BODY SURVEILLANCE DEVICE WITH IMPROVED CONTACTS

Description

TECHNICAL FIELD

[0001] The invention relates to a body monitoring device and in particular to a body monitoring device by analysis of body fluid, typically interstitial by means of microneedle(s). STATE OF THE ART

[0002] 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.

[0003] As a common example, monitoring a patient's diabetes requires accurate daily recording of the patient's blood sugar levels.

[0004] A common 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 blood sugar measurement in the drop of blood thus obtained.

[0005] 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, for "Continuous Glucose Monitoring." Some of these CGM systems measure blood glucose levels at regular intervals in the interstitial fluid between skin cells. Interstitial fluid glucose levels are very similar to blood plasma glucose levels. Interstitial fluid measurements allow for simple and minimally invasive monitoring of patients' blood glucose levels; these measurements can be performed using needle sensors, transcutaneously, or non-invasively, such as iontophoresis or implantable with chemifluorescence measurement.

[0006] 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 a removable interchangeable capsule comprising 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.

[0007] The device comprises connectors that allow the sensor to be electrically and physically connected to the housing, in particular each connector comprises a male part arranged on the housing and a female part arranged on the sensor. In particular, the connectors are spring-loaded in that the male part is elastic when it pushes into the female part. Such spring-loaded connectors make it possible to improve the connection, in particular when the connection between the sensor and the housing is fluctuating, taking into account differences in the insertion of the needles into the skin, for example, or taking into account the movements of the user's wrist.

[0008] Thus, the connection between the sensor and the housing may be imperfect, which can harm the measurements and therefore the monitoring, this imperfect connection generating measurement noise. An alternative device is disclosed in document EP 3136954 A2.

[0009] Furthermore, we know of physical contact connectors, as opposed to radio contact, which include two associated functions: a strong and stable mechanical holding function (clipping, force tightening) and an electrical connection function (metal contact). The fact of not having this strong mechanical holding function is problematic.

[0010] In fact, in this type of connector, the difficulty lies in the fact that the mechanical holding function is not fixed and strong, but loose and fluctuating since it depends on external parameters (change in the diameter of the wrist during the day, flexibility of the bracelet, shocks, etc.). STATEMENT OF THE INVENTION

[0011] The invention improves the connection between a sensor and a housing when the latter are loosely connected together by means of spring connectors, i.e. when there is no mechanical support at the connectors.

[0012] For this purpose, the invention provides a body monitoring device according to claim 1, the device comprising: a housing comprising a lower face; a sensor comprising a lower face intended to be arranged on a limb of a user and an upper face arranged opposite the lower face of the housing, the sensor and the housing being separable or detachable from each other on demand, no mechanical connection holding the housing to the sensor firmly together, the housing being in loose electrical and physical contact with the sensor via a plurality of connectors, each connector comprising a female part and a spring-loaded male part such that the male part exerts a force on the female part tending to move the housing away from the sensor or vice versa;the device further comprising means for attaching the housing to a limb of the user, said attachment means being configured to apply a clamping force in order to compensate for the force separating the housing from the sensor when the latter is attached to the limb of the user; ; the device being such that the connectors are distributed relative to a distribution zone defined on the upper face of the sensor or on the lower face of the housing, more than 70% of the connectors being distributed symmetrically in each half of the distribution zone relative to the center of the housing which corresponds to the epicenter of the force exerted by the attachment means.

[0013] The invention is advantageously supplemented by the following characteristics, taken alone or in any of their technically possible combinations: the male parts and the female parts of each connector are distributed in an identical and complementary manner on their respective faces; the male parts and the female parts of each connector are not distributed in an identical and complementary manner on their respective faces; the device comprises six to twenty connectors, preferably ten or twelve connectors distributed in the distribution zone, the distribution zone being polygonal or ovoid in shape, for example delimited by a circle, an ellipse or an oval, or is a portion of a polygon; the device further comprises zones comprising a male part and a female part, the female part being such that when the male part is inserted into the female part, the male part does not exert force against the female part; the connectors are connected together in groups of two to seven connectors, preferably three to four connectors;each connector comprises a female part formed in the thickness of the sensor and a male part projecting from the lower face of the housing; the male parts are pogo pins configured to allow an amplitude of between 50 µm and 2 mm inclusive when the sensor is in contact with the housing; the device comprises a removable connection between the sensor and the housing, the connection preferably being constituted by complementary magnetic parts arranged on the sensor and / or the housing; the sensor is configured to measure a physiological or biochemical quantity of the user, and preferably comprises at least one microneedle adapted to be inserted into the user's skin.

[0014] The distribution of the connectors improves the connection in the absence of mechanical support provided by the connectors.

