MEASUREMENT DEVICE THROUGH WHICH BREATHING GAS CAN FLOW FOR MEASURING GAS COMPONENTS OF THE BREATHING GAS

Abstract

The invention relates to a measurement device for determining at least one gas component of a gas present in a measuring chamber of the measuring device, the measuring device comprising a housing enclosing the measuring chamber, at least one housing wall section of which housing being designed as an observation section for detecting electromagnetic radiation emanating from the observation section in a direction away from the measuring chamber, the observation section comprising at least one film layer, and the housing being designed as a plastic injection-moulded housing. The invention is characterised in that the observation section has at least one observation wall component comprising an injection-moulded observation body injection-moulded onto the at least one film layer, and the housing comprises the at least one observation wall component and an injection-moulded frame body injection-moulded onto the observation wall component.

Claims

1. A measuring device for measuring at least one gas constituent of a gas present in a measuring chamber of the measuring device, where the measuring device comprises: a housing surrounding the measuring chamber, of which at least one housing wall section is configured as an observation section for the acquisition of electromagnetic radiation emitted from the observation section in a direction away from the measuring chamber, where the observation section comprises at least one foil layer and where the housing is configured as a synthetic material injection molded housing, wherein the observation section exhibits at least one observation wall component, comprising an observation injection-molded body injected onto the at least one foil layer, where the housing comprises the at least one observation wall component and a frame injection-molded body injected onto the observation wall component.

2. The measuring device according to claim 1, wherein the measuring chamber allows the flowthrough of gas along a virtual flow path.

3. The measuring device according to claim 1, wherein the observation injection-molded body exhibits an observation cutout, within which the at least one foil layer is accessible.

4. The measuring device according to claim 3, wherein a lateral face of the observation cutout tapers in a direction towards at least one foil layer and thus is configured as a centering surface for tool engagement.

5. The measuring device according to claim 1, wherein the at least one foil layer is transparent to electromagnetic radiation in the infrared spectral range.

6. The measuring device according to claim 5, wherein the at least one foil layer comprises a biaxially oriented polymer foil.

7. The measuring device according claim 1, wherein it comprises a first and a second first gas constituent observation wall component, which are provided for capturing a first gas constituent at the housing in such a way that at least one section of the measuring chamber is located between them, where the first and the second first gas constituent observation wall component are arranged in such a way at the housing that electromagnetic radiation which is radiated into the measuring chamber through an observation section of one of the two first gas constituent observation wall components, can radiate out of the measuring chamber through the observation section of the respectively other first gas constituent observation wall component.

8. The measuring device according to claim 1, wherein the at least one foil layer comprises as a temperature measurement foil layer a metal foil.

9. The measuring device according to claim 1, wherein the at least one foil layer exhibits as second gas constituent foil layer for capturing a second gas constituent differing from the first one a photoluminescent layer with at least one luminophore accommodated in it.

10. The measuring device according to one of the claims 8 and 9, wherein it exhibits a second gas constituent observation wall component with the second gas constituent foil layer, which also exhibits the temperature measurement foil layer.

11. The measuring device according to one of the claim 9 or 10, wherein the second gas constituent foil layer is covered completely by the observation injection-molded body on its side facing away from the measuring chamber, where the observation injection-molded body is transparent to electromagnetic radiation in the wavelength range of the photoluminescent radiation emitted from the photoluminescent layer.

12. The measuring device according to claim 1, having regard to claims 7 and 9, wherein it exhibits both the first and the second first gas constituent observation wall component and a second gas constituent observation wall component with the second gas constituent foil layer, where at the housing the first and the second first gas constituent observation wall component are each arranged at a different side of the second gas constituent observation wall component.

13. The measuring device according to claim 1, wherein at least at one longitudinal end of the housing, preferentially at two opposite longitudinal ends, a connector formation is arranged at each which is configured for connecting a hose and/or pipe line.

