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Cuff design is the most important aspect to work on for the accurate measurement of blood pressure. For the very first time, pressure distribution underneath different parts/components of the fabric cuffs was analysed in detail using an advanced interface pressure sensing system. The pressure distribution at the interface of the selected cuffs and an arm simulator were measured experimentally while simulating blood pressure measurement. Fabrics are the main cuff constructing material and a relationship was found between cuff fabric properties and pressure at the interface of the cuff and the arm simulator. It was also found that the pressure distribution under different parts of the same cuff varied due to the uneven contact of the cuff fabric with the arm simulator. Components attached to cuff fabric which facilitate blood pressure measurement either confine or drive fabric according to their size and placement; they may cause non-uniform interface pressure distribution on the human arm too. It was also examined whether the selected cuffs were applying higher or lower average pressure over the surface of the simulator and the range varied from 8 mmHg to 25 mmHg. This indicates that the subsequent pressure distribution inside the arm tissues and over an artery would also vary further due to the cuffs being of different designs. This study found that cuffs would be unable to transfer the required pressure over the artery to block blood flow as and when needed.

Over the past few years, alternative power supplies to either supplement or replace batteries for electronic textile and wearable applications have been sought, with the development of wearable solar energy harvesting systems gaining significant interest. In a previous publication the authors reported a novel concept to craft a yarn capable of harvesting solar energy by embedding miniature solar cells within the fibers of a yarn (solar electronic yarns). The aim of this publication is to report the development of a large-area textile solar panel. This study first characterized the solar electronic yarns, and then analyzed the solar electronic yarns once woven into double cloth woven textiles; as part of this study, the effect of different numbers of covering warp yarns on the performance of the embedded solar cells was explored. Finally, a larger woven textile solar panel (510 mm × 270 mm) was constructed and tested under different light intensities. It was observed that a PMAX = 335.3 ± 22.4 mW of energy could be harvested on a sunny day (under 99,000 lux lighting conditions).

Falls can be detrimental to the quality of life of older people, and therefore the ability to detect falls is beneficial, especially if the person is living alone and has injured themselves. In addition, detecting near falls (when a person is imbalanced or stumbles) has the potential to prevent a fall from occurring. This work focused on the design and engineering of a wearable electronic textile device to monitor falls and near-falls and used a machine learning algorithm to assist in the interpretation of the data. A key driver behind the study was to create a comfortable device that people would be willing to wear. A pair of over-socks incorporating a single motion sensing electronic yarn each were designed. The over-socks were used in a trial involving 13 participants. The participants performed three types of activities of daily living (ADLs), three types of falls onto a crash mat, and one type of near-fall. The trail data was visually analyzed for patterns, and a machine learning algorithm was used to classify the data. The developed over-socks combined with the use of a bidirectional long short-term memory (Bi-LSTM) network have been shown to be able to differentiate between three different ADLs and three different falls with an accuracy of 85.7%, ADLs and falls with an accuracy of 99.4%, and ADLs, falls, and stumbles (near-falls) with an accuracy of 94.2%. In addition, results showed that the motion sensing E-yarn only needs to be present in one over-sock.

Temperature-sensing textiles have been proposed for a variety of applications, including health monitoring and sports. Skin temperature ( Tsk) measurements are an important parameter in performance sports and can be used to better understand thermoregulation during exercise. Currently, most Tsk measurements are taken using skin-mounted thermistors, which can be uncomfortable to the wearer, or thermal imaging, which can be difficult to implement and analyze. This work investigates the feasibility of using textile temperature-sensing electronic yarns (E-yarns) to measure human skin temperature during sub-maximal cycling trials. E-yarns were attached to commercially available cycling suits and measurements were recorded using both the E-yarns and the skin-mounted thermistors at rest and during sub-maximal cycling. Temperature readings were compared between the two temperature-sensing methodologies to determine the viability of using the temperature-sensing E-yarns for this application. Differences in the Tsk measurements as high as 5.9℃ between the E-yarns and skin-mounted thermistors for participants at rest have been shown. This work has also identified that a build-up of sweat significantly altered the Tsk recorded by the E-yarns in some cases. Further experiments explored the effect of saline solutions (simulating sweat) on the response of the temperature-sensing E-yarns. This work has highlighted boundary conditions for taking point Tsk measurement using electronic textiles.

