Mixing apparatus, ventilator or anesthesia machine equipped with mixing apparatus, and method for manufacturing a mixing apparatus
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-07-25
- Publication Date
- 2026-08-14
Smart Images
Figure 2026527505000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a mixing device for a ventilator or anesthesia machine, a ventilator or anesthesia machine equipped with a mixing device for mixing at least two respiratory gas components, and a method for manufacturing the mixing device.
[0002] Patient respiration using a ventilator or anesthesia machine refers to the supply of respiratory gases to the patient. In this case, respiratory gases are usually a mixture of two or more respiratory gas components. In practice, the most frequently occurring respiratory gas components are air and oxygen. Respiratory gas components can be received from various gas sources, for example, through a central gas supply unit to which the ventilator or anesthesia machine is connected at the installation site, through gas cylinders filled with each respiratory gas component, and / or through the intake of ambient air by the ventilator or anesthesia machine itself, so-called blower technology.
[0003] The supplied respiratory gas components are mixed in the ventilator or anesthesia machine to achieve at least a nearly uniform distribution of the respiratory gas components. This is necessary, in particular, to ensure continued accurate monitoring of the respiratory gases, and on the other hand, it is important for patient safety and effective treatment that the respiratory gas concentrations set in the ventilator or anesthesia machine are present in the respiratory gas stream. Deviations from the set ratio of respiratory gas components can occur due to concentration errors during the supply of respiratory gas components, especially when using gas cylinders, if there are errors in the flow rate and valves related to sensor measurements. Sensors used to monitor the characteristics of respiratory gases typically only detect local gas characteristics, such as the concentration of each respiratory gas component at each measurement point. Therefore, local concentration differences can lead to mismeasurements and false alarms, for example, if the measured gas concentration is too low. In other words, a mixed respiratory gas in which the concentration differences of each respiratory gas component are as small as possible is desirable.
[0004] Mixing devices located inside ventilators or anesthesia machines are known for producing mixed respiratory gases, and these mixing devices have a hollow body or volume into which the respiratory gas components are introduced for mixing. The size of such a mixing tank is selected such that the residence time of the respiratory gas flow is short, and a nearly uniform concentration of the respiratory gas components is produced by diffusion. The long residence time assumes that the change in the concentration of the respiratory gas components in the ventilator or anesthesia machine occurs slowly, because the respiratory gas must be filled into the mixing tank as an additional volume and pass through this mixing tank. Thus, during respiration, the dynamic range of the ventilator or anesthesia machine is limited by such a mixing volume.
[0005] Furthermore, motor-driven mixers are known from the prior art, in which case, for example, a motor-driven agitator is incorporated into a ventilator or anesthesia machine, and the mixing of respiratory gas components is achieved by the operation of this agitator. The drawback of such solutions is that the necessary components and the costs associated with their operation and maintenance are high.
[0006] Both of the above solutions require a relatively large space in the ventilator or anesthesia machine. This unfortunately increases the structural size of such equipment.
[0007] Furthermore, static flow mixers are known from the prior art. U.S. Patent Application Publication No. 2016082220 describes a system for respiratory therapy comprising a static flow mixer. The static flow mixer described above is configured to be able to mix multiple respiratory gas components and includes an inlet and an outlet, and a first deflection metal sheet between the inlet and the outlet. Furthermore, this static flow mixer has a constriction located between the downstream edge of the first deflection metal sheet and the nearest downstream surface, the length of which the constriction is less than the height of the first deflection metal sheet. With this technical solution, the respiratory gas components supplied to the static flow mixer should be uniformly mixed. Another static flow mixer is known from European Patent No. 1312409 and European Patent No. 1426099. The problem with this static flow mixer is that it creates additional flow resistance in the breathing gas flow path, which unfavorably affects the dynamic characteristics of the ventilator or anesthesia machine. Furthermore, this static flow mixer requires a lot of structural space and has a complex geometric shape, making its manufacture very time-consuming.