14. An bservation wall component for a measuring device, said measuring device comprising a housing surrounding the measuring chamber, of which at least one housing wall section is configured as an observation section for the acquisition of electromagnetic radiation emitted from the observation section in a direction away from the measuring chamber, where the observation section comprises at least one foil layer and where the housing is configured as a synthetic material injection molded housing, wherein the observation section exhibits at least one observation wall component, comprising an observation injection-molded body injected onto the at least one foil layer, where the housing comprises the observation wall component and a frame injection-molded body injected onto the observation wall component wherein the observation wall component exhibits at least one foil layer with observation injection-molded bodies injected onto it, where the at least one foil layer exhibits a photoluminescent layer with at least one luminophore accommodated in it and/or where the observation injection-molded body exhibits an observation cutout, within which the at least one foil layer is accessible, where one lateral face of the observation cutout tapers in a direction towards at least one foil layer and thus is configured as a centering surface for tool engagement.

15. A method for fabricating an observation section of a measuring device for measuring a gas constituent of a gas present in a measuring chamber of the measuring device, where the measuring chamber is surrounded at least in part by the observation section, the method comprising the following steps: inlaying of a foil body with at least oner foil layer in an injection-molding cavity, injection of an observation injection-molded body onto the foil body and thereby forming an observation wall component, and injection of a second injection-molded synthetic body onto the observation wall component and thereby fabricating the observation section.

16. The measuring device according to claim 5, wherein the at least one foil layer comprises a biaxially oriented polyolefin foil.

17. The measuring device according to claim 5, wherein the at least one foil layer comprises a biaxially oriented polypropylene foil.

18. The measuring device according to claim 1, wherein the at least one foil layer comprises as a temperature measurement foil layer a metal foil coated with black material.

19. The measuring device according to claim 1, wherein the at least one foil layer comprises as a temperature measurement foil layer a aluminum foil coated with black material.

20. The measuring device according to claim 1, wherein at at two opposite longitudinal ends, a connector formation is arranged at each which is configured for connecting a hose and/or pipe line.

Description

[0079] The present invention is described in more detail below with the help of the enclosed drawings. They show:

[0080] FIG. 1A perspective view of an embodiment according to the invention of a measuring device of the present application,

[0081] FIG. 2 The measuring device of FIG. 1 in an exploded view in perspective,

[0082] FIG. 3A top view of the measuring device of FIGS. 1 and 2,

[0083] FIG. 4A sectional view through the measuring device of FIGS. 1 to 3 along the section plane A-A of FIG. 3,

[0084] FIG. 5A sectional view of the measuring device of FIGS. 1 to 4 along the section plane B-B of FIG. 3,

[0085] FIG. 6A view of the measuring device of FIGS. 1 to 5 along the flow path in the direction of an expiratory respiratory gas flow,

[0086] FIG. 7A sectional view through the measuring device of FIGS. 1 to 6 along the section plane C-C of FIG. 6, and

[0087] FIG. 8A sectional view of a second embodiment of a measuring device corresponding to the view of FIG. 5.

[0088] In FIGS. 1 to 7, an embodiment according to the invention of a measuring device is denoted generally by 10. The measuring device 10 serves to measure at least one gas constituent of a gas flowing through the measuring device 10. The measuring device 10 comprises a synthetic housing 12, through which flow is possible bidirectionally along a virtual flow path SB which in the depicted example is preferentially straight-lined.

[0089] The housing 12 comprises a central observation region 14, a distal connector formation 16 for connecting a gas line, in particular a ventilation hose, and a proximal connector formation 18 for connecting a gas-carrying line, in particular a ventilation hose or ventilation tube.

[0090] The measuring device 10, configured for use in a ventilation hose arrangement of a ventilation device for artificial ventilation of patients, is normally connected with the distal connector formation 16 with the respiratory gas source of the ventilation device and is connected via the proximal connector formation 18 with the patient to be ventilated.

