WO2023021280A1

WO2023021280A1 - Fabric article and method of making the same

Info

Publication number: WO2023021280A1
Application number: PCT/GB2022/052125
Authority: WO
Inventors: Naeem RIAZ
Original assignee: Prevayl Innovations Limited
Priority date: 2021-08-18
Filing date: 2022-08-16
Publication date: 2023-02-23

Abstract

The fabric article is knit using a knitting machine comprising a first and second needle beds. The first and second needle beds are used to knit courses of non-conductive yarn to form a first part of a base layer. The courses comprise courses of knitted loops (1602, 1604, 1608, 1610, 1614, 1616) interspersed with courses comprising tuck stitches (1606, 1612). A first of the courses of tuck stitches (1606) comprises a repeated sequence of tuck stitches. The repeated sequence comprises a tuck stitch formed using the first needle bed and a tuck stitch formed using the second needle bed. A second of the courses of tuck stitches (1612) comprises the reverse of the sequence used for the first course of tuck stitches. The second needle bed is used to knit electrically conductive yarn to form an electrode connected to the first part of the base layer.

Description

FABRIC ARTICLE AND METHOD OF MAKING THE SAME

[0001] The present disclosure is directed towards a fabric article and a method of making the same, and in particular is directed towards weft knitted fabric articles and methods of weft knitting particularly for forming fabric articles incorporating electrically conductive yarn. The fabric articles may form wearable articles such as garments.

BACKGROUND

[0002] Fabric articles comprising conductive regions such as in the form of sensing components can be designed to interface with a wearer of the article to determine information such as the wearer's heart rate and rate of respiration. The sensing components may comprise electrodes and connection terminals electrically connected together via an electrically conductive pathway. An electronics module for processing and communication can be removably coupled to the connection terminals so as to receive the measurement signals from the electrodes. The fabric articles may be incorporated into or form a wearable article such as a garment.

[0003] It is desirable to form conductive regions from conductive yarn that is knitted with a base fabric layer (base component) during a single knitting operation. This process simplifies the process of integrating electrodes into wearable articles and avoids the need for metallic or conductive polymer elements to be incorporated into a fabric. Conductive fabric electrodes are also comfortable to wear and can look, behave and feel like normal garment fabric.

[0004] Knitting conductive yarn is preferred over other techniques, such as weaving, as knitted structures are able to stretch without directly stretching the yarns used to form the knitted structure. Instead, when a knitted structure is stretched, the loops are deformed. This contrasts with woven articles where the yarns are directly stretched when the woven article is stretched. It will be appreciated that stretching a conductive yarn can change its electrical properties.

[0005] United States Patent Application Publication No. 2012/0144561 A1 discloses knitting techniques for forming three-dimensional textile electrodes. A conductive surface forming the electrode is knit using a back needle bed of a knitting machine while an isolating surface is knit using the front needle bed. A thread network is provided in a space formed between the conductive surface and the isolating surface using a tucking technique.

[0006] It is desirable to overcome at least some of the problems associated with the prior art, whether explicitly discussed herein or otherwise.

SUMMARY

[0007] According to the present disclosure there is provided a fabric article and method of making the same as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

[0008] According to a first aspect of the disclosure, there is provided a method of knitting a fabric article using a knitting machine comprises a first needle bed and a second needle bed. The method comprises forming a first part of a base layer, the forming comprises knitting, using the first needle bed and the second needle bed, a plurality of courses of non-conductive yarn, the plurality of courses of non-conductive yarn comprise courses of knitted loops interspersed with courses comprising tuck stitches. A first of the courses of tuck stitches comprises a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed using the first needle bed and a tuck stitch formed using the second needle bed. A second of the courses of tuck stitches comprises the reverse of the sequence used for the first of the courses of tuck stitches. The method further comprises forming an electrode connected to the first part of the base layer, forming the electrode comprises knitting, using the second needle bed, electrically conductive yarn to form the electrode.

[0009] Here and throughout the specification, the “first needle bed” may be a front needle bed of a knitting machine and the “second needle bed” may be a back needle bed of a knitting machine. Alternatively, the first needle bed may be the back needle bed and the second needle bed may be the front needle bed.

[0010] Advantageously, the present disclosure provides a knitted fabric article (a continuous body of fabric) that comprises an electrode integrally formed with a base layer. This simplifies the manufacturing process as the electrode and base layer are manufactured during a single knitting operation. The fabric article structure simplifies the knitting techniques required to form the electrode integrally with the base layer. That is, the fabric article structure facilitates the manufacture of the continuous body of fabric in a single knitting operation.

[0011] Further, as the electrode is knitted, the electrode is able to stretch with the base layer without the electrical properties (e.g. the resistivity) of the electrode being affected. This is because when a knitted article is stretched, the yarn is not directly stretched, but rather the stitches are deformed. This contrasts with woven articles where the yarns are directly stretched when the woven article is stretched. It will be appreciated that stretching a conductive yarn can change its electrical properties.

[0012] Moreover, providing the electrode as part of a singular fabric structure means that the fabric article may handle, feel, behave and looks like a fabric without requiring wiring, soldering or physical connections to provide the required sensing functionality.

[0013] The base layer comprises courses of knitted loops interspersed with courses comprising tuck stitches. A first of the courses of tuck stitches comprises a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed using the first needle bed and a tuck stitch formed using the second needle bed. A second of the courses of tuck stitches comprises the reverse of the sequence used for the first of the courses of tuck stitches. This arrangement of tuck stitches provided between rows of knitted loops adds compression to the base layer and helps the base layer urge the electrode against a skin surface of a wearer of the fabric article.

[0014] The sequence of tuck stitches may comprise one or more float stitches between tuck stitches, the one or more float stitches may be provided between the tuck stitch formed using the first needle bed and the tuck stitch formed using the second needle bed. [0015] Knitting the plurality of courses of non-conductive yarn may comprise knitting a repeating sequence of courses. The sequence may comprise knitting at least one course of non-conductive yarn comprising knitted loops, and knitting a course of tuck stitches.

[0016] Knitting the at least one course of non-conductive yarn may comprise knitting a first course of non-conductive yarn comprising knitted loops using a first knitting sequence, and knitting a second course of non-conductive yarn comprising knitted loops using a second knitting sequence. The second knitting sequence is the reverse of the first knitting sequence such that stitches performed on the first needle bed in the first course are performed on the second needle bed in the second course, and stitches performed on the second needle bed in the first course are performed on the first needle bed in the second course.

[0017] Knitting the first course may use a first yarn and knitting the second course may use a second yarn.

[0018] In the first course, the first yarn may cross between the first needle bed and the second needle bed at one or more needle locations. In the second course, the second yarn may cross between the first needle bed and the second needle bed at the one or more needle locations.

[0019] Knitting the first course may comprise forming knitted loops using the first needle bed, and knitting the second course may comprise forming knitted loops using the second needle bed.

[0020] Knitting the first courses may comprise forming knitted loops using the first needle bed and forming tuck stitches using the second needle bed, and knitting the second course may comprises forming tuck stitches using the first needle bed and knitted loops using the second needle bed. The first and second course may therefore comprise tuck-rib stitches knitted in a two-course repeat manner. These tuck-rib stitches are referred to as full-cardigan stitches.

[0021] The electrode may form a three-dimensional surface that extends away from the base layer. The electrode may be formed by knitting, using the second needle bed, a plurality of rows of electrically conductive yarn. The plurality of rows may comprise P rows of stitches. P may be between 1 and 30, 5 and 30, 10 and 30, 15 and 30, or 25 and 30. P may be between 1 and 25, 1 and 20, 1 and 15, 1 and 10 or 1 and 5. Most preferably, P is between 10 and 20. The present disclosure is not limited to any particular number of row of stitches. The number of rows may vary based on factors such as the thickness of the yarn or the machine gauge (number of needles per inch of the needle bed).

[0022] The electrode may extend to a height of between 0.2 mm and 30 mm from the first surface of the base component. The electrode may extend to a height of between 0.2 mm and 25 mm, 0.2 mm and 20mm, 0.2 mm and 15mm, 0.2 mm and 10mm, 0.2 mm and 5 mm, 0.2 mm and 2 mm, and 0.2 mm and 1 mm. The electrode may extend to a height of between 0.5 mm and 30 mm, 1 mm and 30 mm, 2 mm and 30 mm, 5 mm and 30mm, 10mm and 30mm, 15mm and 30mm, 20mm and 30mm, and 25mm and 30mm. In some examples, the electrode extends to a height of between 2 mm and 5 mm. The present disclosure is not limited to any particular height of electrode. The height may vary based on factors such as the sensing application. [0023] The electrode may form a tube extending from the base layer. The tube may have an apex spaced apart from the base layer. The electrode may define a convex outer surface. The tube may comprise one a plurality of rows of conductive yarn. Each row may comprise a plurality of stitches of yarn. The tube may have a generally elongate shape with a raised convex outer surface.

[0024] The method may also comprise knitting, using the first needle bed and the second needle bed, a plurality of courses of non-conductive yarn to form a further part of the base layer connected to the first part of the base layer and the electrode, the plurality of courses of non-conductive yarn comprising courses of knitted loops interspersed with courses comprising tuck stitches, a first of the courses of tuck stitches comprising a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed using the first needle bed and a tuck stitch formed using the second needle bed, a second of the courses of tuck stitches comprising the reverse of the sequence used for the first of the courses of tuck stitches.

[0025] The method may also comprise knitting, using the first needle bed or the second needle bed, electrically conductive yarn to form a connection region and a conductive pathway that extends from the electrode to the connection region and electrically connects the electrode to the connection region.

[0026] According to a second aspect of the disclosure, there is provided a computer program comprising instructions recorded thereon which, when executed by a computer associated with a knitting machine, are operable to cause the computer to control the knitting machine to perform the method of the first aspect of the disclosure.

[0027] According to a third aspect of the disclosure, there is provided a knitted fabric article comprising a base layer comprising a first knit layer and a second knit layer, the base layer comprising a plurality of courses of non-conductive yarn, the plurality of courses of non-conductive yarn comprising courses of knitted loops interspersed with courses comprising tuck stitches, a first of the courses of tuck stitches comprising a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed on the first knit layer and a tuck stitch formed on the second knit layer, a second of the courses of tuck stitches comprising the reverse of the sequence used for the first of the courses of tuck stitches. The knitted fabric article further comprising an electrode formed from electrically conductive yarn and connected to the base layer.