[0008] Building upon known solutions from the prior art and the aforementioned problems, the fundamental objective of the present invention is to provide an apparatus for easily and reliably producing a mixed respiratory gas consisting of at least two respiratory gas components for use in a ventilator or anesthesia machine. In this case, it is desirable that the dynamic characteristics of the ventilator or anesthesia machine for respiration be affected as little as possible, and in particular, that the change in the concentration of one of the respiratory gas components in the ventilator or anesthesia machine be brought about as quickly as possible and with the smallest possible pressure drop.
[0009] The above problem is solved by a mixing device having the features of claim 1, and by a ventilator or anesthesia machine according to claim 10 having a mixing device. Furthermore, this problem is solved by a method for manufacturing a mixing device having the features of claim 11. Further details of the present invention are evident from the dependent claims, detailed description and drawings. In this case, features and details described in relation to the apparatus according to the present invention are of course considered disclosed in relation to a ventilator or anesthesia machine according to the present invention having such a type of mixing device, and by a method according to the present invention, so that the disclosures for individual embodiments of the present invention are always related to, or rather can be related to, each other.
[0010] A mixing device according to the present invention for a ventilator or anesthesia machine for mixing at least two respiratory gas components has a flow path including a first flow path section having at least two inlets suitable for introducing respiratory gas components, i.e., respiratory gas components from air and / or a gas stream, respectively, and a second flow path section having an outlet for discharging a respiratory gas stream having mixed respiratory gas components. The mixing device is characterized in that the cross section of the first flow path section is reduced in at least a predetermined portion downstream in the direction toward the transition from the first flow path section to the second flow path section, the first flow path section and the second flow path section are inclined toward each other at least in the region of the transition section, and the first flow path section opens to the second flow path section such that in the region of the transition section, a vortex of respiratory gas stream flows spirally in at least a predetermined portion toward the outlet, and a vortex of respiratory gas stream is formed at least partially within the second flow path section, centered on the longitudinal central axis of the second flow path section.
[0011] The core of the present invention is to mix at least two breathing gas components, which are at least a portion of the airflow and / or gasflow, thereby creating a breathing gas flow with substantially uniformly distributed breathing gas components, and consequently, having at least virtually no concentration difference of individual breathing gas components across the flow cross-section. This is achieved by two divisions of the flow path according to the present invention, which are configured and arranged such that a vortex flow containing breathing gas components, which spreads in the flow direction in the form of a flow spiral or flow roll in at least a predetermined portion, is formed in the second flow path. Thus, the airflow, gasflow and / or gas mixture flowing in the region of the second flow path are at least partially rotated about the longitudinal central axis of the second flow path and simultaneously directed toward the outlet of the flow path. In this case, effective mixing of breathing gas components is achieved.
[0012] Examples of respiratory gas components are air and oxygen. However, other gases, gas mixtures, or gas-air mixtures may also be used in ventilators and / or anesthesia machines to administer anesthesia and / or to sedate the patient, at least temporarily, during mechanical ventilation.
[0013] A vortex, sometimes called a vortex roll, refers to the rotational flow motion of a fluid around a rotation axis, in which case the fluid travels at least nearly parallel to, or at an angle to, the longitudinal direction of the rotation axis downstream. This can be caused, for example, by deflecting the flow as intended and / or by applying an external force.
[0014] However, the respiratory gas component Y in the respiratory gas stream i The transport of can generally be described by the following transport equation. ∂ / ∂t(ρY i )+∇·(ρY i u)=∇·(ρD ij ∇Y i )+w i The first term ∂ / ∂t(ρY i ) represents the change over time, and the second term ∇·(ρYi u) represents convective transport, and the third term ∇·(ρD ij ∇Y i ) represents diffusive transport, and the last term w i represents a source or sink. The diffusive transport mechanism is relatively weak and is hindered by long diffusion distances and small transport coefficients. For example, diffusive transport mainly occurs in a mixing tank. Therefore, in order to achieve the desired mixing of different respiratory gas components, a relatively long residence time of the respiratory gas components in the mixing tank is required, which leads to the above-mentioned drawbacks.
[0015] In contrast to the diffusive transport mechanism, the convective transport mechanism is regarded as a very strong transport mechanism. According to the present invention, this transport mechanism is advantageously utilized by generating vortices as desired to mix various respiratory gas components.
