FLUID CONTROL ORDER FOR A MEDICAL DEVICE

Description

[0001] The invention relates to a fluid control arrangement for a medical device. The fluid control arrangement allows the volumetric or mass flow rate of a fluid, in particular a gas for medical applications, to be controlled or regulated.

[0002] Devices for fluid control are known from various technical fields. US 5,888,390 A describes a miniature arrangement of foldably connected metallic plates, in the inner surfaces of which fluid channel recesses are etched. Folding the plates together creates a multilayered structure for guiding fluids. Due to its miniaturization, this arrangement is suitable for analytical instruments, such as chromatographs.

[0003] DE 195 46 535 A1 discloses a method and a device for sample collection with integrated analytical-chemical sensor measurement and a method for manufacturing the device. A measuring cartridge is equipped with chemo- or biosensors and can be connected between the needle and syringe via Luer connectors. After sample collection using the syringe, the measuring cartridge can be inserted into a handheld measuring device.

[0004] From US 5,020,373 A, a flow meter is known that includes a flow sensor arranged in a channel section of a flow channel with a reduced diameter. Downstream in the flow direction, a vortex generator and a pressure measuring channel are arranged. The generated vortex frequencies are a function of the flow rate, which can be detected via the pressure measuring channel.

[0005] WO 99 / 36747 A1 discloses a device and a method for detecting fluid flow as a function of the pressure difference between two ports in a flow channel.

[0006] US 2005 / 0011282 A1 describes a device for the optical indication of fluid flow. A circuit with a flow sensor controls an LED depending on the gas flow through a housing. The housing consists of two parts that contain the circuit. The circuit is mounted on a printed circuit board. Gas can flow in through one housing part and out through the other.

[0007] US 9 374 891 B2 describes a printed circuit board (PCB) containing a carrier for a circuit.

[0008] From DE 101 27 261 A1, a measuring device for the flow rate of a gas is known, which has two flow sensors. The flow sensors are arranged in a flow chamber and have different measuring characteristics.

[0009] Insert US 2017 / 059376 A1 discloses a flow measurement system for detecting intravenous drug delivery. A flow sensor is part of the system and is interchangeably mounted on a base. The flow sensor has a flow tube with an inlet and an outlet through which the medium to be measured flows. Two piezoelectric sensors are arranged at a distance in the direction of flow, and their signals are evaluated in an electrical circuit to determine the flow rate.

[0010] US 2018 / 335331 A1 generally concerns a flow meter with a sensor array. To measure the flow rate, fluid can be introduced into an arc-shaped pipe section to set it into vibration. This generates Coriolis forces, which create a phase difference in the vibration in the direction of flow. Sensors at different positions along the pipe can measure its movement, and the mass flow rate through the pipe can be determined from the phase shift.

[0011] Based on the prior art, the object of the present invention can be considered to be to create an improved fluid control arrangement for a medical device. In particular, the fluid control arrangement should be designed to control the flow of a medical gas while enabling a compact and cost-effective design.

[0012] This problem is solved with the fluid control arrangement having the features of claim 1.

[0013] The fluid control arrangement is specifically designed to control or regulate the flow of a gas such as argon, oxygen, carbon dioxide, or another gas used in a medical device. In other medical applications, a liquid flow can also be controlled or regulated instead of a gas flow. The medical device in question may, in particular, be an argon plasma coagulation device.

[0014] The fluid control arrangement has a fluid control circuit comprising a fluid channel arrangement and at least one fluid control component. The fluid channel arrangement and the fluid control component are arranged between an inlet port and an outlet port and together form a fluidic connection between the inlet port and the outlet port. Preferably, at least one fluid control component, or all of the fluid control components present, are fluid-flowed through during operation of the fluid control arrangement. A fluid control component can be, for example, a directional control valve, a proportional valve, a pressure control valve or pressure regulating valve, a filter, or another fluid-flowable component that not only guides a fluid but also influences a fluid property (e.g., pressure, volume flow rate, mass flow rate, purity) of the fluid flowing through it.

[0015] A control circuit is configured to control at least one fluid control component of the fluid control circuit. For this purpose, the control circuit comprises at least one electrical and / or electronic component, including, for example, a control unit, which provides electrical control signals for the at least one fluid control component. Preferably, the control circuit does not include any components through which fluid flows. One or more components of the control circuit, for example, pressure sensors, may be in contact with the fluid, but are preferably not fluid-filled.

[0016] The fluid control arrangement preferably comprises a first support part with a first mounting surface and a first coupling surface, and a second support part with a second mounting surface and a second coupling surface. The mounting surface and the coupling surface of each support part are preferably arranged on opposite sides of the respective support part. In one embodiment, the first mounting surface and / or the second mounting surface each extend in the same plane. The first mounting surface is designed for attaching at least one fluid control component.The second mounting surface is designed for attaching at least one electrical and / or electronic component of the control circuit. One or more fluid control components of the fluid control circuit are arranged on the first mounting surface of the first support part and / or one or more components of the control circuit are arranged on the second mounting surface of the second support part. It is preferred if all fluid control components of the fluid control circuit and / or all components of the control circuit are arranged directly or indirectly on the respective mounting surface.

