Radiation emission component for the temperature-compensated optical detection of an oxygen content of a fluid
Patent Information
- Application Number
- EP2023790668
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-19
- Filing Date
- 2023-10-18
- Publication Date
- 2025-08-27
AI Technical Summary
The production of existing radiation emission components for temperature-compensated optical detection of oxygen in fluids is complex due to the difficulty in gluing metal foils to plastic base bodies, which can lead to inaccuracies and reliability issues, especially in ventilation applications where detachment can result in metal foils being carried away by gas flow.
A radiation emission component with a base body and base layer body made entirely of plastic, connected in one piece through their respective plastic materials, allowing for a secure and adhesive-free connection via welding processes, and featuring a recess design for temperature detection that ensures accurate temperature compensation without interference with the luminophore area.
This design enhances operational reliability and simplifies manufacturing while maintaining accuracy in oxygen content detection, avoiding the complexities and inaccuracies associated with metal foil gluing and ensuring the plastic components remain securely attached.
Smart Images
Figure 1.1
Abstract
Description
[0001] Radiation emission component for temperature-compensated optical detection of the oxygen content of a fluid
[0002] Description
[0003] The present invention relates to a radiation-emitting component for temperature-compensated optical detection of an oxygen content of a fluid, wherein the radiation-emitting component comprises a contact surface wettable by the fluid and a coupling surface different from the contact surface for coupling to a radiation-sensitive sensor arrangement.
[0004] The radiation-emitting component has a luminophore-containing region. Typically, a luminophore in the luminophore-containing region can be excited by irradiation with a first electromagnetic radiation of a first wavelength to emit a second electromagnetic radiation of a second wavelength different from the first wavelength. The excited emission behavior of the luminophore in the luminophore-containing region depends on the oxygen partial pressure in a fluid contacting the contact surface. The luminophore is accessible to oxygen in a first section of the contact surface. Its emission of excited radiation can be quenched in a conventional manner by contact of the luminophore with oxygen molecules.
[0005] The radiation-emitting component further comprises a temperature-sensing region that emits infrared radiation. The temperature-sensing region is offset relative to the luminophore-containing region in a reference direction along the contact surface.
[0006] The radiation-emitting component has, in the section in which the temperature detection area is arranged, a base body with a recess extending towards the contact surface. The recess is covered by a base comprising a base layer body. A surface of the base layer body facing away from the recess forms a second section of the contact surface, different from the first section. Such a radiation-emitting component is known as a layered body from WO 2018 / - 166847 A1. In the known radiation-emitting component, the base layer body is preferably made of a metal with good thermal conductivity, in particular of aluminum. The known base layer body made of metal foil is adhesively bonded to the end face of the base body on the side thereof facing the measuring fluid during operation in such a way that it covers a recess passing through the base body. The metal foil, i.e. the base layer body, can be adhesively bonded to its or its side.its side facing the recess must be coated with a black lacquer in order to achieve a higher emissivity in the relevant wavelength range than would be the case with the bare metal surface.
[0007] Such radiation-emitting components are preferably arranged to measure the oxygen content of respiratory gas in ventilation lines of ventilators for artificially respiring patients, for example, in a measuring cuvette through which respiratory gas flows, which can be coupled to a radiation-sensitive sensor arrangement for radiation exchange. The measuring fluid is then a measuring gas, namely the respiratory gas.
[0008] The known "quenching" of the luminophore used by the radiation-emitting component to detect the oxygen content in the respiratory gas of a ventilated patient depends not only on the oxygen partial pressure of the respiratory gas but also on the temperature of the luminophore. In order to evaluate the second electromagnetic radiation emitted by the luminophore-containing region in a way that compensates for the unavoidable temperature influence and to determine the most accurate oxygen content in the respiratory gas, the temperature detection region is arranged at the specified spatial offset from the luminophore-containing region. The infrared radiation emitted by the temperature detection region is a measure of its temperature. Due to the recess and the relatively thin design of the base of the recess, formed in the prior art by a metal foil that may be coated if desired, the temperature of the base or the surface of the region is determined.The temperature of the free surface of the base facing the recess is approximately equal to the temperature of the luminophore in the luminophore-containing region. Due to the base covering the recess, the recess is designed as a blind hole.
[0009] Thus, for temperature compensation of the detected quenching effect, a temperature corresponding sufficiently accurately to the temperature of the luminophore can be detected spatially away from the luminophore, so that the two radiation detections, once in the luminophore-containing area and once again in the temperature detection area, do not interfere with each other.
[0010] The above information on the field of application and the mode of operation of the radiation-emitting component and its areas: luminophore-containing area and temperature detection area, apply to the radiation-emitting component of the prior art as well as to the radiation-emitting component according to the invention presented here.
[0011] However, the production of the known radiation-emitting component is complex, as the metal foil, possibly after coating, must be glued to the base body of the temperature detection area, which is usually made of plastic. This bonding process is not only cumbersome due to the adhesive application and positioning of the components to be bonded relative to one another, ensuring trouble-free curing of the adhesive, etc., but also requires the use of specially adapted adhesives, as aluminum foils in particular are not readily bondable. Metal foils either require pretreatment, such as the application of a primer as an adhesion promoter layer, or a special adhesive must be selected that is capable of permanently bonding a metal foil to the base body.Detachment of the metal foil from the base body on the contact side is unacceptable, especially in ventilation applications, as the detached metal foil can then be carried along by the respiratory gas flow to the patient. Therefore, the object of the present invention is to provide a radiation-emitting component that operates without loss of accuracy, can be operated with high operational reliability, and is nevertheless easy to manufacture.