[0028] The knitted fabric article may also comprise a connection region and a conductive pathway formed from electrically conductive yarn, wherein the conductive pathway extends from the electrode to the connection region and electrically connects the electrode to the connection region.

[0029] According to a fourth aspect of the disclosure, there is provided a method of knitting a fabric article using a knitting machine comprising a first needle bed and a second needle bed. The method comprises knitting, using the first needle bed and the second needle bed, at least one course of non-conductive yarn to form a first part of a base layer, the at least one course of non- conductive yarn comprising knitted loops. The method comprises knitting, using the second needle bed, a plurality of courses of electrically conductive yarn to form a first part of an electrode, the plurality of courses of conductive yarn comprising knitted loops. A first of the plurality of courses if conductive yarn is connected to the first part of the base layer. The method comprises knitting, using the first needle bed, a plurality of courses of non-conductive yarn and a plurality of courses of filler yarn to form a second part of the base layer, wherein each course of filler yarn is provided between two courses of non-conductive yarn, each course of filler yarn comprises tuck stitches separated by one or more float stitches, and a first of the plurality of courses of non-conductive yarn is connected to the first part of the base layer.

[0030] The filler yarn may be bulkier than the non-conductive yarn

[0031] Knitting the plurality of courses of non-conductive yarn and the plurality of courses filler yarn to form the second part of the base layer comprises knitting at least one course of non- conductive yarn using knitted loops separated by one or more float stitches.

[0032] The at least one course of non-conductive yarn may comprise one float stitch for every knitted loop.

[0033] The number of float stitches per tuck stitch for the at least one course of filler yarn may be greater than the number of float stitches per knitted loop for the at least one of the plurality of courses of non-conductive yarn comprising knitted loops separated by one or more float stitches.

[0034] The at least one course of filler yarn may comprise at least two float stitches for every tuck stitch.

[0035] The at least one course of filler yarn may comprise at least three float stitches for every tuck stitch.

[0036] Knitting the plurality of courses of non-conductive yarn and the plurality of courses of filler yarn to form the second part of the base layer may comprise knitting a plurality of pairs of courses, each pair comprising a first course of filler yarn comprising tuck stitches separated by one or more float stitches and a second course comprising non-conductive yarn.

[0037] Different needle locations may used to form the tuck stitches in adjacent pairs of courses.

[0038] The filler yarn may be an expanding yarn.

[0039] The method may also comprise applying an external stimulus to the fabric article so as to cause the expanding yarn to expand.

[0040] Knitting at least one course of non-conductive yarn to form the first part of the base layer may comprise knitting a plurality of courses of non-conductive yarn.

[0041] The plurality of courses may comprise a plurality of pairs of courses, each pair comprising a first course knitted using a first yarn and a second course knitted using a second yarn.

[0042] The second course in each pair may use the reverse of the knitted sequence used for the first course in the pair such that knitted loops formed on the first needle bed in the first course are formed on the second needle bed in the second course, and knitted loops formed on the second needle bed in the first course are formed on the first needle bed in the second course.

[0043] The knitted courses may comprise cardigan stitches.

[0044] The cardigan stitches may be half-cardigan stitches.

[0045] The cardigan stitches may be full-cardigan stitches. [0046] The method may further comprise knitting, using the second needle bed, a plurality of courses of electrically conductive yarn to form a second part of the electrode, the plurality of courses of conductive yarn comprising knitted loops, and wherein a first of the plurality of courses is connected to the last of the plurality of courses of the first part of the electrode and a last of the plurality of courses is held on the second needle bed.

[0047] Knitting at least one course of non-conductive yarn to form the third part of the base layer may comprise knitting a plurality of courses of non-conductive yarn.

[0048] The method may also comprise knitting, using the first needle bed and the second needle bed, at least one course of non-conductive yarn to form a third part of the base layer, wherein the third part of the base layer is connected to the last of the plurality of courses of the second part of the base layer and the last of the plurality of courses of the second part of the electrode.

[0049] According to a fifth aspect of the disclosure, there is provided a computer program comprising instructions recorded thereon which, when executed by a computer associated with a knitting machine, are operable to cause the computer to control the knitting machine to perform the method of the fourth aspect of the disclosure.

[0050] According to a sixth aspect of the disclosure, there is provided a fabric article comprising a base layer comprising a first part formed from at least one course of non-conductive yarn, the first part comprising first and second fabric layers, a second part formed from a plurality of courses of non-conductive yarn interspersed with courses of filler yarn such that each course of filler yarn is provided between two courses of non-conductive yarn, wherein each course of filler yarn comprises tuck stitches separated by one or more float stitches, and wherein the second part of the base layer comprises a first fabric layer connected to the first fabric layer of the first part. The base layer also comprises a third part formed from at least one course of non-conductive yarn, the third part comprising first and second fabric layers, the first fabric layer being connected to the first fabric layer of the second part. The fabric article also comprises an electrode formed from a plurality of courses of electrically conductive yarn, the electrode being connected to the first part of the base layer and the third part of the base layer.

[0051] According to a seventh aspect, there is provided a method of knitting a fabric article using a knitting machine comprising a first needle bed and a second needle bed, the method comprising knitting, using the first needle bed and the second needle bed, non-conductive yarn using a first group of needle locations to form a first part of a base layer. The method also comprises knitting, using the first needle bed, a plurality of rows of non-conductive yarn using a second group of needle locations contained within the first group of needle locations to form a pocket layer. A first of the rows is connected to the first part of the base layer. The method also comprises knitting, using the second needle bed, electrically conductive yarn using a third group of needle locations contained within the second group of needle locations to form a first part of a first connection region. The first part of the first connection region being connected to the first part of the base layer. The method also comprises knitting, using the second needle bed, electrically conductive yarn using the third group of needle locations to form a second part of a first connection region. The second part of the first connection region being connected to the first part of the connection region. The method also comprises knitting, using the first needle bed and the second needle bed, non-conductive yarn using the first group of needle locations to form a further part of the base layer, the further part of the base layer being connected to the first part of the base layer, the second part of the first connection region, and the pocket layer.

[0052] Advantageously, the method forms a fabric article comprising a base layer and an integrally knit pocket layer. The pocket layer overlaps a first electrically conductive region such that the first electrically conductive region is provided within the pocket space. This simplifies the manufacturing process as it avoids the needs to separately attach a pocket layer to the fabric article such as by stitching or bonding.

[0053] The method may also comprise knitting, using the first or second needle bed, electrically conductive yarn using a fourth group of needle locations contained within the first group of needle locations and separate from the second group needle locations to form a first part of a first conductive pathway, the first part of the first conductive pathway being connected to the first part of the base layer and the first part of the first connection region. The method may also comprise knitting, using the first or second needle bed, electrically conductive yarn using the fourth group of needle locations to form a second part of the first conductive pathway, the second part of the first conductive pathway being connected to the first part of the first conductive pathway.

[0054] The method may also comprise knitting, using the second needle bed, electrically conductive yarn to form a first electrode, the first electrode being knitted using a fifth group of needle locations contained within the first group of needle locations and separate from the second group needle locations and the fourth group of needle locations used to form the first conductive pathway. The first electrode is connected to the first part of the base layer, the second part of the base layer, the first part of the first conductive pathway, and the second part of the first conductive pathway.

[0055] Knitting electrically conductive yarn to form the first electrode may comprise knitting a plurality of rows of conductive yarn.

[0056] The method may also comprise knitting, using the second needle bed, electrically conductive yarn using a sixth group of needle locations contained within the second group of needle locations and separate from the third group of needle locations to form a first part of a second connection region, the first part of the second connection region being connected to the first part of the base layer. The method may also comprise knitting, using the second needle bed, electrically conductive yarn using the sixth group of needle locations to form a second part of the second connection region, the second part of the second connection region being connected to the first part of the second connection region.

[0057] The method may also comprise knitting, using the first or second needle bed, electrically conductive yarn using a seventh group of needle locations contained within the first group of needle locations and separate from the second group needle locations to form a first part of a second conductive pathway, the first part of the second conductive pathway being connected to the first part of the base layer and the first part of the second connection region. The method may also comprise knitting, using the first or second needle bed, electrically conductive yarn using the seventh group of needle locations to form a second part of the second conductive pathway, the second part of the second conductive pathway being connected to the first part of the second conductive pathway.

[0058] The method may also comprise knitting, using the second needle bed, electrically conductive yarn to form a second electrode, the second electrode being knitted using an eighth group of needle locations contained within the first group of needle locations and separate from the second group needle locations and the seventh group of needle locations used to form the second conductive pathway, the second electrode being connected to the first part of the base layer, the second part of the base layer, the first part of the second conductive pathway, and the second part of the second conductive pathway.

[0059] According to an eighth aspect of the present disclosure, there is provided a computer program comprising instructions recorded thereon which, when executed by a computer associated with a knitting machine, are operable to cause the computer to control the knitting machine to perform the method of the seventh aspect of the disclosure.

[0060] According to a ninth aspect of the present disclosure, there is provided a knitted fabric article comprising a base layer comprising first and second knit layers, the base layer comprising non-conductive yarn, a pocket layer comprising a single knit layer, the pocket layer comprising a plurality of rows of non-conductive yarn, and a first connection region comprising electrically conductive yarn, and wherein the pocket layer is connected to the base layer and overlaps the base layer in an overlapping region, and wherein the first connection region is connected to the base layer and is provided in the overlapping region.

[0061] The knitted fabric article may also comprise a first conductive pathway comprising electrically conductive yarn, the first conductive pathway being connected to the base layer and being provided outside of the overlapping region.

[0062] The knitted fabric article may also comprise a first electrode comprising electrically conductive yarn, the first electrode being connected to the base layer and being provided outside of the overlapping region.

[0063] The first electrically conductive pathway may electrically connect the first connection region to the first electrode.

[0064] The knitted fabric article may also comprise a second connection region comprising electrically conductive yarn, the second connection region is connected to the base layer and is provided in the overlapping region.

[0065] The knitted fabric article may also comprise a second conductive pathway comprising electrically conductive yarn, the second conductive pathway being connected to the base layer and being provided outside of the overlapping region.

[0066] The knitted fabric article may also comprise a second electrode comprising electrically conductive yarn, the second electrode being connected to the base layer and being provided outside of the overlapping region. [0067] The second electrically conductive pathway may electrically connect the second connection region to the second electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0069] FIG. 1 is a simplified schematic side-on view of a V-bed knitting machine.

