A device that can be used by one person to analyze a biological fluid and the associated implementation method.
Patent Information
- Application Number
- FR2023014184
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-12-14
- Publication Date
- 2026-09-11
- Estimated Expiration
- 2043-12-14
AI Technical Summary
Existing electrochemical sensors for analyzing biological fluids, such as sweat, require laboratory-based calibration before use, which limits their ability to provide real-time, continuous, and long-term monitoring.
A portable device equipped with electrochemical sensors that includes a collection zone for biological fluids, a measurement zone with multiple sensors, a transport zone, and at least one cartridge filled with a calibration fluid, allowing for in situ calibration without external sampling.
Enables precise and reliable real-time measurements of biological fluids by allowing calibration to be performed directly on the device, improving accuracy and reducing the need for laboratory calibration.
Abstract
Description
Title of the invention: Device portable by a person for analyzing a biological fluid and associated implementation method. Technical field of the invention
[0001] The invention relates to devices for analyzing biological fluids that can be worn on a person. In particular, it relates to a device, capable of being worn by a person, equipped with electrochemical sensors for analyzing biological fluids. More specifically, the invention refers to the implementation of these devices and more particularly to their calibration. Technical background
[0002] Electrochemical sensors are devices that convert chemical signals into measurable electrical signals. Their basic principle is based on electrochemical reactions that occur at the interface between a sensitive material and a chemical solution. These reactions generate an electric current, a potential difference or a change in electrochemical impedance, which can be measured and used to quantify the concentration of a target substance. There are different types of electrochemical sensors, such as oxygen electrodes, pH electrodes, electrodes sensitive to selective ions or electrodes sensitive to specific chemical or biological species, each type of electrode will use a specific sensitive element.
[0003] The advantages of electrochemical sensors are their high sensitivity, selectivity and short response time. They are also relatively compact, easily integrated, inexpensive and easy to use. They are therefore widely used in many fields, such as water quality monitoring, gas analysis, industrial process control and medical devices.
[0004] Electrochemical sensors can therefore be naturally applied to the analysis of any type of biological fluid, in particular that of sweat. Indeed, sweat contains various substances, including electrolytes, metabolites or biomarkers, which can provide information on the state of health, hydration, metabolic activity and other physiological parameters of the person wearing the sensor. As an example, we can mention glucose, sodium and potassium ions, lactate or other relevant chemical or biochemical substances.
[0005] Electrochemical sensors for sweat analysis can be portable and non-invasive, making them convenient for real-time monitoring of health parameters during physical activities or in medical care. They can also be integrated into wearable devices, such as wristbands or patches, to enable real-time, continuous and long-term monitoring.
[0006] It should be noted that electrochemical sensors applied to sweat monitoring are under continuous development. Research in this field aims to improve the accuracy, sensitivity and reliability of these sensors, as well as to expand the range of analytes that can be measured.
[0007] A point of attention to be paid to electrochemical sensors and more particularly to those aiming to analyze a person's sweat is calibration. Calibration is indeed a necessary step to ensure the accuracy and reliability of the measurements. In general, several actions are necessary and commonly applied in the laboratory: preparation of the calibration solutions, cleaning of the sensor, zero adjustment, calibration, establishment of the calibration curve, verification and final adjustment (with for example a verification of linearity and precision).
[0008] In Figure 1 we present the case of a calibration curve of a potentiometric type electrochemical sensor which is defined by the relation [Maths 1] E = Eq + a.log( C ), where E is the measured potential difference, C is the analyte concentration, Eo is a calibration parameter (sometimes called "offset" in English) and a is the sensitivity of the sensor (expressed according to this equation in unit of potential per unit of decade of concentration).
[0009] One possibility is to perform a calibration close to the measurement with a single measurement in a calibration fluid (reference) mimicking the medium to be analyzed at a concentration sufficiently close to the target concentration. This makes it possible to consider that the sensitivity a is identical between the calibration fluid and the medium to be analyzed but to correct the value Eo. In order to better explain this strategy, we represent in [Fig.2], an example of measurement (measurements of Eb E2) which first passes a standard Mi (whose concentration Ci of the analyte of interest is perfectly known) and the sample M2 ("sample" in English) whose concentration C2 is to be determined. This approach makes it possible to do away with the value of Eo. It is necessary to know the value of the sensitivity a which is generally established by batch of manufactured sensors. This approach has its limits because over time, the value of the sensitivity a can change.
