LV14889B - Resistive textile material for control systems and a method of use thereof - Google Patents

Abstract

Present invention relates to production of “smart textiles” integrated into a garment for health monitoring. Knitted resistive fabric produced from a conductive resistive and non-conductive isolating yarns and non-conductive elastomeric yarns is offered. Elastomeric yarn is a base yarn and is knitted in the whole fabric, but isolating and resistive yarns (functional yarns) are knitted separately from each other, but together with the base yarn in specific sequence. Knitted resistive fabric is applicable to control deformations of body parts, joint motions, respiration, ECG and other vital parameters.

Description

DESCRIPTION OF THE INVENTION

The invention relates to the manufacture of knitted fabrics, and more particularly to a fabric used in "smart textile" human health monitoring systems, including built-in garments.

Control systems that incorporate elastic sensing elements made of conductive textile fabric are increasingly used in medicine and in the daily monitoring of human health, timely diagnosis of advanced illnesses, rehabilitation of diseases associated with movement disorders, and more. It is based on the ability to integrate these systems, for example, directly into clothing. These control systems are based on a textile fabric which is knitted with electrically conductive filaments and which is capable of changing its electrical properties during fabric deformation. Therefore, the development of technologies for the production of knitted fabrics which are easy to manufacture and have a high electrical susceptibility to deformation is very urgent.

Knitted fabrics are known to be knitted from conductive filaments with silver plating and dielectric elastomeric filaments [1]. The rows of elastomeric filaments are inserted between the rows of conductive filaments. The rows of conductive filaments are knitted with jacquard or press braided so that all of these rows are permanently electrically connected to each other and thus form a conductive network. This network is used for protection against electromagnetic radiation, as an antibacterial coating for protection against infections, etc. Such fabrics have not been used in control systems.

Knitted fabrics [2] which are knitted with electrically conductive elastomers and non-elastomeric filaments and dielectric non-elastomeric filaments are known. Platinum can be used for knitting when all three yarns are knit together. Here, conductive wires are used as electrical lines that connect the control elements connected to each other: sensors, converters, signal processing and transmission devices, etc. In these fabrics, conductive filaments are not used as sensitive elements of the control system.

Knitted fabric and sesnor knitwear are known [3]. The sensors are only knitted from electrically conductive filaments and are embroidered with a jacquard "intarsia" cloth. This cloth and articles are used as part of heart, muscle and human respiratory control systems. The disadvantage of this fabric, as can be seen from the studies [4], is the low sensitivity of the sensors to deformation and thus the low accuracy and protection of control interference.

Closest to the bidder is the invention described in [5]. A conversion device is provided which is knitted and comprises at least one electrically conductive zone knitted from electrically conductive elastomers and non-elastomeric filaments. The deformation of a given zone affects its electrical parameters. Different knitting variants of this area are available to obtain different sensors. For example, for motion sensors, the conductive zone is manifested in some rows of knitted fabric knitted from conductive and resistive yarns. The edges of the conductive zone are the sensor contacts. The electrically conductive zone thus fabricated may be integrated into the garment during its manufacture in the flat-fed equipment.

The disadvantage of this invention is the low sensitivity of the proposed sensors [4]. In addition, constant friction of the loop elements (from conductive filaments in the conductive zone) leads to the destruction of the conductive layer in the filament coating [6]. Therefore, such a conductive zone has low resistance.

The purpose of the present invention is to increase the sensitivity and durability of electrical parameters of a resistive knitted fabric, and to develop a method of using a resistive knitted fabric to control body deformities, joint movements, muscle tension, respiratory rhythm, ECG.

Fig. 1 - Knitted or crocheted fabrics: (a) Example of platinum weave; (b) loose-fitting knitted or crocheted fabric; (c) semi-stretch knitted fabric: (d) fully knitted fabric.

Fig. 2 - Elastic knitted or crocheted fabrics: (a) loose; (b) in an extended position.

Fig. 3 - Electrical models equivalent to a fragment of a resilient knitted fabric, when stretched parallel to the loop bars:

(a) in free position; (b) detachment of some loops made of resistive yarn in the partially stretched position; (c) in the fully extended position.

Fig. 4 - graph of the resistance dependence of the cross-linked knitted fabric on its relative deformation, stretched parallel to the loop bars.

Fig. 5 - Cross-linked, knitted, knitted or crocheted fabric with press loops formed from the resisting yarn in (a) free and (b) extended.