[0012] This object is achieved according to the present invention for a radiation-emitting component of the type mentioned above in that the base body and the base layer body each comprise plastic material, wherein the base body and the base layer body are integrally connected to one another by means of their respective plastic materials. This integral connection is clearly a particularly secure connection. For this purpose, it is necessary to form the base layer body and the base body each with plastic material in order to be able to provide the integral material connection through the two plastic materials.
[0013] It is obvious that plastic material generally has a lower thermal conductivity than the metal foil known from the prior art. However, this disadvantage of the base can be compensated for by a sufficiently thin design of the base between its contact surface wettable by the measuring fluid and its opposite free surface, which radiates infrared radiation toward the recess.
[0014] The contact surface of the radiation-emitting component is wettable by fluid, which essentially indicates that the contact surface of the radiation-emitting component is an exposed surface of the component. This ensures wettability by the measuring fluid to be detected.
[0015] The coupling surface of the radiation-emitting component is also an exposed surface. It is spatially arranged or formed at a different location than the contact surface and is therefore different from the contact surface. The coupling surface, as an exposed surface of the base body, is preferably located opposite the contact surface along a path or axis of the depth extension of the recess. In this case, the recess extends like a blind hole, starting from a surface of the base body opposite the contact surface, which is generally free, toward the contact surface. The coupling surface serves to couple the radiation-sensitive sensor arrangement. The first electromagnetic radiation for radiatively exciting the luminophore in the luminophore-containing region can preferably be introduced into the base body through the coupling surface.Likewise, the second electromagnetic radiation emitted by the luminophore preferably exits the base body through the coupling surface. Furthermore, infrared radiation emanating from the coupling surface is detected by an infrared sensor of the radiation-sensitive sensor arrangement.
[0016] In principle, it is possible for the infrared radiation emitted from the bottom of the recess in the temperature detection area to be radiated in a different direction than the second electromagnetic radiation in the luminophore-containing area, i.e., for the coupling surface to have differently oriented areas in the luminophore-containing area and in the temperature detection area. Preferably, the coupling surface of the radiation-emitting component is uniformly oriented across the luminophore-containing area and the temperature detection area, in order, on the one hand, to form the coupling surface with the smallest possible surface area and / or installation space requirement, and, on the other hand, to facilitate coupling of the radiation-sensitive sensor arrangement.
[0017] According to a first possible embodiment of the radiation-emitting component, it can be provided that the plastic material of the base body and the plastic material of the base layer body are fused together in regions. This enables separate production of the base body, on the one hand, and the base layer body, on the other, using sufficiently compatible plastic materials so that they can be fused together directly and without the use of adhesive using welding processes such as ultrasonic welding or mirror welding, to name just two possible examples. This first possible embodiment allows for considerable design freedom in the design of the base layer body in particular, but requires an additional work step in the production of the radiation-emitting component with the joining process for fusing the base body and the base layer body.According to a second possible embodiment, the base body and the base layer body can be formed monolithically from the same plastic material in one piece. Although machining of the temperature sensing area by removing material from the area of the recess while leaving the base made of solid material is conceivable in principle, such machining is not preferred due to the long manufacturing time and the necessary time-consuming clamping processes in preparation for machining. A one-piece production of the base body, recess, and base by a primary forming process, such as casting or, particularly preferably, injection molding, is more preferred. According to current knowledge, the base layer body manufactured in one piece with the base body can be manufactured without difficulty with a thickness in the range of between 200 μm and 300 μm.If smaller thicknesses of the base layer body are required, a so-called injection-compression molding process can be used for thicknesses in the range of 100 μm to 200 μm. In this process, a near-net-shape blank is first injection-molded. While still in the injection mold, the base region of the recess, and thus the base layer body, is subsequently formed in a second molding process using a slider acting as a stamping die. The layer thicknesses that can be achieved by injection molding alone or by injection-compression molding depend on the specific process and the plastic material used. Certainly, in the thickness range of 80 to 120 μm, depending on the plastic material to be molded, there is a certain degree of choice for producing the base region in one piece with the base body using one or the other process.This one-piece monolithic production of the base body and the soil layer body achieves the most durable and strong connection between the aforementioned bodies.
[0018] To ensure that the base layer body can be integrally connected to the base body in one way or another, the base layer body is preferably made of 100% plastic material. The plastic material can be plastic filled with a filler material, such as particles and / or fibers, to increase its strength, such as tensile strength and flexural strength. The filler material can, but does not have to, consist of plastic or comprise plastic. Alternatively, the plastic material can be unfilled plastic, which is preferred with regard to the most spatially homogeneous material properties of the temperature sensing section. Furthermore, an optically transparent base layer body can be achieved with an unfilled plastic, which is generally not possible with filled plastic.To simplify the production of the one-piece connection, the plastic is preferably thermoplastic, regardless of whether it is used as a matrix plastic of a filled plastic material or as an unfilled plastic.
[0019] The base layer body can be designed as a plastic film, particularly if it is manufactured separately from the base body and joined to it in one piece by a welding process. The plastic film can be formed from multiple layers, in particular plastic material layers. For example, the plastic film can have a temperature information layer with a particularly advantageously low transmittance in the infrared wavelength range relevant for the planned infrared temperature measurement. Furthermore, the temperature information layer can have an external connecting layer on its side facing the base body or the recess, which can be particularly well melt-bonded to the plastic of the base body, in particular by welding or sealing. The connecting layer can be thinner than the temperature information layer.Since the base layer body forms the above-mentioned second section of the contact surface and thus an exposed surface facing away from the recess in the base body in order to form the temperature detection area as simply as possible, a surface of the temperature information layer can form the second section of the contact surface.
