WO2025021260A1 - Mixing device, respirator or anaesthesia machine comprising a mixing device, and method for producing a mixing device - Google Patents

Abstract

The present invention relates to a mixing device (1) for a respirator or anaesthesia machine for mixing at least two respiratory-gas components, comprising a flow channel which has a first flow-channel portion (4) with at least two inlets (2, 3) for introducing the respiratory-gas components and a second flow-channel portion (5) with an outlet (7) for discharging a respiratory-gas stream comprising the respiratory-gas components. The mixing device (1) is distinguished in that a cross section of the first flow-channel portion (4) at least partially decreases downstream towards a transition (6) from the first to the second flow-channel portion (4, 5), the first and the second flow-channel portion (4, 5) are inclined relative to one another and, in the region of the transition (6), the first flow-channel portion (4) opens out into the second flow-channel portion (5) in such a way that a turbulent flow (12) of the respiratory-gas stream is at least partially formed around a longitudinal centre axis (8) in the second flow-channel portion (5) and flows at least partially in a spiral towards the outlet (7). The invention also relates to a respirator or anaesthesia machine comprising such a mixing device (1) and to a method for producing such a mixing device (1).

Description

Mixing device, ventilator or anesthesia device with a mixing device and method for producing a mixing device

The present invention relates to a mixing device for a ventilator or anesthesia device, a ventilator or anesthesia device with a mixing device for mixing at least two respiratory gas components and a method for producing the mixing device.

Ventilating a patient using ventilators or anesthesia machines involves supplying the patient with breathing gas. The breathing gas is usually a mixture of two or more breathing gas components. The breathing gas components most commonly used in practice are air and oxygen. The breathing gas components can be obtained from different sources, for example via a central gas supply to which the ventilator or anesthesia machine is connected at the installation site, via a gas cylinder filled with the respective breathing gas component, and/or via the suction of air from the environment by the ventilator or anesthesia machine itself, the so-called blower technology.

The supplied breathing gas components are mixed in the ventilator or anesthesia device in order to achieve at least a nearly even distribution of the breathing gas components. This is necessary above all to ensure correct monitoring of the breathing gas afterwards, while it is important for the safety of the patient and for successful therapy that the breathing gas concentration set on the ventilator or anesthesia device is present in the breathing gas flow. Deviations from the set ratio of the breathing gas components arise from tolerances in the concentration when supplying breathing gas components, especially when using a gas cylinder, and from tolerances in valves. regarding the flow rate and the measurements of the sensors. The sensors used to monitor 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 measuring point. Local concentration differences can therefore lead to incorrect measurements and trigger false alarms if the measured gas concentration is too low, for example. A mixed breathing gas is therefore desired in which the concentration differences of the respective breathing gas component are as low as possible.

To produce a mixed breathing gas, mixing devices within a ventilator or anesthesia device are known that have a hollow body or a volume into which the breathing gas components are fed for mixing. The size of such a mixing tank is selected such that the residence time of the breathing gas flow is at least long enough for almost uniform concentrations of the breathing gas components to be established through diffusion. The long residence time means that changes in the concentration of a breathing gas component in the ventilator or anesthesia device only occur slowly, since the mixing tank must be filled as an additional volume of breathing gas and flow through it. This limits the dynamic range of a ventilator or anesthesia device with such mixing volumes during ventilation.

Motor-driven mixers are also known from the state of the art, whereby, for example, the mixing of the breathing gas components is achieved by installing a motor-driven stirrer in the ventilator or anesthesia device and operating it. The disadvantage of this solution is the associated high costs for the necessary components as well as their operation and maintenance.

Both of the above-mentioned solutions require a comparatively large amount of space in the ventilator or anesthesia machine. This disadvantageously increases the size of such a device. Furthermore, static flow mixers are known from the prior art. US 2016082220 A1 shows a system for respiratory therapy with a static flow mixer. The described static flow mixer is configured such that it can mix several respiratory gas components and comprises an inlet and an outlet as well as a first baffle between the inlet and the outlet. Furthermore, the static flow mixer comprises a constriction arranged between a downstream edge of the first baffle and a nearest downstream surface, wherein a length of the constriction is less than a height of the first baffle. This technical solution is intended to evenly mix respiratory gas components fed to the static flow mixer. Other static flow mixers are known from 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 channel, which has a negative impact on the dynamic properties of a ventilation or anesthesia device. Furthermore, these static flow mixers require a lot of installation space and have a complex geometry, which is why their manufacture is very complex.