[0070] FIG. 2 is a simplified schematic top-down views of the front and back beds of the knitting machine in FIG. 1 .

[0071] FIG. 3 is a simplified schematic top-down views of the front and back beds of the knitting machine in FIG. 1 .

[0072] FIG. 4 is a simplified schematic top-down views of the front and back beds of the knitting machine in FIG. 1 .

[0073] FIG. 5 is a knitting notation diagram showing a method of knitting loops using the front needle bed of a knitting machine.

[0074] FIG. 6 is a knitting notation diagram showing a method of knitting loops using the back needle bed of a knitting machine.

[0075] FIG. 7A shows the front surface of a fabric article knitted according to the methods shown in FIG. 5 or FIG. 6.

[0076] FIG. 7B shows the back surface of a fabric article knitted according to the methods shown in FIG. 5 or FIG. 6.

[0077] FIG. 8 is a knitting notation diagram showing a method of knitting loops using both the front bed and the back bed of a knitting machine.

[0078] FIG. 9 is a knitting notation diagram showing a method of knitting tuck-stitches using the front bed or the back bed of a knitting machine.

[0079] FIG. 10 is a knitting notation diagrams showing a method of knitting tuck-stitches using the front bed or the back bed of a knitting machine.

[0080] FIG. 11 is a knitting notation diagram showing a method of knitting a combination of knitting loops and float stitches and a combination of tuck-stitches and float-stitches using the front and/or back bed of a knitting machine.

[0081] FIG. 12 is a knitting notation diagram showing a method of knitting full-cardigan stitches using a knitting machine.

[0082] FIG. 13 shows a fabric article with full-cardigan stitches.

[0083] FIG. 14 illustrates the knitting operations used to form a fabric article according to aspects of the present disclosure.

[0084] FIG. 15A illustrates the top surface of a fabric article formed using the knitting operations of FIG. 14.

[0085] FIG. 15B illustrates a bottom surface of the fabric article of FIG. 15A. [0086] FIG. 15C illustrates the top surface of the fabric article of FIG. 15A with the pocket layer removed.

[0087] FIG. 15D illustrates a side surface of the fabric article of FIG. 15A.

[0088] FIG. 16 is a knitting notation diagram showing an example method of knitting a base layer according to aspects of the present disclosure.

[0089] FIG. 17 is a knitting notation diagram showing an example method of knitting a base layer according to aspects of the present disclosure.

[0090] FIG. 18 is a knitting notation diagram showing an example method of knitting a base layer according to aspects of the present disclosure.

[0091] FIG. 19A is a first part of a knitting notation diagram showing an example method of knitting a fabric article comprising an electrode according to aspects of the present disclosure.

[0092] FIG. 19B is a second part of a knitting notation diagram shown in FIG. 19A.

[0093] FIG. 20A shows the bottom surface of a fabric article formed using the knitting operations of FIG. 19A and Fig. 19B.

[0094] FIG. 20B illustrates the side of the fabric article of Fig. 20A.

[0095] FIG. 20C illustrates the top of the fabric article of Fig. 20A.

[0096] FIG. 21 A is a first part knitting notation diagram showing an example method of knitting a base layer with an integral pocket according to aspects of the present disclosure.

[0097] FIG. 21 B is a second part of the knitting notation diagram of FIG. 21 A.

DETAILED DESCRIPTION

[0098] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

[0099] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

[0100] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. [0101] The present disclosure relates to fabric articles. The terms fabric and textile are used interchangeably and are not intended to convey different meanings. The fabric articles are knitted from yarns.

[0102] The fabric articles may form or be incorporated into a wearable article. “Wearable article” as referred to throughout the present disclosure may refer to any form of article which may be worn by a user such as a smart watch, necklace, bracelet, or glasses. The wearable article may be a garment. The garment may refer to an item of clothing or apparel. The garment may be a top. The top may be a shirt, t-shirt, blouse, sweater, jacket/coat, or vest. The garment may be a dress, brassiere, shorts, pants, arm or leg sleeve, vest, jacket/coat, glove, armband, underwear, headband, hat/cap, collar, wristband, stocking, sock, or shoe, athletic clothing, personal protective equipment, swimwear, wetsuit or drysuit

[0103] The garment may be a tight-fitting garment. Beneficially, a tight-fitting garment helps ensure that the sensor devices of the garment are held in contact with or in the proximity of a skin surface of the wearer. The garment may be a compression garment. The garment may be an athletic garment such as an elastomeric athletic garment.

[0104] The fabric articles may be constructed from natural fibres, synthetic fibres, or a natural fibre blended with one or more other materials which can be natural or synthetic. The yarn may be cotton. The cotton may be blended with polyester and/or viscose and/or polyamide according to the particular application. Silk may also be used as the natural fibre. Cellulose, wool, hemp and jute are also natural fibres that may be used in the wearable article. Polyester, polycotton, nylon and viscose are synthetic fibres that may be used in the wearable article.

[0105] The fabric articles according to the present disclosure comprise knitted fabric. This contrasts with other fabric constructions such as woven fabrics. Woven and knitted fabrics differ in the way yarns are interwoven or knotted together. A woven fabric is created by interweaving pretensioned lengths of yarn horizontally in between threads running vertically. These vertical, or warp threads, wrap themselves around the horizontal, or weft thread, after every course, and are themselves pre-tensioned.

[0106] During the manufacture of a woven fabric, all of the yarns running in every direction must be pulled tight at all teams. If the yarns are not tight during knitting, the needles will snag on slacker yarns and break, causing mechanical damage.

[0107] Moreover, woven fabrics incorporating conductive yarn are potentially subjected to a change of resistance when stretched apart because, when stretching a woven fabric, the yarns and thus the conductive particles in the yarn will be stretched further apart. This property is undesirable for sensing operations such as for fabric-based sensing electrodes.

[0108] The present disclosure is directed towards knitted fabrics and, in particular, weft knitted fabrics. Weft knitted fabrics can be knit from a single yarn, but in aspects of the present disclosure multiple yarns are used so as to provide different regions of the fabric with different properties. In weft knitted fabrics, a weft thread is pulled through already formed loops of the same thread and, unlike warp knitting, is not required to be held taut or under stress from a warp thread. This construction allows for stitches (loops) in the fabric article to deform and alter their shape under stress without stretching the yarn itself. This helps maintain a constant level of electrical resistance.

[0109] Warp knitted fabrics are another form of knitted article and can be considered a hybrid between woven and knitted. They are formed using loops, but each column of loops is made from its own thread. Warp knitted threads may allow for more stretch than a woven fabric but are generally not as stretchy as weft knitted fabrics.

[0110] To aid in the understanding of the invention, a brief overview of knitting machines and the stitches that knitting machines can generate is provided below in reference to FIG. 1 to FIG. 13. This explanation is not intended to be a full disclosure of the common general knowledge of the skilled person, but instead is only provided to aid in the understanding of the invention.

[0111] FIG. 1 shows a simplified schematic diagram of a conventional V-bed flat knitting machine 102 which is suitable for use in knitting the fabric articles described herein.

[0112] The V-bed flat knitting machine 102 comprises a front needle bed 104 and a back needle bed 106. The front needle bed 104 and back needle bed 106 diagonally approach one another at an angle generally between 90 degrees and 104 degrees to each other, giving an inverted V-shape appearance.

[0113] The front needle bed 104 and back needle bed 106 each comprise a large number of needles 108, 110. The needles 108, 110 are typically latch needles. Each needle 108, 110 is able to create and manipulate individual stitches.

[0114] The number of needles per inch is referred to as the gauge of the knitting machine 102. Typically, knitting machines have a gauge of between 7 and 20.

[0115] The needles 102, 104 are controlled by a needle cam 112 that traverses across the needle beds 104, 106 in both left-to-right and right-to-left directions. The needle cam 112 is designed to knit a course of loops on one or both the front needle bed 104 and the back needle bed 106 during a traverse in either the left or the right direction.

[0116] Yarn is fed to the needle beds 104, 106 by one or more yarn carriers (not shown). Multiple yarn carriers are typically used to allow for a variety of yarns to be introduced into the fabric article at desired locations.

[0117] The needle beds 104, 106 are able to move relative to one another by a process called racking. Racking moves one of the needle beds by one or more needle tricks past the other needle bed, either towards the right or the left. A needle trick is a slot on the needle bed in which a needle moves back and forth. The front and back needle beds 104, 106 are aligned in FIG. 2. In FIG. 3, the back needle bed 106 has been racked to the left relative to the front needle bed 104. In FIG. 4, the back needle bed 106 has been racked to the right relative to the front needle bed 104.

[0118] For most knitting machines, only the back needle bed 106 is able to be racked while the front needle bed 104 stays in a fixed position. However, this is not true for all machines, and front needle beds 104 may also be racked if desired. Racking is not required for knitting, but may be used to create certain effects in the resultant knitted article. [0119] FIG. 5 shows an example knitting notation diagram in which a plurality of courses of knitted loops are formed using the front needle bed of the knitting machine.

[0120] The diagram comprises several rows of dots where each dot represents a needle on either the front needle bed or the back needle bed.

[0121] The rows are grouped into pairs (502, 504, 506, 508, 510, 512). In each pair, one row represents needles on the front needle bed and the other row represents needles on the back bed. In each pair, the needles on the front bed are arranged vertically below the needles on the back bed. Each pair of dots show the knitting operations performed to form a knitted course (row of stitches) of the fabric article. A knitted course may also be referred to as a traverse.

[0122] The type of knitting operation performed is represented by the lines that traverse along the dots. Here, the knitting operations are knitted loops as indicated by the lines looping around the dots representing needles on the front bed.

[0123] The diagram is read from bottom to top. This means that the knitting operations represented by pair 502 are performed first followed by 504, 506, 508, 510, 512 in order. Each of the knitting operations 502 - 512 involve forming knitted loops using the front needle bed only. The back needle bed is not used. The resultantly formed knitted fabric article comprises six courses of knitted loops where each course comprises three stitches.

[0124] FIG. 6 shows an example knitting notation diagram in which a plurality of courses of knitted loops are formed using the back bed of the knitting machine. Each of the knitting operations 602-612 involve forming knitted loops using back needle bed only. The front needle bed is not used. The resultantly formed knitted fabric article comprises six courses of knitted loops where each course comprises three stitches.

