FAULT INDICATOR FOR A WEARABLE DEVICE

Description

FIELD OF INVENTION

[0001] The present invention relates to a system for measuring electromagnetic or electrostatic disturbances intended to be worn by a user. The present invention also relates to a garment comprising such a system. STATE OF THE ART

[0002] Smart clothing designed to measure bioelectrical signals requires the transmission of very low electrical signals (on the order of a few microvolts to a few millivolts) via electrical connections of considerable length, driven by high contact impedances. These signals are therefore subject to a significant risk of electromagnetic or electrostatic interference. This interference can be varied. It can be caused by high-frequency radio waves, electrostatic or low-frequency disturbances, for example, if another person passes near the sensors. The mains voltage can also generate noise at 50 Hz or 60 Hz on the measured and transmitted signals.

[0003] These disturbances hinder the processing and interpretation of signals, whether performed manually by technicians or physicians, or digitally by algorithms. In the medical field, a physician's expertise can help distinguish between different types of artifacts, but only to a very limited extent. These electromagnetic or electrostatic disturbances can even lead to a distorted diagnosis or result in an inconclusive one.

[0004] US patent 2009 / 318827 describes a system and method for monitoring the electrical activity of a subject's brain by means of a plurality of electrodes placed near a portion of the subject's body. The system further includes an antenna.

[0005] The antenna in US document 2009 / 318827 is capable of emitting signals but is not suitable for measuring electromagnetic signals.

[0006] John et al. describe a system comprising a vascular implant, a pressure sensor, and a wireless transmission antenna for data recorded by the sensor to an external analysis unit (Biomedical Engineering, 2016, pp. 155-159). The described antenna is capable of transmitting signals but is not suitable for measuring electromagnetic signals.

[0007] Kang et al. describe a system for acquiring physiological signals comprising a circuit with several conductive tracks and electronic elements designed to reduce the output impedance of an electrode connected to said circuit. The conductive tracks are not suitable for measuring electromagnetic signals.

[0008] Document EP 2 407 096 describes a textile electrode for measuring body signals, in which a conductive track is used to simplify the connection between the electrode and the acquisition system. The described conductive track is not suitable for measuring electromagnetic signals.

[0009] The object of the present invention is therefore to provide a system for measuring electromagnetic or electrostatic disturbances, intended to be worn by a user and integrated into clothing. The present invention thus makes it possible to determine whether measurements taken on smart clothing are altered by external electromagnetic or electrostatic disturbances. SUMMARY

[0010] The present invention relates to a disturbance measurement system intended to be worn by a user. Said system comprises at least one bioelectrical measuring means; an analog-to-digital converter electrically connected to said at least one bioelectrical measuring means; and at least one conductive track electrically connected to a ground of the system via a resistor and to an input of the analog-to-digital converter.

[0011] In one embodiment of the invention, the length of said at least one conductive track is greater than 1 cm. In another embodiment of the invention, the length of said at least one conductive track is greater than 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm or 20 cm, 30 cm, 40 cm or 50 cm.

[0012] In one embodiment of the invention, the electrical signal measured by at least one conductive track is subtracted from the electrical signal measured by at least one bioelectrical measuring means to produce a purified resulting signal.

[0013] In one embodiment of the invention, a resistor coupled to the conductive track simulates a contact impedance between the skin and at least one bioelectrical measuring means.

[0014] In one embodiment of the invention, the impedance of said resistor is between 10 kΩ and 100 MΩ. In another embodiment of the invention, the system further comprises a capacitor connected in parallel with said resistor. In another embodiment of the invention, the capacitance of said capacitor is between 10 picofarads and 100 nanofarads.

[0015] In one embodiment of the invention, at least one conductive track comprises a first end electrically connected to the system ground and to an input of the analog-to-digital converter, and a second free end.

[0016] The system further comprises a textile substrate in which the biometric measurement means and at least one conductive track are mechanically connected to said textile substrate. In one embodiment of the invention, the substrate is a textile substrate and the at least one conductive track: includes at least one conductive thread woven, embroidered, knitted or inserted through the textile substrate; or is conductive ink or conductive paint printed on the textile substrate.

[0017] The invention also relates to a garment comprising at least one disturbance measurement system according to the present invention.

