Arrangement for preparing a sensor for a body monitoring device

Description

FIELD OF THE INVENTION

[0001] The invention relates to wearable devices used in body monitoring systems, for example for recording and monitoring biochemical parameters of the human body.

[0002] The invention relates in particular to an assembly for preparing a sensor comprising a capsule of a device for monitoring a body analyte, the capsule comprising a needle sensor(s) configured to provide a measurement of the concentration of body analyte, and a patch on which the sensor is mounted, the assembly making it possible to prepare and optionally protect the sensor. STATE OF THE ART

[0003] Monitoring many known chronic diseases in humans requires daily monitoring of biochemical parameters. A concentration level of a bodily analyte in a body fluid, such as blood plasma or the interstitial fluid of body cells, can be recorded.

[0004] As a common example, monitoring a patient's diabetes requires accurate daily recording of the patient's blood sugar levels.

[0005] One solution for monitoring diabetes is to perform a puncture, for example at the tip of the finger, to collect a drop of blood, then to take a daily measurement of blood sugar in the drop of blood thus obtained.

[0006] Monitoring systems have been proposed to eliminate the need for manual puncture, making blood glucose measurement less laborious and less invasive. These are called CGM systems, or Continuous Glucose Monitoring.

[0007] Some of these CGM systems measure blood glucose levels in the interstitial fluid between skin cells at regular intervals. Interstitial fluid glucose levels are very similar to blood plasma glucose levels. Interstitial fluid measurements allow for simple, minimally invasive monitoring of patient blood glucose levels; these measurements can be performed using needle sensors, transcutaneously, or non-invasively, such as iontophoresis or implantable with chemofluorescence measurement.

[0008] The international application published under number WO 2018 / 104647 describes a body monitoring system, usable in particular for monitoring blood glucose levels. This monitoring system includes an electronic watch that can be attached to the wrist using a bracelet. The watch has a case, into which is inserted an interchangeable removable capsule containing a micro-needle sensor. The sensor is automatically controlled by the electronics of the case, to perform a transcutaneous measurement. The blood glucose measurement by the sensor is an electrochemical measurement.

[0009] The body monitoring system described in the aforementioned document has the significant advantage of providing a self-contained calibration measurement by measuring a reference concentration of a body analyte in the user.

[0010] The number of manipulations that the user must perform to obtain daily measurements is greatly reduced. In particular, the user needs to perform few manual punctures (for example, a simple weekly puncture), or even no manual punctures at all. Another advantage of this system is its low hygiene risk, because the sensor needles are not in contact with the external environment once these needles are inserted into the skin.

[0011] Furthermore, maintenance of the aforementioned system is simple, as replacing a faulty sensor is as simple as removing the removable capsule and inserting a new one.

[0012] However, a significant amount of time – for example, several months – may elapse between the production of the removable capsule containing the microneedle sensor and the insertion of the removable capsule into a wearable device worn by the user. In addition, the quality of the blood glucose measurement provided by the sensor deteriorates during such a long period of non-use of the sensor between production and use.

[0013] The deterioration in the measurement performance of the needle sensor is explained by a drift in the electrochemical measurement over time. This drift may be due to an unsuitable ambient temperature in the storage areas of the removable capsules containing the needle sensors. In particular, excessively high temperatures are detrimental to the integrity of the measurement system.

[0014] If sudden and significant variations in the sensor temperature occur, this aggravates the drift of the electrochemical measurement.

[0015] A first known method to overcome this drift is a "factory" calibration carried out on the scale of an entire batch of needle sensors, at the end of the production of the batch. An alphanumeric code is then written on a packaging of the removable capsule containing the sensor, or is integrated into an electronic memory of the sensor. The ready-to-wear device has a chart in which each alphanumeric code is associated with a reference value. When the capsule is inserted into the ready-to-wear device, the alphanumeric code is read and the calibration can be carried out.

[0016] This known state-of-the-art factory calibration, based on the use of charts, is not, however, entirely satisfactory. Drifts in the electrochemical measurement provided by the sensor are still observed.

[0017] A second known calibration method, sometimes used in combination with the first, consists of calibration measurements (manual punctures) performed regularly by the user while wearing the wearable device. The calibration measurements are performed manually by the user, for example daily or weekly. To perform the manual calibration, the user may be required to enter a capillary blood glucose value on the wearable device.

[0018] In this second method, which can be combined with the first, the user is responsible for the proper calibration of their own ready-to-wear device. Regular manual operation is required, which goes against one of the objectives of an autonomous body monitoring system, namely to limit the discomfort felt by the user.

