The more forcefully patients try to exhale by increasing the pressure in the chest, the more they compress the airways, as the external pressure is greater than the internal pressure of the airway. This compression is maximal when coughing.The walls of the airways can touch each other during collapse, leading to renewed coughing. These attacks of forced breathing and coughing lead to severe shortness of breath because exhalation becomes difficult and the overinflated lungs can no longer release carbon dioxide and absorb oxygen.

[0004] To counteract this air congestion, the patient can apply a so-called "pursed-lip technique." This involves pursed lips during exhalation, meaning the mouth is pursed and the lips are only lightly touching each other, creating a narrow gap between the lips and reducing the free airflow area at the mouth. The resulting flow resistance maintains positive intrabronchial pressure, which splints the airways and protects the patient from expiratory collapse.

[0005] However, this technique has two major disadvantages. First, when experiencing respiratory distress, the patient is often physically and psychologically unable to bring their lips together in a controlled manner. Second, it is difficult for the patient to assess exactly how the lips need to be shaped to create an optimal flow cross-section and thus an optimal pressure increase.

[0006] An alternative treatment, which also uses flow resistance to develop positive intrabronchial pressure, is offered by portable airway stabilizers. These can be carried by the patient and taken into the mouth in the event of a coughing attack. Exhaled air is expelled into the environment via the airway stabilizer. State-of-the-art airway stabilizers, however, generally have a constant flow resistance. Depending on the patient's age and constitution, and the severity of the respiratory distress or coughing attack, different flow resistances are necessary to ensure an effective increase in pressure within the patient's airways. It is important to prevent airway collapse while at the same time not making the exhalation process more difficult than necessary.Since these problems change over time and depending on the existing lung volume during breathing, continuous adaptation is necessary.

[0007] The invention is based on the object of providing an airway stabilizer which, in particular, provides an improved therapeutic result and reliably prevents airway collapse, regardless of the patient's age or constitution and regardless of the respiratory rate and depth as well as the severity of the tendency to collapse.

[0008] This object is achieved by a dynamically adaptive airway stabilizer according to the features of claim 1.

[0009] The subclaims relate to advantageous developments of the invention.

[0010] The dynamically adaptive airway stabilizer according to the invention comprises a flow channel for guiding a patient's exhaled air. The flow channel has three consecutive flow channel sections. The exhaled air passes through the flow channel sections one after the other, beginning with the first flow channel section. The third flow channel section preferably has an opening at its end so that the exhaled air can be discharged to the environment.

[0011] The first flow channel section is designed as a mouthpiece. Alternatively, a breathing mask (commonly known from CPAP devices) can be worn. In the event of a coughing fit or exertional shortness of breath, the patient can insert the mouthpiece of the airway stabilizer into their mouth or connect it to the breathing mask and exhale through the airway stabilizer. Inhalation can also occur through the airway stabilizer, or alternatively through the patient's nose.

[0012] The airway stabilizer has a measuring unit for determining a measured variable of the respiratory volume flow in the second flow channel section. The second flow channel section can, for example, have a fixed flow resistance that is higher than the flow resistance of the first flow channel section. This resistance should be low so as not to impede breathing. The pressure difference before and after the second flow channel section can be determined as a measured variable of the respiratory volume flow. The pressure difference refers to the pressure before the fixed flow resistance, i.e. in the area of ​​the first flow channel section, and the pressure after the fixed flow resistance, i.e. in the area of ​​the second flow channel section adjacent to the third flow channel section. As an alternative to the pressure difference, another measured variable correlating with the respiratory volume flow can be determined. The measured variable can be determined using alternative sensors, such asthermistors or ultrasonic sensors.

[0013] The airway stabilizer further comprises an adjusting element for varying the flow resistance of the third flow channel section. To evaluate the determined measured variable of the tidal volume flow and to control the adjusting element, the airway stabilizer comprises an evaluation and control unit. The measuring unit is connected to the evaluation and control unit. The evaluation and control unit is connected to the adjusting element.

[0014] The measured variable of the tidal volume flow determined in the measuring unit is evaluated by the evaluation and control unit and is an indicator of the patient's current breathing behavior. If the tidal volume flow determined by the evaluation unit is low, this could indicate, for example, a collapse of the airways. The evaluation and control unit transmits a signal, particularly an electrical signal, to the control element, causing it to increase the flow resistance in the third flow channel section. This, in turn, leads to an increase in pressure within the patient's airways, thus reopening the collapsed or constricted airways. As the tidal flow increases again, the braking function is reduced.