[0010] Another possibility is to perform a calibration close to the measurement with multiple measurements (at least two) with different calibration fluids. This also allows the value of the sensitivity a to be corrected. This approach can be particularly suitable in a complex environment such as biological fluids (sweat for example) because there may be the presence of interfering molecules which will lead to an overestimation of the measured concentration. Furthermore, certain physicochemical parameters such as conductivity, pH or temperature can impact the measurement.
[0011] Whatever the type of calibration considered, it is of the laboratory type, that is to say that it is done before the actual measurement.
[0012] In the particular field of sweat analysis, one can for example cite the study by Parrilla et al., “Wearable Potentiometric Ion Patch for On-Body Electrolyte Monitoring in Sweat: Toward a Validation Strategy to Ensure Physiological Relevance”, Analytical Chemistry 2019, vol. 91, pp. 8644-8651. (https: / / pubs.acs.org / doi / pdf / 10.1021 / acs.analchem.9b02126). This study proposes an electrochemical sensor device for potentiometric monitoring of pH, Cl, K+ and Na+, a device that is suitable for being worn by a person. This device comprises a flexible collection cell coupled to an analysis cell. The device is interesting because it is stable (low drift), with a fast response time, adequate selectivities for sweat measurement and very good reversibility. Furthermore, the design of the device avoids sweat contamination, problems related to evaporation, and the passive flow of sweat correctly represents perspiration. Nevertheless, the calibrations of the electrochemical sensors are done before use, in the laboratory. The authors performed control points during the measurement, but by performing an external measurement of the analytes of interest on sweat extracted after sampling.
[0013] An objective of the invention is to propose a device provided with electrochemical sensors, capable of being worn by a person, not having at least one of the aforementioned drawbacks.
[0014] More specifically, an objective of the invention is to propose a device equipped with electrochemical sensors, capable of being worn by a person, the electrochemical sensors being for example capable of carrying out measurements on a biological fluid such as sweat, and at the same time allowing calibration of the electrochemical sensors without sampling intended to carry out an analysis external to the device. Summary of the invention
[0015] To solve the aforementioned objective, the invention proposes a device portable by a person for analyzing a biological fluid, comprising: - an area for collecting a biological fluid such as sweat, - a measuring zone comprising a plurality of electrochemical sensors, - a transport zone for the biological fluid, connecting the collection zone to the measurement zone, the device being characterized in that it comprises: - at least one cartridge filled with a calibration fluid, said at least one cartridge being arranged so that the calibration fluid can reach the measurement zone, and - an evacuation zone for the fluid likely to be present in the measurement zone, said evacuation zone comprising a reservoir zone provided with an absorbent material.
[0016] The invention therefore proposes an innovative solution for improving the precision and reliability of the measurement obtained by electrochemical sensors integrated into a device capable of being worn by a person for the analysis of biological fluids such as sweat.
[0017] As can be understood, the calibration is carried out in situ without any sample being taken from the device for external analysis, of the laboratory type.
[0018] The device according to the invention may comprise at least one of the following characteristics, taken alone or in combination:
[0019] - several cartridges each provided with a calibration fluid, each cartridge being arranged so that the calibration fluid can reach the measuring area,
[0020] - at least two cartridges of said plurality of cartridges comprise a fluid of different calibration;
[0021] - said at least one cartridge or, where appropriate, each cartridge, is mounted on the contact with the transport area via a seal that can be opened under pressure.
[0022] The invention also relates to a method for implementing a device according to one of the preceding claims, characterized in that it comprises the following steps: (a) install the device on a person by placing the collection area against their skin, b) wait until the measuring area is immersed in a sample of biological fluid, for example sweat, (c) carry out a measurement on the biological fluid sample, at the measurement area, (d) evacuate the biological fluid from the measurement area to the fluid evacuation area, (e) exert pressure against the cartridge to release a calibration fluid into the transport area so that it reaches the measurement area, f) waiting for the measuring area to be immersed in the calibration fluid, g) performing a calibration at the measuring area, and h) draining the calibration fluid from the measuring area, wherein either steps a) to h) are carried out consecutively, or steps e), f), g) and h) are first carried out consecutively and then followed by steps a), b), c) and then d).