[0019] In view of the above considerations, the state of the art is not satisfactory regarding the preparation of needle sensors for ready-to-wear devices, such as needle-based electronic watches or needle-based patches. Some known systems do not ensure lasting accuracy of the electrochemical measurement, and other known systems require regular calibrations which must be implemented by the user. STATEMENT OF THE INVENTION

[0020] An objective of the invention is to propose improvements for a body monitoring device comprising a needle sensor(s), so that the measurement provided by this sensor remains reliable and precise over time.

[0021] In particular, we are looking for a solution to easily calibrate this sensor, while limiting the inconvenience caused to the user. The objective is to eliminate the need for daily manual punctures and to move to minimums to weekly manual punctures, or even to eliminate the need for manual punctures.

[0022] As a corollary, it is desired that the user of the body monitoring device is not responsible for the proper calibration of said sensor during the life cycle of the monitoring system. It is desired to avoid the need to regularly puncture the finger to perform daily calibration of the sensor.

[0023] The desired solution must remain very simple to use, in order to ensure a pleasant user experience.

[0024] Furthermore, all of this must be able to be done under conditions such that the sensor remains protected until its final destination.

[0025] In this respect, the invention relates to an assembly comprising a capsule of a device for monitoring a body analyte, the capsule comprising a sensor configured to provide a measurement of body analyte concentration, the sensor comprising a sensor surface and at least one needle attached to the sensor on the sensor surface, the capsule further comprising a patch supporting the sensor, the patch at least partially covering the sensor surface, a portion of the patch defining an opening in which the needles of the sensor are arranged, the assembly being characterized in that it comprises: at least one first compressible spacer, having a first face facing the patch and a second face opposite the first face, a pierceable pocket arranged at a distance and facing the needle, the assembly being such that when the needle is pushed towards the pocket it pierces the pocket, the spacer being compressed,the needle returning opposite and away from the pocket in the absence of any push, the spacer being decompressed.,

[0026] The invention is advantageously supplemented by the following characteristics, taken alone or in any of their technically possible combinations.

[0027] The assembly comprises a rigid membrane attached to the second face of the spacer and extending away from and opposite the needle, said membrane being configured to close the opening in order to protect the needle.

[0028] The rigid membrane is formed from an elastic or semi-elastic material.

[0029] The membrane can be pierced by the needle, the pocket being arranged below the membrane, the assembly being configured so that when the needle is subjected to a thrust in the direction of the membrane it pierces, in addition to the pocket, the membrane and returns completely into the opening opposite and at a distance from the membrane in the absence of a thrust.

[0030] The pocket is arranged in the opening and rests on a surface of the membrane which opens into the opening.

[0031] The spacer in the compressed or uncompressed position has a thickness greater than or equal to 0.1 millimeters and less than or equal to 2 millimeters.

[0032] The spacer comprises at least a first spacer portion and a second spacer portion opposite the first portion, the first portion and the second portion preferably being disjointed.

[0033] The patch includes a peelable film between the adhesive layer of the patch and the spacer, the first side of the spacer being fixedly adhered to the peelable film, the peelable film being configured to allow the peelable film, the spacer, and optionally the membrane to be peeled from an outer layer of the patch.

[0034] The assembly comprises a receptacle, the sensor being movable relative to the receptacle between a first position in which the needle is at a distance from and in front of the pocket, the spacer then being uncompressed, and a second position in which the pocket is pierced by the needle and in which the needle is in contact with a volume of the pocket, the spacer then being compressed.

[0035] The assembly includes at least a first bearing element located opposite the spacer, the first bearing element being configured to facilitate compression of the spacer and piercing of the pocket by the needle.

[0036] The assembly includes at least a second support element located opposite the pocket, the second support element being configured to facilitate piercing of the pocket.

[0037] The volume of the preparation bag includes a calibration solution having a glucose concentration equal to a reference value greater than or equal to two millimoles of glucose per liter and less than or equal to 20 millimoles of glucose per liter.

[0038] The preparation bag volume includes a wetting solution configured to wet active elements of the needle.

[0039] The assembly comprises support means mounted on the receptacle, the support means being configured to move the sensor relative to the receptacle from the first position to the second position, the support element then acting as a counter-support.

[0040] The set allows you to pre-wet the needles and calibrate the sensor.

[0041] The membrane protects the needles in a sterile environment as long as it is not pierced before use. This protects the needles from possible impacts, dust, etc. that may occur during handling of the capsule once the needles are wet.