[0015] Based on the measured tidal volume flow determined by the measuring unit, the evaluation and control unit can use the control element to set the optimal flow resistance to prevent airway collapse. Since the flow resistance is adjusted depending on the patient's current breathing behavior using a correlation stored in the evaluation and control unit, the airway stabilizer can deliver improved treatment results regardless of the patient's age or constitution, and regardless of the severity of the tendency toward collapse.

[0016] If the patient inhales through the airway stabilizer, this is registered by the measuring unit and the actuator opens the flow channel so that no additional flow resistance is created.

[0017] Preferably, the airway stabilizer is designed to be portable. "Portable," as defined in the invention, means that the airway stabilizer can be carried and used by the patient without additional equipment, for example, in the patient's trouser pocket.

[0018] In an advantageous embodiment of the invention, the third flow channel section has a wall, wherein the wall is elastic at least in some regions. Elastic within the scope of the invention means that the elastic region can be deformed without destroying or damaging the material. The actuating element is designed and constructed to displace the elastic region of the wall depending on a signal from the evaluation and control unit. By displacing the elastic region accordingly, the cross-section of the flow channel, in particular, can be changed. Reducing the cross-section of the flow channel leads to an increase in pressure within the patient's airways, so that any airway collapse is resolved or prevented from the outset.

[0019] The adjusting element preferably has a clamp, in particular two clamps. The clamps are arranged in particular on opposite sides of the third flow channel section and each in the region of the elastic wall. By rotating or displacing the clamps, the elastic region of the wall can be compressed. A corresponding compression process on the opposite sides of the elastic region leads to a reduction in the cross-section of the flow channel.

[0020] In an advantageous development of the invention, the actuating element has two drive units, in particular servo motors, wherein the clamps are each coupled to one of the drive units. The clamps can be displaced via the drive units so that they displace or compress the elastic region of the wall of the third flow channel section. Coupling the clamps to separate drive units enables separate control of the individual clamps. Since the drive units have a specific drive speed due to their function, a change in the cross-section of the flow channel can be achieved significantly more quickly by using two drive units. The delay time between the transmission of the control signal and the actuating element reaching the desired end position is reduced. This enables the use of smaller, energy-saving motors, so that the unit remains portable within the meaning of the invention.

[0021] As an alternative to one or more clamps, the adjusting element can have at least one eccentric element with an eccentrically arranged pivot axis, wherein the eccentric element can be displaced against the elastic wall by pivoting, i.e. by partially twisting, about its pivot axis in order to change the flow resistance in the third flow channel section. The difference to a clamp is that the eccentric element has circumferential regions which are at different distances from the pivot axis and come into contact with the elastic wall depending on the pivot angle in order to deform it more or less. The eccentric body can have a circumferential region which is egg-shaped, at least in some regions. An egg-shaped curve has no sharp edges or jumps, so that the elastic wall cannot be damaged, wherein the egg-shaped curve conforms to the wall in some regions.On the other hand, changes in flow resistance can be achieved continuously by creating a stenosis in the third flow channel section by storing a control curve in the control system that takes the shape of the egg curve into account. The design with an eccentric element has the advantage that, with a suitable eccentric element, a sufficient stenosis can be created with just a single actuator. The number of moving parts is kept to a minimum.

[0022] Preferably, the elastic region of the wall of the third flow channel section is detachably attached to the airway stabilizer. This has the advantage that the elastic region can be replaced in the event of damage or contamination. The breathing tube or flow channel, and in particular the mouthpiece as the first flow channel section, can be designed as disposable items. All other components, in particular the control elements and the evaluation and control unit, are reusable.

[0023] In a further advantageous embodiment of the invention, the actuating element has an aperture. The aperture is in particular a disk, particularly preferably a circular disk. The aperture is arranged at least partially in the third flow channel section. The aperture can be displaced into the flow channel via an opening in a wall of the third flow channel section. The further the aperture is displaced into the opening of the wall and thus into the flow channel, the smaller the free flow cross-section within the flow channel becomes. Depending on the pressure difference determined by the measuring unit, the pressure increase within the patient's airways can be regulated by displacing the aperture. Alternatively, the aperture can be located entirely within the flow channel.

[0024] The actuator has a drive unit, in particular a servomotor, and the aperture is coupled to the drive unit. The drive unit is connected to the evaluation and control unit. Depending on the evaluation of the measured variable of the tidal volume flow determined by the measuring unit, a control signal is sent to the drive unit, so that the aperture coupled to the drive unit is moved and the free flow cross-section is thus adjusted to the patient's specific needs.

