FR3076705A1 - BODY MONITORING SYSTEM WITH DOUBLE FOAM - Google Patents

Abstract

The invention relates to a device (3) for body monitoring, comprising a fluid circuit (20) on which are disposed means for transdermal sampling (25) of body fluid, an absorbent foam (21 B), called measuring foam, characterized in that the device further comprises a discharge foam (21 C) in fluid connection with the measuring foam (21 B), the measuring foam (21 B) being positioned in the fluid circuit between the transdermal sampling means (25) and the discharge foam, the discharge foam having a hydrophilicity different from the measuring mouse (21 B).

Description

Body monitoring system with double foam

GENERAL TECHNICAL AREA

The present invention relates to microfluidics. More specifically, it relates to a body monitoring system via analysis of body fluid, typically interstitial.

STATE OF THE ART

Certain pathologies such as diabetes require daily monitoring of biochemical parameters of the human body, i.e. concentrations of certain compounds (blood sugar in the example of glucose).

For this, it is common to prick a point on the skin so as to make a drop of blood pearl, and to analyze this drop either reactively (for example with a strip) or electronically (for example by less than one analytical sensor), so as to estimate the target parameter (s).

Today we know much less invasive advanced systems that simply analyze the interstitial fluid, that is to say the fluid that fills the space between blood capillaries and cells. It has an ionic composition close to that of blood plasma.

These advanced systems thus make it possible to monitor the desired biochemical parameters transcutaneously, that is to say without the need to regularly pierce the skin and take a sample.

In particular, a device worn on the wrist called GlucoWatch has been proposed, implementing a phenomenon called iontophoresis (or iontophoresis) in which an electric field makes it possible to "attract" the interstitial fluid through the skin to a sensor on the device wall. However, this concept was quickly abandoned because only 6% of patients endured the pain of electrical extraction. In addition, the measurement results were unreliable.

Transcutaneous probes have been proposed alternately, taking the form of a self-adhesive patch plating a "needle sensor" just under the skin, so as to put the sensor in permanent fluid communication with the interstitial fluid, for continuous monitoring.

Some of these transcutaneous patch type probes include wireless communications means making it possible to trace the measurements on the interstitial fluid, for example to a mobile terminal, for storage and processing (verification of thresholds and variations, production of statistics, triggering of alerts if necessary, etc.). Examples include sugarBEAT ™ or FreeStyle Libre systems.

Such systems are satisfactory (the patches are much more reliable and less painful than iontophoresis devices), but prove to be restrictive and expensive because of the single-use patch which must be changed regularly. In addition, the patches tend to peel off, tear off when you change your clothes or make sudden movements, and are very visible: the wearer can be stigmatized as "sick".

It would be desirable to have an alternative portable electronic system which avoids the use of patches, painlessly, and without there being any hygienic risk.

Another difficulty comes from the lifetime of the sensors. The latter depends on several factors, among which we can mention the enzymes (living matter deteriorates the sensors), the protective layers, the manufacturing processes of the sensors, the external parameters and the conditions of use of the sensors (oxygen supply , immersion, etc.).

Currently, systems incorporating bio-chemical sensors to analyze from interstitial fluid proceed in the following different ways.

A variant uses a microfluidic tube, in which the liquid circulates by capillary action, until it comes into contact with the sensor. Circulation is thus continuous.

Another variant uses micro-needles which swell with liquid once inserted into the client's skin. The liquid is then sucked into a hydrogel which is in contact with the sensors.

Another variant uses sensors directly deposited on micro-needles.

In all of these solutions, the lifetime of the sensors is too short to justify economic viability. In fact, the sensors are permanently in contact with the fluid, which damages them.

Another difficulty comes from the difficulty in managing the flows of fluid, in particular the displacement of the interstitial liquid towards the sensor.

Some devices use a microfluidic tube in which the liquid circulates by capillary action and comes into contact with the sensors (cannula directly in the arm, then microtube to the sensors). Circulation is continuous and the liquid / sensor contact is permanent. After passing the sensors, the liquid ends up in a trash can.