[0042] Furthermore, once the sensor is calibrated, its commissioning is simple thanks to the presence of the peelable film which releases the needles for insertion into the user's skin. PRESENTATION OF THE FIGURES

[0043] Other characteristics, aims and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which: there Figure 1 illustrates an overview of a device for monitoring a body analyte Figure 2 illustrates a schematic view of a needle sensor according to the invention; the Figure 3a and the Figure 3b illustrate an assembly for preparing a sensor according to a first embodiment of the invention in a first position and in a second position; the Figure 4a and the Figure 4b illustrate an assembly for preparing a sensor according to a second embodiment of the invention in a first position and in a second position.

[0044] Throughout the figures, similar elements have identical references. DETAILED DESCRIPTION

[0045] The following description relates to the preparation of a needle sensor integrated into an electronic watch. The sensor is designed to provide a measurement of glucose concentration in the interstitial fluid of a wearer. The electronic watch, together with the sensor, constitutes a body monitoring device.

[0046] By "body monitoring" is meant the verification of biochemical constants of the wearer of the monitoring system, typically the concentration of the wearer's interstitial fluid in a protein, a hormone, a biomarker, in oxygen, in nutrients, etc. Those skilled in the art will readily understand that other physical quantities can be monitored by the monitoring system, such as for example the concentration of lactate, hydration, etc.

[0047] Throughout the following, the biochemical constant to be monitored is, for example, the glucose (or blood sugar) concentration in the interstitial fluid of the skin. The blood sugar in the interstitial fluid is considered representative of the blood sugar in the blood plasma. It will be understood that the sensor preparation kit described below can be used, with the same advantages, to prepare a sensor intended to measure another biochemical parameter. In addition, the sensor needle or needles could be intended to be inserted into a body fluid other than the interstitial fluid, for example into the blood.

[0048] Furthermore, the wearable device is, throughout the description below, an electronic watch configured to display information to its wearer. However, the sensor preparation assembly described below can be used, with the same advantages, in association with any other type of wearable device: bracelet, tracker, electronic patch, electronic radio reader, etc. General architecture of a body monitoring device

[0049] There Figure 1 illustrates a body monitoring device 1 comprising a housing 2, a sensor 3 and an adhesive patch 4.

[0050] The sensor 3 is in this case a needle sensor intended to provide a measurement of electric current within the interstitial liquid of the wearer of the device 1.

[0051] Needles 5 are advantageously arranged on an internal face 31 of the sensor 3. This internal face 31 is intended to be placed on the wearer's skin.

[0052] The sensor 3 is assembled to the adhesive patch 4 together constituting a capsule. The sensor 3 can also be removable with respect to the patch 4. Such a capsule is advantageously mounted removably with the housing 2. In particular, the capsule and therefore the sensor 3 preferably engages in a cavity 21 of the housing 2 located on its face intended to be in contact with the skin. The sensor 3 comprises an external face 32 opposite the internal face 31.

[0053] The housing 2 and the capsule may have complementary shapes, which limits the effort required for the correct insertion of the capsule against the housing 2.

[0054] The patch 4 comprises an adhesive layer, or is itself formed from an adhesive material. The patch therefore allows the capsule to be attached to the wearer's skin, and helps keep the needles 5 in the interstitial fluid. The patch 4 has, for example, an annular shape, and covers the capsule.

[0055] The sensor 3 illustrated here is circular in shape with a central orifice 33 but it can take other shapes: rectangular, oblong, ellipsoidal with or without a central orifice. The central orifice 33 makes it possible to correctly position the sensor 3 in the cavity 21 of the housing which includes a central positioning stud (not shown).

[0056] The sensor 3 therefore includes elements which make it possible to collect the liquid or to bring the signals detected by each microneedle to the box 2 for processing (not described here).

[0057] The sensor 3 can take the form of a plastic plate, a printed circuit (rigid or flexible silicon), or a non-conductive metal plate such as aluminum.

[0058] The adhesive patch 4 is adapted to be stuck to the skin and supports the sensor 3 and allows the housing 2 to be detached without removing the sensor 3 while keeping it stuck to the body. Such a configuration makes it possible to avoid removing the sensor for certain operations which only involve the housing: recharging the battery, repair, replacement, extracting data to a computer.

[0059] The case 2 is advantageously in the form of a watch case and comprises means 23 for attaching the device to a user's wrist. This is in particular a bracelet adapted to surround a user's wrist. The bracelet is preferably adjustable.

[0060] The housing 2 houses several elements for analyzing or extracting interstitial fluid. In this respect, reference may be made to document WO 2019 / 141743 in the name of the applicant, which describes in detail the measurement and detection of a physical quantity using microneedles in contact with a bodily fluid that may or may not be sampled.