[0020] To avoid mutual undesirable influences of the respective relevant radiations, the first and second sections of the contact surface are arranged offset from one another in a reference direction along the contact surface, for example, in the longitudinal direction of the radiation-emitting component. Optionally, the first and second sections of the contact surface can additionally or alternatively be arranged offset relative to one another in the reference direction parallel to the contact surface.
[0021] To achieve the simplest possible manufacturing and production of the temperature detection area, the base layer body preferably comprises only one type of plastic. This type of plastic can be, for example, styrene, polyester, polyolefin, etc., to name just a few examples. The base body preferably also comprises only one type of plastic. Different plastics of the same type are generally compatible with each other and can be joined together in one piece by melting.
[0022] Although different plastics of the same type, such as polyethylene and polypropylene as polyolefins, are compatible with one another, the base layer body, and preferably also the base body, particularly preferably comprises only one plastic. This plastic is preferably the same plastic for both components consisting of the base body and the base layer body, particularly in the case of a one-piece, monolithic design. This plastic is preferably the plastic methyl methacrylate acrylonitrile butadiene styrene (MABS), which has already proven itself in applications for medical devices. The base layer body is particularly preferably a single-layer body with only a single layer, such as is obtainable, for example, through injection molding or injection-compression molding. A separate base layer body, for example in the form of a film, can also be a single-layer body.In addition to the simplification achieved by using only a single plastic, the soil layer body is further simplified by forming a single layer. However, this does not preclude the subsequent application of one or more coatings to the soil layer body, for example, to adapt the emission and / or absorption behavior of the soil to the intended application of detecting the emitted infrared radiation.
[0023] In the nomenclature of the present application, a coating subsequently applied viscously to a previously produced soil layer body and subsequently cured and / or dried is part of the soil, but not part of the soil layer body.
[0024] In order to ensure rapid adaptation of the temperature of the bottom layer body to the temperature of the luminophore in the luminophore-containing region when the temperature of the measuring fluid wetting the contact surface changes, and to ensure a sufficiently stable formation of the temperature detection region, the bottom layer body is preferably thinner than the base body surrounding the recess. The bottom layer body or the base of the temperature detection region can have a thickness in the range of 50 μm to 300 μm. To provide sufficient rigidity and strength, the base body is at least 500 μm thick, preferably at least 1 mm, and particularly preferably several millimeters thick.
[0025] The thickness of the radiation-emitting component in the temperature detection area is preferably measured along the direction of the depth extension of the recess.
[0026] Preferably, the portion of the coupling surface through which the first electromagnetic radiation is introduced into the base body and / or the second electromagnetic radiation exits it forms a first portion of the coupling surface. At this first portion of the coupling surface, preferably only the first electromagnetic radiation is introduced and the second electromagnetic radiation is detected, but no infrared radiation.
[0027] The exposed surface of the base facing the recess and opposite the second section of the contact surface forms a second section of the coupling surface. To avoid mutual interference in the detection of infrared radiation, on the one hand, and in the emission of the first electromagnetic radiation and the detection of the second electromagnetic radiation, on the other hand, the second section of the coupling surface is offset relative to the first section of the coupling surface in a direction along the coupling surface, in particular parallel to the coupling surface. At the second section of the coupling surface, preferably only the infrared radiation emitted by the second section is detected, but no radiation to or from the luminophore-containing region.
[0028] Due to the design of the recess, the second section of the coupling surface is offset relative to the first section of the coupling surface in a direction in the direction of the depth of the recess. As already explained above, the direction of the depth of the recess corresponds to the thickness direction of the base body. Preferably, the coupling surface and the contact surface are parallel to one another. Preferably, the first sections of the contact surface and the coupling surface lie opposite one another in the thickness direction of the base body. Additionally or alternatively, the second sections of the contact surface and the coupling surface lie opposite one another in the thickness direction of the base body, in particular the base of the recess. Further preferably, the second section of the coupling surface is also offset in the reference direction relative to the first section of the coupling surface.
[0029] A plastic material of the base layer body that is advantageous for temperature detection by infrared radiation emission preferably has a transmittance of no more than 20% for infrared radiation in a wavelength range from 5500 nm to 14000 nm. Preferably, the entire thickness region of the base layer body between its opposite outer surfaces is formed from the plastic material with the low transmittance of 20% or less.
[0030] Even more preferably, the plastic material of the base layer body has a transmittance for infrared radiation of no more than 5% in the wavelength range. The above-mentioned plastic MABS has the advantageously low transmittance of no more than 5% in the wavelength range. This ensures that it is not infrared radiation emitted by the measuring gas or fluid beyond the contact surface that reaches an infrared sensor, but rather infrared radiation actually emitted by the base layer body. This prevents incorrect measurements in which the temperature of the measuring fluid replaces the temperature of the base layer body or the second section of the coupling surface. Due to the advantageously low transmittance of no more than 5%, the plastic material of the base layer body can directly form the surface of the base facing the recess.Thus, the surface of an injection-molded or injection-compressed base layer body or a film surface of a base layer body formed as a film can form the surface facing the recess or the second section of the coupling surface. An additional coating to adapt the radiation behavior of the base to the measurement conditions is advantageously not required in this case. However, if the transmittance of the plastic of the base layer body is too high in the relevant wavelength range, the base layer body can have a coating on its surface facing away from the contact surface and / or on its surface facing the contact surface or forming a section of the contact surface.If a coating is required, its arrangement on the surface facing away from the contact surface is preferred, since this points directly to an infrared sensor arranged on the side of the coupling surface and can preferably only be opposite this with an intervening air gap. This coating is preferably subsequently applied to the base layer body. The coating is preferably selected such that the base, in the direction of the recess, has an absorption coefficient of at least 95% and / or an emissivity of at least 95% in the wavelength range from 5500 nm to 14000 nm. The coating is preferably formed from a material that has an absorption coefficient of at least 95% and / or an emissivity of at least 95%. Such a coating is available, for example, as a deep black coating from ACM COATINGS GmbH, Rudelsburgpromenade 20c, in 06628 Naumburg - Bad Kosen (DE).
