Photoacoustic detection device

Abstract

The photoacoustic detection device (1) for measuring a parameter of interest in a medium comprises: a housing (7) with a base plate (72) and a cover (71); a light source (2) for emitting an optical signal; a photoacoustic cell (9) with a hollow contact surface (91) for contacting the medium, the optical signal propagating from a guide element (8) within the photoacoustic cell (9) to reach the medium; a transducer (3) coupled to the photoacoustic cell (9) and configured to detect the emitted signal; and a first holding element (100) configured to assemble the light source (2) and the guide element (8) into a building block, the building block being accommodated in the housing (7). The photoacoustic cell (9) is reversibly attached to the construction block by at least one fixing element (95) accessible from outside the housing (7), the size of the photoacoustic cell (9) is such that the photoacoustic cell (9) can be removed from the housing (7) as needed by passing it through an opening (721) in the base plate (72), the transducer (3) is reversibly coupled to the construction block and positioned between the construction block and the photoacoustic cell (9), and the transducer (3) can be removed from the opening (721) in the base plate (72) simultaneously with or after the photoacoustic cell (9) is removed from the housing (7).

Description

[Technical Field]

[0001] The present invention relates to an optical sound detection device for measuring a parameter of interest in a medium. [Background technology]

[0002] Photoacoustic detection can be used in the field of sensing devices, in particular to detect parameters of interest such as chemical constituents in a medium, which may be organic tissue such as human skin.

[0003] Photoacoustic detection is based on the illumination of the analyzed medium M by an optical signal emitted by a light source. Typically, the light source is one or more lasers, in particular quantum cascade lasers (QCLs). The optical signal is a light beam of a selected wavelength. The wavelength is selected depending on the type of parameter of interest to be measured.

[0004] Photoacoustic detection is based on the detection of pressure waves associated with thermal waves. Thermal waves are generated under the influence of the absorption of a light beam by a medium. Such absorption causes local heating of chemical components in the medium that absorbed the light beam. The thermal waves propagate through the medium M and then out of the medium. More precisely, after propagation of the thermal waves, as they leave the medium, pressure waves are generated that can be detected.

[0005] Photoacoustic detection can be made specific to a particular chemical component by adjusting the wavelength and / or modulation frequency of the light beam. More precisely, the wavelength can be adjusted to match the absorption peak of the component being analyzed.

[0006] As a result, photoacoustic detection is a method for non-invasively analyzing a medium of interest. Numerous photoacoustic detection devices have been developed.

[0007] Such photoacoustic detection devices generally include a photoacoustic cell, a light source that emits a light beam, a guide element that directs the light beam to the photoacoustic cell, and at least one transducer that can detect a signal generated in the photoacoustic cell by the photothermal effect of the medium in response to irradiation of the medium by the light beam. Summary of the Invention [Problem to be solved by the invention]

[0008] The main drawback of such photoacoustic devices is that they are conceived as a single monolithic block, including the photoacoustic cell, light source, guide elements, and transducer. Such a detection device requires the replacement of the entire block if, for example, one of the elements fails and needs to be replaced, or if a parameter of interest needs to be measured according to different characteristics induced by the structure of the photoacoustic cell. In other words, the entire detection device must be replaced.

[0009] SUMMARY OF THE INVENTION The present invention therefore aims to at least partially solve the above-mentioned problems. [Means for solving the problem]

[0010] The present invention therefore relates to an optical sound detection device for measuring a parameter of interest in a medium, the optical sound detection device comprising: a housing having a base plate and a cover; a light source configured to emit an optical signal; an optoacoustic cell including a contact surface emerging from an opening in the base plate, said contact surface being intended to be in contact with a medium, and an optical signal being able to propagate in the optoacoustic cell and pass through the contact surface to reach the medium; a guide structure configured to guide the optical signal to the photoacoustic cell; a transducer coupled to the photoacoustic cell and configured to detect an generated signal, the generated signal being generated within the photoacoustic cell by a photothermal effect in the medium in response to illumination of the medium with an optical signal; a first holding element configured to assemble the light source and the guide element into a construction block, the construction block being accommodated in a housing; and Equipped with the photoacoustic cell is reversibly attached to the construction block by at least one fixing element accessible from outside said housing, and the size of the photoacoustic cell is such that the photoacoustic cell can be removed from the housing, if necessary, by passing through an opening in the base plate; The transducer is reversibly coupled to the building block and positioned between the building block and the photoacoustic cell, such that the transducer can be removed through the opening in the base plate simultaneously with or after the photoacoustic cell is removed from the housing.

