Fluid control devices for medical devices

Abstract

To provide a fluid control arrangement with a compact and inexpensive configuration.SOLUTION: The invention relates to a fluid control arrangement (12) for a medical device (10), particularly a medical device for argon plasma coagulation. The fluid control arrangement (12) has a fluid control circuit (19) with at least one fluid control component (21), through which a fluid flows. For controlling the fluid control component (21), a control circuit (20) with at least one electric and / or electronic component (51) is provided. A main fluid channel (72) of a fluid channel part (22) forms a flow measurement channel (33) of a flow measuring instrument (32). At least one pressure measurement channel pair (35 or 36) with two pressure measurement channels (34) is provided, the pressure measurement channels (34) of the pressure measurement channel pair connect with the flow measurement channel (33) at locations distant from each other in a flow direction (F).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a fluid control device for a medical device, which can be used to control or feedback control the volumetric or mass flow rate of a fluid, in particular a medical gas. [Background technology]

[0002] Devices for fluid control are known in various technical fields. Patent document 1 describes a small device of foldable connected metal plates, each with a flow channel cavity etched inside. By folding, a multi-layer body is formed to conduct fluids. This device is suitable for analytical equipment, e.g., chromatographs, due to its miniaturization.

[0003] Patent Document 2 discloses a method and device for sample extraction with integrated analytical chemical sensor measurement, as well as a method for manufacturing the device. The measurement cartridge includes a chemical or biosensor and can be placed between a needle and a syringe via a luer connection. After sample extraction, the measurement cartridge can be inserted into a manual measurement device using the syringe.

[0004] A flow measurement device is known from US Pat. No. 5,623,999, which comprises a flow sensor arranged in a channel section of a flow passage with a reduced diameter. A vortex generator and a pressure measurement channel are arranged downstream. The frequency of the generated vortices is a function of the flow velocity, which can be detected via the pressure measurement channel.

[0005] US Pat. No. 5,649,493 discloses an apparatus and method for detecting flow rate as a function of the pressure difference between two contact points in a flow path. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] U.S. Patent No. 5,888,390 [Patent Document 2] DE 19546535 [Patent Document 3] U.S. Patent No. 5,020,373 [Patent Document 4] International Publication No. 99 / 36747 Summary of the Invention [Problem to be solved by the invention]

[0007] It is considered an object of the present invention to provide an improved fluid control device for medical equipment over the prior art. In particular, the fluid control device is configured to control the gas flow rate of medical gases and, in doing so, achieve a compact and inexpensive configuration. [Means for solving the problem]

[0008] This object is solved by a fluid control device according to the features of claim 1.

[0009] In particular, the fluid control device is configured to control or feedback control the flow of a gas, such as argon, oxygen, carbon dioxide, or other gas used in the medical device. In other medical applications, a liquid flow can be controlled or feedback controlled instead of a gas flow. The medical device may in particular be an instrument for argon plasma coagulation.

[0010] The fluid control device has a fluid control circuit including a flow path section and at least one fluid control component. The flow path section and the fluid control component are disposed between an inlet point and an outlet point and together form a fluid connection between the inlet point and the outlet point. During operation of the fluid control device, a fluid preferably flows through at least one or all of the fluid control components. The fluid control component may be, for example, a directional valve, a proportional valve, a pressure control or pressure regulating valve, a filter, or other component that not only allows a fluid to flow and passes the fluid, but also changes the fluid properties (pressure, volumetric flow rate, mass flow rate, purity, etc.) of the flowing fluid.

[0011] The control circuit is configured to control at least one fluid control component of the fluid control circuit. To this end, the control circuit comprises at least one electric and / or electronic component, e.g., a controller, which outputs a control signal to 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, e.g., a pressure sensor, may be in contact with the fluid, but preferably do not have fluid flow therethrough.

[0012] The fluid control device preferably comprises a first carrier part having a first mounting surface and a first coupling surface, and a second carrier part having a second mounting surface and a second coupling surface. The mounting surface and the coupling surface of each carrier part are preferably arranged on opposite sides of the carrier part. In an embodiment, the first mounting surface and / or the second mounting surface extend in a respective plane. The first mounting surface is configured for mounting at least one fluid control component. The second mounting surface is configured for mounting 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 carrier part, and / or one or more components of the control circuit are arranged on the second mounting surface of the second carrier part. Preferably, 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 surfaces.

[0013] In an embodiment, some or all of the fluid control components provided are disposed directly on the first mounting surface and are fluidly connected to the flow path portion. A circuit board portion supporting at least one electrical and / or electronic component of the control circuit may be mounted on the second mounting surface. Preferably, all electrical and / or electronic components of the control circuit are disposed on the circuit board portion.

[0014] It is also advantageous if no components are attached to the first carrier part and / or the second carrier part other than the respective mounting surfaces.