[0016] The introduction of various respiratory gas components, which may each be air, a gas or a gas mixture, into the mixing device is carried out via at least two inlets. In particular, when three or more respiratory gas components are to be mixed with each other, three or more inlets are conceivable. These inlets are arranged in the flow path, for example, such that the respiratory gas component flows extend spatially side by side inside the first flow path portion and a laminar flow of the respiratory gas components is formed. In the region of the contact surface where the respiratory gas component flows are adjacent to each other, the mixing of different respiratory gas components is at least partially already carried out by the diffusion process. The laminar flow of the respiratory gas components flows in the direction of the transition portion from the first flow path portion to the second flow path portion. Furthermore, it is conceivable that the inlets are arranged in the flow path such that the respiratory gas component flows cross each other at least partially inside the first flow path portion and / or the individual respiratory gas component flows are deflected.
[0017] A suitable layered flow, i.e., a flow in which different breathing gas component flows are arranged in layers, is accelerated through the decreasing cross-section of the first channel and introduced, for example tangentially, into the second channel with a higher flow impact in the transition region. Tangential introduction in this case means that the layered flow is introduced only in a partial region of the inner wall of the second channel, i.e., not introduced across the center or the entire cross-section of the second channel. In this case, the layered flow flows only along a partial region of the inner wall of the second channel after its introduction, while other regions of the inner wall are not in contact with the layered flow, or are in little contact, directly or during vortex formation. That is, substantially, the layered flow is in contact with the inner wall of the second channel at inflow and has an asymmetrical distribution in the second channel in the transition region. The reduction in the cross-sectional area of the first flow channel can preferably be achieved by reducing the perimeter of the first flow channel itself, or by attaching at least one additional flow guide element to the first flow channel, which deflects a portion of the layered flow and guides it to pass through a flow channel cross-section smaller than that of the first flow channel. Furthermore, it is conceivable that this additional element introduces the layered flow into the second flow channel so that a vortex flow is formed as described above.
[0018] The acceleration and tangential introduction of the layered flow, that is, the oriented introduction of the layered flow along a partial region of the inner wall of the second channel, and the inclination between the first and second channel, according to the present invention, result in the formation of vortices within the second channel. The inclination of the second channel relative to the first channel means that the longitudinal central axes of these channels are inclined toward each other at a non-zero angle. As a result, the layered flow extending along a partial region of the inner wall of the second channel collides with at least one inner wall region of the second channel that is inclined toward this partial region, causing it to be at least partially deflected and vortices to form. Furthermore, as an alternative or supplement to the preferred tangential introduction, it is conceivable to introduce the layered flow into the second channel such that the layered flow does not initially extend along a partial region of the inner wall or along multiple regions of the inner wall, or extends only partially. Importantly, the layered flow, as it progresses through the second channel, collides at least partially head-on with another inner wall region that is at least partially inclined with respect to the flow direction, and is deflected in the process, thereby forming at least partially vortices. For example, an accelerated layered flow is guided to the center of the transition from the first channel to the second channel, and as it progresses, collides with one of the inner wall regions of the second channel based on the inclination of the second channel relative to the first channel.
[0019] According to the present invention, the layered flow of the respiratory gas components extending in the first channel section forms a vortex in the second channel section, at least partially, where multiple layers of these layers of respiratory gas components are brought into contact with each other by the rotational motion of the vortex, thus doubling the number of layers of different respiratory gas components arranged side by side. For example, starting with two layers of two different respiratory gas components in a layered flow, four, six, or more layers of the two respiratory gas components are formed in the cross-section of the vortex. In other words, the respiratory gas components are distributed by convective transport by the vortex in the second channel section, increasing the contact area where different respiratory gas component flows are adjacent to each other, thereby resulting in enhanced mixing of the respiratory gas components by diffusion. The vortex flows spirally toward the outlet in at least a predetermined portion, and at this outlet, the mixed respiratory gas flow is formed by convective transport of different respiratory gas components by a mixing device of advantageously small structural size, in which case the impact on the dynamic characteristics of the ventilator or anesthesia machine is minimal.