[0011] The proposed detection device allows for simple and easy disassembly of the photoacoustic cell and / or the transducer when necessary. Indeed, since the fixing elements are accessible from the outside of the housing, the photoacoustic cell can be removed directly through the opening in the base plate, without the need to remove a cover or open the housing. The other components are very well protected by this particular configuration. Furthermore, since the transducer is reversibly coupled to the building block and is located between the building block and the photoacoustic cell, the transducer can also be removed from the housing without opening it when the photoacoustic cell is removed from the housing, or at the same time the photoacoustic cell is removed from the housing.

[0012] Disassembly of the photoacoustic cell and / or transducer may be necessary to clean the photoacoustic cell and / or transducer, or to replace the photoacoustic cell and / or transducer with another photoacoustic cell or transducer, which may be the case if one of these two components fails, or if an photoacoustic cell or transducer with different characteristics is required for analysis of the parameter of interest.

[0013] According to one embodiment, the transducer is attached to a second holding element, the second holding element comprising a connection portion with respect to the first holding element, the connection element being configured to reversibly connect said connection portion of said second holding element to the first holding element, so as to ensure a mechanical, electronic and / or electrical connection between the transducer and the building block.

[0014] Generally, the transducer must be permanently connected to a component that allows for the analysis of the generated detection signal. Such connection means are, for example, a wire or brazing of the transducer. In the present application, a connecting element ensures the connection of the transducer to such an analysis component, while at the same time allowing for easy disassembly of the transducer from the detection device, if necessary. More specifically, the connecting element allows for a mechanical connection between the transducer and a building block so that the transducer does not move around inside the housing, and / or allows for an electronic connection between the transducer and a building block that holds components for analyzing the generated signal detected by the transducer, and / or allows for an electrical connection between the transducer and the building block.

[0015] According to one embodiment, removing the transducer outside the housing includes removing the transducer and the second retaining element.

[0016] If the user needs to remove or clean the transducer, this means that the same or a new transducer must be replaced. However, when the housing is closed, it can be difficult to properly position and secure the transducer within the housing. In fact, if the transducer is not properly positioned, it may not be possible to properly detect the generated signal.

[0017] The object of this application is to allow the transducer to be replaced without the need to disassemble the entire detection device.

[0018] Thanks to this particular configuration, if a user needs to replace the transducer, they actually need to replace the assembly made up of the transducer and the second holding element. This assembly is much easier to replace than the transducer, thanks to the connecting portion of the second holding element arranged in relation to the connecting element. As a result, the user can find when the second holding element, and therefore the transducer, is in a good position.

[0019] According to one embodiment, the connecting element is brazed onto the first holding element.

[0020] Since the connecting element is permanently mounted in the detection device, it is easy for the user to position the assembly made up of the transducer and the second holding element.

[0021] According to one embodiment, the connection element is a leaf spring connector.

[0022] Leaf springs are used as components in the electronics industry, making them easy to manufacture, and leaf spring connectors are generally inexpensive.

[0023] According to one embodiment, the fixing of the photoacoustic cell to the detection device by the fixing element is configured to press the second holding element against the connecting element.

[0024] This configuration therefore ensures a good connection of the transducer to the building block via the connecting element.

[0025] More precisely, the optoacoustic cell comprises an extension in contact with the second holding element and surrounding the transducer, said extension pressing the second holding element against the connecting element.

[0026] According to one embodiment, the photoacoustic cell comprises an extension reversibly attached to the second holding element, said extension surrounding the transducer.

[0027] By virtue of this configuration, the photoacoustic cell can be removed from the detection device without having to remove the transducer. This can be particularly advantageous if the user needs to replace one of the components. Indeed, if the user needs to replace only one of the transducer and the photoacoustic cell, they can simply put a new transducer and replace the old photoacoustic cell (or vice versa) without having to replace both the transducer and the photoacoustic cell.

[0028] According to one embodiment, the extension of the photoacoustic cell comprises a stud configured to cooperate with a hole provided in the second holding element.

[0029] This configuration makes it easier to place the photoacoustic cell back into the detection device. Since a tight seal between the photoacoustic cell and the transducer must be ensured to allow good photoacoustic detection, the studs and holes allow the user to know exactly when the photoacoustic cell is in the correct position within the detection device. This is particularly useful when only the photoacoustic cell needs to be removed and replaced from the detection device.

[0030] According to one embodiment, the photoacoustic cell comprises an extension permanently attached to the second holding element, said extension surrounding the transducer.

[0031] Thanks to this configuration, the photoacoustic cell and the transducer are removed together from the detection device, which can be particularly advantageous if the user needs to clean the two components, as it only requires one step to remove the transducer and the photoacoustic cell.

[0032] According to one embodiment, the photoacoustic cell is attached to the second holding element by means of an adhesive, such as double-sided tape.