[0031] To avoid interference from interfering radiation, the temperature detection area, in particular the soil, particularly preferably the soil layer body, is preferably free of luminophore.
[0032] Just like the temperature detection region, the radiation-emitting component can have a luminophore base body. To dope the luminophore-containing region of the radiation-emitting component, the luminophore base body can support an oxygen-permeable foil. A first surface of the foil preferably forms the first section of the contact surface of the radiation-emitting component. Likewise, the luminophore is preferably arranged between a second surface of the semipermeable foil, opposite the first surface, and the luminophore base body. Thus, while the luminophore is in principle accessible to oxygen to quench the excited radiation, it is nevertheless protected from the influence of the measuring fluid wetting the contact surface.Although the luminophore can in principle be arranged on a surface of the luminophore base body, it is preferred for manufacturing reasons if the luminophore is arranged in the film or on the surface of the film facing the luminophore base body.
[0033] One material for producing an oxygen-permeable film that can serve as a substrate for a luminophore layer is polyvinylidene fluoride. However, it should not be ruled out that the luminophore itself forms the first section of the contact surface and is directly wettable by the measuring fluid. However, due to the disruptive effects of the measuring fluid on the luminophore due to entrained moisture and other contaminants, this design is not preferred.
[0034] The surface of the oxygen-permeable foil forming the first section of the contact surface can be arranged flush with the second section of the contact surface. Alternatively, the surface of the oxygen-permeable foil forming the first section of the contact surface can be offset in the depth direction, and thus preferably also in the thickness direction of the luminophore base body, relative to the second section of the contact surface, approximately by the thickness of the foil. In addition, the thickness of a luminophore layer supported by the oxygen-permeable foil can also contribute to the amount of the offset.
[0035] So that the first electromagnetic radiation for exciting the luminophore can reach the luminophore through the luminophore base body and thus the excited second electromagnetic radiation can also reach the coupled radiation-sensitive sensor arrangement through the luminophore base body, the luminophore base body preferably has a transmittance of at least 80% for radiation in a first wavelength range from 450 to 480 nm and in a second wavelength range from 730 to 1100 nm. Preferably of at least 90%, particularly preferably of at least 95%. The above-mentioned plastic MABS also has the desired high transmittances in the latter wavelength ranges. The luminophore base body is therefore preferably made of MABS.In principle, it is conceivable to manufacture the base body of the temperature detection region and the luminophore base body separately and to join or assemble them to form a base body of the radiation-emitting component. In a particularly preferred embodiment, however, the base body and the luminophore base body are formed as a single, monolithic radiation-emitting component base body. The base body and the luminophore base body each form a section of this radiation-emitting component base body. Preferably, the section of the base body and the section of the luminophore base body are arranged offset from one another in the reference direction.
[0036] Since both the luminophore base body and the base layer body can preferably be made of thermoplastic MABS, and since the base body of the temperature detection region and the base layer body are more preferably made integrally connected to one another, the base body of the temperature detection region is preferably also made of MABS. Consequently, in a particularly preferred embodiment, the radiation-emitting component base body and the base layer body integrally connected to it are made of MABS, even more preferably by injection molding or injection-compression molding.
[0037] In a Cartesian coordinate system consisting of the longitudinal direction, width direction, and thickness direction, the reference direction is preferably the longitudinal direction of the radiation-emitting component. In the longitudinal direction, the radiation-emitting component has its largest dimension among the aforementioned Cartesian coordinate directions, thus providing sufficient space for the formation of the temperature detection region on the one hand and the luminophore-containing region on the other side.
[0038] In an advantageous development, the present invention relates to a measuring cuvette with a radiation-emitting component, as described and developed above. The measuring cuvette has a gas space with a receiving volume for receiving a measuring gas as the measuring fluid. The contact surface forms a wall of the gas space that delimits the receiving volume and is exposed to the receiving volume. Furthermore, at least a portion of the coupling surface is exposed to the outside environment of the measuring cuvette. To facilitate the coupling of a radiation-sensitive sensor arrangement, the first and second regions of the coupling surface on the measuring cuvette preferably point in identical directions. Preferably, at least the first region of the coupling surface is flat.Likewise, the second region of the coupling surface is preferably flat and particularly preferably parallel to the first region of the coupling surface, although it is arranged offset relative to the first region in the direction of the depth extension of the recess due to the recess.
[0039] To enable the determination of the carbon dioxide content in the measurement gas in addition to the temperature-compensated detection of the oxygen content of the measurement gas provided by the radiation-emitting component, at least one boundary wall of the gas chamber has a window transparent to radiation in the infrared wavelength range. This allows the carbon dioxide content of the respiratory gas to be determined using infrared spectroscopy based on its absorption behavior. Preferably, the at least one boundary wall with the IR-transparent window is a different boundary wall than the wall or contact surface formed by the radiation-emitting component. Particularly preferably, the boundary wall having the IR-transparent window has a surface normal on its inner surface wetted by the measurement gas, which encloses an angle of 80 to 100°, preferably 90°, with the surface normal of the contact surface.In a particularly preferred manner, the measuring cuvette is designed to irradiate the gas space with infrared radiation for measuring the carbon dioxide content of the measuring gas, so that two boundary walls opposite each other across the gas space each have a window made of material permeable to radiation in the infrared wavelength range.
