Method for measuring the variation in inductance of a magnetic coil created by an inductive elongation sensor wire and use of a device comprising at least one elastic textile part equipped with an inductive elongation sensor wire

Abstract

The present invention relates to a device comprising at least one textile part that is elastic in at least one first direction, the textile part comprising an inductive elongation sensor wire (120) comprising an elastic core wire (125) and an electrically conductive covering wire (130) forming turns (135) around said elastic core wire (125), and the electrically conductive covering wire (130) comprises a filament or a plurality of filaments, each of the or said filaments comprises an electrically conductive core covered with an electrically nonconductive sheath. The present invention also relates to the use of such a device for measuring the variation in the inductance of the magnetic coil created by said inductive elongation sensor wire (120) when the elastic textile part is extended in the first direction, and to an associated measurement method.

Description

Technical Field

[0001] The present invention relates to devices, in particular medical and / or sports devices, comprising at least one textile piece elastic in at least a first direction, said textile piece comprising at least one inductive elongation sensor thread.

[0002] The present invention also relates to the use of such a device and a measuring method implementing said device. Prior art

[0003] Medical devices with elastic areas, such as lumbar support belts, orthoses, or compression stockings, must be correctly placed on the part of the body to be treated so that the patient can correctly comply with the treatment.

[0004] There is therefore a need to evaluate the behavior, in particular elastic and / or deformation, of a medical device comprising an elastic textile part when worn in order to improve the performance of the medical device, and its compliance by the patient.

[0005] Electrically conductive threads can be used in a textile piece to capture and transmit information collected about the wearer.

[0006] However, the implementation of an electrically conductive thread in a textile piece presents numerous constraints since, by definition, a conductive thread, not being elastic, stiffens the textile piece, modifies its appearance and feel, and can create allergic reactions if it comes into contact with the skin.

[0007] The implementation of a conductive thread in an elastic textile piece further complicates its implementation, since the conductive thread must not be broken or its electrical conductivity properties degraded during the elongation of the textile piece.

[0008] FR 2.869.047 B1 relates to a woven textile piece comprising an electrically conductive and elastic composite yarn used as a deformation sensor. The composite yarn comprises a low-count elastic core, 44 dtex, covered by wrapping with a conductive yarn having a polyamide core coated with silver, having a count of around 33 to 44 dtex. This composite yarn can only be used in woven textile pieces and is not suitable for knitted textile pieces for which the deformation of the loops would disturb the measurement of the variation in electrical conductivity. The variation in electrical conductivity measured in the fabric during its deformation would make it possible to evaluate a certain degree of elongation. The deformations studied are respiratory movements or uterine contractions.The turns are joined together to conduct electricity from one turn to the next, their variable spacing resulting in a variation in conductivity, the turns however remaining in contact with each other to conduct electricity from one turn to the next in a stretched or at rest state. In addition, the crossing of the conductive threads, arranged both in warp and weft in the fabric, risks causing short circuits.

[0009] CA 2.493.145 relates to an electrically conductive and elastic thread comprising an elastic core thread and at least one electrically conductive thread wound around the elastic core thread. The number of turns of the conductive thread and the binding thread around the elastic core thread must be sufficient, of the order of 3200-3600 turns / m, so that the electricity is conducted by contact from one turn to the other and the electrical conductivity does not decrease due to over-elongation of the conductive thread. The number of turns per meter of the conductive thread and the binding thread are very large, which limits the elasticity properties of the elastic core thread. These conductive threads are used for the manufacture of heated textiles and not for measuring the elongation of the latter.

[0010] WO 2006 / 034291 A2 relates to a sensor for monitoring respiratory plethysmography by inductance. This type of sensor comprises an elastic textile encircling the wearer's thorax, and a conductor sewn in a zigzag pattern flat on the surface of the textile. The conductor does not form turns around a core thread, in particular an elastic one, but portions encircling the wearer's thorax. The circumference of these portions varies according to the elongation of the textile as a function of respiratory movements.

[0011] Documents WO 2004 / 097089 A1 and WO 2018 / 037855 A1 describe a yarn comprising an elastic core yarn and an electrically conductive cover yarn forming turns around said elastic core yarn, the electrically conductive cover yarn comprises one or more filaments, each of said filament(s) comprises an electrically conductive core covered with an electrically non-conductive sheath.

[0012] There is therefore a need for a device, in particular medical and / or for the practice of a sport, comprising an elastic textile part, said device is configured to allow the evaluation of the elastic behavior of the textile part, and therefore its behavior when worn, without altering the essential elastic properties sought for the textile part. There is also a need for a device, medical and / or for the practice of sport, not comprising, when worn, and in particular at rest, areas conducting electricity likely to come into contact with the wearer's skin. Subject matter and summary of the invention

[0013] The present invention aims to propose a device comprising an elastic textile piece comprising at least one inductive elongation sensor wire in order to evaluate the elongation of the textile piece, in particular in the direction of insertion of said sensor wire into the textile piece, by measuring the variation in the inductance (µHenry) of the coil created by this sensor wire.

[0014] The present invention also aims to provide a device for exchanging signals and / or transferring electrical energy via said inductive elongation sensor wire.

[0015] The present invention relates to a device, in particular medical and / or for practicing a sport, comprising at least one textile piece elastic in at least a first direction, the textile piece comprising at least one inductive elongation sensor thread, said inductive elongation sensor thread comprising an elastic core thread and an electrically conductive cover thread forming turns around said elastic core thread, the electrically conductive cover thread comprising one filament or several filaments, each of said filament(s) comprises an electrically conductive core covered with an electrically non-conductive sheath.

[0016] Advantageously, the electrically conductive covering wire thus forms a coil capable of generating a magnetic field under the effect of a current (A) passing through the electrically conductive covering wire. The inductance of the coil varies, in particular increases, when the elastic core wire elongates and the turns move away from each other.