[0033] According to one embodiment, the fixing element reversibly attaching the photoacoustic cell to the building block is a screw-fastening element, the head of which is accessible from outside the housing.

[0034] The skirt can improve user comfort and hide the fixing elements of the photoacoustic cell.

[0035] The present application also relates to an optical sound detection device kit including an optical sound detection device according to the present application and a plurality of optical sound cells exhibiting different acoustic characteristics and having the same reversible fixing element, wherein each of the plurality of optical sound cells is configured to be replaceable within the optical sound detection device.

[0036] Because the photoacoustic detection device is disassembled, a kit of different photoacoustic cells can be provided, allowing the user to swap out one cell for another when required. Advantageously, the cells exhibit different acoustic properties, so that different cells can be used to measure different parameters or signals.

[0037] According to one embodiment, the optical sound detection device kit further comprises a plurality of transducers of different types and / or exhibiting different characteristics, each transducer of the kit of transducers being attached to a holding element having the same size and characteristics as the second holding element, and all transducers of the kit of transducers being configured to be interchangeable within the optical sound detection device.

[0038] Thus, the user can also change transducers if, for example, a different signal needs to be measured.

[0039] Embodiments of the present invention are described below with reference to the drawings. [Brief explanation of the drawings]

[0040] [Figure 1] The photoacoustic detection device is attached to the arm of a person P. [Figure 2] FIG. 1 is a block diagram of a photoacoustic detection device. [Figure 3] 1 is a schematic diagram of the interior of an optical sound detection device according to an embodiment. [Figure 4] FIG. 2 is another schematic diagram of the interior of the optical sound detection device. [Figure 5] FIG. 10 is a top view of the second retaining element. DETAILED DESCRIPTION OF THE INVENTION

[0041] In the drawings, the same reference numbers indicate the same or similar objects.

[0042] The invention relates to an optical sound detection device 1 for measuring a parameter of interest in a medium M.

[0043] In a non-limiting example, the photoacoustic detection device 1 (hereinafter referred to as "detection device 1") is intended to be worn by a person P. The medium M can be organic tissue, such as the skin, of the person P wearing the detection device 1.

[0044] The parameters of interest may be chemical constituents, such as molecules, present on the skin of person P. The parameters of interest may include glucose, cholesterol, triglycerides, urea, albumin, and / or alcohol. This list is not exhaustive and several other parameters of interest may be measured.

[0045] The measured parameters can then be analyzed to determine blood levels of glucose, cholesterol, etc.

[0046] 1, the detection device 1 can be worn on the arm or wrist of the person P. The detection device 1 can be fixed to the arm of the person P by means of a bracelet.

[0047] When worn, the detection device 1 can enable continuous monitoring of the person P by repeatedly measuring a parameter of interest of the person P.

[0048] FIG. 2 is a block diagram of the detection device 1.

[0049] The detection device 1 comprises at least one light source 2 configured to emit an optical signal, a transducer 3 for acquiring the signal coming from the medium M, and a signal processing module 4 for analyzing the signal detected by the transducer.

[0050] In one embodiment, the transducer 3 may be an acoustic transducer that detects an acoustic signal generated in response to illumination of the medium M with an optical signal.

[0051] The transducer 3 can be connected to a signal processing module 4 which is adapted to receive the signal coming from the transducer 3 . do.

[0052] In a non-limiting embodiment, the signal processing module 4 may include an analog-to-digital converter that converts the signal acquired by the converter 3 into a numeric signal.

[0053] In another embodiment, the converter 3 can send the numerical signal directly to the signal processing module 4 .

[0054] The signal processing module 4 may be implemented in a processor (not shown) that may or may not be remote from the detection device 1 .

[0055] The detection device 1 may comprise other components, for example an adaptation module 5 for adapting the illumination parameters of the light source 2 and a memory 6. These components will not be described further.

[0056] In one embodiment, the light source 2 emits a light signal at a selected wavelength towards the medium to be analyzed M. The selected wavelength may be selected depending on the parameter of interest to be measured.

[0057] More precisely, the wavelength can correspond to the absorption peak of the parameter of interest being measured. As an example, when detecting glucose, the wavelength can be 1034 cm, which corresponds to the absorption peak of glucose. -1 It can be said that:

[0058] The light source may be a laser, more particularly a quantum cascade laser (QCL). In an alternative embodiment, the light source 2 may be an electroluminescent diode (led).

[0059] In one embodiment, the detection device 1 can comprise a plurality of light sources 2. In this embodiment, each light source 2 can emit an optical signal at a different wavelength. In a variant, some light sources 2 emit optical signals at the same wavelength, while other light sources 2 emit optical signals at different wavelengths.