Based on the solutions known from the prior art and the problems described above, the invention is based on the object of creating a device which produces a mixed breathing gas consisting of at least two breathing gas components for use in a ventilator or anesthesia device in a simple and reliable manner. The dynamic properties of the ventilator or anesthesia device for ventilation should be influenced as little as possible, in particular a change in the concentration of one of the breathing gas components on the ventilator or anesthesia device should be able to be brought about as quickly as possible and with as little pressure drop as possible.

The above object is achieved by a mixing device with the features of claim 1 and a ventilation or anesthesia device according to claim 10, which has a mixing device. Furthermore, the The object is achieved by a method for producing a mixing device with the features of claim 11. Further details of the invention emerge from the subclaims, the description and the drawings. Features and details that are described in connection with the device according to the invention are of course also considered to be disclosed in connection with the ventilation or anesthesia device according to the invention, which has such a mixing device, and the method according to the invention, so that with regard to the disclosure of the individual aspects of the invention, reference is always made or can be made to each other.

The mixing device according to the invention for a ventilation or anesthesia device for mixing at least two respiratory gas components comprises a flow channel which has a first flow channel section with at least two inlets, each of which is suitable for introducing the respiratory gas components, i.e. air and/or gas flows, and a second flow channel section with an outlet for discharging a respiratory gas flow which has the mixed respiratory gas components. The mixing device is characterized in that a cross section of the first flow channel section decreases at least in sections downstream in the direction of a transition from the first to the second flow channel section, the first and second flow channel sections are inclined towards one another at least in the region of the transition, and the first flow channel section opens into the second flow channel section in the region of the transition in such a way that a vortex flow of the respiratory gas flow is at least partially formed around a longitudinal center axis of the second flow channel section in the second flow channel section, which vortex flow flows at least in sections in a spiral shape in the direction of the outlet.

The core of the invention is to mix the at least two respiratory gas components, which are at least part of an air and/or gas flow, so that a respiratory gas flow with almost evenly distributed respiratory gas components is created and thus at least almost no Differences in the concentrations of the individual respiratory gas components exist across the flow cross-section. This is achieved by the two sections of the flow channel according to the invention, which are designed and arranged in such a way that a vortex flow with the respiratory gas components forms in the second flow channel section, which spreads out at least in sections in the direction of flow in the form of a flow spiral or flow roller. The air, gas and/or gas mixture flowing in the area of the second flow channel section is thus at least partially set in a movement that rotates about a longitudinal center axis of the second flow channel section and is simultaneously directed towards the outlet of the flow channel. This results in effective mixing of the respiratory gas components.

Examples of breathing gas components are air and oxygen. However, other gases, gas mixtures or gas-air mixtures that are used for ventilation, for anesthesia and/or at least temporary sedation of a patient in a ventilator and/or anesthesia device are also conceivable.

A vortex flow, sometimes also called a vortex roller, describes a rotating flow movement of a fluid around an axis of rotation, with the fluid moving downstream in the longitudinal direction of the axis of rotation at least almost parallel to or inclined to it. It is created, for example, by a targeted steering of the flow and/or by the application of an external force.

The transport of a respiratory gas component in a respiratory gas stream can generally be described by the following transport equation:

The first term — (pY describes the temporal change, the second term V ■ (pYjU) the convective transport, the third term V ■ (pDjjVYj) the diffusive transport and the last term Wj sources or sinks. The diffusive The transport mechanism is comparatively weak and is hampered by long diffusion distances and small transport coefficients. For example, in a mixing tank, diffusive transport predominantly takes place. Therefore, a comparatively long residence time of the breathing gas components in the mixing tank is required in order to achieve the desired mixing of different breathing gas components and leads to the disadvantages described above.

In contrast to the diffusive transport mechanism, convective transport is considered to be a very strong transport mechanism. According to the invention, this transport mechanism is used advantageously by deliberately generating a vortex flow to mix different respiratory gas components.

The various breathing gas components, which can be air, a gas or a gas mixture, are introduced into the mixing device via at least two inlets. More than two inlets are conceivable, especially if more than two breathing gas components are to be mixed together.