BACKGROUND: Electromyographic systems are widely used in scientific and clinical practice. The reproducibility and reliability of these measures are crucial when conducting scientific research and collecting experimental data. OBJECTIVE: To test the reliability of surface electromyography signals from both the Flexor Digitorum Superficialis (FDS) and Extensor Carpi Radialis Brevis (ECRB) muscles of both the left and right arms during an individual, static multi-planar maximum voluntary contraction handgrip task using the Myon 320 system (Myon AG, Switzerland). METHODS: Eight right-handed male participants performed two maximal handgrip tests in five separate wrist positions using both hands. Muscle activity was recorded from both forearms. Reliability was measured using the Standard Error of Measurement (SEM), Coefficient of Variation (CV) and Intra-class correlation coefficients. Wrist joint position correlations within and between the FDS and ECRB muscle activities were also analysed. RESULTS: Absolute reliability was shown across all positions for both hands with CV and SEM recorded at below 10%. The output measures indicate that the Myon 320 system (Myon AG, Switzerland) produces good to fair reliability when assessing forearm muscle activity. Correlations in the left FDS muscles were negative. Correlations between the left ECRB and left FDS muscles were variable but positive between the right ECRB and right FDS muscles. CONCLUSIONS: The data sets retrieved from all participants were reliably evaluated. Wrist position correlations within and between the FDS and ECRB muscles may have been influenced by hand dominance. The findings demonstrate that the methods and systems outlined in this study can be used reliably in future research.

International audience; Only a small number of muscle activation patterns from lower limbs have been reported and simultaneous muscle activation from several lower limb muscles have not yet been investigated. The purpose of this study was to examine any gender differences in surface electromyography (EMG) activity from six recorded lower limb muscles of the dominant limb at baseline (i.e., with the foot placed flat on the floor and in the neutral position), and during concentric and eccentric phases when performing a heel raise task. In total, 10 females and 10 males performed a standing heel raise task comprising of three continuous phases: baseline, unloading (concentric muscle action), and loading (eccentric muscle action) phases. Muscle activation from six muscles (gastrocnemius medialis, gastrocnemius lateralis, soleus, tibialis anterior, peroneus longus, and peroneus brevis) were measured using the Myon 320 EMG System. Root mean squared values of each muscle were calculated for each phase. Descriptive and inferential statistics were incorporated into the study. Statistically significant p values were set at 0.05. The results showed no significant differences between baseline, concentric, and eccentric phases with respect to each of the muscles investigated. Except for the gastrocnemius medialis at baseline and concentric phases, no significant differences were observed between genders or contractions. The data suggests that gender does not significantly influence the eccentric phase during the standing heel raise task.

Knitted electrodes are a key component to many electronic textiles including sensing devices, such as pressure sensors and heart rate monitors; therefore, it is essential to assess the electrical performance of these knitted electrodes under different mechanical loads to understand their performance during use. The electrical properties of the electrodes could change while deforming, due to an applied load, which could occur in the uniaxial direction (while stretched) or multiaxial direction (while compressed). The properties and performance of the electrodes could also change over time when rubbed against another surface due to the frictional force and generated heat. This work investigates the behavior of a knitted electrode under different loading conditions and after multiple abrasion cycles.

Pulse rate (PR) is an important physiological parameter and can offer an indication of physical exertion. As such, optical pulse rate monitors for fitness tracking have grown in popularity in recent years and have featured as a component of many activity trackers and smart watches. These devices typically measure pulse rate using photoplethysmography (PPG) which requires an arrangement of a light emitting diode (LED) and a photodiode. The LED will emit light onto the skin and a portion of the light spectrum will be absorbed depending on the blood volume, with the transmitted or reflected light being measured by the photodiode. By recording the changes in the blood volume PR can be determined. This work presents a PR monitoring glove where an IR LED and a photodiode necessary for PPG have been discretely integrated into the structure of a textile. This has been achieved by using electronic yarn (E-yarn) technology where small electronic chips are soldered onto fine wires, encapsulated within a resin cylinder, and covered in fibers to create a mechanically and chemically robust yarn that looks and feels like a normal textile. The yarn production process, and the integration of the yarns into a textile, will affect the light emitted/collected by the optical components and these affects need to be fully quantified and understood so that an optimal sensing device can be engineered. Building on earlier studies this work investigates important design consideration, such as the emission pattern of the LED embedded Eyarns, in order to create a PR monitoring glove.