[0015] Indeed, given that it is the attachment means which allow the sensor and the housing to be linked by bringing them together and therefore countering the force of the male parts, a good distribution of forces compensates for imperfect tightening of the attachment means and / or movements of the user's wrist. PRESENTATION OF THE FIGURES

[0016] 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 a sectional device according to one embodiment of the invention; the figure 2 illustrates a device in perspective according to an embodiment of the invention; the figure 3 illustrates a device from another perspective according to an embodiment of the invention; the figure 4 schematically illustrates a connector according to an embodiment used by the device of the invention; the figure 5 schematically illustrates a connector according to an embodiment used by the device of the invention; the figures 6a et 6b illustrate a distribution of the connectors of a device according to the invention according to one embodiment; the figures 7a et 7b illustrate a distribution of the connectors of a device according to the invention according to one embodiment; the figures 8a et 8b illustrate a distribution of the connectors of a device according to the invention according to one embodiment.

[0017] In all figures, similar elements have identical references. DETAILED DESCRIPTION

[0018] In relation to the figures 1, 2 And 3 , a body monitoring device 1 comprises a housing 2, a sensor 3, an adhesive patch 4.

[0019] Body monitoring means the verification of biochemical constants of a person wearing the device, typically the concentration of a protein, a hormone, a marker, oxygen, nutrients, etc., for example in a bodily fluid of the person. An example of this is blood sugar. A person skilled in the art may also monitor, if necessary, other physical bodily quantities such as temperature, hydration, etc.

[0020] It is preferred but not limited to that the biochemical constant to be monitored is the glucose (or blood sugar) concentration in the interstitial fluid of the skin. The blood sugar in the interstitial fluid is considered to be representative of the blood sugar in the blood plasma.

[0021] Here we consider the body fluid to be interstitial fluid but we can also consider other body fluids such as blood.

[0022] 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. 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 skin 6 of the wearer. 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.

[0023] 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.

[0024] Microneedles 5 are used to measure or collect body fluid.

[0025] 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.

[0026] 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.

[0027] As illustrated on the figure 2 , the sensor 3 is assembled to the adhesive patch 4 and can together constitute a capsule. The sensor 3 can also be removable relative to the patch 4. Such a capsule is advantageously removably mounted 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 further comprises an external face 32 opposite the internal face 31.

[0028] 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).

[0029] 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).

[0030] 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.

[0031] 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.

[0032] 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 case 2 houses several elements making it possible to analyze or extract 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 from microneedles in contact with a bodily fluid which may or may not be sampled.

[0033] The electrical contact between the sensor 3 and the housing 2 is ensured by means of several connectors 7 (or spring connectors). These connectors 7 allow the sensor 3 to be connected to the housing 2. Indeed, the housing 2 must be able to retrieve information from the sensor 3 and must also be able to power it. The connectors 7, as already mentioned, do not allow the sensor 3 to be mechanically linked to the housing 2.

[0034] Each connector 7 comprises a female part 71 comprising an orifice 73 formed for example in the thickness of the sensor 2 and a male part 72 projecting from a lower face 21 of the housing 2. It is specified that a lower face will be closer to the wrist than an upper face.

[0035] The orifice 73 is advantageously concave relative to the upper face 32 of the sensor 3 from which it is formed.

[0036] The connector 7 is spring-loaded in that the male part 72 when it is inserted into the female part undergoes a movement. In particular, the male part, because it comprises an elastic part (spring pin or spring blade), is configured to exert a force on the sensor tending to separate the housing 2 from the sensor 3 when they are connected together.

[0037] Preferably, as illustrated in the figure 4 ,the male part 72 is a pogo pin and comprises a fixed part 741 and a movable part 742 relative to the fixed part 741, the male part 72 being configured to allow a displacement of the movable part 742 relative to the fixed part 741 in a translation direction Z perpendicular to the lower face 21 of the housing 2. The movable part 742 is coaxial with the fixed part 741. In addition, an elastic element 743 such as a spring is fixed inside between the fixed part 741 and the movable part. Such a spring is a compression spring so that without biasing the pin in the Z direction the movable part is further from the fixed part than without bias. In the case of a pogo pin the spring to be compressed requires a force of 1 newton.

[0038] According to a preferred embodiment, the fixed part has a height of 2.5 mm and the movable part has a height of 0.6 mm. Still according to this preferred embodiment, the spring has a stiffness such that it allows the movable part to be inserted into the fixed part by approximately 0.3 mm. In particular, each pogo pin allows a translation of an amplitude between 50 µm and 2 mm inclusive when the sensor is in contact with the housing.

[0039] Alternatively, as illustrated in the figure 5 the male part 72 is constituted by a metal spring blade extending from the lower surface 21 of the housing 2. The metal blade 75 is advantageously shaped to present a part 751 configured to be introduced into or onto the female part 71 constituted by an orifice 73 (see the figure 1 ). This part 751 which is intended to be introduced into the orifice 73 is advantageously spherical. In addition, the blade 75 is made of conductive metal.