[0025] The diaphragm preferably has a diaphragm opening. By means of a displacement, in particular rotation of the diaphragm, the diaphragm opening can be moved in and out of the flow channel to adjust the free flow cross-section. The further the diaphragm opening is moved into the flow channel, the larger the resulting free flow cross-section. If the diaphragm opening is moved out again, the diaphragm blocks the previously exposed part of the flow channel. Thus, the free flow cross-section is reduced, which leads to a dynamic increase in pressure in the patient's airways. The diaphragm opening of the diaphragm is preferably drop-shaped. This has proven particularly advantageous within the scope of the invention for a uniform enlargement or reduction of the flow cross-section. Pressure peaks are avoided.

[0026] In particular, the aperture is coupled to the drive unit at its center of gravity, ensuring easy relocation of the aperture.

[0027] In a particularly advantageous design variant, the cross-sectional area of ​​the flow channel is reduced in a central region of the third flow channel section. This has the advantage that even small displacements of the aperture have a significant impact on the free flow cross-section. Pressure regulation within the patient's airways is quickly achieved. For this purpose, the wall opening is preferably located in the area of ​​the reduced cross-sectional area.

[0028] In another alternative embodiment of the invention, the third flow channel section is designed as a Tesla valve. A Tesla valve is a fluidic valve that is normally passive and thus has no moving components. It is based on the fact that the flow resistance in one flow direction is lower than in the opposite direction. This is achieved by structures that allow laminar flow in one direction but cause turbulence in the opposite direction, thus increasing the flow resistance. The Tesla valve has flow islands or flow obstacles to form the flow channel.

[0029] In this case, the Tesla valve is positioned so that flow resistance is increased when the patient exhales, while there is no significant flow resistance when inhaling. The flow islands are preferably part of the control element and are designed to be movable. By moving the flow islands, the degree of turbulence and thus the flow resistance of the flow channel can be changed. Depending on the orientation of the flow obstructions, the fluid is subjected to greater or lesser turbulence, which directly affects the flow resistance caused by the Tesla valve. The flow resistance of the third flow channel section can be adjusted via the control element depending on the measured variable of the tidal volume flow determined in the measuring unit.

[0030] Only very minor adjustments within the Tesla valve are required to achieve corresponding changes in the degree of turbulence and thus in the flow resistance. This has the advantage that very little energy is required to adjust the flow resistance.

[0031] In an alternative design of the Tesla valve, the flow islands are fixed, thus passive, and the flow resistance can be regulated by changing the cross-section of the flow channel within the Tesla valve. For example, the channel height of the Tesla valve can be increased or decreased. Depending on the channel height, the flow is laminar or turbulent, which in turn determines the flow resistance.

[0032] In a further embodiment of the invention, a variable stenosis is created in the flow channel by a pivotable throttle body arranged in the third flow channel section. The throttle body has a flow opening. It is connected to a servomotor for pivoting. Its pivot axis crosses the flow channel. Preferably, in addition to the variable stenosis (throttle body), an additional fixed stenosis in combination with a differential pressure sensor is provided. This serves to measure the actual respiratory flow. The measured variable of the respiratory volume flow is fed to the evaluation and control unit. The optimal stenosis for improving the expiratory volume is achieved through dynamic, adaptive control of the servomotor. The servomotor pivots the throttle body and the flow opening, thereby changing the flow resistance of the respiratory air.The throttle body can have a substantially cylindrical or slightly conical cross-section with a transverse bore as a flow opening. The throttle body can be referred to as a rotary valve.

[0033] The airway stabilizer preferably has a temperature control element for controlling the third flow section to a temperature of 34°C to 39°C, in particular 35.5°C to 37.5°C. Such temperature control has the advantage that the moisture contained in the exhaled air does not condense on the walls or components of the third flow channel section. Controlling the temperature of the third flow channel section to the approximate temperature of the exhaled air thus ensures that the flow channels are not impaired by condensate.

[0034] Preferably, the second flow channel section has a fixed flow resistance which is higher than the flow resistance of the first flow channel section.

[0035] In particular, a resistance element is arranged in the second flow channel section, wherein the resistance element has several through-channels. The resistance element ensures the fixed flow resistance in the second flow channel section, so that the prevailing pressure difference can be determined by the measuring unit. This design ensures that the flow is laminar and can be measured representatively.