[0020] Advantageously, various respiratory gas components can be mixed by such a mixing device. In this case, the required structural space is significantly reduced compared to conventional mixing tanks in ventilators or anesthesia machines, allowing for a smaller structural size and a larger dynamic area in the ventilator or anesthesia machine. Thus, setting changes in the ventilator or anesthesia machine, such as changing the concentration of one of the respiratory gas components, can be performed quickly and with a small pressure drop. Furthermore, this structure can be manufactured more easily than static mixers. Unlike motor-driven mixers, there is no need for an active drive mechanism, and therefore no complex structure or higher energy consumption. Vortices are generated only by the simpler structure and existing flow of the mixing device according to the present invention. Thus, the mixing device can be easily manufactured, and manufacturing costs are kept within an economically significant range.
[0021] In a preferred embodiment, the first and second flow channels are positioned substantially perpendicular to each other in the transition region. The inclination between the flow channels helps in the formation of vortices in the second flow channel. Particularly advantageous for vortex formation is an inclination of approximately 90° between the first and second flow channels. In this case, the longitudinal central axes are positioned substantially perpendicular to each other, and the layered flow in the first flow channel collides with the edge region of the second flow channel in the flow direction based on this inclination, thereby deflecting the flow and forming vortices. The generation of vortices is particularly pronounced when the first flow channel is positioned substantially perpendicular to the second flow channel, thus improving the mixing of different breathing gas components. Furthermore, a particularly stable vortex is formed when the flow passes through the second channel, in which case the flow direction extends around the longitudinal central axis of the second channel, that is, the longitudinal central axis substantially forms the center of the vortex, and therefore flows toward the outlet in accordance with the geometry of the second channel. A further advantage of the nearly perpendicular arrangement of the first and second channel is a more compact structural form, which in turn saves space when incorporated into a ventilator or anesthesia machine.
[0022] In a particularly preferred embodiment of the mixing device, the first and / or second flow channels have a rectangular cross-section in at least a predetermined portion. In this case, the cross-section may be rectangular or, particularly preferably, square in shape. An advantage in this respect is improved use of structural space when the mixing device is incorporated into a ventilator or anesthesia machine. A rectangular cross-section in at least a portion of the second flow channel is particularly advantageous, in which case vortices at the four corners create secondary vortices within the second flow channel, and these secondary vortices improve the mixing of different respiratory gas components.
[0023] In a preferred embodiment of the mixing device, the first flow path section and / or the second flow path section is formed in the form of a cylinder, a frustum of a cone, or a frustum of a pyramid at least in a predetermined portion. The substantially circular cross-section of the first flow path section and / or the second flow path section has the advantage, for example, that a breathing gas hose can be easily attached to the inlet and / or outlet of the mixing device. A at least partially circular cross-section of the second flow path section is particularly advantageous, in which case a particularly stable vortex flow is formed that flows spirally and guided from the second flow path section in the direction of the outlet at least in a predetermined portion.
[0024] According to a preferred embodiment of the mixing device, at least two inlets have a substantially circular cross-section. This has the advantage that a breathing gas hose can be attached to the inlet particularly easily.
[0025] In a preferred embodiment of the mixing device, the cross-section of the first flow path section decreases by more than 50% until it reaches the transition section to the second flow path section. Preferably, the cross-section decreases uniformly from the region of the inlet to the transition section to the second flow path section. Furthermore, it is conceivable that the decrease in the cross-section occurs only in a partial region of the first flow path section. For example, the cross-section decreases by more than 50% from the center of the first flow path section until it reaches the transition section to the second flow path section. It is also conceivable that the reduction in the cross-section is formed only immediately before the transition section to the second flow path section. The special advantage of the cross-section decreasing by more than 50% is that the resulting flow impact of the laminar flow is strong enough to promote the formation of vortices in the second flow path section. Therefore, it is possible to advantageously form vortices, particularly for the typical volume flows of ventilators or anesthesia devices in the range of 1 l / min to 180 l / min.