[0091] The housing 12 exhibits a frame injection-molded body 20 and in the present example three observation wall components 22, 24, and 26, of which in FIG. 1 only the observation wall components 24 and 26 can be discerned.

[0092] FIG. 2 shows an exploded view in perspective of the measuring device 10 of FIG. 1.

[0093] FIG. 2 shows also the observation wall component 22 that is not discernible in FIG. 1. Likewise it is discernible that the frame injection-molded body is a component formed integrally through injection molding, at which the connector formations 16 and 18 are configured.

[0094] The two observation wall components 22 and 24 serve at the measuring device 10 for the measurement of CO.sub.2 as a first gas constituent. They are, therefore, first gas constituent observation wall components 22 and 24. They are preferentially configured as mirror-imaged relative to a plane orthogonal to the flow path SB, such that each wall component 22 and 24 can be used as a first gas constituent observation wall component of the measuring device 10 on each side of the frame injection-molded body 20. Each of the two first gas constituent observation wall components 22 and 24 exhibits a foil body 28 or 30 respectively, which is made from BOPP or at least exhibits a BOPP layer on its side that faces away from the flow path SB.

[0095] The foil body 28 is shown in detail as an example and not to scale. In the depicted example, the foil body 28 comprises, from the outside inwards, a protective foil 28a preferentially made from polycarbonate, an adhesion-mediating layer 28b, preferentially made from pure acrylate adhesive, and a BOPP foil layer 28c. The foil body 30 can be constructed identically to foil body 28. Differently from the depiction, the foil body 28 can exhibit just one foil layer. Then the foil body 28 can be constructed identically to the foil body 30 shown as an example.

[0096] An observation injection-molded body 32 is injected onto the polycarbonate layer 28a of the foil body 28. An observation injection-molded body is injected onto the BOPP layer of the foil body 30. To this end, the foil bodies 28 and 30 are inserted respectively into an injection-molding cavity and then the observation injection-molded bodies 32 and 34 injected onto the foil body 28 or 30 respectively in an injection molding process.

[0097] Each of the observation injection-molded bodies 32 and 34 exhibits a cutout 36 or 38 respectively that passes through it in the thickness direction, which is covered at its end that is located nearer to the virtual flow path SB by the respectively assigned foil body 28 or 30 respectively.

[0098] A lateral face 36a of the observation cutout 36 and a lateral face 38a of the observation cutout 38 are each configured as tapering, preferentially conically, towards the foil body 28 or 30, such that each lateral face 36a and 38a can respectively serve as a centering surface for the arrangement of the wall component 22 or 24 respectively in an injection-molding cavity for fabrication of the frame injection-molded body 20. The wall component 22 can then be centered by reference to its lateral face 36a and the wall component 24 by reference to its lateral face 38a. Hereby a very accurate arrangement of the wall components 22 and 24 in the injection-molding cavity for fabrication of the frame injection-molded body 20 is possible.

[0099] Due to the preferentially mirror-symmetrical configuration to a plane orthogonal to the virtual flow path SB, the cutouts 36 and 38 in the depicted embodiment are located in the longitudinal middle of the observation injection-molded body 32 or 34 respectively relative to the virtual flow path SB.

[0100] To facilitate their arrangement at frame injection-molded body 20 and in particular for arrangement in the injection-molding cavity for fabrication of the frame injection-molded body 20, the observation injection-molded body 32 and 34 each exhibit at their respective lower ends as shown in FIGS. 1 and 2 an alignment formation 32b or 34b respectively.

[0101] Although FIG. 2 shows an exploded view of the measuring device 10, it should be understood that due to the injection of the frame injection molding body 20 onto the observation wall components 22, 24, and 26 the measuring device 10 thus formed can no longer be disassembled, but rather that frame injection-molded body 20 and the observation wall components 22, 24, and 26 form an essentially firmly bonded unit.