[0018] The invention also relates to a method of using the disturbance measurement system according to the present invention or the garment according to the present invention, comprising the following steps: the measurement of the signal obtained by at least one bioelectrical measuring means; the measurement of the signal obtained by at least one conductive track; and the processing of said signals so as to remove, from the signal measured by at least one bioelectrical measuring means, the signal measured by at least one conductive track. DEFINITIONS

[0019] In the present invention, the terms below are defined as follows: By " Garment "This refers to any textile suitable for wear by a person, including a hat. By " Loop antenna "We are referring to an antenna that measures the magnetic field of its environment. Its operating principle is based on the application of Lenz's law, whereby the induced voltage is proportional to the magnetic field flux. By " Device intended to be worn by a user "We mean any garment, clothing, hat, or undergarment suitable for wear by a user, preferably in contact with the skin. By " Bioelectrical measurement method "We mean any sensor capable of measuring an electrical signal produced by a living organism, whether in contact with or at a distance from the skin. By " Analog-to-digital conversion device "We mean an electronic device that transforms an electrical signal into digital data. By " Leading track"We mean a conductive zone. This conductive track may consist of one or more conductive wires, said conductive wires being made of a conductive material or textile yarns covered with a conductive surface or a conductive material, preferably textile yarns covered with conductive metals such as silver. This conductive track may also consist of a conductive ink or a conductive paint on a substrate, the conductive ink or paint being loaded with an electrically conductive material, possessing flexible properties, allowing this conductive ink or paint to be deposited on flexible surfaces. By " End"The end of the outermost part is understood to mean the longest dimension of the conductive track. In the case where the conductive track is a surface, the end is constituted by the extension(s) intended to be connected to a ground of the system and / or to an input of an analog-to-digital conversion device. By " Substrate "We mean a part serving as a support for at least one or all of the components of the system according to the present invention, By " Textile substrate "We mean a substrate made of insulating textile yarns that can be woven or knitted. By " Mechanical substrate "We mean a substrate consisting of at least one rigid piece, or a piece that is not a textile. By " Flexible ", we mean the ability to be bent on a cylindrical part with a radius of 5 to 10 cm without undergoing plastic deformation. When a range of values ​​is evoked by the expression " between A and B"A" means that the two values ​​mentioned, "A" and "B", are included within the specified range of values. Also included are all values ​​within ±10% of the range's limits. DETAILED DESCRIPTION

[0020] As illustrated on the figure 1 , The present invention relates to a disturbance measurement system 1 intended to be worn by a user. This system 1 comprises at least one bioelectric measuring means 4; an analog-to-digital converter 6 electrically connected to said at least one bioelectric measuring means 4; and at least one conductive track 2 electrically connected to ground 7 of the system 1 via a resistor 8 and to an input 61 of the analog-to-digital converter 6.

[0021] The invention relates to a disturbance measurement system (1) intended to be worn by a user, said system comprising: at least one bioelectric measuring means (4) for measuring a bodily electrical signal and capable of receiving external electromagnetic and / or electrostatic disturbances; an analog-to-digital converter (6) electrically connected to said at least one bioelectric measuring means (4); and at least one conductive track (2) for measuring electromagnetic and / or electrostatic signals, said conductive track (2) being electrically connected to a ground (7) of the system (1) via a resistor (8) and to an input (61) of the analog-to-digital converter (6).

[0022] At least one bioelectrical measuring means 4 enables the measurement of electrical signals emitted by the human or animal body. In one embodiment, this means is a metallic or conductive electrode in contact with the skin capable of measuring very small variations in electrical signals, such as those measured by electroencephalography (EEG), electrocardiography (ECG), or electromyography (EMG). In another embodiment, the measuring means may also be an electrooculogram (EOG) sensor or a means for detecting light stimuli.

[0023] According to the present invention, at least one bioelectric measuring means 4 is electrically connected to the analog-to-digital conversion device 6 by an electrical connection 3. Said analog-to-digital conversion device 6 is capable of converting into a digital quantity the electrical signal from at least one bioelectric measuring means 4.

[0024] The conductive track 2 according to the present invention acts as an antenna. It must therefore extend over a sufficient length or surface area to detect electromagnetic and / or electrostatic disturbances that are also recorded by at least one bioelectrical measuring means 4 and that interfere with the measured signal. The length or surface area of ​​this conductive track 2 must therefore be sufficiently large, and its purpose extends beyond a simple electrical connection between two components.