[0017] Since inductance (and not electrical conductivity) is measured for the evaluation of elasticity, it is not necessary (which is not possible due in particular to the electrically insulating sheath and the non-contiguous arrangement of the turns) for the turns to conduct electricity by contact from one turn to the other, which makes it possible in particular to limit the number of turns or revolutions / m and thus preserve the elastic and touch properties of the elastic textile part.

[0018] Furthermore, it is not intended that the conductive covering yarn should release heat so that the number of turns, and therefore the linear quantity of conductive covering yarn in the textile piece, is large for the heat released to be significant.

[0019] The electrically non-conductive (or electrically insulating) sheath advantageously prevents short circuits in the event of possible contact between the coils, and prevents contact with the skin of the conductive part (which is mandatory for a medical device).

[0020] In addition, said sheath improves the resistance to washing and abrasion of the conductive core.

[0021] Inductance values are measured in micro Henry (µH).

[0022] The medical device may comprise one or more elastic textile pieces according to the invention, assembled for example by sewing or welding, in particular chosen from elastic knitted textile pieces and / or elastic woven textile pieces.

[0023] The medical device may also comprise one or more textile pieces, elastic or not, assembled with one or more elastic textile pieces according to the invention (i.e. each comprising at least one inductive elongation sensor thread).

[0024] Any textile piece in this text, whether elastic or not, has a longitudinal direction, in particular corresponding to the direction of the columns of stitches when the textile piece is a knitted piece, or to the warp direction when the textile piece is a woven piece; and a transverse direction, in particular corresponding to the direction of the rows of stitches (also called weft in the technical field) when the textile piece is a knitted piece, or to the weft direction when the textile piece is a woven piece.

[0025] Preferably, the longitudinal direction is substantially perpendicular to the transverse direction. Said first direction may be said longitudinal direction, or the transverse direction, or a direction intersecting the longitudinal and transverse directions.

[0026] Preferably, said at least one inductive elongation sensor wire is arranged in the elastic textile piece in the first direction.

[0027] Said textile piece may also be elastic in a second direction, different from the first direction. The second direction may then be said longitudinal direction, or the transverse direction, or a direction intersecting the longitudinal and transverse directions. A second inductive elongation sensor wire (identical or different from the first sensor wire) may be arranged in said second direction.

[0028] In some embodiments, an inductive elongation sensor yarn may extend in both the longitudinal and transverse directions. For example, when the inductive elongation sensor yarn extends diagonally (corresponding to said first direction) of the elastic textile piece (in a direction intersecting, not at right angles, the longitudinal and transverse directions), for example in the form of weft throws over several columns of stitches on a warp-knitted textile piece.

[0029] By elastic textile part in at least one first (and / or second) direction(s) is meant any elastic textile part capable of elongating by at least 100%, more preferably by at least 200%, in particular by at most 400%, in particular by at most 300%, in said at least one first (and / or second) direction(s), under the effect of a given force (less than the breaking force), with a recovery of its initial shape, returned to rest and stabilized, at plus or minus 5%. These values can be determined for example using the NF EN ISO 2062 standard of January 2010.

[0030] The inductive elongation sensor wire is elastic. Preferably, the inductive elongation sensor wire has an elongation at break greater than or equal to 100%, preferably greater than or equal to 150%, in particular less than or equal to 350%, more particularly less than or equal to 250%. These values can be determined for example using the NF EN ISO 2062 standard of January 2010.

[0031] Preferably, the electrically conductive core is made of an electrically conductive metal or an alloy of electrically conductive metals.

[0032] Preferably, the electrically conductive metal or the alloy of electrically conductive metals is chosen from: copper, silver, steel or a mixture thereof.

[0033] Preferably, the sheath is in a mixture of one or more electrically non-conductive polymer(s), preferably chosen from: polyurethane, polyamide, polyester (polyethylene terephthalate), polyethylene, polypropylene, silicone, or a mixture thereof.

[0034] Preferably, the sheath is an electrically insulating varnish.

[0035] Said at least one inductive elongation sensor wire makes it possible, via the measurement of the variation in inductance during the deformation of the elastic textile part, to measure variations in angles (in particular between the stretched position of a joint, for example that of the knee at 180° for a stretched leg, and the bent position of this joint, for example that of the knee at 90° when the leg is bent), to evaluate compliance (worn state or unworn state), to measure the level of tightening of the medical device on the part of the body to be treated, to measure the tension of a device, to measure the pressure exerted on the part of the body to be treated by the device.

[0036] In one embodiment, said at least one elastic textile piece exerts a compressive effect.

[0037] The device, in particular medical and / or for practicing a sport, according to the invention may thus be a stocking, tights or a compression sock, a lumbar support belt, an orthosis for supporting and / or maintaining a joint (for example of the knee, elbow, wrist, ankle or shoulder), or a compression band. In one embodiment, the elastic textile part comprises at least one localized measurement zone of the inductance (µH) comprising said at least one inductive elongation sensor wire extending between points A and B, in particular in said at least one first direction, said measurement zone being adjacent to at least one region of the elastic textile part not comprising an inductive elongation sensor wire, preferably being arranged between regions of the elastic textile part not comprising an inductive elongation sensor wire.

[0038] In particular, the surface area of the measuring zone represents less than 50%, more particularly less than 30%, even more particularly less than 20% of the total surface area of the elastic textile part.

[0039] Preferably, the conductive parts of the inductive elongation sensor wire at points A and B are electrically connected to the electrically conductive areas of an electronic card or the pins of a measuring device. Preferably, the electronic card is secured to the textile piece, for example by gluing, sewing or by being arranged in a pocket, one of the walls of the pocket being formed by the elastic textile piece comprising points A and B.

[0040] The electronic card can also be placed in a plastic box attached directly or indirectly to the textile piece.

[0041] In one embodiment, the elastic textile piece may comprise several localized measurement zones.