The inlets are arranged on the flow channel in such a way that the respiratory gas component flows run spatially next to one another within the first flow channel section and a layered flow of the respiratory gas components is formed. In the area of the contact surfaces, where the respiratory gas component flows border one another, the different respiratory gas components are already at least partially mixed by diffusion processes. The layered flow of the respiratory gas components flows in the direction of the transition from the first to the second flow channel section.

It is further conceivable that the inlets are arranged on the flow channel in such a way that the respiratory gas component flows at least partially intersect within the first flow channel section and/or the individual respiratory gas component flows are diverted. The preferably layered flow, i.e. the flow in which different respiratory gas component flows are arranged in layers, is accelerated by the decreasing cross-section of the first flow channel section and is guided with a higher flow impulse in the area of the transition, for example tangentially into the second flow channel section. Tangential introduction in this case means that the layered flow is only introduced in a partial area of the inner wall of the second flow channel section, i.e. not centrally or across the entire cross-section of the second flow channel section. After being introduced into the second flow channel section, the layered flow initially flows only along a partial area of the inner wall of the second flow channel section, while other areas of the inner wall have little or no contact with the layered flow immediately or during the formation of the vortex flow. Essentially, the layered flow touches the inner wall of the second flow channel section when flowing in and has an asymmetrical distribution in the second flow channel section in the area of the transition. The reduction in the cross-section of the first flow channel section can preferably be achieved by reducing the circumference 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 part of the layered flow and guides it through a smaller flow channel cross-section than that of the first flow channel section. It is also conceivable that this additional element guides the layered flow into the second flow channel section in such a way that, as described above, a vortex flow is formed.

The acceleration and the tangential introduction of the layered flow, i.e. the directed introduction of the layered flow along a partial area of the inner wall of the second flow channel section, and the inclination between the first and second flow channel sections lead according to the invention to the formation of a Vortex flow within the second flow channel section. The inclination of the second flow channel section to the first flow channel section means that their longitudinal center axes are inclined to one another at an angle other than zero. As a result, the layered flow running along a partial area of the inner wall of the second flow channel section encounters at least one inner wall area of the second flow channel section that is inclined to this partial area, is at least partially deflected, and a vortex flow is formed. It is also conceivable that the layered flow is introduced into the second flow channel section as an alternative or in addition to the preferred tangential introduction in such a way that it initially does not run or only partially runs along a partial area of the inner wall or along several areas of the inner wall. It is essential that the layered flow, as it continues along the second flow channel section, at least partially meets another inner wall area that is at least partially inclined to the direction of flow, is deflected, and at least partially forms a vortex flow. For example, by directing the accelerated, stratified flow centrally at the transition from the first to the second flow channel section and, due to the inclination of the second flow channel section to the first flow channel section, subsequently hitting one of the inner wall regions of the second flow channel section.

According to the invention, the layered flow of the respiratory gas components of the first flow channel section in the first flow section becomes at least partially a vortex flow in the second flow channel section, whereby several of these layers of the respiratory gas components are placed next to one another by the rotational movement of the vortex flow, thus multiplying the layers of different respiratory gas components arranged next to one another. For example, the initially two layers of two different respiratory gas components of the layered flow become four, six or more layers of two respiratory gas components in the cross-section of the vortex flow. The respiratory gas components are thus transported by convective transport by means of the Vortex flow is distributed in the second flow channel section and the contact area at which the various respiratory gas component flows adjoin one another is increased, whereby an increased mixing of the respiratory gas components takes place through diffusion. The vortex flow flows at least in sections in a spiral shape in the direction of the outlet, at which a mixed respiratory gas flow has been formed by convective transport of the various respiratory gas components in an advantageous manner with a small installation size of the mixing device and little influence on the dynamic properties of a ventilation or anesthesia device.

Various respiratory gas components can be mixed in an advantageous manner using such a mixing device. The required installation space is greatly reduced compared to a conventional mixing tank of a ventilator or anesthesia device, allowing a small installation size and a larger dynamic range of a ventilator or anesthesia device. Setting changes on a ventilator or anesthesia device, such as a change in the concentration of one of the respiratory gas components, can thus be implemented quickly and with little pressure drop. Furthermore, the structure is easy to manufacture compared to a static mixer. In contrast to motor-driven mixers, no active drive and the associated more complex structure and increased energy consumption are required, and the vortex flow is generated solely by the simpler structure of the mixing device according to the invention and the existing flow. The mixing device is therefore easy to manufacture and the manufacturing costs are kept within an economically reasonable range.