Figure 6 - Resistant knitted fabric in the form of a knitted tube: (a) The resistive and insulating yarn is cast in the form of a solenoid; (b) the resistive and insulating filament is knotted in the form of closed rings; (c) the resistive and insulating filaments shall be inserted in the form of open rings.

Fig. 7 - An example of a control system in which a resistive knitted fabric is used as a sensitive element.

Fig. 8 - examples of textile products made using only a knitted cloth of resistance.

Fig. 9 - Examples of textiles whose parts are made using a resistive knitted cloth.

The essence of this invention is as follows. The resistive knitted fabric is knitted using electrically conductive, dielectric insulating filaments and dielectric elastomeric filaments. The elastomeric filament is a warp filament and is knit along the entire length of the fabric, while the resistive and insulating filament is a functional filament, spun separately from each other, but together with an elastomeric filament, in a specific order.

An example of such a fabric would be a resistive knitted fabric knit in platinum (Fig. 1a), where A - basic yarn serves as a weft yarn, B - yarn - serves as a functional yarn.

In a cross-linked resistive knitted fabric, the functional yarns are interlaced so that at least one loop of loops formed between the loops is formed between loops of resistive yarn. The number of rows of loops formed by the insulating thread depends on the type of weave by which the resistive thread is inserted. Similarly, in a longitudinally knitted resistive knitted fabric, the number of loops that are inserted with the insulating thread between the loops formed by the resistive yarn depends on the type of weave used to knit the resistive yarn.

A variety of resistive filaments can be used: polymeric filament filaments, metallic filaments and other filaments with different electrical properties.

The insulation yarns used can be any natural, artificial or synthetic yarn.

The elastomeric backbone yarn can be any elastomeric yarn, such as elastane, dorlostane, and the like.

Different types of resistive and insulating yarns with different properties can be used in different parts of the knitted fabric. Resistant knitted fabrics can be used to highlight different parts of the fabric, where different types of resistive yarns with different properties are used, and different color insulating yarns can be used.

The cross-linked resistive knitted fabric can be knit with the following weaves: plain weave, ribbed weave and weave, jacquard and press weave.

The following is an example of the loop structure characterization of a proposed resistive knitted fabric with a knitted resistive knitted fabric.

Knitted fabrics with elastomeric yarn during knitting stretch this yarn but try to return to their original length after knitting. Thus, the use of elastomeric weft yarn in a knitted resistive knit fabric results in all loop structure compression and loops formed from functional yarns that fit closely together, FIG. an example is the structure of a resistive knitted fabric with an elastomeric weft yarn (not shown) and an insulating (1) and resistive (2) functional yarn, Fig. 1b. corresponds to a loose-fitting knitted fabric; Fig. 1c corresponds to a resistive knitted fabric in the partially extended position; Fig. l.d corresponds to a resistive knitted fabric in the fully extended position in the direction of the loop bars (y-axis). The insulating thread (1) is inserted between each row of loops formed by the resistive thread (2).

Fig. lb. it can be seen that regardless of whether the rows of loops formed by the resistive yarn (2) are inserted, the rows of loops formed by the resistive yarn (2) are tightly pressed against each other. In addition, in such a compression, the rows of loops formed by two adjacent rows of resistive filament (2) not only contact each other, but also form whole contact areas designated by the letters a-k. In the event that a uniform tensile load is applied to the resistive knitted fabric in the y-axis (ie in the direction of the loop bars designated AE, i.e. in a direction perpendicular to the knitting direction), this fabric begins to stretch in the direction of the loop bars. area oh square.

Further stretching of the fabric leads to the disconnection of the rows of loops formed by the resistive filament (2) and, consequently, of the contact areas between the rows of cell loops, as shown in Fig. 1d. In the case of an uneven tensile load across the width of the resistive knitted fabric and, consequently, of an unevenly stretched loop, the change in the area of the contact areas in the direction of the loops (x axis) and the contact between these loops also occurs unevenly. For example, when applying a stretching load to the B and C columns, the first contact disconnection will occur in the c, d, e, f (Fig. C) zones. The remaining columns of the loops Λ E, D may still remain in contact in zones a, b, g, h, j, k.

A similar pattern is observed when the elongated knitted resistive fabric is stretched in a direction perpendicular to the knitting direction (Figures 2a-2b).

