Mixing device, breathing or anaesthesia machine having mixing device, and method for producing mixing device

Abstract

The invention relates to a mixing device (1) for a breathing or anaesthesia machine for mixing at least two breathing gas components, having a flow channel with at least two inlets (2, 3) for introducing the breathing gas components, 3) and a second flow channel section (5) with an outlet (7) for discharging a flow of breathing gas having a breathing gas component. The mixing device (1) is characterized in that the cross-section of the first flow channel section (4) decreases downstream at least in sections in the direction of the transition (6) from the first to the second flow channel section (4, 5), the first and second flow channel sections (4, 5) are inclined to each other, and the first flow channel section (4) opens into the second flow channel section (5) in the region of the transition (6) in such a way that the first flow channel section (4) opens into the second flow channel section (5). In this way, a vortex of the breathing gas flow around the longitudinal central axis (8) is formed at least partially in the second flow channel section (5), said vortex flowing helically in the direction of the outlet (7) at least in sections. The invention further relates to a breathing or anaesthesia machine having such a mixing device (1) and to a method for producing such a mixing device (1).

Description

TECHNICAL FIELD

[0001] The invention relates to a mixing device for a breathing or anesthesia machine, a breathing or anesthesia machine with a mixing device for mixing at least two breathing gas components, and a method for producing a mixing device. BACKGROUND

[0002] When a patient is breathing through a breathing or anesthesia machine, it is a matter of supplying the patient with a breathing gas. The breathing gas is here usually a mixture of two or more breathing gas components. The most common breathing gas components in practice are air and oxygen. The breathing gas components can be obtained from different sources, for example via a central gas supply (the breathing or anesthesia machine is connected to this at the installation site), via gas bottles filled with the respective breathing gas component and / or via the aspiration of air from the surroundings by the breathing or anesthesia machine itself, the so-called blower technology.

[0003] The supplied breathing gas components are mixed in the breathing or anesthesia machine in order to achieve at least approximately homogeneous distribution of the breathing gas components. This is necessary, inter alia, in order to ensure correct monitoring of the breathing gas in the next step, which is important for the safety of the patient and for the success of the treatment, that the breathing gas concentration set at the breathing or anesthesia machine is present in the breathing gas flow. Deviations from the set proportions of the breathing gas components arise through tolerances in the concentration when the breathing gas components are supplied, in particular in the case of the use of gas bottles, through tolerances of the valves in terms of the measurement of the sensors and the flow rate. The sensors used for monitoring the properties of the breathing gas usually only detect local gas properties, such as the concentration of the respective breathing gas component at the respective measurement point. Local concentration differences can therefore lead to false measurements and trigger false alarms if, for example, the measured gas concentration is too low. It is desirable for a mixed breathing gas in which the concentration differences of the respective breathing gas components are as small as possible.

[0004] In order to produce a mixed breathing gas, mixing devices are known within breathing or anesthesia machines which have a hollow body or volume into which the breathing gas components are guided for their mixing. The dimensions of such mixing tanks are chosen such that the residence time of the breathing gas flow is at least as long as to enable the establishment of an approximately uniform concentration of the breathing gas components by diffusion. The longer residence time causes the changes in the concentration of the breathing gas components at the breathing or anesthesia machine to proceed only slowly, since the mixing tank has to be filled and traversed by the breathing gas as an additional volume. The dynamic range of a breathing or anesthesia machine with such a mixing volume when breathing is thereby limited.

[0005] Furthermore, motor-operated mixers are known from the prior art, in which the mixing of the breathing gas components is achieved, for example, by incorporating a motor-operated stirrer into the breathing or anesthesia machine and its operation. The disadvantage of this solution is the high costs for the necessary components and their operation and maintenance which are associated therewith.

[0006] The two solutions mentioned above require a relatively large space within the ventilator or anesthesia machine. This results in an unfavorable increase in the structural size of such a device.