[0015] To create at least one main flow path of the flow path section, at least one first flow path cavity may be provided in the first joining surface and / or at least one second flow path cavity may be provided in the second joining surface. Therefore, the at least one main flow path may extend along a separation plane between the first and second joining surfaces. In the circumferential direction, the at least one main flow path may be defined partly by the first joining surface and partly by the second joining surface. The first and second carrier parts may be connected to each other in the region of the first and second joining surfaces. The joining surfaces preferably have flat surface portions that can be in direct two-dimensional contact or that face each other when a gap is created. These flat surface portions surround the flow path cavity of the carrier part. At least one of the first and second flow path cavities is recessed compared to the peripheral surface portions of the first and second joining surfaces. When the two carrier parts are connected to each other in the bonding surface region, the first flow path cavity together with the second carrier part and / or the second flow path cavity together with the first carrier part defines a main flow path in the region of the separation position between the two carrier parts, and optionally when using sealing parts, the carrier parts are connected to each other in the bonding surface region such that at least one main flow path is fluidically sealed in the region of the separation position between the two carrier parts.

[0016] At least one main flow path may be present exclusively in the region of the separation position or separation surface between the carrier parts, in particular being defined by both carrier parts along its entire length. In particular, the at least one main flow path is defined simultaneously along its entire length by a channel wall of the first carrier part and by a channel wall of the second carrier part. Additional flow paths of the flow path parts may extend into the first and / or second carrier part, in particular forming branches from or to the flow path cavities. Preferably, all flow paths of the flow path parts are defined by channel walls that are an integral part of the first or second carrier part. Preferably, no fluid connection is formed in the fluid control circuit between the inlet and outlet points to another line that extends completely outside the carrier parts, for example a direct line between two fluid control components.

[0017] Preferably, each main flow channel is formed by a first flow channel cavity in the first carrier part and a second flow channel cavity in the second carrier part. Preferably, each first flow channel cavity and / or second flow channel cavity has a semicircular cross section, so that when connections are made between the carrier parts, each main flow channel has a circular cross section. Preferably, at least some of the main flow channels have a substantially circular cross section.

[0018] The flow path portion may include at least one branch path branching from the main flow path. For example, the first carrier portion may have at least one branch path extending between the first mounting surface and the first coupling surface. Accordingly, the second carrier portion may have at least one second branch path extending between the second mounting surface and the second coupling surface.

[0019] It is particularly advantageous to manufacture the carrier parts by forming the first carrier part and the second carrier part, respectively, by injection-molded parts. The injection-molded parts are preferably manufactured from a uniform material, in particular from a plastic or composite. In this way, the first carrier part and the second carrier part are formed as a single carrier part without seams or connection locations. In particular, after manufacturing the carrier parts, there is no need for rework to remove material to form the flow channels. It is preferable that all of the flow channels of the flow channel parts are formed by manufacturing the carrier parts during their manufacture.

[0020] If the first carrier part has at least one first branch, the at least one first branch is free of undercuts, at least in the direction of extension from the first mounting surface to the first coupling surface, or vice versa. The at least one first branch may be conical or cylindrical. If the second carrier part has at least one second branch, the at least one second branch is free of undercuts, at least in the direction of extension from the second mounting surface to the second coupling surface, or vice versa. The at least one second branch may be conical or cylindrical. In this way, the step of manufacturing the carrier part as an injection-molded part is significantly simplified.

[0021] Preferably, all cutouts extending transversely to the mounting and coupling surfaces are free from undercuts, at least in the direction from the respective coupling surface to the respective mounting surface or vice versa. The at least one first branch and / or the at least one second branch extend in particular in the closing direction of an injection mold for producing the first or second carrier part as an injection-molded part.

[0022] The step of manufacturing the carrier part as an injection-molded part and / or the at least one branch channel configuration without undercuts as described above are independent aspects of the invention and can be provided regardless of whether or not fluid control components of the fluid control circuit and / or components of the control circuit are arranged on a mounting surface.

[0023] A sealing element for sealing at least one main flow channel is preferably arranged between the first and second joining surfaces. The sealing element may comprise a ring seal for each main flow channel present. If a plurality of separate main flow channels are formed in the region of the separation surface or separation position between the carrier parts, each main flow channel is preferably completely surrounded by a ring seal of the sealing element in order to seal the main flow channel from the surrounding environment. To this end, a ring groove for inserting the ring seal may be present in the first and / or second joining surface. The ring groove may completely surround the first flow channel cavity in the first joining surface, and the ring groove may completely surround the second flow channel cavity in the second joining surface.

[0024] It is further advantageous if the first carrier part and / or the second carrier part are at least partly made of a transparent material, so that when the connection between the carrier parts is made, it is possible to determine by visual inspection from the outside whether the seals are in the correct position in the region of the separation position between the two carrier parts, in particular whether the at least one ring seal is correctly positioned in each ring groove.

[0025] Preferably, all fluid control components of the fluid control circuit are located on the first mounting surface, in particular directly on the first mounting surface. Additionally or alternatively, all electrical and / or electronic components of the control circuit are located indirectly or directly on the second mounting surface, preferably indirectly using a circuit board portion. Preferably, fluid does not flow through any of the components of the control circuit.