Since stretching of the resistive knit fabric in a direction perpendicular to the direction of knitting results in disconnection or deterioration of the contacts, a change in the equivalent resistance of the resistive knitted fabric occurs between the rows of loops formed by the resistive yarn.

Fig. 3 shows the electrical patterns (Fig. 1b-1d) of the resistive knitted fabric equivalent to the contact area described above in the free position (Fig. 3a), in the partially extended position in the direction of the B and C posts with the contact loss in the c, d, e, f (Fig. 3b) and in the fully extended position in the y-axis (Fig. 3c). Notation in drawing: J? _e - equivalent resistance of the part of the fabric to be measured in the direction of the loops to be measured (Fig. 1b-1d); Rh - equivalent resistance of loop arc; Rf-platinum equivalent resistance; R _LL , R _L r - equivalent resistances of the right and left loop pins; Rku, Ra>, ..... Rsk equivalent resistance of contact areas α, b, k (b. 1).

Without the deformation of the resistive knitted fabric (Fig. 1b), the rows of loops made of the resistive yarn are completely joined. Accordingly, the ultimate values of resistances RKa, RKb, ..... Raj *.

These sizes are close to each other if the structure of the knitted fabric is uniform.

If a uniform tensile load is applied to the resistive knitted fabric in the y-axis (i.e., in the direction of the loop bars), the contact areas between adjacent rows of loops made of resistive yarn will decrease and therefore the values of resistance Rk _o , Rta>, Rxk will increase. Accordingly, the equivalent resistance R _e will also increase.

If an uneven tensile load is applied (Fig. Lc), the resistance of the knitted fabric over the contact areas will also increase unevenly. The loss of contact, for example, in zones c, d, e, f corresponds to the disconnection of the corresponding branches of the equivalent electrical model (Fig. 3b). This obviously leads to a significant increase in R _e .

Increasing the stretching load causes a gradual loss of contact between adjacent rows of loops made of resistive yarn over the entire width of the resistive knitted fabric (Fig. Ld). Accordingly, the equivalent electrical model will look as shown in Fig. 3c. It is evident from the drawing that in this case R _e = oo, ie the relevant part of the knitted fabric becomes a dielectric.

Under realistic conditions, knitted fabrics have a slight loop structure misalignment and load column distribution. Therefore, in practice, using the proposed resistive knitted fabric, stretching it can cause uneven resistance changes in the contact areas, or a temporary loss of contact between the loops in adjacent rows made of resistive yarn. Accordingly, the increase in equivalent resistance R _e will be monotonous but quite rapid. Consequently, the respective resistive knitted fabric has a high equivalent resistance to longitudinal deformation in its stretching direction perpendicular to the direction of knitting. Fig. 4 are graphs showing the equivalent electrical resistance versus the relative longitudinal extension of a resistive knitted fabric. The resistive knitted fabric is knit in a lacing with loops of loops made of insulating and resisting yarn. Elastane 22 Dtex, pneumatic with polyamide filament PA78 Dtex, is used as elastomeric backbone yarn. Insulating thread Cotton thread 25 Density, resistive thread Shieldex 110 * 2 Dtex, 34 f. The resistive knitted fabric is knit in the tube using a sock machine with a diameter of 3, 168 needles.

The sample length is 12 cm. Fig. 4a corresponds to a tubular pattern, Fig. 4b. - open knitted fabric with a resistance of -120 loops. Figures 4a-4b it can be seen that the relative elongation of the samples by only 10% causes a change in the equivalent electrical resistance of 30 and 4 times, respectively.

It follows from the foregoing that with the increase in the number of contact areas between the rows of loops made of resistive filament, the effect of one or more contact zones on the equivalent electrical resistance decreases, and conversely, as the number of contact zones decreases, their effect on the equivalent electrical resistance increases. This allows you to adjust the sensitivity of the knitted fabric by changing only the amount of loop bars (the width of the knitted fabric).

Similarly, the elasticity of elastic knitted fabric varies by changing the number of rows of loops (length of knitted fabric).

Using resistor knit fabric in control systems that are integrated into the garment (Fig. 9), it is not always possible to resize the resistor knit fabric. In addition, some textiles may be made entirely of resistive knitted fabric (Figure 8). The change in the number of contact zones and, consequently, the sensitivity of the knitted fabric to the deformation (hereafter the sensitivity change), without changing its size, is ensured by knitting rows of loops made of resistant yarn using jacquard and press weave. In this case, at least one loop of such a row must have the index Κ> 1. illustrates the braiding with press loops (index K = 2) in free position (Fig. 5a) and stretched in the direction of the loop bars. Between the rows knitted with resistive yarn 2, there are rows made of insulating yarn 1.