[0125] Reference to “course” or “row” throughout this specification will not be understood as necessarily referring to a full-width course that extends along the full-width of the needle bed or the fabric article unless otherwise specified. Course instead just refers to a row of stitches formed by the knitting machine. Course contrasts with “wales” which refer to columns of vertical stitches formed by the knitting machine.

[0126] FIG. 7A and FIG. 7B show a knitted fabric article 702 that may be formed as a result of front-bed only knitting using the techniques shown in FIG. 5 or back-bed only knitting using the techniques shown in FIG. 6. The knitted fabric article 702 is a single-faced structure as only one of the needle beds is used to form the knitted loops. FIG. 7A shows the face 704 of the knitted fabric article 702 and FIG. 7B shows the back 706 of the knitted fabric article 702.

[0127] FIG. 8 shows an example knitting notation diagram in which a plurality of courses of knitting loops are formed using both the front and back needle beds. Each of the knitting operations 802-814 involve forming knitted loops using both the front and the back needle bed. This can be referred as double-knitting. The resultantly formed knitted article comprises a number of courses of knitted loops and has a double-faced structure as compared to the single-faced structure of the fabric article formed using the operations shown in FIG. 5 and FIG. 6. [0128] FIG. 9 and FIG. 10 show example knitting notation diagram in which a plurality of courses (902-912 and 1002-1014) of tuck stitches are formed using the front needle bed only (FIG. 10) or using the back needle bed only (FIG. 10). Tuck stitches are produced when a needle holding an existing loop also receives a new loop which rather than being intermeshed through the existing loop is tucked in behind the existing loop on the reverse side of the stitch. Tuck stitches are represented in the diagram by as a “V” (or inverted “V”) shape that goes around the needle that performs the tuck stitch.

[0129] FIG. 11 is an example knitting notation diagram in which float stitches are interspersed between other needle stitches. Float stitches are produced when a needle misses the yarn which instead floats over to the next chosen needle. Floats are represented in the needle diagram as a bypassed point.

[0130] Knitting operation 1102 involves a series of knitted loops on the front needle bed with float stitches in between. In other words, every other needle on the front needle bed is used to knit a loop.

[0131] Knitting operation 1104 involves a series of knitted loops on the back needle bed with float stitches in between,

[0132] Knitting operation 1106 involves a series of tuck stitches on the back needle bed with float stitches in between.

[0133] Knitting operation 1108 involves a series of tuck stitches on the front needle bed with float stitches in between.

[0134] Knitting operation 1110 involves a series of tuck stitches alternatingly performed on the front needle bed and the back needle bed with float stitches in between.

[0135] Tuck-rib stitches are another form of knit structure formed by using knitted loops on one needle bed and tuck-stitches on the other needle bed. Tuck-rib stitches can be used in full-cardigan stitches.

[0136] FIG. 12 is an example knitting notation diagram which shows a series of full-cardigan stitches. Full-cardigan stitches use repeating pairs of knit courses where the second course in each pair uses the reverse of the stitches used for the first course in each pair. The first and second courses both use tuck stitches on one needle bed and knitted loops on the other needle bed.

[0137] The tuck stitches cause the rib wales to gape apart so that the body width spreads outwards to a greater extent than the rib border. Tuck loops can increase the fabric thickness and make it heavier in weight and bulkier in handle.

[0138] The knitting operation 1202 is a sequence of knitted loops on the front bed and tuck stitches on the back bed. The knitting operation 1204 is the reverse of the sequence of 1202 and has tuck stitches on the front bed and knitted loops on the back bed. Operations 1206- 1212 are a repetition of the sequences 1202 and 1204.

[0139] FIG. 13 shows a knitted fabric article 1302 formed as a result of the knitting operations of FIG. 12. The full-cardigan stitches result in a balanced 1 x 1 tuck-rib structure with the same appearance when viewed from both faces of the fabric. This drawing is obtained from the textbook: Knitting technology (2001) David J Spencer, Third edition, Woodhead Publishing Limited, Cambridge, UK (Figure 18.6, page 219).

[0140] FIG. 14 shows an example knitting sequence for forming a fabric article comprising electrodes according to aspects of the present disclosure. Different numbered blocks in the Figure represent different parts of the fabric article formed as a result of the knitting sequence. The knitting operation is performed in one go such that the fabric article is a continuous body of weft knitted fabric. The knitting sequence is read from bottom to top. This means that the part numbered 1402 is knitted first and the part numbered 1426 is knitted last.

[0141] The knitting sequence is performed using a knitting machine, such as a V-bed flat knitting machine, comprising a front needle bed and a back needle bed. The knitting involves using different types of yarns held on different yarn carriers of the knitting machine.

[0142] A first part of base layer 1402 is knit using both the front needle bed and the back needle bed. The front needle bed and the back needle bed may be used on different (e.g., alternate courses) or may be used together to form a knit course. The first part of base layer 1402 has a double layer structure as knitted loops are formed on the front needle bed and the back needle bed (although not necessarily simultaneously). The first part of base layer 1402 has a front layer formed by the front needle bed and a back layer formed by the back needle bed. The first part of base layer 1402 is a double-faced structured.

[0143] The first part of base layer 1402 comprises a plurality of knit courses. The plurality of knit courses use a first group of needle locations on the knitting machine. The first group of needle locations define the width (in the course direction) of the fabric article. The knit courses may be referred to as full-width courses.

[0144] The first part of base layer 1402 is knitted using non-conductive yarn. Any non- conductive yarn may be used to form the first part of base layer 1402. The yarn may be formed from natural or synthetic fibres or may be blend of natural and synthetic fibres. An example non- conductive yarn is a composite fabric elastomeric yarn. In particular, a composite fabric elastomeric yarn comprising 81 % nylon and 19% elastane. Of course other non-conductive yarns may be used as desired by the skilled person.

[0145] Multiple different types of non-conductive yarn may be used in knitting the first part of base layer 1402. The multiple different types of yarns may include yarns with different colours but which may otherwise have the same properties. A combination of different coloured yarns can be used to create pattern effects in the base layer. The multiple different yarns may additionally or separately have different properties.

[0146] Examples of knitting operations used to form the first part of base layer 1402 are described in FIG. 16, FIG. 17 and FIG. 18.

[0147] A pocket layer 1404 is knitted using the front needle bed only. The pocket layer 1404 is formed by knitting a plurality of rows of knitted loops (courses) using the front needle bed. The plurality of rows of knitted loops extend along a partial width of the fabric article and may be referred to as partial courses rather than full-width courses. The pocket layer 1404 is knit using a second group of needle locations which is contained within the first group of needle locations used to knit the first part of the base layer. In this example, the second group of needle locations are located in the approximate centre of the first group of needle locations.

[0148] As knitting of the pocket layer 1404 is performed only on the front needle bed, an excess of material is formed and held on the front needle bed. The pocket layer 1404 has a single layer structure.

[0149] The pocket layer 1404 is knitted using non-conductive yarn and may use the same or one of the same yarns as used to form the first part of base layer 1402. The pocket layer 1404 forms part of the front layer of the fabric article.

[0150] A first part of first connection region 1406 is knitted using the back needle bed. The first part of the first connection region 1406 is knit using a third group of needle locations contained within the second group of needle locations. As the first part of first connection region 1406 is knitted using the back needle bed it is formed behind the pocket layer 1404 and is covered by the pocket layer 1404 in use. The first part of first connection region 1406 forms part of the back layer of the fabric article. The first part of first connection region 1406 comprises a plurality of rows of knitted loops (courses). The plurality of rows that form the first connection region 1406 extend along a partial width of the fabric article and may be referred to as partial courses.

[0151] The first part of first connection region 1406 is knit using electrically conductive yarn. The electrically conductive yarn ("conductive yarn") may be any form of yarn that is electrically conductive. The conductive yarn may be formed from a conductive metal such as copper, silver or stainless-steel. The conductive yarn may comprise a non-conductive or less conductive base yarn which is coated or embedded with conductive material such as carbon, copper or silver. The conductive yarn may be a stainless-steel yarn such as those manufactured by TIBTECH Innovations. The conductive yarn may comprise silver bonded to a nylon core such as the conductive yarn sold as Circuitex (RTM) by Noble Biomaterials Limited.

[0152] A first part of first conductive pathway 1408 is knit using the front needle bed. The back needle bed or both the front and back needle bed could also be used. The first part of first conductive pathway 1408 is knit using a fourth group of needle locations which are contained within the first group of needle locations and separate from the second group of needle locations. The first part of first conductive pathway 1408 is located outside of the pocket layer 1404.

[0153] The first part of first conductive pathways 1408 is knit using the same electrically conductive yarn as used for the first part of first connection region 1406 and is held on the same yarn carrier. The first part of first conductive pathway 1408 is electrically connected to the first part of first connection region 1406. The first part of first conductive pathway 1408 comprises one or a plurality of rows of knitted loops (courses). The first part of first conductive pathway 1408 forms part of the front layer of the fabric article.

[0154] A first electrode 1410 is knit by knitting electrically conductive yarn on the back needle bed. The electrically conductive yarn is the same as used for the first part of first conductive pathway 1408 and is held on the same yarn carrier. [0155] A plurality of rows of knitted loops (courses) are knitted to using the back needle bed only. The courses of knitted loops are partial length courses that are knitted using a fifth group of needle locations which are contained within the first group of needle locations and are separate from the second group of needle locations and the fourth group of needle locations.

[0156] Knitting a plurality of rows of knitted loops using the back needle bed only causes an excess of material to be formed and held on the back needle bed which enables the first electrode 1410 to adopt a raised three-dimensional profile. In addition to knitting electrically conductive yarn on the back needle bed, non-conductive yarn is also knitted on the front needle bed to form a second part of base layer. The knitted yarn comprises filler yarn which helps pack the space between the conductive yarn and the base layer to help maintain the shape of the three-dimensional first electrode 1410. An example knitting operation to form the first electrode 1410 is shown in FIG. 19A and FIG. 19B.

[0157] A second part of first conductive pathway 1412 is knit using the front needle bed. The back needle bed or both the front and back needle bed could also be used. The second part of the first conductive pathway 1412 is knit using the same electrically conductive yarn as used for the first electrode 1410 and is held on the same yarn carrier. The second part of first conductive pathway 1412 is knit in the same way as the first part of the first conductive pathway 1408. The second part of first conductive pathway 1412 is knit using the fourth group of needle locations.