[0061] Advantageously, the watch further comprises a wireless communication interface, for example via a 3G and / or 4G and / or 5G and / or Wi-Fi and / or Bluetooth and / or NFC and / or DECT type telecommunications network.

[0062] Also, the watch may include a light indicator such as a diode, which may be used to signal the end of a sensor preparation operation.

[0063] The needles 5 are advantageously micro-needles. The sensor 3 preferably comprises between four and fifty micro-needles or even four hundred micro-needles. Of course, a different number can be considered without this limiting the description of the invention given here.

[0064] A microneedle is understood to mean a needle having a low height, preferably between 10 µm and 1000 µm, preferably between 0.3 mm and 0.8 mm. The height of the microneedles is low enough to avoid contact with a mechanical pain nerve of the wearer when the device is worn.

[0065] Microneedles 5 are used to measure or collect body fluid.

[0066] The microneedles 5 are hollow when it comes to sampling liquid or full to analyze the liquid directly. When it comes to sampling the liquid, the microneedles allow the extraction of interstitial liquid from the dermis in a painless manner without blood beading and send it to a sensor housed in the housing 2. When it comes to analyzing liquid, the microneedles do not sample liquid and integrate the sensor on their surface in the form of a coating such as a biochemical material capable of reacting with the analysis to be carried out on the liquid.

[0067] The length of the needles 5 is thus sufficiently reduced to avoid contact with a nerve of the user, to limit the pain caused by wearing the device 1.

[0068] Each needle has a pyramidal shape, for example.

[0069] In the present example, each needle 5 comprises on its surface at least one chemical or biochemical material capable of reacting with the bodily analyte of which a measurement is desired (i.e. here glucose). A material capable of reacting with the bodily analyte is for example an enzyme capable of oxidizing the bodily analyte.

[0070] In an alternative example, each needle 5 includes an internal cavity located at the rear of the tip, and the chemical or biochemical material capable of reacting with the analyte is located in this internal cavity.

[0071] In another alternative example, the sensor 3 may comprise cavities located behind the needles 5, and / or inside the needles 5. For example, one or more needles 5 may comprise an open channel. The cavities comprise the chemical or biochemical material capable of reacting with the analyte. The needles 5 are then capable of bringing the body fluid up to said cavities.

[0072] Advantageously, the sensor 3 comprises several microneedles which consist of a network of microneedles in that they are electrically connected to each other in groups. The microneedles pierce the skin to come into contact with the interstitial fluid when the sensor is in contact with the skin.

[0073] Sensor 3 shown on the Figure 2 comprises, in addition to the needles 5, a substrate 311 provided with a plurality of metal tracks 312, a working conductivity electrode 313, a reference conductivity electrode 314.

[0074] When using the sensor 3 to perform a measurement, a voltage is generated between several needles. At least a portion of the needles 5 of the sensor 3 are at least partially immersed in the interstitial fluid. The chemical or biochemical material present on the surface of the needles 5 reacts with the glucose in the interstitial fluid.

[0075] Sensor 3 thus provides an electrical current measurement, representative of the glucose concentration in the interstitial fluid.

[0076] The substrate 311 and the needles 5 are preferably arranged on a single face of the sensor 3, which is the face facing upwards according to the orientation of the Figure 2 This upper face is intended to be placed facing the user's skin.

[0077] Each needle extends from the top face in a Z direction, from its base to its tip. The Z direction is preferably orthogonal to a plane of the top face.

[0078] The central opening 33 is here circular in shape. The sensor 3 thus has, in this example, a generally annular shape.

[0079] For a detailed example of the structure of sensor 3, reference may be made to the international application published under number WO 2020 / 025822 and in particular to the description relating to the Figures 1 And 2 of this document.

[0080] A support for the sensor 3 (e.g., the removable capsule) preferably comprises a patch (not shown) attachable to the user's skin.

[0081] The sensor 3 is here intended to be controlled by the processing unit 14 of the watch 10.

[0082] In a possible variant, the sensor 3 comprises a memory, configured among other things to record recalibration information. The recalibration information can then be recorded in the sensor 3 after transmission by a processing unit integrated into the watch 10, during a calibration process of the sensor 30. Set: capsule and pocket

[0083] The following describes an assembly comprising a capsule and a pocket for “preparing” the sensor before its use and in particular its installation in the housing 2.