[0025] The conductive track 2 is electrically connected to ground 7 of system 1 and to an input 61 of the analog-to-digital converter 6. In this way, the analog-to-digital converter 6 is able to convert the electrical signal from the conductive track 2 into a digital quantity.

[0026] In one embodiment, the conducting track 2 is a conducting path in which two dimensions have a negligible distance compared to the distance of the third dimension.

[0027] In an embodiment illustrated on the figure 1 , The conductive track 2 is electrically connected to ground 7 of system 1 by one end and is electrically connected to an input 61 of the analog-to-digital converter 6 by a second end. In one embodiment, the conductive track 2 comprises a first end electrically connected to ground 7 of system 1 and a second end electrically connected to an input 61 of the analog-to-digital converter 6.

[0028] In an alternative illustrated embodiment figure 2 ,The conductive track 2 comprises at least two ends. The first end is electrically connected to ground 7 of system 1 and to an input 61 of the analog-to-digital converter 6, and the second end is free. In this embodiment, the conductive track comprises a first end electrically connected to ground 7 of system 1 and to an input 61 of the analog-to-digital converter 6, and a second free end. "The second end is free" means that this end is not connected to any resistor or electrically conductive element, so as to create an open circuit. In one embodiment, the first end is connected to an input of a printed circuit board, and said input of the printed circuit board is electrically connected to ground of system 7 and to an input 61 of the analog-to-digital converter 6.

[0029] In an embodiment not shown, the conductive track 2 comprises a plurality of free ends.

[0030] The conductive track 2 must be long enough to allow for the measurement of disturbances. The conductive track 2 has a length greater than 1 cm, 2 cm, 3 cm, 4 cm, 5 cm, 6 cm, 7 cm, 8 cm, 9 cm, 10 cm, 20 cm, 30 cm, 40 cm, or 50 cm. The conductive track 2 has a length between 5 cm and 500 cm, or between 5 cm and 200 cm. In one embodiment, the conductive track 2 has a length between 5 cm and 100 cm. In one embodiment, the maximum length of the conductive track 2 is not limited.

[0031] This length allows for better accuracy in measuring disturbances, for example electromagnetic or electrostatic disturbances that do not originate from the body of the user wearing system 1 according to the present invention.

[0032] Indeed, the conductive track 2 must have sufficient length to record the disturbances.

[0033] In an alternative embodiment not shown, the antenna function is performed by a surface surrounded by a conductive track 2 electrically connected to the analog-to-digital converter 6 and to a ground of the system 7. The conductive track 2 must then surround a sufficiently large area to allow the measurement of disturbances. In this embodiment, the area surrounded by the conductive track 2 is greater than 1 cm². In another embodiment, the area surrounded by the conductive track 2 is greater than 10, 20, 30, 40, 50, 100, 200, or 300 cm².

[0034] In one embodiment, the conductive track 2 extends over a textile or mechanical substrate 5.

[0035] In an embodiment where the substrate 5 is a textile substrate, the conductive track 2 is made to have the same flexibility as the textile substrate 5. The conductive track 2 must be able to be bent upon itself without undergoing plastic deformation and without suffering damage that could lead to a break in the electrical connection. In one embodiment, the conductive track 2 has sufficient flexibility to be bent over a cylindrical part having a radius of 5 to 10 cm without undergoing plastic deformation.

[0036] In one embodiment, the conductive track 2 forms a loop antenna. In this same embodiment, the shape traced by the conductive track 2 can be an oval, circular, rectangular, triangular, ellipsoidal, or any other shape.

[0037] In one embodiment, the bioelectric measuring means 4 can be located inside the shape traced by the conductive track 2. In another embodiment, the bioelectric measuring means 4 can be located substantially at the center of the shape traced by the conductive track 2. Placing the bioelectric measuring means 4 inside the shape traced by the conductive track 2 allows for a better indication of the electromagnetic and / or electrostatic disturbances measured by at least one bioelectric measuring means 4, since these disturbances will be measured as close as possible to at least one bioelectric measuring means 4.

[0038] In one embodiment, the electrical signal measured by at least one conductive track (2) is subtracted from the electrical signal measured by at least one bioelectrical measuring means (4) to produce a purified resulting signal.