[0026] According to a preferred embodiment of the mixing device, the first flow path section and / or the second flow path section has a mixing element for mixing the respiratory gas components. The mixing element may be, for example, a static mixer or a similar geometry incorporated into the first flow path section and / or the second flow path section. In this case, the laminar flow in the first flow path section and / or the turbulent flow in the second flow path section impinge on the mixing element, and additional mixing of the respiratory gas components is performed. Advantageously, when incorporated into a ventilator or anesthetic machine, improved mixing of the respiratory gas components at the outlet of the mixing device is achieved by a suitable mixing element without the need to provide additional structural space without enlarging the mixing device. In this case, it is desirable that the outer dimension of the mixing element corresponds to or is smaller than the inner circumference of the first flow path section or the second flow path section. Furthermore, it is desirable that the mixing element has as little flow resistance as possible. It is conceivable to incorporate one or more mixing elements into the first flow path section and / or the second flow path section. Furthermore, it is conceivable that the mixing elements provided inside the mixing device have various structures.
[0027] In a preferred embodiment of the mixing device, at least two inlets are arranged substantially side by side, thereby creating a laminar flow of the respiratory gas components in the first flow path section. Such an arrangement of the inlets results in a special laminar flow in which the respiratory gas component flows extend substantially side by side and their flow velocities are maintained substantially the same, i.e., the flow is not weakened. This advantageously promotes the formation of vortex rolls in the second flow path section.
[0028] According to a preferred embodiment of the mixing apparatus, one buffer volume is located downstream of each of the two inlets of the first flow channel, and the cross-sections of these buffer volumes are substantially circular. Preferably, the buffer volumes are cylindrical, and the respiratory gas component flow preferably flows directly into the buffer volumes from the inlets. The cross-sections of the buffer volumes preferably correspond to the cross-sections of each inlet, so that each buffer volume can be filled with incoming respiratory gas components as quickly as possible. In this case, the buffer volumes preferably have a size in the range of 25 to 35 ml, and particularly preferably 30 ml. The respiratory gas component flow is introduced into each buffer volume via the inlets, and these buffer volumes are filled with a corresponding amount of respiratory gas components. A layered flow is also formed when the respiratory gas component flow flows out of the buffer volumes inside the first flow channel. This layered flow can be achieved, for example, by the arrangement of the outlets of the buffer volumes or by the shape of the first flow channel. Furthermore, between these buffer volumes, there are fluid communication sections in the form of channels that open tangentially into the buffer volumes. Through this channel, the respiratory gas components are exchanged between buffer volumes. In this case, the respiratory gas component flow flows from one buffer volume to the other through this channel. If no further exchange is needed, the channel between the buffer volumes can be closed.
[0029] Furthermore, the present invention relates to a ventilator or anesthesia machine equipped with a mixing device formed according to the embodiments described above. The respiratory gas components required for artificial respiration are introduced into the ventilator or anesthesia machine, for example, via a central gas supply unit, a blower, and / or connected gas cylinders, and processed according to the patient's needs. This includes, for example, setting a predetermined concentration of oxygen introduced into the mixing device along with air, so that a preset oxygen concentration is obtained in the respiratory gas flow ultimately formed at the outlet of the mixing device. The mixing device mixes respiratory gas components, for example, oxygen and air, and the different respiratory gas components are distributed substantially uniformly across the flow cross-section, so that the concentration of respiratory gas components in the respiratory gas flow flowing out through the outlet of the mixing device can be precisely defined. In this case, the respiratory gas component flow, for example, air, oxygen, and / or anesthetic gas, is introduced into a first flow path through the inlet of the mixing device. It is conceivable that the mixing device has three or more inlets and therefore can mix three or more respiratory gas components, for example, three or more respiratory gas components. The breathing gas component flow in the first channel section undergoes acceleration in its path to the transition to the second channel section, achieved by a reduction in at least a predetermined portion of the cross-section of the first channel section. This acceleration results in increased flow impact, which, along with the directional introduction of the breathing gas component flow into the second channel section, contributes to the formation of a vortex. In this case, the breathing gas component flow is preferably guided tangentially into the second channel section. Since the second channel section is positioned at an angle to the first channel section, the introduced breathing gas component flow collides with the inner wall region of the second channel section, which is located at least partially opposite in the flow direction to the transition from the first channel section to the second channel section, i.e., the outlet of the first channel section. This deflects the breathing gas component flow, causes it to rotate about the longitudinal central axis of the second channel section, and forms a vortex. The vortex flows spirally in at least a predetermined portion toward the outlet of the mixing device. The respiratory gas stream, mixed in a favorable form, exits the mixing device through an outlet, flows along an oxygen sensor to determine, for example, the oxygen concentration, and then this mixed respiratory gas stream is supplied to the patient.The particularly good mixing of respiratory gas components in the respiratory gas stream can avoid false alarms based, for example, on concentration gradients present in the respiratory gas stream and the resulting localized concentration peaks in the respiratory gas stream. Furthermore, the respiratory gas concentrations measured without such concentration peaks due to insufficient mixing simplify the adjustment of the concentration ratios of respiratory gas components, because in this case, there is no need to average the concentration values and / or filter them.