Background and Objectives: Nonintrusive heart rate (HR) monitoring can be a useful tool for health monitoring. By creating capacitively coupled textile electrodes, a comfortable monitoring system can be integrated into seating or bedding that can monitor HR through clothing. This work empirically studied two factors for a system of this type: the electrode size and the material worn by the subject. \ud \ud Materials and Methods: HR measurements were taken using six different sizes of the rectangular textile electrode with four subjects and the signal-to-noise ratio (SNR) of the signals were analyzed. A further set of experiments were conducted with a single subject and a fixed electrode size where different materials were worn. Results: Electrode size was seen to have a statistically insignificant effect on the collected signal quality. The SNR was also largely unaffected by the worn material type. \ud \ud Conclusion: This study provided empirical data relating to two important factors for nonintrusive, textile, and HR monitoring systems. This data will be helpful for designing a seat-based HR monitoring system or to understand the operational limitations of a system of this type.

Electronically active yarn (E-yarn) pioneered by the Advanced Textiles Research Group of Nottingham Trent University contains a fine conductive copper wire soldered onto a package die, micro-electro-mechanical systems device or flexible circuit. The die or circuit is then held within a protective polymer packaging (micro-pod) and the ensemble is inserted into a textile sheath, forming a flexible yarn with electronic functionality such as sensing or illumination. It is vital to be able to wash E-yarns, so that the textiles into which they are incorporated can be treated as normal consumer products. The wash durability of E-yarns is summarized in this publication. Wash tests followed a modified version of BS EN ISO 6330:2012 procedure 4N. It was observed that E-yarns containing only a fine multi-strand copper wire survived 25 cycles of machine washing and line drying, and between 5 and 15 cycles of machine washing followed by tumble-drying. Four out of five temperature sensing E-yarns (crafted with thermistors) and single pairs of LEDs within E-yarns functioned correctly after 25 cycles of machine washing and line drying. E-yarns that required larger micro-pods (i.e., 4 mm diameter or 9 mm length) were less resilient to washing. Only one out of five acoustic sensing E-yarns (4 mm diameter micro-pod) operated correctly after 20 cycles of washing with either line drying or tumble-drying. Creating an E-yarn with an embedded flexible circuit populated with components also required a relatively large micro-pod (diameter 0.93 mm, length 9.23 mm). Only one embedded circuit functioned after 25 cycles of washing and line drying. The tests showed that E-yarns are suitable for inclusion in textiles that require washing, with some limitations when larger micro-pods were used. Reduction in the circuit&rsquo, s size and therefore the size of the micro-pod, may increase wash resilience.

This paper presents the fundamental research of design, development, and evaluation of an active compression system consisting of silicone based inflatable mini-bladders, which could be used in applying radial pressure for the treatment of venous disease. The use of mini-bladders will nullify the effect of radius of curvature and provide a higher resolution to the pressure distribution. They are designed with two elastomeric layers and inflation is limited only to one side. The mini-bladders apply a radial force onto the treated surface when inflated, and the pressure inside mini-bladders could be measured using the concept of back pressure, which provides the flexibility to inflate mini-bladders to a predefined pressure. The 3-D deformation profile of the mini-bladders was analysed using finite element method (FEM) and FEM simulations were validated with experimental data, which showed good agreement within pressure region required for the treatment of venous disease. Finally, the pressure transmission characteristics of mini-bladders were evaluated on a biofidellic lower leg surrogate and the results have shown that the mini-bladders could apply a uniform pressure irrespective of the location on the leg with a 60%&ndash, 70% of inlet pressure successfully transmitted onto the leg surface, while 40%&ndash, 50% was available after the fat layers.