[0042] In this text, elastic yarn (for example: the elastic core yarn and / or yarn A and / or yarn B, and / or yarn C defined below, and / or any yarn generally different from the inductive elongation sensor yarn considered as a whole) is understood to mean a yarn having an elongation at break greater than or equal to 50%, preferably greater than or equal to 100%, and more preferably greater than or equal to 2000%, preferably greater than or equal to 300% (in particular less than or equal to 600%).

[0043] In this text, non-elastic thread, for example thread A and / or thread B, and / or thread C defined below, is understood to mean a thread having an elongation at break of less than or equal to 50%.

[0044] These elongation at break values can be determined for example using the NF EN ISO 2062 standard of January 2010. The titles (dtex) indicated in this text can be measured using the NF EN ISO 2060 standard of June 1995.

[0045] A loaded stitch is understood to mean the arrangement of a thread on a loop without the thread itself forming a loop.

[0046] In this text, the term yarn refers to a spun yarn of fibers, a multifilament yarn, a covered yarn, a monofilament yarn, or a combination of these, in particular which can undergo a knitting or weaving step.

[0047] Preferably, said elastic thread(s), in particular the elastic core thread of the inductive elongation sensor thread, is / are one or more elastic monofilament thread(s), and / or one or more elastic multifilament thread(s).

[0048] Said elastic monofilament thread(s), and / or the elastic multifilament thread(s), is / are preferably made of elastane, i.e. based on polyurethane, for example such as those marketed under the brand name Dorlastan ®<, or Lycra ®<. The elastic monofilament and / or multifilament thread(s) may also be made of latex, i.e. based on natural or synthetic rubber, such as for example elastodiene, or any other equivalent material known from the state of the art. In one embodiment, the elastic thread(s) each has / have a count greater than or equal to 250 dtex, in particular greater than or equal to 300 dtex, and less than or equal to 2000 dtex. This or these elastic thread(s) may each comprise one or more covering thread(s), such as the covering thread C according to the invention, twisted or covered.

[0049] The electrically conductive covering yarn can be arranged around the elastic core yarn by wrapping or twisting.

[0050] The elastic textile piece according to the invention also comprises at least one thread A, and optionally at least one thread B. Preferably, the thread(s) A and / or B are not electrically conductive.

[0051] In one embodiment, the elastic textile piece is knitted and comprises at least one yarn A, elastic or non-elastic, and optionally one yarn B, elastic or non-elastic, each forming stitches (loaded and / or looped), in this case called “knit yarn”, and / or is / are woven.

[0052] In this text, the term "thread", at least partly woven, is understood to mean a thread extending substantially straight in the weft direction in the woven part without forming stitches.

[0053] In another embodiment, the elastic textile piece is woven, and comprises at least a first yarn A, elastic or non-elastic, and a yarn B, elastic or non-elastic, yarn A is arranged in warp (warp yarn), and yarn B is arranged in weft (weft yarn). Yarn A may be identical to or different from yarn B.

[0054] Generally speaking, the thread(s) A and B (in particular non-elastic) and / or the covering thread(s) C defined below, is / are in one or more materials chosen from natural materials (animal, vegetable, mineral), artificial materials (cellulose-based, etc.), and synthetic materials (organic polymers, inorganic polymers), or their mixture.

[0055] Preferably, the yarn(s) A and B (in particular non-elastic) and / or the covering yarn(s) C defined below, is / are in one or more materials chosen from the group comprising: polyamide 6, polyamide 6-6, polyamide 12, polyamide 4-6, polypropylene, polyethylene, polyester such as polyethylene terephthalate, cotton, viscose, silk, wool, polyacrylic, and a mixture of these.

[0056] Preferably, the count of yarn A and / or the count of yarn B, and / or the count of yarn C, optionally elastic, is / are between 8 dtex and 700 dtex, more preferably 8 dtex and 350 dtex, in particular between 44 dtex and 350 dtex, for example less than or equal to 250 dtex. In one embodiment, the count (dtex) of yarn A and / or the count of yarn B is / are less than or equal to, in particular at least 1.5 times, the count (dtex) of the elastic core yarn of the inductive elongation sensor yarn.

[0057] Advantageously, the inductive elongation sensor wire can be implemented on a weaving loom, on a circular knitting loom or on a flat knitting loom.

[0058] The inductive elongation sensor thread can also be attached to the elastic textile piece by sewing or embroidery, although this is not preferred.

[0059] The knitted textile piece can be a warp knit (or chain knit) or a weft knit, preferably a weft knit.

[0060] Advantageously, a single inductive elongation sensor wire is sufficient to measure a deformation unlike resistive wires in the state of the art requiring the arrangement of several conductive wires in the same direction which must be in contact with each other to measure a variation in the electrical resistance.

[0061] Additionally, since fewer inductive wires according to the present invention are required to measure strain (compared to resistive wires), this limits the number of electrical connections that need to be made to collect information, and thus improves the comfort and feel of the medical device.

[0062] In one embodiment, the turns in the electrically conductive cover wire form a single layer of turns.

[0063] Indeed, in the state of the art, when we are looking for the variation of electrical conductivity, for a high number of turns / m, the turns can overlap and thus form two superimposed layers of turns.

[0064] The number of turns per meter made by a given wire (electrically conductive cover wire and / or C cover wire) on the elastic core is measured when the elastic core is at rest, i.e. in an unstretched state.

[0065] In one embodiment, the ratio corresponding to the ratio of the length of the conductive cover wire necessary to manufacture 100 cm of inductive elongation sensor wire to 100 cm of inductive elongation sensor wire is greater than or equal to 1.50 and less than or equal to 4.0; preferably greater than or equal to 2.0 and less than or equal to 3.5; in particular greater than or equal to 2.3 and less than or equal to 3.2.

[0066] Said length of the electrically conductive cover wire is obtained on 100 cm of inductive elongation sensor wire by untwisting the electrically conductive cover wire so that it has a substantially rectilinear direction.

[0067] In a variant, the turns are not contiguous, the space e between two adjacent turns is greater than 0 mm when the textile piece is at rest, in particular greater than or equal to 1 mm, more particularly less than or equal to 10 mm, in particular less than or equal to 5 mm.