[0007] Furthermore, static flow mixers are known from the prior art. Document US 2016082220 A1 illustrates a system for respiratory therapy with a static flow mixer. The described static flow mixer is configured to mix multiple respiratory gas components and includes an inlet and an outlet, and a first deflector plate between the inlet and outlet. Additionally, the static flow mixer includes a narrowing section disposed between a downstream edge of the first deflector plate and the nearest downstream surface, wherein the length of the narrowing section is less than the height of the first deflector plate. This technical solution should uniformly mix the respiratory gas components supplied to the static flow mixer. Other static flow mixers are known from documents EP 1312409 B1 and EP 1426099 B1. The problem with these static flow mixers is that they create additional flow resistance in the respiratory gas flow path, which adversely affects the dynamic characteristics of the respiratory or anesthesia machine. Furthermore, these static flow mixers require a large amount of structural space and have complex geometry, thus resulting in high manufacturing costs. Summary of the Invention

[0008] Based on solutions known from the prior art and the aforementioned problems, the object of the present invention is to provide a device manufactured in a simple and reliable manner for applying a mixture of respiratory gases consisting of at least two respiratory gas components in a breathing or anesthesia machine. Here, the dynamic characteristics of the breathing or anesthesia machine used for breathing should be affected as little as possible, and in particular, it should be able to induce a change in the concentration of one of the respiratory gas components at the breathing or anesthesia machine as quickly as possible and with the smallest possible pressure drop.

[0009] The aforementioned objective is achieved by a mixing device having the features of claim 1 and a breathing or anesthesia machine having a mixing device according to claim 10. Furthermore, this objective is achieved by a method for manufacturing a mixing device having the features of claim 11. Further details of the invention are derived from the dependent claims, the description, and the drawings. Here, the features and details described in conjunction with the device according to the invention are of course also considered as disclosures in conjunction with the breathing or anesthesia machine having such a mixing device according to the invention and the method according to the invention, and thus the disclosures regarding the various aspects of the invention are always referred to, and may be referred to, each other.

[0010] A mixing device for mixing at least two respiratory gas components for a breathing or anesthesia machine according to the invention comprises a flow channel having a first flow channel section with at least two inlets correspondingly suitable for introducing respiratory gas components, i.e., air and / or gas flow, and a second flow channel section with an outlet for discharging a respiratory gas flow containing the mixed respiratory gas components. The mixing device is characterized in that the cross-section of the first flow channel section decreases downstream at least segmentally in the direction of the transition from the first to the second flow channel section; the first and second flow channel sections are inclined to each other at least in the region of the transition; and the first flow channel section in the region of the transition extends into the second flow channel section such that a vortex of respiratory gas flow is at least partially formed in the second flow channel section around the longitudinal central axis of the second flow channel section, which flows at least segmentally spirally toward the outlet.

[0011] The core of this invention is the mixing of at least two respiratory gas components, representing at least a portion of an air-and / or gas flow, to produce a respiratory gas flow with a nearly uniformly distributed respiratory gas component and therefore, at least approximately, no difference in the concentration of the individual respiratory gas components across the flow cross-section. This is achieved through two sections of a flow channel according to the invention, designed and arranged such that a vortex containing the respiratory gas components is constructed in the second flow channel section, which propagates at least segmentally along the flow direction in the form of a flow spiral or flow swirl. The air-, gas-, and / or gas mixture flow in the region of the second flow channel section is thus at least partially placed in a motion rotating about the longitudinal central axis of the second flow channel section and simultaneously pointing towards the outlet of the flow channel. Here, effective mixing of the respiratory gas components occurs.

[0012] Examples of respiratory gas components are air and oxygen. However, additional gases, gas mixtures, or gas-air mixtures may also be considered for use in ventilators and / or anesthesia machines for the purpose of anesthesia and / or at least temporary sedation of the patient during respiration.

[0013] A vortex, sometimes called a eddy, refers to the rotational flow motion of a fluid about an axis of rotation, wherein the fluid moves downstream at least approximately parallel or inclined to the longitudinal direction of the axis of rotation. It can be generated, for example, by targeted diversion of the flow and / or by the application of external forces.