[0060] In the following description, the detection device 1 is described as having only one light source 2, but it should be understood that the same specifications apply to multiple light sources 2.

[0061] An optical signal emitted from a light source 2 propagates into and passes through medium M. This phenomenon is represented by the dotted arrows in Figure 2. The optical signal is absorbed by components of medium M at a depth z, which depends on the selected wavelength of the optical signal, the frequency of the optical signal, and the composition of medium M.

[0062] Absorption of the energy of the optical signal causes local heating of the medium M. A thermal signal therefore propagates within the medium M, in particular towards the surface of the medium M (a phenomenon indicated by the arrows in Figure 2). Furthermore, the thermal wave can create a pressure wave that propagates outside the medium M. Such a pressure wave can be detected by the acoustic transducer 3.

[0063] In one embodiment, the heat waves may be detected by a heat transducer such as a thermometer (not shown).

[0064] The detection device 1 may comprise an acoustic transducer 3 and / or a thermal transducer 3. Other types of transducers 3 may be used.

[0065] Although two transducers 3 are shown in the figure, one or more than two transducers 3 may be used.

[0066] In the following description, the detection device 1 will be described as comprising only one transducer 3. It will be understood that what is described for one transducer also applies to multiple transducers 3.

[0067] FIG. 3 shows a schematic representation of a detection device 1 according to one embodiment.

[0068] The detection device 1 may comprise a housing 7 formed by a cover 71 and a base plate 72. The housing 7 comprises an interior bounded by an inner surface 710 of the cover 71 and an inner surface 720 of the base plate 72.

[0069] The interior of the housing 7 contains the light source 2, which may be a QCL as described above.

[0070] Also provided is a guide element 8. The guide element 8 is configured to direct the light signal emitted by the light source 2 towards the medium M to be analysed.

[0071] In an embodiment in which the detection device 1 comprises multiple light sources 2, the guide element 8 may also be configured to collimate each light signal emitted from each light source 2 into a single light signal directed towards the medium M to be analyzed.

[0072] More specifically, the guide element 8 is configured to guide the optical signal emitted from the light source 2 through an optoacoustic cell 9 (hereinafter referred to as "cell 9") positioned between the medium M to be analyzed and the light source 2.

[0073] The cell 9 extends from the guide element 8 to a hollow contact surface 91 of the cell 9, from which the medium M can be accessed. The cell 9 comprises a cavity 92 and a transmission line 93. An optical signal emitted by the light source 92 propagates within the optoacoustic cell 9 by first entering the cavity and then passing through the hollow contact surface 91.

[0074] The hollow contact surface 91 may have a generally ring-shaped configuration. The hollow contact surface 91 may also have a circular shape, with the hollow located at the center of the circle, giving the hollow contact surface a generally circular shape. Other configurations are possible.

[0075] The hollow portion of hollow contact surface 91 may be closed by a window of transparent material such as silicon, allowing an optical signal to pass across it.

[0076] The hollow contact surface 91 is intended to be placed against the medium M to be analyzed, and more precisely can be placed in direct contact with the medium M to be analyzed.

[0077] As a result, as shown in FIG. 1, when the detection device 1 is worn by a person P, the hollow contact surface 91 is placed in direct contact with the person P's skin.

[0078] For this purpose, the base plate 72 is provided with an opening 721 through which the hollow contact surface 91 emerges. The hollow contact surface 91 of the cell 9 is thus arranged outside the interior of the housing 7 and can come into direct contact with the medium M to be analyzed.

[0079] In photoacoustic detection, a thermal wave is generated under the influence of absorption by a medium of a light beam emitted from a light source. Such absorption causes local heating of chemical components in the medium that absorb the light beam. The thermal wave propagates through the medium M before propagating out of the medium. After propagation, when the thermal wave exits the medium, a pressure wave is generated, which propagates into the cell 9, where it can be detected. The pressure wave, i.e., the acoustic wave, is caused by the photothermal effect.

[0080] The transducer 3 is arranged inside the housing 7 and is preferably connected to the cell 9 by a transmission line 93 with an outlet facing the transducer 3 so that the transducer 3 can detect and measure the generated pressure waves. More precisely, the generated pressure waves propagate from the hollow contact surface 91, then propagate within the transmission line 93 and finally reach the transducer 3 through the outlet of the transmission line 93.

[0081] In embodiments in which the detection device 1 comprises more than one transducer 3, the transmission line 93 may comprise as many outlets as there are transducers 3.

