Body monitoring device including enhanced electrical contacts

Abstract

The invention relates to a body monitoring device, comprising: - a housing (2) having a lower face (21); - a sensor (3) having an upper face (32) arranged opposite the lower face (21) of the housing (2), the housing (2) being electrically connected to the sensor (3) via at least one connector (7), each connector (7) having a female portion (71) formed within the thickness of the sensor (3) and a male portion (72) projecting from the lower face (31) of the housing (2), the female portion (71) having a concave receiving orifice (73), said orifice (73) being such that when the male portion (72) is inserted into the orifice (73), the possible contact area between the male portion and the orifice is maximized in the event of relative displacement between the male and female portions. Figure for the abstract: FIGURE 1

Description

Title of the invention: Body monitoring device comprising improved electrical contacts Technical field

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

[0002] Monitoring of many known chronic diseases in humans requires daily recording of biochemical parameters. A concentration level of a body analyte in a body fluid of the organism, for example in blood plasma or in the interstitial fluid of the cells of the organism, can be recorded.

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

[0004] A widespread solution for monitoring diabetes consists of performing a puncture, for example at the tip of the finger, to collect a drop of blood, then performing a daily measurement of blood sugar in the drop of blood thus obtained.

[0005] Monitoring systems have been proposed to eliminate the need for manual puncture, so as to make blood glucose measurement less laborious and less invasive. These are called CGM systems, for "Continuous Glucose Monitoring". Some of these CGM systems perform, at regular intervals, a blood glucose measurement at the level of the interstitial fluid between the skin cells. The blood glucose level in the interstitial fluid is very close to the blood glucose level in blood plasma. Measurements at the level of the interstitial fluid allow simple and minimally invasive monitoring of patients' blood glucose levels; these measurements can be carried out using needle sensors, transcutaneously, or non-invasively, such as by iontophoresis or implantable with a measurement by chemo-fluorescence.

[0006] The international application published under number WO 2018 / 104647 describes a body monitoring system, usable in particular for monitoring blood sugar levels. This monitoring system includes an electronic watch attachable to the wrist using a bracelet. The watch comprises a case, into which is inserted an interchangeable removable capsule comprising a micro-needle sensor. The sensor is automatically controlled by the electronics of the case, to carry out a transcutaneous measurement. The blood sugar measurement by the sensor is an electrochemical measurement.

[0007] The device comprises connectors which allow the sensor to be electrically connected to the housing, in particular each connector comprises a male part arranged on the housing and a female part arranged on the sensor. However, when such a device is worn on the wrist, the connection between the sensor and the housing may be fluctuating given the differences in the insertion of the needles into the skin or given the movements of the user's wrist. Thus, the connection between the sensor and the housing may be imperfect, which may impair the measurements and therefore the monitoring. Statement of the invention

[0008] The invention proposes to overcome at least one of these drawbacks and proposes, for this purpose, a body monitoring device, comprising:

[0009] - a housing comprising a lower face;

[0010] - a sensor comprising an upper face arranged opposite the lower face of the housing, the housing being electrically connected to the sensor via at least one connector, each connector comprising a female part formed in the thickness of the sensor and a male part projecting from the lower face of the housing, the female part comprising a concave receiving orifice, said orifice being such that when the male part is inserted into the orifice the possible contact surface between the male part and the orifice is maximized in the event of relative movement between the male part and the female part.

[0011] The invention is advantageously supplemented by the following characteristics, taken alone or in any of their technically possible combinations:

[0012] - the orifice is spherical, or conical or truncated;

[0013] - the orifice has an opening angle of between 100° and 160°, preferably 130° ;

[0014] - the male part is a pin protruding from the lower face of the housing;

[0015] - the spindle comprises a fixed part attached to the housing and a movable part by relative to the fixed part, the pin being configured to allow movement of the movable part relative to the fixed part in a translation direction perpendicular to the upper face of the sensor;

[0016] - the pin comprises an elastic element attached to the movable part and to the fixed part of the spindle, the elastic element preferably being a spring;

[0017] - the male part consists of a spring blade extending from the internal face of the housing and is shaped to have a portion configured to be inserted into the orifice;