[0026] In the present invention, the main flow path of the flow path section forms a flow measurement channel. The flow measurement channel is part of a flow measuring device of the fluid control device. Preferably, the flow measurement channel has a substantially circular cross section along its entire length. At least one pressure measurement channel pair is provided, having two pressure measurement channels, the pressure measurement channels of the pressure measurement channel pair connecting with the flow measurement channel at positions spaced apart from each other in the flow direction. The pressure measurement channels of the pressure measurement channel pair are preferably located in the same carrier section, but may alternatively be located in different carrier sections. Preferably, the pressure measurement channels extend at least partially into and through the second carrier section. In a preferred embodiment, a separate pressure sensor is assigned to each pressure measurement channel. The pressure sensors are configured to measure pressure within the pressure measurement channel at a connection position between each pressure measurement channel and the flow measurement channel. In an alternative configuration, a differential pressure sensor is connected to the pressure measurement channels of the pressure measurement channel pair, so that one differential pressure sensor per pressure measurement channel pair is sufficient. The differential pressure sensor is configured to generate a differential pressure signal and transmit it to the control section.

[0027] As mentioned above, at least a portion of each pressure measurement channel may be formed by a branching channel, and in preferred embodiments, a further portion of each pressure measurement channel may extend beyond the mounting surface, in particular into a nozzle formed integrally with the respective carrier part.

[0028] It is also advantageous to provide a first pressure measurement channel pair and a second pressure measurement channel pair, in which the pressure channels are connected to the same flow measurement channel. The flow measurement channel preferably has a first channel portion with a first flow cross-section and a second channel portion with a second flow cross-section, the two flow cross-sections being different from each other, in particular, different in size. The pressure measurement channel of the first pressure measurement channel pair is connected to the first channel portion, and the pressure measurement channel of the second pressure measurement channel pair is connected to the second channel portion. This configuration provides the possibility of measuring flow rates using each pressure measurement channel pair, and the different flow cross-sections allow different measurement ranges for determining the volumetric or mass flow rate of the fluid flow. In this way, the total measurement range provided is increased.

[0029] Preferably, an evaluation unit of the control circuit is provided to which the measured pressure values ​​of at least one pressure measurement channel pair are transmitted in order to determine the volumetric or mass flow rate of the fluid flowing through the flow measurement channels. Pipe friction in the flow measurement channels generates a pressure difference between the pressure measurement channels of a common pressure measurement channel pair, where the pressure difference is characteristic for the volumetric or mass flow rate of the fluid flowing through the flow measurement channels, so that the volumetric or mass flow rate can be determined in the evaluation unit.

[0030] The above-described configurations of the flow measurement device, in particular the flow measurement channel and / or the pressure measurement channel and / or the connected pressure sensor, may be implemented in addition to or instead of other aspects of the invention.

[0031] The fluid control circuit preferably also comprises a series connection of an actuator, in particular a proportional valve, and a flow meter. The flow meter can preferably be configured as described above. In the flow direction, the flow meter is preferably arranged before the actuator. This ensures measurement independent of a load, e.g., a surgical instrument, connected to the outlet.

[0032] Furthermore, it is advantageous if the flow measuring device is arranged in the flow direction between the pressure limiting device or pressure control device or pressure regulator and the actuator, and preferably no further fluid control components, in particular fluid pressure-changing fluid control components that are not part of the flow measuring device, are present between the pressure limiting device or pressure control device or pressure regulator and the actuator.

[0033] The circuit configuration of the fluid control circuit with respect to the hydraulic connection diagram, in particular the arrangement of the flow meter in series with further fluid control components, can be used independently of or in addition to the above-mentioned features of the fluid control device, in particular whether the fluid control circuit and / or components of the control circuit are located on the mounting surface of the carrier part.

[0034] Preferred embodiments of the invention can be derived from the dependent claims and the drawings. Preferred embodiments of the invention will now be described in detail with reference to the accompanying drawings. [Brief explanation of the drawings]

[0035] [Figure 1] FIG. 1 is a block diagram of an embodiment of a medical device in the form of an argon plasma coagulator. [Figure 2] FIG. 2 is a hydraulic block diagram of an embodiment of a fluid control circuit for the device of FIG. [Figure 3] FIG. 3 is a schematic basic diagram of an embodiment of a fluid control device comprising a fluid control circuit and a control circuit arranged on a carrier part. [Figure 4] FIG. 4 is a schematic diagram of an embodiment of a first carrier part in plan view on a first coupling surface of the first carrier part and a schematic diagram of an embodiment of a sealing part. [Figure 5] 5 is the first carrier part of FIG. 4 in a cross section taken along the section line VV of FIG. [Figure 6] FIG. 6 is a schematic illustration of an embodiment of a second carrier part in plan view on the second coupling surface of the second carrier part. [Figure 7]7 is a schematic side view of the second carrier portion according to FIG. 6, seen from the side indicated by the arrow VII in FIG. [Figure 8] FIG. 8 is a schematic cut-away view through the carrier parts of the fluid control device according to FIG. 3 connected together. [Figure 9] FIG. 9 is a basic diagram of the structure of a pressure sensor in a control circuit. [Figure 10] FIG. 10 is a basic diagram of an embodiment of a flow rate measuring device for a fluid control device. DETAILED DESCRIPTION OF THE INVENTION

[0036] 1 illustrates a medical device 10 configured as an argon plasma coagulation device, by way of example. The medical device 10 includes a fluid source 11 to which a fluid control device 12 is fluidly connected. An instrument 13 may be connected to the fluid control device 12, which provides a channel for the flow of fluid output by the fluid control device 12. The illustrated embodiment of the medical device 10 further includes a high voltage source 14 for providing a high voltage to the instrument 13. The instrument 13 may be electrically connected to the high voltage source 14.