[0036] The measuring unit is preferably a differential pressure sensor, wherein two pressure channels are coupled to the differential pressure sensor and one pressure channel is coupled to the flow channel in front of the resistance element and one pressure channel is coupled to the flow channel behind the resistance element.

[0037] Instead of a differential pressure sensor (pneumotachography principle), the measuring unit can also have a mass flow sensor. In an extended embodiment, the measuring unit can have a CO2 sensor in addition to the mass flow sensor or instead of the mass flow sensor. An overinflated lung typically shows a triangular carbon dioxide clearing curve (capnogram), whereas a deflated lung shows a rectangular clearing curve. In the airway stabilizer according to the invention, the CO2 sensor can be integrated directly into the wall of the breathing tube, e.g., in the area of ​​the mouthpiece, and connected to the control and evaluation unit. The sensors are very small, measuring e.g., 2 x 2 mm. The evaluation and control unit preferably has a microcontroller, wherein the microcontroller is connected to the measuring unit and the actuating element.The microcontroller's task is therefore to evaluate the pressure difference measured by the measuring unit and convert it into a control signal for the actuator. Depending on the patient's requirements, various correlations can be stored on the microcontroller, linking the pressure difference to the required control signal. The software, in particular, enables adaptive control, e.g., through self-learning algorithms.

[0038] Particularly preferably, artificial intelligence (AI) software is stored on the microcontroller, which continuously optimizes the correlation between the pressure difference and the control signal that regulates the flow resistance of the airway stabilizer. The goal of the dynamic airway brake in the airway stabilizer according to the invention is always to counteract dynamic airway collapse with ideal dynamic pressure without leaving increased pressure in the lungs at the end of exhalation.

[0039] In a further development of the invention, the measured values ​​are transmitted wirelessly to a mobile display unit, e.g., a tablet or smartphone, so that the patient can see the success of their airflow improvement. Instructions and motivational aids can also be displayed. The airway stabilizer has a means for wireless data transmission for this purpose.

[0040] In another embodiment, an inlet port is located on the flow channel through which oxygen can be supplied to the patient. The oxygen flow can be regulated as needed via an external valve. The valve can be controlled by the control unit of the dynamic adaptive airway stabilizer.

[0041] The invention is explained below using exemplary embodiments illustrated in purely schematic drawings. They show:

[0042] Figure 1 shows a first embodiment of a dynamically adaptive airway stabilizer in a cross-section; Figure 2 shows the first embodiment of the airway stabilizer in a

[0043] Perspective in an open state of the control element;

[0044] Figure 3 shows the first variant of the airway stabilizer in a

[0045] Perspective in a displaced state of the control element;

[0046] Figure 4 shows a second embodiment of the airway stabilizer in a cross-section;

[0047] Figure 5 shows the second embodiment of the airway stabilizer in a perspective view in an open state of the actuating element;

[0048] Figure 6 shows the second embodiment of the airway stabilizer in a perspective view in a displaced state of the actuating element;

[0049] Figure 7 shows a functional representation of a Tesla valve;

[0050] Figure 8 shows a further embodiment of an actuating element with a pivotable throttle body;

[0051] Figure 9 shows the operating principle of the throttle body;

[0052] Figure 10 shows a further embodiment of an actuating element with a

[0053] Eccentric element and

[0054] Figure 11 shows the functional principle of the eccentric body.

[0055] Figure 1 shows a dynamically adaptive airway stabilizer 1, which comprises a flow channel 2 for guiding the expiratory air of a patient (not shown in detail). The flow channel 2 has three successive flow channel sections 3, 4, 5. The patient's expiratory air first enters the first flow channel section 3, is then guided into the second flow channel section 4 and finally into the third flow channel section 5. The third flow channel 5 has an end opening 6 through which the expiratory air is released into the environment. The first flow channel section 3 is designed as a mouthpiece. If the patient experiences breathing difficulties, the airway stabilizer 1 can be inserted into the patient's mouth using the mouthpiece.The patient's lips enclose the mouthpiece in a fluid-tight manner, so that during expiration the breathing air is introduced exclusively into the airway stabilizer 1, passes through it and is then discharged to the environment.

[0056] The second flow channel section 4 has a fixed flow resistance that is higher than the flow resistance of the first flow channel section 3. The higher flow resistance is achieved by a resistance element 7 arranged in the second flow channel section 4. The resistance element 7 has a plurality of through-channels 8, so that the free cross-section of the second flow channel section 4 is reduced compared to the free cross-section of the first flow channel section 3.