[0040] In principle, it can be envisaged that the gas space is filled with the measuring gas and that the measuring gas is measured after filling. The preferred application of the measuring cuvette, however, is the metrological measurement of respiratory gas as the measuring gas, specifically during its supply to the patient and / or its removal from the patient. Therefore, the gas space can preferably be flowed through by measuring gas along one flow direction, preferably along two opposite flow directions. The measuring cuvette preferably forms part of a ventilation line in order to supply inspiratory respiratory gas to a patient and to remove expiratory respiratory gas. Therefore, in a preferred development of the present invention, the radiation emission component can be located in the flow direction between two connection formations, wherein each of the connection formations is designed to connect a line carrying the measuring gas.In principle, the measuring cuvette is not limited to applications in ventilation lines, although this is preferred.
[0041] In a further advantageous embodiment, the present invention relates to a sensor device comprising a measuring cuvette as described and further developed above, and further comprising a radiation-sensitive sensor arrangement with a sensor housing. The sensor housing accommodates at least: a radiation source for emitting the first electromagnetic radiation, a first radiation sensor for detecting the second electromagnetic radiation, and at least one infrared sensor for detecting infrared radiation in a wavelength range for which the base of the temperature detection region has a transmittance of no more than 20%, preferably no more than 10%, particularly preferably no more than 5%.
[0042] The sensor housing, which can preferably be reused for subsequent measurement tasks after completion of a measurement task, is detachably attachable to a section of the measuring cuvette containing the radiation-emitting component. Preferably, the sensor housing can be slid astride the section of the measuring cuvette containing the radiation-emitting component and removed therefrom. Likewise, the sensor housing can preferably be secured to the measuring cuvette in the coupled state by means of an overridable latch or a releasable locking mechanism.
[0043] The present invention will be explained in more detail below with reference to the accompanying drawings. Figure 1 shows a longitudinal sectional view through a first embodiment of a radiation-emitting component of the present application,
[0044] Fig. 2 is a perspective view of a second embodiment of a radiation emitting component of the present application,
[0045] Fig. 3 is a perspective view of a measuring cuvette with a radiation emission component of the present application,
[0046] Fig. 4 is a frontal view of the measuring cuvette of Fig. 3 opposite to the longitudinal direction L,
[0047] Fig. 5 is a cross-sectional view of the measuring cuvette of Figures 3 and 4, wherein the offset cutting plane oriented orthogonally to the longitudinal direction L runs through the gas space of the measuring cuvette and through the recess in the temperature detection area of the radiation emission component,
[0048] Fig. 6 is a perspective view of a radiation-sensitive sensor arrangement for detachable coupling with the measuring cuvette of Figures 3 to 5, and
[0049] Fig. 7 is a bottom view of the radiation-sensitive sensor arrangement of Figure 6.
[0050] In Figure 1, a first embodiment of a radiation-emitting component according to the invention is generally designated 10. The radiation-emitting component 10 comprises a radiation-emitting component base body 12 made of MABS, which is produced in one piece by injection molding.
[0051] A Cartesian coordinate system consisting of pairs of mutually orthogonal coordinate directions: longitudinal direction L, width direction B, and thickness direction D, is indicated in the figures showing a radiation-emitting component to clearly illustrate the respective orientation of the radiation-emitting component in the respective figure. The radiation-emitting component 10 has a luminophore-containing region 14 and a temperature-sensing region 16, which are arranged offset relative to one another in the longitudinal direction L as a reference direction.
[0052] The radiation-emitting component 10 has a contact surface 18 that can be wetted by a fluid, in particular a gas, to be measured during operation of the radiation-emitting component 10. A portion of the contact surface 18 located in the luminophore-containing region 14 forms a first portion 20 of the contact surface 18. A portion of the contact surface 18 located in the temperature detection region 16 forms a second portion 22 of the contact surface 18.
[0053] Arranged at a distance from the contact surface 18 in the thickness direction D or opposite thereto, the radiation-emitting component 10 has a coupling surface 24 which serves for the temporary, detachable coupling to a radiation-sensitive sensor arrangement (see, for example, the radiation-sensitive sensor arrangement 80 in Figures 6 and 7) in order to transmit radiation information from the radiation-emitting component 10 to the radiation-sensitive sensor arrangement and to transmit excitation radiation, which is referred to as first electromagnetic radiation in the introduction to the description, to the luminophore in the luminophore-containing region 14 in order to excite the latter to emit a second electromagnetic radiation whose wavelength is different from that of the excitation radiation.
[0054] What has been said about the contact surface 18 applies analogously to the coupling surface 24: a section of the coupling surface 24 located in the luminophore-containing region 14 forms a first section 26 of the coupling surface 24 and a section of the coupling surface 24 located in the temperature detection region 16 forms a second section 28 of the coupling surface 24.
[0055] The luminophore-containing region 14 is defined by the arrangement of the luminophore. An oxygen-permeable film 30 made of polyvinylidene fluoride is integrally connected to a luminophore base body 32 in the luminophore-containing region 14, for example, by ultrasonic welding. The luminophore base body 32 forms a section of the radiation-emitting component base body 12. The luminophore base body 32 is formed by injection molding in a one-piece, monolithic manner with a base body 34 of the temperature-sensing region 16. The base body 34 also forms a section of the radiation-emitting component base body 12.