[0037] In an embodiment, fluid control device 12 outputs a flow of argon gas for instrument 13, which flows around electrode 15 at the outlet end of instrument 13. A high voltage may be applied to electrode 15 for argon plasma coagulation.

[0038] 1 is merely an example, and the inventive fluid control device 12 may also be used in other medical devices 10.

[0039] The fluid control device 12 includes a fluid control circuit 19 and a control circuit 20. The fluid control circuit 19 includes at least one, and in some embodiments, a plurality of, fluid control components 21 fluidly connected to a flow path portion 22 of the fluid control circuit 19. The flow path portion 22 and the fluid control components 21 provide a fluid connection between an inlet point 23 and an outlet point 24 of the fluid control device 12 or the fluid control circuit 19. The fluid source 11 may be fluidly connected to the inlet point 23. The device 13 may be fluidly connected to the outlet point 24.

[0040] The fluid flows through fluid control components 21. In an embodiment, fluid control circuit 19 includes a switching valve 26, a pressure regulator valve 27, and a proportional valve 28 as an actuator. Optionally, fluid control circuit 19 may also include a filter 29. Preferably, filter 29 is located immediately adjacent to and downstream of inlet point 23.

[0041] In an embodiment, the control circuit 20 comprises a control unit 30 that outputs at least one control signal S to at least one controllable fluid control component 21. According to this example, at least the switching valve 26 and the proportional valve 28 may each be controlled by the control signal S of the control unit 30. At least one input signal E may be transmitted to the control unit 30. The at least one input signal E may be, for example, a sensor signal or a measurement signal. In the embodiment shown in FIG. 2, there are multiple sensor units 31 that provide different input signals E in the form of sensor signals. For example, the inlet pressure adjacent to the inlet point 23 or the filter 29 and the outlet pressure at the outlet point 24 may be detected by respective pressure sensors and transmitted to the control unit 30.

[0042] In an embodiment, the fluid control device 12 also comprises a flow detector 32 for detecting a volumetric or mass flow rate or a signal characterizing the volumetric or mass flow rate along a flow measurement channel 33 of the flow path section 22. According to the hydraulic scheme of Fig. 2, the fluid control circuit 19 comprises a circuit configuration in which the flow detector 32 is arranged upstream of a proportional valve 28. The proportional valve 28, which forms an actuator for controlling the mass or volumetric flow rate for the instrument 13, is preferably arranged immediately upstream of the outlet point 24. According to this example, a pressure regulating valve 27 is arranged upstream of the flow detector 32 so that a predetermined fluid pressure is applied at the inlet of the flow measurement channel 33 upstream of the flow detector 32. A switching valve 26 is arranged upstream of the pressure regulating valve 27, which can block or disable the fluid flow.

[0043] In an embodiment, the flow detector 32 comprises two sensor units 31 that detect a pressure difference between two separate measurement locations in the flow measurement channel 33 and transmit the pressure difference to the control unit 30. Based on the pressure difference, the control unit 30 may determine a volumetric or mass flow measurement of the fluid flowing through the flow measurement channel 33. According to this example, the measurement locations of the two sensor units 31 are located in channel sections with different flow cross sections. This allows the total measurement range for determining the mass or volumetric flow rate to be increased.

[0044] An embodiment of the flow detector 32 is diagrammatically illustrated in FIG. 10. The flow measurement channel 33 comprises a first channel portion 33a, a second channel portion 33b, and a connecting channel portion 33c arranged therebetween. In the direction F of fluid flow, the first channel portion 33a, the connecting channel portion 33c, and the second channel portion 33b are arranged in series. The first channel portion 33a has a larger flow cross-section than the second channel portion 33b. In the region of the connecting channel portion 33c, the flow cross-section of the flow measurement channel 33 is smaller. The cross-sectional outline of the flow measurement channel 33 is preferably approximately circular.

[0045] In the first channel portion 33a, the two pressure measurement channels 34 of the first pressure measurement channel pair 35 communicate outwardly and apart from each other in the flow direction F. In the second channel portion 33b of the flow measurement channel 33, the two pressure measurement channels 34 of the second pressure measurement channel pair 36 communicate outwardly and apart from each other in the flow direction F. In each of the channel portions 33a, 33b, the flow cross-section of the flow measurement channel 33 is constant. Fluid friction during flow along the flow measurement channel 33 causes a pressure loss between the pressure measurement channels 34 of each pressure measurement channel pair 35, 36. A pressure sensor 37 is connected to each pressure measurement channel 34, and each pressure sensor 37 generates a pressure signal corresponding to the fluid pressure at the position where the pressure measurement channel 34 connects to the flow measurement channel 33. Each pressure sensor 37 outputs the pressure signal to the control unit 30. In this embodiment, each measurement opening 38 is formed by the channel wall of each channel portion 33a between the connection positions of the pressure channels 34 of the common pressure measurement channel pair 35 or 36. In the control unit 30, the mass flow rate value or volume flow rate value for the fluid flowing through the flow measurement channel 33 may be determined from two pressure signals, in particular two pressure signals of pressure sensors 37 that are part of a common pressure measurement channel pair 35 or 36.

