The original version of this article unfortunately contained a mistake. A small error in the energy-formula. The original correct formula should be (Formula presented.) 

Purpose: To compare fixed transverse textile electrodes (TTE) knitted into a sock versus motor point placed standard gel electrodes (MPE) on peak venous velocity (PVV) and discomfort, during calf neuromuscular electrical stimulation (calf-NMES). Methods: Ten healthy participants received calf-NMES with increasing intensity until plantar flexion (measurement level I = ML I), and an additional mean 4 mA intensity (ML II), utilizing TTE and MPE. PVV was measured with Doppler ultrasound in the popliteal and femoral veins at baseline, ML I and II. Discomfort was assessed with a numerical rating scale (NRS, 0–10). Significance was set to p < 0.05. Results: TTE and MPE both induced significant increases in PVV from baseline to ML I and significantly higher increases to ML II, in both the popliteal and femoral veins (all p < 0.001). The popliteal increases of PVV from baseline to both ML I and II were significantly higher with TTE versus MPE (p < 0.05). The femoral increases of PVV from baseline to both ML I and II were not significantly different between TTE and MPE. TTE versus MPE resulted at ML I in higher mA and NRS (p < 0.001), and at ML II in higher mA (p = 0.005) while NRS was not significantly different. Conclusion: TTE integrated in a sock produces intensity-dependent increases of popliteal and femoral hemodynamics comparable to MPE, but results in more discomfort at plantar flexion due to higher current required. TTE exhibits in the popliteal vein higher increases of PVV compared to MPE. Trial registration: Trial_ID: ISRCTN49260430. Date: 11/01/2022. Retrospectively registered.

Purpose

Physical inactivity is associated with muscle atrophy and venous thromboembolism, which may be prevented by neuromuscular electrical stimulation (NMES). This study aimed to investigate the effect on discomfort, current amplitude and energy consumption when varying the frequency and phase duration of low-intensity NMES (LI-NMES) via a sock with knitting-integrated transverse textile electrodes (TTE).

Methods

On eleven healthy participants (four females), calf-NMES via a TTE sock was applied with increasing intensity (mA) until ankle-plantar flexion at which point outcomes were compared when testing frequencies 1, 3, 10 and 36 Hz and phase durations 75, 150, 200, 300 and 400 µs. Discomfort was assessed with a numerical rating scale (NRS, 0–10) and energy consumption was calculated and expressed in milli-Joule (mJ). Significance set to p ≤ 0.05.

Results

1 Hz yielded a median (inter-quartile range) NRS of 2.4 (1.0–3.4), significantly lower than both 3 Hz with NRS 2.8 (1.8–4.2), and 10 Hz with NRS 3.4 (1.4–5.4) (both p ≤ .014). Each increase in tested frequency resulted in significantly higher energy consumption, e.g. 0.6 mJ (0.5–0.8) for 1 Hz vs 14.9 mJ (12.3–21.2) for 36 Hz (p = .003). Longer phase durations had no significant effect on discomfort despite generally requiring significantly lower current amplitudes. Phase durations 150, 200 and 400 µs required significantly lower energy consumption compared to 75 µs (all p ≤ .037).

Conclusion

LI-NMES applied via a TTE sock produces a relevant plantar flexion of the ankle with the best comfort and lowest energy consumption using 1 Hz and phase durations 150, 200 or 400 µs.

This case study reports the use of a new textile-electrode system for self-administered Phantom Motor Execution (PME) treatment at home in one patient with Phantom Limb Pain (PLP). In follow-up interviews, the patient reported reduced pain, increased mobility, and improved mental health, and aspects such as motivation, usability, support, and treatment outcome, could be recognized from an earlier study as crucial for successful implementation and adoption of the home-based long-term treatment. The findings are of interest to developers, providers, users, and researchers planning home-based clinical studies and/or scenarios based on technology-assisted treatment. 

