Developing novel temperature sensing garments for health monitoring applications

Embedding temperature sensors within textiles provides an easy method for measuring skin temperature. Skin temperature measurements are an important parameter for a variety of health monitoring applications, where changes in temperature can indicate changes in health. This work uses a temperature sensing yarn, which was fully characterized in previous work, to create a series of temperature sensing garments: armbands, a glove, and a sock. The purpose of this work was to develop the design rules for creating temperature sensing garments and to understand the limitations of these devices. Detailed design considerations for all three devices are provided. Experiments were conducted to examine the effects of contact pressure on skin contact temperature measurements using textile-based temperature sensors. The temperature sensing sock was used for a short user trial where the foot skin temperature of five healthy volunteers was monitored under different conditions to identify the limitations of recording textile-based foot skin temperature measurements. The fit of the sock significantly affected the measurements. In some cases, wearing a shoe or walking also heavily influenced the temperature measurements. These variations show that textile-based foot skin temperature measurements may be problematic for applications where small temperature differences need to be measured

Electronically active textiles

Electronically Active Textiles (e-textiles) are a type of textile material that has some form of electronic functionality. This can be achieved by attaching electronics onto the surface of the textile, incorporating electronic components as part of the fabrication of the textile itself, or by integrating electronics into the yarns or fibers that comprises the textile. The addition of electronic components can give textiles a wide range of new functions from lighting or heating to advanced sensing capabilities. As such, e-textiles have provided a platform for developing a range of new novel products in fields, such as healthcare, sports, protection, transport, and communications. The purpose of this volume is to report on the advances in the integration of electronics into textiles, and presents original research in the field of e-textiles as well as a comprehensive review of the evolution of e-Textiles. Topics include the fabrication and illumination of e-textiles and the use of e-textiles for temperature sensing

Development of a yarn capable of measuring localised temperature

In this research an electronic temperature sensor (ETS) yarn has been developed by embedding a commercially available thermistor chip into the fibres of a yarn. A polymer resin is used to encapsulate the thermistor creating a micro-pod which protects the thermistor from mechanical and chemical stresses during use, and also allows the ETS yarn to be washed. The thermistor micropod and interconnects were then encased within a warp knitted braid to from the ETS yarn. Temperature is the most widely measured physiological bio-marker in medicine. Temperature changes can indicate underlying pathologies such as wound infections or the formation of ulcers in diabetic patients. A temperature sensor capable of providing remote, continuous and localised (temperature at a given point) temperature measurements could provide clinicians with a powerful tool when handling such complications. Even though there are many flexible temperature sensors they lack true textile characteristics making them unsuitable in many situations. The existing textile-based temperature sensors are incapable of providing localised measurements and can suffer from hysteresis. At the start of the project a geometrical model of the ETS yarn was developed in-order to understand its design parameters. Then the crafting of the ETS yarn was achieved in three key stages. Hardware and software necessary to obtain temperature from the ETS yarn have been developed. Thereafter work has been conducted to characterise the behaviour of the thermistor and understand the design rules for the micro-pod. Theoretical models were created in COMSOL in-order to study the heat flow through the micro-pod and warp knitted braid, and the effect they have on the response and recovery times of the thermistor. The model has been validated using experiments. Results have shown that encapsulating the thermistor in a micro-pod and making it into a yarn has a minimal effect on the thermal time constant and that the resin of the micro-pod and fibres of the warp knitted braid have no significant impact on the accuracy of the temperature readings. The research into calibrating the ETS yarn has shown that the resistance-temperature conversion equation provided by the thermistor manufacturer provided the most accurate temperature measurement with 63 % of the readings being within ± 0.5 °C accuracy. Cyclic tests have been carried out on the ETS yarn to ensure that its performance is not effected by mechanical strain. Thereafter an evaluation of the response of the ETS yarn to operational conditions (ambient temperature, moisture content, wind speed) was studied. Finally, prototype temperature sensing garments have been produced using a network of ETS yarns. The necessary hardware and software to capture the temperature data from these prototypes has been developed. Finally, two prototypes have been created, a temperature sensing sock with five ETS yarn for detecting non-freezing cold injuries and a dressing with 16 ETS yarns to provide a temperature map of a wound. The temperature sensing sock was tested on volunteers. Both the wound dressing and the sock can provide remote, continuous and localised temperature measurements without compromising the textile characteristics of the fabric

Smart Textile Sock System for Athletes’ Self-Correction during Functional Tasks: Formative Usability Evaluation

Funding Information: This publication has been developed with financing from the European Social Fund and Latvian state budget within the project no. 8.2.2.0/20/I/004, “Support for involving doctoral students in scientific research and studies”, at Rīga Stradin, š University. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.(1) Background: The development of a lightweight, easy-to-use system that measures the foot’s plantar pressure is becoming an increasingly important area of research in physiotherapy. For further development of the smart sock system, a formative usability study was conducted, where the smart textile sock sensor system was used for self-correction during functional tasks; (2) Methods: Five athletes from the football school participated in the formative usability study. Athletes performed pre-defined functional tasks for self-correction when interacting with the smart textile sock system. Formative usability evaluation methods: effectiveness (task success rate, error rate), efficiency (time-based), satisfaction evaluated by System Usability Scale (SUS); (3) Results: Formative usability indicators: task completeness effectiveness ranged from 40% to 100% in the first-and second-stage tasks. Completed task efficiency time: Stage 1, from 4.2 s (SD 1.3) to 88.8 s (SD 19.8); Stage 2, from 7.2 s (SD 1.9) to 9.6 s (SD 2.1). Satisfaction was assessed by the SUS system user group with 76 points (SD 7.42), which indicates “good” satisfaction; (4) Conclusions: formative usability indicators showed the need for technical improvements to the smart textile sock pressure sensor system. The SUS results indicate “good” satisfaction with the smart textile sock pressure sensor system and its application.publishersversionPeer reviewe