[0102] The first gas constituent observation wall components 22 and 24 each exhibit both on their side that in the finished installed state faces towards the virtual flow path SB, at which the foil bodies 28 or 30 respectively are located, and on their external side facing away from the virtual flow path SB, which is formed by an external side of the observation injection molding body 32 or 34 respectively, a plane outer surface each.

[0103] The wall component 26 serves in the depicted embodiment for measuring an O.sub.2 fraction in the gas flowing through the measuring device 10. The wall component 26 is therefore in distinction from the first gas constituent observation wall components 22 and 24 a second gas constituent observation wall component 26 in terms of the present application and exhibits an observation injection-molded body 40, which in the thickness direction has a cutout 42 passing through it.

[0104] The observation injection-molded body 40, like the other two observation injection-molded bodies 32 and 34, injected by means of injection molding onto a foil body, here the foil body 44.

[0105] In contrast to the foil bodies 28 and 30, which can comprise just a single BOPP layer, the foil body 44 is multilayered. The foil bodies 28 and 30, however, can also be configured as multilayered.

[0106] The foil layer of the foil body 44 lying next to the observation injection-molded body 40 is a BOPP foil layer 46. The BOPP foil layer 46 exhibits there a cutout 48 passing through it, where after the injection of the observation injection-molded body 40 its cutout 42 is located.

[0107] On the side of the BOPP foil 46 facing away from the observation injection-molded body 40 there is located a luminophore-containing foil 50 in a region of the BOPP foil 46 lying nearer to the proximal connector formation 18. The luminophore in the luminophore-containing foil layer 50 can be excited through the preferentially transparent observation injection-molded body 40 to radiate electromagnetic radiation, in particular light, and can be observed through the observation injection-molded body 40 in its excited radiation behavior.

[0108] Oxygen in the gas flowing through the measuring device 10 along the virtual flow path SB comes into contact with the excited luminophore of foil layer 50, whereby the luminophore is quenched, i.e. ‘de-excited’, and consequently its radiation behavior changes as a function of the oxygen concentration in the gas flowing through the measuring device 10.

[0109] In a section of the foil body 44 lying nearer by the distal connector formation 16, it exhibits on a side of the BOPP foil layer 46 facing away from the observation injection-molded body 40 a metal foil 52, which on its side facing towards the BOPP foil layer 46 and consequently towards the observation injection-molded body 40 is coated with black varnish 54.

[0110] The metal foil 52 coated with black varnish 54 consequently forms a temperature measurement foil layer, which is observable through the cutout 42. The metal foil 52, preferentially an aluminum foil 52, with likewise preferentially a material thickness in the single-digit pm range, due to its good heat conductance adopts the temperature of the gas flowing through the measuring device 10 along the virtual flow path SB. The black varnish 54 emits thermal radiation characteristic of the temperature of the metal foil 52 through the cutout 42 towards the outside, where it is observable as infrared radiation. In this way the temperature of the gas flowing through the measuring device 10 can be measured. The wall component 26 is, therefore, also a temperature observation wall component 26.

[0111] Through the cutouts 36 and 38, the measuring device 10, again more accurately a measuring chamber 56 in the interior of the measuring device 10 surrounded by the observation wall components 22, 24, and 26, can be penetrated by infrared rays. To this end, infrared radiation is sent with an external infrared radiation source through one of the cutouts 36 or 38 into the measuring chamber 56 in such a way that the infrared radiation is observable through the respective other cutout. The infrared spectroscopic method that can be used to measure the carbon dioxide content of the respiratory gas is sufficiently known.

[0112] Since the two observation wall components 22 and 24 are essentially constructed identically, each of the two wall components 22 and 24 can be used to send infrared radiation into the measuring chamber 56 and the respective other to observe the infrared radiation emerging from the measuring chamber 56 after passing through it.

[0113] Therefore, the first first gas constituent observation wall component 22 forms an observation section 58 and the second first gas constituent observation wall component 24 an observation section 60.