[0030] Furthermore, the present invention relates to a method for manufacturing such a mixing apparatus, wherein at least one manufacturing step is part of an injection molding method or a 3D printing method. The injection molding method is advantageously suited for mass production of the mixing apparatus. The 3D printing method is advantageous for manufacturing as quickly as possible. The mixing apparatus according to the present invention is configured such that both manufacturing methods can be implemented with minimal effort.
[0031] Further features, problems, and effects of the present invention are evident from the detailed description and accompanying drawings. Embodiments of the present invention are described without limiting the overall idea of the invention. [Brief explanation of the drawing]
[0032] [Figure 1] This is a schematic cutaway view of a mixing apparatus, including a streamline representation of the breathing gas flow. [Figure 2] This is a schematic cross-sectional view of the flow path of a mixing device, including the streamline representation of the breathing gas flow. [Figure 3] This is a schematic diagram showing a preferred embodiment of a mixing apparatus equipped with a buffer volume. [Figure 4] This is a schematic diagram showing a preferred embodiment of a mixing apparatus equipped with a mixing element.
[0033] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In this description, similar components in multiple drawings are denoted by the same reference numerals.
[0034] Figure 1 shows a preferred embodiment based on a schematic diagram of the mixing device 1, in which case the casing of the mixing device 1 is shown transparently, and the streamlines 13a, 13b, 13c, 14a, 14b, and 14c of the flowing breathing gas are additionally shown. In this case, three exemplary streamlines 13a, 13b, and 13c of the first breathing gas component flow and three streamlines 14a, 14b, and 14c of the second breathing gas component flow are shown, and the streamlines of both breathing gas component flows are mixed to form a single breathing gas flow as described below. The mixing device 1 includes a first inlet 2 and a second inlet 3 for introducing two types of breathing gas components, a first flow path section 4, a second flow path section 5, and a transition section 6 from the first flow path section 4 to the second flow path section 5. Furthermore, the mixing device 1 has an outlet 7 for discharging the mixed breathing gas.
[0035] In the embodiment shown in Figure 1, air and oxygen, which are breathing gas components, are mixed. In this case, air is introduced into the first flow channel 4 through the first inlet 2, and oxygen is introduced through the second inlet 3. By configuring the first inlet 2 and the second inlet 3, a layered flow 11 is formed in the first flow channel 4, where the breathing gas component flows consisting of air and oxygen extend substantially parallel to each other and have regions where the breathing gas component flows are adjacent to each other. The cross-section of the first flow channel 4 decreases downstream to a transition section 6, thereby accelerating the layered flow. The accelerated layered flow 11 then flows tangentially into the second flow channel 5. In this case, the layered flow passing through the decreasing section of the cross-section of the first flow channel 4 is first introduced into the second flow channel 5, extending mainly along the first inner wall region 9. The layered flow 11 then collides with a second inner wall region 10, which is positioned substantially perpendicular to the flow direction of the layered flow 11. As a result, the layered flow 11 is redirected so that a vortex flow 12 is formed, that is, a flow extending in a circular shape around a single axis. The vortex flow 12 flows spirally towards the outlet 7 around the longitudinal central axis 8 of the second flow channel 5, and at this time, the breathing gas components, air and oxygen, are mixed inside the vortex flow 12.