[0056] The film 30, with its free surface 31 on its side facing away from the luminophore base body 32, forms the first section 20 of the contact surface 18 and, on its opposite surface 33, carries a thin layer 36 containing the luminophore, indicated by close dotting. The luminophore is thus arranged between the luminophore base body 32 and the film 30 and protected from external influences. The film 30 made of polyvinylidene fluoride is permeable to oxygen, so that oxygen molecules can reach the luminophore in the layer 36 in the luminophore-containing region 14 via the contact surface 18 or via the first section 20 thereof and can influence its radiation behavior by quenching in a manner known per se. The quantity of oxygen molecules reaching the luminophore per unit time is proportional to the oxygen partial pressure in the measuring fluid MF wetting the contact surface 18 or the first section 20 thereof.The measuring fluid MF is symbolized in the representation as a point cloud with a thinner point density than that of layer 36.
[0057] The temperature detection area 16 is characterized by a blind-hole-like recess 38. The recess 38 extends from a free surface 25 of the radiation-emitting component base body 12 or the base body 34, which is opposite the contact surface 25 in the thickness direction D, along an axis 40 of the depth extension to the contact surface 18. In the illustrated embodiment, the surface 25 forms a common flat surface with the second section 26 of the coupling surface 24.
[0058] The recess 38 is covered by a base 42, which in the illustrated embodiment is formed by a base layer body 44 formed integrally with the base body 34 during injection molding. The base layer body 44, thus formed exclusively from MABS, forms the second section of the contact surface 18 with its free surface 45 facing away from the recess 38 and forms the second section of the coupling surface 24 with its opposite free surface 47 facing the recess 38.
[0059] Due to its construction from MABS, the bottom layer body 44 is virtually opaque in the wavelength range of 5,500 to 14,000 nm, which is relevant for infrared temperature detection, or has a transmittance of less than 5%. In the illustrated embodiment, the bottom layer body 44 has a thickness of approximately 200 pm to 240 pm.
[0060] Due to its one-piece, monolithic design, together with the base body 34 or the radiation-emitting component base body 12, it is arranged on the base body 34 and connected to it with high strength. In the illustrated embodiment, detachment of the base layer body 44 from the base body 34 is only conceivable by deliberate destruction of the temperature detection area 16 of the radiation-emitting component 10. This requires considerable force, which significantly exceeds the forces occurring during normal operation. At the same time, the base layer body 44, together with the base body 34 and the radiation-emitting component base body 12, can be very advantageously manufactured in a single operation.
[0061] The film 30 has a similar thickness to the base layer body 44 and, as a plastic, has a similar heat capacity and a similar thermal conductivity, so that when the contact surface 18 is wetted with measuring fluid, the luminophore layer 36 on the surface 33 of the film 30 opposite the first section 20 of the contact surface 18 and the second section 28 of the coupling surface 24 have approximately the same temperature. This advantageously applies both in a quasi-steady state and in a transient situation, for example when the temperature of the measuring fluid changes at the contact surface 18 and the measuring fluid transmits this temperature change to the contact surface 18.
[0062] As can be seen in Figure 1, the first section 20 and the second section 22 of the contact surface 18 are arranged offset from one another not only in the longitudinal direction L as a possible reference direction, but also in a reference direction RD parallel to the contact surface 18, wherein the reference direction RD in the illustrated embodiment has its largest dimensional component in the longitudinal direction L.
[0063] In the embodiment of Figure 1, a recess 46 is formed in the luminophore base body 32, in which the film 30 is preferably received such that the first section 20 and the second section 22 of the contact surface 18 are arranged flush and lie in a common plane. The surface 27 of the radiation-emitting base body 12 facing the measuring fluid MF has a discontinuity at the transition to the recess 46.
[0064] Figure 2 shows a perspective view of a second embodiment of a radiation-emitting component according to the invention. Identical and functionally equivalent components and component sections as in the first embodiment shown in Figure 1 are provided with the same reference numerals in Figure 2, but increased by the number 100.
[0065] The second embodiment shown in Figure 2 is described below only insofar as it differs from the first embodiment of Figure 1, to whose description express reference is otherwise also made for explaining the second embodiment.
[0066] In the second embodiment, the foil 130 with the luminophore layer 136 is attached to the flat, crack- and kink-free surface 127 of the radiation-emitting component base body 112 by ultrasonic welding. The surface 127 in the region of the temperature detection area 116 forms part of the second section 122 of the contact surface 118. The first section 120 of the contact surface 118 is offset from the second section 122 by the thickness of the foil 130 and by the essentially negligible thickness of the luminophore layer 136 in the thickness direction D, i.e., in the direction of the axis 140 of the depth extension of the recess 138. Figure 3 shows a perspective view of a measuring cuvette 50 with the radiation-emitting component 10. Instead of the radiation emission component 10, which is chosen merely as an example, the measuring cuvette 50 could also have the radiation emission component 110.
[0067] The measuring cuvette comprises a cuvette housing 52, of which the radiation-emitting component 10 forms a part. The remaining cuvette housing 54, without the radiation-emitting component 10, is also made predominantly or entirely of MABS by weight and is preferably manufactured by injection molding. The IR-transparent windows 72 and 74, as well as their frame parts 77 and 78, are also preferably manufactured by injection molding. Because the materials are identical, the injection-molded portion of the remaining cuvette housing 54 can be simply molded onto the radiation-emitting component 10 to form the cuvette housing 52 without any further joining measures.
[0068] The cuvette housing 52 allows bidirectional flow along the flow path 56, which is preferably linear in the illustrated example. The cuvette housing 52 is designed for use in a ventilation line. It has a distal connection formation 58 and a proximal connection formation 60, to each of which additional sections of the ventilation line can be connected. In the intended installation position, a ventilation line section connected to the proximal connection formation 60 leads to the ventilated patient, and a ventilation line section connected to the distal connection formation 58 leads to the ventilation device.
