Tissue Viability Monitoring: a Multi-Sensor Wearable Platform Approach

Health services worldwide are seeking ways to improve patient care for amputees suffering from diabetes, and at the same time reduce costs. The monitoring of residual limb temperature, interface pressure and gait can be a useful indicator of tissue viability in lower limb amputees especially to predict the occurrence of pressure ulcers. This is further exacerbated by elevated temperatures and humid micro environment within the prosthesis which encourages the growth of bacteria and skin breakdown. Wearable systems for prosthetic users have to be designed such that the sensors are minimally obtrusive and reliable enough to faithfully record movement and physiological signals. A mobile sensor platform has been developed for use with the lower limb prosthetic users. This system uses an Arduino board that includes sensors for temperature, gait, orientation and pressure measurements. The platform transmits sensor data to a central health authority database server infrastructure through the Bluetooth protocol at a suitable sampling rate. The data-sets recorded using these systems are then processed using machine learning algorithms to extract clinically relevant information from the data. Where a sensor threshold is reached a warning signal can be sent wirelessly together with the relevant data to the patient and appropriate medical personnel. This knowledge is also useful in establishing biomarkers related to a possible deterioration in a patient’s health or for assessing the impact of clinical interventions

A Triple-Mode Flexible E-Skin Sensor Interface for Multi-Purpose Wearable Applications

This study presents a flexible wireless electronic skin (e-skin) sensor system that includes a multi-functional sensor device, a triple-mode reconfigurable readout integrated circuit (ROIC), and a mobile monitoring interface. The e-skin device's multi-functionality is achieved by an interlocked micro-dome array structure that uses a polyvinylidene fluoride and reduced graphene oxide (PVDF/RGO) composite material that is inspired by the structure and functions of the human fingertip. For multi-functional implementation, the proposed triple-mode ROIC is reconfigured to support piezoelectric, piezoresistance, and pyroelectric interfaces through single-type e-skin sensor devices. A flexible system prototype was developed and experimentally verified to provide various wireless wearable sensing functions-including pulse wave, voice, chewing/swallowing, breathing, knee movements, and temperature-while their real-time sensed data are displayed on a smartphone

Sensing Systems for Respiration Monitoring: A Technical Systematic Review

Respiratory monitoring is essential in sleep studies, sport training, patient monitoring, or health at work, among other applications. This paper presents a comprehensive systematic review of respiration sensing systems. After several systematic searches in scientific repositories, the 198 most relevant papers in this field were analyzed in detail. Different items were examined: sensing technique and sensor, respiration parameter, sensor location and size, general system setup, communication protocol, processing station, energy autonomy and power consumption, sensor validation, processing algorithm, performance evaluation, and analysis software. As a result, several trends and the remaining research challenges of respiration sensors were identified. Long-term evaluations and usability tests should be performed. Researchers designed custom experiments to validate the sensing systems, making it difficult to compare results. Therefore, another challenge is to have a common validation framework to fairly compare sensor performance. The implementation of energy-saving strategies, the incorporation of energy harvesting techniques, the calculation of volume parameters of breathing, or the effective integration of respiration sensors into clothing are other remaining research efforts. Addressing these and other challenges outlined in the paper is a required step to obtain a feasible, robust, affordable, and unobtrusive respiration sensing system

Wearable mobile sensor and communication platform for the in-situ monitoring of lower limb health in amputees

Monitoring the health of a residual limb in prosthesis is key to detect early signs of tissue injury, and could improve patient quality of life. However, monitoring at skin level could induce possible discomfort and irritation, making the skin susceptible for breakdown. The use of non-invasive sensor technologies within the flexible liner of the prosthetic device can alleviate these issues. The rehabilitation of lower limb prosthesis wearers can be greatly improved by a reliable continuous monitoring system that can alert both the user and health authority by early warning of the development of tissue damage. In this work, we have created a wearable sensor platform for lower limb amputees that is capable of gathering data from the sensors (placed on the elastomer), and store and transmit to a central health database, for the purpose of analyzing it. This paper explores the architecture used, as well as some of the challenges encountered when handling such quantities of data as experienced in this project

Lead-free piezoceramics - Where to move on?

Lead-free piezoceramics aiming at replacing the market-dominant lead-based ones have been extensively searched for more than a decade worldwide. Some noteworthy outcomes such as the advent of commercial products for certain applications have been reported, but the goal, i.e., the invention of a lead-free piezocermic, the performance of which is equivalent or even superior to that of PZT-based piezoceramics, does not seem to be fulfilled yet. Nevertheless, the academic effort already seems to be culminated, waiting for a guideline to a future research direction. We believe that a driving force for a restoration of this research field needs to be found elsewhere, for example, intimate collaborations with related industries. For this to be effectively realized, it would be helpful for academic side to understand the interests and demands of the industry side as well as to provide the industry with new scientific insights that would eventually lead to new applications. Therefore, this review covers some of the issues that are to be studied further and deeper, so-to-speak, lessons from the history of piezoceramics, and some technical issues that could be useful in better understanding the industry demands. As well, the efforts made in the industry side will be briefly introduced for the academic people to catch up with the recent trends and to be guided for setting up their future research direction effectively.ope