Every year, approximately 3,000 people in Sweden undergo amputation of a body part. The use of a prosthesis can greatly improve the quality of life for these people. To improve the fi t and comfort of a prosthesis, a sock is used as an interface between the prosthesis socket and the stump. A three-dimensional (3D) body scanner can be used to take measurements that are used to produce individualized socks that improve fi t and comfort. The standardized method for taking measurements with a 3D body scanner often requires a standing position and hence a new scanning method is needed to improve the accessibility for 3D body scanning. This study aimed to create a scanning scenario and an algorithm for scanning amputation stumps for individualizing prosthesis socks for upper-body amputations. Vitronic VITUSSMART LC 3D Body Scanner was used in this study. The results show a seated position with arms slightly away from the body, scanned at 45° as the best. To measure the right upper arm and the left armpit, the best was to scan at a 315° angle. Paired t-tests showed no signifi cant differences compared with the 3D body scanner of traditional manual measurements. The proposed method exhibited good relative reliability and potential to facilitate the customization of prosthetic socks for amputees.

Electrical stimulation can be used for the treatment of various nerve and muscle injuries as well as acute and chronic pain conditions. An electrical pulse is applied to a muscle or nerve to activate excitable tissue using internal or external electrodes with the aim of building muscle strength, artificially creating or supporting limb movement or reducing pain. Textile electrodes offer several advantages over conventionally used disposable surface electrodes: they are flexible and re-usable and they do not require hydrogels, thereby avoiding skin irritation and allergic reactions and enhancing user comfort. This article presents a literature review that assesses the state of research on textile electrode constructions. Based on the review, production approaches and designs are compared, methods for evaluating stimulation discomfort and pain are proposed and issues related to user compliance are discussed. The article concludes with suggestions for future work focused on investigating the impacts of textile-based electrode parameters on comfort, convenience and ease of use.

Interaction and capturing information from the surrounding is dominated by vision and hearing. Haptics on the other side, widens the bandwidth and could also replace senses (sense switching) for impaired. Haptic technologies are often limited to point-wise actuation. Here, we show that actuation in two-dimensional matrices instead creates a richer input. We describe the construction of a full-body garment for haptic communication with a distributed actuating network. The garment is divided into attachable-detachable panels or add-ons that each can carry a two dimensional matrix of actuating haptic elements. Each panel adds to an enhanced sensoric capability of the human- garment system so that together a 720° system is formed. The spatial separation of the panels on different body locations supports semantic and theme-wise separation of conversations conveyed by haptics. It also achieves directional faithfulness, which is maintaining any directional information about a distal stimulus in the haptic input.

The major reason for preventable hospital death isvenous thromboembolism (VTE). Non-pharmacologicaltreatment options include electrical stimulation or compressiontherapy to improve blood flow in the extremities. Textileelectrodes offer potential to replace bulky devices commonlyused in this field, thereby improving the user compliance. In thiswork, the performance of dry and wet knitted electrodes incombination with pressure application to the electrode wasevaluated in neuromuscular electrical stimulation (NMES). Amotor point stimulation on the calf was performed on ninehealthy subjects to induce a plantarflexion and the requiredstimulation intensity as well as the perceived pain were assessed.The performance of the different electrode constructions wascompared and the influence of the pressure application wasanalysed. The results show that wet textile electrodes (0.9 %saline solution) perform significantly better than dry electrodes.However, opportunities were found for improving theperformance of dry textile electrodes by using an uneven surfacetopography in combination with an intermediate to highpressure application to the electrode (> 20 mmHg), e.g. by usinga compression stocking. Moreover, the smaller of the two testedelectrode areas (16 cm2; 32 cm2) appears to be favourable interms of stimulation comfort and efficiency.

Textile electrodes, also called textrodes, for biosignal monitoring as well as electrostimulation are central for the emerging research field of smart textiles. However, so far, only the general suitability of textrodes for those areas was investigated, while the influencing parameters on the contact impedance related to the electrode construction and external factors remain rather un-known. Therefore, in this work, six different knitted electrodes, applied both wet and dry, were compared regarding the influence of specific knitting construction parameters on the three-electrode contact impedance measured on a human forearm. Additionally, the influence of applying pressure was investigated in a two-electrode setup using a water-based agar dummy. Further, simulation of an equivalent circuit was used for quantitative evaluation. Indications were found that the preferred electrode construction to achieve the lowest contact impedance includes a square shaped electrode, knitted with a high yarn density and, in the case of dry electrodes, an uneven surface topography consisting of loops, while in wet condition a smooth surface is favorable. Wet electrodes are showing a greatly reduced contact impedance and are therefore to be preferred over dry ones; however, opportunities are seen for improving the electrode performance of dry electrodes by applying pressure to the system, thereby avoiding disadvantages of wet electrodes with fluid administration, drying-out of the electrolyte, and discomfort arising from a “wet feeling”. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