[0017] In one embodiment, some or more of the existing fluid control components are arranged directly on the first mounting surface and fluidically connected to the fluid channel arrangement. A printed circuit board assembly can be attached to the second mounting surface, carrying at least one electrical and / or electronic component of the control circuit. Preferably, all electrical and / or electronic components of the control circuit are arranged on the printed circuit board assembly.

[0018] It is also advantageous if no components are attached to the first support part and / or the second support part outside the respective mounting area.

[0019] To form at least one main fluid channel of the fluid channel arrangement, at least one first fluid channel recess can be provided in the first coupling surface and / or at least one second fluid channel recess in the second coupling surface. The first and second support parts can be connected to each other in the area of ​​the first and second coupling surfaces. The coupling surfaces can each have a surface section – preferably flat – that either directly abuts each other or faces each other, forming a gap. These surface sections surround the fluid channel recesses of the support parts. The at least one first and second fluid channel recess is recessed relative to the surrounding surface section of the first and second coupling surfaces, respectively.When the two support parts are connected at their coupling surfaces, the first fluid channel recess, together with the second support part, and / or the second fluid channel recess, together with the first support part, define a main fluid channel at the interface between the two support parts. The support parts are connected at their coupling surfaces in such a way that the at least one main fluid channel at the interface between the two support parts is fluidically sealed, optionally using a sealing arrangement.

[0020] The at least one main fluid channel is preferably located exclusively in the area of ​​the separation point or separation plane between the support parts and is bounded by both support parts. Further fluid channels of the fluid channel arrangement can run within the first support part and / or the second support part and, in particular, form branch channels to or from a fluid channel recess. Preferably, all fluid channels of the fluid channel arrangement are bounded by channel walls that are either an integral part of the first support part or an integral part of the second support part. Within the fluid control circuit between the inlet port and the outlet port, preferably no fluidic connection is formed by a separate line that runs completely outside the support parts, for example, directly between two fluid control components.

[0021] It is preferred that each main fluid channel is formed by a first fluid channel recess in the first support part and a second fluid channel recess in the second support part. Each first and / or second fluid channel recess preferably has a semicircular cross-section. Thus, when the support parts are connected, each main fluid channel can have a circular cross-section. At least some of the main fluid channels preferably have a substantially circular cross-section.

[0022] The fluid channel arrangement can have at least one fluidic branch channel branching off from a main fluid channel. For example, the first support section can have at least one fluidic first branch channel extending between the first mounting surface and the first coupling surface. Similarly, the second support section can have at least one fluidic second branch channel extending between the second mounting surface and the second coupling surface.

[0023] For the production of the support components, it is particularly advantageous if the first and second support components are each formed by a single injection-molded part. Preferably, the injection-molded parts are made of a uniform material, in particular a plastic or composite material. The first and second support components are thus designed as integral support components without seams or joints. In particular, no material-removing post-processing is required after the production of the support components to form fluid channels. Preferably, all fluid channels of the fluid channel arrangement are formed during and by the production of the support components.

[0024] If the first support component has at least one first branch channel, this first branch channel is free of undercuts in at least one direction extending from the first mounting surface to the first coupling surface, or vice versa. The first branch channel can be conical or cylindrical. If the first support component has at least one second branch channel, this second branch channel is free of undercuts in at least one direction extending from the second mounting surface to the second coupling surface, or vice versa. This second branch channel can also be conical or cylindrical. This significantly simplifies the production of the support components as injection-molded parts.

[0025] Preferably, all recesses extending transversely to the mounting and coupling surfaces are free of undercuts, at least in one direction from the respective coupling surface to the respective mounting surface or vice versa. The at least one first branch channel and / or the at least one second branch channel extend, in particular, in a forming direction of an injection mold for producing the first support part or the second support part as an injection-molded part.

[0026] The above-described manufacture of the support parts as injection-molded parts and / or the undercut-free design of the at least one branch channel is an independent aspect of the invention and can be provided in particular independently of whether the fluid control components of the fluid control circuit and / or the components of the control circuit are arranged on the mounting surfaces.

[0027] Preferably, a sealing arrangement is provided between the first coupling surface and the second coupling surface to seal the at least one main fluid channel. The sealing arrangement can include a ring seal for each main fluid channel. If several separate main fluid channels are formed in the area of ​​the separation point or separation plane between the support parts, each main fluid channel is preferably completely enclosed by a ring seal of the sealing arrangement to seal the main fluid channel from the environment. For this purpose, an annular groove for inserting the ring seal can be provided either in the first coupling surface and / or in the second coupling surface. The annular groove can completely enclose a first fluid channel recess in the first coupling surface, or the annular groove can completely enclose a second fluid channel recess in the second coupling surface.

[0028] It is also advantageous if the first support part and / or the second support part is at least partially made of a transparent material, so that, once the connection between the support parts has been made, it can be visually inspected from the outside to determine whether the sealing arrangement is correctly positioned in the area of ​​the joint between the two support assemblies. In particular, it can be assessed whether the at least one ring seal is correctly positioned in the associated annular groove.

[0029] Preferably, all fluid-flowing fluid control components of the fluid control unit are arranged on the first mounting surface, and in particular directly. Additionally or alternatively, all electrical and / or electronic components of the control circuit are arranged indirectly or directly on the second mounting surface, preferably indirectly via a printed circuit board arrangement. Preferably, none of the components of the control circuit are fluid-flowing.