[0036] Figure 2 shows a schematic cross-section of the flow path section of the mixing device 1, including the streamlines of the breathing gas flows 21 and 22. In this case, a side view of the mixing device is shown, which is a plan view in the direction of extension of the longitudinal central axis 8 of the second flow path section 5 shown in Figure 1. The breathing gas components, air and oxygen, are introduced into the first flow path section 4 through the first inlet 2 and the second inlet 3, where the first breathing gas component flow 21 and the second breathing gas component flow 22 are formed. The layered breathing gas component flows 21 and 22, having a planar contact area, flow to the transition section 6 in the direction of the arrow, and then from the first flow path section 4 to the second flow path section 5, in which case these breathing gas component flows are accelerated by the reduction in the cross-sectional area of the first flow path section 4. This acceleration increases the flow impact of the respiratory gas component flows 21 and 22, guiding them into the second flow channel 5, which is inclined relative to the first flow channel 4. As a result, the layered respiratory gas component flows 21 and 22 collide with the inner wall region of the second flow channel 5, are deflected, and ultimately form a vortex flow 12 that propagates toward the outlet 7. Within the vortex flow 12, the adjacent contact surfaces of the layered respiratory gas component flows 21 and 22 are doubled, and at this time, the different respiratory gas components, air and oxygen, are mixed in a particularly favorable manner. This is due to the convective transport of the respiratory gas components of the respiratory gas component flows 21 and 22 generated by the vortex flow 12. Through this convective transport, which is a particularly powerful transport mechanism, the respiratory gas components are distributed almost uniformly within the second flow channel 5, thereby increasing the contact area of the respiratory gas component flows 21 and 22, and enhancing the mixing of the respiratory gas components by diffusion.
[0037] Figure 3 shows a schematic diagram of a preferred embodiment of the mixing device 30 according to the present invention. For clarity, a portion of the mixing device 30 has been omitted so that its internal structure can be recognized. The mixing device 30 includes a first inlet 2 and a second inlet 3 for introducing two types of breathing gas components, a first flow path section 4, a second flow path section 5, a transition section 6 from the first flow path section 4 to the second flow path section 5, and an outlet 7 for discharging the mixed breathing gas. Furthermore, the mixing device 30 includes a first buffer volume 31 connected downstream of the first inlet 2 in the flow direction, a second buffer volume 32 connected downstream of the second inlet in the flow direction, and a flow path 34 between the buffer volumes 31 and 32. Additionally, a flow guide element 33 is incorporated into the first flow path section 4. The flow guide element 33 reduces the cross-sectional area of the first flow channel 4, changing the direction of extension of the first flow channel 4 so that the respiratory gas component flow from the first flow channel 4 is introduced tangentially into the second flow channel 5, and a vortex flow is formed in the second flow channel 5. Within this vortex flow, different respiratory gas components are mixed, and the mixed respiratory gas flow flows out from the mixing device 30 via the outlet 7.