In a preferred embodiment, the first flow channel section and the second flow channel section are arranged almost perpendicular to each other in the transition region. The inclination of the flow channel sections to each other serves to form a vortex flow in the second flow channel section. An inclination of the first and second flow channel sections by almost 90° is particularly advantageous for the formation of the vortex flow. The longitudinal center axes are almost perpendicular to each other and the layered Due to the inclination, the flow of the first flow channel section hits an edge area of the second flow channel section in the direction of flow, is thereby deflected and a vortex flow is formed. The vortex flow is particularly pronounced when the first flow channel section is arranged almost vertically to the second flow channel section, so that the mixing of the various breathing gas components is also improved. Furthermore, a particularly stable vortex flow is formed as the flow continues through the second flow channel section, with the flow direction running around the longitudinal center axis of the second flow channel section, the longitudinal center axis thus essentially forming the center of the vortex flow, and thus flowing in the direction of the outlet in a manner adapted to the geometry of the second flow channel section.

A further advantage of the almost vertical arrangement of the first and second flow channel sections is a more compact design and thus a space saving when installed in a ventilation or anesthesia device.

According to a particularly preferred embodiment of the mixing device, the first flow channel section and/or the second flow channel section have a rectangular cross-section at least in sections. It is conceivable that the cross-section has a rectangular shape or, particularly preferably, a square shape. The advantage of this is the improved use of the installation space when installing the mixing device in a ventilation or anesthesia device. An at least partially rectangular cross-section of the second flow channel section is particularly advantageous, with secondary vortices forming due to the vortex flow in the four corners within the second flow channel section, which improve the mixing of the various respiratory gas components.

In a preferred embodiment of the mixing device, the first flow channel section and/or the second flow channel section is at least partially designed in the form of a cylinder, a truncated cone or a truncated pyramid. A substantially circular The cross-section of the first and/or second flow channel section has the advantage that, for example, breathing gas hoses can be attached more easily to the inlets and/or outlet of the mixing device. An at least partially circular cross-section of the second flow channel section is particularly advantageous, whereby a particularly stable vortex flow is formed, which flows at least in sections in a spiral shape and guided by the second flow channel section in the direction of the outlet.

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

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. The cross section is preferably reduced evenly from the area of the inlets to the transition to the second flow channel section. It is also conceivable that the reduction in the cross section only affects a partial area of the first flow channel section. For example, the cross section is reduced by more than 50% from the middle of the first flow channel section to the transition to the second flow channel section. It is also conceivable that the reduction in the cross section is only formed shortly before the transition to the second flow channel section.

The particular advantage of reducing the cross-section by more than 50% is that the resulting flow impulse of the layered flow is strong enough to promote the formation of the vortex flow in the second flow channel section. In particular for typical volume flows of a ventilation or anesthesia device in the range of 1 l/min to 180 l/min, a vortex flow can thus be advantageously generated.

According to a preferred embodiment of the mixing device, the first flow channel section and/or the second flow channel section comprise a mixing element for mixing the respiratory gas components. Mixing elements can be, for example, static mixers or similar geometries that are integrated into the first and/or second flow channel section. The layered flow of the first flow channel section and/or the vortex flow of the second flow channel section encounters a mixing element and additional mixing of the respiratory gas components takes place. In an advantageous manner, improved mixing of the respiratory gas components at the outlet of the mixing device is achieved by a suitable mixing element without enlarging the mixing device and having to provide additional installation space when installing it in a ventilation or anesthesia device. The external dimensions of the mixing element should correspond to or be smaller than the internal circumference of the first or second flow channel section. Furthermore, the mixing element should have as little flow resistance as possible. It is conceivable to integrate one or more mixing elements into the first and/or second flow channel section. It is also conceivable that the mixing elements within the mixing device have a different structure.

In a preferred embodiment of the mixing device, the at least two inlets are arranged essentially next to one another, resulting in a layered flow of the respiratory gas components in the first flow channel section. Such an arrangement of the inlets results in a special layered flow in which the respiratory gas component flows essentially run next to one another and their flow speed remains almost the same, i.e. the flow is not weakened. This advantageously promotes the formation of a vortex roller in the second flow channel section.