[0046] It is also possible to connect a differential pressure sensor to the pressure measurement channel 34 for one 35 or 36 or all of the pressure measurement channel pairs.

[0047] The hydraulic configuration of the fluid control components 21 in the fluid control circuit 19 for the flow direction F described above is an aspect of the invention that can be realized independently of further aspects described below. Due to the arrangement of the flow detector 32 upstream of the proportional valve 28 forming the actuator, the measurement of the volumetric or mass flow rate can be performed independently of the load according to the example formed by the instrument 13. The adjustment of the proportional valve 28 is known in the control unit 30, since it is determined by a control signal S of the control unit 30. The adjustment may be taken into account, if necessary, during the determination of the volumetric or mass flow rate value.

[0048] Further, additional or alternative aspects of the inventive fluid control device 12 relate to the compact and simple construction and / or manufacture and / or assembly of the fluid control device 12. These inventive aspects are described below with reference to Figures 3-9.

[0049] FIG. 3 shows a schematic representation of an embodiment of the mechanical structure of the fluid control device 12. In this embodiment, the fluid control device 12 comprises a first carrier part 45 having a first mounting surface 46 and a first coupling surface 47, and a second carrier part 48 having 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. In particular, the fluid control component 21 may be directly attached to the first mounting surface, as shown in FIG. 3. In this example, the first mounting surface and the first coupling surface 47 are located on the front and back of the first carrier part 45. Accordingly, the second mounting surface 49 and the second coupling surface 50 are also located on the front and back of the second carrier part 48.

[0050] The first mounting surface 46 and / or the second mounting surface 49 preferably extend in a plane. In this embodiment, the first coupling surface 47 has in particular an uninterrupted flat surface portion 47a extending in a plane that is preferably oriented parallel to the plane in which the first mounting surface 46 extends. In this embodiment, the second coupling surface 50 has in particular an uninterrupted flat surface portion 50a extending in a plane that is preferably oriented parallel to the plane in which the second mounting surface 49 extends. The carrier parts 45, 48 may, for example, be plate-shaped or cubic-shaped.

[0051] The mating surfaces 47, 50 are configured to establish a connection between the two carrier parts 45, 48, and the flat surface portions 47a, 50a of the mating surfaces 47, 50 may abut each other or may be positioned facing each other when a gap is formed.

[0052] For example, second mounting surface 49 is configured to support at least one electrical and / or electronic component of control circuit 20. As shown in FIG. 3 , a plurality of, preferably all, electrical and / or electronic components 51 of control circuit 20 are disposed on circuit board portion 52 attached to second mounting surface 49. Circuit board portion 52 includes a plurality of component-supporting circuit board portions 53 electrically and mechanically connected to one another via flexible connecting portions 54. Flexible connecting portions 54 are integral with two component-supporting circuit board portions 53 connected to one another by each flexible connecting portion 54. In this way, circuit board portion 52 is integrally formed as a whole, thereby avoiding the need for plugs and plug connections with connecting cables between circuit board portions 53.

[0053] Furthermore, it is preferable that the electric and / or electronic components 51 of the control circuit 20 are arranged on the side facing the second mounting surface 49 of the circuit board part 52. It is preferable that there are no electric and / or electronic components 51 on the underside of the circuit board part 52 opposite the second mounting surface 49. In this way, the components 51 are arranged so as to be protected in the gap between the circuit board part 52 and the second carrier part 48, which simplifies handling during assembly.

[0054] 3, one or more electrical control wires 55 may run from the control circuit 20 to one or more fluid control components 21, in this example, the switching valve 26 and the proportional valve 28. These control wires 55 facilitate control of each of the fluid control components 21 using the control circuit 20.

[0055] In an embodiment, the control unit 30 and the pressure sensor 37 of the flow detector 32, and optionally an additional pressure sensor for detecting the inlet pressure and / or outlet pressure (compare Figure 2), are part of at least one electrical and / or electronic component 51 of the control circuit 20.

[0056] The circuit board portion 52, and in this example, the component-supporting circuit board portion 53, are connected to the mounting surface 49 via one or more mounting pins 56 according to this example. In this example, the mounting pins 56 are an integral part of the second carrier portion 48 and extend generally perpendicularly from the second mounting surface 49. Preferably, each mounting pin 56 has a circular cross section and may have internal threads at its free end. The component supporting the circuit board portion may have mounting holes corresponding to the arrangement pattern of the mounting pins 56. The component-supporting circuit board portion 53 may contact the free ends of the mounting pins 56 and may be attached using screws or other suitable attachment means, as shown schematically in FIG. 3.

