Wearable and Miniaturized Sensor Technologies for Personalized and Preventive Medicine

The unprecedented medical achievements of the last century have dramatically improved our quality of life. Today, the high cost of many healthcare approaches challenges their long‐term financial sustainability and translation to a global scale. The convergence of wearable electronics, miniaturized sensor technologies, and big data analysis provides novel opportunities to improve the quality of healthcare while decreasing costs by the very early stage detection and prevention of fatal and chronic diseases. Here, some exciting achievements, emerging technologies, and standing challenges for the development of non‐invasive personalized and preventive medicine devices are discussed. The engineering of wire‐ and power‐less ultra‐thin sensors on wearable biocompatible materials that can be placed on the skin, pupil, and teeth is reviewed, focusing on common solutions and current limitations. The integration and development of sophisticated sensing nanomaterials are presented with respect to their performance, showing exemplary implementations for the detection of ultra‐low concentrations of biomarkers in complex mixtures such as the human sweat and breath. This review is concluded by summarizing achievements and standing challenges with the aim to provide directions for future research in miniaturized medical sensor technologies.     

Pervasive, secure access to a hierarchical sensor-based healthcare monitoring architecture in wireless heterogeneous networks

This study presents a healthcare monitoring architecture coupled with wearable sensor systems and an environmental sensor network for monitoring elderly or chronic patients in their residence. The wearable sensor system, built into a fabric belt, consists of various medical sensors that collect a timely set of physiological health indicators transmitted via low energy wireless communication to mobile computing devices. Three application scenarios are implemented using the proposed network architecture. The group-based data collection and data transmission using the ad hoc mode promote outpatient healthcare services for only one medical staff member assigned to a set of patients. Adaptive security issues for data transmission are performed based on different wireless capabilities. This study also presents a monitoring application prototype for capturing sensor data from wireless sensor nodes. The implemented schemes were verified as performing efficiently and rapidly in the proposed network architecture.     

A type of healthcare system based on intelligent wireless sensor networks

A healthcare system based on wireless sensor networks (WSNs) is proposed to improve the quality of medical care in hospital or even at home. Structures of the wearable healthcare node, wireless multimedia node as well as the gateway in this system are described in detail. Moreover, a type of localization method for patients and an energy-efficient transmission strategy are put forward as well. Experimental results show that this system performs well on data transmission and information processing.     

Conductive Hierarchical Hairy Fibers for Highly Sensitive,Stretchable, and Water‐Resistant Multimodal Gesture‐Distinguishable Sensor,VR Applications

Conductive fibers, which are highly adaptable to the morphologies of the human body, are attractive for the development of wearable systems, smart clothing, and textronics to detect various biological signals and human motions. A fiber‐based conductive sensor interconnected with hierarchical microhairy architectures, exhibiting remarkable stretchability (<200%) and sensitivity for various stimuli (pressure, stretching, and bending), is developed. For distinguishability of multiple gestures, two hierarchical hairy conductive fibers are twisted to fabricate a fiber‐type sensor, which monitors distinct waveforms of electrical signals retrieved from pressure, stretching, and bending. This sensor is highly robust under repeated appliances of external stimuli over multiple cyclic tests of various modes (<2200 cycles for each stimulus). Upon formation of a self‐assembled monolayer, it exhibits stable performance even under wet conditions. For practical applications, this sensor can be weaved into a smart glove to demonstrate a pressure and gesture‐discernible wearable controller for virtual reality (VR) interface, shedding light on advances in wearable electronics with medical and healthcare functionalities and VR systems.     

Wireless technologies for telemedicine

Wireless telemedicine is a new and evolving area in telemedical and telecare systems. Healthcare personnel require realtime access to accurate patient data, including clinical histories, treatments, medication, tests, laboratory results and insurance information. With large-scale wireless networks and mobile computing solutions, such as cellular 3G, Wi-Fi mesh and WiMAX, healthcare personnal can tap into vital information anywhere and at any time within the healthcare networks. The recent introduction of pervasive computing, consisting of radio frequency identification (RFID), Bluetooth, ZigBee, and wireless sensor networks, further extends the potential for exploitation of wireless telecommunications and its integration into new mobile healthcare delivery systems. In this paper, snapshots of current uses and future trends of various wireless communications in the healthcare domain are highlighted. Special attention is given to the challenges of a telemedicine environment equipped with different wireless technologies and how the resulting issues might be addressed in medical services integration to provide flexible, convenient and economical medical monitoring, consultation and healthcare.     