[0040] While using such connectors makes it easier to make the electrical connection between the box and the sensor and to compensate for wrist movements or imperfect tightening, it is necessary to be able to compensate for the force they exert.

[0041] This is because the housing 2 and the sensor 3 are loosely connected together in that no mechanical connection holds them firmly together.

[0042] To do this, the bracelet 23 allows this force to be compensated, but it is not enough on its own. Indeed, depending on how tightly the bracelet is tightened, the distribution of the forces it exerts on the case 2 will not necessarily be optimal.

[0043] Thus, it is expected that the connectors are distributed relative to a distribution zone ZR defined on the upper face of the sensor 3 and / or on the lower face of the housing 2 such that more than 70% of the connectors are distributed symmetrically in each half of the distribution zone ZR relative to the center of the housing 2 which corresponds to the epicenter of the force exerted by the bracelet 23. It is the male and female parts of the connectors which are distributed over the distribution zone ZR.

[0044] Thus, the connectors 7 which are used to connect the box 2 to the sensor 3 are distributed according to this distribution zone. The distribution zone ZR is polygonal or ovoid in shape. It can be delimited by a rectangle or a circle or an ellipse or an oval, etc.

[0045] In this way, the forces exerted by the connectors are compensated and the electrical connection between the housing 2 and the sensor 3 is optimized and low-noise.

[0046] With such a distribution it is possible to provide a large number of 7 connectors while limiting the measurement noise.

[0047] Advantageously, six to twenty connectors 7 are provided, preferably ten or twelve connectors.

[0048] For example, the bracelet exerts an optimal force at the center of case 2. This force is for example of the order of 20 N ± 4 N (depending on many parameters). This force reduces the further one moves away from the center of case 2 (approximately 18 N at 3 mm from the center, approximately 16 N at 5 mm, approximately 14 N at 7 mm, etc.). In addition, the greater the number of connectors in a tight area, the more their force accumulates and opposes the force of the bracelet in this area.

[0049] For example, each pogo pin is considered to exert a force of 1N which opposes that exerted by the wristband.

[0050] If in this case we have the pogos only on one side (for example, twelve pogos on one side) then we have about 12 N on one side, and therefore the bracelet exerts its force of 20N to 14N ±4 N (the connectors are not in the center of the case) which does not succeed in compensating enough to force a constant support of the pogos. The result is a loss of contact on certain spring connectors during shock or vibration of the wrist.

[0051] On the other hand, if we arrange six spring connectors around the center of the case 2, we obtain approximately 6N on each side, a force compensated by the bracelet which is 20 N to 14 N ±4 N.

[0052] Also, some connectors can be isolated because they therefore represent a weak force.

[0053] Also advantageously, the connectors 7 are connected together to carry out the measurements, one connector being associated with a microneedle so that the connections of the connectors mirror those provided for the microneedles.

[0054] However, if too many connectors are connected together, they become susceptible to noise caused by wrist movements or the fluctuating connection of the wristband. Therefore, the connectors are planned to be connected together in bundles of two to seven connectors, preferably three to four connectors.

[0055] Preferably, the connectors 7 are connected two by two and simultaneous measurements via these pairs of connectors are carried out.

[0056] According to one embodiment, the male parts are distributed on the lower face of the housing as visible in the figures 1, 2 And 3 .

[0057] According to another embodiment, the male parts are distributed on the upper face of the sensor (embodiment not shown).

[0058] Examples of distribution are described below.

[0059] THE figures 6a et 6b illustrate respectively a bottom view of the box 2 and a top view of the sensor 3. These figures illustrate a distribution of the symmetrical connectors in a zone ZR which is here a disk. On the figure 6a , the circles represent for example the male parts while on the figure 6b The circles represent the female parts. In these figures, eight connectors are distributed symmetrically over the ZR zone, on each half there is an identical number of connectors.

[0060] THE figures 7a et 7b illustrate another distribution of the connectors. In these figures eight connectors are distributed over the ZR zone, four connectors being on one half, three being on the other, one connector is outside the symmetry zone, six connectors out of eight are distributed symmetrically.

[0061] In a complementary manner, as described on the figures 8a et 8b ,Additional connectors may be provided (hereinafter contacts) and also include a male part and / or a female part. They are of identical technology to those of the connectors for the electrical contact between the sensor and the housing. These contacts are not intended for the connection of the housing 2 to the sensor 3 but are intended for example to recharge the housing, or to connect the sensor 3 to an external test system. So that they do not interfere with the distribution of forces thus described, it is provided that the female part associated with the male contact is an orifice which thus prevents any disturbing force between the housing and the connector. In the case of a pogo pin, in this case, a larger orifice can be provided than the female parts of the connectors dedicated to the connection between the housing and the sensor.

