Energy-efficient Wireless Analog Sensing for Persistent Underwater Environmental Monitoring

The design of sensors or "things" as part of the new Internet of Underwater Things (IoUTs) paradigm comes with multiple challenges including limited battery capacity, not polluting the water body, and the ability to track continuously phenomena with high temporal/spatial variability. We claim that traditional digital sensors are incapable to meet these demands because of their high power consumption, high complexity (cost), and the use of non-biodegradable materials. To address the above challenges, we propose a novel architecture consisting of a sensing substrate of dense analog biodegradable sensors over which lies the traditional Wireless Sensor Network (WSN). The substrate analog biodegradable sensors perform Shannon mapping (a data-compression technique) using just a single Field Effect Transistor (FET) without the need for power-hungry Analog-to-Digital Converters (ADCs) resulting in much lower power consumption, complexity, and the ability to be powered using only sustainable energy-harvesting techniques. A novel and efficient decoding technique is also presented. Both encoding/decoding techniques have been verified via Spice and MATLAB simulations accounting for underwater acoustic channel variations.Comment: 5 pages, IEEE UComms 201

Towards Stable Electrochemical Sensing for Wearable Wound Monitoring

Wearable biosensing has the tremendous advantage of providing point-of-care diagnosis and convenient therapy. In this research, methods to stabilize the electrochemical sensing response from detection of target biomolecules, Uric Acid (UA) and Xanthine, closely linked to wound healing, have been investigated. Different kinds of materials have been explored to address such detection from a wearable, healing platform. Electrochemical sensing modalities have been implemented in the detection of purine metabolites, UA and Xanthine, in the physiologically relevant ranges of the respective biomarkers. A correlation can be drawn between the concentrations of these bio-analytes and wound severity, thus offering probable quantitative insights on wound healing progression. These insights attempt to contribute in reducing some impacts of the financial structure on the healthcare economy associated with wound-care. An enzymatic electrochemical sensing system was designed to provide quick response at a cost-effective, miniaturized scale. Robust enzyme immobilization protocols have assisted in preserving enzyme activity to offer stable response under relevant variations of temperature and pH, from normal. Increased hydrophilicity of the sensor surface using corona plasma, has assisted in improving conductivity, thus allowing for increased electroactive functionalization and loading across the substrate’s surface. Superior sensor response was attained from higher loading of nanomaterials (MWCNT/AuNP) and enzymes (UOx/XO) employed in detection. Potentiometric analyses of the nanomaterial modified enzymatic biosensors were conducted using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) modalities. Under relevant physiological conditions, the biosensor was noted to offer a variation in response between 10 % and 30 % within a week. Stable, reproducible results were obtained from repeated use of the biosensor over multiple days, also offering promise for continuous monitoring. Shelf life of the biosensor was noted to be more than two days with response retained by about 80 % thereafter. Secondary analyses have been performed utilizing the enzymatic biosensor to explore the feasibility of target biomarker detection from clinical extracts of different biofluids for wound monitoring. Biosensor response evaluation from the extracts of human wound exudate, and those obtained from perilesional and healthy skin, provided an average recovery between 107 % and 110 % with a deviation within (+/-) 6 %. Gradual decrease in response (10-20 %) was noted in detection from extracts further away from injury site. Increased accumulation of biofluids on the sensor surface was studied to explore sensor response stability as a function of sample volume. With a broad linear range of detection (0.1 nM – 7.3 mM) and detection limits lower than the physiological concentrations, this study has assessed the viability of stable wound monitoring under physiologically relevant conditions on a wearable platform

A Hybrid-Powered Wireless System for Multiple Biopotential Monitoring

Chronic diseases are the top cause of human death in the United States and worldwide. A huge amount of healthcare costs is spent on chronic diseases every year. The high medical cost on these chronic diseases facilitates the transformation from in-hospital to out-of-hospital healthcare. The out-of-hospital scenarios require comfortability and mobility along with quality healthcare. Wearable electronics for well-being management provide good solutions for out-of-hospital healthcare. Long-term health monitoring is a practical and effective way in healthcare to prevent and diagnose chronic diseases. Wearable devices for long-term biopotential monitoring are impressive trends for out-of-hospital health monitoring. The biopotential signals in long-term monitoring provide essential information for various human physiological conditions and are usually used for chronic diseases diagnosis. This study aims to develop a hybrid-powered wireless wearable system for long-term monitoring of multiple biopotentials. For the biopotential monitoring, the non-contact electrodes are deployed in the wireless wearable system to provide high-level comfortability and flexibility for daily use. For providing the hybrid power, an alternative mechanism to harvest human motion energy, triboelectric energy harvesting, has been applied along with the battery to supply energy for long-term monitoring. For power management, an SSHI rectifying strategy associated with triboelectric energy harvester design has been proposed to provide a new perspective on designing TEHs by considering their capacitance concurrently. Multiple biopotentials, including ECG, EMG, and EEG, have been monitored to validate the performance of the wireless wearable system. With the investigations and studies in this project, the wearable system for biopotential monitoring will be more practical and can be applied in the real-life scenarios to increase the economic benefits for the health-related wearable devices