[0030] According to the invention, a main fluid channel of the fluid channel arrangement forms a flow measurement channel. The flow measurement channel is part of a flow measurement device of the fluid control arrangement. The flow measurement channel preferably has a substantially circular cross-section at every point. Two pairs of pressure measurement channels, each with two pressure measurement channels, are provided, which open into the flow measurement channel at a distance from each other in the flow direction. The pressure measurement channels of a pressure measurement channel pair are preferably located in the same support part, but can alternatively be located in different support parts. Preferably, the pressure measurement channels run at least partially in and through the second support part. In a preferred embodiment, each of the pressure measurement channels is assigned a separate pressure sensor, which is configured to measure the pressure in the pressure measurement channel and thus at the opening between the respective pressure measurement channel and the flow measurement channel.Alternatively, a differential pressure sensor can be connected to the pressure measurement channels of a pressure measurement channel pair, so that a single differential pressure sensor is sufficient for each pressure measurement channel pair. The differential pressure sensor is configured to generate a differential pressure signal, which is then transmitted to the control unit.

[0031] At least one section of each pressure measuring channel can be formed by a branch channel as described above. In a preferred embodiment, a further section of each pressure measuring channel can run in a nozzle extending beyond the mounting surface, which is in particular formed integrally with the associated support part.

[0032] According to the invention, a first pressure measuring channel pair and a second pressure measuring channel pair are provided, the pressure measuring channels of which open into the same flow measuring channel. The flow measuring channel has a first channel section with a first flow cross-section and a second channel section with a second flow cross-section, wherein the two flow cross-sections are of different sizes. The pressure measuring channels of the first pressure measuring channel pair open into the first channel section, and the pressure measuring channels of the second pressure measuring channel pair open into the second channel section. In this embodiment, it is possible to perform a flow measurement with each pressure measuring channel pair, whereby different measuring ranges for determining the volumetric flow rate or the mass flow rate of the fluid flow are possible due to the different flow cross-sections. Overall, the total available measuring range is thereby increased.

[0033] To determine the volumetric flow rate or mass flow rate of the fluid through the flow measurement channel, an evaluation unit of the control circuit is preferably provided, to which the measured pressure values ​​of at least one pair of pressure measurement channels assigned to a common pressure measurement channel pair are transmitted. Due to pipe friction in the flow measurement channel, a differential pressure arises between the pressure measurement channels of a common pressure measurement channel pair, which is characteristic of the volumetric flow rate or mass flow rate of the fluid through the flow measurement channel and can thus be determined in the evaluation unit.

[0034] The above-described design of the flow measuring device, in particular the flow measuring channel and / or the pressure measuring channels and / or the connected pressure sensors, can also be implemented additionally or alternatively to other aspects of the invention.

[0035] It is also preferred if the fluid control circuit comprises a series connection of an actuator, in particular a proportional valve, and a flow measuring device. The flow measuring device can be configured as described above. In the direction of flow, the flow measuring device is preferably located upstream of the actuator. This ensures flow measurement independent of the load connected to the output port, for example, a surgical instrument.

[0036] It is further advantageous if the flow measuring device is located in the flow direction between a pressure limiting device or a pressure control or pressure regulating device and the actuator. Preferably, no additional fluid control components – in particular, no fluid control components influencing the fluid pressure – are present between the pressure limiting device or the pressure control or pressure regulating device and the actuator, except for those belonging to the flow measuring device.

[0037] The circuit design of the fluid control circuit with regard to the hydraulic circuit diagram, in particular the arrangement of the flow measuring device in series with other fluid control components, can be used independently of or in addition to the previously described features of the fluid control arrangement and is in particular independent of whether the components of the fluid control circuit and / or the control circuit are arranged on the mounting surfaces of the support parts.

[0038] Advantageous embodiments of the invention are described in the dependent claims and the drawings. Preferred embodiments of the invention are explained in detail below with reference to the accompanying drawings. These show: Figure 1 a block diagram of an exemplary embodiment of a medical device in the form of an argon plasma coagulation device, Figure 2 a hydraulic block diagram of an exemplary embodiment of a fluid control circuit for the device from Figure 1 , Figure 3 a schematic representation of an embodiment of a fluid control arrangement comprising a fluid control circuit and a control circuit arranged on support parts, Figure 4a schematic representation of an embodiment of a first support part in a top view of a first coupling surface of the first support part, as well as a schematic representation of an embodiment of a sealing arrangement, Figure 5 the first support part made of Figure 4 in a sectional view according to section line VV in Figure 4 , Figure 6 a schematic representation of an embodiment of a second support part in a top view of a second coupling surface of the second support part, Figure 7 the second support part according to Figure 6 in a schematic side view according to arrow VII in Figure 6 , Figure 8 a schematic sectional view through the interconnected support parts of the fluid control arrangement according to Figure 3 , Figure 9 a schematic representation of the arrangement of a pressure sensor of the control circuit and Figure 10A schematic representation of an exemplary embodiment of a flow measuring device for the fluid control arrangement.

[0039] Figure 1 Figure 10 shows a medical device 10, for example, an argon plasma coagulation device. The medical device 10 has a fluid source 11 to which a fluid control arrangement 12 is fluidically connected. An instrument can be connected to the fluid control arrangement 12, through which the fluid flow provided by the fluid control arrangement 12 can be directed. In the embodiment of the medical device 10 illustrated here, a high-voltage source 14 is also provided for supplying a high voltage to the instrument 13. The instrument 13 can be electrically connected to the high-voltage source 14.