[0023] The method according to the invention may comprise at least one of the following steps, taken alone or in combination:
[0024] - after having implemented all of steps a) to h), the method comprises the step following: i) repeat steps b), c) and d) N times to carry out a measurement on N other biological sample(s) where N is a natural number greater than or equal to unity;
[0025] - the device comprising several cartridges containing calibration fluids identical, the method comprises, after having implemented step i), the following steps: ef) exerting pressure on another cartridge to release another calibration fluid into the transport zone so that it joins the measurement zone, this other calibration fluid being identical to the calibration fluid used during step e), fi') wait until the measuring area is immersed in the calibration fluid, and gi') perform another calibration at the measuring area.
[0026] - the device comprising several cartridges containing calibration fluids different, the method comprises the following additional steps, implemented directly following step h): ei”) exerting pressure against another cartridge to release another calibration fluid into the transport zone so that it joins the measurement zone, this other calibration fluid being different from the calibration fluid used during step e), fi”) wait until the measurement area is immersed in this other calibration fluid, gi”) carry out a measurement on this other calibration fluid, at the level of the measurement area measure ;
[0027] - after having implemented step gi”), the method comprises the following step: i”) repeat steps b), c) and d) N times to carry out a measurement on N other biological sample(s) where N is a natural number greater than or equal to unity;
[0028] - after the implementation of step i”), the method comprises the following steps: e2') exerting pressure on another cartridge to release another calibration fluid into the transport zone so that it joins the measurement zone, this other calibration fluid being identical to the calibration fluid used during step e), f 2') wait until the measuring area is immersed in the calibration fluid, and g2') perform another calibration at the measuring area;
[0029] - after having evacuated the other calibration fluid from the measurement zone at the end of the implementation of step g2'), the method comprises the following steps: e2”) exert pressure against another cartridge to release yet another calibration fluid in the transport zone so that it reaches the measurement zone, this other calibration fluid being different from the calibration fluid used during step e), f2”) wait until the measurement zone is immersed by this other calibration fluid, g2”) carry out a measurement on this other calibration fluid, at the measurement zone;
[0030] - the calibration fluid used in step e2”) is identical to the calibration fluid employed at step ei”). Brief description of the figures
[0031] Other objects and characteristics of the invention will appear more clearly in the following description, made with reference to the appended figures, in which:
[0032] [Fig. 3] represents a first embodiment of a device portable by a person for analyzing a biological fluid in accordance with the invention;
[0033] [Fig.4] represents a variant of the first embodiment shown in the [Fig.3] ;
[0034] [Fig.5] represents a method of implementing the device of [Fig.3] or [Fig.4], in which a measurement is carried out on the biological fluid and then a calibration;
[0035] [Fig.6] represents another method of implementing the device of [Fig.3] or [Fig.4], in which a calibration is carried out and then a measurement is carried out on the biological fluid;
[0036] [Fig.7] represents a second embodiment of a portable device by a person to analyze a biological fluid in accordance with the invention. Detailed description of the invention
[0037] In [Fig. 3], a first embodiment of a device according to the invention is shown.
[0038] The device D is a device that can be worn by a person to analyze a biological fluid. The device D comprises a collection zone ZC for a biological fluid. The collection zone SC is intended to come into contact with the person's skin and advantageously comprises an adhesive for sticking to the skin. The biological fluid may in particular be the sweat of the person by whom the device D is worn, sweat naturally released during physical activity. The device D also comprises a measurement zone ZM comprising a plurality of electrochemical sensors CEC. The device D also comprises a transport zone ZT for the fluid, connecting the collection zone ZC to the measurement zone ZM.