[0039] According to the present invention, the analog-to-digital conversion device 6 is capable of converting into a digital quantity the electrical signal from the conductive track 2 and the electrical signal from at least one bioelectric measuring means 4.

[0040] The numerical values ​​from the conductive track 2 correspond to electromagnetic and / or electrostatic disturbances also recorded by at least one bioelectric measuring means 4. By subtracting the values ​​from the conductive track 2 from the values ​​from at least one bioelectric measuring means 4, we obtain the values ​​of a signal purified of parasitic external signals.

[0041] In one particular embodiment, the system 1 also includes a means (such as an electronic device or an algorithm) for subtracting values ​​from the conductive track from the values ​​obtained from at least one bioelectrical measuring means 4. In another embodiment, this operation can be performed after the fact, or more simply, the person responsible for interpreting the measurements can compare the two values ​​to facilitate their interpretation of the values ​​obtained from at least one bioelectrical measuring means 4.

[0042] In an embodiment not shown, the system 1 also includes a printed circuit board and the analog-to-digital conversion device 6 is integrated on this printed circuit board.

[0043] According to the present invention, at least one conductive track 2 is electrically connected to the ground of the system 7 via a resistor 8. This resistor 8 allows the measurement of the electrical signal from the conductive track 2. Low frequencies could not be measured without a resistor.

[0044] In one embodiment, the impedance of the resistor 8 must be of the same order of magnitude, and preferably as close as possible to the contact impedance between the skin and at least one bioelectrical measuring means 4. Thus, the electrical signals measured by the conductive track 2 can be compared to the signals measured by at least one bioelectrical measuring means 4.

[0045] In one embodiment, the conductive track (2) is configured to receive signals such as electromagnetic and / or electrostatic signals.

[0046] In one embodiment, the conductive track (2) is not configured to emit signals such as electromagnetic and / or electrostatic signals.

[0047] In one embodiment, the resistance coupled to the conductive track (2) simulates a contact impedance between the skin and at least one bioelectrical measuring means (4).

[0048] In an embodiment where at least one bioelectrical measurement means 4 is a dry EEG electrode, the order of magnitude of the contact impedance between the user's skin and the dry EEG electrode is between 100 kOhms and 10 MOhms (10 Megaohms).

[0049] In one embodiment, the impedance of said resistor 8 is between 10 kOhms and 100 MOhms. In a preferred embodiment, the impedance of said resistor 8 is between 100 kOhms and 10 MOhms, preferably between 500 kOhms and 5 MOhms, most preferably between 700 kOhms and 2 MOhms, and even more preferably between 800 kOhms and 1.5 MOhms.

[0050] In an embodiment illustrated on the figure 1 and the figure 2 , Resistor 8 is part of the analog-to-digital converter 6. In another, illustrated embodiment figure 5 ,The resistor 8 is not integrated into the analog-to-digital conversion device 6 but is fixed to the substrate 5, in contact with the conductive track 2. In an embodiment not shown, the resistor is not fixed to the analog-to-digital conversion device 6 but is integrated on a printed circuit board comprising the analog-to-digital conversion device 6.

[0051] In an illustrated embodiment Figure 3 and Figure 4 ,To approximate the contact impedance between the skin and at least one bioelectrical measuring device, system 1 includes a capacitor 9 connected in parallel with the resistor 8. This capacitor 9 models the parasitic capacitance between the skin and at least one bioelectrical measuring device 4. The capacitance of capacitor 9 must be of the same order of magnitude, and preferably as close as possible, to the parasitic capacitance of the contact between the skin and at least one bioelectrical measuring device 4. Thus, the electrical signals measured by the conductive track 2 can be compared to the signals measured by at least one bioelectrical measuring device 4. The order of magnitude of the capacitance of said capacitor 9 varies depending on the bioelectrical measuring device 4 used. In one embodiment, said capacitor 9 has a capacitance between 10 picofarads and 100 nanofarads.

[0052] In another illustrated embodiment figure 5 , Resistor 8 and capacitor 9 are not integrated into the analog-to-digital converter 6 but are fixed to the substrate 5, in contact with the conductive track 2. In an embodiment not shown, resistor 8 and capacitor 9 are not integrated into the analog-to-digital converter 6 but are integrated on a printed circuit board comprising the analog-to-digital converter 6.