Interaction and capturing information from the surrounding isdominated by vision and hearing. Haptics on the other side, widens the bandwidthand could also replace senses (sense switching) for impaired. Haptictechnologies are often limited to point-wise actuation. Here, we show thatactuation in two-dimensional matrices instead creates a richer input. Wedescribe the construction of a full-body garment for haptic communication witha distributed actuating network. The garment is divided into attachabledetachablepanels or add-ons that each can carry a two dimensional matrix ofactuating haptic elements. Each panel adds to an enhanced sensoric capability ofthe human- garment system so that together a 720° system is formed. The spatialseparation of the panels on different body locations supports semantic andtheme-wise separation of conversations conveyed by haptics. It also achievesdirectional faithfulness, which is maintaining any directional information abouta distal stimulus in the haptic input.

This systematic review concerns the use of smart textiles enabled applications based on myoelectric activity. Electromyography (EMG) is the technique for recording and evaluating electric signals related to muscle activity (myoelectric). EMG is a well-established technique that provides a wealth of information for clinical diagnosis, monitoring, and treatment. Introducing sensor systems that allow for ubiquitous monitoring of health conditions using textile integrated solutions not only opens possibilities for ambulatory, long-term, and continuous health monitoring outside the hospital, but also for autonomous self-administration. Textile-based electrodes have demonstrated potential as a fully operational alternative to ‘standard’ Ag/AgCl electrodes for recording surface electromyography (sEMG) signals. As a substitute for Ag/AgCl electrodes fastened to the skin by taping or pre-gluing adhesive, textile-based electrodes have the advantages of being soft, flexible, and air permeable; thus, they have advantages in medicine and health monitoring, especially when selfadministration, real-time, and long-term monitoring is required. Such advances have been achieved through various smart textile techniques; for instance, adding functions in textiles, including fibers, yarns, and fabrics, and various methods for incorporating functionality into textiles, such as knitting, weaving, embroidery, and coating. In this work, we reviewed articles from a textile perspective to provide an overview of sEMG applications enabled by smart textile strategies. The overview is based on a literature evaluation of 41 articles published in both peer-reviewed journals and conference proceedings focusing on electrode materials, fabrication methods, construction, and sEMG applications. We introduce four textile integration levels to further describe the various textile electrode sEMG applications reported in the reviewed literature. We conclude with suggestions for future work along with recommendations for the reporting of essential benchmarking information in current and future textile electrode applications.

With few exceptions textiles have not been considered as means for obtaining actuation. This is surprising as textiles have many advantageous characteristics such as the D=M property, which stands for Doing Devices while Making the Material. This means that functions are introduced simultaneously as the material, such as in a weave, is built up tread by tread. Traditionally a thread could have a certain colour so in total an aesthetical pattern is formed. Now we take a step beyond this working with threadshaving more advanced functions. Included are fiber formed structures showing actuation behavior. 

This we employ here. We make fiber formed actuating structures (FAS) following the McKibben principle with braided mesh sleeves surrounding a prolonged inflatable tube. Here we worked with relatively large diameters in the relaxed state but show that there is prospect for obtaining relaxed diameters of less than 1 mm approaching the range of large scale weaving manufacturing.

We study the behavior of these fibre formed actuating structures individually. Length changes obtained are -20%.We then make textile constructions by integrating several of these FASes with textile processing. By this, we build simple models of fabrics showing actuating behavior.

This study shows how textile constructions can support or hinder overall movement. It is a first logical step in order to get an understanding of actuating fabrics based also on other actuating mechanisms.

The unification of textiles and electrics opens up many interesting possibilities for sensorics, actuation, energy transport, energy storage, and information transport. Electrics need conductive structures. Industrially knittable and weavable filaments and yarns are in this chapter overviewed in a typology of seven classes. These are the basics for the integration in approach that is put forward as a concept for successful production of smart textiles.Integration means that a "device" is (1) made by a textile production process and (2) made as a textile. We focus on smart textiles for mechanical sensoring that give an electrical output as these embrace such basic quantities as position, movement, speed, acceleration, elongation, forces, pressure, and vibration. Cases of mechanical sensors are demonstrated based on piezoelectricity and capacitive techniques. It is shown that these are promising technologies for smart textiles in general and the integration approach specifically.