[0068] The coils are not joined, that is to say they are not in contact with each other whether when the medical device is at rest (i.e. in an undeformed or elongated state) or worn (i.e. in a deformed and / or elongated state).

[0069] This characteristic is easily measured by manually removing any outer covering yarn, such as covering yarn C, either visually or using a microscope with a scale. The measurement can be carried out on an average of five samples of 3 cm to 10 cm length of inductive elongation sensor yarns recovered from one or more elastic textile piece(s).

[0070] The turns are therefore spaced apart from each other, each space revealing, between two adjacent turns, the elastic core wire.

[0071] Advantageously, the electrical resistance (in particular measured between the entry and exit points of the inductive elongation sensor wire in the elastic textile part), and therefore correlatively the electrical conductivity (ohms), remain substantially unchanged (i.e. constant(s)) when the medical device is at rest (i.e. not worn) or worn (i.e. under the normal conditions of use recommended in its instructions corresponding to a lying state).

[0072] In particular, the elastic textile part has a variation in the electrical resistivity (ohms) measured along said at least one first direction (in particular between an entry point and an exit point of the inductive elongation sensor wire), between a resting position and a stretched position, equal to 0 or less than or equal to 1 ohm, in particular less than or equal to 0.5 ohms, in particular less than or equal to 0.05 ohm.

[0073] The variation in electrical resistivity (in absolute value) is equal to the measurement of electrical resistivity measured at rest at a point A of the elastic textile piece in said at least one first direction, minus the measurement of electrical resistivity measured in the stretched position in said first direction at a point B of the elastic textile piece. The stretched position preferably corresponds to an elongation in said first direction greater than or equal to 0% and less than or equal to 150%, in particular greater than or equal to 5% and less than or equal to 100%. Said textile piece comprises at least one inductive elongation sensor wire extending between points A and B (A being different from B), in particular in said at least one first direction.

[0074] This arrangement also allows the elastic properties of the inductive elongation sensor wire to be preserved as much as possible and the quantity of “rigid” conductive cover wire to be reduced for the benefit of touch and comfort.

[0075] In an alternative embodiment, the number of turns or coils per meter of the electrically conductive covering wire around the elastic core wire is greater than or equal to 150 turns / m and less than or equal to 2500 turns / m, preferably greater than or equal to 500 turns / m and less than or equal to 2000 turns / m, in particular between 650 turns / m and 1660 turns / m (terminals included).

[0076] The inventors found that this interval allows the variation in inductance to be reliably measured and allows the core yarn to be kept sufficiently elastic to give elasticity properties to the textile piece, and possibly a compressive effect.

[0077] In one variant, the inductive elongation sensor wire comprises at least one covering wire C, in particular non-elastic.

[0078] Said covering yarn(s) C may be arranged around the elastic core yarn, in particular around the turns formed by the electrically conductive covering yarn, preferably by wrapping (i.e. single or double wrapping) or twisting.

[0079] Said covering yarn(s) C is / are preferably one or more multifilament yarn(s).

[0080] Said cover yarn(s) C have a lower count (dtex), preferably at least three times lower, preferably at least five times lower than the count (dtex) of the elastic core yarn.

[0081] Preferably, the covering wire(s) C is / are not electrically conductive. In one embodiment, the number of turns or coils per meter of the covering wire(s) C around the elastic core wire, in particular previously covered with the electrically conductive covering wire, is greater than or equal to 150 turns / m and less than or equal to 2500 turns / m, preferably greater than or equal to 500 turns / m and less than or equal to 2000 turns / m, in particular between 650 turns / m and 1660 turns / m (terminals included). In a variant, the covering wire C is arranged around the assembly formed by the electrically conductive covering wire and the elastic core wire, so as to form an outer cover.

[0082] This cover wire helps protect the electrically conductive cover wire from abrasion and during washing.

[0083] In one variant, said at least one elastic textile piece is a woven textile piece, and the inductive elongation sensor thread is a warp thread.

[0084] In one variant, said at least one elastic textile piece is a knitted textile piece, and the inductive elongation sensor yarn is woven and / or forms loaded stitches.

[0085] In both previous variants, the most rectilinear trajectory possible is sought so that the path of the inductive elongation sensor wire in the textile piece interferes as little as possible with its elongation.

[0086] In one variant, the inductive elongation sensor wire is arranged in the textile piece so that: in the case of a knitted textile piece, two adjacent rows of stitches in the weft direction, each comprising an inductive elongation sensor thread, are spaced apart by at least one row of stitches in the weft direction; or in the case of a woven textile piece, two warp threads each comprising an inductive elongation sensor thread, are adjacent, or spaced apart by at least one intermediate warp thread not comprising an inductive elongation sensor thread.

[0087] Preferably, the warp inductive elongation sensor yarn count is greater than or equal to 1 per 25.4 mm (one inch), preferably greater than or equal to 10 per 25.4 mm, and less than or equal to 100 per 25.4 mm.

[0088] Preferably, the inductive elongation sensor yarn is arranged in the weft direction in the knitted textile piece, every one row of stitches in two rows of stitches to every one row of stitches in ten rows of stitches, preferably every one row of stitches in two rows of stitches to every one row of stitches in five rows of stitches.

[0089] In one variant, the conductive core of the electrically conductive covering wire has an electrical resistivity greater than or equal to 4 ohms / m.

[0090] Preferably, the electrical resistivity is less than or equal to 25 ohms / m, less than or equal to 10 ohms / m.

[0091] In one variant, the count of the electrically conductive covering yarn is greater than or equal to 80 dtex, and less than or equal to 2000 dtex, preferably less than or equal to 500 dtex, in particular greater than or equal to 150 dtex.

[0092] In a variant, the diameter of each of the filament(s) of the electrically conductive covering wire has a substantially circular cross-section whose diameter is greater than or equal to 25 µm, preferably greater than or equal to 50 µm, and less than or equal to 500 µm, preferably less than or equal to 100 µm, in particular of the order of 63 µm.