Textiles enhanced with thin-film flexible sensors are well-suited for unobtrusive monitoring of skin parameters due to the sensors&rsquo, high conformability. These sensors can be damaged if they are attached to the surface of the textile, also affecting the textiles&rsquo, aesthetics and feel. We investigate the effect of embedding flexible temperature sensors within textile yarns, which adds a layer of protection to the sensor. Industrial yarn manufacturing techniques including knit braiding, braiding, and double covering were utilised to identify an appropriate incorporation technique. The thermal time constants recorded by all three sensing yarns was &lt, 10 s. Simultaneously, effective sensitivity only decreased by a maximum of 14% compared to the uncovered sensor. This is due to the sensor being positioned within the yarn instead of being in direct contact with the measured surface. These sensor yarns were not affected by bending and produced repeatable measurements. The double covering method was observed to have the least impact on the sensors&rsquo, performance due to the yarn&rsquo, s smaller dimensions. Finally, a sensing yarn was incorporated in an armband and used to measure changes in skin temperature. The demonstrated textile integration techniques for flexible sensors using industrial yarn manufacturing processes enable large-scale smart textile fabrication.

The aim of the article is to report the research of the Advanced Textiles Research Group on the application of heat to enhance the moisture transmission in knitted spacer structures. The current trend in the design and development of moisture management textiles is to use knitted spacer structures. Generally, in moisture management textiles, the moisture is transmitted through the fabric due to capillary forces, which are influenced by the hydrostatic pressure difference between the two fabric layers and the geometry and the dimensions of the capillaries of the sandwiched fibre layer of a knitted spacer structures. However, the hydrostatic pressure difference is also influenced by the outer environmental changes. The research has demonstrated that the moisture transfer rate of up to 30% per 100 cm2 of fabric area can be achieved by creating a temperature gradient between the two layers of a knitted spacer structures. This temperature gradient was achieved by application of heat at one layer of the knitted spacer structures, which influenced the hydrostatic pressure difference of the knitted spacer structures. Application of heat to the knitted spacer structures was achieved by knitting small heater elements on side of knitted spacer structures to create an active moisture management structure. Wash tests, temperature rise rates and moisture wettability experiments of the active moisture management structure were performed, and the results are discussed in the publication.

This work demonstrates a novel and sustainable energy solution in the form of a photovoltaic fabric that can deliver a reliable energy source for wearable and mobile devices. The solar fabric was woven using electronic yarns created by embedding miniature crystalline silicon solar cells connected with fine copper wires within the fibres of a textile yarn. This approach of integrating solar energy harvesting capability within the heart of the textile fabric allows it to retain the flexibility, three‐dimensional deformability, and moisture and heat transfer characteristics of the fabric. In this investigation, both the design and performance of the solar cell embedded yarns and solar energy harvesting fabrics were explored. These yarns and resultant fabrics were characterised under different light intensities and at different angles of incident light, a critical factor for a wearable device. The solar cell embedded yarns woven into fabrics can undergo domestic laundering and maintained ~90% of their original power output after 15 machine wash cycles. The solar fabric embedded with 200 solar cells demonstrated here (44.5 mm × 45.5 mm active area) was capable of continuously generating ~2.15 mW/cm2 under one sun illumination and was capable of powering a basic mobile phone. The power generation capability and durability of the solar energy harvesting fabric proved its viability to power wearable devices as an integral part of regular clothing.

Most E-textile research tends to fall within the arts or science disciplinary boundaries, despite E-textiles themselves being interdisciplinary in nature. This work explores how contemporary woven textile practice methodologies can play a role within interdisciplinary research, expanding the creative and technical applications of materials and technologies. A team of electronics, textiles, and fashion specialists was formed to design and make an illuminated jacket for use by cyclists. The jacket incorporated bespoke woven panels that integrated electronic yarns within the pattern. The development of this prototype raised questions about the use of craft practice methodologies in the development of new E-textiles.