[0053] System 1 comprises a textile substrate 5 on which are mounted the bioelectric measuring means 4, the analog-to-digital converter 6, and the conductive track 2. System 1 comprises a textile substrate 5, and said biometric measuring means 4 and said conductive track 2 are mechanically connected to said textile substrate 5. This substrate 5 ensures the cohesion of the various components of system 1. In one embodiment, the analog-to-digital converter is also mechanically connected to the substrate 5.

[0054] In an alternative, unclaimed embodiment, the substrate 5 is a mechanical substrate. The mechanical substrate 5 may consist of a plate of plastic material, or more generally, any support comprising an insulating contact surface with the conductive track 2. In one embodiment, the mechanical substrate 5 is a mechanical armature that can be used for manufacturing a helmet. The mechanical substrate 5 may be rigid or flexible.

[0055] Substrate 5 is a textile substrate. In one embodiment, textile substrate 5 is a woven or knitted textile with insulating yarns.

[0056] The substrate 5 is a textile substrate. The use of a textile substrate gives the system 1 its flexibility and elasticity properties. In this same embodiment, the conductive track 2 is made to have substantially the same flexibility as the textile substrate 5. In an embodiment where the substrate 5 is a textile substrate, the conductive track 2 comprises at least one conductive thread woven, embroidered, knitted, or inserted through the textile substrate 5. In this same embodiment, the at least one conductive thread is made of a conductive material or at least one textile thread coated with a conductive surface, preferably coated with a conductive metal such as silver. In an alternative embodiment, the conductive track 2 is a conductive ink or a conductive paint printed onto the textile substrate 5.

[0057] In one embodiment, the conductive track 2 is delimited by its ends. In another embodiment, the conductive track 2 is delimited by its junction with the analog-to-digital converter 6. In yet another embodiment, the conductive track 2 is delimited by its junction with the resistor, the input 61 of the analog-to-digital converter 6, and optionally the capacitor 9. In one embodiment, the conductive track 2 is delimited by the point of connection with the printed circuit board.

[0058] In one embodiment, system 1 comprises several conductive tracks 2.

[0059] Ground 7 is the reference branch for electrical potentials. Ground 7 can be located on the analog-to-digital conversion device 6 or elsewhere on the system 1 according to the present invention, for example on the substrate 5.

[0060] The invention also relates to a garment comprising at least one disturbance measurement system 1 according to the present invention. The term "garment" refers to any textile suitable for wear by a subject, including a hat. In a preferred embodiment, said garment is intended to be worn in contact with the skin, so as to facilitate the reliability of the measurement recorded by the at least one bioelectrical measurement device 4, such as underwear, a hat, a jersey, or a T-shirt.

[0061] In one embodiment, the invention is applied to an already existing measuring device such as an EEG headset or other.

[0062] In one embodiment, the garment is a cap comprising two systems 1 according to the present invention. In this embodiment, the two systems 1 according to the present invention are arranged on either side of the cap. The user can therefore position one system 1 in contact with the left side of their head and one system 1 in contact with the right side of their head.

[0063] According to one embodiment, the garment according to the present invention allows the measurement of external electromagnetic and / or electrostatic disturbances to which at least one bioelectric measuring means 4 is exposed.

[0064] The invention also relates to a method of using the disturbance measurement system 1 according to the present invention, comprising the following steps: the measurement of the signal obtained by at least one bioelectrical measuring means 4; the measurement of the signal obtained by at least one conductive track 2; and the processing of said signals so as to remove, from the signal measured by at least one bioelectrical measuring means, the signal measured by at least one conductive track 2.