Low-Cost Sensors and Biological Signals

Many sensors are currently available at prices lower than USD 100 and cover a wide range of biological signals: motion, muscle activity, heart rate, etc. Such low-cost sensors have metrological features allowing them to be used in everyday life and clinical applications, where gold-standard material is both too expensive and time-consuming to be used. The selected papers present current applications of low-cost sensors in domains such as physiotherapy, rehabilitation, and affective technologies. The results cover various aspects of low-cost sensor technology from hardware design to software optimization

Low-power Wearable Healthcare Sensors

Advances in technology have produced a range of on-body sensors and smartwatches that can be used to monitor a wearer’s health with the objective to keep the user healthy. However, the real potential of such devices not only lies in monitoring but also in interactive communication with expert-system-based cloud services to offer personalized and real-time healthcare advice that will enable the user to manage their health and, over time, to reduce expensive hospital admissions. To meet this goal, the research challenges for the next generation of wearable healthcare devices include the need to offer a wide range of sensing, computing, communication, and human–computer interaction methods, all within a tiny device with limited resources and electrical power. This Special Issue presents a collection of six papers on a wide range of research developments that highlight the specific challenges in creating the next generation of low-power wearable healthcare sensors

Correlating the Effect of Dynamic Variability in the Sensor Environment on Sensor Design

This dissertation studies the effect of biofluid dynamics on the electrochemical response of a wearable sensor for monitoring of chronic wounds. The research investigates various dynamic in vivo parameters and correlates them with experimentally measured behavior with wound monitoring as a use case. Wearable electrochemical biosensors suffer from several unaddressed challenges, like stability and sensitivity, that need to be resolved for obtaining accurate data. One of the major challenges in the use of these sensors is continuous variation in biofluid composition. Wound healing is a dynamic process with wound composition changing continuously. This dissertation investigates the effects of several in vivo biochemical and environmental parameters on the sensor response to establish actionable correlations. Real-time assessment of wound healing was carried out through longitudinal monitoring of uric acid and other wound fluid characteristics. A textile sensor was designed using a simple fabrication approach combining conductive inks with a polymeric substrate, for conformal contact with the wound bed. A −1 cm−2, establishing the applicability of the sensor for measurements in the physiologically relevant range. The sensor was also found to be stable for a period of 3 days when subjected to physiological and elevated temperatures (37oC and 40oC) confirming its relevance for long-term monitoring. A direct correlation between sensor response and the dynamic parameters was seen, with the results showing a ~20% deviation from the accurate UA reading. The results confirmed that as a consequence of these parameters temporally changing in the wound environment, the sensor response will be altered. The work develops mathematical models correlating this effect on sensor response to allow for real-time sensor calibration. The clinical validation studies established the feasibility of UA measurement by the developed electrochemical sensor and derive correlations between the wound chronicity and UA levels. The protocols developed in this work for the design, fabrication, and calibration of the sensor to correct for the dynamic in vivo behavior can be extended to any wearable sensor for improved accuracy