[0158] A second part of first connection region 1414 is knit using the back needle bed. The second part of the first connection region 1414 is knit using the same electrically conductive yarn as used for the second part of first conductive pathway 1412 and is held on the same yarn carrier. The second part of first connection region 1414 is knit in the same way as the first part of first connection region 1406. The second part of first connection region 1414 is knit using the third group of needle locations.

[0159] A first part of second connection region 1416 is knit using the front needle bed. The first part of the second connection region 1416 is knit using electrically conductive yarn. The electrically conductive yarn is held on a different yarn carrier to the electrically conductive yarn used to knit the second part of the first connection region 1414. In this way, the first part of second connection region 1416 is not electrically connected to the second part of first connection region 1414. The first part of second connection region 1416 is knit using the same approach as used for the first part of first connection region 1406. The first part of second connection region 1416 is knit using a sixth group of needle locations contained within the second group of needle locations and separate from the third group of needle locations.

[0160] A first part of second conductive pathway 1418 is knit using the back needle bed. The back needle bed or both the front and back needle bed could also be used. The first part of second conductive pathway 1418 is knit using the same electrically conductive yarn as used for the first part of second connection region 1416 and is held on the same yarn carrier. The first part of second conductive pathway 1418 is knit using the same approach as used for the first part of first conductive pathway 1408. The first part of second conductive pathway 1418 is knit using a seventh group of needle locations contained within the first group of needle locations and separate from the second group of needle locations, fourth group of needle locations, and fifth group of needle locations.

[0161] A second electrode 1420 is knit by knitting electrically conductive yarn on the back needle bed. The electrically conductive yarn is the same as used for the first part of second conductive pathway 1418 and is held on the same yarn carrier. The second electrode 1420 is knit using the same approach as used for the first electrode 1410. The second electrode 1420 is knit using an eighth group of needle locations contained within the first group of needle locations and separate from the second group of needle locations, fourth group of needle locations, fifth group of needle locations, and seventh group of needle locations.

[0162] A second part of second conductive pathway 1424 is knit using the back needle bed. The back needle bed or both the front and back needle bed could also be used. The second part of the second conductive pathway 1424 is knit using the same electrically conductive yarn as used for the second electrode 1420 and is held on the same yarn carrier. The second part of second conductive pathway 1424 is knit using the same approach as used for the second part of first conductive pathway 1412. The second part of second conductive pathway 1424 is knit using the seventh group of needle locations.

[0163] A second part of second connection region 1422 is knit using the front needle bed. The second part of second connection region 1422 is knit using the same electrically conductive yarn as used for the second part of second conductive pathway 1424. The second part of second connection region 1422 is knit using the same approach as used for the second part of first connection region 1414. The second part of second connection region 1422 is knit using the sixth group of needle locations.

[0164] A third part of base layer 1426 is knitted using both the front needle bed and the back needle bed. The third part of base layer 1426 is knit using the same approach as used for the first part of base layer 1402. The third part of base layer 1426 is knit using the first group of needle locations.

[0165] FIG. 15A - FIG. 15D show an example fabric article 1502 formed as a result of the knitting sequence shown in FIG. 14.

[0166] FIG. 15A shows the fabric article 1502 when viewed from the front surface 1506. The fabric article 1502 comprises a base layer 1504, pocket layer 1404, a first conductive pathway 1508, and a second conductive pathway 1510.

[0167] The base layer 1504 is formed from the first part of base layer 1402, second part of base layer and third part of base layer 1426 described above in relation to FIG. 14. The base layer 1504 comprises first and second knit layers formed as a result of knitting yarn using both the first needle bed and the second needle bed.

[0168] The first conductive pathway 1508 is formed from the first part of first conductive pathway 1408 and second part of first conductive pathway 1412 described above in relation to FIG. 14. [0169] The second conductive pathway 1510 is formed from the first part of second conductive pathway 1418 and second part of second conductive pathway 1424 described above in relation to FIG. 14.

[0170] The pocket layer 1404 has a pair of side pocket openings 1518, 1520 and a pair of closed ends 1522, 1524. The side pocket openings 1518, 1520 enable the internal pocket space to be accessed. The pocket layer 1404 is connected to the base layer 1504 and overlaps the base layer 1504 in an overlapping region.

[0171] The first and second conductive pathways 1508, 1510 extend from the internal pocket space along the front surface 1506 of the base layer 1504. The conductive pathways 1508, 1510 extend along the width (course) direction of the fabric article.

[0172] FIG. 15B shows the fabric article 1502 when viewed from the back surface 1512 of the base layer 1504. The fabric article 1502 comprises first connection region 1514, a second connection region 1516, first electrode 1410, and second electrode 1420.

[0173] The first connection region 1514 is formed from the first part of first connection region 1406 and the second part of first connection region 1414 described above in relation to FIG. 14.

[0174] The second connection region 1516 is formed from the first part of second connection region 1416 and the second part of second connection region 1422 as described above in relation to FIG. 14.

[0175] The first and second connection regions 1514, 1516 are accessible from within the pocket space formed by the pocket layer 1404. The first and second connection regions 1514, 1516 are provided in the overlapping region.

[0176] The first connection region 1514 is electrically connected to the first electrode 1410 by the first conductive pathway 1508. The first connection region 1514, first conductive pathway 1508, and first electrode 1410 form a first sensing unit of the fabric article 1502.

[0177] The second connection region 1516 is electrically connected to the second electrode 1420 by the second conductive pathway 1510. The second connection region 1516, second conductive pathway 1510, and second electrode 1420 form a second sensing unit of the fabric article 1502.

[0178] FIG. 15C shows the fabric article 1502 when viewed from the front surface 1506. The pocket layer 1404 is removed to show the internal pocket space. As the internal pocket space only comprises a single fabric layer, the first connection region 1514 and the second connection region 1516 are accessible from the internal pocket space.

[0179] FIG. 15D shows the fabric article 1502 when viewed from the side. The pocket layer 1404 extends away from the front surface 1506 of the base layer 1504. The first electrode 1410 and the second electrode 1420 extend away from the back surface 1512 of the base layer 1504 to form three-dimensional profiles.

[0180] The side pocket openings 1518, 1520 are sized to accommodate an electronics module. The electronics module comprises an interface that couples with the first connection region 1514 and the second connection region 1516 when positioned within the pocket. This brings the electronics module into communication with the first electrode 1410 and the second electrode 1420 and enables the electronics module to received measurement signals from the first electrode 1410 and the second electrode 1420 and also apply signals to the first electrode 1410 and the second electrode 1420. The electronics module comprises a processor that processes the received measurement signals and a communicator that is able to communicate sensor data to an external device such as a mobile phone. The communicator is typically a wireless communicator such as a Bluetooth (RTM) communicator.

[0181] The first electrode 1410 and the second electrode 1420 may function as sensors for monitoring activity at a body surface of a wearer of the fabric article. The electrodes may be arranged to measure one or more biosignals of a user wearing the fabric article. Here, “biosignal” may refer to any signal in a living being that can be measured and monitored. The electrodes are generally for performing bioelectrical or bioimpedance measurements. Bioelectrical measurements include electrocardiograms (ECG), electrogastrograms (EGG), electroencephalograms (EEG), and electromyography (EMG). Bioimpedance measurements include plethysmography (e.g., for respiration), body composition (e.g., hydration, fat, etc.), and electroimpedance tomography (EIT).

[0182] The first electrode 1410 and the second electrode 1420 may alternatively or additionally function to apply signals to the body surface such as for therapy or treatment applications.

[0183] FIG. 16 shows an example knitting notation diagram for forming the first part of base layer 1402 and/or the third part of base layer 1426 shown in FIG. 14. The knitting notation diagram shows a sequence of steps performed by the knitting machine to form the part of the base layer. Each of the sequence of steps shows knitting operations performed by the front needle bed and the back needle bed of the knitting machine. The knitting notation diagrams are read from bottom to top.

[0184] It will be appreciated that FIG. 16 shows just a simplified example of the knitting operation. The number of courses and the number of stitches per course (the number of needle locations) may vary.

[0185] Steps 1602, 1604, 1606, 1608, 1610, 1612, 1614, 1616 comprise knitting, using the first needle bed and the second needle bed, a plurality of rows (courses) of non-conductive yarn. The plurality of rows of non-conductive yarn comprise rows of knitted loops which are knitted in operations 1602, 1604, 1608, 1610, 1614, 1616. The rows of knitted loops are interspersed with rows comprising tuck stitches which are knitted in operations 1606, 1612. The rows of tuck stitches are sandwiched between pairs of rows of knitted loops. For example, the row of tuck stitches knitted in step 1606 is sandwiched between the rows of knitted loops knitted in steps 1604 and 1608.

[0186] The row of tuck stitches knitted in step 1606 comprises a repeated sequence of tuck stitches. In particular, a sequence of a tuck stitch on the first needle bed followed by a tuck stitch on the second needle bed is repeated along the course.

[0187] The row of tuck stitches knitted in step 1612 comprises the reverse of the sequence used in operation 1606. This means that a sequence of a tuck stitch on the second needle bed followed by a tuck stitch on the first needle bed is repeated along the course.

[0188] Interspersing rows of tuck stitches between tows of knitted loops adds compression to the base layer. This helps urge the first electrode and the second electrode of the fabric article against a skin surface of the wearer when the fabric article is worn. This helps ensure good signal contact between the wearer and the first electrode and the second electrode.

[0189] The rows of knitted loops and the rows of tuck stitches may be knitted using the same yarn held on the same yarn carrier. Alternatively, they may be knitted with different yarns held on different yarn carriers.

[0190] FIG. 17 shows an example knitting notation diagram for forming the first part of base layer 1402 and/or the third part of base layer 1426 shown in FIG. 14. The knitting notation diagram shows a sequence of steps performed by the knitting machine to form the part of the base layer. Each of the sequence of steps shows knitting operations performed by the front needle bed and the back needle bed of the knitting machine. The knitting notation diagrams are read from bottom to top.

[0191] Steps 1702, 1704, 1706, 1708, 1710, 1712, 1714, 1716 comprise knitting using the first needle bed and the second needle bed, a plurality of rows (courses) of non-conductive yarn. The plurality of rows of non-conductive yarn comprise rows of knitted loops which are knitted in operations 1702, 1704, 1708, 1710, 1714, 1716. The rows of knitted loops are interspersed with rows comprising tuck stitches which are knitted in operations 1706, 1712. The rows of tuck stitches are sandwiched between pairs of rows of knitted loops. For example, the row of tuck stitches knitted in 1706 is sandwiched between the rows of knitted loops knitted in 1704 and 1708.