[0040] In the exemplary embodiment, the fluid control arrangement 12 provides an argon gas flow for the instrument 13, which flows around an electrode 15 at the outlet end of the instrument 13. A high voltage can be applied to the electrode 15 for argon plasma coagulation.

[0041] The in Figure 1 The illustrated medical device 10 is merely an example. The fluid control arrangement 12 according to the invention can also be used for other medical devices 10.

[0042] The fluid control arrangement 12 comprises a fluid control circuit 19 and a control circuit 20. The fluid control circuit 19 includes at least one, and in the exemplary embodiment several, fluid control components 21, which are fluidically connected to a fluid channel arrangement 22 of the fluid control circuit 19. The fluid channel arrangement 22 and the fluid control components 21 establish a fluidic connection between an input port 23 and an output port 24 of the fluid control arrangement 12 or the fluid control circuit 19. The fluid source 11 can be connected to the input port 23. The instrument 13 can be fluidically connected to the output port 24.

[0043] The fluid control components 21 are fluid-flowed. In the exemplary embodiment, the fluid control circuit 19 comprises a switching valve 26, a pressure regulating valve 27, and a proportional valve 28 as actuators. Optionally, the fluid control circuit 19 can also include a filter 29. The filter 29 is preferably arranged downstream immediately following the inlet port 23.

[0044] In the exemplary embodiment, the control circuit 20 comprises a control unit 30 that provides at least one control signal S for at least one controllable fluid control component 21. For example, at least the switching valve 26 and the proportional valve 28 can each be controlled by a control signal S from the control unit 30. At least one input signal E can be transmitted to the control unit 30; for example, the at least one input signal E can be a sensor signal or a measurement signal. In the Figure 2In the illustrated embodiment, several sensor units 31 are provided, which supply different input signals E in the form of sensor signals. For example, the input pressure at the input port 23 or the filter 29 can be detected by one pressure sensor and the output pressure at the output port 24 by another pressure sensor and transmitted to the control unit 30.

[0045] Furthermore, in the exemplary embodiment, the fluid control arrangement 12 includes a flow detection device 32 that detects a volumetric flow rate or mass flow rate along a flow measurement channel 33 of the fluid channel arrangement 22, or signals characterizing the volumetric flow rate or mass flow rate. According to the hydraulic diagram from Figure 2The fluid control circuit 19 has a circuit arrangement in which the flow sensing device 32 is located upstream of the proportional valve 28. The proportional valve 28, which is the actuator for controlling the mass or volume flow to the instrument 13, is preferably located upstream immediately before the outlet port 24. It is for example provided that the pressure control valve 27 is located upstream of the flow sensing device 32, so that a predetermined fluid pressure prevails upstream of the flow sensing device 32, which is present at the inlet side of the flow measuring channel 33. The switching valve 26, which can be used to enable or block the fluid flow, is located upstream of the pressure control valve 27.

[0046] In the exemplary embodiment, the flow detection device 32 has two sensor units 31, each of which detects a differential pressure between two spaced-apart measuring points in the flow measurement channel 33 and transmits this data to the control unit 30. Based on the differential pressure, the control unit 30 can determine a volumetric flow rate or a mass flow rate of the fluid flowing through the flow measurement channel 33. The measuring points of the two sensor units 31 are, for example, located in different channel sections with different flow cross-sections. This allows the overall measuring range for determining the mass or volumetric flow rate to be increased.

[0047] An embodiment of the flow detection device 32 is shown schematically in Figure 10The flow measurement channel 33 is illustrated. It comprises a first channel section 33a, a second channel section 33b, and a connecting channel section 33c arranged between them. In the flow direction F of the fluid, the first channel section 33a, the connecting channel section 33c, and the second channel section 33b are arranged one after the other. The first channel section 33a has a larger flow cross-section than the second channel section 33b. In the region of the connecting channel section 33c, the flow cross-section of the flow measurement channel 33 narrows. The cross-sectional contour of the flow measurement channel 33 is preferably substantially circular.

[0048] Two pressure measuring channels 34 of a first pressure measuring channel pair 35, arranged at a distance in the flow direction F, open into the first channel section 33a. Two pressure measuring channels 34 of a second pressure measuring channel pair 36 open into the second channel section 33b of the flow measuring channel 33, also at a distance from each other, in the flow direction F. The flow cross-section of the flow measuring channel 33 does not change within each channel section 33a, 33b. Friction of the fluid as it flows along the flow measuring channel 33 generates a pressure loss between the pressure measuring channels 34 of the respective pressure measuring channel pair 35. Each pressure measurement channel 34 is connected to a pressure sensor 37, with each pressure sensor 37 generating a pressure signal and forwarding it to the control unit 30, which corresponds to the pressure of the fluid at the point where the associated pressure measurement channel 34 opens into the flow measurement channel 33.In this embodiment, the respective measuring orifice 38 is formed by the channel wall of the relevant channel section 33a between the outlets of the pressure measuring channels 34 of a common pressure measuring channel pair 35 or 36. In the control unit 30, a mass flow value or a volume flow value for the fluid through the flow measuring channel 33 can be determined from two pressure signals, in particular two pressure signals from the pressure sensors 37, which belong to a common pressure measuring channel pair 35 or 36.

