Functionalised fabrics and wearer interaction

This talk will present wearable sensor research carried within CLARITY - Centre for Sensor Web Technologies. The aim of CLARITY is to bridge the molecular and digital worlds. This interdisciplinary research encompasses all stages of development - from novel materials and sensor research right through to end user applications. The research theme is to “Bring information to life” - there is much information that can be harvested about our bodies and the environment we move through using sensor technology, the important question is what to do with all the information? It is vital to develop interactive systems that are accessible and straightforward to use. Two case studies will be presented of systems for use in hospital wards and home settings – a sensor glove for stroke rehabilitation and a breathing feedback system for respiratory rehabilitation and stress management. Another area of research involving smart fabrics for healthcare is on-body chemical analysis. This is a new and challenging concept in the field of smart fabrics and interactive textiles. This work commenced as part of the EU BIOTEX project, and in this paper we present lessons learnt and current developments and findings. Sensor glove Carbon-loaded elastomer(CE) sensors have piezo-resitive properties which can be used to detect hand movements. The CE sensors are integrated into an oedema glove which is often worn by stroke patients to reduce swelling in the hand. The glove is used to assess the patient’s performance by scoring the movements based on the Fugel-Meyer Assessment system which assesses various motor functions (0 = cannot perform; 1 = performs partially; 2 = performs fully). This method of garment-based sensed information/personalised user feedback would allow an individual to be assessed from home on a continual basis under remote supervision by a trained physical therapist. Breathing feedback A vest integrating CE stretch sensors has been developed to measure breathing patterns. Patients with respiratory illnesses often tend to take shallow short breaths which exacerbates chest muscle weakness, and associated reduced oxygen circulation, shortness of breath and fatigue. Proper breathing exercises can help to reduce these symptoms as well as strengthen muscles, improve posture and enhance mental attitude. This paper presents a wearable system which monitors breathing technique and provides straightforward feedback to the user through a graphical interface. An avatar displayed on the screen encourages diaphragmatic breathing while a real-time representation of the user’s breathing technique is also displayed. The user’s goal is to perform deep diaphragmatic breathing in synchronization with the avatar. Real-time sweat analysis Real-time analysis of sweat loss is an exciting prospect for the sports industry. Replacing the fluids and electrolytes lost during exercise is vital to ensure adequate hydration which affects health and performance. We have developed a wearable device to provide immediate feedback to the user regarding the pH level of their sweat. An array of pH indicators are used to create a coloured barcode onto thin layers of poly(methyl methacrylate) (PMMA). The barcode sensor is flexible and can adapt to the contours of the body easily. It is integrated into a sweat band to be placed on different body regions e.g. forearm, wrist or forehead. We have also developed a wearable microfluidic device to sample and analyse small quantities of sweat

Near-Infrared Spectroscopy for Brain Computer Interfacing

A brain-computer interface (BCI) gives those suffering from neuromuscular impairments a means to interact and communicate with their surrounding environment. A BCI translates physiological signals, typically electrical, detected from the brain to control an output device. A significant problem with current BCIs is the lengthy training periods involved for proficient usage, which can often lead to frustration and anxiety on the part of the user and may even lead to abandonment of the device. A more suitable and usable interface is needed to measure cognitive function more directly. In order to do this, new measurement modalities, signal acquisition and processing, and translation algorithms need to be addressed. This work implements a novel approach to BCI design, using noninvasive near-infrared spectroscopic (NIRS) techniques to develop a userfriendly optical BCI. NIRS is a practical non-invasive optical technique that can detect characteristic haemodynamic responses relating to neural activity. This thesis describes the use of NIRS to develop an accessible BCI system requiring very little user training. In harnessing the optical signal for BCI control an assessment of NIRS signal characteristics is carried out and detectable physiological effects are identified for BCI development. The investigations into various mental tasks for controlling the BCI show that motor imagery functions can be detected using NIRS. The optical BCI (OBCI) system operates in realtime characterising the occurrence of motor imagery functions, allowing users to control a switch - a “Mindswitch”. This work demonstrates the great potential of optical imaging methods for BCI development and brings to light an innovative approach to this field of research

Fibers and fabrics for chemical and biological sensing

Wearable sensors can be used to monitor many interesting parameters about the wearer’s physiology and environment, with important applications in personal health and well-being, sports performance and personal safety. Wearable chemical sensors can monitor the status of the wearer by accessing body fluids, such as sweat, in an unobtrusive manner. They can also be used to protect the wearer from hazards in the environment by sampling potentially harmful gas emissions such as carbon monoxide. Integrating chemical sensors into textile structures is a challenging and complex task. Issues which must be considered include sample collection, calibration, waste handling, fouling and reliability. Sensors must also be durable and comfortable to wear. Here we present examples of wearable chemical sensors that monitor the person and also their environment. We also discuss the issues involved in developing wearable chemical sensors and strategies for sensor design and textile integration

Textile-based wearable sensors for assisting sports performance

There is a need for wearable sensors to assess physiological signals and body kinematics during exercise. Such sensors need to be straightforward to use, and ideally the complete system integrated fully within a garment. This would allow wearers to monitor their progress as they undergo an exercise training programme without the need to attach external devices. This takes physiological monitoring into a more natural setting. By developing textile sensors the intelligence is integrated into a sports garment in an innocuous manner. A number of textile based sensors are presented here that have been integrated into garments for various sports applications

Breathing feedback system with wearable textile sensors

Breathing exercises form an essential part of the treatment for respiratory illnesses such as cystic fibrosis. Ideally these exercises should be performed on a daily basis. This paper presents an interactive system using a wearable textile sensor to monitor breathing patterns. A graphical user interface provides visual real-time feedback to patients. The aim of the system is to encourage the correct performance of prescribed breathing exercises by monitoring the rate and the depth of breathing. The system is straightforward to use, low-cost and can be installed easily within a clinical setting or in the home. Monitoring the user with a wearable sensor gives real-time feedback to the user as they perform the exercise, allowing them to perform the exercises independently. There is also potential for remote monitoring where the user’s overall performance over time can be assessed by a clinician

Hands on with electronic textiles (E-textiles) – promoting technology through craft and design

Novel wearable technologies are changing the way we live – not only supplying us with the desired information in an instant but also in monitoring health, fitness and lifestyle. While smartwatches and similar devices are dominating the “Wearables” trend, smart garments with textile based electronic systems have the capability to enhance the functionality of our clothing. This creates a new interface to interact with our own body and its surrounding environment

A textile-based platform for real-time sweat collection and analysis

The ability to perform real-time chemical measurements of body fluids is an exciting concept for the healthcare sector and the sports industry. This work is part of the BIOTEX project, an EU FP6 project which involved the development of textile-based sensors to measure the chemical composition of sweat. This is a challenging task involving the collection of sweat samples, delivery to an active surface and the removal of waste products. A textile based platform which would be in immediate contact with the skin was developed for this purpose. The system uses capillary action and exhibits a passive pumping mechanism. This is achieved by using a combination of moisture wicking fabric and a highly absorbent material. A fabric channel is created for the integration of sensors. The channel is produced using a mask and screen-printing hydrophobic material onto the fabric. Different channel lengths and widths affect the flow rate of the system. The channel dimensions were designed based on typical sweat rates and also to accommodate sensor placement. A textile patch was developed and integrated into a waistband for collection of sweat on the lower back. Real-time measurements of sweat pH, sodium concentration, conductivity and temperature were measured during exercise using the textile patch