[0093] The electrically conductive covering wire may comprise several filaments, for example between 2 and 10 filaments, in particular between 2 and 5 filaments.

[0094] In one variant, the bare elastic core yarn of the inductive elongation sensor yarn has a count greater than or equal to 250 dtex, preferably greater than or equal to 300 dtex, and less than or equal to 2000 dtex.

[0095] In one variant, the covering yarn C has a count greater than or equal to 5 dtex, and less than or equal to 700 dtex, preferably less than or equal to 250 dtex, in particular less than or equal to 100 dtex.

[0096] In one variant, the count of the inductive elongation sensor yarn is greater than or equal to 150 dtex, preferably greater than or equal to 500 dtex, and less than or equal to 4000 dtex, preferably less than or equal to 3000 dtex, in particular greater than or equal to 700 dtex and less than or equal to 2500 dtex.

[0097] In a variant, the electrically conductive covering yarn is wrapped or twisted around the elastic core yarn in a first given direction, chosen from the directions S and Z, and the covering yarn C is wrapped or twisted around the electrically conductive covering yarn in a second given direction, chosen from the directions S and Z, the first wrapping or twisting direction being opposite to the second wrapping or twisting direction.

[0098] The subject of the present invention, according to a second aspect, is the use of a device, according to any one of the variant embodiments with reference to a first aspect of the invention, for measuring the variation in the inductance (µHenry) of the magnetic coil created by said inductive elongation sensor wire between two points A and B of the elastic textile piece in at least a first direction, between which said inductive elongation sensor wire extends, obtained during the elongation of the elastic textile piece in the first direction.

[0099] The subject of the present invention, according to a third aspect, is a method for measuring the variation in the inductance (µHenry) of a magnetic coil created by an inductive elongation sensor wire, comprising the following steps: (i) providing a device according to any one of the embodiment variants with reference to a first aspect of the invention; (ii) measuring the initial inductance value I0 (µHenry) of the elastic textile piece at rest in the first direction between two points A and B between which said at least one inductive elongation sensor wire extends; (iii) measuring the inductance value I1 (µHenry) of the elastic textile piece in a first stretched state between the two points A and B, in particular under an elongation of 20 mm, in the first direction; (iv) optionally measuring the inductance value In of the elastic textile piece in an nth stretched state between the two points A and B, in particular under an elongation of 20 mm, in the first direction, n being a positive integer different from zero, the nth stretched state being different from the nth-1 stretched state;(v) recovering the variation of the inductance (µHenry) by the difference between I0 (µHenry) and I1 (µHenry), which is preferably different from zero.;

[0100] Inductance values can be measured using an LCR meter, such as the E4980A, in particular according to the following parameters: a sinusoid with a frequency of 100 kHz and an amplitude of 1 volt, the inductive strain sensor wire is connected to the device using a pair of Kelvin clamps, device reference: 16089B from Keysight Technologies. A first clamp is electrically connected to the conductive part of the inductive strain sensor wire at point A, and a second clamp is electrically connected to the conductive part of the inductive strain sensor wire at point B.

[0101] The variants, definitions, embodiments according to the first, second and third aspects can be combined independently with each other. Description of figures

[0102] The present invention will be better understood by reading the exemplary embodiments cited without limitation, and illustrated by the following figures in which: [ Fig. 1 ] there figure 1 is a schematic representation of a first example of a device, in particular a medical device, comprising a textile piece according to the present invention which is a compression sock; [ Fig. 2 ] there figure 2 schematically represents, seen from its front face, a second example of a device, in particular a medical device, comprising several textile pieces according to the invention which is a lumbar support belt; [ Fig. 3 ] there figure 3 schematically represents, seen from its rear face, the second example of a device, in particular a medical device, represented in the figure 2 ; [ Fig 4 ] there figure 4 represents a first example of a stitch pattern of a knitted textile piece according to the invention; [ Fig 5 ] there Figure 5represents a second example of a stitch pattern of a knitted textile piece according to the invention; [ Fig 6 ] there figure 6 represents a third example of a stitch pattern of a knitted textile piece according to the invention; [ Fig 7 ] there figure 7 represents a fourth example of a stitch pattern of a knitted textile piece according to the invention; [ Fig 8 ] there figure 8 schematically represents a first example of a weaving pattern of a woven piece according to the invention; [ Fig 9 ] there figure 9 schematically represents an example of an inductive elongation sensor wire according to the invention; [ Fig 10 ] there figure 10 schematically represents in cross-section the electrically conductive covering wire of the inductive elongation sensor wire shown in figure 9 . Detailed description of the invention

[0103] There figure 1 represents a first example of a medical device 1,in particular a compression sock comprising a knitted elastic textile piece with a compressive effect 5 in at least one first direction, here in the transverse direction T. The sock 1 includes an inductive elongation sensor wire 10 arranged in a circular manner between the points A1 And B1 in the measurement area z1. The measuring area z1 is arranged between regions 7 and 8 of the textile piece 5 not comprising an inductive elongation sensor wire 10. The region z1 is here arranged in the upper part of the sock 5 but could be arranged in an intermediate part depending on the area z2 or even in the lower part depending on the area z3 or even in these three areas at the same time. The arrangement of the sensor wire 10 depends on the area in which we wish to evaluate the elastic behavior of the elastic part.

[0104] In this specific example, which can be generalized to any device comprising a tubular elastic textile part, the measurement zone z1 includes several turns in the sensor wire 10. It has been observed that the greater the number of turns, the higher the measured inductance. Thus, for a number of turns between 2 turns and 10 turns, the inductance measured between the points A1 And B1 varies between 1 µH and 14 µH when the sock 5 is carried. The measured inductance also increases when the turns get closer, it is for example of the order of 3.3 µH at the carried for 5 mm of spacing between two turns of sensor wire, while it is 4 µH for 1 mm of spacing between two turns of sensor wire.