[0084] THE Figures 3a , 3billustrate an assembly comprising a capsule 10 and a pocket 40 according to a first embodiment presented according to a first position and a second position. The Figures 4a , 4b illustrate an assembly comprising a capsule 10 and a pocket 40 according to a second embodiment presented according to a first position and a second position.

[0085] In particular, and as already indicated, the capsule 10 comprises, in addition to the sensor 3, the patch 4 to which the sensor 3 is attached, the patch 4 covering at least in part the surface of the sensor 3. A part, for example a central part of the patch 4, defines an opening 12 in which the needles 5 of the sensor 3 are arranged. A surface of the sensor 5 is considered here to be the internal surface 31 of the sensor 5 which is directed towards the skin of the wearer. On the Figures 3a , 3b And 4a , 4b patch 4 is below sensor 3, however patch 4 can be above sensor 3.

[0086] The opening 12 preferably has, in a diametrical direction, a minimum dimension, greater than or equal to 2 millimeters, preferably greater than or equal to 5 millimeters. The opening 12 therefore defines a free space in which the needles 5 are arranged. The opening 12 in which the needles are positioned therefore advantageously constitutes a cavity which makes it possible to protect the needles 5 in particular if they are to be handled with a view to installing the sensor 3 in the housing 2.

[0087] The opening 12 is advantageously closed in its lower part by a rigid membrane 7a, 7b which can be pierced. We will come back to this. The lower part of the opening 12 is the one which is open. The membrane 7a, 7b makes it possible to close the open part of the opening 12 and therefore makes it possible to protect the needles 5 in the enclosure formed by the opening 12 and the membrane 7a, 7b.

[0088] A membrane is understood to mean a rigid layer of material(s) which has a thin thickness greater than or equal to 0.05 mm and less than or equal to 0.50 mm.

[0089] The rigid membrane 7a, 7b is formed from a layer of elastic or semi-elastic material. For example, the membrane is made from a mesh of fine threads, an average thickness of the mesh preferably being greater than or equal to 0.05 millimeters and less than or equal to 0.50 mm.

[0090] Alternatively, the membrane is made of rubber or artificial skin or metal or paper. Of course, other materials or combinations of materials are possible.

[0091] At least one compressible spacer 9 having a first face 91 and a second face 92 opposite the first face 91 is attached to the patch 4 at the level of the opening 12.

[0092] In addition, a pierceable pocket 40 is arranged at a distance from and opposite the needle(s) 5.

[0093] According to this configuration, when the needle(s) undergo a thrust towards the pocket 40 they can pierce the pocket 40 and conversely exit the pocket in the absence of the thrust F (see the Figures 3b And 4b on which pocket 40 is pierced).

[0094] In particular and in a complementary manner, the spacer 9 is configured to decompress once the thrust F is released, so that the needle 4 returns to a position at a distance from the pocket in the opening 12.

[0095] It is the compressible nature of the spacer 9 (which can be compressed) which therefore allows the needles to pierce the pocket 40.

[0096] The spacer 9 is therefore sized and configured in particular to come to bear on a first support element 212 opposite and to compress on this first support element 212. This first support element 212 plays the role of counter-support for the spacer 9.

[0097] Advantageously, the spacer 9 has an average thickness in the compressed or uncompressed position which is greater than or equal to 0.1 millimeters and is less than or equal to 2 millimeters.

[0098] Furthermore, the thickness of the spacer 9 is chosen according to the height of the needles 5 and the thickness of the patch 4.

[0099] Preferably, the spacer 9 is made of an elastic or semi-elastic material and is for example a foam having elastic properties. It can also be for example rubber or a spring blade.

[0100] Preferably, the spacer 9 comprises at least a first spacer part 9a and a second spacer part 9b, the spacer 9 being formed of several parts. In a complementary manner, the first part 9a and the second part 9b are disjointed. Alternatively, the first part and the second part are in one piece. On the other hand, when the spacer is made up of disjointed parts, these may be 3, 4 or even more in number. In all cases, the spacer surrounds the needles 5 at the level of the opening 12 as is visible on the Figures 3a , 3b , 4a , 4b .

[0101] The thrust F required to pierce the pocket 40 is greater than or equal to 10 Newtons and less than or equal to 50 Newtons, preferably equal to 10 Newtons. Knowing that 10 Newtons corresponds to 1 kg of support, this corresponds to what an elderly person or a child can easily do. In other words, this covers a large number of users. The pocket 40 and spacer 9 assembly are therefore configured in this way.