[0082] Since it may become necessary for some reason to replace one of the elements of the detection device 1, the detection device according to the present application is considered modular, i.e. an element can be changed or replaced without the need to replace the entire detection device 1. In particular, such elements are the photoacoustic cell 9 and / or the transducer 3. Such replacement may be necessary because an element may fail, because it needs to be cleaned, or because the parameter of interest may be analyzed according to different characteristics not allowed by the photoacoustic cell 9 and / or transducer being used.

[0083] To solve this technical problem, the detection device comprises a first holding element 100. The first holding element 100 can be a metal plate or a printed circuit board (PCB). The first holding element 100 is used to hold the light source 2 and the guide element 8 together, as well as electronic components that will not be described here.

[0084] In one embodiment, the first holding element 100 holds the light source 2 and the guide element 8 in a non-removable manner, i.e. the light source and the guide element cannot be removed or easily removed from the holding element.

[0085] For example, the light source 2 and the guide element 8 may be attached to the holding element by means of screw elements that are not accessible to the user and that are only accessible by completely disassembling the detection device 1.

[0086] The first holding element 100, the light source 2 and the guide element 8 therefore form one single building block which in normal use is cinematically regarded as a rigid body.

[0087] A single building block may comprise an analog-to-digital converter, a signal processing module, an adaptation module 5 and / or a memory 6 .

[0088] In the following description, the first retaining element is considered to be the first PCB 100, although other applications and embodiments are within the scope of this application.

[0089] The first PCB 100 also ensures electronic and / or electrical connections between the components of the building block, in other words, the first PCB ensures electronic, electrical, and mechanical connections between the components of the building block.

[0090] The mounting of the photoacoustic cell 9 within the detection device 1 can be seen in more detail in FIG.

[0091] As mentioned above, the cell 9 comprises a hollow contact surface 91 emerging from an opening 721 in the base plate 72 .

[0092] When viewed from the outside of the housing 7, the hollow contact surface 91 has a generally ring-like shape. When viewed from the side in Figures 3 or 4, the hollow contact surface 91 has a dome-like or conical shape. Such a shape helps to maintain constant contact between the medium to be analyzed and the hollow contact surface 91.

[0093] Other shapes may also be used and are within the scope of this application.

[0094] A fixing element 95 can be used to attach the photoacoustic cell 9 to other parts of the detection device 1. Such a fixing element can be used to removably attach the photoacoustic cell to the guide element 8. The fixing element 95 can be a screw element, the head of which is accessible from outside the housing 7. Alternatively, the fixing element can be a clip element.

[0095] Thus, if required, the photoacoustic cell 9 can be easily removed from the detection device 1 by unlocking the fastening elements 95, i.e. by unscrewing the screwing elements or unclipping the clipping elements, without having to disassemble the entire detection device 1. To allow such disassembly, the openings in the photoacoustic cell 9 and base plate 72 are sized accordingly.

[0096] The skirt 96 may be disposed over the hollow contact surface 91 without covering the hollow portion of the hollow contact surface 91. The skirt 96 may extend beyond the hollow contact surface 91 onto the outer surface of the base plate 72. The skirt 96 may be made of a flexible and / or slightly elastic material such as rubber or silicone.

[0097] The advantage of this embodiment is that the material used for the skirt and the bond between the skirt 96 and the cell 9 ensures that the cell 9 is environmentally tight, ie not only watertight but also dusttight.

[0098] Alternatively, to ensure airtightness, sealing elements 98 may be provided between the skirt 96 and the cells 9. For example, the sealing elements 98 may be overmolded onto the hollow contact surfaces of the cells 9 or onto the outer periphery of the skirt, or the sealing elements 98 may be inserted between the hollow contact surfaces of the cells 9 and the skirt 96 and glued onto the hollow contact surfaces of the cells 9 or onto the outer periphery of the skirt 96.

[0099] The skirt 96 can hide the heads of the screw fastening elements 95. Thus, to remove the photoacoustic cell 9 if necessary, any suitable product can be used that can separate the skirt 96 from the hollow contact surface 91. Such a product can be a solvent or an alcohol.

[0100] In another embodiment, the skirt 96 may be a clip-on skirt 96 that can be clipped onto a pin (not shown) provided on the hollow contact surface 91 of the cell 9. The skirt 96 may be made of a flexible, resilient material such as plastic or silicone. In this embodiment, the skirt 96 may first be unclipped from the cell 9 to access the screw-on element 95.

[0101] To ensure the environmental tightness of the cells 9, i.e., watertightness and / or dusttightness, a sealing element 98 for ensuring the tightness can be provided between the skirt 96 and the cells 9. For example, the sealing element 98 can be overmolded onto the hollow contact surface of the cells 9 or onto the outer periphery of the skirt, or the sealing element 98 can be inserted between the hollow contact surface of the cells 9 and the skirt 96 and glued onto the hollow contact surface of the cells 9 or onto the outer periphery of the skirt 96.

