King Tong Lau

BIOTEX—Biosensing Textiles for Personalised Healthcare Management

Textile-based sensors offer an unobtrusive method of continually monitoring physiological parameters during daily activities. Chemical analysis of body fluids, noninvasively, is a novel and exciting area of personalized wearable healthcare systems. BIOTEX was an EU-funded project that aimed to develop textile sensors to measure physiological parameters and the chemical composition of body fluids, with a particular interest in sweat. A wearable sensing system has been developed that integrates a textile-based fluid handling system for sample collection and transport with a number of sensors including sodium, conductivity, and pH sensors. Sensors for sweat rate, ECG, respiration, and blood oxygenation were also developed. For the first time, it has been possible to monitor a number of physiological parameters together with sweat composition in real time. This has been carried out via a network of wearable sensors distributed around the body of a subject user. This has huge implications for the field of sports and human performance and opens a whole new field of research in the clinical setting.

Novel fused-LEDs devices as optical sensors for colorimetric analysis

The development of a novel, low power optical sensing platform based on light emitting diodes (LEDs) is described. The sensor is constructed from a pair of LEDs fused together at an angle where one LED functions as the light source and the other LED is reverse biased to function as a light detector. Sensor function is based on the level of light received by the detector diode, which varies with the reflectance of the interface between the device and its environment, or the chemochromic membrane that covers the device. A simple microprocessor circuit is used to measure the time taken for the photon-induced current to discharge the detector LED from an initial 5V (logic 1) to 1.7V (logic zero). This sensing device has been successfully used for colour and colour-based pH measurements and offers extremely high sensitivity, enabling detection down to the sub micro molar level of dyes.

Integration of analytical measurements and wireless communications—Current issues and future strategies

Rapid developments in wireless communications are opening up opportunities for new ways to perform many types of analytical measurements that up to now have been restricted in scope due to the need to have access to centralised facilities. This paper will address both the potential for new applications and the challenges that currently inhibit more widespread integration of wireless communications with autonomous sensors and analytical devices. Key issues are identified and strategies for closer integration of analytical information and wireless communications systems discussed.

Evaluation of a low cost wireless chemical sensor network for environmental monitoring

We present work on the development and testing of a low-cost wireless chemical sensor network (WCSN) for monitoring irritant/toxic gases in the environment. The WCSN used in this work takes advantage of recent advances in low power wireless communication platforms and uses colorimetric sensors to detect the presence of certain target gases. This sensor network adopts a star configuration and performs one way RF communications from individual sensor nodes to the base-station. Each node in the network is composed of a multiple sensor platform that measures light intensity, temperature and motion. The light sensor was used as the chemical sensing platform in such a way that the node is housed in a specially constructed sealed container that has a colorimetric chemical sensing film coated PMMA window aperture directly above the light sensor. The light intensity reaching the light sensor is modulated by changes in the colour of the sensing film and such changes indicate the presence of chemical plumes.

Photometric detection in flow analysis systems using integrated PEDDs

A novel inexpensive optical-sensing technique has been developed for colorimetric flow analysis. This sensing system employs two LEDs whereby one is used as the light source and the other as a light detector. The LED used as light detector is reverse biased with a 5-V supply so that the photocurrent generated by the incident light discharges the capacitance. Direct digital output is provided by a simple timer circuit that measures the time taken for this discharge process from 5V (logic 1) to 1.7V (logic 0). This sensing concept has been applied in flow analysis by constructing an optical flow cell with a pair of LEDs. Calibration of the integrated optical flow cell using a dye resulted in a linear response that obeys the Beer-Lambert law. The flow rate, dynamic range, sensitivity and limits of detection were investigated. The system was also used for pH determination in the range of pH 2.5-6.8 using bromocresol green (BCG). The pK(a) of BCG was successfully determined by this technique.

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.

Monitoring of headspace total volatile basic nitrogen from selected fish species using reflectance spectroscopic measurements of pH sensitive films

The release of amines from decomposing fish such as trimethylamine (TMA), dimethylamine (DMA) and ammonia, collectively known as total volatile basic nitrogen (TVB-N), are in high enough concentrations in headspace to be monitored by a colour change in a pH-sensitive sensor. A method developed here uses a pH indicator dye physically trapped in a cellulose polymer film to respond to the headspace TVB-N released from selected fish species during spoilage. Two species were selected for analysis on the basis of economic importance and the levels of volatile amines released were followed with time using uv/vis reflectance spectroscopic measurements. The results show that there is a significant increase in the TVB-N content in the headspace of fish samples after an incubation period of 8-12 h for cod and 12-15 h for orange roughy.

PSYCHE: Personalised monitoring systems for care in mental health

One of the areas of great demand for the need of continuous monitoring, patient participation and medical prediction is that of mood disorders, more specifically bipolar disorders. Due to the unpredictable and episodic nature of bipolar disorder, it is necessary to take the traditional standard procedures of mood assessment through the administration of rating scales and questionnaires and integrate this with tangible data found in emerging research on central and peripheral changes in brain function that may be associated to the clinical status and response to treatment throughout the course of bipolar disorder. This paper presents PSYCHE system, a personal, cost-effective, multi-parametric monitoring system based on textile platforms and portable sensing devices for the long term and short term acquisition of data from selected class of patients affected by mood disorders. The acquired data will be processed and analyzed in the established platform that takes into account the Electronic Health Records (EHR) of the patient, a personalized data referee system, as well as medical analysis in order to verify the diagnosis and help in prognosis of the illness. Constant feedback and monitoring will be used to manage the illness, to give patients support, to facilitate interaction between patient and physician as well as to alert professionals in case of patients relapse and depressive or manic episodes income, as the ultimate goal is to identify signal trends indicating detection and prediction of critical events.

In Situ One‐Step Electrochemical Preparation of Graphene Oxide Nanosheet‐Modified Electrodes for Biosensors

[zeng, fanwu; sun, zhenhua; su, dang sheng] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [zeng, fanwu; sang, xiaoguang; liu, xiaoxia] northeastern univ, dept chem, shenyang 110016, peoples r china. [diamond, dermot; lau, king tong] dublin city univ, sch chem sci, natl ctr sensor res, dublin d9, ireland.;zeng, fw (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china;xxliu@mail.neu.edu.cn dssu@imr.ac.cn

Validation of a fully autonomous phosphate analyser based on a microfluidic lab-on-a-chip

This work describes the design of a phosphate analyser that utilises a microfluidic lab-on-a-chip. The analyser contains all the required chemical storage, pumping and electronic components to carry out a complete phosphate assay. The system is self-calibrating and self-cleaning, thus capable of long-term operation. This was proven by a bench top calibration of the analyser using standard solutions and also by comparing the analysers performance to a commercially available phosphate monitor installed at a waste water treatment plant. The output of the microfluidic lab-on-a-chip analyser was shown to have sensitivity and linear range equivalent to the commercially available monitor and also the ability to operate over an extended period of time.