[0014] respiratory gas components in respiratory gas stream The conveying of [material] can usually be described by the following conveying equation: First item Describing changes over time, the second item Describes convective transport, the third item Describing diffusion transport and the last item Describe the source or sink. Diffusion transport mechanisms are relatively weak and are inhibited by long diffusion paths and small transport coefficients. For example, diffusion transport mainly occurs in mixing tanks. Therefore, a relatively long residence time of the breathing gas components in the mixing tank is required to achieve ideal mixing of different breathing gas components, leading to the aforementioned disadvantages.

[0015] Compared to diffusion transport, convection transport functions as a very strong transport mechanism. According to the invention, this transport mechanism is utilized advantageously by selectively generating eddies to mix different respiratory gas components.

[0016] Different respiratory gas components (which may be air, gas, or a mixture of gases) are introduced into the mixing device through at least two inlets. In particular, if more than two respiratory gas components are to be mixed together, more than two inlets may be considered.

[0017] The inlet, for example, is arranged at the flow channel such that the respiratory gas component flows extend side-by-side in space within the first flow channel section, forming a stratified flow of the respiratory gas components. In the region of the contact surfaces where the respiratory gas component flows are adjacent to each other, the mixing of different respiratory gas components has occurred at least partially through a diffusion process. The stratified flow of the respiratory gas components flows in the direction of the transition from the first to the second flow channel section.

[0018] Alternatively, the inlet may be arranged at the flow channel such that the respiratory gas components at least partially cross within the first flow channel section and / or deflect the flow of each respiratory gas component.

[0019] The preferentially stratified flow, i.e., the flow in which different respiratory gas components are arranged in strata, is accelerated due to the reduced cross-section of the first flow channel section and guided with a higher flow impulse into the second flow channel section, for example, tangentially, in the transition region. Tangential introduction in this case means that the stratified flow is introduced only in a portion of the inner wall of the second flow channel section, i.e., not at the center or across the entire cross-section of the second flow channel section. Here, after being introduced into the second flow channel section, the stratified flow initially flows only along a portion of the inner wall of the second flow channel section, while other areas of the inner wall have little or no contact with the stratified flow, either directly or during vortex construction. The stratified flow is approximately tangential to the inner wall of the second flow channel section upon inflow and has an asymmetrical distribution in the transition region of the second flow channel section. The reduction in the cross-section of the first flow channel section can preferably be achieved by reducing the perimeter of the first flow channel section itself, or by introducing at least one additional flow-guiding element into the first flow channel section, which deflects and guides a portion of the stratified flow through a flow channel cross-section smaller than that of the first flow channel section. Furthermore, it is conceivable that this additional element guides the stratified flow into a second flow channel section, thereby constructing a vortex as described above.

[0020] The acceleration and tangential introduction of the stratified flow (i.e., the directional introduction of the stratified flow along a portion of the inner wall of the second flow channel section) and the inclination between the first and second flow channel sections according to the invention result in the formation of vortices within the second flow channel section. The inclination of the second flow channel section relative to the first flow channel section means that their longitudinal central axes are inclined at an angle not equal to zero. Thus, the stratified flow extending at a portion of the inner wall of the second flow channel section impacts at least one inner wall region of the second flow channel section that is inclined relative to that portion, undergoing at least partial deflection and forming vortices. Furthermore, alternative to or supplementing the preferred tangential introduction, the stratified flow is introduced into the second flow channel section such that it initially extends, or only partially extends, at a portion of the inner wall or along multiple regions of the inner wall. Importantly, the stratified flow, in its further extension within the second flow channel section, at least partially impacts another inner wall region that is at least partially inclined relative to the flow direction, where it is deflected and at least partially forms vortices. For example, by guiding the accelerated, stratified flow at the center of the transition from the first to the second flow channel section, and due to the inclination of the second flow channel section relative to the first flow channel section, it impacts one of the inner wall regions of the second flow channel section during further extension.