[0102] The patch 5 comprises different layers of adhesive 8 for fixing the sensor 3 to the outer layer 41 of the patch 4. Layers of adhesive also make it possible to fix the spacer 9 to a peelable film 11 and to fix the membrane 7a, 7b to the spacer 9 on its other face 92. The idea here is to be able to simply detach by removing the peelable film 11 from the outer layer 41 of the patch 4, the one that will remain after the installation of the sensor 3, the spacer 9 and the membrane 7a, 7b. It is specified that peelable material is understood to mean a surface coating that can be detached dry and without breaking.

[0103] A receptacle 21 houses the above elements and comprises in particular a receiving surface 210 on which the support element 212 is arranged opposite the spacer 9 in order to facilitate its compression. Such a support element 212 takes the form of a boss projecting from the receiving surface 210 of the receptacle 21, the boss 212 being placed opposite the spacer 9. In the case where there are several spacers, as many bosses as there are spacers are provided.

[0104] The receiving surface 210 is in the lower part 21a of the receptacle 21.

[0105] An upper part 21b of the receptacle forms a cover and is removed to be able to position the capsule in the housing 2.

[0106] The receptacle 21 comprises all the elements described above and constitutes a sterile storage enclosure for the capsule in order to prepare the sensor 3.

[0107] Thus, the receptacle 21 is generally parallelepipedal in shape and takes the form of a box inside which the sensor 3, the patch 4 and the pocket 40 are placed. Alternatively, the receptacle 21 can be a charging dock, etc.

[0108] The membrane 7a, 7b therefore protects the needles of the sensor 3 against contamination and vibrations while the sensor 3 is on the patch 4, and allows in combination with the preparation bag to calibrate or pre-wet the needles when the sensor is pushed towards the bag.

[0109] In operation, the sensor 3 is movable relative to the receptacle 21 between a first position in which the needle 5 is at a distance from and facing the membrane 7a, 7b and the pocket 40, the spacer 9 then being uncompressed, and a second position in which the membrane 7a, 7b and the pocket 40 are pierced by the needle 5 and in which the needle 5 is in contact with a volume of the preparation pocket 40, the spacer 9 then being compressed.

[0110] In this respect, the assembly comprises support means mounted on the receptacle 21, the support means being configured to move the sensor 2 relative to the receptacle 21 from the first position to the second position, the boss 212 acting as a counter-support for the spacer 9. The support means are the cover 21b of the receptacle 21 or the housing 2, the sensor 3 then being assembled to the housing 2. Preparation bag

[0111] Bag 40 (or preparation bag) comprises a volume of a sensor preparation solution.

[0112] Here, the preparation solution is a calibration solution, having a volume concentration of a body analyte equal to a predetermined reference value.

[0113] It is recalled that, in the present example, the bodily analyte to be analyzed is glucose, and the measurement provided by sensor 3 is representative of blood sugar.

[0114] Thus, the solution contained in the bag 40 here has a precisely known glucose concentration. This concentration is advantageously between 2 millimoles of glucose per liter and 20 millimoles of glucose per liter, more preferably between 6 millimoles of glucose per liter and 10 millimoles of glucose per liter.

[0115] Alternatively, the preparation solution contained in the pocket 40 may be a pre-wetting solution, i.e. a solution that reproduces the chemical nature of the body fluid into which the sensor 3 is intended to be inserted (namely the interstitial fluid here). Pre-wetting consists of moistening a portion of the chemical or biochemical materials (such as active enzymatic elements) that enable the electrochemical measurement, contained for example on the upper layers of the needles 32. These chemical elements typically comprise active enzymatic elements. By virtue of pre-wetting, the subsequent passage of the electrical elements between all of the chemical layers and the human body fluid (for example in the interstitial fluid) is accelerated, once the needle sensor is in place.

[0116] An advantage of performing pre-wetting of the sensor 3, during a preparation of the sensor 3, is to accelerate the convergence of subsequent measurements of the sensor in the body fluid. The sensor 3 thus quickly reaches an operational state.

[0117] The preparation solution is produced here in the form of a gel.

[0118] Alternatively, the preparation solution can be a liquid solution.

[0119] It will be noted that the pocket 40 may contain a solution which serves both, among other possible uses, as a calibration solution and as a pre-wetting solution.

[0120] Regardless of the form chosen for the preparation solution contained in the pouch 40, the pouch preferably further comprises an envelope which surrounds the volume of preparation solution, to allow the transport and handling of the pouch 26.

[0121] The bag 40 is pierceable, so that a needle 5 of the sensor 3 can reach the preparation solution. If an envelope is present, this is at least partly pierceable. First embodiment: pocket on a receptacle

[0122] We return in detail to the Figures 3a And 3b which illustrate a preparation set according to a first embodiment.