In the free state, under the influence of shrinkage forces (Fig. 5a), the structure of the elastomeric weft yarn (not shown) shrinks to form contact zones a, b, c, d. Stretching the resistive knitted fabric in the direction of the loops of the loops weakens the contacts in these areas, but disappears completely when it is stretched strongly (Fig. 5b). By changing the amount of press loops (index K> 1), the amount of contact areas and consequently the sensitivity to deformation can be adjusted without changing the width of the resistive knitted fabric. If there are few such zones, one or two press loops, the resistive knitted fabric becomes an electrical switch that responds to a certain amount of deformation in the direction of the loop rows. The size of this defonnation is determined by the yarn parameters used (elastic properties, density, etc.), the knitting process parameters (yarn tension, feed rate), the resistive knit fabric parameters (weave type, knitting density). The analogue situation is with a resistive knitted cloth using jacquard loops with index K> 1.

In the case of resisting yarns which are knitted with jacquard or press fabric with a loop index K> 1, the number of rows of loops N knitted with insulating yarn between rows of resistance yarns shall be:

N = K + 1

For a longitudinal knitted fabric, the number of bars formed by the insulating filament inserted between the bars of the resisting yarn is equal to the width of the braided report formed by the resisting yarn.

From the above it can be concluded that the proposed loop structure, unlike the prototype [5], has no intersection of the resistive yarn loop elements, but due to the high sensitivity of the resistive knitted fabric offered, the resistive yarn rows / columns are subject only to minor deformations. As a result, the conductive layer that covers the resistive filaments will wear out, subject to dangerous folding loads and significantly less friction. This obviously increases the durability of the knitted fabric compared to the prototype [5].

The resistive knitted fabric can be made in the expanded form and in the form of a tube. In the latter case, the resistive filaments may be in the form of a continuous solenoid (Fig. 6a), a closed ring (Fig. 6b) or an open ring (Fig. 6c).

The choice of type of webbing for the weaving of the resistive yarn and the type of knitted fabric (stretch or tubular) depends on the field of application (flat garment, sleeve, sock, etc.) and functions (local strain control, respiratory control, joint movement control, etc.).

Fig. 7 illustrates examples of the use of a resistive knitted fabric as a sensitive element in a control system. Control system for knee, ankle and tension muscles. The system consists of a resistive knitted fabric 1, made in the form of a socks, an energy source 2, a signal control device 3, a data processing and transmission device 4, electrically conductive lines 5-7. These lines connect the pairs of control points a'a ', b'b', c'c 'to power source 2 and electrical signal control device 3.

The foot movements are caused by resistive knitted fabrics 1 in the deformation zones a'a "and b'b" and the knee bending and bending in the zones c'c ". The deformation of a resistive knitted fabric causes a change in the resistance parameters of the respective zone controlled by the device 3. The signal received from the electrical signal control device 3 is transmitted to the device 4 for processing and further transmission, for example, to a computer or mobile phone 8.

The resilient knitted fabric offered can be used to make whole textiles (gloves, socks, etc.) (Fig. 8), as well as being part of garments (Fig. 9).

With the help of modern knitting machines, the knitted fabric can be made partially or completely simultaneously with the production of the textile product. For this purpose, the technology of making seamless products, which is realized by flat-forming machines, is used. If necessary, the resistive knitted fabric may also be sewn or bonded to the textile product by any other known means. Fig. 9 illustrates examples of textiles with integrated knitwear for controlling movement of knee and leg muscles -1; separately for knee joint control - 2; for respiratory control - 3.4; heart rate control - 5; hand control - 6; for controlling the function of the hand muscles - Fig. 7. Also illustrated are conductive lines 8 and an electronic unit 9 comprising a power source, a control device, data processing and transmission devices.