[0102] The use of the skirt 96 is optional, but the skirt can improve contact between the hollow contact surface 91 and the medium to be analyzed, improve the comfort of the user wearing the detection device 1, and improve retention between the photoacoustic cell 9 and the housing.

[0103] 3, it can be seen that the cell 9, including the hollow contact surface 91, the cavity 92, and the transmission line 93, is formed as a whole, i.e., as a single piece. The cell 9 can be made of one material, for example, silicone or resin, or of two or more materials, for example, silicone and resin.

[0104] By making the photoacoustic cell 9 an integrally molded product, the manufacturing cost can be reduced and the cell 9 can be easily and quickly assembled into the detection device 1.

[0105] To enable detection of the signal generated by the transducer 3, the detection device 1 is provided with a second holding element 110.

[0106] The second holding element 110 can be a metal plate or a printed circuit board (PCB). In the following description, the second holding element is considered to be a second PCB 110, although other applications or embodiments are within the scope of the present application.

[0107] As can be seen from FIG. 3, the second PCB 110 has a first surface facing the first PCB 100 and a second surface facing the base plate 72 .

[0108] In one embodiment, the transducer 3 is held by brazing to the second surface of the second PCB 110. In this embodiment, the transducer 3 is permanently attached to the second PCB 110.

[0109] Thus, when a user needs to remove the transducer 3 from the detection device 1, the transducer 3 and the second retaining element are removed while remaining attached together. Because the transducer 3 and second retaining element are removed through the opening in the base plate 72, the second retaining element 110 can be sized to fit through the opening 721 in the base plate. In the example seen in Figure 5, the retaining element 110 can have a general U-shape.

[0110] When the transducer 3 detects the generated signal, the information contained in the generated signal can be sent to a component responsible for analyzing the detected generated signal. This component can be an analog-to-numeric converter or a signal processing module 4. In a preferred embodiment, the first PCB 100 carries the analog-to-numeric converter or the signal processing module 4, or at least the means necessary to send the information detected by the transducer to said analog-to-numeric converter or said signal processing module 4. A bridge can therefore be implemented between the first PCB 100 and the transducer 3.

[0111] Regarding the need to have a modular sensing device 1 that allows the transducer 3 to be disconnected from the rest of the sensing device 1, a bridge can be created by a connecting element. The connecting element can take the form of a leaf spring connector 31. In the following description, the connecting element is considered to be a leaf spring connector, although other types of connectors that have the same functionality as a leaf spring connector can also be used.

[0112] Advantageously, the second PCB 110 comprises a connection portion 111. As can be seen in Figure 3, the leaf spring connector 31 can couple the connection portion 111 of the second PCB 110 to the first PCB 100 to which the leaf spring connector 31 is brazed.

[0113] In one embodiment, the leaf spring type connector 31 is brazed onto the first PCB 100 so that the leaf spring type connector 31 cannot be removed from inside the detection device 1 without disassembling the detection device 1.

[0114] Advantageously, the distance between the first PCB 110 and the second PCB 110 is such that the leaf spring connector 31 disposed therebetween is in a slightly compressed state.

[0115] Advantageously, the compressed state is obtained by attaching a fixing element of the cell 9 to the detection device, ie by screwing a screwing element 95 or by clipping a clip element.

[0116] Thus, the leaf spring connector 31 and the connecting portion 111 together enable electronic, mechanical, and / or electrical connection between the transducer 3 and other electronic equipment, and more preferably, they enable electronic, mechanical, and electrical connection between the transducer 3 and other electronic equipment.

[0117] Such a configuration allows for very simple manufacturing, as leaf springs are commonly used as components in the electronics field, and also reduces manufacturing costs. Furthermore, the elasticity of the leaf spring connector 31 in a compressed state ensures a permanent connection between the connecting portions 111 of the first and second printed circuit boards 100, 110 when the detection device 1 is in use. Finally, the use of the leaf spring connector 31 provides a mechanical, electronic, and / or electrical connection without any fixing elements.

[0118] In one embodiment, each PCB may include multiple connection portions 111 and may use multiple leaf spring connectors 31 .

[0119] Furthermore, the second PCB 110 can be used to enable a mechanical connection between the cell 9 and the transducer. In one embodiment, the cell 9 can have an extension 97 that surrounds the transducer 3 and contacts the second surface of the second PCB 110. To achieve the mechanical connection between the cell 9 and the second PCB 110, an adhesive can be applied between the cell extension 97 and the second surface of the second PCB 110. Such an adhesive can be a non-permanent adhesive so that the cell 9 can be detached from the second PCB 110 as needed. By way of example, such an adhesive can be a double-sided tape.