[0038] Figure 4 shows a schematic diagram of another preferred embodiment of the mixing device 40 formed according to the present invention, in which case the mixing device 40 is shown transparently for better clarity. The mixing device 40 also includes a first inlet 2 and a second inlet 3 for introducing two breathing gas components, a first flow path section 4, a second flow path section 5, a transition section 6 from the first flow path section 4 to the second flow path section 5, and an outlet 7 for discharging the mixed breathing gas. In this embodiment, a first mixing element 41 is incorporated into the first flow path section 4, and a second mixing element 42 is incorporated into the second flow path section. The first mixing element 41 and the second mixing element 42 are formed in the form of a static mixer without movable members. The first mixing element 41 redirects the layered flow 11, which includes the breathing gas component flows 21 and 22, in various directions as shown in Figure 2. This causes the breathing gas component flows to intersect, and consequently, distribution and mixing of the breathing gas components already occur in the first flow channel section 4, resulting in additional mixing of different breathing gas components. Similarly, as shown in Figure 1, for example, additional mixing of breathing gas components within the vortex flow 12 occurs in the second mixing element 42 in the second flow channel section 5. Here, the vortex flow 12 is guided by a mesh-like structure consisting of multiple flow channels extending in different directions, thereby distributing the breathing gas components and resulting in additional mixing. [Explanation of Symbols]
[0039] 1 Mixing device 2. First entrance 3. Second entrance 4. First flow channel section 5. Second flow channel section 6. Transition Section 7 Exit 8. Longitudinal central axis 9. First inner wall region 10 Second inner wall region 11 Layered flow 12 vortex rolls 13a, 13b, 13c Streamlines of the first respiratory gas component stream 14a, 14b, 14c Streamlines of the second respiratory gas component stream 21. First respiratory gas component flow 22 Second respiratory gas component flow 30 Preferred Embodiments of Mixing Apparatus 31 First buffer volume 32 Second buffer volume 33 Flow guide element 34 Flow channels between buffer volumes 40 Another Preferred Embodiment of a Mixing Apparatus 41 First Mixing Element 42 Second Mixing Element
Claims
1. A mixing device (1) for a ventilator or anesthesia machine for mixing at least two respiratory gas components, the mixing device (1) having a flow path including a first flow path section (4) having at least two inlets (2, 3) for introducing the respiratory gas components, and a second flow path section (5) having an outlet (7) for discharging a respiratory gas flow containing the mixed respiratory gas components, A mixing device (1) characterized in that the cross-section of the first flow path section (4) decreases in a predetermined portion toward the downstream direction toward the transition section (6) from the first flow path section (4) to the second flow path section (5), the first flow path section (4) and the second flow path section (5) are inclined toward each other in at least the region of the transition section (6), and the first flow path section (4) opens to the second flow path section (5) such that a vortex flow (12) of the breathing gas flow, centered on a longitudinal central axis (8), flows spirally in at least a predetermined portion toward the outlet (7) in the region of the transition section (6), and is formed at least partially within the second flow path section (5).
2. The mixing apparatus (1) according to claim 1, characterized in that the first flow channel (4) and the second flow channel (5) are arranged substantially perpendicular to each other in the region of the transition section (6).
3. The mixing apparatus (1) according to claim 1 or 2, characterized in that the first flow channel (4) and / or the second flow channel (5) have a rectangular cross-section in at least a predetermined portion.
4. The mixing apparatus (1) according to claim 1 or 2, characterized in that the first flow channel (4) and / or the second flow channel (5) are formed in a cylindrical, truncated cone, or truncated pyramidal shape in at least a predetermined portion.
5. The mixing apparatus (1) according to any one of claims 1 to 4, characterized in that the at least two inlets (2, 3) have substantially circular cross-sections.
6. The mixing apparatus (1) according to any one of claims 1 to 5, characterized in that the cross-section of the first flow channel (4) decreases by more than 50% by the time it reaches the transition section (6) to the second flow channel (5).
7. The mixing apparatus (1) according to any one of claims 1 to 6, characterized in that the first flow channel (4) and / or the second flow channel (5) have mixing elements (41, 42) for mixing the respiratory gas components.
8. The mixing apparatus (1) according to any one of claims 1 to 7, characterized in that the at least two inlets (2, 3) are arranged substantially side by side, and a layered flow (11) of the breathing gas components is generated in the first flow path section (4) from the inlets.
9. A mixing apparatus (1) according to any one of claims 1 to 8, characterized in that one buffer volume (31, 32) is arranged downstream of at least two inlets (2, 3) of the first flow path section (4), the cross-section of the buffer volume (31, 32) is substantially circular, and between the buffer volume (31, 32) there exists a fluid communication section in the form of a flow path (34) that opens tangentially into the buffer volume (31, 32).
10. A ventilator or anesthesia machine comprising a mixing device (1) according to at least one of claims 1 to 9.
11. A method for manufacturing a mixing apparatus (1) according to any one of claims 1 to 9, wherein at least one manufacturing step is part of an injection molding method or a 3D printing method.