[0049] It is also possible to connect a differential pressure sensor to the pressure measurement channels 34 of one or each pair of pressure measurement channels 35 or 36.

[0050] The hydraulic arrangement of the fluid control components 21 in the fluid control circuit 19 described above with respect to the flow direction F represents an aspect of the invention that can be implemented independently of the further aspects described below. By arranging the flow sensing device 32 upstream of the proportional valve 28, which represents the actuator, the measurement of the volumetric flow rate or mass flow rate can be carried out independently of the load, which is formed, for example, by the instrument 13. The setting of the proportional valve 28 is known in the control unit 30 because the setting is specified by a control signal S of the control unit 30. The setting can optionally be taken into account when determining the volumetric or mass flow rate value.

[0051] Further additional or alternative aspects of the fluid control arrangement 12 according to the invention relate to its compact and simple design and / or its manufacture and / or assembly. These aspects of the invention are described below with reference to the Figure 3-9 explained.

[0052] In Figure 3Figure 1 schematically illustrates an embodiment of the mechanical structure of the fluid control arrangement 12. In this embodiment, the fluid control arrangement 12 has a first support part 45 with a first mounting surface 46 and a first coupling surface 47, and a second support part 48 with a second mounting surface 49 and a second coupling surface 50. In this embodiment, the first mounting surface 46 is configured to support at least one fluid control component 21 of the fluid control circuit 19. The fluid control components 21 can, in particular, be attached directly to the first mounting surface 46, as shown in Figure 1. Figure 3 This is illustrated. The first mounting surface 46 and the first coupling surface 47 are, for example, opposite sides of the first support part 45. Similarly, the second mounting surface 49 and the second coupling surface 50 are opposite sides of the second support part 48.

[0053] Preferably, the first mounting surface 46 and / or the second mounting surface 49 extend in a plane. The first coupling surface 47 has, for example, a particularly continuous flat surface section 47a that extends in a plane that is preferably aligned parallel to the plane in which the first mounting surface 46 extends. The second coupling surface 50 has, for example, a particularly continuous flat surface section 50a that extends in a plane that is preferably aligned parallel to the plane in which the second mounting surface 49 extends. The support elements 45, 48 can, for example, be plate-shaped or cuboid-shaped.

[0054] The coupling surfaces 47, 50 are designed to establish a connection between the two support parts 45, 48, whereby the flat surface sections 47a, 50a of the coupling surfaces 47, 50 can be abutting each other or can be arranged facing each other, forming a gap.

[0055] The second mounting surface 49 is, for example, designed to support at least one electrical and / or electronic component of the control circuit 20. As shown in Figure 3As illustrated, several and preferably all electrical and / or electronic components 51 of the control circuit 20 are arranged on a printed circuit board assembly 52, which is attached to the second mounting surface 49. The printed circuit board assembly 52 has several component-bearing printed circuit board sections 53, which are electrically and mechanically connected to one another by means of flexible connecting sections 54. The flexible connecting sections 54 are an integral part of the two component-bearing printed circuit board sections 53 that are connected to each other by the respective flexible connecting section 54. The printed circuit board assembly 52 is therefore designed as a whole as an integral component, and plugs and connectors with connecting cables between two printed circuit board sections 53 can be omitted.

[0056] It is also preferred if the electrical and / or electronic components 51 of the control circuit 20 are arranged on the side of the printed circuit board assembly 52 facing the second mounting surface 49. Preferably, no electrical and / or electronic components 51 are present on the underside of the printed circuit board assembly 52 opposite the second mounting surface 49. This protects the components 51 in the space between the printed circuit board assembly 52 and the second support part 48, which facilitates handling during assembly.

[0057] As it is in Figure 3 As can also be seen, one or more electrical control lines 55 can lead from the control circuit 20 to one or more of the fluid control components 21, for example to the switching valve 26 and the proportional valve 28. These control lines 55 enable the control of the respective fluid control component 21 by means of the control circuit 20.

[0058] In the exemplary embodiment, the at least one electrical and / or electronic component 51 of the control circuit 20 includes the control unit 30 as well as the pressure sensors 37 of the flow detection device 32 and optionally additionally the pressure sensors for detecting the inlet pressure and / or the outlet pressure (compare Fig. 2 ).

[0059] In the exemplary embodiment, the printed circuit board assembly 52 and, for example, the component-bearing printed circuit board sections 53 are connected to the mounting surface 49 via one or more mounting pins. The mounting pins 56 are, for example, an integral part of the second support part 48 and project approximately perpendicularly from the second mounting surface 49. Each mounting pin 56 preferably has a circular cross-section and an internal thread at its free end. Mounting holes corresponding to the arrangement pattern of the mounting pins 56 may be provided in the component-bearing printed circuit board sections. The component-bearing printed circuit board sections 53 can be positioned against the free ends of the mounting pins 56 and eg They can be fastened by means of screws or other suitable fasteners, as shown schematically in Figure 3 This illustrates the point.