[0123] According to this first embodiment, the pocket 40 rests on the receiving surface 210. This receiving surface 210 must be sufficiently rigid to hold the pocket 40. The pocket 40 is below the membrane 7a. In addition, this receiving surface 210 acts as a counter-support to allow the pocket 40 to be pierced.

[0124] Also, the assembly according to this first embodiment comprises the membrane 7a which, in addition to being rigid, is here piercable and is fixed on the second face 92 of the spacer 9 and extending at a distance from and opposite the needles 5.

[0125] The membrane 7a is piercable and the assembly is such that when the needles 5 undergo a thrust F in the direction of the membrane 7a they can pierce the membrane 7a. Conversely, when the needles 5 do not undergo a thrust, the needles return to the opening 12 above the membrane 7.

[0126] It is specified that rigid is understood to mean that the membrane can oppose a force of resistance to penetration by a needle, the membrane being able to be pierced when the thrust is greater than this force of resistance.

[0127] The membrane 7a is therefore such that it ensures that the needles return to the opening 12 above the membrane 7a when no thrust is applied to the needles 5.

[0128] Advantageously, the membrane 7a must be such that it does not catch on the needle 5 in the absence of thrust to allow the needles to return well above the membrane 7a.

[0129] Advantageously, to pierce the membrane 7a and the pocket 40 a thrust force necessary to pierce the membrane 7a is greater than or equal to 1 Newton and less than or equal to 50 Newton, preferably equal to 10 Newton. Here again, such a force can be deployed by a large number of users.

[0130] The membrane 7a is here attached to the spacer 9 by means of an adhesive layer 8 and can be removed when the peelable film 11 is detached from the outer layer 41 of the patch 4.

[0131] In use, a user has the set as illustrated in the Figure 3a and wants to install a sensor 3 in box 2, the assembly being “new”.

[0132] The user takes hold of the assembly and opens the upper part 21b of the receptacle. The capsule 10 is still in the receptacle 21 and the user brings the box 2 to connect it to the sensor 3 via its external face 32.

[0133] Then, a thrust F is exerted on the sensor 3 via the housing 2. This has the effect that the needles pierce the membrane 7 and the pocket 40 as can be seen in the Figure 3b, the membrane 7 deforming during the operation and the spacer 9 compresses onto the elements 212. The pre-calibration necessary at the start of the user cycle of the sensor 3 is therefore carried out, the sensor 3 being powered via the housing 2 (not described in detail). As such, the pre-calibration corrects a possible drift in the measurement of the electric current provided by the needles 5 of the sensor 3. The needles 5 are immersed in a volume of a calibration solution contained in the pocket 40. The concentration of bodily analyte (here glucose) in the calibration solution being known, the value of the expected electric current measurement is also known. A correction of the electric current measurement or correction of the delivered voltage is then carried out as a function of the value of the expected electric current measurement.

[0134] It should be noted that the preparation of the sensor 3 does not necessarily include a calibration of a measurement provided by the sensor 3. The preparation of the sensor 3 may only include a wetting of the needle(s), in particular a pre-wetting to accelerate the subsequent convergence of the measurement provided by the sensor 3.

[0135] The preparation of the sensor 3 can also include a combination of pre-wetting and pre-calibration, the entire invention being able to allow both.

[0136] Once the needles have been dipped into the pocket, the pushing force is released and the needles leave the pocket 40 and pass back through the membrane 7 to return to the opening 12. The assembly then returns to the position illustrated in the figure. Figure 3a .

[0137] The user takes hold of the capsule 10 which includes the sensor 3 and the patch 4 and also the membrane 7a. The capsule is therefore at this moment in the open air.

[0138] During this entire phase, the needles 5 are protected by the membrane 7a.

[0139] Then, the user positions the capsule 10 around his wrist and then removes the peelable film 11 which, during its removal, brings with it the membrane 7a, the spacer 9 and allows the user to adhere the patch 4 to his skin, the adhesive layer 8 directly in contact with the external layer 41 of the patch 4 being released. Second embodiment: pocket on membrane

[0140] We return in detail to the Figures 4a And 4b which illustrate an assembly according to a second embodiment.

[0141] The assembly according to this second embodiment includes all the elements of the first embodiment with the difference that the pocket 40 is here arranged on the membrane 7b. This membrane 7b is not intended to be pierced by the needles so that only the rigidity property is sought in order to support the pocket 40.

[0142] On the other hand, pocket 40 can be pierced by needles 5.