[0114] The observation wall component 26 comprises in contrast two separate observation sections, namely an observation section 62 for observing the radiation behavior of the luminophore of the luminophore-containing foil layer 50 and a temperature observation section 64 in the region of the cutout 42 for observing the thermal radiation emitted from the temperature measurement foil layer 52 with varnish application 54 for determining the temperature of the gas flowing through the measuring device 10. It is also possible for just one of the observation sections 62 and 64 to be provided.

[0115] Furthermore, the lateral face 42a of the cutout 42 in the observation injection-molded body 26 is also configured as tapering conically from outside towards the foil arrangement 44, in order to be able to arrange the observation wall component 26 that is usable both for temperature measurement and for measuring the oxygen content positioned accurately and centered in the injection-molding cavity for fabrication of the frame injection-molded body 20.

[0116] The observation injection-molded body 40 of the observation wall component 26 is bounded by a plane surface both on its side that faces towards the measuring chamber 56 and also on its external side that faces away from the measuring chamber 56. Preferentially, the two plane boundary areas are parallel to each other. This also applies to the aforementioned observation injection-molded body 32, 34. Due to differing layer thicknesses of the metal foil 52 provided with the black varnish layer 54 on the one hand and the luminophore-containing foil layer 50 on the other, the boundary area of the observation wall component 26 facing towards the measuring chamber 56 can exhibit two, preferentially plane, area sections which are offset relative to each other in a direction orthogonal to the flow path SB.

[0117] In the sectional view of FIG. 4, in which the observer looks through the measuring chamber 56 towards the BOPP foil layer 30, the foil body 44 of the observation wall component 26 is discernible in top view.

[0118] One can discern in particular that the foil body 44 does not have to exhibit uniform thickness. For example, in the region of the luminophore-containing foil layer 50 it can be configured as thicker than in the region of the temperature measurement foil layer 52 with the black coating 54 on it.

[0119] It is discernible in FIG. 5 how many surfaces of the observation wall parts 22, 24, and 26 are wetted by surfaces of the frame injection-molded body 20 during injection molding fabrication of the frame injection-molded body 20, such that firm bonding is produced between the observation injection-molded bodies 32, 34, and 40 that preferentially are produced from at least compatible, preferentially identical synthetics on the one hand and the frame injection-molded body 20 on the other. In particular the alignment formations 32b and 34b of the observation injection-molded bodies 32 or 34 respectively exhibit a large area wetted by the frame injection-molded body 20, which is even angled and encompasses an outer surface of the alignment formations 32b and 34b.

[0120] FIG. 5 depicts the virtual cutout axes 70, 72, and 74 of the cutouts 36, 38, and 42 respectively. The cutouts 36, 38, and 42 taper along the virtual cutout axes 70, 72, and 74 respectively that pass through them centrally from outside the measuring chamber 56 in the direction towards the measuring chamber 56. The cutout axes 70, 72, and 74 can be conus axes of the conical lateral faces 36a, 38a, and 42a of the relevant cutouts 36, 38, and 42 respectively, for instance if the respective lateral faces are configured as rotation-symmetrical.

[0121] Since the two observation sections 58 and 60 are configured for trans-irradiation of the measuring chamber 56 arranged between them, preferentially the associated cutout axes 70 and 72 are collinear.

[0122] As FIG. 5 further shows, the second gas constituent wall component 26 is located between the two first gas constituent observation wall components 22 and 24, or in other words: The first gas constituent observation wall components 22 and 24 are each located on different sides of the second gas constituent observation wall component 26. Preferentially the extension regions of the wall components 22, 24, and 26 overlap along the virtual flow path SB, such that the measuring chamber 56 can be configured to be short along the flow path SB.