[0057] The first bonding surface 47 of the first carrier part 45 has at least one first flow path cavity 60, and in this embodiment, multiple first flow path cavities 60. The first flow path cavities 60 are formed by groove-like recesses dug from the flat surface portion 47a of the first bonding surface 47. In a cross section perpendicular to the extension direction, the first flow path cavities 60 preferably have a semicircular shape. In this embodiment, each flow path cavity 60 extends linearly. Alternatively, in the preferred embodiment, one or more first flow path cavities 60 may be arc-shaped or curved in the extension direction along the first bonding surface 47.

[0058] The first carrier part 45 further includes a plurality of first branch passages 61 extending from the first coupling surface 47 to the first mounting surface 46. In an embodiment, each of the first branch passages 61 leads to one of the first flow path cavities 60. Preferably, at least two first branch passages 61 lead to each first flow path cavities 60. The first branch passages 61 allow for establishing a fluid connection between one or more fluid control components 21 and the first flow path cavities 60.

[0059] In the second bonding surface 50 of the second carrier part 48, there are, according to the present example, a plurality of second flow passage cavities 62. The second flow passage cavities 62 may be configured in accordance with the first flow passage cavities 60, and preferably in accordance with the present example, in a groove-like recess having a semicircular cross section perpendicular to the extension direction. The second flow passage cavities 62 are recessed below the flat surface portion 50a of the second bonding surface 50.

[0060] The second carrier part 48 has second branches 63 which extend completely between the second mounting surface 49 and the second coupling surface 50 and which lead to one or more second flow cavity 62. In the illustrated embodiment, all second branches 63 lead to one single second flow cavity 62, and two second branches 63 each form or are part of a pressure measurement channel 34 of the flow detector 32. In the illustrated embodiment, each pressure measurement channel 34 formed by the second branches 63 has a portion which leads to the second flow cavity 62. A further portion of the pressure measurement channel 34 abuts the second branches 63 formed in a nozzle 64. The nozzle 64 extends obliquely or orthogonally from the second mounting surface 49 to a free end 65 at which the pressure sensor 37 assigned to the pressure measurement channel 34 is fluidly coupled to the pressure measurement channel 34.

[0061] The arrangement of the pressure sensors in the nozzle 64 is diagrammatically illustrated in Figure 9. According to this example, the pressure sensor 37 comprises a measuring member 66 which extends into the pressure measurement channel 34 and is surrounded in an annular manner by a radial sealing member 67. The radial sealing member 67 is mounted in a ring cavity 68 in the region of the free end 65 of the nozzle 64. The radial sealing member 67 is supported radially outwardly by the peripheral wall of the ring cavity 68 and radially inwardly by the measuring member 66, thus creating a radial sealing effect. As can be seen in Figure 7, all pressure sensors 37 of the flow detector 32 are each arranged in a separate nozzle 64 and are preferably supported on a common component support circuit board part 53.

[0062] The two carrier parts 45, 48 are mechanically connected to each other with their joining surfaces 47, 50 facing each other, and the flat surface portion 47a of the first joining surface 47 may abut the flat surface portion 50a of the second joining surface 50, or may be arranged to form a gap or clearance. According to this example, the first flow path cavities 60 and the second flow path cavities 62 are selected so that each first flow path cavity 60, together with one second flow path cavity 62, forms or defines one main flow path 72 in the region of the separation surface or separation position between the two carrier parts 45, 48 (FIG. 8). According to this example, four first flow path cavities and four second flow path cavities 62 are provided, and therefore four main flow paths 72 are obtained.

[0063] One of these main flow paths 72 serves as the flow measurement channel 33. As can be seen in FIGS. 4 and 6, one of the first flow path cavities 60 and its associated second flow path cavity 62 comprises a larger cross-sectional area and a smaller cross-sectional area connected to each other by a tapered section. The flow path cavities may be designated as first measurement channel cavities 73 and second measurement channel cavities 74. The two pressure measurement channels 34 of the first pressure measurement channel pair 35 and the two pressure measurement channels 34 of the second pressure measurement channel pair 36 communicate with the second measurement channel cavity 74. For further configuration of the flow detector 32, see the above description, and in particular FIGS. 2 and 10.

[0064] In variations on the preferred embodiment shown, the first flow path cavity 60 can define the main flow path 72 together with the flat surface portion 50a of the second bonding surface 50, and / or the second flow path cavity 62 can define the main flow path 72 together with the flat surface portion 47a of the first bonding surface 47. In this manner, there need not be coincident first and second flow path cavities 60, 62 to form the main flow path 72.

[0065] To seal the two carrier parts 45, 48 in the region of the mating surfaces 47, 50, there is a sealing element 78, which is shown by way of example in FIG. 4 . In an embodiment, the sealing element 78 comprises a plurality of separate ring seals 79. In an embodiment, each ring seal 79 is inserted into a first ring groove 80 at the first mating surface 47 of the first carrier part 45. The first ring groove 80 completely surrounds a corresponding one of the first flow passage cavities 60. The first ring groove 80 is sized such that the inserted ring seal 79 extends out of the ring groove 80 onto the flat surface portion 47 a of the first mating surface 47.