Other devices use micro needles which, when inserted into the patient's skin, swell with liquid. This liquid is then sucked into a hydrogel itself in contact with the sensors. In this solution the sensors are still in constant contact with the liquid. After passing the sensors, the liquid diffuses into the hydrogel and gradually evaporates in a buffer zone.

PRESENTATION OF THE INVENTION

The present invention therefore relates to a body monitoring device, comprising a fluid circuit on which are arranged means for transcutaneous sampling of body fluid, an absorbent foam, called measuring foam, characterized in that in which the device further comprises an evacuation foam in fluid connection with the measurement foam, the measurement foam being positioned in the fluid circuit between the transcutaneous sampling means and the evacuation foam, the evacuation foam having a hydrophilicity different from the mouse of measured.

Body fluid can be interstitial fluid or blood, for example.

The device can include the following characteristics, taken alone or in combination:

- the fluid circuit also comprises at least one sensor for a physical quantity of body fluid, the measurement foam being configured to be in contact with the sensor in order to measure a physical quantity of the fluid absorbed by the measurement foam,

- the evacuation foam has a higher hydrophilicity than the measurement foam,

- the evacuation foam includes a controllable hydrophilicity,

the device comprises heating means such as a resistor for heating the evacuation foam in order to control the hydrophilicity of the evacuation foam,

the device comprises n juxtaposed foam, n being greater than or equal to two, each foam being more hydrophilic than the previous one,

the device comprises, for at least one foam, electrodes in order to measure the conductivity of said foam,

- the measuring foam is mounted movable between:

a measurement position, in which the measurement foam is in contact with the sensor, and a rest position, in which the measurement foam is not in contact with the sensor;

the device is configured so that, in the rest position, the measuring foam can be filled with liquid withdrawn from the transcutaneous withdrawal means,

the transcutaneous sampling means comprise needles, and in which, in the rest position, the measuring foam is in contact with one end of the needles,

- the device includes a passive mechanism attached to the measuring foam, the passive mechanism being configured to move foam between the two positions when it is activated,

- the evacuation foam is configured to be in contact with the measurement foam both in the measurement position and both in the rest position.

The invention also relates to a capsule comprising a device as described above.

The capsule may include a window with a filter membrane in order to vent the foams

The invention also relates to a system comprising:

- a device or a capsule as described above,

- data processing means configured to process measurements acquired by said sensor.

The system can include the following features, taken alone or in combination:

- the data processing means are configured to control the heating means,

the system comprises an active mechanism for controlling the passive mechanism and in which the data processing means are configured to control the active mechanism,

- the system comprises a housing, a capsule as described above, configured to engage with the housing in a removable manner,

- the housing comprises means for attaching to the reusable body, configured to maintain the means for transcutaneous sampling in contact with the skin.

PRESENTATION OF THE FIGURES

Other characteristics and advantages of the present invention will appear on reading the following description of a preferred embodiment. This description will be given with reference to the appended drawings in which:

FIG. 1 illustrates a diagram representing a system comprising a capsule, a housing and a patch disposed on the capsule,

- Figures 2a to 2c show three-dimensional views of the engagement of the capsule in the housing,

- Figures 3a, 3b, 3c illustrate three-dimensional views of the capsule.

- Figure 4 illustrates a sectional view of an embodiment of the system,

FIGS. 5a, 5b, 6a, 6b, 7a, 7b illustrate different variants of passive and active mechanisms for moving the measuring foam, and different variants of evacuation foam,

- Figure 8 illustrates in particular an embodiment relating to the evacuation foam.

DETAILED DESCRIPTION

General architecture

Referring to Figure 1, and Figures 2a, 2b and 2c, which show a general diagram, the present invention relates to an electronic body monitoring system 1.

By bodily monitoring is meant the verification of biochemical constants of a person carrying system 1, typically the concentration of a protein, a hormone, a marker, oxygen, nutrients, etc., in the interstitial fluid of the person. We will cite the example of blood sugar. The person skilled in the art will be able to monitor other physical physical quantities such as temperature, hydration, etc. if necessary.

The description will be illustrated with interstitial fluid but applies to other body fluids such as blood.