[0057] The airway stabilizer 1 further comprises a measuring unit 9 for determining a measured variable of the respiratory volume flow, in this embodiment, the pressure difference before and after the second flow channel section 4. The measuring unit 9 is a differential pressure sensor, with two pressure channels 10 coupled to the measuring unit 9. One pressure channel 10 is coupled to the flow channel 2 before the resistance element 7, and one pressure channel 10 is coupled to the flow channel 2 after the resistance element 7.

[0058] The airway stabilizer 1 further comprises an evaluation and control unit 11 for evaluating the measured pressure difference of the measuring unit 9. The evaluation and control unit 11 is coupled to the measuring unit 9. The pressure difference determined by the measuring unit 9 is an indicator of the patient's current breathing behavior.

[0059] The airway stabilizer 1 further comprises an actuating element 12 for varying the flow resistance of the third flow channel section 5, wherein the evaluation and control unit 11 is designed to control the actuating element 12 depending on the evaluation of the measured pressure difference and is coupled to it. The airway stabilizer 1 thus offers the advantage that the generated flow resistance can be dynamically adapted to the patient's expiratory behavior. If, for example, a small pressure difference and thus a low expiratory volume flow is measured by the measuring unit 9, this is evaluated accordingly by the evaluation and control unit 11 and an electrical signal is sent to the actuating element 12, so that the latter increases the flow resistance of the third flow channel section 5, which leads to an increase in pressure in the patient's airways and, in turn, resolves an existing or impending airway collapse.As soon as the patient's breathing pattern is registered regularly, the flow resistance of the third flow channel section 5 is reduced again.

[0060] The third flow channel section 5 has a wall 13, wherein the wall 13 is partially elastic.

[0061] Figures 2 and 3 show that the actuating element 12 has two clamps 14, wherein the clamps 14 are arranged on opposite sides of the third flow channel section 5, each in the elastic region 15 of the wall 13. The actuating element 12 also has two drive units 16 in the form of servomotors, wherein the clamps 14 are each coupled to one of the drive units 16. The clamps 14 of the actuating element 12 are shown in an open state in Figure 2. The clamps 14 rest against the elastic region 15 of the wall 13 without displacing or compressing it. Based on a corresponding signal from the evaluation and control unit 11, the clamps 14 are displaced by the drive units 16 towards the elastic region 15 of the wall 13, so that it is compressed, which results in a reduction in the cross-section of the flow channel 2.This can be seen in Figure 3, which shows the clamps 14 in a correspondingly displaced state. The reduction in cross-section, in turn, increases the flow resistance in the third flow channel section 5 and thus in the airway stabilizer 1, which leads to an increase in pressure in the patient's airways.

[0062] Since the clamps 14 are coupled to separate drive units 16, they can be controlled or moved independently of one another. Due to their function, there is a time lag between the receipt of the control signal and the reaching of the specified end position of the clamps 14. The drive units 16 move the clamps 14 at a specific speed. By arranging two clamps 14, the flow resistance to be adjusted can be adjusted more quickly after the corresponding signal is output by the evaluation and control unit 11.

[0063] The elastic region 15 of the wall 13 of the third flow channel section 5 is detachably attached to the airway stabilizer 1. This has the advantage that the elastic region 15 can be replaced in the event of any damage, wear, or contamination, without requiring the replacement of other components of the airway stabilizer 1. As shown in Figure 1, the respective ends 17 of the elastic region 15 are pulled over the adjacent wall regions 18 of the wall 13 of the third flow channel section 5. To detach the elastic region 15 from the airway stabilizer 1, the elastic region 15 can be pulled off the adjacent wall regions 18 and then replaced.

[0064] Figure 4 shows a second embodiment of the airway stabilizer 1 in cross-section. Here, the actuating element 12 has a diaphragm 19, wherein the diaphragm 19 is arranged in sections in the third flow channel section 5 and can be displaced into the third flow channel section 5 via an opening 20 in the wall 13. The actuating element 12 has a drive unit 16, which is a servomotor. The diaphragm 19 is coupled to the drive unit 16, and the drive unit 16 is connected to the evaluation and control unit 11.

[0065] As can be seen in Figures 5 and 6, the aperture 19 has an aperture 21, and the aperture 21 can be moved in and out of the third flow channel section 5 by rotating the aperture 19 to adjust the free flow cross-section. The aperture 21 of the aperture 19 is tropical-shaped and has a smooth transition from a narrow end to a widened end.

