General-purpose passive wireless point–of–care platform based on smartphone

A versatile, compact and low-cost analytical platform has been designed, tested and validated to be used in the point-of-care settings. This passive measurement system is powered and complemented by a standard smartphone including a programmed application for measurement configuration and data processing as well as wireless results sharing. Electrochemical and electrochemiluminescence analytical techniques can be configured and realized by this platform that employs standard screen-printed electrodes for the sample managing and off-the-shelf electronic components. The power, electrical and optical signal processing have been studied in depth. The system can harvest energy up to 22.5 mW, set up a voltage in the range of ±1.15 V, and measure potentials in a range of 600 mV with an uncertainty of 1 mV, and current from 2 μA to 0.75 mA with a resolution of 1.1 μA. Moreover, standard tests have been performed to the platform consisting of amperometric, potentiometric, cyclic voltammetry and electrochemiluminescent analytical techniques, showing excellent agreement with a reference instrument. Finally, our design has also been applied to glucose, pH and H2O2 determinations, providing the full analytical parameters which are in very good agreement with the reference instrument results. Ranges (0.065–0.75 M, 0.62–100 mM and 3–9 pH units for glucose, H2O2 and pH, respectively) and limits of detection (0.024 M and 0.03 mM for glucose and H2O2, respectively) make this low-cost platform (<US$8) suitable for analytical applications.This study was supported by projects from the Spanish MINECO (CTQ2016-78754-C2-1- R), European Regional Development Funds (ERDF). and Spanish Ministry of Education, Culture and Sport for a R&D predoctoral grant (FPU13/05032

Passive Wireless Sensor Technology (PWST) 2012 Workshop Plan

No abstract availabl

Developing Biosensor Technology to Monitor Biofilm Formation on Voice Prosthesis in Throat Cancer Patients Following Total Laryngectomy

Voice prostheses (used to replace an excised larynx in laryngectomy patients) are often colonised by the yeast Candida albicans, yet no monitoring technology for C. albicans biofilm growth until these devices fail. With the current interest in smart technology, understanding the electrical properties of C. albicans biofilm formation is necessary. There has been great interest in Passive Radio Frequency Identification (RFID) for use with implantable devices as they provide a cost-effective approach for sensing. The main drawback of RFID sensors is the need to overcome capacitive loading of human tissue and, thus, low efficiency to produce a high read range sensor design. This is further complicated by the size restriction on any RFID design to be implemented within a voice prosthesis as this medical device is limited to less than 3 cm in overall size. In order to develop such a voice prosthesis sensor, we looked at three separate aspects of C. albicans colonisation on medical devices within human tissue. To understand if it is possible to detect changes within a moist environment (such as the mouth), we developed a sensor capable of detecting minute dielectric changes (accuracy of ± 0.83 relative permittivity and ± 0.05 S·m-1 conductivity) within a closed system. Once we understood that detection of dielectric changes within a liquid solution were possible, to overcome human tissue capacitive loading of RFID sensors. Adjusting backing thickness or adding a capacitive shunt into the design could limit this tissue effect and even negate the variability seen between human tissues. Without developing these methods, implementation of any RFID device would be difficult as human tissue variability would not be compensated for properly. Finally, biofilm growth in terms electrical properties. As C. albicans biofilm matures, there is a loss in capacitance (the biofilm becomes increasingly hydrophobic) prior to 24 hours after which the biofilm thickness shifts the resonance leading to a slow gain in capacitance. Understanding all of these aspects allowed us to develop two final voice prosthesis sensors producing read ranges above 60 cm and 10 cm within a tissue phantom. Ultimately, this showed the possibility of developing cost-effective passive RFID sensor technology for monitoring microbial biofilm formation within human tissue, leading to more effective real-time clinical care

Towards Wireless Characterization of Solvated Ions with Uncoated Resonant Sensors

Uncoated resonant sensors are presented here for wireless monitoring of solvated ions, with progress made toward monitoring nitrates in agricultural runoff. The sensor, an open-circuit Archimedean coil, is wirelessly interrogated by a portable vector network analyzer (VNA) that monitors the scattering parameter response to varying ionic concentrations. The sensor response is defined in terms of the resonant frequency and the peak-to-peak amplitude of the transmission scattering parameter profile (|S21|). Potassium chloride (KCl) solutions with concentrations in the range of 100 nM – 4.58 M were tested on nine resonators having different length and pitch sizes to study the effect of sensor geometry on its response to ion concentration. The resonant sensors demonstrated an ion-specific response, caused by the variations in the relative permittivity of the solution, which was also a function of the resonator geometry. A lumped circuit model, which fit the experimental data well, confirms signal transduction via change in solution permittivity. Also, a ternary ionic mixture (composed of potassium nitrate (KNO3), ammonium nitrate (NH4NO3), and ammonium phosphate (NH4H2PO4)) response surface was constructed by testing 21 mixture variations on three different sensor geometries and the phase and magnitude of scattering parameters were monitored. It was determined that the orthogonal responses presented by resonant sensor arrays can be used for quantifying levels of target ions in ternary mixtures. Applications of these arrays include measuring the concentration of key ions in bioreactors, human sweat, and agricultural waters. Preliminary results are shown for calibration standards and real waterway samples in Iowa, USA