[0062] THE figures 8a et 8b illustrate for example male and female parts (empty circles) of the connectors useful for the sensor box connection and male and female parts (black circles) referenced by 81, 82 useless for this connection (for the contacts). If the male parts 81 are provided on the box 2 then the female parts 82 opposite are orifices such that the male parts simply push into the orifices without exerting any additional force.

[0063] On the methods of realization of the figures 6a, 6b , 7a, 7b There are as many male parts as female parts but we can predict that this is not the case. For example, as we can see on the figures 8a, 8bassuming that the female parts (open circles) are on the sensor, there are more female parts than male parts. Therefore, we can predict that the male parts and the female parts of each connector are distributed in an identical and complementary manner on their respective face or that they are not distributed in an identical and complementary manner on their respective face.

[0064] In a complementary manner, a removable connection 50 between the sensor and the housing makes it possible to improve the force exerted by the attachment means (the bracelet) and improve the connection between the sensor and the housing. This removable connection is for example constituted by complementary magnetic parts arranged on the sensor and the housing or by magnets 51 arranged for example on the sensor 3, the housing 2 then being metallic or magnetic.

[0065] This additional connection makes it possible to increase the mechanical force between the housing 2 and the sensor 3 and thus to increase the number of connectors.

Claims

1. Body, monitoring device comprising: - a case (2) comprising a lower face (21); - a sensor (3) comprising a lower face (31) intended to be arranged on a user's limb and an upper face (32) arranged opposite the lower face (21) of the housing (2), the sensor and the housing being separable from each other as required, no mechanical connection holding the housing (2) to the sensor (3) firmly together, the housing (2) being in loose electrical and physical contact with the sensor (3) via a plurality of connectors (7), each connector (7) comprising a female part (71) and a spring male part (72) so that the male part (72) exerts a force on the female part (71) tending to move away the housing (2) from the sensor (3) or vice versa; the device further comprising: - means for attaching (23) the case (2) to a limb of the user, said attaching means being configured to apply a clamping force in order to compensate for the force moving away the case (2) from the sensor (3) when the latter is attached to the member of the user; the device being such that the connectors are distributed with respect to a distribution zone (ZR) defined on the upper face (32) of the sensor or on the lower face of the casing (31), more than 70% of the connectors being distributed symmetrically in each half of the distribution zone (ZR) with respect to the centre of the casing, which corresponds to the epicentre of the force exerted by the attachment means (23).

2. The device as claimed in claim 1, comprising an adhesive patch (4) adapted to be glued to the skin, the patch (4) supporting the sensor and allowing the case (2) to be detached (2) without removing the sensor (3).

3. The device as claimed in one of the preceding claims, wherein the sensor (3) is configured to measure a physiological or biochemical quantity of the user and comprises at least one micro-needle adapted to be inserted into the user's skin.

4. The device as claimed in one of the preceding claims, wherein the sensor (3) engages in a cavity (21) in the case (2) on its side intended to come into contact with the user's skin.

5. The device as claimed in one of the preceding claims, wherein the male parts (72) and the female parts (71) of each connector are identically and complementarily distributed on their respective faces.

6. The device as claimed in one of the preceding claims, wherein the male parts (72) and the female parts (71) of each connector are not distributed identically and complementarily on their respective faces.

7. The device as claimed in one of the preceding claims, comprising six to twenty connectors, preferably ten or twelve connectors distributed in the distribution zone (ZR), the distribution (ZR) being zone polygonal or ovoid in shape, for example delimited by a circle, an ellipse or an oval, or is a portion a polygon.

8. The device as claimed in one of the preceding claims, further comprising zones (81, 82) comprising a male part and a female part, the female part being such that when the part male is introduced inserted into the into female, the male part is not exerts any force against the female part.

9. The device as claimed in one of the preceding claims, wherein the connectors (7) are linked together in groups of two to seven connectors, preferably three to four connectors.

10. The device as claimed in one of the preceding claims, wherein each connector (7) comprises a female part formed in the thickness of the sensor (3) and a male part (72) projecting from the lower face (31) of the casing (2).

11. The device as claimed in one of the preceding claims, wherein the male parts (72) are pogos pins configured to allow an amplitude of between 50 µm and 2 mm inclusive when the sensor (3) is in contact with the casing (2).

12. The device as claimed in one of the preceding claims, comprising a link (50) removable between the sensor (3) and the housing (2).

13. The device as claimed in one of the preceding claims, wherein the connection (50) is constituted by complementary magnetic parts arranged on the sensor and / or the casing.

14. The device as claimed in one of the preceding claims, wherein the case (2) is in the form of a watch case and comprises means (23) for attaching the device to a user's wrist.