As will be explained later (see Figures 2a to 2c), the system can be separated into two modules: a housing 2 and a capsule 3 (Figures 3a to 3c). The term device will be used for the capsule.

The device 3 thus comprises at least one sensor 24 of a physical quantity of the body fluid, such as interstitial fluid, in particular a sensor of “bio-chemical” nature, that is to say allowing the analysis of the interstitial fluid. in particular by detecting a compound for example by means of several electrodes in contact with the interstitial liquid, and advantageously at least a second sensor such as a temperature sensor making it possible to adjust the analysis of the interstitial liquid sampled (taking into account the viscosity of the fluid depending on the temperature).

The system 1 also comprises data processing means 11 (in particular a processor or a microcontroller) configured to process measurements acquired by the sensor 24, and where appropriate data storage means 12 (in particular a memory, in particular of the flash type, and / or the memory of the microcontroller) making it possible for example to store these measurements, and / or a date of the first use of each sensor 24 to calculate an expiration date of the sensor (s) 24 (the biochemical sensors have a limited life). The data processing means 11 also serve to generate instructions to different components. Within the framework of this description, these various functions are provided by the same unit. However, it is possible to provide dedicated processors. The system 1 also comprises a battery for the electrical supply of the components, advantageously rechargeable, for example via port 10 (which it is understood that it can also be used to connect the system 1 for example to a computer to download the acquired data and / or processed).

Preferably, the system 1 can comprise wireless connection means (in particular of the WiFi type, but also Bluetooth, or even 3G / 4G) for connection to a network, in particular the internet, and a user interface such as a screen, possibly touch to display the monitoring results to the user.

It will be understood that a person skilled in the art knows algorithms for processing sensor measurements 24 and associated interfaces, and will know how to implement them in the present system 1.

Fluid circuit

The device 3 comprises a fluid circuit 20 on which are arranged means for transcutaneous sampling 25 of body fluid, for example interstitial fluid, said sensor 24, an absorbent foam 21B called measurement foam. The absorbent foam 21B can act as a pump for aspirating the interstitial liquid by the transcutaneous sampling means 25.

In a variant, the foam 21B is mobile. This will be detailed later.

In a variant, the device 3 comprises another foam, upstream, called intermediate foam 21 A, between the transcutaneous sampling means 25 and the measurement foam 21 B. This will be detailed below.

The device 3 comprises another foam, downstream, called evacuation foam 21 C, so that the measurement foam 21B is located between the transcutaneous sampling means 25 (or the intermediate foam 21 A, if present) and the foam 21 C.

Said transcutaneous interstitial fluid sampling means 25 advantageously consist of a network of micro-needles in contact with the skin when the device 3 is placed on the body of a person (see how below). Typically, micro-needles painlessly remove interstitial fluid from the dermis without bleeding.

Preferably, said transcutaneous sampling means 25 comprise between four and sixteen micro-needles (in particular four, nine or sixteen in the form of a square), substantially pyramidal, with tips of a height between 0.3mm and 0.8mm, each with a hole with a diameter between 0.04 and 0.22mm. Each of these advantageous characteristics of micro-needles can be taken separately or in combination with the others.

An absorbent foam (either foam 21A if it is present, or foam 21 B) causes transcutaneous extraction (through the epidermis) via the transcutaneous interstitial fluid removal means from the body (the dermis under the epidermis ), its circulation through the circuit 20 until it arrives at the level of the measurement foam 21B thus allowing it to be stored. Finally, this foam is brought into contact with the sensor 24 which will analyze the interstitial liquid. The liquid is evacuated from the foam by evaporation (the foam is advantageously in exchange with the atmosphere, in particular through a fabric which is porous to gases, so as to allow this evaporation, but advantageously impermeable to liquids (for example at polytetrafluoroethylene base) so as to avoid the penetration of liquids such as sweat from the outside).

The mobility of the foam

In one embodiment, the measurement foam 21B is movably mounted in the device 3. It can take a measurement position, in which the measurement foam 21B is in contact with the sensor 24 and a rest position, in which the measuring foam 21B is not in contact with the sensor 24.

By contact is meant a position in which the sensor 24 can analyze the body fluid stored in the measurement foam 21 B.