[0065] The processing stage of said signals can be carried out by an algorithm, an electronic module, a data processing system or by a technician. BRIEF DESCRIPTION OF THE FIGURES

[0066] There Figure 1 is a schematic view of system 1 according to an embodiment of the present invention in which the conductive track 2 forms a loop antenna. The conductive track 2 comprises two ends; a first end is connected to the input 61 of the analog-to-digital converter 6, and a second end is connected to ground 7 of system 1. Figure 2is a schematic view of system 1 according to an embodiment of the present invention in which the conductive track 2 does not form a closed circuit. The conductive track 2 comprises a first end connected to the input 61 of the analog-to-digital converter 6 and connected to ground 7 of system 1. The conductive track 2 comprises a second end which is not connected to any resistor or any electrically conductive element, so as to create an open circuit. Figure 3 is a schematic view of system 1 according to an embodiment of the present invention according to the Figure 1 in which a capacitor 9 is connected in parallel with the resistor 8. Figure 4 is a schematic view of system 1 according to an embodiment of the present invention according to the Figure 2 in which a capacitor 9 is connected in parallel with the resistor 8. Figure 5is a schematic view of system 1 according to an embodiment of the present invention according to the Figure 4 in which the resistor 8 and the capacitor 9 are mounted on the textile or mechanical substrate 5 and not on the analog-to-digital converter 6. The figures are provided for educational purposes only, to enable the reader of this patent application to better understand the invention. The figures are therefore not to scale, and the scope of this patent application should not be limited by the distances shown in the figures. REFERENCES

[0067] 1 - Disturbance measurement system; 2 - Conductive track; 3 - Electrical connection means; 4 - Bioelectric measurement means; 5 - Substrate; 6 - Analog-to-digital conversion device; 61 - Input of the analog-to-digital conversion device; 7 - System ground; 8 - Resistor; 9 - Capacitor.

Claims

1. Disturbance measurement system (1) capable of being incorporated in a garment intended to be worn by a user, said system comprising: - at least one bioelectrical measurement means (4) for measuring a body electrical signal and likely of receiving external electromagnetic and / or electrostatic disturbances; - an analogue-to-digital conversion device (6) electrically connected to said at least one bioelectrical measurement means (4); and - at least one conductive track (2) for measuring electromagnetic and / or electrostatic signals, said conductive track (2) being electrically connected to a ground (7) of the system (1) via a resistor (8) and to an input (61) of the analogue-to-digital conversion device (6), said conductive track (2) having a length between 5 cm and 500 cm to enable the measurement of external electromagnetic and / or electrostatic disturbances likely to disturb the measured signal; and - a textile substrate (5), wherein said biometric measurement means (4) and said at least one conductive track (2) are mechanically connected to said textile substrate (5).

2. System (1) according to claim 1, characterised in that it is configured so that the electrical signal measured by the at least one conductive track (2) is subtracted from the electrical signal measured by the at least one bioelectrical measurement means (4) to produce a resulting signal purified from the parasitic external signals.

3. System (1) according to claim 1 or claim 2, characterised in that it is configured for a resistor coupled to the conductive track (2) to simulate a contact impedance between the skin and at least one bioelectric measurement means (4).

4. System (1) according to any one of claims 1 to 3, wherein the impedance of said resistor (8) is between 10 kOhms and 100 MOhms.

5. System (1) according to any one of claims 1 to 4, further comprising a capacitor (9) connected in parallel to said resistor (8).

6. System (1) according to claim 5, wherein the capacitance of said capacitor (9) is between 10 picofarad and 100 nanofarad.

7. System (1) according to any one of claims 1 to 6, wherein the at least one conductive track (2) comprises a first end electrically connected to the ground (7) of the system (1) and to an input (61) of the analogue-to-digital conversion device (6), and a free second end.

8. System (1) according to any one of claims 1 to 6, wherein the at least one conductive track (2) comprises a first end electrically connected to the ground (7) of the system (1) and a second end electrically connected to an input (61) of the analogue-to-digital conversion device (6).

9. System (1) according to claim 8, wherein the substrate (5) is a textile substrate (5) and the at least one conductive track (2): - comprises at least one conductive yarn woven, embroidered, knitted or inserted through the textile substrate (5); or - is a conductive ink or conductive paint printed on the textile substrate (5).

10. Garment comprising at least one disturbance measurement system (1) according to any one of claims 1 to 9.

11. Method for using the disturbance measurement system (1) according to any one of claims 1 to 9 or for using the garment according to claim 11, comprising the following steps: - measuring the body signal obtained by the at least one bioelectric measurement means (4); - measuring the signal of electromagnetic and / or electrostatic disturbances, obtained by the at least one conductive track (2); and - processing said signals so as to remove, from the signal measured by the at least one bioelectric measurement means, the signal measured by the at least one conductive track (2).