[0060] The first coupling surface 47 of the first support part 45 has at least one first fluid channel recess and, in the exemplary embodiment, several first fluid channel recesses 60. The fluid channel recesses 60 are formed by channel-like depressions that are recessed relative to the flat surface section 47a of the first coupling surface 47. In cross-section along their extent, the first fluid channel recesses 60 are preferably semicircular. In the exemplary embodiment, each first fluid channel recess 60 extends in a straight line. Alternatively to the preferred embodiment, one or more of the first fluid channel recesses 60 could also have an arcuate or curved shape in their direction of extension along the first coupling surface 47.

[0061] The first support section 45 also includes several first branch channels 61 extending from the first coupling surface 47 to the first mounting surface 46. In the exemplary embodiment, the first branch channels 61 each open into one of the first fluid channel recesses 60. Preferably, at least two first branch channels 61 open into each first fluid channel recess 60. A fluid connection between one or more of the fluid control components 21 and the first fluid channel recesses 60 can be established by means of the first branch channels 61.

[0062] In the second coupling surface 50 of the second support part 48, several second fluid channel recesses 62 are provided, for example. The second fluid channel recesses 62 can be configured according to the first fluid channel recesses 60 and, in the exemplary embodiment, form channel-like depressions with a preferably semicircular cross-section in their direction of extension. The second fluid channel recesses 62 are recessed relative to the flat surface section 50a of the second coupling surface 50.

[0063] In the second support part 48, second branch channels 63 can be provided, extending completely between the second mounting surface 49 and the second coupling surface 50 and opening into one or more of the second fluid channel recesses 62. In the embodiment illustrated here, all second branch channels 63 open into a single second fluid channel recess 62, each of which forms a pressure measuring channel 34 of the flow sensing device 32 or is part of the respective pressure measuring channel 34. In the embodiment illustrated here, each pressure measuring channel 34 has a section opening into the second fluid channel recess 62, which is formed by the second branch channel 63, with a further section of the pressure measuring channel 34 adjoining the second branch channel 63, which is formed within a nozzle 64.The nozzle 64 extends obliquely or at right angles from the second mounting surface 49 towards a free end 65. At this free end 65, the pressure sensor 37, which is associated with the pressure measuring channel 34, is fluidically coupled to the pressure measuring channel 34.

[0064] The arrangement of the pressure sensor in the nozzle 64 is shown schematically in Figure 9 Illustrated by example, pressure sensor 37 has a measuring element 66 that projects into the pressure measuring channel 34 and is enclosed in a ring by a radial sealing element 67. The radial sealing element 67 sits in an annular recess 68 in the region of the free end 65 of the nozzle 64. It bears against a circumferential wall of the annular recess 68 on the radial outside and against the measuring element 66 on the radial inside, thus creating a radial sealing effect. As shown in Figure 7As can be seen, all pressure sensors 37 of the flow detection device 32 are arranged on separate nozzles 64 and are preferably supported by a common component-bearing circuit board section 53.

[0065] The two support parts 45, 48 are mechanically connected to each other by their opposing coupling surfaces 47, 50, whereby the flat surface section 47a of the first coupling surface 47 can abut the flat surface section 50a of the second coupling surface 50 or can be arranged forming a gap or space. For example, the first fluid channel recesses 60 and the second fluid channel recesses 62 are selected such that each first fluid channel recess 60 and second fluid channel recess 62 form or delimit a main fluid channel 72 in the region of the parting plane or separation point between the two support parts 45, 48. Figure 8Since, for example, four first fluid channel recesses 60 and four second fluid channel recesses 62 are present, four main fluid channels 72 result.

[0066] One of these second main fluid channels 72 forms the flow measurement channel 33. As described in the Figure 4 and 6As can be seen, one of the first fluid channel recesses 60 and the associated second fluid channel recess 62 each have a section with a larger cross-section and a section with a smaller cross-section, which are connected to each other via a tapered section. These fluid channel recesses can be designated as the first measuring channel recess 73 and the second measuring channel recess 74, respectively. The two pressure measuring channels 34 of the first pressure measuring channel pair 35 and the two pressure measuring channels 34 of the second pressure measuring channel pair 36 open into the second measuring channel recess 74. For further details on the design of the flow measuring device 32, reference is made to the preceding explanations, in particular to the Figure 2 and 10 referred.

[0067] In a modification of the preferred embodiment shown here, it is also possible that a first fluid channel recess 60, together with the flat surface section 50a of the second coupling surface 50, delimits a main fluid channel 72 and / or that a second fluid channel recess 62, together with the flat surface section 47a of the first coupling surface 47, delimits a main fluid channel 72. Therefore, it is not necessary for the first and second fluid channel recesses 60 and 62 to be identical in order to form the main fluid channel 72.

[0068] A sealing arrangement 78 is provided for sealing the two support parts 45, 48 in the area of ​​the coupling surfaces 47, 50, which is shown by way of example in Figure 4This is illustrated. In the exemplary embodiment, the sealing arrangement 78 has several separate ring seals 79. In the exemplary embodiment, each ring seal 79 is inserted into a first annular groove 80 on the first coupling surface 47 of the first support part 45. The first annular groove 80 completely encloses a first fluid channel recess 60. The first annular groove 80 is dimensioned such that the inserted ring seal 79 protrudes from the first annular groove 80 and extends beyond the flat surface section 47a of the first coupling surface 47.