Thanks to this mobility, the sensor 24 is no longer permanently in contact with body fluid, which significantly increases its lifespan. It is even in contact with it only for the duration of the measurement. Thus, its lifespan is optimized.

Due to the movement, the measuring foam 21B in fact takes an infinite number of positions, but only the two aforementioned are useful.

In order to allow the foam to move (in addition to the natural movement of the foam when it is filled with liquid or when it is empty), the device 3 comprises a passive mechanism 50 which manages the movement. The measuring foam 21B is integral with this passive mechanism 50.

This passive mechanism 50 is configured to be connected to an active mechanism 60, called the actuator. When the movement is transmitted mechanically, a connection 70 forming an interface is provided. The link 70 may include an input socket mounted on the passive mechanism 50 and an output socket mounted on the active mechanism 60. This interface is visible in FIGS. 2a, 4 and 8: a male socket 72 is mounted on the housing 2 and a female socket 74 is mounted on the capsule 3, with a funnel or cone shape to guide (the reverse is also possible).

In this embodiment, the male connector 72 can be a shaft.

One way to engage the capsule 3 in the housing 2 is explained at the end of the description. In this way, the male connector 72 is conveniently positioned on the side wall of the bottom of the cavity C (see FIG. 2a).

If the engagement is done differently, the interface 70 can be located in other places. In fact, in view of the different ways of making the interface 70 and with the possibilities of angle, angle transmission, etc. offered by the passive mechanism 50 and the active mechanism 60, other configurations are open.

The passive mechanism 50 can take several forms and will be described later. Likewise, the active mechanism 60 can take several forms, depending on the passive mechanism 50 and will be described later.

The active mechanism 60 is controlled by the data processing means 11.

A stop 51 makes it possible to determine the maximum amplitude of movement of the measuring foam 21 B, in particular to ensure that it is in the ideal position for the sensor 24 in the case where the passive mechanism 50, the passive mechanism 60 , the link 70 or the control of the data processing means 11 has an imprecision (due to play, wear, conditions of use, etc.), or even a partial failure.

In the rest position, the measuring foam 21B can be filled with liquid sampled from the transcutaneous sampling means 25, via the intermediate foam 21A if it is present. This means that in the rest position, the measuring foam 21B is in fluid connection 40 with the transcutaneous sampling means or, if present, the intermediate foam. The fluid connection is made either by direct contact, or via an interface (several tubes, etc.).

Once the measuring foam is filled with liquid, the data processing means 11 activates the active mechanism 60 which, via the link 70, activates the passive mechanism 60 which allows the measurement foam 21B to pass into the measuring position .

Several ways of moving the measuring foam 21B will be described. We define for this a sensor plane, which corresponds to an effective surface of the sensor, that is to say a surface which must be in contact with the measuring foam 21 B.

- By translation

The measuring foam 21B can be driven in translation by the passive mechanism 50. The translation can be done either in the direction of the plane of the PC sensor (preferred), or parallel to the plane of the PC sensor.

In the first case (in the direction of the plane of the sensor), the foam 21B is moved away from the plane of the sensor 24 in the rest position and, after translation in approach towards the plane, is in contact with the latter (FIG. 5a)

In the second case (parallel to the plane of the sensor 24), the contact surface of the foam 24 remains substantially in the plane of the sensor 24. The translation first partially brings the foam 21B into contact with the sensor 24, then as continuous translation, totally in contact with the sensor 24 (FIG. 5b). To ensure contact, the foam 21 must gradually deform as it faces the plane of the sensor 24. The transcutaneous sampling means 25 and the surface of the sensor 24 are then not opposite.

In two variants illustrated in Figures 5a and 5b (for the two translations described above), the passive mechanism 50 is a rack and the active mechanism 60 is a pinion (which can be reversed). The link 70 is then formed by the meshing between the rack and the pinion. An electric motor drives the pinion in rotation.

In a variant not illustrated, the passive mechanism 50 is a magnetic part (that is to say sensitive to the magnetic field) and the active mechanism 60 is an electromagnet.

In a variant not illustrated, the passive mechanism 50 is a hydraulic or pneumatic cylinder and the active mechanism 60 is a pump.