[0021] According to the invention, the stratified flow of respiratory gas components extending in the first flow channel section is at least partially transformed into vortices in the second flow channel section, wherein multiple layers of these respiratory gas components come into close contact with each other due to the rotational motion of the vortexes, thus multiplying the number of side-by-side layers of different respiratory gas components. For example, the first two layers of two different respiratory gas components from the stratified flow generate four, six, or more layers of the two respiratory gas components in the cross-section of the vortex. That is, the respiratory gas components are distributed in the second flow channel section by means of the vortex through convective transport, and the contact surface of the different respiratory gas component flows adjacent to each other is increased, thereby enhancing the mixing of respiratory gas components by diffusion. The vortex flows at least segmentally spirally toward the outlet, where the convective transport of different respiratory gas components at the outlet advantageously constructs a mixed respiratory gas flow with a smaller structural size of the mixing device and less impact on the dynamic characteristics of the breathing or anesthesia machine.

[0022] Different respiratory gas components can be mixed in an advantageous manner using such a device. Here, compared to conventional mixing tanks in breathing or anesthesia machines, the required structural space is significantly reduced, achieving a small structural size and a large dynamic range for the breathing or anesthesia machine. Therefore, changes in settings at the breathing or anesthesia machine, such as changes in the concentration of one of the respiratory gas components, can be achieved rapidly and with minimal pressure drop. Furthermore, this structure is simpler to manufacture compared to static mixers. Compared to motor-driven mixers, there is no need for an active drive and therefore a more complex structure and increased energy consumption; the vortex is generated simply through the simpler structure of the mixing device according to the invention and existing flow patterns. Therefore, the mixing device can be manufactured in a simple manner, keeping manufacturing costs within an economically reasonable range.

[0023] In a preferred embodiment, the first and second flow channel sections are arranged approximately perpendicular to each other in the transition region. The inclination of the flow channel sections relative to each other serves to create vortices in the second flow channel section. It is particularly advantageous for the construction of vortices when the first and second flow channel sections are incised at approximately 90°. Here, the longitudinal central axes are approximately perpendicular to each other, and due to this inclination, the stratified flow of the first flow channel section impacts the edge region of the second flow channel section in the flow direction, thereby being deflected and creating vortices. When the first flow channel section is arranged approximately perpendicular to the second flow channel section, the vortex effect is particularly strong, thus also improving the mixing of different breathing gas components. Furthermore, as the flow further penetrates the second flow channel section, a particularly stable vortex is constructed, wherein the flow direction extends around the longitudinal central axis of the second flow channel section, which approximately forms the center of the vortex and thus adapts to the geometry of the second flow channel section for flow towards the outlet.

[0024] Another advantage of the near-vertical arrangement of the first and second flow channel sections is the more compact structural form and therefore space savings when loaded into a ventilator or anesthesia machine.

[0025] According to a particularly preferred embodiment of the mixing device, the first flow channel section and / or the second flow channel section have at least segmentally rectangular cross-sections. It is conceivable that the cross-section has a rectangular shape or, particularly preferably, a square shape. Advantageously, this allows for improved utilization of structural space when the mixing device is incorporated into a ventilator or anesthesia machine. Particularly advantageous is the at least partially rectangular cross-section of the second flow channel section, wherein secondary vortices are constructed through eddies at the four corners within the second flow channel section, which improves the mixing of different respiratory gas components.

[0026] In a preferred embodiment of the mixing device, the first flow channel section and / or the second flow channel section are constructed, at least segment by segment, in the form of a cylinder, a truncated cone, or a truncated pyramid. The generally circular cross-section of the first and / or second flow channel sections has the advantage that, for example, breathing gas hoses can be more easily installed at the inlet and / or outlet of the mixing device. Particularly advantageous is the at least partially circular cross-section of the second flow channel section, in which a particularly stable vortex is constructed, flowing at least segment by segment in a spiral manner and guided by the second flow channel section toward the outlet.

[0027] According to a preferred embodiment of the mixing device, the at least two inlets have an approximately circular cross-section. This has the advantage that breathing gas hoses can be installed particularly easily at the inlets.

[0028] In a preferred embodiment of the mixing device, the cross-section of the first flow channel section is reduced by more than 50% up to the transition to the second flow channel section. Preferably, the cross-section decreases uniformly from the inlet region to the transition to the second flow channel section. Furthermore, it is conceivable that the reduction in cross-section involves only a portion of the first flow channel section. For example, the cross-section is reduced by more than 50% from the center of the first flow channel section to the transition to the second flow channel section. It is also conceivable that the reduction in cross-section occurs shortly before the transition to the second flow channel section.