An Energy-Autonomous Smart Shirt employing wearable sensors for Users’ Safety and Protection in Hazardous Workplaces

none4siWearable devices represent a versatile technology in the IoT paradigm, enabling noninvasive and accurate data collection directly from the human body. This paper describes the development of a smart shirt to monitor working conditions in particularly dangerous workplaces. The wearable device integrates a wide set of sensors to locally acquire the user’s vital signs (e.g., heart rate, blood oxygenation, and temperature) and environmental parameters (e.g., the concentration of dangerous gas species and oxygen level). Electrochemical gas-monitoring modules were designed and integrated into the garment for acquiring the concentrations of CO, O2, CH2O, and H2S. The acquired data are wirelessly sent to a cloud platform (IBM Cloud), where they are displayed, processed, and stored. A mobile application was deployed to gather data from the wearable devices and forward them toward the cloud application, enabling the system to operate in areas where aWiFi hotspot is not available. Additionally, the smart shirt comprises a multisource harvesting section to scavenge energy from light, body heat, and limb movements. Indeed, the wearable device integrates several harvesters (thin-film solar panels, thermoelectric generators (TEGs), and piezoelectric transducers), a low-power conditioning section, and a 380 mAh LiPo battery to accumulate the recovered charge. Field tests indicated that the harvesting section could provide up to 216 mW mean power, fully covering the power requirements (P = 1.86 mW) of the sensing, processing, and communication sections in all considered conditions (3.54 mW in the worst-case scenario). However, the 380 mAh LiPo battery guarantees about a 16-day lifetime in the complete absence of energy contributions from the harvesting section.Special Issue “Innovative Materials, Smart Sensors and IoT-based Electronic Solutions for Wearable Applications”, https://www.mdpi.com/journal/applsci/special_issues/Materials_Sensors_Electronic_Solutions_Wearable_ApplicationsopenRoberto De Fazio, Abdel-Razzak Al-Hinnawi, Massimo De Vittorio, Paolo ViscontiDE FAZIO, Roberto; Al-Hinnawi, Abdel-Razzak; DE VITTORIO, Massimo; Visconti, Paol

New generation of interactive platforms based on novel printed smart materials

Programa doutoral em Engenharia Eletrónica e de Computadores (área de Instrumentação e Microssistemas Eletrónicos)The last decade was marked by the computer-paradigm changing with other digital devices suddenly becoming available to the general public, such as tablets and smartphones. A shift in perspective from computer to materials as the centerpiece of digital interaction is leading to a diversification of interaction contexts, objects and applications, recurring to intuitive commands and dynamic content that can proportionate more interesting and satisfying experiences. In parallel, polymer-based sensors and actuators, and their integration in different substrates or devices is an area of increasing scientific and technological interest, which current state of the art starts to permit the use of smart sensors and actuators embodied within the objects seamlessly. Electronics is no longer a rigid board with plenty of chips. New technological advances and perspectives now turned into printed electronics in polymers, textiles or paper. We are assisting to the actual scaling down of computational power into everyday use objects, a fusion of the computer with the material. Interactivity is being transposed to objects erstwhile inanimate. In this work, strain and deformation sensors and actuators were developed recurring to functional polymer composites with metallic and carbonaceous nanoparticles (NPs) inks, leading to capacitive, piezoresistive and piezoelectric effects, envisioning the creation of tangible user interfaces (TUIs). Based on smart polymer substrates such as polyvinylidene fluoride (PVDF) or polyethylene terephthalate (PET), among others, prototypes were prepared using piezoelectric and dielectric technologies. Piezoresistive prototypes were prepared with resistive inks and restive functional polymers. Materials were printed by screen printing, inkjet printing and doctor blade coating. Finally, a case study of the integration of the different materials and technologies developed is presented in a book-form factor.A última década foi marcada por uma alteração do paradigma de computador pelo súbito aparecimento dos tablets e smartphones para o público geral. A alteração de perspetiva do computador para os materiais como parte central de interação digital levou a uma diversificação dos contextos de interação, objetos e aplicações, recorrendo a comandos intuitivos e conteúdos dinâmicos capazes de tornarem a experiência mais interessante e satisfatória. Em simultâneo, sensores e atuadores de base polimérica, e a sua integração em diferentes substratos ou dispositivos é uma área de crescente interesse científico e tecnológico, e o atual estado da arte começa a permitir o uso de sensores e atuadores inteligentes perfeitamente integrados nos objetos. Eletrónica já não é sinónimo de placas rígidas cheias de componentes. Novas perspetivas e avanços tecnológicos transformaram-se em eletrónica impressa em polímeros, têxteis ou papel. Neste momento estamos a assistir à redução da computação a objetos do dia a dia, uma fusão do computador com a matéria. A interatividade está a ser transposta para objetos outrora inanimados. Neste trabalho foram desenvolvidos atuadores e sensores e de pressão e de deformação com recurso a compostos poliméricos funcionais com tintas com nanopartículas (NPs) metálicas ou de base carbónica, recorrendo aos efeitos capacitivo, piezoresistivo e piezoelétrico, com vista à criação de interfaces de usuário tangíveis (TUIs). Usando substratos poliméricos inteligentes tais como fluoreto de polivinilideno (PVDF) ou politereftalato de etileno (PET), entre outos, foi possível a preparação de protótipos de tecnologia piezoelétrica ou dielétrica. Os protótipos de tecnologia piezoresistiva foram feitos com tintas resistivas e polímeros funcionais resistivos. Os materiais foram impressos por serigrafia, jato de tinta, impressão por aerossol e revestimento de lâmina doctor blade. Para terminar, é apresentado um caso de estudo da integração dos diferentes materiais e tecnologias desenvolvidos sob o formato de um livro.This project was supported by FCT – Fundação para a Ciência e a Tecnologia, within the doctorate grant with reference SFRH/BD/110622/2015, by POCH – Programa Operacional Capital Humano, and by EU – European Union