[0069] In the exemplary embodiment, the second coupling surface 50 also has second annular grooves 81, each of which completely encloses a second fluid channel recess 62. The second annular grooves 81 can be configured in accordance with the first annular grooves 80. When the first support part 45 and the second support part 48 are connected to each other with their opposing coupling surfaces 47, 50, each ring seal 79 sits in a first annular groove 80 and in a second annular groove 81, as shown schematically in Figure 8 This is illustrated. This ensures very good positioning of the ring seal 79 and a corresponding sealing effect.

[0070] In a modification of the preferred embodiment, at least one annular groove 80 or 81 could also be provided in only one of the support parts 45, 48 in order to seal a main fluid channel 72 formed after the support parts 45, 48 are joined. In a further modification, a plate-shaped sealing element could be arranged between the two support parts 45, 48, which has corresponding recesses or openings in the area of ​​the first fluid channel recesses 60 and the second fluid channel recesses 62 and bears against the flat surface sections 47a, 50a of the coupling surfaces 47, 50 around the first fluid channel recesses 60 and the second fluid channel recesses 62.

[0071] In another embodiment, the sealing arrangement 78 can also be connected to one of the support parts by a material-bonded or adhesive bond. For example, the sealing arrangement 78 can be glued to one of the coupling surfaces 47, 50 or attached to the support parts 45, 48 by a two-component injection molding process during their manufacture.

[0072] In a preferred embodiment, the support parts 45, 48 are made of a transparent material, at least in the area of ​​their coupling surfaces 47, 50, or alternatively, entirely. This allows a visual inspection in the assembled, mounted state to verify that the ring seals 79 are correctly positioned in their respective annular grooves 80 and 81 and that the sealing effect is ensured.

[0073] A further, independent aspect of the fluid control arrangement 12 according to the invention relates to the manufacture of the support parts 45, 48. Preferably, the support parts 45, 48 are designed as injection-molded parts. The mold closing direction is preferably selected such that it coincides with the extension direction of the branch channels 61, 63. In injection molding, the mold closing direction is the direction in which the two injection-molded parts are moved relative to each other to close or open the injection mold.

[0074] Each branch channel 61, 63 of a carrier part 45, 48 is designed without undercuts in one direction from one end to the other. In this direction, the branch channel 61, 63 may be conically tapered. Each first branch channel 61 extends either without undercuts from the first mounting surface 46 to the first coupling surface 47 or vice versa from the first coupling surface 47 to the first mounting surface 46. Similarly, each second branch channel 63 extends without undercuts from the first coupling surface 50 to the first mounting surface 49 or to the free end of the nozzle 64 or vice versa from the free end of the nozzle 64 or from the second mounting surface 49 to the second coupling surface 50. Due to this undercut-free design of the branch channels 61, 63, the carrier part 45, 48 can be very easily manufactured as an injection-molded part.

[0075] The invention relates to a fluid control arrangement 12 for a medical device 10, in particular a medical device for argon plasma coagulation. The fluid control arrangement 12 has a fluid control circuit 19 with at least one fluid-flowing fluid control component 21. A control circuit 20 with at least one electrical and / or electronic component 51 is provided for controlling the at least one fluid control component 21. A first support part 45 has a first coupling surface 47 and a second support part 48 has a second coupling surface 50. In the first coupling surface 47, at least one first fluid channel recess 60 and / or in the second coupling surface 47, at least one second fluid channel recess 62 is provided. When the coupling surfaces 47 and 50 of the support parts 45 and 48 facing each other are connected, at least one main fluid channel 72 is formed in the region of the separation point.Each main fluid channel 72 is thus partially bounded by the first support part 45 and partially by the second support part 48. A first mounting surface 46 for the at least one fluid control component 21 can be provided on the first support part 45. A second mounting surface 49 for the at least one electrical and / or electronic component 51 of the control circuit 20 can be provided on the second support part 48. In addition to or as an alternative to mounting components on the mounting surfaces 46, 49, the support parts 45, 48 can be designed as injection-molded parts. A further independent aspect concerns the hydraulic circuit in the fluid control circuit 19, wherein a flow sensing device 32 is arranged upstream of an actuator, via which the fluid flow from an output port 24 of the fluid control arrangement 12 can be controlled or regulated by the control circuit 20. Reference symbol list:

[0076] 10 Medical device 11 Fluid source 12 Fluid control arrangement 13 Instrument 14 High-voltage source 15 Electrode 19 Fluid control circuit 20 Control circuit 21 Fluid control component 22 Fluid channel arrangement 23 Input connection 24 Output connection 26 Switching valve 27 Pressure regulating valve 28 Proportional valve 29 Filter 30 Control unit 31 Sensor units 32 Flow sensing device 33 Flow measuring channel 33a First channel section 33b Second channel section 33c Connecting channel section 34 Pressure measuring channel 35 First pressure measuring channel pair 36 Second pressure measuring channel pair 37 Pressure sensor 38 Measuring orifice 45 First support part 46 First mounting surface 47 First coupling surface 47a Flat surface section of the first coupling surface 48 Second support part 49 Second mounting surface 50 Second coupling surface 50a Flat surface section of the second coupling surface 51 Electrical and / or electronic component 52 Printed circuit board arrangement 53 Component-bearing printed circuit board section 54 Flexible connecting section 55 Control line 56 Mounting pin 60 First fluid channel recess 61 First branch channel 62 Second fluid channel recess 63 Second branch channel 64 Nozzle 65 Free end of nozzle 66 Measuring element 67 Radial sealing element 68 Ring recess 72Hauptfluidkanal 73erste Messkanalaussparung 74zweite Messkanalaussparung 78Dichtungsanordnung 79Ringdichtung 80erste Ringnut 81zweite Ringnut EEingangssignal FStrömungsrichtung SSteuersignal