[0029] A particular advantage of reducing the cross-sectional area by more than 50% is that the resulting flow impulse in the stratified flow is strong enough to promote the formation of vortices in the second flow channel section. This is especially advantageous for the typical volumetric flow of ventilators or anesthesia machines in the range of 1 L / min to 180 L / min, thus generating vortices.

[0030] According to a preferred embodiment of the mixing device, the first flow channel section and / or the second flow channel section include mixing elements for mixing respiratory gas components. The mixing element may be, for example, a static mixer or a similar geometry, integrated into the first and / or second flow channel sections. Here, the stratified flow in the first flow channel section and / or the eddy currents in the second flow channel section impact the mixing element, resulting in additional mixing of the respiratory gas components. Advantageously, improved mixing of the respiratory gas components at the outlet of the mixing device is achieved by a suitable mixing element without increasing the size of the mixing device and without requiring additional structural space when incorporated into a ventilator or anesthesia machine. Here, the external dimensions of the mixing element should correspond to or be smaller than the inner circumference of the first or second flow channel section. Furthermore, the mixing element should have the lowest possible flow resistance. It is conceivable to integrate one or more mixing elements into the first and / or second flow channel sections. Furthermore, it is conceivable that the mixing elements within the mixing device have different structures.

[0031] In a preferred embodiment of the mixing device, the at least two inlets are arranged substantially side-by-side, thereby achieving stratified flow of the breathing gas components in the first flow channel section. This arrangement of the inlets results in a unique stratified flow in which the breathing gas component flows extend substantially side-by-side and maintain approximately the same velocity, i.e., the flow is not weakened. This advantageously facilitates the formation of vortices in the second flow channel section.

[0032] According to a preferred embodiment of the mixing device, at least two inlets of the first flow channel section are respectively followed by buffer volumes, and the cross-section of the buffer volumes is generally circular. Preferably, the buffer volumes are cylindrical, and the breathing gas component flow preferably flows directly into the buffer volumes from the inlets. The cross-section of the buffer volume preferably corresponds to the cross-section of the corresponding inlet, so that the corresponding buffer volume can be filled with the incoming breathing gas component as quickly as possible. Here, the buffer volume preferably has a size in the range of 25 to 35 ml, particularly preferably 30 ml. The breathing gas component flow is introduced into the corresponding buffer volume through the inlet, which is filled with the corresponding breathing gas component. As the breathing gas component flow leaves the buffer volume within the first flow channel section, a stratified flow is also constructed. This can be achieved, for example, by the arrangement of the outlets of the buffer volumes or by the shape of the first flow channel section. Furthermore, there is fluid communication between the buffer volumes in the form of flow channels that tangentially extend into the buffer volumes. The exchange of respiratory gas components occurs between buffer volumes via this flow channel, whereby respiratory gas components flow from one buffer volume to another. If this exchange is not required, the flow channel between the buffer volumes can be closed.