A study of thermistor performance within a textile structure

Textiles provide an ideal structure for embedding sensors for medical devices. Skin temperature measurement is one area in which a sensor textile could be particularly beneficial; pathological skin is normally very sensitive, making the comfort of anything placed on that skin paramount. Skin temperature is an important parameter to measure for a number of medical applications, including for the early detection of diabetic foot ulcer formation. To this end an electronic temperature-sensor yarn was developed by embedding a commercially available thermistor chip into the fibres of a yarn, which can be used to produce a textile or a garment. As part of this process a resin was used to encapsulate the thermistor. This protects the thermistor from mechanical and chemical stresses, and also allows the sensing yarn to be washed. Building off preliminary work, the behaviour and performance of an encapsulated thermistor has been characterised to determine the effect of encapsulation on the step response time and absolute temperature measurements. Over the temperature range of interest only a minimal effect was observed, with step response times varying between 0.01–0.35 s. A general solution is presented for the heat transfer coefficient compared to size of the micro-pod formed by the encapsulation of the thermistor. Finally, a prototype temperature-sensing sock was produced using a network of sensing yarns as a demonstrator of a system that could warn of impending ulcer formation in diabetic patients

Smart Fabric sensors for foot motion monitoring

Smart Fabrics or fabrics that have the characteristics of sensors are a wide and emerging field of study. This thesis summarizes an investigation into the development of fabric sensors for use in sensorized socks that can be used to gather real time information about the foot such as gait features. Conventional technologies usually provide 2D information about the foot. Sensorized socks are able to provide angular data in which foot angles are correlated to the output from the sensor enabling 3D monitoring of foot position. Current angle detection mechanisms are mainly heavy and cumbersome; the sensorized socks are not only portable but also non-invasive to the subject who wears them. The incorporation of wireless features into the sensorized socks enabled a remote monitoring of the foot

Smart Diabetic Socks: Embedded device for diabetic foot prevention

1) Objectives Most foot ulcers are the consequence of a trauma (repetitive high stress, ill-fitting footwear, or an object inside the shoe) associated to diabetes. They are often followed by amputation and shorten life expectancy. This paper describes the prototype of the Smart Diabetic Socks that has been developed in the context of the French ANR TecSan project. The objective is to prevent pressure foot ulcers for diabetic persons. 2) Material and methods A fully wireless, customizable and washable "smart sock" has been designed. It is made of a textile which fibers are knitted in a way they provide measurements of the pressure exerted under and all around the foot in real-life conditions. This device is coupled with a subject-specific Finite Element foot model that simulates the internal strains within the soft tissues of the foot. 3) Results A number of derived stress indicators can be computed based on that analysis, such as the accumulated stress dose, high internal strains or peak pressures near bony prominences during gait. In case of risks for pressure ulcer, an alert is sent to the person and/or to the clinician. A watch, a smart-phone or a distant laptop can be used for providing such alert

Textile-based pressure sensors for step detection: a preliminary assessment

This paper presents the development and performance assessment of textile-based sensor based on a three layer architecture for the step detection. Two different transducing elements (EeonTex™ LG-SLPA and velostat) and electrodes (Satatex Techniktex P-130 and Elitex yarns) were selected for the construction of the sensors. The performance of the resulting sensors was assessed based on a dynamometer cyclic compression/decompression test with different compressions loads and at different speeds. Additionally, a real-life experiment was conducted to evaluate the sensor response during walking. The results show that all sensors configurations have a non-linear resistance-force relation. The best sensor configuration for the step detection was the combination of EeonTex™ LG-SLPA as a transducing element and the Elitex yarns for the electrodes. In this configuration, the resistance magnitude varies in an order of hundreds of kohms between the stance and the swing phases.This work was partially financed by FEDER funds through the Competitively Factors Operational Programme—COMPETE and by national founds through FCT -Foundation for Science and Technology within the scope of Project POCI-01-0145-FEDER-007136 and Project PEstOE/EEI/UI0319/2014. Authors would like to thanks André Paiva and Sérgio Branco for their collaboration in sensors production and data acquisition, respectively.info:eu-repo/semantics/publishedVersio

SMART GLOVE USAGE POSSIBILITY FOR BASKETBALL TRAINING: PROOF OF CONCEPT

Nowadays, basketball is one of the most entertaining and popular sports. In the last years, the number of people that are dedicating themselves to basketball has grown rapidly. The increasing number of sportsmen defines the increasing demand to monitor and analyse their performance, hereby granting the possibility to review and evaluate mistakes made within different game phases, which, in turn, would be useful for future training. The present research is the first step to develop a wireless system (Smart Basketball Glove (SBG)) for basketball shot analysis and training. SBG system is based on knitted tension and pressure sensors that were already successfully used in Smart Socks and Smart Shirt applications. These sensors, while embedded into the proposed system’s textile part, showed high tactile sensitivity and speed of response and, therefore, demonstrates potential abilities to analyse the wrist and fingers movement and estimate the forces with which fingers interact with the ball during basketball shot. Necessary requirements for data acquisition and transition device of SBG are formulated for further system’s development as well.