Mimicking Human and Biological Skins for Multifunctional Skin Electronics

Electronic skin (e‐skin) technology is an exciting frontier to drive the next generation of wearable electronics owing to its high level of wearability, enabling high accuracy to harvest information of users and their surroundings. Recently, biomimicry of human and biological skins has become a great inspiration for realizing novel wearable electronic systems with exceptional multifunctionality as well as advanced sensory functions. This review covers and highlights bioinspired e‐skins mimicking perceptive features of human and biological skins. In particular, five main components in tactile sensation processes of human skin are individually discussed with recent advances of e‐skins that mimic the unique sensing mechanisms of human skin. In addition, diverse functionalities in user‐interactive, skin‐attachable, and ultrasensitive e‐skins are introduced with the inspiration from unique architectures and functionalities, such as visual expression of stimuli, reversible adhesion, easy deformability, and camouflage, in biological skins of natural creatures. Furthermore, emerging wearable sensor systems using bioinspired e‐skins for body motion tracking, healthcare monitoring, and prosthesis are described. Finally, several challenges that should be considered for the realization of next‐generation skin electronics are discussed with recent outcomes for addressing these challenges.     

Feasibility and performance evaluation of a 6LoWPAN‐enabled platform for ubiquitous healthcare monitoring

Technology has revolutionized medical practices by enabling more convenient and non‐intrusive monitoring of patient's health, leading to next generation ubiquitous healthcare (u‐healthcare). The exploitation of the Internet protocol version 6 addressing space along with the miniaturization of electronic devices has fostered providing interoperability and connectivity of wearable sensor devices in wireless body area networks to the Internet of Things. In this paper, we propose to integrate the IPv6 over low power wireless personal area network (6LoWPAN) to the u‐healthcare monitoring system architecture. The main objective is to study the feasibility of the 6LoWPAN‐enabled platform in real‐world scenarios dealing with medical data. The performance evaluation of this platform is carried out initially through simulations using OMNet++ and then supported by an experimental study using sensor motes and a customized micro‐computing unit. Performance metrics such as throughput, end‐to‐end delay, packet error rate, and energy consumption are investigated under acute health conditions, where patient's health information has to be sent continuously and at maximum rate to the care provider. The obtained results show that the proposed 6LoWPAN solution fulfills the main quality of service requirements of u‐healthcare applications. Copyright © 2015 John Wiley & Sons, Ltd.     

Smart Clothing: Connecting Human with Clouds and Big Data for Sustainable Health Monitoring

Traditional wearable devices have various shortcomings, such as uncomfortableness for long-term wearing, and insufficient accuracy, etc. Thus, health monitoring through traditional wearable devices is hard to be sustainable. In order to obtain healthcare big data by sustainable health monitoring, we design “Smart Clothing”, facilitating unobtrusive collection of various physiological indicators of human body. To provide pervasive intelligence for smart clothing system, mobile healthcare cloud platform is constructed by the use of mobile internet, cloud computing and big data analytics. This paper introduces design details, key technologies and practical implementation methods of smart clothing system. Typical applications powered by smart clothing and big data clouds are presented, such as medical emergency response, emotion care, disease diagnosis, and real-time tactile interaction. Especially, electrocardiograph signals collected by smart clothing are used for mood monitoring and emotion detection. Finally, we highlight some of the design challenges and open issues that still need to be addressed to make smart clothing ubiquitous for a wide range of applications.     

Flexible energy storage devices for wearable bioelectronics

With the growing market of wearable devices for smart sensing and personalized healthcare applications,energy stor-age devices that ensure stable power supply and can be constructed in flexible platforms have attracted tremendous research in-terests.A variety of active materials and fabrication strategies of flexible energy storage devices have been intensively studied in recent years,especially for integrated self-powered systems and biosensing.A series of materials and applications for flex-ible energy storage devices have been studied in recent years.In this review,the commonly adopted fabrication methods of flex-ible energy storage devices are introduced.Besides,recent advances in integrating these energy devices into flexible self-powered systems are presented.Furthermore,the applications of flexible energy storage devices for biosensing are summar-ized.Finally,the prospects and challenges of the self-powered sensing system for wearable electronics are discussed.     

Temporal Accountability and Anonymity in Medical Sensor Networks

The increasing number of elderly patients in the world has lead to various new appliances and technologies in the modern tele-healthcare platform. One such application is the medical sensor network (MSN). In this application, patients are deployed with certain medical sensors and wearable devices and are remotely monitored by professionals. Thus, seeing a doctor in person is no longer the only option for those in need of medical care. Since it is also an economical way to reduce healthcare costs and save medical resources, we expect a robust, reliable, and scalable MSN in the near future. However, the time signal and temporal history in the current MSN are vulnerable due to unsecured infrastructure and transmission strategies. Meanwhile, the MSN may leak patients’ identifications or other sensitive information that violates personal privacy. To make sure that the critical time signal is accountable, we propose a new architecture for the MSN that is capable of temporal accountability. In addition, it also preserves privacy ability via a Crowds anonymous system. The analysis results clearly indicate the advantages of being our proposed methods in terms of low-cost and reliable and having scalable features.     