[0066] Figure 5 shows the airway stabilizer 1 in an open state. The aperture 21 is relocated with its wider end into the flow channel 2 of the third flow channel section 5. In this state, the flow channel 2 is completely open.

[0067] Figure 6 shows the airway stabilizer 1 with the aperture 19 displaced. Here, the narrow end of the aperture opening 21 is positioned in the flow channel 2. In this state, the free flow cross-section of the third flow channel section 5 is reduced. Consequently, the flow resistance of the airway stabilizer 1 is increased, and thus also the pressure in the patient's airways. By rotating the aperture 19, the free flow cross-section in the flow channel 2 can be smoothly regulated. For this purpose, the aperture 19 is coupled to the drive unit 16 at its pivot axis 22.

[0068] Figure 4 shows that the cross-sectional area of ​​the flow channel 2 is reduced in a central region 23 of the third flow channel section 5. This has the advantage that even slight displacements of the aperture 19 have a significant impact on the free flow cross-section of the flow channel 2. For this purpose, the opening 20 of the wall 13 is arranged in the region of the reduced cross-sectional area, i.e., in the central region 23.

[0069] Figure 7 shows the basic functionality of a third embodiment of the airway stabilizer 1. In this variant, the third flow channel section 5 is designed as a Tesla valve 24.

[0070] Figures 7 a) and b) show a section of the flow channel 2 in the Tesla valve 24. Figure 7a) schematically shows the flow of the ambient air 25 when a patient inhales. The ambient air 25 enters the flow channel 2 through the end opening 6. A flow island 26 is arranged in the flow channel 2, which divides the flow channel 2 into a first flow channel 27 and a second flow channel 28. When the patient inhales, the majority of the air 25 flows along the second flow channel 28 due to the orientation of the flow island 26. Only a small portion of the ambient air 25 flows through the first flow channel 27. The first flow channel 27 and the second flow channel 28 converge again into a common flow channel 2 after the flow island 26. The ambient air 25 then flows into the second flow channel section 4.Alternatively, several of the Tesla valve sections 24 shown in Figure 7 can be passed through. The flow channel 2 is designed so that the flow profile of the ambient air 25 is laminar along the entire Tesla valve 24. No turbulence occurs, which would lead to an increase in flow resistance. Thus, the Tesla valve 24 does not impede the patient's inhalation.

[0071] Figure 7 b) shows the path of the patient's expiratory air 29 during exhalation. The ambient air 25 passes through the Tesla valve 24 in the opposite direction and is evenly distributed between the first flow channel 27 and the second flow channel 28. At the confluence of the first flow channel 27 and the second flow channel 28, the ambient air 25 flows in opposite directions. This causes turbulence in the flow, and the laminar flow pattern breaks down. The turbulence increases the flow resistance, so that pressure builds up in the patient's airways.

[0072] The flow resistance can be regulated by displacing the flow islands 26. This is shown in Figures 7 c) and d). In Figure 7 c), the flow island 26 is displaced toward the upper flow channel 27 and blocks it. Consequently, the expiratory air 29 can only flow through the second flow channel 28. The flow remains laminar, and no significant flow resistance is created. The flow island 26 can be positioned anywhere between the end positions shown in Figures 7 b) and c). This allows the flow resistance to be regulated.

[0073] In Figure 7 d), the displacement of the flow island 26 occurs by its rotation. In this case, too, the first flow channel 27 is blocked, so that the expiratory air 29 can only flow through the second flow channel 28. The flow remains laminar, and no significant flow resistance is created. The flow island 26 can be positioned anywhere between the end positions shown in Figures 7 b) and d). Thus, regulation of the flow resistance is also possible in this case. In all embodiments shown, the airway stabilizer 1 has a temperature control element 30 for controlling the temperature of the third flow channel section 5 to a temperature of 36.5°C. This temperature corresponds to the temperature of the patient's expiratory air. Appropriate temperature control prevents the moisture contained in the expiratory air from condensing in the airway stabilizer 1.This ensures that the flow channels 2 and the components remain dry and their function is not impaired. This also increases the service life of the airway stabilizer 1.

[0074] The evaluation and control unit 11 has a microcontroller, wherein the microcontroller is connected to the measuring unit 9 and the actuating element 12.