Based on the foregoing, the present invention also provides a method of using a resistive knitted fabric for controlling body part deformation, joint movement, muscle tension, respiratory rate, ECG. The method comprises the manufacture of a textile product consisting wholly or partly of knitted or crocheted resistive knitted fabric, using a dielectric elastomeric backbone, an electrically conductive resistive and a dielectric insulating functional filament. The loop bars / rows made of insulating and resisting yarns are injected in a specific order such that the deformation of the loop bars / rows in a direction perpendicular to the knitting direction causes the electrical parameters of the resistive knitted fabric to change. The resilient knitted cloth shall be placed on the textile product in such a way that, when the article is worn, the controlled parts of the body are covered with a resilient cloth. The electrical signal shall be applied to the relevant parts of the resistive knitted fabric, the changes in the electrical parameters of the resistive knitted fabric shall be monitored and analyzed. An example of this method is shown in Fig. 9.

Literature

1. Patent DE102004038636A1

2. Patent WO2003087451A2

3. Patent WO2005053532A1

4. R.Wijesiriwardana, T.Dias, S.Mukhopadhyay. Resistive Fiber-Meshed Transducers. Proceedings of the Seventh IEEE International Symposium on Wearable Computers (ISWC'O3), 2003.

5. WO 2004100784A2

6. O. Atalay, W. R. Kennon. Knitted Strain Sensors: Impact of Design Parameters on Sensing Properties. Sensors 2014,14,4712-4730.

Claims (11)

1. A resistive knitted fabric which is knitted from an electrically conductive, dielectric insulating and dielectric elastomeric filament, characterized in that the fabric consists of a braid of said filament, in which the elastomeric filament is a weft filament and the resistive and insulating filament is: functional filaments and are filed separately from each other but together with elastomeric filaments in a specific sequence. A resistive knitted fabric according to claim 1, which is cross-linked and has at least two rows of loops of resistive filament inserted and at least one row of insulating filaments inserted between them. The resistive knitted fabric of claim 2, which is knitted with plain weave, trimmings and the like derived therefrom, double fleece, semi-fleece and other webs with a loop index K <1, in which each row of loops made of an insulating thread is inserted. resistive thread loop rows. The resistive knitted fabric of claim 2, wherein the rows of resistive yarn are knitted with a press or jacquard of at least one loop index K > the number of rows of loops of insulating yarn inserted between the rows of resistive yarn, is determined by the formula: N = K + 1, where N - number of rows of loops made of insulating thread, inserted between rows of loops made of resistive yarn with jacquard or press loops; K is the maximum index of a row press or jacquard loop formed by a resistive thread. The resistive knitted fabric of claim 1, which is elongated and has at least two loops of resistive filament loops inserted but between them inserts of an insulating filament number equal to the width of the web of resistive filament. The resistive knitted fabric of any one of claims 1 to 5, wherein the resistive yarn and the insulating yarn are natural, artificial or synthetic yarns. The resistive knitted fabric of any one of claims 1 to 6, wherein different colored insulating threads are used on different parts of the fabric. A resistive knitted fabric according to any one of claims 1 to 7, knitted in an expanded or tubular form, in which the rows of loops formed by the resistive filament are inserted in the form of solenoids, closed rings or open rings. A control system comprising a resistive knitted fabric according to any one of claims 1 to 8, a power source for supplying an electrical signal to the resistive knitted fabric, a data processing and transmission device, electrical lines connecting at least two of the above control system elements. the ends of the conductive lines are connected to at least one controlled part of the knitted fabric. A textile article for controlling body and joint movements, muscle load, ECG, and respiration, made partly or wholly of a resistive knitted fabric according to any one of claims 1 to 8, comprising an integrated control system according to claim 9, wherein: parts made of knitted or crocheted fabrics comply with the controlled areas and are sewn, knitted or otherwise joined to textile parts. A method of using a resistive knitted fabric according to any one of claims 1 to 10 for controlling body deformation, joint movement, muscle tension, respiratory rhythm, ECG, comprising the manufacture of a textile product consisting wholly or partly of knitted or elastic knitted fabric. fabrics, woven with platinum, using a dielectric elastomeric backbone yarn, an electrically conductive resistive and dielectric insulating functional yarn, in which the columns / rows of insulating and resistive filaments are inserted in a specific order such that the strain of the columns / rows is perpendicular to the direction of knitting, causes the electrical parameters of the resistive knitted fabric to change in this direction, placing the resistive knitted fabric on the textile article in such a way that the controlled body parts draped with resistive cloth, supply of electrical signal to respective parts of resistive knitted fabric, control and analysis of changes in electrical parameters of resistive knitted fabric.