[0069] Between the two connection formations 58 and 60 along the flow path 56, a coupling section 62 is formed with a coupling formation 64, which can be releasably coupled to the radiation-sensitive sensor arrangement 80 shown in Figures 6 and 7. The radiation-sensitive sensor arrangement 80 can be pushed astride the coupling section 62 along the arrow K1 and pulled off the coupling section 62 in the opposite direction along the arrow K2. A coupling structure 66 tapering from the proximal to the distal end on the lower side of the coupling section 62, in the direction of the arrow K1, prevents the coupling of an incorrectly oriented sensor arrangement 80 and also allows the sensor arrangement 80 to be releasably locked to the coupling section 62.
[0070] The distal connection formation 58 ends at a wall 59 oriented substantially orthogonally to the flow path 56, which separates the connection formation 58 from the coupling section 62. At its proximal longitudinal end, the coupling section 62 ends in a wall 61, from which the proximal connection formation 60 extends away from the coupling section 62.
[0071] In the illustrated embodiment, the radiation-emitting component 10 forms a ceiling section of the coupling section 62. Side walls 68 and 70 (see also Figure 5), oriented transversely, preferably orthogonally, to the ceiling section, each have a side window 72 and 74, respectively, permeable to infrared radiation, in order to allow infrared radiation to pass through a gas space 76 located inside the coupling section 62. This enables infrared spectroscopic detection of the carbon dioxide content, or in principle of another carbon dioxide-absorbing gas, of the measurement gas flowing in the gas space 76.
[0072] The viewer of Figure 4 looks along the flow path 56 from the distal longitudinal end of the measuring cuvette 50 into the gas chamber 76 thereof. The gas chamber 76 has a receiving volume 76a in which the measuring gas MF can be received, also as a flowing measuring gas MF.
[0073] Figure 5 shows a cross-section through the measuring cuvette 50 along a bent cutting plane, with a first plane section which extends orthogonally to the flow path 56 in the region of the radiation-emitting component 10 through its recess 38, and with a second plane section parallel to the first, which extends from the second section 22 of the contact surface through the centers of the circular side windows 72 and 74. The viewer of Figure 5 looks from the cutting surface in the direction of the distal connection formation 58. The side windows 72 and 74 are connected to frames 77 and 78, respectively, which are integrally connected to the rest of the cuvette housing 54 by injection molding. The contact surface 18 of the radiation-emitting component 10 forms a wall of the gas space 76, which delimits its receiving volume 76a at the top.
[0074] Figures 6 and 7 show a radiation-sensitive sensor arrangement 80 that can be releasably coupled to the measuring cuvette 50, more precisely to its coupling section 62. Figure 6 shows a perspective view of the sensor arrangement 80, and Figure 7 shows a bottom view of the same. The sensor arrangement 80 comprises a sensor housing 82 with a through-opening 84 surrounded by the sensor housing 82 on three sides, in which the coupling formation 62 of the measuring cuvette 50 is located when the sensor arrangement 80 is coupled to the measuring cuvette 50.
[0075] On that side of the sensor housing 82 which, when coupled to the measuring cuvette 50, points to the distal connection formation 58 of the measuring cuvette 50, an electrical line 85 is connected to the sensor housing 82, which electrical line 85 supplies electrical functional units accommodated in the sensor housing 82 with electrical current and also delivers control signals to the functional units and transmits detection signals from the functional units to a higher-level control device or evaluation device.
[0076] In the bottom view, such a functional unit can be seen as a sensor unit 86 that cooperates with the luminophore-containing region 14 of the radiation-emitting component 10 of the measuring cuvette 50. This sensor unit 86 comprises a radiation source 86a, which is designed to emit a first electromagnetic radiation as excitation radiation. The sensor unit 86 further comprises a radiation sensor 86b, which is designed to detect an excited second electromagnetic radiation emitted by the luminophore-containing region 14 in response to this excitation.
[0077] Furthermore, the bottom view shows an infrared sensor 88 as another such functional unit, which is designed to detect infrared radiation emitted by the second section 28 of the coupling surface 24. The sensor unit 86 and the infrared sensor are accommodated in a housing section 87 bridging the through-opening and, when coupled to the measuring cuvette 50, are located directly opposite the coupling surface 24 of the radiation-emitting component 10.
[0078] In the sensor housing region 90 of the sensor housing 82, located on one side of the through-opening 84, into which the electrical line 85 opens, an infrared radiation source 92 is accommodated as a third such functional unit. This source emits infrared radiation across the width of the through-opening 84 to the sensor housing region 94 opposite the sensor housing region 90 and located on the other side of the through-opening 84, where a second infrared sensor 96 is accommodated as a fourth such functional unit. The second infrared sensor 96 detects the infrared radiation emitted by the infrared radiation source 92 after passing through the two side windows 72 and 74 as well as through the gas space 76. This enables quantitative infrared spectroscopic determination of the carbon dioxide content of a gas flowing through the gas space 76.