[0039] The device D further comprises at least one cartridge CART1 filled with a calibration fluid. Said at least one cartridge is arranged so that the fluid calibration fluid can reach the measurement zone ZM. For this purpose, and in this embodiment, the cartridge CART1 is mounted in contact with the transport zone ZT by means of a cover OPC1 which can be opened under the effect of pressure, for example due to the mechanical action of a person on the cartridge or by an automated action (mechanical, thermal, electrical or other) on the cartridge. The transport zone ZT is therefore capable of transporting the sampled biological fluid as the calibration fluid to the measurement zone ZM.
[0040] The device D finally comprises a ZEV evacuation zone for the fluid likely to be present in the measurement zone ZM. This ZEV fluid evacuation zone makes it possible in particular to renew the sample of biological fluid present in the measurement zone to carry out other measurements, or to evacuate the biological fluid to insert a calibration fluid therein or vice versa. Furthermore, the ZEV fluid evacuation zone comprises a reservoir zone ZRES made of an absorbent material, for example a superabsorbent. A superabsorbent is typically made of a porous material with water absorption capacities significantly higher than those of the transport zone ZT (fluidic vein), its size being fixed by the sweat flow and the duration of implementation. This allows the unidirectional transport and then the evacuation of the fluid present in the measurement zone ZM without accumulation of analytes over time.
[0041] In the embodiment variant of [Fig. 4], the device D comprises several cartridges CART1, CART2 each provided with a calibration fluid. In this variant, each cartridge CART1, CART2 is mounted in contact with the transport zone ZT by means of a cover OPC1 which can be opened under the pressing action exerted on the cartridge by a person.
[0042] It can then be provided that the cartridges CART1, CART2 contain an identical calibration fluid. This then makes it possible to carry out several calibrations with the same device D, to adjust or to dispense with the calibration parameter Eo of the electrochemical sensors (see [Fig.2]) several times during the measurements. For example, it is then possible to carry out a calibration before any measurements are taken on a sample of biological fluid and to carry out another calibration after one or a few measurements have been taken on one or more other samples of biological fluid. In particular, it is then possible to carry out a calibration before any measurements have been taken on a sample of biological fluid and to carry out another calibration after having finished said measurements, so that one is then ready to undertake another series of measurements later.
[0043] On the contrary, the cartridges CART1, CART2 can contain a different calibration fluid. This then makes it possible to carry out a calibration with the same device D, to both adjust or overcome the calibration parameter Eo and adjust the sensitivity of electrochemical sensors ([Fig.2]). In particular, it is then possible to carry out such a calibration before taking any measurements on a sample of biological fluid. Of course, and as a variant, this calibration can be carried out between two series of measurements or at the very end of a measurement.
[0044] It will be noted that it is possible to provide many more than two cartridges depending on the needs and furthermore that these cartridges can contain identical or different calibration fluids. In the latter case, the calibration fluids can in particular all be different. Thus, if for example three cartridges are considered, three different calibration fluids can be provided for a better estimation of the sensitivity of the sensors with bodily fluids, which can be particularly complex to analyze.
[0045] As can be seen in Figures 3 (first embodiment) and 4 (variant of the first embodiment), a fluid, whether biological or for calibration, propagates linearly along the device D. From a practical point of view, a person can mount this type of device on their arm, with a bracelet around the wrist for example, the propagation then typically taking place along the axis of the arm.
[0046] Example of embodiment.
[0047] The collection zone ZC may for example be in the form of a collecting pad or a silicone adhesive.
[0048] The transfer zone ZT is for example in the form of a fluidic channel made of a polymer material (it can be made by machining, molding or thermoforming, etc.) or of the paper type.
[0049] The fluid channel portion of the fluid evacuation zone ZEV can be made in a manner analogous to the transfer zone ZT. As for the reservoir zone ZREV of the fluid evacuation zone, a superabsorbent material can be chosen, made of a synthetic material such as sodium polyacrylate, polyacrylonitrile, a non-woven fabric, or paper, or made of a natural material such as cotton or sphagnum.
[0050] Finally, the measuring zone ZM is a fluidic chamber which can be obtained by physical formation of a polymer (machining, thermoforming, molding in particular) or of paper type. Its dimensions and its shape are adapted to the number of measurements required and to their redundancy.
[0051] End of example.
[0052] In [Fig. 5], different steps of a method of implementing a device D according to the invention are shown, such as that shown in [Fig. 3] or in [Fig. 4],
[0053] In the method shown schematically in [Fig.5], a measurement is carried out on the biological fluid and then a calibration is carried out.