- By rotation

The measuring foam 21B can be driven in rotation by the passive mechanism 50. The rotation can either take place along an axis orthogonal to the plane of the sensor PC (FIG. 6a) or an axis parallel to the plane of the sensor 24 (FIG. 6b, 7a, 7b).

In the first case, the sampling means 25 and the plane of the sensor 24 are not opposite and the rotation of the foam

In a variant illustrated in FIGS. 6a and 6b (for the two types of rotations described above), the passive mechanism 50 is a rod at one end of which is attached the foam 21B and at the other end of which is a socket for input, configured to receive the active mechanism 60. The input socket allows a rotation to be transmitted. The input mechanism is then typically an electric motor.

In a variant illustrated in FIGS. 7a and 7b, the passive mechanism 50 is a rod 52 with a fixed point 53 forming a pivot connection, said rod 52 being fixed at one end to the foam 21B and the other end comprises a socket input in the form of a funnel or a cone 74, configured to receive the active mechanism 60 which is capable of putting the rod 52 in rotation around its fixed point 51, the rod then functioning as a lever for raising or lowering the foam 21 B. In a variant illustrated in FIG. 5a, the active mechanism 60 then comprises a rod 62, with a fixed point 63 forming a pivot connection: one end 72 of the rod 61 can be engaged in the cone 74. In a variant illustrated in FIG. 7b, the active mechanism 60 and the rod 61 operate in translation (typically a jack or a crank mechanism - no fixed point therefore).

In all the variants of FIGS. 5a, 5b, 6a, 6b, 7a the active mechanism 60 operates in rotation (for example an electric motor).

The embodiments which tend to compress the measuring foam 21B on the sensor 24 are preferred because they ensure better immersion of the sensor 24.

Evacuation foam

The evacuation foam 21C is preferably always in contact with the measurement measurement foam 21 B, whether the latter is mobile (as described above) or immobile.

For this, when the mobility of the foam 21B is done away from or in approach in a direction orthogonal to the surface of the sensor, the foam 21C can be placed next to the foam 21 B, that is to say offset by relation to the orthogonal direction as illustrated in FIGS. 6b and 7b and 8,

The exhaust foam 21C has a different hydrophilicity than the measurement foam.

Hydrophilicity is the physical quantity of the foam which manages its capacity to absorb fluid or not. Therefore, when two foams are fluidly connected, the more hydrophilic foam will tend to pump the fluid from the less hydrophilic foam.

An improved system for managing the circulation of the fluid is thus obtained, with in particular a means of rapidly, simply and efficiently removing the liquid from the measuring foam 21 B.

The exhaust foam 21C preferably has a variable hydrophilicity to order. We'll talk about controllable hydrophilia. For this, heating means 46 such as a radiator or a resistor make it possible to heat the foam 21C and to increase its hydrophilicity: it then pumps the liquid contained in the measurement foam 21 B. The displacement of liquid is done by capillarity. The heating means 46 can be controlled by the data processing means 11.

When the measuring foam 21B is in the rest position, after a sufficiently long time, there is a fluid equilibrium between the interstitial fluid of the human body and all the foams 21 A, 21 B, 21 C. The circulation therefore does not take place not one way only. Thus, by heating the foam 21 C, it causes a new aspiration of interstitial liquid in the skin.

In the same way, by heating, it allows a purging of the system, useful after an absence of use.

Intermediate foam

With the intermediate foam 21A, the hydraulic circuit can comprise at least two successive foams in series.

The intermediate foam 21A provides a buffer between the transcutaneous sampling means 25 and the measurement foam 21 B.

It is also possible to provide N successive foams in series. In particular, it is possible to provide heating means on all the foams minus one (that which is in contact with the sensor 24), in order to more finely control the movement of fluid.

Preferably, each foam is more hydrophilic than the next (in the direction of the sampling means towards the last foam) so that the foam 21B is more hydrophilic than the foam 21A and the foam 21C is more hydrophilic than the foam 21 B.

Foam conductivity measurement

In order to know if the foam 21B is filled with liquid, the device 3 can comprise a conductimeter comprising electrodes 44 for measuring conductivity and an electric signal generator 14 is used. It is controlled by the data processing means 11.