[0033] Furthermore, the present invention relates to a breathing or anesthesia machine incorporating a mixing device designed according to any of the foregoing embodiments. The respiratory gas components necessary for breathing are guided into the breathing or anesthesia machine via a central gas supply unit, a blower, and / or connected gas cylinders, and prepared according to the patient's needs. This includes, for example, setting a specific concentration of oxygen, which is guided into the mixing device along with air, so that the previously set oxygen concentration is achieved in the respiratory gas flow ultimately formed at the outlet of the mixing device. The mixing device mixes the respiratory gas components (e.g., oxygen and air) and achieves precise determination of the concentration of the respiratory gas components in the respiratory gas flow flowing out of the mixing device via the outlet, because the different respiratory gas components are approximately uniformly distributed across the flow cross-section. Here, the respiratory gas component flow (e.g., air, oxygen, and / or anesthetic gas) is guided into a first flow channel section via the inlet of the mixing device. It is conceivable that the mixing device has more than two inlets and therefore can mix more than two respiratory gas components, such as three or more. In the first flow channel section, the respiratory gas components undergo acceleration on their path to the transition to the second flow channel section, achieved through at least a progressively decreasing cross-section of the first flow channel section. This acceleration results in an increase in flow impulse and, together with the directional introduction of the respiratory gas components into the second flow channel section, helps to create vortices. Here, the respiratory gas component flow is preferably tangentially guided into the second flow channel section. The second flow channel section is arranged at an angle relative to the first flow channel section, such that the introduced respiratory gas component flow impinges on the inner wall region of the second flow channel section, which is at least partially opposite in the flow direction to the transition from the first to the second flow channel section (i.e., the outlet of the first flow channel section). This deflects the respiratory gas component flow and places it in a rotational motion about the longitudinal central axis of the second flow channel section, thus creating vortices. The vortices flow at least progressively spirally toward the outlet of the mixing device. The advantageously mixed respiratory gas flow exits the mixing device via the outlet and flows, for example, along an oxygen sensor used to determine oxygen concentration, before the mixed respiratory gas flow is supplied to the patient. Excellent mixing of the respiratory gas components in the respiratory gas stream can, for example, avoid false alarms caused by concentration gradients present in the respiratory gas stream and the resulting local concentration peaks. Furthermore, in the absence of such concentration peaks caused by insufficient mixing, the measured respiratory gas concentration simplifies the adjustment of the concentration ratio of the respiratory gas components, as there is no need to average and / or filter the concentration values ​​in this case.

[0034] Furthermore, the present invention relates to a method for manufacturing such a hybrid device, wherein at least one manufacturing step is part of either an injection molding method or a 3D printing method. Injection molding is advantageous when manufacturing a large number of hybrid devices. 3D printing is advantageous for manufacturing as quickly as possible. The hybrid device according to the invention is designed to enable both manufacturing methods to be implemented with minimal cost. Attached Figure Description

[0035] Further features, objects, and effects of the present invention will become apparent from the description and drawings. Embodiments of the invention are described, but the general inventive concept is not limited.

[0036] In the attached image: Figure 1 A schematic transparent view showing a mixing device with a streamline diagram of breathing gas flow; Figure 2 : A schematic cross-section of a flow channel section of a mixing device with a streamline diagram of breathing gas flow is shown; Figure 3 A schematic diagram of a preferred embodiment of a mixing device with a buffer volume is shown; and Figure 4 : A schematic diagram of a preferred embodiment of a mixing device with mixing elements is shown.

[0037] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Here, the same components are correspondingly provided with the same reference numerals in various figures. Detailed Implementation

[0038] exist Figure 1 A preferred embodiment is depicted in the schematic diagram of the mixing device 1, wherein the housing of the mixing device 1 is transparently shown, and the streamlines 13a, 13b, 13c, 14a, 14b, 14c of the flowing breathing gas are additionally shown. Three streamlines 13a, 13b, 13c of the first breathing gas component flow and three streamlines 14a, 14b, 14c of the second breathing gas component flow are exemplarily shown here, wherein the streamlines of the two breathing gas component flows are mixed into a breathing gas flow, as described below. The mixing device 1 includes a first inlet 2 and a second inlet 3 for introducing the two breathing gas components, a first flow channel section 4, a second flow channel section 5, and a transition section 6 from the first to the second flow channel sections 4, 5. Furthermore, the mixing device 1 also has an outlet 7 for discharging the mixed breathing gas.

[0039] exist Figure 1In one embodiment, the breathing gas components air and oxygen are mixed. Air is introduced into the first flow channel section 4 through a first inlet 2 and oxygen through a second inlet 3. The design of the first inlet 2 and the second inlet 3 causes the breathing gas components of air and oxygen to extend substantially side-by-side in the first flow channel section 4, forming a stratified flow 11 with regions in which the breathing gas components are adjacent to each other. The cross-section of the first flow channel section 4 decreases downstream to the transition section 6, thereby accelerating the stratified flow. The accelerated stratified flow 11 then flows tangentially into the second flow channel section 5. Here, the stratified flow is introduced into the second flow channel section 5 through the reduction in the cross-section of the first flow channel section 4, causing it to initially extend primarily along the first inner wall region 9. The stratified flow 11 then impacts a second inner wall region 10 arranged approximately perpendicular to the flow direction of the stratified flow 11. This deflects the stratified flow 11 into a vortex 12, i.e., a flow extending circularly around an axis. The vortex 12 flows spirally toward the outlet 7 around the longitudinal central axis 8 of the second flow channel section 5, in which the breathing gas components air and oxygen are mixed within the vortex 12.