[0192] The row of tuck stitches knitted in operation 1706 comprises a repeated sequence of tuck stitches. In particular, a sequence of a tuck stitch on the first needle bed followed by a tuck stitch on the second needle bed is repeated along the course. The tuck stitches are separated by a float stitch.

[0193] The row of tuck stitches knitted in operation 1712 comprises the reverse of the sequence used in operation 1706. This means that a sequence of a tuck stitch on the second needle bed followed by a tuck stitch on the first needle bed is repeated along the course. The tuck stitches are separated by a float stitch.

[0194] The row of knitted loops 1702, 1704, 1708, 1710, 1714, 1716 are knitted in a tubular jacquard fashion. The rows are knitted in pairs (1702, 1704), (1708, 1710), (1714, 1716). Each pair comprises a first row 1702, 1708, 1714 knitted using a first yarn held on a first yarn carrier and a second row 1704, 1710, 1716 knitted using a second yarn held on a second yarn carrier. The first yarn and the second yarn may be different types of yarn and may have different colours or other different properties.

[0195] During the knitting of the first rows 1702, 1708, 1714 in the pairs, the first yarn crosses between the first needle bed and the second needle bed at one or more needle locations. This means that knitted loops are selectively formed using both the front needle bed and the second needle bed.

[0196] During the knitting of the second rows 1704, 1710, 1716 in the pairs, the second yarn crosses between the first needle bed and the second needle bed at the same one or more locations. This means that knitted loops are selectively formed using both the front needle bed and the second needle bed.

[0197] Having the first yarn and the second yarn cross between the first and second needle beds introduces colour variations (or other variations in properties) between the front surface and the back surface of the base layer.

[0198] For example, the first yarn may be white and the second yarn may be black. Switching the first yarn and the second yarn between the front and back needle beds enables select parts of the front surface and back surface of the base layer to be black and other parts to be white. It will be appreciated that the back surface will have the inverse of the pattern on the front surface such that black regions on the front surface will be white on the back surface. This is because at needle locations where the first yarn crosses from the front needle bed to the back needle bed, the second yarn crosses from the back needle bed to the front needle bed.

[0199] The use of different coloured yarns can be used to produce desired aesthetic effects for the wearable article. In addition, the use of different coloured yarns can be used to form one or more information elements for the wearable article. An information element may provide information about the fabric article. The information could include an owner of the fabric article, a length of the fabric article, a manufacturer of the fabric article or any other form of information as desired by the skilled person. The information element in this example is in the form of text but could equally be an image or a machine-readable code.

[0200] Beneficially, the information element is formed as a result of the knitting of the base layer using the first and second yarns. This means that the information element is integrally formed as part of the knitting process. A separate process such a printing, transferring, or stitching is therefore not required to form the information element. This simplifies the manufacturing process for forming the fabric article.

[0201] FIG. 18 shows an example knitting notation diagram for forming the first part of base layer 1402 and/or the third part of base layer 1426 shown in FIG. 14. The knitting notation diagram shows a sequence of steps performed by the knitting machine to form the part of the base layer. Each of the sequence of steps shows knitting operations performed by the front needle bed and the back needle bed of the knitting machine. The knitting notation diagrams are read from bottom to top.

[0202] Steps 1802, 1804, 1806, 1808, 1810 comprise knitting using the first needle bed and the second needle bed, a plurality of courses of non-conductive yarn. The plurality of courses of non- conductive yarn comprise rows (courses) of knitted loops which are knitted in operations 1802, 1804, 1808, 1810 and which are interspersed with rows comprising tuck stitches which are knitted in operations 1806. The rows of tuck stitches are sandwiched between pairs of rows of knitted loops. For example, the row knitted of tuck stitches knitted in 1806 is sandwiched between the row of knitted loops knitted in 1804 and 1808. [0203] The row of tuck stitches knitted in operation 1806 comprises a repeated sequence of tuck stitches. In particular, a tuck stitch on the first needle bed and a tuck stitch on the second needle bed are simultaneously knitted. The tuck stitches are separated by a float stitch.

[0204] The rows of knitted loops 1802, 1804, 1808, 1810 are knitted in a tubular jacquard fashion. The rows are knitted in pairs (1802, 1804), (1808, 1810). Each pair comprises a first row 1802, 1808 knitted using a first yarn held on a first yarn carrier and a second row 1804, 1810 knitted using a second yarn held on a second yarn carrier. The first yarn and the second yarn may be different types of yarn and may have different colours or other different properties.

[0205] During the knitting of the first rows 1802, 1808 in the pairs, the first yarn crosses between the first needle bed and the second needle bed at one or more needle locations. This means that knitted loops are selectively formed using both the front needle bed and the second needle bed.

[0206] During the knitting of the second rows 1804, 1810 in the pairs, the second yarn crosses between the first needle bed and the second needle bed at the same one or more locations. This means that knitted loops are selectively formed using both the front needle bed and the second needle bed.

[0207] FIG. 19A and FIG. 19B show an example knitting notation diagram for forming the first electrode 1410 and/or second electrode 1420 shown in FIG. 14. The knitting notation diagram shows a sequence of steps performed by the knitting machine to form the sensor. Each of the sequence of steps shows knitting operations performed by the front needle bed and the back needle bed of the knitting machine. The knitting notation diagrams are read from bottom to top starting at FIG. 19A.

[0208] Steps 1902 and 1904 show knitting operations used to form the last two rows of knitted courses of the first part of base layer 1402 (FIG. 14) prior to the knitting of the sensor. The subsequently knitted electrically conductive yarn is attached to the course knitted in 1904. As described above, knitting the first part of base layer 1402 comprises knitting, using the front needle bed and back needle bed, a plurality of courses of non-conductive yarn. The remainder of the first part of base layer 1402 may have the same structure as described in FIG. 16, FIG. 17 or FIG. 18 for example or may have a different knit structure.

[0209] In this example, step 1902 comprises forming knitted loops on the front needle bed and tuck stitches on the back needle bed. Step 1904 comprises forming tuck stitches on the front needle and knitted loops on the back needle bed. The knitting sequence for step 1904 is therefore the reverse of the knitting sequence for step 1902. This means that tuck-rib stitches are knitted in a two-course repeat manner. These alternating sequences of tuck-rib stitches are often referred to as full-cardigan stitches.

[0210] It is not required to knit the first part of the base layer using full-cardigan stitches and other stitches sequences are possible such as half-cardigan stitches, double-knit, interlock, single-knit, links or ribbed. Moreover, the first part of the base layer is not required to only have one type of knit sequence. The majority of the first part of base layer 1402 may be knit using any knit sequence such as those shown in FIG. 16, FIG. 17, and FIG. 18 while the knit courses preceding the conductive yarn may be knit using the full-cardigan stitches shown in this figure.

[0211] Using tuck-rib stitches at least for the knit courses preceding the conductive yarn is advantageous as it enables the base layer to accommodate conductive yarns having a greater thickness.

[0212] The tuck stitches cause the rib wales to gape apart so that the body width spreads outwards to a greater extent than the rib border this results in larger gaps between the stitches. The tuck stitches are not easily visible when viewing the front or back surface of the base layer. This results in the base layer having larger gaps between stitches as compared to other knitting techniques such as just using knitted loops on both needle beds or an interlock knitting technique. These larger gaps enable the base layer to accommodate thicker conductive yarn. Thicker conductive yarn is advantageous as it is less likely to break and is more resistant to washing. Fabric articles with thicker conductive yarn can typically be washed a greater number of times without the measured impedance increasing beyond and acceptable value.

[0213] Yarn thickness may be measured using its yarn count. Yarn count is a measure of the total length per weight of yarn. The yarn count measures include Cotton Count (cc) which gives a measure of the number of 840 yard units in a pound of yarn, Worsted Count (wc) which gives a measure of the number of 560 yard units in a pound of yarn, and Numero Metric Count (nm) which gives a measure of the number of 1000 metre units in a kilogram of yarn.

[0214] Yarn counts are typically represented in the form X/Y, where X is the yarn count for a single ply of yarn and Y is the number of piles that make up the yarn. The number X is divided by Y to give the final yarn count.

[0215] For example, a yarn may have a yarn count of 30/2 nm which means that each ply has a yarn count of 30 and that there are two plies that make up the yarn. The final yarn count is 15 nm which means that there are 15000 metres of yarn per kilogram.

[0216] Another yarn may have a yarn count of 20/2 nm which means that each ply has a yarn count of 20 and that there are two plies that make up the yarn. The final yarn count is 10 nm which means that there are 10000 metres of yarn per kilogram.

[0217] A yarn with a lower yarn count in nm is therefore heavier per unit length and thicker than a yarn with a higher yarn count.

[0218] In some examples, a yarn with a yarn count of 15nm or higher is thin enough that it can fit through the gaps in a base component regardless of the knitting technique used to manufacture the base component, e.g. knit using both needle beds simultaneously or using an interlock technique. However, yarns with yarn counts lower than this value may be more challenging to fit through the gaps between stitches in the base component. This can increase the complexity of the knitting process and reduce the appearance and performance of the resultantly formed fabric article.

[0219] Advantageously, knitting the base layer using cardigan stitches results in larger gaps between the knitted stitches which allows for conductive yarns with a yarn count of less than 15nm to be intermeshed with the base component. [0220] Moreover, using cardigan stitches result in a base layer with a reduced weight as cardigan stitches use less yarn and are lighter than other knit structures. This enables a wider base layer to be knitted for the same weight/amount of yarn. Moreover, the knitting process for forming a base layer using cardigan stitches is faster than other knitting techniques such as interlock which enables the fabric article 100 to be manufactured more quickly. Therefore, forming the base component using cardigan stitches reduces the time required to knit the fabric article.

[0221] In preferred examples, the courses preceding the conductive yarn are knit using cardigan stitches and the conductive yarn has a yarn count of less than 15nm. The yarn count may be less than 14nm, less than 13nm, less than 12nm, less than 11 nm. The yarn count may be greater than 5nm, greater than 6nm, greater than 7nm, greater than 8nm, or greater than 9nm. The yarn count may be between 8nm and 12nm and is preferably 10 nm (e.g. a yarn with a yarn count of 20/2 nm). The conductive yarn in this example is preferably a stainless-steel yarn.