Overexposure to hand-transmitted vibrations (HTVs) is a serious concern within industries that use vibrating power tools as HTVs can lead to severe and chronic injuries to the hand-arm system, which are preventable by limiting vibration exposure. This study presents a novel vibration-sensing electronic yarn (E-yarn) that can be used to monitor HTVs at the point-of-entry of the vibrations into the hand. The construction of the vibration-sensing E-yarn is described, with the vibration-sensing E-yarns being fully characterised at each stage of the manufacturing process to understand how the manufacturing stages affect the behaviour of the embedded sensor. The results show that there is no significant difference in the sensor response at each of the three stages in the E-yarn production over a range of frequencies and amplitudes relevant to HTVs.

The measurement of pressure at the skin is highly important for a number of human-based monitoring applications. This work presents a resistive knitted spacer pressure sensor for monitoring the pressure at the skin–clothing–seat interface for wheelchair users. The sensor has been characterized over a relevant range of pressures, and its hysteretic behavior has been analyzed. Preliminary work towards creating supporting hardware for recording pressure at multiple junctions across the sensor has been presented.

Silicone-based elastomers saturated with embedded, short-strand fibres are used for their ability to mimic the aesthetic qualities of skin in clinical and theatrical maxillofacial appliance design. Well-known to prostheses fabricators and technicians, the mechanical impact of fibre addition on elastomeric behaviour endures as tacit, embodied knowledge of the craft, almost unknown in the literature. To examine mechanical changes caused by fibre addition, 100 modified polydimethylsiloxane (PDMS) elastomeric compounds containing incremental amounts of loose polyester fibres were prepared and examined in a variety of mechanical tests. It was found that elasticity and strain percentage at breaking point was reduced by increasing fibre content, but Young&rsquo, s modulus and ultimate tensile strength (UTS) increased. As fibre content was increased, strain hardening was seen at low strain rates, but exaggerated plastic deformation at high strain rates. PDMS hardness increased by 5 degrees of hardness (Shore-00 scale) for every additional percentage of fibres added and a strong positive linear coefficient (0.993 and 0.995) was identified to reach the hardness values given in the literature for living human skin. The apparent reorienting of loose fibres in the PDMS interrupts and absorbs stress during the loading process similar to the organic response to soft tissue loading, except in extension.

Electronic yarns (E-yarns) contain electronics fully incorporated into the yarn&rsquo, s structure prior to textile or garment production. They consist of a conductive core made from a flexible, multi-strand copper wire onto which semiconductor dies or MEMS (microelectromechanical systems) are soldered. The device and solder joints are then encapsulated within a resin micro-pod, which is subsequently surrounded by a textile sheath, which also covers the copper wires. The encapsulation of semiconductor dies or MEMS devices within the resin polymer micro-pod is a critical component of the fabrication process, as the micro-pod protects the dies from mechanical and chemical stresses, and hermetically seals the device, which makes the E-yarn washable. The process of manufacturing E-yarns requires automation to increase production speeds and to ensure consistency of the micro-pod structure. The design and development of a semi-automated encapsulation unit used to fabricate the micro-pods is presented here. The micro-pods were made from a ultra-violet (UV) curable polymer resin. This work details the choice of machinery and methods to create a semi-automated encapsulation system in which incoming dies were detected then covered in resin micro-pods. The system detected incoming 0402 metric package dies with an accuracy of 87 to 98%.

Overexposure to hand transmitted vibrations (HTVs) from prolonged use of vibrating power tools can result in severe injuries. By monitoring the exposure of a worker to HTVs, overexposure, and injury, can be mitigated. An ideal HTV-monitoring system would measure vibration were it enters the body, which for many power tools will be the palm and fingers, however this is difficult to achieve using conventional transducers as they will affect the comfort of the user and subsequently alter the way that the tool is held. By embedding a transducer within the core of a textile yarn, that can be used to produce a glove, vibration can be monitored close to where it enters the body without compromising the comfort of the user. This work presents a vibration-sensing electronic yarn that was created by embedding a commercially available accelerometer within the structure of a yarn. These yarns were subsequently used to produce a vibration-sensing glove. The purpose of this study is to characterize the response of the embedded accelerometer over a range of relevant frequencies and vibration amplitudes at each stage of the electronic yarn’s manufacture to understand how the yarn structure influences the sensors response. The vibration-sensing electronic yarn was subsequently incorporated into a fabric sample and characterized. Finally, four vibration-sensing electronic yarns were used to produce a vibration-sensing glove that is capable of monitoring vibration at the palm and index finger.