[0123] In FIG. 5 it is further discernible how the outer surfaces of the observation injection molding components 32, 34, and 40 that face away from the measuring chamber 56 are configured as planar and are arranged parallel or at a right angle to each other. The crosspieces 20a and 20b of the frame injection-molded body 20 in the region of the measuring chamber 56 running parallel to the flow path SB, arranged between each of the first gas constituent observation wall components 22 or 24 respectively on the one hand and the second gas constituent observation wall component 26 on the other, connect flush with their outer surfaces with the outer surfaces of the wall components 22, 24, and 26, such that a measurement device coming from the side of the wall component 26 in the observation region 14 of the measuring device 10 orthogonally to the virtual flow path SB can be pushed onto same. Such a measuring device can exhibit an infrared radiation source and an infrared sensor located opposite to this source in a direction orthogonal to the virtual flow path SB. Furthermore, the measuring device can exhibit between the infrared radiation source and the infrared sensor an excitation radiation source for excitation of the luminophore in the luminophore-containing foil layer 50 and a capture device provided for observing the quenching behavior of same. Likewise, a further infrared sensor for capturing the thermal radiation emitted from the temperature measurement foil layer 52 can be arranged therein. Such a measuring device can simply be pushed onto the observation region 14 of the measuring device 10 and again removed from it.

[0124] FIG. 7 shows a sectional view through the measuring device 10 along the section plane C-C of FIG. 6. The two foil bodies 28 and 30 are aligned parallel to the virtual flow path SB and parallel to each other.

[0125] FIG. 8 shows a sectional view of a second embodiment of a measuring device 110 in the section plane B-B of FIG. 3, however in the opposite direction of view towards the section plane B-B to the one indicated in FIG. 3. Basically, the view of FIG. 8 corresponds in the section plane to the depiction of FIG. 5. Identical and/or functionally identical components and component sections as in the first embodiment of FIGS. 1 to 7 are provided in FIG. 8 with the same reference labels, but increased numerically by 100.

[0126] The second embodiment of FIG. 8 will only be described hereunder in so far as it differs from the first embodiment of FIGS. 1 to 7 whose description otherwise also applies to the second embodiment of FIG. 8.

[0127] A rather insignificant difference consists in the fact that the observation injection-molded bodies 132 and 134 do not exhibit alignment formations at their end regions distal to the observation wall component 126.

[0128] In the observation cutouts 136 and 138, instead of foil bodies there are present window components 128 or 130 respectively made of glass. The window components 128 and 130 are configured identically and merely arranged in the measuring device 110 mirror-inverted relative to each other by reference to a mirror-symmetry plane spanned by the flow path SB and the cutout axis 174. The window components 128 and 130 exhibit in the depicted example a circular circumference.

[0129] This, however, need not be the case. The window components 128 and 130 can alternatively exhibit an oval or a polygonal circumference.

[0130] Due to their identical configuration, it suffices to describe the window component 128 in more detail hereunder. Its description also applies to the window component 130, allowing for the aforementioned mirror symmetry.

[0131] The window component 128 exhibits a central window section 180, which in the described example exhibits an essentially cylindrical shape, where preferentially the cutout axis 170 is the cylindrical axis of the window section 180.

[0132] Running completely around the window section 180, the window component 128 exhibits an anchor projection 182 protruding radially from the window section 180, which exhibits a lower thickness than the window section 180. The anchor projection 182 is surrounded along its entire circuit around the cutout axis 170 on three sides by U-shaped material of the observation injection-molded body 132. The window component 180 with its anchor projection 182 was extrusion-coated by same during the injection molding fabrication of the observation injection-molded body 132. As a result, both mechanically firm and gas-tight bonding of the window component 128 with the observation injection-molded body 132 was achieved.

[0133] The window components 128 and 130 are made in the present case of sapphire glass or chalcogenide glass, i.e. they consist either of aluminum oxide or of germanium.

[0134] The inner surface of window section 180 of window component 128 is arranged flush with the inner surface of the observation injection-molded body 132. As a result, steps at the inner walls bounding the measuring chamber 156 are avoided, at which otherwise moisture could undesirably condense.

[0135] The anchor projection 182 forms together with the window section 180 a plane outer surface of the window component 128.