[0222] Steps 1906, 1908, 1910 comprise knitting, using the back needle bed, a plurality of courses of electrically conductive yarn to form a first part of a electrode. The plurality of courses of conductive yarn comprise knitted loops. A first of the plurality of courses is connected to the first part of the base layer and a last of the plurality of courses is held on the back needle bed.

[0223] Steps 1912, 1914, 1916, 1918, 1920, 1922, 1924, 1926, 1928, 1930, 1932, 1934, 1936, 1938, 1940, 1942, 1944, 1946 comprise knitting, using the front needle bed, a plurality of courses of non-conductive yarn and a plurality of courses of filler yarn to form the second part of base layer. The courses of filler yarn are interspersed between courses of non-conductive yarn such that each course of filler yarn is provided between two courses of non-conductive yarn.

[0224] The knitting of the plurality of courses of non-conductive yarn is shown in steps 1912,

1914, 1916, 1920, 1924, 1928, 1932, 1936, 1940, 1942, 1944, 1946. The knitting of the plurality of courses of filler yarn is shown in steps 1918, 1922, 1926, 1930, 1934, 1938. The course 1918 of filler yarn is provided between courses 1916 and 1920 of non-conductive yarn. The course 1922 of filler yarn is provided between courses 1920 and 1924 of non-conductive yarn. The course 1926 of filler yarn is provided between courses 1924 and 1928 of non-conductive yarn. The course 1930 of filler yarn is provided between courses 1928 and 1932 of non-conductive yarn. The course 1934 of filler yarn is provided between courses 1932 and 1936 of non-conductive yarn. The course 1938 of filler yarn is provided between courses 1936 and 1938. No two courses of filler yarn are provided immediately adjacent one another.

[0225] Each of the courses of filler yarn comprise tuck stitches separated by at least one float stitch. In this example, the tuck stitches are separated by three float stitches. This means that for every tuck stitch there is three float stitches.

[0226] Tuck knitting operations result in the formation of an extra stitch behind an existing stitch. The extra stitch is not visible from the outside surface of the fabric article. The tuck stitch is used to layer-in the filler yarn behind the conductive regions so that it is not visible from the outside of the fabric article. [0227] Knitting the plurality of courses of conductive yarn on the back needle bed causes the conductive yarn to gather on the back needle bed. As no knitting is performed on the front needle bed at the same time, the knit structure is unbalanced. This is desired as it enables the electrode to adopt a raised three-dimensional profile that extends away from the base layer. To enable the electrode to maintain its three-dimensional profile, the filler yarn is provided. The filler yarn acts to fill the gap formed between the base layer and the electrode.

[0228] The filler yarn is a thick, bulky, yarn (relative to the non-conductive yarn used for the remainder of the base layer) which can be challenging to knit with consistently on the knitting machine. For example, while a single knitted course of filler yarn could be knitted comprising a tuck stitch at every (or most) needle location, the thickness of the filler yarn could make this difficult to implement as it would be challenging to effectively cram all of this filler yarn into a single previously knitted course of non-conductive yarn. The resultant knit structure could be unstable or the knitting machine may even jam when attempting to knit such an arrangement. To overcome this problem, the filler yarn is knitted in a plurality of courses which are separated by courses of non-conductive yarn. This provides extra material to accommodate filler yarn. Moreover, in each course of filler yarn, float stitches are included to reduce the amount of filler yarn that is knitted in a single course. This means that rather than knitting all of the filler yarn in a single course, the same amount of filler yarn is knitted using multiple courses where each course only introduces a portion of the filler yarn. In this way, the desired effect of providing filler yarn to bulk out the electrode is still achieved but the sensor is easier to knit and more stable.

[0229] The filler yarn in this example is an expanding yarn. The expanding yarn may refer to a yarn that expands under the application of an external stimulus such as heat, pressure or steam. Preferably the yarn expands under the application of steam. The expanding yarn may comprise a polyester material and may be a polyester filament yarn. The expanding yarn used in this example is a Newlife ™ polyester filament yarn manufactured by Sinterama S.p.A.

[0230] Beneficially, the use of an expanding yarn means that after the fabric article is constructed, steam (for example) may be applied to cause the yarn to expand and bulk out the shape of the sensor and provide further stability.

[0231] As the expanding yarn expands to fill the space between the sensor and the base layer, the space between the sensor and the base layer does not need to be densely packed with filler material during the knitting operation. Less yarn is required than if a non-expanding filler material were used. For example, a single strand of expanding yarn may provide the necessary support and stability function when the steam (for example) is applied.

[0232] The filler yarn provides a stabilising function for the sensor in order to reduce noise and other electronic artefacts. The filer yarn urges the profile of the sensor out from the base layer and increases the quality, consistency and area of contact for the sensor against the skin surface. This is provided without requiring an increase in the amount of compression applied to the skin surface by the fabric article. Moreover, as the expanding yarn is integrally knit with the remainder of the fabric article, this simplifies the manufacturing process and avoids the need to separately insert filler material after the continuous body of fabric is formed. [0233] The filler yarn is knit using front needle bed knitting in regions where the conductive yarn is knit using the back needle bed. This is performed so as to anchor the filler yarn on the base layer rather than the sensor. This is particularly desirable when an expanding yarn is used as a filler yarn as it helps ensure that the expanding yarn pushes against and urges the sensor away from the base layer to form the desired three-dimensional shapes.

[0234] In preferred examples, the extra courses of non-conductive yarn knit to accommodate the multiple filler yarn courses also include float stitches as shown in steps 1918, 1922, 1926, 1930, 1934, and 1938. This helps to reduce the total amount of extra non-conductive yarn knit to accommodate the additional courses of filler yarn. Ideally, the number of float stitches per tuck stitch is greater than the number of float stitches per knitted loop.

[0235] The courses of non-conductive yarn and courses of filler yarn can be considered as forming different pairs of courses (1918, 1920), (1922, 1924), (1926, 1928), (1930, 1932), (1934, 1936), (1938, 1940) where each pair comprises a first course of filler yarn comprising tuck stitches separated by float stitches and a second course of non-conductive yarn comprising knitted loops separated by float stitches.

[0236] In each pair, the needles used to form the tuck stitches in the first course are also used to form the knitted loops in the second course. In adjacent pairs, different needles are used to form the tuck stitches and knitted loops. For example, in step 1920, odd numbered needles are used to form the knitted loops, while in step 1924, even numbered needles are used to form the knitted loops. Using different needles in different pairs helps spread the filler yarn across the width (course direction) of the electrode.

[0237] As explained above, some of the plurality of courses of non-conductive yarn comprise knitted loops separated by one or more float stitches as shown in steps 1914, 1916, 1920, 1924, 1928, 1932, 1936, 1940, 1942, 1944. The first and last course of non-conductive yarn shown in steps 1912 and 1946 comprise a full sequence of knitted loops without float stitches.

[0238] The filler yarn is not required to be interspersed between every course of non-conductive yarn. In this example, no filler yarn is provided between courses 1912 and 1914, 1914 and 1916, 1940 and 1920, 1942 and 1944 or 1944 and 1946.

[0239] Steps 1948, 1950, 1952, 1954 comprise knitting, using the back needle bed, a plurality of courses of electrically conductive yarn to form a second part of the electrode. The plurality of courses of conductive yarn comprise knitted loops. A first of the plurality of courses is connected to the last of the plurality of courses of the first part of the electrode and a last of the plurality of courses is held on the second needle bed.

[0240] Step 1956 comprises knitting, using the first needle bed and the second needle bed, at least one course of non-conductive yarn to form the third part of the base layer. The third part of base layer is connected to the last of the plurality of courses of the second part of the base layer and the last of the plurality of courses of conductive yarn knit using the second needle bed. In this example, the at least one course of non-conductive yarn comprises a course of tuck stitches on the front needle bed and knitted loops on the back needle bed. The third part of base layer may comprise additional knit courses such as additional full-cardigan stitches and may also comprise additional knit sequences such as those shown in FIG. 16, FIG. 17 and FIG. 18.

[0241] FIG. 20A, FIG. 20B and FIG. 20C show an example fabric article 2002 formed as a result of the knitting operations shown in FIG. 19A and FIG. 19B. The fabric article 2002 may form the first electrode 1410 or the second electrode 1420 of FIG. 14 but is not required to be or be part of the fabric article formed in FIG. 14. The fabric article 2002 may be self-contained or may be incorporated into a different fabric article. For example, the fabric article 2002 may be formed as part of a fabric article comprising a single sensing unit. That is, a single sensor, electrically conductive pathway and connection region provided on a base layer. Multiple sensing units are not required be knit with the fabric article in all examples. Moreover, the pocket layer is not required to be knit in all examples. A pocket may be otherwise attached to the fabric article such as by bonding or stitching. A pocket may also not be required as another mechanism for releasably attaching the electronics module to the fabric article may be provided. Other forms of attachment mechanisms include the use of mechanical fasteners such as studs and poppers or hook-and-loop fasteners. Other attachment mechanisms such as those using magnets may also be provided.

[0242] FIG. 20A shows the fabric article 2002 viewed from below. FIG. 20B shows the fabric article 2002 viewed from the side. FIG. 20C shows the fabric article 2002 viewed from above.

[0243] The fabric article 2002 comprises a base layer 2004.

[0244] A first part of base layer 2006 is formed from at least one course of non-conductive yarn. The first part of base layer 2006 is formed as a result of the knitting operations 1902 and 1904 shown in FIG. 19A. As the first part of base layer 2006 is knit using both the front and back needle beds, the first part of base layer 2006 has a double layer construction and comprises first and second fabric layers.

[0245] A second part of base layer 2012 is formed from a plurality of courses of non-conductive yarn interspersed with courses of filler yarn such that each course of filler yarn is provided between two courses of non-conductive yarn. The second part of base layer 2012 is formed as a result of the knitting operations 1912, 1914, 1916, 1918, 1920, 1922, 1924, 1926, 1928, 1930, 1932, 1934, 1936, 1938, 1940, 1942, 1944, 1946 in FIG. 19A and FIG. 19B. The knitted courses are formed using the front needle bed only so that the second part of base layer 2012 only comprises a first fabric layer. The first fabric layer is connected to the first fabric layer of the first part of base layer 2006.

[0246] A third part of base layer 2010 is formed from at least one course of non-conductive yarn. The third part of base layer 2010 is formed as a result of the knitting operation 1956 shown in FIG. 19B. As the third part of base layer 2010 is knit using both the front and back needle beds, the third part of base layer 2010 has a double layer construction and comprises first and second fabric layers. The first fabric layer is connected to the first fabric layer of the second part of base layer 2012.