Nanochips and medical applications

Ο όρος «νανοτσιπ» αναφέρεται σε ένα ολοκληρωμένο κύκλωμα (τσιπ) με νανοϋλικά και δομές στη νανοκλίμακα (1-100nm). Ένα ολοκληρωμένο κύκλωμα είναι μια συλλογή ηλεκτρονικών εξαρτημάτων, όπως τρανζίστορ, δίοδοι, πυκνωτές και αντιστάσεις. Τα σημερινά τρανζίστορ είναι στη νανοκλίμακα, αλλά μπορούν να τροποποιηθούν με νανοδομές για την κατασκευή βιοαισθητήρων που μπορούν να πραγματοποιούν ανίχνευση βιομορίων, όπως ιόντα, μόρια DNA, αντισώματα και αντιγόνα με μεγάλη ευαισθησία. Υλικά και Μέθοδοι: Πραγματοποιήθηκε συστηματική αναζήτηση βιβλιογραφίας με χρήση των ηλεκτρονικών βάσεων δεδομένων PubMed, Google Scholar και Scopus για την ανάπτυξη και χρήση νανοτσίπ σε ιατρικές εφαρμογές. Για τον προσδιορισμό των σχετικών εργασιών, τα κριτήρια συμπερίληψης αναφέρονται σε άρθρα στην αγγλική γλώσσα, άρθρα βιβλιογραφικού περιεχομένου ή/και έρευνών. Τα κριτήρια αποκλεισμού ήταν άρθρα εφημερίδων, περιλήψεις συνεδρίων και επιστολές. Αποτελέσματα: Τεχνικές in-vivo και in-vitro έχουν χρησιμοποιηθεί για την ανίχνευση μορίων DNA, ιόντων, αντισωμάτων, σημαντικών πρωτεϊνών και καρκινικών δεικτών, όχι μόνο από δείγματα αίματος αλλά και από ιδρώτα, σάλιο και άλλα βιολογικά υγρά. Διαγνωστική εφαρμογή των νανοτσίπ αποτελεί και η ανίχνευση πτητικών οργανικών ενώσεων μέσω τεστ εκπνεόμενης αναπνοής. Υπάρχουν και αρκετές θεραπευτικές εφαρμογές αυτών των συσκευών ημιαγωγών όπως τσιπ διασύνδεσης εγκεφάλου-υπολογιστή για παραλυτικές ή επιληπτικές καταστάσεις, κατασκευή «βιονικών» οργάνων όπως τεχνητός αμφιβληστροειδής, τεχνητό δέρμα και ρομποτικά προθετικά άκρα για ακρωτηριασμένους ή ρομποτική χειρουργική. Συμπέρασμα: Η χρήση των νανοτσίπ στην ιατρική είναι ένας αναδυόμενος τομέας με αρκετές θεραπευτικές εφαρμογές όπως η διάγνωση, η παρακολούθηση της υγείας και της φυσικής κατάστασης και η κατασκευή «βιονικών» οργάνων.Background: The term “nanochip” pertains to an integrated circuit (chip) with nanomaterials and components in the nano-dimension (1-100nm). An integrated circuit is essentially a collection of electronic components, like transistors, diodes, capacitors, and resistors. Current transistors are in the nanoscale but can also be modified with nanostructures like nanoribbons and nanowires to manufacture biosensors that can perform label-free, ultrasensitive detection of biomolecules like ions, DNA molecules, antibodies and antigens. Materials and Methods: A systematic literature search was conducted using the electronic databases PubMed, Google Scholar and Scopus for the development and use of nanochips in medical applications. For the identification of relevant papers, the inclusion criteria referred to articles in the English language, review and/or research articles. The exclusion criteria were newspaper articles, conference abstracts and letters. Results: In-vivo and In-vitro techniques have been used for detection of DNA molecules, ions, antibodies, important proteins, and tumor markers, not only from blood samples but also from sweat, saliva and other biological fluids. Another diagnostic application of nanochips is detection of volatile organic compounds via a breath test. There are also several therapeutic applications of these semiconductor devices like brain-computer interface chips for paralytic or epileptic conditions, manufacture of “bionic” organs like artificial retinas, artificial skin and robotic prostheses for amputees or robotic surgery. Conclusion: The use of nanochips in medicine is an emerging field with several therapeutic applications like diagnostics, health and fitness monitoring, and manufacture of “bionic” organs

Innovative IoT Solutions and Wearable Sensing Systems for Monitoring Human Biophysical Parameters: A Review

none3noDigital and information technologies are heavily pervading several aspects of human activities, improving our life quality. Health systems are undergoing a real technological revolution, radically changing how medical services are provided, thanks to the wide employment of the Internet of Things (IoT) platforms supporting advanced monitoring services and intelligent inferring systems. This paper reports, at first, a comprehensive overview of innovative sensing systems for monitoring biophysical and psychophysical parameters, all suitable for integration with wearable or portable accessories. Wearable devices represent a headstone on which the IoT-based healthcare platforms are based, providing capillary and real-time monitoring of patient’s conditions. Besides, a survey of modern architectures and supported services by IoT platforms for health monitoring is presented, providing useful insights for developing future healthcare systems. All considered architectures employ wearable devices to gather patient parameters and share them with a cloud platform where they are processed to provide real-time feedback. The reported discussion highlights the structural differences between the discussed frameworks, from the point of view of network configuration, data management strategy, feedback modality, etc.Article Number: 1660openRoberto De Fazio; Massimo De Vittorio; Paolo ViscontiDE FAZIO, Roberto; DE VITTORIO, Massimo; Visconti, Paol