Novel probes for pH and dissolved oxygen measurements in cultivations from millilitre to benchtop scale

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)pH value and the concentration of dissolved oxygen (DO) are key parameters to monitor and control cell growth in cultivation studies. Reliable, robust and accurate methods to measure these parameters in cultivation systems in real time guarantee high product yield and quality. This mini-review summarises the current state of the art of pH and DO sensors that are applied to bioprocesses from millilitre to benchtop scale by means of a short introduction on measuring principles and selected applications. Special emphasis is placed on single-use bioreactors, which have been increasingly employed in bioprocess development and production in recent years. Working principles, applications and the particular requirements of sensors in these cultivation systems are given. In such processes, optical sensors for pH and DO are often preferred to electrochemical probes, as they allow semi-invasive measurements and can be miniaturised to micrometre scale or lower. In addition, selected measuring principles of novel sensing technologies for pH and DO are discussed. These include solid-state sensors and miniaturised devices that are not yet commercially available, but show promising characteristics for possible use in bioprocesses in the near future

Real-time monitoring system for shelf life estimation of fruit and vegetables

The control of the main environmental factors that influence the quality of perishable products is one of the main challenges of the food industry. Temperature is the main factor affecting quality, but other factors like relative humidity and gas concentrations (mainly C2H4, O2 and CO2) also play an important role in maintaining the postharvest quality of horticultural products. For this reason, monitoring such environmental factors is a key procedure to assure quality throughout shelf life and evaluate losses. Therefore, in order to estimate the quality losses that a perishable product can suffer during storage and transportation, a real-time monitoring system has been developed. This system can be used in all post-harvest steps thanks to its Wi-Fi wireless communication architecture. Several laboratory trials were conducted, using lettuce as a model, to determine quality-rating scales during shelf life under different storage temperature conditions. As a result, a multiple non-linear regression (MNLR) model is proposed relating the temperature and the maximum shelf life. This proposed model would allow to predict the days the commodities will reduce their theoretical shelf-life when an improper temperature during storage or in-transit occurs. The system, developed as a sensor-based tool, has been tested during several land transportation trips around Europe.The authors are grateful to Fruca Marketing S.L. for providing the lettuce used in this research, and to Transportes Directos del Segura SL and Transportes Mesa SL for the logistic support. We also are grateful to Miriam Montoya Gómez for the translation services

The doctoral research abstracts. Vol:8 2015 / Institute of Graduate Studies, UiTM

Foreword: THIRTY FIRST October 2015 marks the celebration of 47 PhD doctorates receiving their scroll during UiTM 83rd Convocation Ceremony. This date is significant to UiTM since it is an official indication of 47 more scholarly contributions to the world of knowledge and innovation through the novelty of their research. To date UiTM has contributed 471 producers of knowledge through their doctoral research ranging from the field of Science and Technology, Business and Administration, and Social Science and Humanities. This Doctoral Abstracts epitomizes knowledge par excellence and a form of tribute to the 47 doctorates whose achievement we proudly celebrate. To the graduands, your success in achieving the highest academic qualification has demonstrated that you have indeed engineered your destiny well. The action of registering for a PhD program was not by chance but by choice. It was a choice made to realise your self-actualization level that is the highest level in Maslow’s Hierarchy of Needs, while at the same time unleashing your potential in the scholarly research. Do not forget that life is a treasure and that its contents continue to be a mystery, thus, your journey of discovery through research has not come to an end but rather, is just the beginning. Enjoy life through your continuous discovery of knowledge, and spearhead innovation while you are at it. Make your alma mater proud through this continuous discovery as alumni of UiTM. As you soar upwards in your career, my advice will be to continuously be humble and ‘plant’ your feet firmly on the ground. Congratulations once again and may you carry UiTM as ‘Sentiasa di Hatiku’. Tan Sri Dato’ Sri Prof Ir Dr Sahol Hamid Abu Bakar, FASc, PEng Vice Chancellor Universiti Teknologi MAR