[0247] The fabric article 2002 further comprises an electrode 2008 formed from a plurality of courses of electrically conductive yarn. The electrode 2008 is formed as a result of the knitting operations 1906, 1908, 1910, 1948, 1950, 1952, 1954 shown in FIG. 19A and FIG. 19B. The electrode 2008 is formed using the back needle bed only so comprises a single fabric layer. This first fabric layer of the electrode 2008 is connected to the second fabric layer of the first part of base layer 2006 and the second fabric layer of the third part of base layer 2010.

[0248] As the second part of base layer 2012 is formed using the front needle bed only it is not visible from the top surface of the fabric article 2002 as shown in FIG. 20A as it is covered by the electrode 2008. The second part of base layer 2012 is visible from the bottom surface of the fabric article 2002 as shown in FIG. 20C.

[0249] As the electrode 2008 is formed using the back needle bed only, it is visible from the bottom surface of the fabric article 2002 as shown in FIG. 20A, but is not visible from the top surface as shown in FIG. 20C as it is covered by the second part of base layer 2012. The electrode 2008 forms a raised, three-dimensional region that extends away from a surface of the base layer as shown in FIG. 20B.

[0250] FIG. 21 A and FIG. 21 B show a sequence of knitting steps used to form an example of pocket layer 1404, first part of first connection region 1406, second part of first connection region 1414, first part of second connection region 1416, and second part of second connection region 1422 of FIG. 14.

[0251] The knitting notation diagram shows a sequence of steps performed by the knitting machine. Each of the sequence of steps shows knitting operations performed by the front needle bed and the back needle bed of the knitting machine. The knitting notation diagrams are read from bottom to top starting at FIG. 21 A. The knitting diagram shows knitting operations that occur within the second group of needle locations referenced in FIG. 14 which are contained within the first group of needle locations used to form the fabric article of FIG. 14.

[0252] Step 2102 comprises knitting a course of first part of base layer 1402 (FIG. 14) preceding the pocket layer 1404. This comprises knitting non-conductive yarn using both the front needle bed and the back needle simultaneously to form a double-knit course.

[0253] Step 2012 shows the knitting operation used to form the last row of knitted stitches of the first part of base layer 1402 (FIG. 14) prior to the knitting of the pocket layer. As described above, knitting the first part of base layer 1402 comprises knitting, using the front needle bed and back needle bed, a plurality of courses of non-conductive yarn. The remainder of the first part of base layer 1402 may have the same structure as described in FIG. 16, FIG. 17 or FIG. 18 for example or may have a different knit structure

[0254] Step 2104 comprises transferring a plurality of stitches (six in this example) from the back needle bed to the front needle bed. The transferring of stitches occurs at a small number of needle locations contained within the second group of needle locations that form the pocket layer. The needle locations are (approximately) centrally located within the group of needle locations that form the pocket layer.

[0255] This enables an opening to be formed in the back layer of the base layer of the fabric article. The opening is provided between the first connection region and the second connection region and helps to electrically isolate the first connection region from the second connection region. In addition, the opening means that there is no base layer material between the first connection region and the second connection region which reduces the likelihood of moisture forming a bridge between the first connection region and the second connection region.

[0256] Step 2106 and 2108 comprise knitting a plurality of rows of stitches of non-conductive yarn using the front needle bed using the second group of needle locations. This forms the pocket layer. Only two courses are shown in FIG. 21A but it will be appreciated that additional rows may be knitted to increase the size of the pocket layer. As the front needle bed is used to knit the rows, this causes an unbalanced knit structure to be formed on the front needle bed.

[0257] Steps 2110, 2112, 2114, 2116 comprise knitting a plurality of rows of stitches of electrically conductive yarn to form the first connection region using the third group of needle locations (FIG. 14). Steps 2110 and 2112 form the first part of first connection region 1406. Steps 2114 and 2116 form the second part of first connection region 1414. It will be appreciated that between steps 2112 and 2114, the first electrically conductive pathway and first electrode may be knit as described above in relation to FIG. 14.

[0258] Step 2118 comprises knitting a course of non-conductive yarn using the back needle bed. The course extends across the width of the pocket space. In the region where yarn has previously been transferred form the back needle bed to the front needle bed, there are no existing knitted loops held on the back needle bed so the stitches in this region are in effect tuck stitches. This step adds material to the base layer behind the pocket layer.

[0259] Step 2120, 2122, 2124, 2126 comprise knitting a plurality of rows of stitches of electrically conductive yarn to form the second connection region using the sixth group of needle locations. Steps 2120 and 2122 form the first part of second connection region 1416. Steps 2124 and 2126 form the second part of second connection region 1422. It will be appreciated that between steps 2122 and 2124, the second electrically conductive pathway and second electrode may be knit as described above in relation to FIG. 14.

[0260] Step 2128 comprises knitting a course of non-conductive yarn using the front needle bed.

[0261] Step 2130 comprises knitting a course comprising knitted loops on the back needle bed and tuck stitches on the front needle bed. For the needle locations where yarn was previously transferred to the front needle bed in step 2104, the stitches formed comprise an alternating sequence of knitted loops formed on the front and back needle beds. This helps close up the opening formed as a result of the stitch transfer in step 2104.

[0262] Step 2132 comprises knitting a course comprising knitted loops on the front needle bed. For the needle locations where yarn was previously transferred to the front needle bed in step 2104, the stitches formed comprise knitted loops on the back needle bed separated by float stitches. This helps close up the opening formed as a result of the stitch transfer in step 2104.

[0263] Step 2134 comprises knitting a course comprising knitted loops on the front needle bed.

[0264] The fabric articles described above may be attached to a wearable article such as a cheststrap or other form of garment such as a shirt, t-shirt, tank or bra. [0265] The fabric articles may be integrally knit with the wearable article. Such as by integrally knitting a garment comprising the fabric article.

[0266] The present disclosure is not limited to any particular dimension of the electrodes, conductive pathways, or connection regions.

[0267] At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others.

[0268] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0269] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[0270] The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

32 CLAIMS

1. A method of knitting a fabric article using a knitting machine comprising a first needle bed and a second needle bed, the method comprising: knitting, using the first needle bed and the second needle bed, a plurality of courses of non- conductive yarn to form a first part of a base layer, the plurality of courses of non-conductive yarn comprising courses of knitted loops interspersed with courses comprising tuck stitches, a first of the courses of tuck stitches comprising a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed using the first needle bed and a tuck stitch formed using the second needle bed, a second of the courses of tuck stitches comprising the reverse of the sequence used for the first of the courses of tuck stitches; and knitting, using the second needle bed, electrically conductive yarn to form an electrode connected to the first part of the base layer.

2. The method of claim 1 , wherein the sequence of tuck stitches comprises one or more float stitches between the tuck stitch formed using the first needle bed and the tuck stitch formed using the second needle bed.

3. The method of claim 1 or claim 2, wherein the sequence of tuck stitches comprises simultaneously forming tuck stitches using the first needle bed and the second needle bed.

4. The method of any preceding claim, wherein knitting the plurality of courses of non-conductive yarn comprises knitting a repeating sequence of courses, the repeating sequence comprising: knitting at least one course of non-conductive yarn comprising knitted loops; knitting a course of tuck stitches.

5. The method of claim 4, wherein knitting the at least one course of non-conductive yarn comprises: knitting a first course of non-conductive yarn comprising knitted loops using a first knitting sequence; and knitting a second course of non-conductive yarn comprising knitted loops using a second knitting sequence, wherein the second knitting sequence is the reverse of the first knitting sequence such that stitches performed on the first needle bed in the first course are performed on the second needle bed in the second course, and stitches performed on the second needle bed in the second course are performed on the first needle bed in the first course.

6. The method of claim 5, wherein knitting the first course uses a first yarn and knitting the second course uses a second yarn.

7. The method of claim 6, wherein, in the first course, the first yarn crosses between the first needle bed and the second needle bed at one or more needle locations, and wherein, in the second course, the second yarn crosses between the first needle bed and the second needle bed at the one or more needle locations. 33

8. The method of claim 5 or claim 6, wherein knitting the first course comprises forming knitted loops using the first needle bed, and knitting the second course comprises forming knitted loops using the second needle bed.

9. The method of claim 5 or claim 6, wherein knitting the first courses comprising forming knitted loops using the first needle bed and forming tuck stitches using the second needle bed, and knitting the second course comprises forming tuck stitches using the first needle bed and knitted loops using the second needle bed.

10. The method of any preceding claim, further comprising: knitting, using the first needle bed and the second needle bed, a plurality of courses of non- conductive yarn to form a further part of the base layer connected to the first part of the base layer and the electrode, the plurality of courses of non-conductive yarn comprising courses of knitted loops interspersed with courses comprising tuck stitches, a first of the courses of tuck stitches comprising a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed using the first needle bed and a tuck stitch formed using the second needle bed, a second of the courses of tuck stitches comprising the reverse of the sequence used for the first of the courses of tuck stitches.

11 . The method of any preceding claim, further comprising: knitting, using the first needle bed or the second needle bed, electrically conductive yarn to form a connection region and a conductive pathway that extends from the electrode to the connection region and electrically connects the electrode to the connection region.

12. The method of any preceding claim, wherein knitting electrically conductive yarn to form the electrode comprises knitting, using the second needle bed, a plurality of rows of electrically conductive yarn such that the electrode forms a three-dimensional surface that extends away from the first part of the base layer.

13. A computer program comprising instructions recorded thereon which, when executed by a computer associated with a knitting machine, are operable to cause the computer to control the knitting machine to perform the method as claimed in any preceding claim.

14. A knitted fabric article comprising: a base layer comprising a first knit layer and a second knit layer, the base layer comprising a plurality of courses of non-conductive yarn, the plurality of courses of non-conductive yarn comprising courses of knitted loops interspersed with courses comprising tuck stitches, a first of the courses of tuck stitches comprising a repeated sequence of tuck stitches, the repeated sequence comprises a tuck stitch formed on the first knit layer and a tuck stitch formed on the second knit layer, a second of the courses of tuck stitches comprising the reverse of the sequence used for the first of the courses of tuck stitches; and an electrode formed from electrically conductive yarn and connected to the base layer.

15. The knitted fabric article of claim 14, further comprising a connection region and a conductive pathway formed from electrically conductive yarn, wherein the conductive pathway extends from the electrode to the connection region and electrically connects the electrode to the connection region.