The main content dealt with in the paper is to present a kind of weft-knitted spacer fabric with high porosity. It is a kind of three-dimensional textile fabric with a sandwich structure that consists of a middle layer of multifilament and two outer layers of plain-knitted fabric. Compared with traditional warp-knitted spacer fabric as cushion mats, weft-knitted spacer fabric is well used as apparel for good softness, thermal/moisture comfort, and air permeability. Therefore, three structures were designed and nine samples were prepared by choosing plain-knitted fabric as the outer layers and selecting soft and thin multifilament as a middle layer. Experimental results show that this kind of weft-knitted spacer fabrics has high porosity, greater than 86%, and also demonstrate that the weft-knitted spacer fabric is suitable for comfortable apparel based on experimental results of air permeability, compression properties, stiffness, and thermal insulation properties.

Moisture management textiles have proved to be one of the fastest growing sector in textiles. New research and development of these textiles have pushed the boundaries of textile testing equipment as new test methods are required.\ud \ud This paper will focus on the development of test method with potential application in testing and analyzing of textile fabrics which can be used in moisture management industry. A new system has been developed which allows fabrics moisture transmission to be tested whilst situated between two variable conditions mini chambers. The system allows moisture level to be monitored by precision weight scale and all the real-time data can be controlled and analyzed by computer.\ud \ud The system was tested by using a knitted spacer fabric and proved to be useful and reliable kit for analysis of moisture transmission at various testing conditions.

The integration of small electronic components into textile fabrics, without compromising the textile qualities such as flexibility and conformability, is necessary in ensuring wider adoption of electronic textiles. A solution is to use flexible, electronic yarns that incorporate electronic components within the fibers of the yarn. The production of these novel yarns was initially a craft skill, with inclusion of electronics within each section of yarn taking 60 - 90 minutes. A prototype, automated production process was developed to speed up the manufacturing process to 6 minutes. This paper describes the process, using machinery and methods from both electronics and textiles applications.

The combination of electrical functionality and textiles has a long history. An electric corset from the 19th century promised rather dubious health benefits for ladies. A patent from 1911 describes some electrically heated gloves for “drivers of aeroplanes, automobiles, motor boats, and other conveyances which are guided by manually operated steering wheels.” Electric blankets began to have commercial success starting from the late 1930s. During the last three decades, there has been considerable interest in more sophisticated technologies and new generations of modern electronic textiles can be identified. The history of electric and electronic textiles will be briefly reviewed and the latest developments in the creation of a new generation of yarns integrated with semiconductor microchips within the fibers of yarns will be described.

Demos at UBICOMP 2015 provided researchers with an opportunity to present their latest cutting-edge research, but also early implementations, prototypes, work-in-progress systems, and commercial products. At UBICOMP, demos offer a chance for authors to engage the attendees and media representatives at a personal level and let them see, touch, and experience the future of ubicomp. Itiro Siio and Sidhant Gupta, UBICOMP 2015 Demo Chairs

In this article, the electromechanical properties of laser-engraved carbon-loaded fiber integrated with knitted fabric are investigated theoretically and experimentally. The fabric can be used as flexible strain sensor due to the change of resistance caused by change of the fabric configuration. In order to improve the sensitivity, linearity, repeatability of the knitted fabric strain sensor, laser treatment and integration with knitted structure are proposed. It can be seen from the results that the sensitivity of the fiber can be improved by laser engraving due to the change of the rigidity of fiber and conductive contacts created by laser corrosion on the surface of fiber. The repeatability of the integrated fabrics is improved due to the “push” effect created by fabric structures. Meanwhile, the linearity of fabric sensor with laser-treated fiber is higher than that without laser treatment due to the fiber pretension applied by fabric structure and the decrease of rigidity of fiber.