[0054] More specifically, the method comprises the following steps: a) install device D on a person by placing the collection area ZC against their skin, b) wait until the measuring area ZM is immersed in a sample of biological fluid, for example sweat, c) carry out a measurement on the biological fluid sample, at the level of the measurement zone ZM, d) evacuate the biological fluid from the ZM measurement zone to the ZEV fluid evacuation zone, e) exert pressure on the CART1 cartridge to release the calibration fluid into the transport zone ZT so that it reaches the measuring zone ZM, f) wait until the measuring area ZM is immersed by the calibration fluid, g) perform a calibration at the measuring area ZM, and h) evacuate the calibration fluid from the measuring area ZM.
[0055] In [Fig.6], different steps of another method of implementing a device D according to the invention are shown, such as that shown in [Fig.3] or in [Fig.4],
[0056] In the process shown schematically in [Fig.6], a calibration is carried out and then a measurement is taken on the biological fluid.
[0057] More specifically, the method comprises the following steps: e) exert pressure on the CART1 cartridge to release the calibration fluid into the transport zone ZT so that it reaches the measuring zone ZM, f) wait until the measuring area ZM is immersed by the calibration fluid, g) perform a calibration at the measuring area ZM, and h) evacuate the calibration fluid from the measuring area ZM, then
[0058] a) installing the device D on a person by placing the collection area ZC against his skin, b) wait until the measuring area ZM is immersed in a sample of biological fluid, for example sweat, c) carry out a measurement on the biological fluid sample, at the level of the measurement zone ZM, d) evacuate the biological fluid from the ZM measurement zone to the ZEV fluid evacuation zone.
[0059] Whatever the implementation variant envisaged, after having implemented all of the steps a) to h) or e) to h) then a) to d), the following step can be implemented: i) repeat steps b), c) and d) N times to carry out a measurement on N other biological sample(s) where N is a natural number greater than or equal to unity.
[0060] In this way, several measurements are carried out with various samples of biological fluid, before calibration (method of [Fig.5]) or after calibration (method of [Fig.6]).
[0061] Furthermore, when the device D comprises several cartridges CART1, CART2 ([Fig.4]) containing identical calibration fluids, the method comprises the following steps, after having implemented step i): ef) exerting pressure on another cartridge CART2 to release another calibration fluid into the transport zone ZT so that it joins the measurement zone ZM, this other calibration fluid being identical to the calibration fluid used during step e), fi') wait until the measuring area ZM is immersed in the calibration fluid, and gi') perform another calibration at the measuring area ZM.
[0062] This makes it possible to implement another calibration of the same type as that which was carried out previously during step g).
[0063] When the device comprises several cartridges CART1, CART2 ([Fig.4]) containing different calibration fluids, the method may comprise the following additional steps, implemented following step h) (namely just after step h) whether a calibration according to step g) has been carried out before or after a measurement on a biological fluid): ei”) exert pressure against another cartridge CART2 to release another calibration fluid into the transport zone ZT so that it joins the measurement zone ZM, this other calibration fluid being different from the calibration fluid used during step e), fi”) wait until the measuring area ZM is immersed in this other calibration fluid, gi”) carry out a measurement on this other calibration fluid, at the level of the ZM measurement zone.
[0064] In this way, a calibration is carried out with at least two different calibration fluids. It is thus possible to make a correction or to dispense with the calibration parameter Eo and to adjust the sensitivity a of the electrochemical sensors.
[0065] After this calibration, other measurements can of course be carried out on other samples of biological fluid. Thus, the method can comprise the following step, after having implemented step gi”): i”) repeat steps b), c) and d) N times to carry out a measurement on N other biological sample(s) where N is a natural number greater than or equal to unity.
[0066] Subsequently, after the implementation of step i”), it is possible to provide another calibration by implementing the following steps: e2') exert pressure on another cartridge CART2 to release another fluid calibration fluid in the transport zone ZT so that it joins the measurement zone ZM, this other calibration fluid being identical to the calibration fluid used during step e), f'2') wait until the measuring area ZM is immersed in the calibration fluid, and g2') perform another calibration at the measuring area ZM.