According to a preferred embodiment of the mixing device, a buffer volume is arranged downstream of the at least two inlets of the first flow channel section and a cross section of the buffer volume is essentially circular. The buffer volumes are preferably cylindrical and the respiratory gas component streams preferably flow from the inlets directly into the buffer volumes. The cross sections of the buffer volumes preferably correspond to the cross-section of the respective inlet, so that the respective buffer volume can be filled as quickly as possible with the inflowing respiratory gas component. The buffer volumes preferably each have a size in the range of 25 to 35 ml, particularly preferably 30 ml. The respiratory gas component flows are introduced via the inlets into a buffer volume, which is filled with the corresponding respiratory gas component. When the respiratory gas component flows exit the buffer volumes within the first flow channel section, a layered flow is also formed. 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 a flow channel that opens tangentially into the buffer volumes. An exchange of the respective respiratory gas components takes place between the buffer volumes through the flow channel, with a respiratory gas component flow flowing via the flow channel from one buffer volume to the other. It is conceivable to close the flow channel between the buffer volumes if an exchange across it is not necessary.

The invention further relates to a ventilator or anesthesia device with a mixing device which is designed according to one of the previously described embodiments. The respiratory gas components required for ventilation are fed into the ventilator or anesthesia device, for example via a central gas supply, a blower and/or a connected gas bottle, and are prepared according to the needs of a patient. This includes setting a certain concentration of oxygen, which is fed into the mixing device with air, for example, so that the previously set oxygen concentration is achieved in the respiratory gas stream finally formed at the outlet of the mixing device. The mixing device mixes the respiratory gas components, for example oxygen and air, and enables an accurate determination of the concentration of a respiratory gas component of the respiratory gas stream of the mixing device flowing out via the outlet, since the different respiratory gas components are distributed almost evenly over the flow cross-section. The respiratory gas component flows, for example air, oxygen and/or an anesthetic gas, are guided into the first flow channel section via the inlets of the mixing device. It is conceivable that the mixing device has more than two inlets and can thus mix more than two respiratory gas components, for example three respiratory gas components or more. The respiratory gas component flows in the first flow channel section experience an acceleration on the way to the transition to the second flow channel section, which is achieved by at least partially reducing the cross-section of the first flow channel section. The acceleration causes an increase in the flow impulse and, together with a directed introduction of the respiratory gas component flows into the second flow channel section, contributes to the formation of a vortex flow. The respiratory gas component flows are preferably guided tangentially into the second flow channel section. The second flow channel section is arranged at an angle to the first flow channel section, so that the introduced respiratory gas component flows hit an inner wall area of the second flow channel section that is at least partially opposite the transition from the first to the second flow channel section, i.e. an outlet of the first flow channel section, in the direction of flow. As a result, the respiratory gas component flows are diverted and set in a rotating movement about a longitudinal center axis of the second flow channel section and a vortex flow is formed. The vortex flow flows at least in sections in a spiral shape in the direction of the outlet of the mixing device. The advantageously mixed respiratory gas flow leaves the mixing device via the outlet and flows, for example, along an oxygen sensor to determine the oxygen concentration before the mixed respiratory gas flow is supplied to the patient. Due to the particularly good mixing of the respiratory gas components in the respiratory gas flow, false alarms due to concentration gradients present in the respiratory gas flow and local concentration peaks in the respiratory gas flow caused by this can be avoided. Furthermore, a measured respiratory gas concentration without such concentration peaks due to insufficient mixing allows a regulation of the concentration ratio of the respiratory gas components, since the concentration values in this case do not have to be averaged and/or filtered.

The invention further relates to a method for producing such a mixing device, wherein at least one production step is part of an injection molding process or 3D printing process. The injection molding process is advantageous for producing a large number of mixing devices. The 3D printing process is advantageous for producing as quickly as possible. The mixing device according to the invention is designed in such a way that both production processes can be implemented with little effort.

Further features, objects and effects of the invention emerge from the description and the accompanying figures. Embodiments of the invention are described without restricting the general inventive concept.