Claims

1. Fluid control arrangement (12) for a medical device (10) with a fluid control circuit (19) comprising at least one fluid channel arrangement (22) and at least one fluid control component (21) that are arranged between an inlet connection (23) and an outlet connection (24), with a control circuitry (20) comprising at least one electric and / or electronic component (51), the control circuitry (20) being configured to control the at least one fluid control component (21) of the fluid control circuit (19), characterized in that a main fluid channel (72) of the fluid channel arrangement (22) forms a flow measurement channel (33) of a flow measurement device (32), that a first pressure measurement channel pair (35) and a second pressure measurement channel pair (36) are provided, wherein each pressure measurement channel pair (35, 36) has two pressure measurement channels (34), which connect with the flow measurement channel (33) at locations distant to each other in flow direction, that the pressure measurement channels (34) of the first pressure measurement channel pair (35) open into a first channel section (33a) of the flow measurement channel (33) having a first flow cross-section and that the pressure measurement channels (34) of the second pressure measurement channel pair (36) open into a second channel section (33b) of the flow measurement channel (33) having a second flow cross-section, wherein the first and the second flow cross-sections have different areas.

2. Fluid control arrangement according to claim 1, characterized in that a separate pressure sensor (37) is connected to each of the pressure measurement channels (34) or that a difference pressure sensor is connected to the pressure measurement channels (34) of one pressure measurement channel pair (35, 36).

3. Fluid control arrangement according to claim 1 or 2, characterized in that at least two of the pressure values measured by the pressure sensors (37) are transmitted to control unit (30) or an evaluation unit of the control circuitry (20) that is configured to determine a mass or volume flow of the fluid flow through the flow measurement channel (33) from the at least two pressure values.

4. Fluid control arrangement according to any of the preceding claims, characterized in that the fluid control circuit (19) comprises a series connection of an actuator and the flow measurement device (32), wherein in flow direction (F) the flow measurement device (32) is arranged before the actuator.

5. Fluid control arrangement according to claim 4, characterized in that in flow direction (F) the flow measurement device (32) is arranged between a pressure limiting device or a pressure control device or a pressure regulation device and the actuator.

6. Fluid control arrangement according to any of the preceding claims, having a first carrier part (45) comprising a first mounting surface (46) and a first coupling surface (47) and with a second carrier part (48) comprising a second mounting surface (49) and a second coupling surface (50), wherein the at least one fluid control component (21) of the fluid control circuit (19) and the at least one electric and / or electronic component (51) of the control circuitry (20) are arranged at the mounting surfaces (46, 49) of the carrier parts (45, 48), wherein at least one first fluid channel cavity (60) is provided in the first coupling surface (47) and / or at least one second fluid channel cavity (62) is provided in the second coupling surface (50) and wherein the two carrier parts (45, 48) are connected with each other at the coupling surfaces (47, 50) such that the at least one fluid channel cavity (60) and / or the at least one second fluid channel cavity (62) limit at least one main fluid channel (72) of the fluid channel arrangement (22).

7. Fluid control arrangement according to claim 6, characterized in that at least one first fluid channel cavity (60) as well as at least one second fluid channel cavity (62) are provided, wherein each of the first fluid channel cavities (60) and one associated second fluid channel cavity (62) form one main fluid channel (72) of the fluid channel arrangement (22).

8. Fluid control arrangement according to claim 7, characterized in that each first fluid channel cavity (60), as well as each second fluid channel cavity (62) has a semicircle cross-section.

9. Fluid control arrangement according to any of the claims 6 to 8, characterized in that the first carrier part (45) and the second carrier part (48) are formed by a respective injection mold part.

10. Fluid control arrangement according to any of the claims 6 to 9, characterized in that in the first carrier part (45) at least one fluidic first branch channel (61) is present that extends between the first mounting surface (46) and the first coupling surface (47) and is free of undercuts in at least one extension direction from the first mounting surface (46) to the first coupling surface (47) or from the first coupling surface (47) to the first mounting surface (46).

11. Fluid control arrangement according to any of the claims 6 to 10, characterized in that in the second carrier part (48) at least one fluidic second branch channel (63) is present that extends between the second mounting surface (49) and the second coupling surface (50) and is free of undercuts in at least one extension direction from the second mounting surface (49) to the second coupling surface (50) or from the second coupling surface (50) to the second mounting surface (49).

12. Fluid control arrangement according to any of the claims 6 to 11, characterized in that one or more first fluid channel cavities (60) and / or one or more second fluid channel cavities (62) form multiple main fluid channels (72) that are separated in or along the coupling surfaces (47, 50) from each other.

13. Fluid control arrangement according to any of the claims 6 to 12, characterized in that each fluid control component (21) is arranged at the first mounting surface (46).

14. Fluid control arrangement according to any of the claims 6 to 13, characterized in that each electric and / or electronic component (51) is arranged at the second mounting surface (49).