[0067] Here, it is then only a matter of carrying out a calibration to adjust or free oneself from the calibration parameter Eo and therefore correct a possible drift of the electrochemical sensors in this regard, therefore assuming that the sensitivity a of the electrochemical sensors has not changed.
[0068] On the contrary or in addition, it is however possible to take advantage of this to also correct the sensitivity a of the electrochemical sensors. For this purpose, after having evacuated the other calibration fluid from the measurement zone at the end of the implementation of step g2'), the following steps can be implemented: e2”) exerting pressure against another cartridge CART4 to release yet another calibration fluid into the transport zone ZT so that it joins the measurement zone ZM, this other calibration fluid being different from the calibration fluid used during step e), f2”) wait until the measuring area ZM is immersed by this other calibration fluid, g2”) carry out a measurement on this other calibration fluid, at the level of the ZM measurement zone.
[0069] The calibration fluid used in step e2”) may be identical to the calibration fluid used in step ei”). Another calibration can then be carried out on both the calibration constant and the sensitivity a of the electrochemical sensors.
[0070] On the contrary, in step e2”), the other cartridge CART4 may contain a fluid different from that used in step ei”).
[0071] Generally speaking, a double calibration makes it possible to determine Eo and a. If the double calibration is carried out at a distance in time, it makes it possible to qualify the drift of the sensor. Adding cartridges makes it possible to monitor the drift over the longer term.
[0072] A second embodiment is shown in [Fig.7].
[0073] The same elements are found here as in the first embodiment of the invention, namely a collection zone ZC for a biological fluid ([Fig.7] being a top view, the collection zone below is not visible), a measurement zone ZM equipped with electrochemical sensors CEC, a transfer zone ZT of fluid to the measurement zone ZM, a fluid evacuation zone ZEV (not shown in [Fig.7] to have visibility of the measurement zone ZM, but located above the measurement zone). Furthermore, one or more cartridges CART1, CART2, CART3, CART4 (in this case and as a simple illustrative example, four cartridges in the figure), the or each cartridge containing a calibration fluid, are mounted on the transfer zone ZT, for example by means of a cover OPC1 (shown only for the cartridge CART1), between the collection zone ZC and the measurement zone ZM.
[0074] The originality of this design lies in the conformation of the transfer zone ZT which has a spiral shape, the collection zone ZC and the measurement zone ZM then being located in the central part one above the other. A reservoir zone (belonging to the fluid evacuation zone therefore not visible in [Fig.7]) of the superabsorbent type can be installed above the plane of the figure, against the measurement zone ZM.
[0075] In [Fig.7], it will be noted that the arrow F represents the direction of travel of the fluid within the transfer zone ZT. The arrows F1, F2, F3 and F4 represent the possible actions of a person to press the cartridge concerned and release the calibration fluid that it contains by piercing the OPC1 seal.
[0076] This conformation has the shape of a watch and can therefore be easily worn by a person during physical exertion by means of a circular-shaped receptacle mounted on a bracelet.
[0077] It should be noted that whatever the embodiment considered, the device may integrate a temperature sensor to measure the temperature of the fluid sampled in order to improve the quality of the measurement.
Claims
Claims
1. Device (D) portable by a person for analyzing a biological fluid, comprising: - a collection zone (ZC) for a biological fluid such as sweat, - a measurement zone (ZM) comprising a plurality of electrochemical sensors (CEC), - a transport zone (ZT) for the biological fluid, connecting the collection zone (ZC) to the measurement zone (ZM), the device being characterized in that it comprises: - at least one cartridge (CART1) filled with a calibration fluid, said at least one cartridge being arranged so that the calibration fluid can reach the measurement zone (ZM), and - an evacuation zone (ZEV) for the fluid likely to be present in the measurement zone (ZM), said evacuation zone (ZEV) comprising a reservoir zone (ZRES) provided with an absorbent material.
2. Device (D) portable by a person for analyzing a biological fluid according to the preceding claim, characterized in that it comprises several cartridges (CART1, CART2, CART3, CART4) each provided with a calibration fluid, each cartridge being arranged so that the calibration fluid can reach the measurement zone (ZM).