A wearable point-of-care system for home use that incorporates plug-and-play and wireless standards.

A point-of-care system for continuous health monitoring should be wearable, easy to use, and affordable to promote patient independence and facilitate acceptance of new home healthcare technology. Reconfigurability, interoperability, and scalability are important. Standardization supports these requirements, and encourages an open market where lower product prices result from vendor competition. This paper first discusses candidate standards for wireless communication, plug-and-play device interoperability, and medical information exchange in point-of-care systems. It then addresses the design and implementation of a wearable, plug-and-play system for home care which adopts the IEEE 1073 Medical Information Bus (MIB) standards, and uses Bluetooth as the wireless communication protocol. This standards-based system maximizes user mobility by incorporating a three-level architecture populated by base stations, wearable data loggers, and wearable sensors. Design issues include the implementation of the MIB standards on microcontroller-driven embedded devices, low power consumption, wireless data exchange, and data storage and transmission in a reconfigurable body-area network.     

Implementation of security policy for clinical information systems over wireless sensor networks

Various healthcare areas such as diagnosis, surgery, intensive care and treatment, and patient monitoring in general, would greatly benefit from light, autonomous devices which can be unobtrusively mounted on the patient’s body in order to monitor and report health-relevant variables to an interconnection device in the vicinity. This interconnection device should be able to connect to access points at different locations within the healthcare institution. In this manner, health-relevant measurements can be forwarded to the central medical database and stored therein. In this scenario, integrity and privacy of personal medical data is of utmost importance. In this paper we address the networking and security architecture of a healthcare information system comprised of patients’ personal sensor networks, department/room networks, hospital network, and medical databases. We discuss confidentiality and integrity policies for clinical information systems and propose the feasible enforcement mechanisms over the wireless hop. We also compare two candidate technologies, IEEE 802.15.1 and IEEE 802.15.4, from the aspect of resilience to jamming and denial-of-service attacks.     

Flexible Hybrid Sensor Systems with Feedback Functions

Skin-like wearable sensors are regarded as key technologies toward home-based healthcare, human–machine interfaces, robotics, prostheses, and enhanced augmented/virtual reality (AR/VR). Inspired by human somatosensory functions, artificial sensory feedback systems play vital roles in shaping interactions with complex environments and timely decision-making. This study presents an overview of recent advances in feedback-driven, closed-loop skin-inspired flexible sensor systems that make use of emerging functional nanomaterials and elaborate structures. Drawing on feedback solutions, four categories of sensor systems are highlighted, which include prosthesis- and AR/VR-based human–machine interfaces, smartphone-based approaches for point-of-care detection, and smart wearable displays for direct signal visualizations. Furthermore, the progress of machine learning on the reliable recognition of massive quantities of signals generated by flexible sensor networks is briefly discussed. The state-of-the-art hybrid sensor techniques, along with other emerging strategies, will enable total sensory feedback loop systems to be developed for next-generation electronic skins.     

Security issues of wireless sensor networks in healthcare applications

The emergence of wireless sensor networks (WSNs) in healthcare applications is gaining momentum through the increasing array of wearable vital sign sensors and location tags which can track both healthcare personnel and patient status/ location continuously in real-time mode. Despite the increased range of potential application frameworks — ranging from pre-hospital, in-hospital, ambulatory and home monitoring, to long-term database collection for longitudinal trend analysis — the security gap between existing WSN designs and the requirements of medical applications remains unresolved. Generally, WSN devices are extremely limited in terms of power, computation, and communication. They are often deployed in accessible areas, thus increasing security vulnerabilities. The dynamic ad hoc topology, multicast transmission, location awareness, critical data prioritisation, and co-ordination of diverse sensors of healthcare applications further exacerbate the security challenges. This paper presents an analysis of various WSN security mechanisms from the demanding perspective of healthcare applications, and considers the importance of security to the successful deployment of pervasive computing solutions in the healthcare industry.     

A Semantically Enriched Clinical Guideline Model Enabling Deployment in Heterogeneous Healthcare Environments

Clinical guidelines are developed to assist healthcare practitioners to make decisions on patient's medical problems, and as such they communicate with external applications to retrieve patient data to initiate medical actions through clinical workflows, and transmit information to alert/reminder systems. The interoperability problems in the healthcare information technology domain prevent wider deployment of clinical guidelines because each deployment requires a tedious custom adaptation phase. In this paper, we provide machine-processable mechanisms that express the semantics of clinical guideline interfaces so that automated processes can be used to access the clinical resources for guideline deployment and execution. To be able to deploy the semantically extended guidelines to healthcare settings semiautomatically, the underlying application's semantics must also be available. We describe how this can be achieved based on two prominent implementation technologies in use in the eHealth domain: integrating healthcare enterprise cross-enterprise document sharing integration profile for discovering and exchanging electronic healthcare records and Web service technology for interacting with the clinical workflows and wireless medical sensor devices. The system described in this paper is realized within the scope of the SAPHIRE Project.      