In the figures shows:

Fig. 1 : a schematic, transparent representation of a mixing device with streamline representation of the respiratory gas flow,

Fig. 2: a schematic representation of a section of the flow channel sections of a mixing device with streamline representation of the respiratory gas flow,

Fig. 3: a schematic representation of a preferred embodiment of a mixing device with buffer volume, and Fig. 4: a schematic representation of a preferred embodiment of a mixing device with mixing elements.

Embodiments of the invention are described in detail below with reference to the accompanying figures. Similar components in several figures are each provided with the same reference numerals.

In Fig. 1, a preferred embodiment is shown using a schematic representation of a mixing device 1, wherein the housing of the mixing device 1 is shown transparently and the streamlines 13a, 13b, 13c, 14a, 14b, 14c of the flowing respiratory gases are also shown. Three exemplary streamlines 13a, 13b, 13c of a first respiratory gas component stream and three streamlines 14a, 14b, 14c of a second respiratory gas component stream are shown, wherein the streamlines of the two respiratory gas component streams mix to form one respiratory gas stream, as described below. The mixing device 1 comprises 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 and a transition 6 from the first to the second flow channel section 4, 5. Furthermore, the mixing device 1 has an outlet 7 for discharging the mixed respiratory gas.

In the embodiment in Fig. 1, the respiratory gas components air and oxygen are mixed. Air is introduced into the first flow channel section 4 through the first inlet 2 and oxygen through the second inlet 3. The design of the first inlet 2 and the second inlet 3 means that the respiratory gas component flows of air and oxygen run essentially next to each other in the first flow channel section 4 and a layered flow 11 is formed with an area in which the respiratory gas component flows adjoin one another. The cross section of the first flow channel section 4 decreases downstream to the transition 6, whereby the layered flow is accelerated. The accelerated, layered flow 11 then flows tangentially into the second flow channel section 5. the layered flow is introduced into the second flow channel section 5 by reducing the cross-section of the first flow channel section 4 in such a way that it initially runs mainly along a first inner wall region 9. The layered flow 11 then encounters a second inner wall region 10, which is arranged almost perpendicular to the flow direction of the layered flow 11. As a result, the layered flow 11 is deflected in such a way that a vortex flow 12 is formed, i.e. a flow that runs in a circle around an axis. The vortex flow 12 flows spirally around a longitudinal center axis 8 of the second flow channel section 5 in the direction of the outlet 7, with the respiratory gas components air and oxygen mixing within the vortex flow 12.

Fig. 2 shows a schematic representation of a section of the flow channel sections of the mixing device 1 including a streamline representation of the respiratory gas flow 21, 22. A side view of the mixing device is shown, which shows a plan view in the direction of the longitudinal center axis 8 of the second flow channel section 5 according to Fig. 1. The respiratory gas components air and oxygen are guided via the first inlet 2 and the second inlet 3 into the first flow channel section 4, in which a first respiratory gas component flow 21 and a second respiratory gas component flow 22 are formed. The layered respiratory gas component flows 21, 22, which have a flat contact area, flow in the direction of the arrow to the transition 6 and from the first to the second flow channel section 4, 5, wherein they experience acceleration due to a reduction in the cross section of the first flow channel section 4. Due to this acceleration, the respiratory gas component streams 21, 22 receive an increased flow impulse and are guided into the second flow channel section 5, which is inclined to the first flow channel section 4, so that the layered respiratory gas component streams 21, 22 meet an inner wall region of the second flow channel section 5, are deflected and finally a vortex flow 12, which propagates in the direction of the outlet 7, forms. Within the vortex flow 12, the adjacent contact surfaces of the layered respiratory gas component flows 21, 22 multiply, with the various respiratory gas components air and oxygen mixing in a particularly advantageous manner. The reason for this is the convective transport of the respiratory gas components of the respiratory gas component flows 21, 22 caused by the vortex flow 12. As a result of this convective transport, as a particularly strong transport mechanism, the respiratory gas components are distributed almost evenly in the second flow channel section 5, whereby the contact area of the respiratory gas component flows 21, 22 is increased and an increased mixing of the respiratory gas components takes place through diffusion.