[0120] According to the above-described embodiment, if access to the photoacoustic cell 9 and / or the transducer 3 is required, the user simply removes the photoacoustic cell 9 from the detection device and replaces it with another one. To do so, the user first removes the skirt 96 from the base plate 72 using a solvent or unclips the skirt 96, if appropriate. Next, the user unscrews the screw fastening elements 95 and removes the photoacoustic cell 9 from the housing interior through the opening 721 in the base plate 72. Advantageously, due to the type of adhesive used to hold the cell 9 to the second PCB 110, gently pulling the photoacoustic cell 9 through the opening will cause the extension 97 of the cell 9 to separate from the second PCB 110.

[0121] If the transducer 3 needs to be replaced, a similar operation is performed on the photoacoustic cell 9, and then the transducer 3 and second PCB 110 brazed to the second PCB 110 can be removed from the housing 7 through the opening 721 in the base plate 72.

[0122] To replace the transducer 3 and the photoacoustic cell 9, a user can insert a new or the same transducer into the detection device 1 through the opening 721 in the base plate. Advantageously, when installing a new transducer 3, the transducer 3 is already brazed onto the PCB corresponding to the second PCB 110. The second PCB 110 with the transducer 3 brazed thereto is inserted so that the connecting portion of the second PCB 110 faces the leaf spring connector 31.

[0123] Next, the photoacoustic cell 9 or a new photoacoustic cell is installed inside the detection device 1 through the opening 721 .

[0124] To facilitate the installation of the photoacoustic cell 9 inside the detection device 1, the extension 97 of the cell 9 may be provided with a stud 99, which cooperates with a corresponding hole 112 on the second PCB 110. This can be seen in FIG. 5 . Thus, the user can know that the photoacoustic cell 9 is in place. Furthermore, the stud 99 and the hole 112 may be used to align the transducer 3 and the transmission line 94 of the cell 9, and provide airtightness between the transmission line 94 of the cell 9 and the transducer 3. In other words, the stud 99 and the hole 112 help to avoid any leakage in signal detection due to poor airtightness or misalignment between the cell 9 and the transducer 3.

[0125] In another embodiment, the adhesive used to hold the cell 9 to the second PCB 110 does not allow the cell 9 to be separated from the second PCB 110 by simply pulling the cell 9 out of the housing 7. Thus, when the cell 9 is removed from the housing 7, the transducer 3 and the second PCB 110 move out of the housing along with the cell 9.

[0126] In one embodiment, once outside the housing 7, a user can remove the cell 9 from the second PCB 110 by pulling on the cell 9. The transducer and / or photoacoustic cell 9, or a new transducer 3 and / or a new photoacoustic cell 9, can then be replaced as described above.

[0127] In another embodiment, due to the type of adhesive used, the cell 9 cannot be separated from the second PCB 110. Thus, after removing the assembly formed by the transducer, second PCB, and cell, the user can replace the same assembly or a new assembly with the transducer brazed onto the second PCB and the photoacoustic cell glued to the second PCB.

[0128] In all the above-described embodiments, after replacing the elements inside the detection device, the user can screw in the screw-fastening element 95 and, if applicable, place the skirt 96 over the hollow contact surface of the cell 9.

[0129] As mentioned above, there may be a need to use photoacoustic cells 9 and / or transducers with different characteristics to analyze different parameters of interest.

[0130] For this purpose, the detection device 1 may comprise a kit of different photoacoustic cells 9 and / or different transducers 3 .

[0131] Advantageously, the converter 3 of the kit is already brazed to the PCB.

[0132] Advantageously, the kit comprises a plurality of assemblies including a photoacoustic cell bonded to a PCB and a transducer brazed to the PCB, each assembly may include different properties allowing for different analysis and detection of parameters of interest.

[0133] The transducers included in the kit can be of different types, e.g., thermal, acoustic, etc. Also, the photoacoustic cells 9 included in the kit can have different features. In a non-limiting embodiment, some cells 9 of the kit can have a hollow contact surface 91 or a window recovering the hollow contact surface 91. Other features are possible.