[0143] According to this second embodiment, at least one second support element 213 is arranged below the pocket 40. As illustrated, on the Figure 4a , these are two bosses 213 projecting from the receiving surface 210. These second support elements serve to facilitate the piercing of the pocket 40 by the needles since in operation, the membrane and the pocket will come to bear on these support elements, the spacer 9 bearing as on the first support elements 212 as described previously.

[0144] The operation of the assembly according to the second embodiment is similar to that of the first embodiment except that when the peelable film is removed, the pouch is also removed.

[0145] There Figure 4billustrates the assembly according to the second embodiment with the pocket 40 pierced by the needles 5, the membrane 7 is positioned on the support elements below, and the spacer 9 is compressed on the first support elements 212. In this way, the calibration of the needles 5 can be carried out as described previously, the assembly returning to the position of the Figure 4a at the end of the operation.

Claims

1. Assembly comprising a capsule (10) of a ready-to-wear device (1) for monitoring a body analyte, the capsule (10) comprising a sensor (3) configured to provide a measure of body analyte concentration, the sensor (3) comprising a sensor (3) surface (31) and at least one needle (5) attached to the sensor (3) on the sensor (3) surface (31), the capsule (10) further comprising a patch (4) supporting the sensor (3), the patch (4) covering at least part of the surface (31) of the sensor (3), part of the patch (4) defining an aperture (12) in which the needles (5) of the sensor (3) are arranged, the assembly being characterized in it comprises: - at least one first compressible spacer (9), with a first face (91) opposite the patch (4) and a second face (92) opposite the first face (91), - a receptacle (21) comprising a receiving surface (210); - a pierceable pouch (40) arranged on the receiving surface (210) at a distance from and opposite the needle (5), the assembly being such that when the needle (5) is being pushed (F) in the direction of the pouch (40), it pierces the pouch (40), the spacer (9) being compressed, the needle (5) coming back opposite and at a distance from the pouch (40) in the absence of the spacer (9) of any thrust (F), the spacer (9) being decompressed, the sensor (3) being movable relative to the receptacle (21) between a first position in which the needle (5) is at a distance from and facing the pouch (40), the spacer (9) then being uncompressed, and a second position in which the pouch (40) is pierced by the needle (5) and in which the needle (5) is in contact with a volume of the pouch (40), the spacer (9) being compressed, the pouch (40) comprising a volume of a sensor preparation solution (3).

2. The assembly according to claim 1, comprising a rigid membrane (7a, 7b) fixed to the second face (91) of the spacer and extending away from and opposite the needle (5), said membrane (7a, 7b) being configured to close the aperture (12) to protect the needle (5).

3. The assembly according to claim 2, wherein the rigid membrane (7a, 7b) is formed from an elastic or semi-elastic material.

4. The assembly according to any one of the preceding claims, wherein the membrane (7a) is pierceable by the needle (5), the pouch (40) being arranged below the membrane (7a), the assembly being configured so that when the needle (5) undergoes a thrust (F) in the direction of the membrane (7a), the needle (5) pierces the membrane (7a) in addition to the pouch (40) and returns completely to the aperture (12) opposite and at a distance from the membrane (7a) in the absence of a thrust (F).

5. The assembly according to any one of claims 1 to 3, wherein the pouch (40) is arranged in the aperture (12) and rests on a surface (7b1) of the membrane (7b) which opens into the aperture (12).

6. The assembly according to any one of claims 1 to 5, wherein the spacer (9) in compressed or uncompressed position has a greater thickness or equal to 0.1 millimeter and less than or equal to 2 millimeters.

7. The assembly according to any one of claims 1 to 6, wherein the spacer (9) comprises at least a first spacer part (9a) and a second spacer part (9b) opposite the first part (9a), the first part (9a) and the second spacer part (9b) being joined together, the second part (9a) being preferably disjoint.

8. The assembly according to any one of claims 1 to 7 or claims 2 to 7, wherein the patch (4) comprises a peelable film (11) between an adhesive layer (8) of the patch (4) and the spacer (9), the first face (91) of the spacer (9) being fixedly bonded to the peelable film (11), the peelable film (11) being configured to enable the peelable film (11), the spacer (9), and optionally the membrane to be detached from an outer layer (41) of the patch (4).

9. The assembly according to any one of claims 1 to 8, comprising at least a first support element (212) located opposite the spacer (9), the first support element being configured to facilitate compression of the spacer (9) and piercing of the pouch (40) by the needle (5).

10. The assembly according to any one of claims 1 to 8, comprising at least one second support element (210, 213) located opposite the pouch (40), the second support element being configured to facilitate piercing of the pouch (40).