[0075] The airway stabilizer 1 also has a battery 31 which supplies the actuating element 12, the evaluation and control unit 11, the measuring unit 9 and the temperature control element 30 with power.

[0076] The actuator 12, the evaluation and control unit 11, the measuring unit 9, the temperature control element 30, and the battery 31 are arranged in a housing 32. The housing 32 is coupled to the wall 13 of the flow channel 2.

[0077] Figure 8 shows a further embodiment of an actuating element 12 with a pivotable throttle body 33. Figure 9 shows the functional principle of the throttle body 33. The throttle body 33 functions like a rotary valve in a plug valve. The throttle body 33 is cylindrical or slightly conical. It is located in the flow path of the third flow channel section 5 and has a flow opening 34. In this embodiment, it is circular. The breathing air flow can flow unhindered through the flow opening 34 in the open position (Figure 9, right). If the throttle body 33 is pivoted by up to 90°, the flow resistance in the flow channel section 5 is increased (Figure 9, left). A pivot axis 35 runs in the longitudinal direction of the throttle body 33 and therefore penetrates the flow channel section 5. The pivot axis 35 is, in particular, perpendicular to the flow channel section 5.Figure 9 shows pressure channels 10 upstream and downstream of a defined, annular constriction 38, wherein the pressure channels 10 are coupled to a measuring unit for differential pressure measurement.

[0078] Figures 10 and 11 show an adjusting element 12 with an eccentric element 36, which can be displaced by pivoting about its eccentrically arranged pivot axis 37 against the elastic region 15 of the wall 13, in order to change the flow resistance in the third flow channel section 5. This design differs from the clamps in that the pivot axis 37 does not run parallel to the longitudinal axis of the third flow channel section 5, but is at a right angle to it. Figure 11 shows a schematic functional principle. In Figure 11 on the left, the flow resistance is not increased because there is no effect on the elastic wall section 15. In Figure 11 on the right, the eccentric element 36 is pivoted by 90°. The flow resistance in the third flow channel section 5 is increased.

[0079] Reference symbol:

[0080] 1 - Airway stabilizer

[0081] 2 - Flow channel

[0082] 3 - first flow channel section

[0083] 4 - second flow channel section

[0084] 5 - third flow channel section

[0085] 6 - end opening

[0086] 7 - Resistance element

[0087] 8 - Through channels

[0088] 9 - Measuring unit

[0089] 10 - Pressure channel

[0090] 11 - Evaluation and control unit

[0091] 12 - Actuator

[0092] 13 - Wall

[0093] 14 - Terminals

[0094] 15 - elastic range of 13

[0095] 16 - Drive units

[0096] 17 - Ends of 15

[0097] 18 - adjacent wall area 18

[0098] 19 - Aperture

[0099] 20 - Opening of 13

[0100] 21 - Aperture

[0101] 22 - Swivel axis

[0102] 23 - middle range of 5

[0103] 24 - Tesla valve

[0104] 25 - Ambient air

[0105] 26 - Current Island

[0106] 27 - first flow channel

[0107] 28 - second flow channel

[0108] 29 - Exhaled air

[0109] 30 - Tempering element

[0110] 31 - Battery - Housing - Throttle body - Flow opening in 33 - Swivel axis of 33 - Eccentric element - Swivel axis of 36 - Defined constriction

Claims

Patent claims 1 . Dynamically adaptive airway stabilizer (1 ) comprising: a flow channel (2) for guiding the exhaled air of a patient, wherein the flow channel (2) has three successive flow channel sections (3, 4, 5) and the first Flow channel section (3) is designed as a mouthpiece, a measuring unit (9) for determining a measured variable of the respiratory volume flow in the second flow channel section (4), an adjusting element (12) for changing the flow resistance of the third flow channel section (5), an evaluation and control unit (11) for evaluating the determined measured variable and for controlling the adjusting element (12).

2. Dynamically adaptive airway stabilizer (1) according to claim 1, characterized in that the third flow channel section (5) has a wall (13), the wall (13) being elastic at least in some areas and the actuating element (12) being designed and constructed to displace the elastic region (15) of the wall (13) depending on a signal from the evaluation and control unit (11).

3. Dynamically adaptive airway stabilizer (1) according to claim 2, characterized in that the adjusting element (12) has a clamp (14), in particular two clamps (14), wherein the clamps (14) are preferably arranged on opposite sides of the third flow channel section (5) and each in the elastic region (15) of the wall (13).