[0134] While exemplary embodiments of the present invention are described with reference to two primary embodiments, those skilled in the art will recognize that various modifications, omissions, and / or additions can be made, and equivalents can be substituted for elements, without departing from the spirit and scope of the invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is not intended that the invention be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but the invention is intended to include all embodiments falling within the scope of the appended claims. Furthermore, unless otherwise specified, the use of terms such as first, second, etc. does not denote any order or importance; rather, terms such as first, second, etc. are used to distinguish one element from another. [Explanation of symbols]

[0135] 1 Photoacoustic detection device 2 light source 3 Converter 7. Housing 8 Guide Elements 9 Photoacoustic Cell 71 Cover 72 base plate 91 Hollow contact surface 95 Fixed Elements 100 first holding element 721 Opening

Claims

1. An optical acoustic detection device (1) for measuring a parameter of interest in a medium, comprising: a housing (7) comprising a base plate (72) and a cover (71); a light source (2) configured to emit an optical signal; an optoacoustic cell (9) including a hollow contact surface (91) emerging from an opening (721) in the base plate (72), the hollow contact surface (91) being adapted to contact the medium, such that the optical signal can propagate within the optoacoustic cell (9) and pass through the hollow contact surface (91) to reach the medium; a guide element (8) configured to guide the optical signal to the photoacoustic cell (9); a transducer (3) coupled to a photoacoustic cell (9) and configured to detect an generated signal, the generated signal being generated in the photoacoustic cell (9) by a photothermal effect in the medium in response to illumination of the medium with the optical signal; a first holding element (100) configured to assemble the light source (2) and the guide element (8) into a construction block, the construction block being accommodated in the housing (7); and Equipped with the photoacoustic cell (9) is reversibly attached to the construction block by at least one fixing element (95) accessible from outside the housing (7), and the size of the photoacoustic cell (9) is such that it can be removed from the housing (7) as needed by passing through the opening (721) in the base plate (72); The photoacoustic detection device (1) is configured such that the transducer (3) is reversibly coupled to the building block and positioned between the building block and the photoacoustic cell (9), such that the transducer (3) can be removed from the opening (721) in the base plate (72) simultaneously with or after the photoacoustic cell (9) is removed from the housing (7).

2. 2. The optical sound detection device (1) of claim 1, wherein the transducer (3) is attached to a second holding element (110), the second holding element (110) having a connection portion (111) relative to the first holding element (100), the connection element being configured to reversibly connect the connection portion (111) of the second holding element (110) to the first holding element, thereby ensuring a mechanical, electronic and / or electrical connection between the transducer (3) and the building block.

3. 3. The optical sound detection device (1) according to claim 2, wherein removing the transducer (3) outside the housing (7) comprises removing the transducer (3) and the second holding element (110).

4. 4. Optical sound detection device (1) according to claim 2 or 3, wherein the connecting element is brazed onto the first holding element (100).

5. The optical sound detection device (1) according to any of claims 2 to 4, wherein the connecting element is a leaf spring type connector (31).

6. The optical sound detection device (1) according to any one of claims 2 to 5, wherein the fixing of the optical sound cell (9) to the optical sound detection device (1) by the fixing element (95) is such that the second holding element (110) is pressed against the connecting element.

7. 7. An optical sound detection device (1) according to any one of claims 2 to 6, wherein the optical sound cell (9) comprises an extension (97) reversibly attached to the second holding element (110), the extension (97) surrounding the transducer (3).

8. 8. The optical sound detection device (1) of claim 7, wherein the extension (97) of the optical sound cell (9) comprises a stud (97) configured to cooperate with a hole (112) provided in the second holding element (110).

9. 7. An optical sound detection device (1) according to any one of claims 2 to 6, wherein the optical sound cell (9) comprises an extension (97) permanently attached to the second holding element (110), the extension surrounding the transducer (3).

10. Photoacoustic detection device (1) according to claims 2 to 9, wherein the photoacoustic cell (9) is attached to the second holding element (110) by means of an adhesive, such as double-sided tape.

11. 11. An optical sound detection device (1) according to any one of claims 1 to 10, wherein the fixing element (95) for reversibly attaching the optical sound cell (9) to the construction block is a screw-fastening element, the head of which is accessible from outside the housing (7).

12. 12. An optical sound detection device (1) according to any one of claims 1 to 11, further comprising a skirt (96) provided on the surface of the hollow contact surface (91) of the optical sound cell (9), the skirt (96) being reversibly attached to the detection device (1).

13. A photoacoustic detection device (1) according to any one of claims 1 to 12; a plurality of photoacoustic cells (9) exhibiting different acoustic properties and having the same reversible fixation element (95); A photoacoustic detection device kit comprising: The photoacoustic detection device kit comprises a photoacoustic cell (9) of the plurality of photoacoustic cells (9), each of which is configured to be replaceable within the photoacoustic detection device (1).

14. 14. The optical sound detection device kit of claim 13, further comprising a plurality of transducers (3) of different types and / or exhibiting different characteristics, each transducer (3) of the kit of transducers (3) being attached to a holding element having the same size and characteristics as the second holding element (110), whereby each transducer (3) of the plurality of transducers (3) is configured to be interchangeable within the optical sound detection device (1).

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