[0066] In an embodiment, the second coupling surface 50 also has a second ring groove 81 that completely surrounds a corresponding one of the second flow passage cavities 62. The second ring groove 81 may be configured according to the first ring groove 80. When the first and second carrier parts 45, 48 are connected to each other using the opposing coupling surfaces 47, 50, each ring seal 79 is seated in the first ring groove 80 and the second ring groove 81, as shown schematically in Figure 8. This ensures good positioning of the ring seals 79 and their respective sealing effectiveness.

[0067] In a variant to the preferred embodiment, at least one ring groove 80 or 81 may be present only in one of the carrier parts 45, 48 in order to seal the main flow path 72 after assembly of the carrier parts 45, 48. In a further variant, a plate-shaped sealing member may be arranged between the two carrier parts 45, 48, which has through holes in the area of ​​the first flow path cavity 60 and the second flow path cavity 62 and which abuts against the first flow path cavity 60 and the second flow path cavity 62 with the flat surface portions 47a, 50a of the joining surfaces 47, 50 surrounding the first flow path cavity 60 and the second flow path cavity 62.

[0068] In other embodiments, the seal portion 78 may be connected to one of the carrier portions 45, 48 by substrate bonding or adhesive bonding. For example, the seal portion 78 may be glued to one of the mating surfaces 47, 50 or may be attached to one of the carrier portions 45, 48 by two-part injection molding during manufacture of the carrier portions 45, 48.

[0069] In a preferred embodiment, the carrier parts 45, 48 are made entirely of a transparent material, at least in the region of the joining surfaces 47, 50, so that a visual inspection can be carried out in the fitted and assembled state to ensure that the ring seal 79 is correctly positioned in the assigned ring groove 80 or 81 and that the sealing effect can be guaranteed.

[0070] Yet another independent aspect of the inventive fluid control device 12 relates to the manufacture of the carrier parts 45, 48. The carrier parts 45, 48 are preferably constructed as injection-molded parts, with the mold closing direction being preferably selected to coincide with the extension direction of the branch channels 61, 63. In injection molding, the mold closing direction is the direction in which two mold halves are moved relative to each other to open and close the injection mold.

[0071] Each branch path 61, 63 of the carrier parts 45, 48 is configured without undercuts in its direction of extension from one end to the other. In this direction, each branch path 61, 63 may be configured with a conical tapered shape. Each first branch path 61, which originates 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, extends without undercuts. Correspondingly, each second branch path 63 extends without undercuts from the first coupling surface 50 to the first mounting surface 49 or the free end of the nozzle 64, or vice versa, from the free end of the nozzle 64 or the second mounting surface 49 to the second coupling surface 50. This configuration of the branch paths 61, 63 is free of undercuts, which allows the carrier parts 45, 48 to be constructed as injection-molded parts in a very simple manner.

[0072] The present invention relates to a fluid control device 12 for a medical device 10, in particular a medical device for argon plasma coagulation. The fluid control device 12 has a fluid control circuit 19 with at least one fluid control component 21 through which a fluid flows. 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 carrier part 45 has a first mating surface 47, and a second carrier part 48 has a second mating surface 50. The first mating surface 47 is provided with at least one first flow path cavity 60, and / or the second mating surface 50 is provided with at least one second flow path cavity 62. While the carrier parts 45, 48 are connected at their opposing mating surfaces 47, 50, at least one main flow path 72 is formed in the region of the separated position. Thus, each main flow path 74 is defined in part by the first carrier part 45 and in part by the second carrier part 48. The first carrier part 45 may have a first mounting surface 46 for at least one fluid control component 21. The second carrier part 48 may have a second mounting surface 49 for at least one electrical and / or electronic component 51 of the control circuit 20. In addition to or instead of mounting components on the mounting surfaces 46, 49, the carrier parts 45, 48 may be constructed as injection-molded parts. Another independent aspect relates to the hydraulic connections in the fluid control circuit 19, where a flow detector 32 is arranged upstream of the actuator, via which the fluid flow from the outlet point 24 of the fluid control device 12 can be controlled or feedback-controlled under the control of the control circuit 20. [Explanation of symbols]

[0073] 10 Medical Devices 11 Fluid source 12 Fluid control device 13 Equipment 14 High voltage source 15 electrodes 19 Fluid control circuit 20 Control circuit 21 Fluid control parts 22 Flow path section 23 Inflow point 24 Outflow Point 26 Switching valve 27 Pressure Regulating Valve 28 Proportional Valve 29 Filters 30 Control Unit 31 Sensor section 32 Flow detector 33 flow measurement channels 33a First channel part 33b Second channel part 33c Connection channel part 34 pressure measurement channels 35 1st pressure measurement channel pair 36 Second pressure measurement channel pair 37 pressure sensor 38 measurement opening 45 First Carrier Section 46 First mounting surface 47 1st bonding surface 47a Flat surface portion of first bonding surface 48 Second Carrier Section 49 Second mounting surface 50 Second bonding surface 50a: Flat surface portion of second bonding surface 51 Electrical and / or electronic components 52 Circuit board section 53 Component support circuit board section 54 Flexible connection part 55 Control wiring 56 Mounting pins 60 First flow path cavity 61 First Junction 62 Second flow path cavity 63 Second Fork 64 nozzles 65 Free end of nozzle 66 Measuring element 67 Radial seal member 68 Ring Cavity 72 Main Channel 73 First measurement channel cavity 74 Second measurement channel cavity 78 Seal part 79 Ring Seal 80 First ring groove 81 Second ring groove E Input signal F Flow direction S control signal