Claims
Claims Radiation emission component (10; 100) for temperature-compensated optical detection of an oxygen content of a fluid (MF), wherein the radiation emission component (10; 100) comprises a contact surface (18; 118) wettable by the fluid (MF) and a coupling surface (24; 124) different from the contact surface (18; 118) for coupling to a radiation-sensitive sensor arrangement (80), wherein the radiation emission component (10; 100) has a luminophore-containing region (14; 114), wherein an excited emission behavior of the luminophore in the luminophore-containing region (14; 114) is dependent on an oxygen partial pressure in a fluid (MF) wetting the contact surface (18; 118), and wherein the luminophore is arranged in a first section (20; 120) of the contact surface (18; 118) of oxygen, wherein the radiation emission component (10; 110) has a temperature detection area (16; 116) emitting infrared radiation, wherein the temperature detection area (16;116) is arranged offset relative to the luminophore-containing region (14; 114) in a reference direction (RD) along the contact surface (18; 118), and wherein the radiation-emitting component (10; 110) has, in the section in which the temperature-detecting region (16; 116) is arranged, a base body (34; 134) with a recess (38; 138) extending towards the contact surface (18; 118), wherein the recess (38; 138) is covered by a base (42; 142) comprising a base layer body (44; 144), wherein a surface of the base layer body (44; 144) facing away from the recess (38; 138) forms a second section (22; 122) of the contact surface, which is different from the first section (20; 120). (18; 118), characterized in that the base body (34; 134) and the base layer body (44; 144) each comprise plastic material, wherein the base body (34; 134) and the base layer body (44;144) are integrally connected to one another by means of their respective plastic materials.; Radiation-emitting component (10; 110) according to claim 1, characterized in that the plastic material of the base body (34; 134) and the plastic material of the base layer body (44; 144) are partially fused to one another, or the base body (34; 134) and the base layer body (44; 144) are formed monolithically from the same plastic material. Radiation-emitting component (10; 110) according to claim 1 or 2, characterized in that the base layer body (44; 144) is formed entirely from the plastic material. Radiation-emitting component (10; 110) according to one of the preceding claims, characterized in that the base layer body (44; 144) is thinner than the base body (34; 134) surrounding the recess (38; 138).Radiation-emitting component (10; 110) according to one of the preceding claims, characterized in that the plastic material of the base layer body (44; 144) has a transmittance of no more than 20% for infrared radiation in a wavelength range from 5500 nm to 14000 nm. Radiation-emitting component (10; 110) according to claim 5, characterized in that the plastic material of the base layer body (44; 144) has a transmittance of no more than 5% for infrared radiation in the wavelength range, wherein the plastic material of the base layer body (44; 144) forms the surface (47; 147) of the base (42; 142) facing the recess. Radiation emission component (10; 110) according to one of claims 1 to 5, characterized in that the base layer body (44; 144) on its surface (47; 147) facing away from the contact surface (18; 118) and / or. carries a coating on its surface facing the contact surface (18; 118), wherein the base (42; 142) has an absorption factor of at least 95% and / or an emission factor of at least 95% in the direction of the recess (38; 138) in the wavelength range from 5500 nm to 14000 nm.
8. Radiation-emitting component (10; 110) according to one of the preceding claims, characterized in that the radiation-emitting component (10; 110) has a luminophore base body (32; 132), wherein the luminophore base body (32; 132) carries an oxygen-permeable film (30; 130), wherein a first surface of the film (30; 130) forms the first section (20; 120) of the contact surface (18; 118) of the radiation-emitting component (10; 110).
9. Radiation-emitting component (10; 110) according to claim 8, characterized in that the luminophore base body (32; 132) has a transmittance of at least 80% for radiation in a first wavelength range from 450 to 480 nm and in a second wavelength range from 730 to 1100 nm.
10. Radiation-emitting component (10; 110) according to claim 9, characterized in that the base body (34; 134) and the luminophore base body (32; 132) are formed in one piece and monolithically as a radiation-emitting component base body (12; 112), of which the base body (34; 134) and the luminophore base body (32; 132) each form a section.
11. Radiation-emitting component (10; 110) according to claim 10, characterized in that the reference direction (RD) in a Cartesian coordinate system comprising longitudinal direction (L), width direction (B) and thickness direction (D) is the longitudinal direction (L) of the radiation-emitting component (10; 110) in which the radiation-emitting component (10; 110) has its largest dimension among said Cartesian coordinate directions.
12. Measuring cuvette (50) with a radiation emission component (10; 110) according to one of the preceding claims, wherein the measuring cuvette (50) has a gas space (76) with a receiving volume (76a) for receiving a measuring gas (MF), wherein the contact surface (18; 118) forms a wall of the gas space (76) delimiting the receiving volume (76a) and exposed to the receiving volume (76a), and wherein at least a portion (26, 28; 126, 128) of the coupling surface (24; 124) is exposed to the outside environment of the measuring cuvette (50).
13. Measuring cuvette (50) according to claim 12, characterized in that at least one boundary wall (68, 70) of the gas space (76) has a window (72, 74) permeable to radiation in the infrared wavelength range.
14. Measuring cuvette according to claim 12 or 13, characterized in that the gas space (76) can be flowed through by measuring gas (MF) along a flow direction (56), wherein the radiation emission component (10; 110) is located in the flow direction (56) between two connection formations (58, 60), wherein each of the connection formations (58, 60) is designed to connect a line carrying measuring gas (MF).
15. Sensor device comprising a measuring cuvette (50) according to one of claims 12 to 14 and further comprising a radiation-sensitive sensor arrangement (80) with a sensor housing (82) in which is accommodated: a radiation source (86a) for emitting the first electromagnetic radiation, a first radiation sensor (86b) for detecting the second electromagnetic radiation and at least one infrared sensor (88) for detecting infrared radiation in a wavelength range for which the bottom (42; 142) of the temperature detection area (16; 116) has a transmittance of not more than 20%, wherein the sensor housing (82) is detachably attachable to a section (62) of the measuring cuvette (50) having the radiation emission component (10).