INTRODUCTION

Effective ulcer management requires the wound to be in a moist but still breathable environment, to facilitate healing, absorb exudates and prevent maceration. One of the applicable methods to achieve this is the use of composite dressings. Most composite dressings are made of three layers to provide absorption and a bacterial barrier in a non- or semi-adherent cover. Various common textile materials such as cotton, polyester, polypropylene and cellulose can be used as different layers in those wound dressings. In addition to these established dressings, electrical stimulation therapy may be used in treating ulcers. It has been reported that electrical stimulation can reduce the area and depth of the wound in a shortened time compared to conventional treatment. In summary, encouraging wound healing results have been obtained both from using composite wound dressing and from applying of electrical stimulation. The aim of this study is to present a conceptual design based on a woven 3D structure that combines the composite wound dressing properties with electrical stimulation for pressure ulcers healing/management.

METHOD

In the suggested structure, different layers in X, Y and Z led were designed with different materials for different purposes.  The top layer consisting of a low-density web to provide a non-adherent layer combined with two textile electrodes made of conductive threads, the middle layer contributes pressure release and absorption of exudates, and the bottom layer next to the wound for moisture keeping while still allowing adequate ventilation.

Two key properties were addressed in the study: pressure release and the possibility to provide electrical stimulation of the wound. Simulation with COMSOL Multiphysics was used to study pressure distribution according to Hertz contact theory. The surface resistance of the electrodes were also studied using in-house designed four-point measurement probes.

RESULTS

The simulation results show the composite structure to exhibit good pressure release properties. Surface resistance testing proved that the textile electrodes have resistance in the magnitude of 10² indicating that textile electrodes can be used for electrical stimulation in ulcers healing.

The first results from this study demonstrate the feasibility to design a textile system combining established composite dressings solutions with means for electrical stimulation based on 3D weaving technique to be applied in pressure ulcer healing. 

Functionality, wearability, and user acceptance are critical issues for the development and eventual commercialization of the smart products. The use of smart clothing for medical reasons requires an understanding of the users’ perspective and the willingness to use the products. In this study, a smart clothing system has been developed for respiratory monitoring. Besides the functionality, the wearability from users' perspective has been considered though the design phases. Wearability and user acceptance have been examined by two questionnaires. Results shown the smart clothing system improves comfort and wearability compared with the ordinary respiratory monitoring device and most of the participants believe that using a smart clothing system will improve both health condition and quality of life.

Textile-based electrodes show great potential as substitution of conventional electrodes when long-time monitoring is required. The flexibility and high skin-electrode contacting area make it possible to avoid the use of contact gel, which may cause irritation to the patients' skin. In this study, textile-based electrodes were made by combining conductive materials with high absorption nature fibres with the intention to create and maintain a microenvironment that improve the contact between the skin and electrode by local sweating at the electrode site. Alternatively artificial sweat (i.e. saline) may be added for a similar effect. However, by adding nature fibres into the electrodes, the electrical properties of the electrodes are modified due to the ration of conductive yarns is decreased. In this paper, the surface resistivity in the warp and weft directions and its distribution were measured in a four-wire resistance mode. The resistivity of the conductive yarns, the type of nature fibres, the textile construction and the fabric pick density were selected as the independent variables and the surface resistivity in warp and weft measurement directions was the dependent variable to be analysed. Preliminary results show that the conductivity of the conductive yarns are more important than the fabric pick density; surface resistance were not measurable in warp direction of most plain weave fabrics since the conductive yarns were only involved in the weft direction, however, the resistance were measureable in the case of satin fabrics; and that the surface resistivity is more evenly distributed in weft direction than the warp direction