Smart Materials Enabled with Artificial Intelligence for Healthcare Wearables

Contemporary medicine suffers from many shortcomings in terms of successful disease diagnosis and treatment, both of which rely on detection capacity and timing. The lack of effective, reliable, and affordable detection and real-time monitoring limits the affordability of timely diagnosis and treatment. A new frontier that overcomes these challenges relies on smart health monitoring systems that combine wearable sensors and an analytical modulus. This review presents the latest advances in smart materials for the development of multifunctional wearable sensors while providing a bird's eye-view of their characteristics, functions, and applications. The review also presents the state-of-the-art on wearables fitted with artificial intelligence (AI) and support systems for clinical decision in early detection and accurate diagnosis of disorders. The ongoing challenges and future prospects for providing personal healthcare with AI-assisted support systems relating to clinical decisions are presented and discussed.     

Low‐cost wireless sensor networks for remote cardiac patients monitoring applications

One of today's most pressing matters in medical care is response time to patients in need. Scope of this research is to suggest a solution that would help reduce response time in emergency situations utilizing technologies of wireless sensor networks. The enhanced power efficiency, minimized production cost, condensed physical layout, and reduced wired connections present a much more proficient and simplified approach to the continuous monitoring of patients' physiological status. The proposed sensor network system is composed of wearable vital sign sensors and a workstation monitor. The wearable platforms are to be distributed to patients of concern. The wearable platforms can provide continuous electrocardiogram (ECG) monitoring by measuring electrical potentials between various points of the body using a galvanometer. They will then relay the ECG signals wirelessly to the workstation monitor. In addition to displaying the data, the workstation will also perform signal wavelet transformation for ECG characteristic extractions. Copyright © 2007 John Wiley & Sons, Ltd.     

Body Area Networks: A Survey

Advances in wireless communication technologies, such as wearable and implantable biosensors, along with recent developments in the embedded computing area are enabling the design, development, and implementation of body area networks. This class of networks is paving the way for the deployment of innovative healthcare monitoring applications. In the past few years, much of the research in the area of body area networks has focused on issues related to wireless sensor designs, sensor miniaturization, low-power sensor circuitry, signal processing, and communications protocols. In this paper, we present an overview of body area networks, and a discussion of BAN communications types and their related issues. We provide a detailed investigation of sensor devices, physical layer, data link layer, and radio technology aspects of BAN research. We also present a taxonomy of BAN projects that have been introduced/proposed to date. Finally, we highlight some of the design challenges and open issues that still need to be addressed to make BANs truly ubiquitous for a wide range of applications.     

Advances in Wearable Strain Sensors Based on Electrospun Fibers

Wearable strain sensors with the ability of detecting physiological activities play an important role in personalized healthcare. Electrospun fibers have become a popular building block for wearable strain sensors due to their excellent mechanical properties, breathability, and light weight. In this review, the structure and preparation process of electrospun fibers and the conductive layer are systematically introduced. The impact of materials and structures of electrospun fibers on the wearable strain sensors with a following discussion of sensing performance optimization strategies is outlined. Furthermore, the applications of electrospun fiber-based wearable strain sensors in biomonitoring, motion detection, and human-machine interaction are presented. Finally, the challenges and promising future directions for the community of wearable strain sensors based on electrospun fibers are pointed out.     

Personalized Healthcare System for Chronic Disease Care in Cloud Environment

The rapid increase in the number of patients with chronic diseases is an important public healthcare issue in many countries, which accelerates many studies on a healthcare system that can, whenever and wherever, extract and process patient data. A patient with a chronic disease conducts self‐management in an out‐of‐hospital environment, particularly in an at‐home environment, so it is important to provide integrated and personalized healthcare services for effective care. To help provide effective care for chronic disease patients, we propose a service flow and a new cloud‐based personalized healthcare system architecture supporting both at‐home and at‐hospital environments. The system considers the different characteristics of at‐hospital and at‐home environments, and it provides various chronic disease care services. A prototype implementation and a predicted cost model are provided to show the effectiveness of the system. The proposed personalized healthcare system can support cost‐effective disease care in an at‐hospital environment and personalized self‐management of chronic disease in an at‐home environment.