The electrodes 44, one positive and one negative, are in contact with the foam, for example by sinking slightly into it. By measuring their conductivity, obtained by the application of an electrical signal, we can know if the foam is filled with liquid.

In the figures, the conductivity measurement is made on the intermediate foam 21 A. This is justified by two reasons: the first is linked to the fact that the measurement foam 21B is mobile. Consequently, implementing two electrodes in it is more complex. The second reason is related to the fact that the communication between the two foams 21A and 21B does not present any particular difficulty. In practice, these two foams 21A and 21B (when the foam is in the rest position) are in a state of fluid equilibrium. Therefore, it is considered that if the interstitial liquid could have risen to the intermediate foam, then the measurement foam 21B is also filled with liquid. However, it is also possible to carry out the conductivity measurement on the mobile measuring foam 21B (not shown).

Foam design

The foams can be made using two stacked membranes comprising fabric.

Capsule

Unlike known systems, system 1 is integral. This means that there is not a main module such as a mobile terminal connected wirelessly to a bulky and expensive secondary module (due to the need to equip it with a battery, wireless communication means , etc.) taking the form of a patch stuck to the skin. System 1 is thus autonomous.

To be used, it is either pressed against the skin if necessary by the user for a few seconds (it is in this case devoid of any means of attachment to the body), or directly worn on the body, in particular on a limb, and preferably on the wrist. The system 1 then takes for example the shape of a watch, with a face F against the skin of the arm, and an opposite face accommodating for example a screen.

As such, it advantageously comprises means for attaching to the reusable body, typically consisting of a strap or bracelet configured to surround the member (and not a sticky element), in particular a watch strap. "Reusable" means here as opposed to "single use" as was the case with patches, which cannot be reused after being peeled off and must be discarded. A bracelet can be opened and closed many times.

The system 1 is configured so that when it is placed on the skin (ie when the attachment means fix it to the body) the transcutaneous sampling means 25 are held against the skin (or at least in the immediate vicinity) to allow the sample.

In all cases, system 1 contains two subsets:

- the housing 2 in which are arranged at least the data processing means 11 and the active mechanism 60 (as well as the main components such as the battery, the memory, the possible user interface, etc.);

- the capsule 3 in which the sensor 24, the foams 21 A, 21 B, 21C are arranged (as explained preferentially in exchange with the atmosphere to promote the evaporation of the fluid and thus limit its stagnation, if necessary via a window 26 through the capsule 3 and a filter membrane) and the transcutaneous sampling means 25, the capsule 3 being configured to engage with the housing 2 in a removable manner. The capsule 3 preferably engages in a cavity C of the housing 2 located on its face F intended to be in contact with the skin.

In other words, and as can be seen in FIG. 1 and FIGS. 2a2c which represent a preferred embodiment, the system 1 remains composed of two modules 2, 3 but the latter are not physically separated as could be be the case in the prior art and are even in direct, mechanical connection.

The function of the interface 70 is to ensure the transmission between the capsule (where the passive mechanism is located 50) and the housing (where the active mechanism is located).

The box 2 and the capsule 3 for this purpose comprise transmission means for transmitting electrical signals, such as wireless connections (transmitter / receiver) without contact or electrical connectors 12a, 12b (contacts) which are particularly seen. in FIGS. 2a and 2b, configured so that when the capsule 3 is engaged with the housing 2, said electrical connectors 12a, 12b provide a connection between the data processing means 11 and the sensor 24 (for raising the measurement data) .

The capsule 3 thus constitutes an interchangeable sub-assembly of the system 1 which can be chosen according to the type of monitoring desired. Indeed, insofar as the capsule contains the sensor (s) 24, changing the capsule makes it possible to change sensors 24 if they are at the end of their life or if one wishes to change the physical quantity measured, in a simple manipulation , fast and safe, without having to throw away other parts (in particular the box 2). It is noted in this respect that the capsule 3 very effectively preserves the sensors 24, and needs to be changed less often than a patch (the same capsule can be used for a month).