Fig. 3 shows a schematic representation of a preferred embodiment of a mixing device 30 according to the invention. For better clarity, part of the mixing device 30 has been hidden so that the internal structure can be seen. The mixing device 30 comprises 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 6 from the first to the second flow channel section 4, 5 and an outlet 7 for discharging the mixed respiratory gas. The mixing device 30 also comprises a first buffer volume 31, which is connected downstream of the first inlet 2 in the flow direction, and a second buffer volume 32, which is connected downstream of the second inlet in the flow direction and a flow channel 34 between the buffer volumes 31, 32. In addition, 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 changes the direction of the first flow channel section 4 in such a way that respiratory gas component flows from the first flow channel section 4 are guided tangentially into the second flow channel section 5 and a vortex flow is formed in the second flow channel section 5. In this vortex flow Different breathing gas components mix and a mixed breathing gas stream leaves the mixing device 30 via the outlet 7.

Fig. 4 shows a schematic representation of another preferred embodiment of a mixing device 40 designed according to the invention, wherein the mixing device 40 is shown transparent for better clarity. The mixing device 40 also comprises 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 6 from the first to the second flow channel section 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 designed in the form of static mixers that have no moving parts. The first mixing element 41 causes an additional mixing of the various respiratory gas components by diverting the layered flow 11, which contains the respiratory gas component flows 21, 22, as shown in Fig. 2, in different directions, so that the respiratory gas component flows cross and thus a distribution and mixing of the respiratory gas components is already created in the first flow channel section 4. In a similar way, an additional mixing of the respiratory gas components within the vortex flow 12, as shown for example in Fig. 1, is created by a second mixing element 42 in the second flow channel section 5. There, the vortex flow 12 is guided through a network of several flow channels that run in different directions, whereby the respiratory gas components are also distributed and additional mixing occurs.

1 mixing device

2 first entry

3 second inlet

4 first flow channel section

5 second flow channel section

6 transition

7 outlet

8 longitudinal center axis

9 first interior wall area

10 second interior wall area

11 stratified flow

12 vortex roller

13a, 13b, 13c Streamlines of a first respiratory gas component flow

14a, 14b, 14c Streamlines of a second respiratory gas component flow

21 first respiratory gas component flow

22 second respiratory gas component flow

30 preferred embodiment of a mixing device

31 first buffer volume

32 second buffer volume

33 flow-guiding element

34 Flow channel between the buffer volumes

40 further preferred embodiment of a mixing device

41 first mixing element

42 second mixing element

Claims

patent claims 1 . Mixing device (1) for a ventilation or anesthesia device for mixing at least two respiratory gas components with a flow channel which has a first flow channel section (4) with at least two inlets (2, 3) for introducing the respiratory gas components and a second flow channel section (5) with an outlet (7) for discharging a respiratory gas flow which has the mixed respiratory gas components, characterized in that a cross section of the first flow channel section (4) decreases at least in sections downstream in the direction of a transition (6) from the first to the second flow channel section (4, 5), the first and the second flow channel sections (4, 5) are inclined towards one another at least in the region of the transition (6), 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 a vortex flow (12) of the respiratory gas flow around a longitudinal center axis (8) in the second Flow channel section (5) which flows at least partially in a spiral manner in the direction of the outlet (7). 2. 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 almost perpendicular 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) have a rectangular cross-section at least in sections. 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 at least partially designed in the form of a cylinder, a truncated cone or a truncated pyramid. 5. Mixing device (1) according to one of the preceding claims, characterized in that the at least two inlets (2, 3) have an almost circular cross-section. 6. Mixing device (1) according to one of the preceding claims, characterized in that the cross section of the first flow channel section (4) is reduced by more than 50% up to the transition (6) to the second flow channel section (5). 7. Mixing device (1) according to 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 one of the preceding claims, characterized in that the at least two inlets (2, 3) are arranged substantially next to one another, resulting in a layered flow (11) of the respiratory gas components in the first flow channel section (4). 9. Mixing device (1) according to one of the preceding claims, characterized in that a buffer volume (31, 32) is arranged downstream of the at least two inlets (2, 3) of the first flow channel section (4), a cross section of the buffer volumes (31, 32) is substantially circular and that there is fluid communication between the buffer volumes (31, 32) in the form of a flow channel (34) which opens tangentially into the buffer volumes (31, 32). 10. Ventilation or anesthesia device with a mixing device (1) according to at least one of the preceding claims. 11. Method for producing a mixing device (1) according to one of claims 1 to 9, wherein at least one manufacturing step is part of an injection molding process or 3D printing process.