Health monitoring of pavement systems using smart sensing technologies

Pavement undergoes a process of deterioration resulting from repeated traffic and/or environmental loading. By detecting pavement distress and damage early enough, it is possible for transportation agencies to develop more effective pavement maintenance and rehabilitation programs and thereby produce significant cost and time saving. Structural Health Monitoring (SHM) has been conceived as a systematic method for assessing the structural state of pavement infrastructure systems and documenting their condition. Over the past several years, this process has traditionally been accomplished through the use of wired sensors embedded in bridge and highway pavement. However, the use of wired sensors has limitations for long-term SHM and presents other associated cost and safety concerns. Recently, Micro-Electromechanical Systems (MEMS) and Nano-Electromechanical Systems (NEMS) have emerged as advanced/smart-sensing technologies with potential for cost-effective and long-term SHM. To this effect, a study has thus been initiated to evaluate the off-the-shelf MEMS sensors and wireless sensors, identify their limitations, and demonstrate how the acquired sensor data can be utilized to monitor and assess concrete pavement behavior. The feasibility of implementing a wireless communication system into a MEMS sensor was also investigated. Off-the-shelf MEMS sensors and wireless sensors were deployed in a newly constructed concrete highway pavement. During the monitoring period, the temperature, moisture, and strain profiles were obtained and analyzed. The monitored data captured the effects of daily and seasonal weather changes on concrete pavement, especially, early-age curling and warping behavior of concrete pavement. These sensors, however, presented issues for long-term operation, so to improve performance, a ZigBee protocol-based wireless communication system was implemented for the MEMS sensors. By synthesizing knowledge and experience gained from literature review, field demonstrations, and implementation of wireless systems, issues associated with sensor selection, sensor installation, sensor packaging to prevent damage from road construction, and monitoring for concrete pavement SHM are summarized. The requirements for achieving Smart Pavement SHM are then explored to develop a conceptual design of smart health monitoring of both highway and airport pavement systems for next-generation pavement SHM. A cost evaluation was also performed for traditional as well as MEMS sensors and other potential smart technologies for SHM

Modifying Commercial RFID Tags using Polydimethylsiloxane based Polymers for Sensing Purposes.

In the last decade, RFID sensing has grown rapidly. Passive RFID tags are attractive due to their low cost, theoretically infinite lifespans, small form factor and the ability to be read without a line of sight required. This has resulted in an enormous increase in research and commercial interest, with RFID sensing growing at an ever expanding rate. Previous RFID sensing has relied upon exploiting the reader side of RFID systems, or incorporating bespoke sensors into RFID systems. Newer classes of sensing tags now allow for useable sensing information to be provided by the tag antenna in the form of a sensor code that relates to a stimuli affecting the tag. A popular research avenue for RFID has been utilising stimuli responsive materials. Using stimuli responsive polymers and other materials has previously relied upon exploiting the analogue changes that result when the stimuli responsive material is affected by an analyte of interest. The primary advantage of using stimuli responsive materials over bespoke sensing components is that the simpler components can be utilised. Nowadays, commercial sensing tags can be purchased for as little as £2.75, that can provide digital information about environmental conditions. Whilst dedicated sensors for other analytes would be expected to have a higher cost, incorporating polymeric materials into lower cost sensors and repurposing them to sense a range of analytes presents an attractive alternative. A commercially available RFMicron RFM-2100 AER moisture sensing tag was modified with polydimethylsiloxane (PDMS) to allow for sensing of aqueous electrolytes of variable concentration. Coating the tag with the hydrophobic layer also allowed for the system to return to be reusable. The system also demonstrated the ability measure the relative amount of water (or alcohol) in water/alcohol mixes. A two part reactive silicone cross-linked polymer was also investigated for the purpose of repurposing the tag to be used as a pH sensor, but was found not to produce enough (if any) changes in response with variable pH. Following this work, a preliminary investigation showed the potential for a PDMS/PANI (polyaniline) composite was tested as a pH responsive coating for the RFMicron RFM2100 AER. The system was capable of measuring 5 distinct ranges of pH, but only on the first use of the system, as after this the system became incapable of measuring pH changes aside from those associated with the large change in dielectric properties of extremely low pH solutions

RFID Technologies in Intelligent Medical Applications

This thesis examines RFID-technologies as a part of the development of intelligent medical applications. In this context the intelligence is interpreted as a property of a system that is more automatic, safe or efficient due to solutions achieved by information technology. RFID-technologies offer a wide range of possibilities for both containing and acquiring information. With the help of RFID-systems information such as the count, location, or status of hospital equipment can be obtained and monitored without the need for line of sight. In this thesis the task of applying RFID-technologies to achieve more intelligent medical applications is approached by researching the compatibility of all the known RFID-technologies at the moment of writing. However researches presented in this thesis are generally related to systems operating within the UHF-frequency band. The thesis describes the main characteristics of the four main RFID-technology standards. As this research is concentrated on the solutions specialized in hospital environments, the compliances to such a setting are highlighted from the research papers undergone in this thesis. Functionalities that are considered to be useful in an intelligent hospital setting are presented in the literature study. Such functionalities include RFID-tags that are aware of their location and orientation, tags that carry user updatable data and even tags that update their data by themselves. After revising the RFID-technologies, a case-related research conducted for this thesis is presented. The research analyzes and estimates the saturation times of the carbon dioxide absorbers that are used in anesthesia machines. The measurements are conducted by multiple tests where environmental variables are changed to different known values and the results are recorded. The goal of the research is to find out if it is possible to predict the absorber behavior, and whether saving the information needed or the prediction can be done directly to the absorbers themselves. To predict saturation, lifetime and usability of the absorbers a formula is calculated, and the formula is evaluated based on the values measured. As a conclusion UHF-RFID-technology is evaluated to be most compatible to be used in the prototype for the case. In this thesis the RFID-technologies are evaluated to be an economical and functional solution for the monitoring of absorber state, and the case is agreed to be a convenient solution to begin the transformation to intelligent hospitals. /Kir1