And since capsule 3 contains neither a "pump" (in the traditional sense of the term), nor advanced electronic equipment such as a battery or wireless communication means, it is significantly less expensive than a patch.

The present system is therefore much more practical than the systems known from the prior art, but above all much less expensive to use, without there being the slightest hygienic risk, and without pain due to the insertion of a needle or strong electricity.

The capsule 3 is the only part of the system 1 which can be in contact with interstitial liquid, since it contains the absorbent foams 21 A, B, C (beyond which the withdrawn fluid cannot rise). Thus, the removable capsule prevents contamination of the housing 2 and makes it possible to be able to replace the capsule 3 at the end of the life of the sensors 24 or change the type of capsule 3 in a simple, rapid and safe handling, without having to throw away other parts.

Capsule change

The capsule 3 engages with the housing 2 in two successive translational movements T1 and T2 (Figures 2a to 2c and 4). The reverse movement makes it possible to disengage the capsule 3. The first movement T1 consists in bringing the capsule 3 towards the housing 2 to attach the electrical connectors 12a / b and the second movement T2 consists in sliding the capsule 3 along the housing 2 to engage the mechanical connection 70. The electrical connections 12a / b are flexible (with spring for example). In this configuration, the inside of the cone or of the funnel 74 is easily understood to guide the male connector 72 and produce the interface 70.

In addition, thanks to stops 3a (FIGS. 3a and 3c), once the translation T2 has been carried out, the capsule 2 is blocked in the direction of the translation T1. These stops 3a are wedged between the bottom of the cavity C and a rail 2b (Figure 2a).

Other general architecture

In another embodiment, the device does not include a sensor 24. The device therefore serves to collect body fluid without necessarily analyzing it.

Thanks to the system presented (according to the two architectures), it is possible to withdraw more than 4 μΙ of interstitial fluid without causing unacceptable pain in the user.

Claims (13)

1. Device (3) for body monitoring, comprising a fluid circuit (20) on which are arranged means for transcutaneous sampling (25) of body liquid, an absorbent foam (21 B), called measurement foam, characterized in that the device further comprises an evacuation foam (21 C) in fluid connection with the measurement foam (21 B), the measurement foam (21 B) being positioned in the fluid circuit between the transcutaneous sampling means (25) and the evacuation foam (21 C), the evacuation foam (21 C) having a hydrophilicity different from the measuring mouse (21 B). 2. Device (3) according to claim 1, wherein the fluid circuit further comprises at least one sensor (24) of a physical quantity of body fluid, the measuring foam (21 B) being configured to be in contact with the sensor (24) in order to measure a physical quantity of the fluid absorbed by the measuring foam (21 B), 3. Device (3) according to claim 1 or 2, wherein the discharge foam (21 C) has a higher hydrophilicity than the measurement foam (21 B). 4. Device (3) according to any one of the preceding claims, in which the evacuation foam (21 C) comprises a controllable hydrophilicity. 5. Device (3) according to the preceding claim, comprising heating means (46) such as a resistor for heating the evacuation foam (21 C) to control the hydrophilicity of the evacuation foam (21 C) . 6. Device (3) according to any one of the preceding claims, comprising n juxtaposed foam, n being greater than or equal to two, each foam being more hydrophilic than the previous one. 7. Device (3) according to any one of the preceding claims, comprising for at least one foam (21 B), a conductivity meter (44) in order to measure the conductivity of said foam. 8. Capsule comprising a device (3) according to any one of claims 1 to 7. 9. Capsule according to the preceding claim, comprising a window (26) with a filtering membrane in order to put the foams in the open air. 10. System comprising: - a device according to any one of claims 1 to 7 or a capsule according to claim 8 or 9, - data processing means (11) configured to process measurements acquired by said sensor. 11. The system as claimed in claim 10, in which the data processing means (11) are configured to control the hydrophilicity of the evacuation foam (21C) as defined in claim 3 or 4. 12. System according to any one of claims 10 to 11, comprising - a housing (2), - a capsule according to claim 8 or 9, configured to engage with the housing (2) removably. 13. The system of claim 12, wherein the housing (2) comprises reusable body attachment means configured to maintain the transcutaneous sampling means (25) in contact with the skin.