[0018] - the female portion is further configured to be connected to a connector electrically arranged on the lower part of the sensor;

[0019] - the female part is made up of a metal piece arranged throughout the thickness of the sensor, the metal part having a concave part above a conductive metal support;

[0020] - the female part further comprises a conductive track extending from the orifice towards the lower part of the sensor by traveling on the external surface of the sensor;

[0021] - the female part comprises a via which extends from the orifice into the thickness of the sensor;

[0022] - the device comprises at least one microneedle arranged on the lower face of the sensor. PRESENTATION OF FIGURES

[0023] 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:

[0024] - [Fig.l] schematically illustrates a device according to an embodiment of the invention in section;

[0025] - [Fig.2] schematically illustrates a device according to an embodiment in exploded view from a first point of view;

[0026] - [Fig.3] schematically illustrates a device according to an embodiment in exploded view from a second point of view;

[0027] - [Fig.4a], [Fig.4b] and [Fig.4c] illustrate several configurations of an orifice of a sensor of the device of the invention;

[0028] - [Fig.5a], [Fig.5b] and [Fig.5c] illustrate a comparison between a contact known type plan and an improved contact according to the invention;

[0029] - [Fig.6] illustrates a male pin-shaped part of a device according to the invention;

[0030] - [Fig.7] illustrates a male part in the form of a spring blade of a device according to the invention;

[0031] - [Fig.8a], [Fig.8b] and [Fig.8c] illustrate different possibilities for connecting the lower and upper faces of a sensor of a device according to the invention;

[0032] - [Fig.9] and [Fig. 10] illustrate the insertion of the male parts into holes of a device according to the invention.

[0033] Throughout the figures, similar elements bear identical references. DETAILED DESCRIPTION

[0034] In relation to figures 1, 2 and 3, a body monitoring device 1 comprises a housing 2, a sensor 3, an adhesive patch 4. Such a monitoring device 1 is advantageously used to implement a body monitoring method.

[0035] By body monitoring is meant the verification of biochemical constants of a person wearing the device, typically the concentration of a protein, a hormone, a marker, oxygen, nutrients, etc. in a bodily fluid of the person. For example, blood sugar can be mentioned. Those skilled in the art will also be able to monitor, if necessary, other physical bodily quantities such as temperature, hydration, etc.

[0036] The biochemical constant to be monitored is also considered to be 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.

[0037] Here, the body fluid is considered to be interstitial fluid, but other body fluids such as blood can also be considered.

[0038] The sensor 3 is 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.

[0039] 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. In addition, the microneedles are substantially pyramidal. The height of the microneedles is sufficiently low to avoid contact with a nerve of the wearer when the device is worn.

[0040] The micro-needles 5 make it possible to measure or sample the body fluid.

[0041] The microneedles 5 are hollow when it comes to sampling liquid or full to directly analyze the liquid. 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.

[0042] Advantageously, the sensor 3 comprises several microneedles which consist of a network of microneedles in that they are electrically connected to each other. The microneedles pierce the skin to come into contact with the interstitial liquid when the sensor is in contact with the skin.

[0043] As illustrated in [Fig.2], the sensor 3 is assembled to the adhesive patch 4 and together can constitute a capsule. The sensor 3 can also be removable from 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.

[0044] 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).

[0045] The sensor 3 therefore comprises elements which make it possible to sample the liquid or to bring the signals detected by each microneedle to the housing 2 for processing (not described here).

[0046] 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.

[0047] 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, extraction of data to a computer.

[0048] The case 2 is advantageously in the form of a watch case and comprises a bracelet 23 adapted to surround a person's wrist. The case 2 houses several elements making it possible to analyze or extract interstitial liquid. 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.

[0049] The electrical contact between the sensor 3 and the housing 2 is ensured by means of several connectors 7. These connectors 7 therefore make it possible to connect the sensor 3 to the housing 2. Indeed, the housing 2 must be able to recover information from the sensor 3 and must also be able to power it.

[0050] Each connector 7 comprises a female part 71 comprising an orifice 73 formed 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. The orifice advantageously has a depth of between 150 and 350, preferably 250

[0051] The orifice 73 is concave relative to the upper face 32 of the sensor 3 from which it is formed.