The long-term monitoring of biophysiological signals requires new types of sensor systems that are wearable and at the same time convenient for the users. This paper describes the design of a novel garment-based sensing system for the long-term monitoring of breathing rhythm. The system concept was realized in a prototype garment, integrated with coated piezoresistive sensors. The prototype garment was tested by five subjects, and compared with a standard piezoelectric respiratory belt. Each signal was quantitatively and qualitatively evaluated in the time and frequency domain to make sure that no medical and diagnostic information was lost. The results showed a good agreement between the garment-based sensors and the standard reference, where errors occurred only when the breathing rate was extremely high. The garment-based sensor system could also distinguish the predominance breathing compartment (chest versus abdominal breathing). The system could detect a 10 s pause in breathing, which could be of importance in studies of sleep apnea. A garment-based sensing system maintains the accuracy of the signal quality without reducing the comfort for the user. It makes possible long-term ambulatory monitoring and has home-based healthcare applications.

Fabric-based strain sensors have been developed using different technologies, among which flat knitting is one of the most effective and economical methods. However, knitted strain sensors are not often used in practical applications because the sensors usually exhibit large elastic hysteresis when they are deformed and subjected to stress during application. One possible approach to overcome these shortcomings is to introduce elastic properties at the yarn level by combining the conductive materials with elastic materials. In this paper, we demostrate a hybrid yarn made of a conductive yarn that winds around an elastic core yarn in a direct twisting device. The electro-mechanical properties of strain sensors knitted from the hybrid yarns were tested in order to characterize the sensors. This study consisted of two stages: the yarn preparation and the sensor characterization. In the first stage, two kinds of elastic core components (polyamide/Lycra and polyamide) and two kinds of conductive winding yarns (Bekinox BK50/1 and Bekinox BK50/2) were selected for twisting. The twisting was done with a constant twisting speed and four different numbers of twists. Mechanical properties, that is, the tenacity, force at break and elongation at break, were tested in order to determine the optimal parameters for producing the hybrid yarns. The results indicated that among the tested yarns those with a polyamide core and Bekinox BK50/1 winding yarns at 450 twist/meter and with a polyamide/Lycra core and Bekinox BK 50/2 winding yarns at 600 twist/meter had the best properties. These were thus selected as the materials for producing knitted strain sensors. In the second stage, electro-mechanical properties of the knitted strain sensors were determined under tensile stress and multi-cyclic tensile stress. The results show that the hybrid yarns can effectively enhance the

The monitoring and interpretation of respiration pattern plays an important role for the early detection and the prevention of serious illness, such as asthma, sleeping apnea, bronchitis, and lung cancer. In this interdisciplinary project a system based on a smart shirt with integrated textile sensor for personal respiratory monitoring was developed. Due to the fact that textile products are flexible, washable and bring no discomfort to wearers, the smart shirtis an excellent interface for performing long term respiratory monitoring in real life situations outside the clinic. Two stripe liked sensors located on the chest and abdomen position respectively were integrated in a smart shirt. The sensors were made by coating with conductive silicone on the fabric surface of the smart shirt. Conductive silicone reflects compression or extension by resistance change and in this application resistance change can be utilized to indicate the respiratory pattern of the wearer. A prototype system was made to record the resistance change in real time and transmission to a PC or PDA for further processing. Snap button and conductive threads were used as the interface and transmission wires between the smart shirt and the recording system. To verify the performance, test were made with 10 subjects, whose spontaneous respiratory patterns were recorded during sitting still, walking and jogging. In addition, a number of abnormal respiratory conditions, such as deep breathing, hyperventilation and sleeping apnea were simulated. The results show the smart shirt performed in a very good manner, the system can sense and record the person's breathing during normal daily activities. The sleeping apnea simulation indicates potential application in diagnosis and clinical treatment. The smart shirt is soft and comfortable to use and enables long-term monitoring to be performed outside the laboratory.

Textile based sensors were developed and used for remote monitoring of breathing. The breathing is simulated by using a new cyclic tester device. In the simulated a cyclic force is applied along the length of the textile sensor. However due to the morphology of human body, in real situation the sensor is not only under stretching but also under a certain degree of bending. A prototype garment with the sensor situated on the chest area was made. The prototype was worn by 10 persons, and breathing was recorded as the persons were sitting still, walking and jogging. Deep breathing in the supine position and breathing with a method called athletic breathing were used to evaluate the sensor. A testing circuit and a Labview program were made for preliminary test. The sensor is wearable, washable and comfortable. Sensor construction is totally ‘disappearing’ and visualize as printed pattern onto the surface of garment.