3. Device (D) portable by a person for analyzing a biological fluid according to the preceding claim, characterized in that at least two cartridges of said plurality of cartridges (CART1, CART2, CART3, CART4) comprise a different calibration fluid.
4. Device (D) portable by a person for analyzing a biological fluid according to one of the preceding claims, characterized in that said at least one cartridge (CART1) or, where appropriate, each cartridge (CART1, CART2, CART3, CART4), is mounted in contact with the transport zone (ZT) by means of a cover (OPC1) which can be opened under the effect of pressure.
5. Method for implementing a device (D) according to one of the preceding claims, characterized in that it comprises the following steps: a) installing the device (D) on a person by placing the collection zone (ZC) against their skin, b) waiting for the measurement zone (ZM) to be immersed in a sample of biological fluid, for example sweat, c) performing a measurement on the biological fluid sample, at the measurement zone (ZM), d) evacuating the biological fluid from the measurement zone (ZM) to the fluid evacuation zone (ZEV), e) exerting pressure against the cartridge (CART1) to release a calibration fluid into the transport zone (ZT) so that it reaches the measurement zone (ZM), f) waiting for the measurement zone (ZM) to be immersed in the calibration fluid, g) performing a calibration at the measurement zone (ZM), and h) evacuating the calibration fluid from the measurement zone (ZM), wherein either steps a) to h) are implemented consecutively, or steps e), f), g) and h) are first implemented consecutively and then followed by steps a), b), c) and then d).
6. Method according to the preceding claim, characterized in that it comprises, after having implemented all of steps a) to h), the following step: i) repeating steps b), c) and d) N times to carry out a measurement on N other biological sample(s) where N is a natural integer greater than or equal to unity.
7. Method according to the preceding claim, characterized in that the device (D) comprising several cartridges (CART1, CART2) containing identical calibration fluids, the method comprises, after having implemented step i), the following steps: ei') exerting pressure on another cartridge (CART2) to release another calibration fluid into the transport zone (ZT) so that it joins the measurement zone (ZM), this other calibration fluid being identical to the calibration fluid used during step e), fi') waiting for the measurement zone (ZM) to be immersed in the calibration fluid, and gi') carrying out another calibration at the measurement zone (ZM).
8. Method according to claim 5, characterized in that, the device (D) comprising several cartridges (CART1, CART3) containing different calibration fluids, the method comprises the following additional steps, implemented directly following step h): ei”) exerting pressure against another cartridge (CART3) to release another calibration fluid into the transport zone (ZT) in order that it joins the measurement zone (ZM), this other calibration fluid being different from the calibration fluid used during step e), fi”) wait until the measurement zone (ZM) is immersed in this other calibration fluid, gi”) carry out a measurement on this other calibration fluid, at the measurement zone (ZM).
9. Method according to the preceding claim, characterized in that it comprises, after having implemented step gi”), the following step: i”) repeating steps b), c) and d) N times to carry out a measurement on N other biological sample(s) where N is a natural integer greater than or equal to unity.
10. Method according to the preceding claim, characterized in that it comprises, after the implementation of step i”), the following steps: e2') exerting pressure on another cartridge (CART2) to release another calibration fluid into the transport zone (ZT) so that it joins the measurement zone (ZM), this other calibration fluid being identical to the calibration fluid used during step e), f'2') waiting for the measurement zone (ZM) to be immersed in the calibration fluid, and g2') carrying out another calibration at the measurement zone (ZM).
11. Method according to the preceding claim, characterized in that it comprises, after having evacuated the other calibration fluid from the measurement zone at the end of the implementation of step g2'), the following steps: e2”) exerting pressure against another cartridge (CART4) to release yet another calibration fluid into the transport zone (ZT) so that it joins the measurement zone (ZM), this other calibration fluid being different from the calibration fluid used during step e), f2”) waiting for the measurement zone (ZM) to be immersed by this other calibration fluid, g2”) carrying out a measurement on this other calibration fluid, at the measurement zone (ZM).
12. Method according to the preceding claim, characterized in that the calibration fluid used in step e2”) is identical to the calibration fluid used in step ei”).