[0052] The orifice 73 can take several forms.

[0053] According to an embodiment illustrated in [Fig.4a], the orifice 73 is conical.

[0054] According to an embodiment illustrated in [Fig.4b], the orifice 73 is frustoconical.

[0055] According to an embodiment illustrated in [Fig.4c], the orifice 73 is spherical

[0056] Whatever the shape, the orifice 73 has an opening angle a between 100 and 140°C, preferably equal to 130°.

[0057] In the case of the spherical orifice 73 this angle a is taken between tangents D1, D2 to the orifice 73 and which start from the edges of the orifice 73.

[0058] The female part 71 advantageously comprises a conductive metal deposit 711 which coats the inside of the orifice 73. The orifice 73 can be formed over all or part of the thickness of the sensor 3. Each connector 7 is connected to one or more microneedles and / or to electrical tracks and / or to electrodes.

[0059] The receiving orifice 73 is therefore shaped in such a way that when the male part 72 is inserted into the orifice 73, electrical contact between the orifice 73 and the male part 72 is maximized in order to optimize the contact between the male part 72 and the female part 71 even in the event of displacement of the male part 72 in the orifice 73. Indeed, the male part 72 and the female part 71 are not mechanically connected to each other; the shape given to the orifice 73 compensates for this absence of mechanical connection by compensating in particular for the relative displacements of the male part 72 in the orifice 73.

[0060] As visible in Figures 5a, 5b and 5c, the provision of a concave orifice 73 allows movements of the male part 71 in the orifice 73 without the electrical contact being degraded. Indeed, between a plane contact (see [Fig.5a]) and a contact with the concave orifice 73, the contact surface is increased (see Figures 5b and 5c). For example, the contact surface (see below each of these figures), the contact surface with the spherical orifice is greater than that with a plane contact, the contact surface with the conical orifice is greater than that with the spherical orifice.

[0061] Indeed, when the device is attached to a user's wrist and the sensor 3 is attached to the skin by means of the adhesive patch, the housing 2 is attached to the sensor 3 and is held in position by the bracelet. And, given the position of the device around the wrist, it is understood that the pressure exerted by the housing on the sensor is not uniform so that the male parts do not sink in the same way into the different orifices. This is also due to the sinking of the microneedles which is not uniform. In addition, the movements of the device can cause the male parts to move. All these reasons lead to movements of the male parts relative to the female part and are compensated by the concavity of the orifice since the electrical contact is maximized. The connection provided by the connectors as described here is therefore robust.

[0062] According to one embodiment, the male part 71 is a pin in the form of a conductive metal cylinder and has a spherical section. In this way it can fit perfectly into the orifice.

[0063] Preferably, as illustrated in [Fig. 6], the pin comprises a fixed part 741 which is attached to the housing and a movable part 742 relative to the fixed part 741, the pin 74 being configured to allow movement 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 the pin 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 away from the fixed part than without biasing.

[0064] 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.

[0065] According to an embodiment illustrated in [Fig.7], the male part 71 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 have a part 751 configured to be introduced into the orifice 73. 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.

[0066] It is understood that the male part, because it comprises an elastic part (spring pin or spring blade), is configured to exert a force on the sensor so as to compensate for variations in the penetration of the microneedles into the skin or in the movements of the wearer's wrist. This is an additional compensation, the connection is all the better for it.

[0067] The orifice has a depth of between 0.2 mm and 0.9 mm, preferably 0.5 mm. The depth is adapted to the height of the male part which must be housed in the orifice.

[0068] In a complementary manner, the female part 71 is further configured to be connected to an electrical connector 33 arranged on the lower face 31 of the sensor 3. Such a connection makes it possible to electrically connect the upper and lower faces, in particular when a micro-needle or an electrode is connected to the electrical connector 33.

[0069] To connect the upper and lower faces, several embodiments are possible.