[0105] THE figures 2 And 3 represent a second example of a medical device 20,in particular a lumbar support belt, comprising several elastic textile pieces, in particular flat ones. The device 20 includes a first lateral set 22 including elastic woven textile parts 24 And 26 ; a second lateral set 28 including elastic woven textile parts 30 And 32. Woven pieces 24 And 26 respectively include a longitudinal direction corresponding to the chain direction C1 And C11 ; and a transverse direction corresponding to the weft direction T1 And T11. Woven pieces 30 And 32 respectively include a longitudinal direction corresponding to the chain direction C2 And C22 ; and a transverse direction corresponding to the weft direction T2 And T22. The first elastic direction of each of the parts 24,26, 30,32 corresponds to their longitudinal or chain direction C1, C11, C2, C22. The device 20 also includes a first central set 34 including woven textile pieces 36 And 38 elastic in their chain directions C3, C33, substantially perpendicular to their transverse directions T3, T33. The belt 20 includes sections of inductive elongation sensor wire, arranged in the textile piece 24 in the sense C1 between the points A2 And B2, in the textile room 30 between the points A3 And B3 in the sense C2, in the textile room 32 between the points A4 And B4 in the sense C22, in the textile room 36 in the sense C33 between the points A5 And B5, and finally in the textile room 26 between the points A6 And B6 in the sense C11.All of these sections of inductive elongation sensor wire 21 represent localized measurement areas adjacent to regions of these textile pieces not comprising an inductive elongation sensor wire 21.

[0106] THE figures 4 to 7 represent different stitch patterns that can be used, in combination or independently of each other, for the knitted textile piece 5 or any other knitted textile piece, in particular with a compressive effect, according to the invention.

[0107] THE Figures 4 and 5 represent stitch patterns that are implemented on a double-bed flat-bed knitting machine.

[0108] By definition, a stitch pattern is the smallest knitted repeat pattern in a knitted piece.

[0109] The mesh pattern 40 of the figure 4 includes a mesh A wire 42,elastic or not, knitted in 1*2 rib; then an inductive elongation sensor thread 44 woven, and a mesh B thread 46, elastic or not, identical or different to the mesh yarn A 42. The mesh yarn B 46 forms ribbed stitches in 1*2 rib. The sensor thread 44 is inserted between the needles of the front and back needle beds, in this specific example every one row of stitches out of three rows of stitches. Two rows of stitches in the weft direction 45, adjacent, i.e. as close as possible, each comprising an inductive elongation sensor wire 44, are spaced on the mesh diagram 40 of two rows of stitches in the weft direction 43 And 47.

[0110] The mesh pattern 50 of the Figure 5 includes a mesh A wire 52, elastic or not, knitted in 1 * 1 rib; then an inductive elongation sensor thread 44woven, ie inserted between the needles of the front and back needle beds in this specific example every one row of stitches out of two rows of stitches.

[0111] THE figures 6 and 7 represent stitch patterns that are implemented on a single cylinder circular knitting machine.

[0112] The mesh pattern 60 of the figure 6 includes a mesh A wire 62, elastic or not, knitted in reverse jersey on every other needle; then an inductive elongation sensor thread 64 forming loaded stitches on every other needle, in sync with the purl stitches of yarn A 62. The thread 64 forms loaded stitches every other row of stitches.

[0113] The mesh pattern 70 of the figure 7 includes a mesh A wire 72,elastic or not, knitted in reverse jersey on all needles; then a first inductive elongation sensor thread 74 forming loaded stitches on every other needle, then a stitch B thread 76, elastic or not, identical to or different from thread A 72, knitted in reverse stocking stitch on all needles, and finally a second inductive elongation sensor thread 78, same as or different from the first sensor wire 74, forming loaded stitches on every other needle. In this stitch pattern 70, an inductive elongation sensor wire 74, 78 is present every other row of stitches. Two rows of stitches in the weft direction adjacent i.e. as close as possible, each comprising an inductive elongation sensor thread 74 And 78 respectively, are spaced on the mesh diagram 70 of a row of stitches in the weft direction including yarn A 72or wire B 78.

[0114] There figure 8 represents an example of weaving armor 80 for the production of an elastic woven textile piece 85 can be used for textile parts 24, 26, 30, 32, 36, 38.

[0115] The textile piece 85 includes a chain direction C4 and a sense of weft T4. The room 85 is a double-sided warp fabric comprising a central layer 87 having a plurality of binding warp threads 88 and a plurality of elastic warp yarns formed from an inductive elongation sensor yarn 89. The textile piece 85 includes an outer layer 101 including binding warp threads 104 and 106 woven with weft threads 108 and 110, and the warp threads 88 And 89 of the central layer 87 as well as the warp threads 112 and 114 of the inner layer 116.The elongation sensor wire 89 is arranged in the central layer 87 and does not come into direct contact with the skin. The warp threads 88, 104, 106, 112 and 114 may be identical or different, and are of the type of yarn A according to the invention. The weft yarns 108 and 110 may be identical or different, and are of the type of wire B according to the invention.

[0116] The warp threads 88, 104, 106, 112 and 114 preferably have a title (dtex) of the same order, for example have a title of the order of 312 dtex, are multifilament yarns, and in the same material, preferably polyamide (6-6).

[0117] The weft threads 108 and 110 are preferably each a monofilament yarn, in particular made of polyamide (6-6) or polyester (polyethylene terephthalate), in particular having a diameter greater than or equal to 0.10 mm.