[0040] Figure 2 A schematic cross-sectional view of the flow channel section of the mixing device 1 is shown, including streamline diagrams of the breathing gas flows 21, 22. A side view of the mixing device is shown here, illustrating the flow path along the... Figure 1A top view of the direction of the longitudinal central axis 8 of the second flow channel section 5. Breathing gas components air and oxygen are guided into the first flow channel section 4 via the first inlet 2 and the second inlet 3, where a first breathing gas component flow 21 and a second breathing gas component flow 22 are constructed. The stratified breathing gas component flows 21, 22, having surface contact areas, flow in the direction of the arrow to the transition section 6 and from the first flow channel section 4 into the second flow channel section 5, where they undergo acceleration due to the reduction in the cross-section of the first flow channel section 4. Through this acceleration, the breathing gas component flows 21, 22 gain an increased flow impulse and are guided into the second flow channel section 5, which is inclined relative to the first flow channel section 4, causing the stratified breathing gas component flows 21, 22 to impact the inner wall region of the second flow channel section 5, be deflected, and ultimately construct a vortex 12 propagating towards the outlet 7. Within the vortex 12, the contact surfaces of adjacent breathing gas component streams 21, 22 are multiplied, allowing the different breathing gas components, air and oxygen, to mix in a particularly advantageous manner. This is due to the convective transport of the breathing gas components in the breathing gas component streams 21, 22 through the vortex 12. Through this convective transport, as a particularly strong transport mechanism, the breathing gas components are approximately uniformly distributed in the second flow channel section 5, thereby increasing the contact area of ​​the breathing gas component streams 21, 22 and enhancing the mixing of the breathing gas components through diffusion.

[0041] exist Figure 3 A schematic diagram of a preferred embodiment of the mixing device 30 according to the invention is depicted. For better illustration, a portion of the mixing device 30 is concealed, thereby revealing its internal structure. The mixing device 30 includes a first inlet 2 and a second inlet 3 for introducing two respiratory gas components, a first flow channel section 4, a second flow channel section 5, a transition section 6 from the first to the second flow channel sections 4 and 5, and an outlet 7 for discharging the mixed respiratory gas. Furthermore, the mixing device 30 includes a first buffer volume 31 subsequently connected to the first inlet 2 in the flow direction, a second buffer volume 32 subsequently connected to the second inlet in the flow direction, and a flow channel 34 between the buffer volumes 31 and 32. Additionally, a flow-guiding element 33 is integrated in the first flow channel section 4. This flow-guiding element 33 reduces the cross-section of the first flow channel section 4 and alters the extension direction of the first flow channel section 4 such that the respiratory gas components are tangentially guided from the first flow channel section 4 to the second flow channel section 5, creating vortices in the second flow channel section 5. In this vortex, different respiratory gas components are mixed and the mixed respiratory gas flows out of the mixing device 30 through outlet 7.

[0042] Figure 4A schematic diagram of another preferred embodiment of the mixing device 40 according to the present invention is shown, wherein the mixing device 40 is shown transparently for better illustration. The mixing device 40 also includes a first inlet 2 and a second inlet 3 for introducing two respiratory gas components, a first flow channel section 4, a second flow channel section 5, a transition section 6 from the first to the second flow channel sections 4, 5, and an outlet 7 for discharging the mixed respiratory gas. In this embodiment, a first mixing element 41 is integrated in the first flow channel section 4 and a second mixing element 42 is integrated in the second flow channel section. The first and second mixing elements 41, 42 are implemented as static mixers without moving parts. The first mixing element 41 causes additional mixing of the different respiratory gas components by making them as in Figure 2 The stratified flow 11, comprising the respiratory gas component flows 21, 22, is deflected in different directions, causing the respiratory gas component flows to intersect and thus providing distribution and mixing of the respiratory gas components in the first flow channel section 4. Similarly, additional mixing of the respiratory gas components is generated within the vortex 12 by the second mixing element 42 in the second flow channel section 5, as it does, for example, in… Figure 1 As shown in the diagram, the vortex 12 is guided through a network of multiple flow channels extending in different directions, thereby distributing and further mixing the respiratory gas components.