Abstract. The integration of performances in interactive textile fabric system has so far been rather complicated since they are based on multilayer or three-dimensional principles. These structures are today mainly put together by means of several processes, which is laborious and time consuming. In this interdisciplinary study we have combined the principle of a three-dimensional multilayer weaving process and interactive textiles structures in order to enable the manufacturing of interactive textile structure in one process. The process is investigated using a manual reconstructed loom and the approach has been to use the 3D structures in order to integrate and organize conductive and compressive spacer layers as a textile capacitive structure. Measurements on such a structure was done by construction a first order passive high pass filter and using the fabric sample as the capacitor and a 1MΩ resistor. The behavior of the measurement of the capacitive sensor is quite close to the theoretical calculation and already at this stage the structure might be used to indicate the presence of a pressure. In this project we have shown that a three-dimensional structure enables the development of interactive textiles in one process. Further the concept of using a rebuilt manual loom has shown great potential in early research stages. It is considerable saving time and resources since, in this case, it is easy to reconstruct the loom design compared to performing similar reconstruction on a machine. Future research will focus on developing other types of interactive structures. Another issue will be to scale down the size of the structures in order to get thinner and more flexible qualities.

Integreringen av interaktiva egenskaper i teknisk textil har rönt stort intresse inom textil-forskningen de senaste åren. Med interaktiva textila strukturer avses textila system som interagerar med sin omgivning i någon mening. Ett sätt att åtadkomma dessa interaktiva strukturer är att foga samman lager av olika struktur eller material där varje lager tillför textilen/det textila systemet olika egenskaper. Det typiska tillvägagångssättet för att sammanfoga olika lager av textila material är att använda någon form av lamineringsteknik. Föreliggande projekt rör en ny vävteknik som möjliggör att flera textila lager med olika egenskaper vävs samman i en och samma process utan de tillsatser eller extra hantering som krävs vid laminering. Utöver de uppenbara produktionstekniska fördelarna möjliggör kombinationen av olika egenskaper i en lagerstruktur också att speciella krav på slutprodukten lättare kan tillgodoses. Det medicintekniska området förväntas ha stor nytta av textila strukturer som kan utformas i tre dimensioner eller kombinera olika egenskaper i en och samma struktur. Syftet är att demonstrera hur en nyutvecklad vävteknik för tredimensionella strukturer kan tillämpas för att tillverka interaktiva textila strukturer i en och samma tillverkningsprocess. I detta delprojekt har den tredimensionella tekniken använts för att utveckla en kapacitiv struktur utformad helt i textil. Genom mindre modifieringar av och tillägg till en 16-skaftad datorstyrd manuell prototypvävstol har två ledande och ett isolerande skikt kombinerats för att realisera en textilbaserad kondensator. I ett första test realiserades ett enkelt högpassfilter med den kapacitiva textila strukturen som kondensator. Filtrets egenskaper visade sig väl följa den förväntade filterkarakteristiken. Den nyutvecklade tredimensionella vävtekniken förväntas ha stora tillämpningsmöjligheter inom det medicintekniska området.

In this paper 4 different textile based strain sensors for measuring different level of strains were presented. Sensor consist a conductive part formed by coating or weaving technique. Both elastic and inelastic textile substrates were selected to achieve the required stains in applications. Sensor configuration was characterized using a tensile tester and measuring the resistance parallel by microprocessor. A linear working range with transfer function of each sensor was found. Coated sensor gives a good stability, while woven sensor was relative less stable. Inelastic textile substrate reduces the hysteresis error caused by refraction and construction of materials. The sensitivities were between 2.5 to 9 vary with different sensors. This paper finished by a discussion of how to choose sensors with different applications, among which sensor function and processability are most important aspects to be considering.

This project has focused on test and evaluation of three different textile sensors. The project includes the development of sensors, the exploration of suitable measurement methods and devices and finally the evaluation of the sensors according to three different applications. Four results were given in order to characterize sensor performance and to verify the effective working ranges. Further the sensors were integrated in three applications such as force sensor, breath sensor and movement sensor in order to test the sensor functionality by application. Future research orientation has suggested by the end of the paper.