[0118] THE figures 9 and 10 represent an example of an inductive elongation sensor wire 120according to the invention comprising an elastic core yarn 125 and an electrically conductive cover wire 130 monofilament forming turns 135 around said elastic core wire 125. The electrically conductive covering wire 130 includes an electrically conductive core 140 covered with an electrically non-conductive sheath 145. Preferably, the number of turns 135 or turns per meter of the electrically conductive covering wire 130 around the elastic core wire 125 is between 650 rpm and 1660 rpm (terminals included). The inductive elongation sensor wire 120 preferably also includes a cover wire C 133 wrapped in a direction opposite to that given to the electrically conductive covering wire 130 in order to balance the inductive elongation sensor wire 120,and that it does not twist. The covering wire It is in particular arranged around the assembly formed by the electrically conductive covering wire 130 and elastic core yarn 125, so as to form an outer cover thus protecting the electrically conductive cover wire mechanically and during washing. The turns 135 formed by the electrically conductive covering wire 130 are not joined so that two turns 135 are spaced apart e greater than 0 mm, in particular greater than or equal to 1 mm and less than or equal to 20 mm, more particularly less than or equal to 5 mm.

[0119] The monofilament electrically conductive covering thread 130 has a count greater than or equal to 80 dtex, and less than or equal to 350 dtex. The electrically conductive covering thread 130 has a substantially circular cross-section whose diameterd is greater than or equal to 25 µm, and less than or equal to 100 µm. Generally, the diameter P of the conducting soul 140 conductive cover wire 130 is greater than or equal to 70% of the diameter d (p≥70% * d), preferably greater than or equal to 80% of the diameter d, in particular greater than or equal to 90% of the diameter d. The bare elastic core yarn 125 has a count greater than or equal to 250 dtex and less than or equal to 2000 dtex. Covering yarn C 133 has a count greater than or equal to 5 dtex, and less than or equal to 250 dtex. Finally, the count of the inductive elongation sensor yarn 120 is greater than or equal to 150 dtex, and less than or equal to 4000 dtex. Covering yarn C 133 forms coils in a direction opposite to the coils 135 formed by the conductive covering wire 130, which turns are represented on part of the length of the wire 120for the sake of clarity, while they extend along the entire length of the latter.

[0120] In a specific embodiment, the inductive elongation sensor wire 120 has a count of around 2080 dtex, a bare elastic core yarn 125 in elastane with a count of 1250 dtex, a monofilament electrically conductive covering yarn 130 whose title is 280 dtex, the conductive core 140 is made of copper and the sheath is electrically insulating 145 is in a polyamide (6-6) polymer. The diameter of the electrically conductive covering wire 130 is of the order of 63 µm. The number of turns / m, and therefore the number of turns per meter, in the electrically conductive covering wire 130 around the elastic core wire 125 is 1000 turns / m and the number of turns / m of the covering thread C 133(in 78 dtex polyamide with 2 ends) is 870 turns / m in an S or Z direction opposite to that chosen for the electrically conductive covering thread 130. Elongation at break of bare core wire 125 is of the order of 440-450%. The elongation at break of the core wire 125 covered with coils 135 in the electrically conductive covering wire 130 wireless coverage C 133, and the elongation of the inductive elongation sensor wire 120 are of the order of 190%.

[0121] In another specific embodiment, the inductive elongation sensor wire 120 has a count of around 1460 dtex, a bare elastic core yarn 125 in elastane with a count of 1250 dtex, an electrically conductive covering thread 130 whose title is 280 dtex, the conductive core 140 is made of copper and the sheath is electrically insulating 145is in at least one polymer such as polyamide (6-6) or polyurethane. The diameter of the electrically conductive covering wire 130 is of the order of 63 µm. The number of turns / m, and therefore the number of turns 135 per meter, in the electrically conductive covering wire 130 around the elastic core wire 125 is 1660 turns / m and the number of turns / m of the covering thread C 133 (in 78 dtex polyamide with 2 ends) is 1400 turns / m in an S or Z direction opposite to that chosen for the electrically conductive covering thread 130. Elongation at break of bare core wire 125 is less than or equal to 550%. The elongation at break of the core wire 125 covered with coils 135 in the electrically conductive covering wire 130 (without cover wire C), and the elongation of the inductive elongation sensor wire 120are of the order of 190%. The inductance of this inductive elongation sensor wire 120 was measured using an LCR meter and a pair of Kelvin clamps (each clamp is electrically connected to points A and B in the inductive elongation sensor wire), themselves connected to the device. The device is in particular that defined above in the description. [Table 1] Upward direction of elongation Length in cm between points A and B Upward inductance (nH) Resistance (ohm) 19 432,1 3,2 19,2 435,5 3,21 19,4 438,7 3,21 19,6 442,7 3,22 19,8 445,2 3,22 20 449,3 3,22 20,2 452 3,22 20,4 457,8 3,22 20,6 462,6 3,23 20,8 466,5 3,23

[0122] The painting 1 above represents the inductance measurements in the upward and downward direction of elongation for the inductive elongation sensor wire 120exemplified above of 1460 dtex, for a length of this inductive elongation sensor wire at rest of 19 cm. The variation of inductance in absolute values between the rest position 19 cm and the stretched position at 20.8 cm is 34.4 nH in the upward direction.

[0123] Inductance measurement advantageously allows for the reliable and significant quantification of low elongations. These measurements were carried out directly on the inductive elongation sensor wire but could also be carried out directly on the textile piece between two points of the sensor wire in the elastic textile piece.

[0124] Furthermore, the inductive elongation sensor wires exemplified in detail in the two preceding paragraphs can be implemented for the inductive elongation sensor wires 10, 21, 44, 64, 74, 78 or even 89 described above.

[0125] The zone(s) of a textile piece that is elastic in at least one direction and does not include any inductive elongation sensor thread(s) may have the same stitch or weaving pattern as that of the zone(s) that includes at least one inductive elongation sensor thread of said textile piece, or a stitch or weaving pattern chosen from those described in the present text, in which said at least one inductive elongation sensor thread is then replaced by at least one elastic thread as described in the present text.