[0043] List of reference numerals 1. Mixing device 2 First Entrance 3 Second Entrance 4 First flow channel section 5 Second flow channel section 6. Transition Section 7 Exports 8. Longitudinal center axis 9. First Inner Wall Region 10 Second Inner Wall Region 11 Layered Flow 12 Vortex 13a, 13b, 13c Streamlines of the first respiratory gas component flow 14a, 14b, 14c Streamlines of the second respiratory gas component flow 21 Flow of the first respiratory gas components 22 Second respiratory gas component flow 30 Preferred embodiments of the mixing device 31 First Buffer Volume 32 Second Buffer Volume 33. Components that guide flow 34. Flow channels between buffer volumes 40 Another preferred embodiment of the mixing device 41 First Hybrid Element 42 Second hybrid element.

Claims

1. Mixing device (1) for a breathing or anesthesia machine for mixing at least two breathing gas components, with a flow channel, which has a first flow channel section (4) with at least two inlets (2, 3) for introducing breathing gas components and a second flow channel section (5) with an outlet (7) for conducting a breathing gas flow with mixed breathing gas components, characterized in that The cross section of the first flow channel section (4) decreases at least section-wise in the direction of a transition (6) from the first flow channel section (4) into the second flow channel section (5), the first flow channel section (4) and the second flow channel section (5) being inclined to each other at least in the region of the transition (6) and the first flow channel section (4) opening into the second flow channel section (5) in the region of the transition (6) in such a way that a vortex flow (12) of the breathing gas flow around a longitudinal centre axis (8) is configured at least section-wise in the second flow channel section (5) which flows at least section-wise spirally in the direction of the outlet (7).

2. The mixing device (1) according to claim 1, characterized in that The first flow channel section (4) and the second flow channel section (5) are arranged approximately perpendicularly to each other in the region of the transition (6).

3. Mixing device (1) according to claim 1 or 2, characterized in that The first flow channel section (4) and / or the second flow channel section (5) has / have at least section-wise a rectangular cross section.

4. Mixing device (1) according to claim 1 or 2, characterized in that The first flow channel section (4) and / or the second flow channel section (5) is / are configured at least section-wise in the form of a cylinder, a truncated cone or a truncated pyramid.

5. Mixing device (1) according to any one of the preceding claims, characterized in that The at least two inlets (2, 3) have an approximately circular cross section.

6. Mixing device (1) according to any one of the preceding claims, characterized in that The cross section of the first flow channel section (4) decreases by more than 50% up to the transition (6) into the second flow channel section (5).

7. Mixing device (1) according to any one of the preceding claims, characterized in that The first flow channel section (4) and / or the second flow channel section (5) comprises a mixing element (41, 42) for mixing the breathing gas components.

8. Mixing device (1) according to any one of the preceding claims, characterized in that The at least two inlets (2, 3) are arranged approximately side by side to each other and thereby produce a stratified flow (11) of the breathing gas components in the first flow channel section (4).

9. Mixing device (1) according to any one of the preceding claims, characterized in that The at least two inlets (2, 3) of the first flow channel section (4) are followed in each case by a buffer volume (31, 32), the cross section of the buffer volumes (31, 32) being approximately circular and there being a fluid connection between the buffer volumes (31, 32) in the form of a flow channel (34) which opens tangentially into the buffer volumes (31, 32).

10. Breathing or anaesthesia machine with a mixing device (1) according to at least one of the preceding claims.

11. A method for manufacturing a mixing device (1) according to any one of claims 1 to 9, wherein, At least one manufacturing step is part of an injection moulding method or a 3D printing method. At least one manufacturing step is part of an injection moulding method or a 3D printing method.

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