[0070] According to an embodiment illustrated in [Fig.8a], the female part 71 comprises a conductive track 711 extending from the orifice 73 towards the lower face 31 of the sensor 3 by traveling on the external surface of the sensor 3. In particular, the conductive track 711 travels to the electrical connector 33 arranged on the lower face of the sensor 3.

[0071] According to an embodiment illustrated in [Fig.8b], the female part 71 is constituted by a single metal part 712 arranged in the entire thickness of the sensor 3, the metal part 712 comprising a concave part above a conductive metal support, cylindrical or in the form of a rod.

[0072] According to an embodiment illustrated in [Fig.8c], the female part 71 comprises a via 713 which extends from the orifice throughout the thickness of the sensor 3 to the electrical connector 33 arranged on the lower face of the sensor 3. A conductive metal covers the via up to the electrical connector 33.

[0073] In operation, when the sensor 3 is brought towards the housing 2 (or vice versa) in order to connect them together, the male parts of the housing must be inserted into the holes. Given the concavity of the hole and their opening angle, the insertion of the pins into the holes is simplified.

[0074] This is illustrated in [Fig.9], the larger the opening angle of the orifices, the more the alignment errors are compensated. Indeed, as can be seen in this figure, we see the pins 74 which are above orifices whose opening angle is 45°. Orifices with an opening of 130° are shown below. It is immediately understood that the insertion of the pins will be possible in orifices having a wide opening. The phenomena of blocking the insertion due to a misalignment between the male parts and the orifices are therefore attenuated. This is visible in [Fig. 10] where we see that such concave orifices with a sufficiently wide opening make it possible to ensure electrical contact for insertions of the male parts into the orifices even if these male parts are inserted differently into the orifices.

Claims

Claims

1. Body monitoring device, comprising - a housing (2) comprising a lower face (21) and a bracelet (23) adapted to surround the wrist of a user; - a sensor (3) comprising a lower face (31), an upper face (32) arranged opposite the lower face (21) of the housing (2) and at least one microneedle (5) arranged on the lower face (31) of the sensor (3), - at least one connector (7) electrically connecting the housing (2) to the sensor (3), each connector (7) comprising a female part (71), the female part (71) comprising a concave receiving orifice (73) formed in the thickness of the sensor (3) and a male part (72) projecting from the lower face (31) of the housing (2), the orifice (73) being concave relative to the upper face (32) of the sensor (3) from which the orifice (73) is formed, - an electrical connector (33) arranged on the lower face (31) of the sensor (3),a micro-needle being connected to the electrical connector (33), the female part (71) being configured to be connected to the electrical connector (33) so as to electrically connect the upper and lower faces of the sensor (3), the orifice (73) being such that when the male part (72) is inserted into the orifice (73) the possible contact surface between the male part and the orifice is maximized even in the event of relative displacement between the male part and the female part.,

2. Device according to claim 1, in which the orifice (73) is spherical, or conical or frustoconical.

3. Device according to one of claims 1 to 2, in which the orifice (73) has an opening angle of between 100° and 160°, preferably 130°.

4. Device according to one of claims 1 to 3, in which the male part is a pin (74) projecting from the lower face (31) of the housing.

5. Device according to claim 4, in which the pin comprises a fixed part attached to the housing (2) and a part movable relative to the fixed part, the pin being configured to allow movement of the movable part relative to the fixed part according to a direction (Z) of translation perpendicular to the upper face (32) of the sensor (3).

6. A device according to claim 5, wherein the pin (74) comprises a resilient element attached to the movable portion and the fixed portion of the pin, the resilient element preferably being a spring.

7. Device according to one of claims 1 to 3, in which the male part (72) consists of a spring blade (75) extending from the internal face (21) of the housing (2) and is shaped to have a part (751) configured to be introduced into the orifice (73).

8. Device according to one of claims 1 to 7, in which the female part (71) is constituted by a metal part arranged in the entire thickness of the sensor, the metal part comprising a concave part above a conductive metal support.

9. Device according to one of claims 1 to 7, in which the female part (71) comprises a conductive track extending from the orifice towards the lower sensor part by running on the external surface of the sensor.

10. Device according to one of claims 1 to 7, in which the female part (71) comprises a via (713) which extends from the orifice into the thickness of the sensor.

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