4. Dynamically adaptive airway stabilizer (1) according to claim 3, characterized in that the actuating element (12) has two drive units (16), in particular servo motors, wherein the clamps (14) are each coupled to one of the drive units (16).

5. Dynamically adaptive airway stabilizer (1) according to claim 2, characterized in that the adjusting element (12) has at least one eccentric element (36) with an eccentrically arranged pivot axis (37), wherein the eccentric element (36) can be displaced by pivoting about its pivot axis (37) against the elastic region (15) of the wall (15) in order to change the flow resistance in the third flow channel section (5).

6. Dynamically adaptive airway stabilizer (1) according to one of claims 1 to 5, characterized in that the elastic region (15) of the wall (13) of the third flow channel section (5) is detachably attached to the airway stabilizer (1).

7. Dynamically adaptive airway stabilizer (1) according to claim 1, characterized in that the adjusting element (12) has a diaphragm (19), wherein the diaphragm (19) is arranged in the third flow channel section (5) and the diaphragm (19) is either displaceable in the flow channel (2) via an opening (20) in a wall (13) of the third flow channel section (5), or is located completely in the flow channel (2), wherein the adjusting element (12) has a drive unit (16), in particular a servo motor, and the diaphragm (19) is coupled to the drive unit (16) and the drive unit (16) is connected to the evaluation and control unit (11).

8. Dynamically adaptive airway stabilizer (1) according to claim 7, characterized in that the diaphragm (19) has a diaphragm opening (21) and the diaphragm opening (21) can be moved in and out of the flow channel (2) by means of a displacement, in particular rotation of the diaphragm (19) in order to adapt the free flow cross-section of the latter.

9. Dynamically adaptive airway stabilizer (1) according to claim 8, characterized in that the aperture (21) of the aperture (19) is drop-shaped.

10. Dynamically adaptive airway stabilizer (1) according to one of claims 7 to 9, characterized in that the diaphragm (19) is coupled to the drive unit (16) at its pivot axis (22).

11. Dynamically adaptive airway stabilizer (1) according to one of claims 7 to 10, characterized in that the cross-sectional area of ​​the flow channel (2) is reduced in a central region (23) of the third flow channel section (5).

12. Dynamically adaptive airway stabilizer (1) according to claim 11, characterized in that the opening (20) of the wall (13) is arranged in the region of the reduced cross-sectional area.

13. Dynamically adaptive airway stabilizer (1) according to claim 1, characterized in that the third flow channel section (5) is designed as a Tesla valve (24).

14. Dynamically adaptive airway stabilizer (1) according to claim 13, characterized in that the Tesla valve (24) has flow islands (26) for forming a first flow channel (27) and a second flow channel (28), wherein the flow islands (26) are part of the actuating element (12) and are designed and constructed to change the flow resistance of the flow channel (2) by means of a displacement and / or the actuating element (12) is designed and constructed to change the first flow channel (27) or the second flow channel (28) in its respective cross section.

15. Dynamically adaptive airway stabilizer (1) according to claim 1, characterized in that the adjusting element (12) has a pivotable throttle body (33) arranged in the third flow channel section (5) with a flow opening (34).

16. Dynamically adaptive airway stabilizer (1) according to one of claims 1 to 15, characterized in that the airway stabilizer (1) has a tempering element (30) for tempering the third flow channel section (5) to a temperature between 34 and 39°C, in particular between 35.5 and 37.5°C.

17. Dynamically adaptive airway stabilizer (1) according to one of claims 1 to 16, characterized in that a resistance element (7) is arranged in the second flow channel section (4), wherein the resistance element (7) has a plurality of through channels (8).

18. Dynamically adaptive airway stabilizer (1) according to claim 17, characterized in that the measuring unit (9) is a differential pressure sensor, wherein two pressure channels (10) are coupled to the measuring unit (9) and one pressure channel (10) is coupled to the flow channel (2) in front of the resistance element (7) and one pressure channel (10) is coupled to the flow channel (2) behind the resistance element (7).

19. Dynamically adaptive airway stabilizer (1) according to one of claims 1 to 17, characterized in that the measuring unit (9) has a mass flow sensor.

20. Dynamically adaptive airway stabilizer (1) according to one of claims 1 to 19, characterized in that the measuring unit (9) has a CO2 sensor.

21. Dynamically adaptive airway stabilizer (1) according to one of claims 1 to 20, characterized in that the evaluation and control unit (11) has a microcontroller, wherein the microcontroller is connected to the measuring unit (9) and the actuating element (12).

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