Claims

1. A method for measuring the variation of the inductance in micro Henry (µHenry) of a magnetic coil created by an inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120), comprising the following steps: - (i) providing a device (1,20) comprising at least one elastic textile part (5, 24, 26, 30, 32, 36, 38, 85) in at least one first direction, the textile part (5, 24, 26, 30, 32, 36, 38, 85) comprising at least one inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120), said inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) comprising an elastic core yarn (125) and an electrically conductive cover yarn (130) forming turns (135) around said elastic core yarn (125), and the electrically conductive cover yarn (130) comprises a filament or a plurality of filaments, each of the or said filaments comprising an electrically conductive core (140) covered with an electrically non-conductive sheath (145); - (ii) measuring the initial inductance value I0 in micro Henry (µHenry) of the elastic textile part (5, 24, 26, 30, 32, 36, 38, 85) at rest in the first direction between two points A and B in-between which the at least one inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) extends; - (iii) measuring the inductance value I1 in micro Henry (µHenry) of the elastic textile part (10, 21, 44, 64, 74, 78, 89, 120) in a first state stretched between the two points A and B, more particularly at an elongation of 20 mm, in the first direction; - (iv) optionally measuring the value of inductance In of the elastic textile part (10, 21, 44, 64, 74, 78, 89, 120) in an nth state stretched between the two points A and B, particularly under an elongation of 20 mm, in the first direction, n being a positive integer other than zero, the nth stretched state being different from the nth-1 stretched state; - (v) recovering the variation of the inductance in micro Henry (µHenry) by the difference between I0 (µHenry) and I1 (µHenry), which is preferably different from zero.

2. The method according to claim 1, characterized in that the turns (135) are not contiguous, the space e between two adjacent turns (135) being greater than 0 mm when the textile part (5, 24, 26, 30, 32, 36, 38, 85) is at rest.

3. The method according to one or the other of claims 1 and 2, characterized in that said at least one elastic textile part comprises at least one localized measuring zone of the micro Henry inductance (µH) comprising said at least one inductive elongation sensor yarn which extends between said points A and B, said measuring zone being adjacent to at least one region of said elastic textile part not comprising said inductive elongation sensor yarn, in particular the surface area of said measuring zone represents less than 50% of the total surface area of said elastic textile part.

4. The method according to any of claims 1 to 3, characterized in that the number of turns (135) or turns per meter of the electrically conductive covering yarn (130) around the elastic core yarn (125) is greater than or equal to 150 turns / m and less than or equal to 2500 turns / m, in particular comprised between 650 turns / m and 1660 turns / m.

5. The method according to any of claims 1 to 4, characterized in that the inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) comprises at least one covering yarn C (133) which is in particular non-elastic.

6. The method according to claim 5, characterized in that the cover yarn C (133) is arranged around the assembly of the electrically conductive cover yarn (130) and of the elastic core yarn (125) so as to form an outer cover.

7. The method according to any of claims 1 to 6, characterized in that the at least one elastic textile part is a woven textile part (24, 26, 30, 32, 36, 38, 85), and the inductive elongation sensing yarn is a warp yarn (89, 120).

8. The method according to any of claims 1 to 6, characterized in that the at least one elastic textile part is a knitted textile part (5) and the inductive elongation sensor yarn is inlaid (44) and / or forms tucked stitches (64, 74, 78).

9. The method according to any of claims 1 to 8, characterized in that the inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) is arranged in said at least one elastic textile part (5, 24, 26, 30, 32, 36, 38, 85) so that: - when the elastic textile part is a knitted textile part (5), two adjacent rows of stitches in the weft direction, each comprising an inductive elongation sensor yarn (44), are spaced apart by at least one row of stitches in the weft direction (43, 57) not comprising an inductive elongation sensor yarn (88, 104, 106, 112, 114); or - when the elastic textile part is a woven textile part (89), two warp yarns each comprising an inductive elongation sensor yarn (89) are adjacent to or spaced apart from at least one intermediate warp yarn not comprising an inductive elongation sensor yarn (88, 104, 106, 112, 114).

10. The method according to any of claims 1 to 9, characterized in that the linear density of the electrically conductive covering yarn (130) is greater than or equal to 80 dtex and less than or equal to 2000 dtex.

11. The method according to any of claims 1 to 10, characterized in that the diameter of each of the filament(s) of the electrically conductive cover yarn (130) has a substantially circular cross-section having a diameter greater than or equal to 25 µm and less than or equal to 500 µm.

12. The method according to any of claims 1 to 11, characterized in that the bare elastic core yarn (125) of the inductive elongation sensor yarn (120) has a linear density greater than or equal to 250 dtex and less than or equal to 2000 dtex.

13. The method according to claim 5, characterized in that the cover yarn C (133) has a linear density greater than or equal to 5 dtex and less than or equal to 700 dtex.

14. The method according to any of claims 1 to 13, characterized in that the linear density of the inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) is greater than or equal to 150 dtex and less than or equal to 4000 dtex.

15. The method according to claim 5, characterized in that the electrically conductive cover yarn (130) is wrapped or twisted around the elastic core yarn (125) in a first given direction selected from the S and Z directions, and the C cover yarn (133) is wrapped around the electrically conductive cover yarn (130) in a second given direction selected from the S and Z directions, the first wrapping or twisting direction being opposite to the second wrapping or twisting direction.

16. A use of a device (1,20) comprising at least one elastic textile part (5, 24, 26, 30, 32, 36, 38, 85) in at least one first direction, the textile part (5, 24, 26, 30, 32, 36, 38, 85) comprising at least one inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120), said inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) comprising an elastic core yarn (125), and an electrically conductive covering yarn (130) forming turns (135) about said elastic core yarn (125), and the electrically conductive covering yarn (130) comprising a filament or several filaments, each of the or said filaments comprising an electrically conductive core (140) covered by an electrically non-conductive sheath (145), to measure the variation of the inductance in micro Henry (µHenry) of the magnetic coil created by said inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120) between two points A et B of the elastic textile part (5, 24, 26, 30, 32, 36, 38, 85) in at least a first direction, in-between which extends the inductive elongation sensor yarn (10, 21, 44, 64, 74, 78, 89, 120), obtained during the elongation of the elastic textile part (5, 24, 26, 30, 32, 36, 38, 85) in the first direction.

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