Claims

1. A fluid control device (12) for a medical device (10), comprising: a fluid control circuit (19) having at least one flow path section (22) and at least one fluid control component (21) disposed between an inlet point (23) and an outlet point (24); a control circuit (20) configured to control the at least one fluid control component (21) of the fluid control circuit (19), the control circuit (20) having at least one electric and / or electronic component (51); The main flow path (72) of the flow path section (22) forms a flow measurement channel (33) of the flow meter (32), and at least one pressure measurement channel pair (35 or 36) having two pressure measurement channels (34) is provided, and the pressure measurement channels (34) of the pressure measurement channel pair are connected to the flow measurement channel (33) at positions spaced apart from each other in the flow direction (F). Fluid control device.

2. A separate pressure sensor (37) is connected to each pressure measurement channel (34), or a differential pressure sensor is connected to multiple pressure measurement channels (34) in one pressure measurement channel pair (35 or 36). The fluid control device according to claim 1 .

3. a first pressure measurement channel pair (35) is provided, the plurality of pressure measurement channels (34) of the first pressure measurement channel pair (35) communicating with a first channel portion (33a) of the flow measurement channel (33) having a first flow cross section; a second pressure measurement channel pair (36) is provided, the pressure measurement channels (34) of the second pressure measurement channel pair (36) communicating with a second channel portion (33b) of the flow measurement channel (33) having a second flow cross section; The first flow cross section and the second flow cross section have different areas. The fluid control device according to claim 1 or 2.

4. A separate pressure sensor (37) is connected to each pressure measurement channel (34), or a differential pressure sensor is connected to multiple pressure measurement channels (34) of one pressure measurement channel pair (35 or 36); The at least two pressure values ​​measured by the pressure sensor (37) are transmitted to a control unit (30) or evaluation unit of the control circuit (20) configured to determine the mass or volume flow rate of the fluid flowing through the flow measurement channel (33) based on the at least two pressure values. The fluid control device according to claim 3 .

5. The fluid control circuit (19) comprises a series connection of an actuator and the flow meter (32), the flow meter (32) being arranged upstream of the actuator in the flow direction (F). The fluid control device according to claim 1 .

6. In the flow direction (F), the flow rate measuring device (32) is arranged between the pressure limiting device or pressure control device or pressure regulator and the actuator. The fluid control device according to claim 1 .

7. a first carrier part (45) having a first mounting surface (46) and a first coupling surface (47), and a second carrier part (48) having a second mounting surface (49) and a second coupling surface (50); the at least one fluid control component (21) of the fluid control circuit (19) and the at least one electrical and / or electronic component (51) of the control circuit (20) are arranged on the mounting surfaces (46, 49) of the carrier parts (45, 48); At least one first flow cavity (60) is provided in the first joining surface (47) and / or at least one second flow cavity (62) is provided in the second joining surface (50), The two carrier parts (45, 48) are connected to each other at the joining surfaces (47, 50) such that the at least one first flow path cavity (60) and / or the at least one second flow path cavity (62) define at least one main flow path (72) of the flow path part (22). The fluid control device according to claim 1 .

8. At least one first flow path cavity (60) and at least one second flow path cavity (62) are provided, and each first flow path cavity (60) and its corresponding one second flow path cavity (62) form one main flow path (72) of the flow path section (22). The fluid control device according to claim 7.

9. Each of the first flow cavity (60) and each of the second flow cavity (62) has a semicircular cross section. The fluid control device according to claim 8 .

10. The first carrier part (45) and the second carrier part (48) are formed by respective injection molded parts. The fluid control device according to any one of claims 1 to 9.

11. At least one first fluid branch (61) is present in the first carrier part (45), extending between the first mounting surface (46) and the first coupling surface (47) and having no undercuts in at least one direction of extension 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). The fluid control device according to any one of claims 7 to 9.

12. At least one second fluid branch (63) is present in the second carrier part (48), extending between the second mounting surface (49) and the second coupling surface (50) and free of undercuts in at least one direction of extension 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). The fluid control device according to any one of claims 7 to 9.

13. The one or more first flow passage cavities (60) and / or the one or more second flow passage cavities (62) form a plurality of main flow passages (72) spaced apart from one another at or along the joining surfaces (47, 50). The fluid control device according to any one of claims 7 to 9.

14. Each fluid control component (21) is disposed on the first mounting surface (46). The fluid control device according to any one of claims 7 to 9.

15. Each electric and / or electronic component (51) is disposed on the second mounting surface (49). The fluid control device according to any one of claims 7 to 9.

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