Wearable and Nearable Biosensors and Systems for Healthcare

Biosensors and systems in the form of wearables and “nearables” (i.e., everyday sensorized objects with transmitting capabilities such as smartphones) are rapidly evolving for use in healthcare. Unlike conventional approaches, these technologies can enable seamless or on-demand physiological monitoring, anytime and anywhere. Such monitoring can help transform healthcare from the current reactive, one-size-fits-all, hospital-centered approach into a future proactive, personalized, decentralized structure. Wearable and nearable biosensors and systems have been made possible through integrated innovations in sensor design, electronics, data transmission, power management, and signal processing. Although much progress has been made in this field, many open challenges for the scientific community remain, especially for those applications requiring high accuracy. This book contains the 12 papers that constituted a recent Special Issue of Sensors sharing the same title. The aim of the initiative was to provide a collection of state-of-the-art investigations on wearables and nearables, in order to stimulate technological advances and the use of the technology to benefit healthcare. The topics covered by the book offer both depth and breadth pertaining to wearable and nearable technology. They include new biosensors and data transmission techniques, studies on accelerometers, signal processing, and cardiovascular monitoring, clinical applications, and validation of commercial devices

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

Non-ionizing radiofrequency electromagnetic waves traversing the head can be used to detect cerebrovascular autoregulation responses

Monitoring changes in non-ionizing radiofrequency electromagnetic waves as they traverse the brain can detect the effects of stimuli employed in cerebrovascular autoregulation (CVA) tests on the brain, without contact and in real time. CVA is a physiological phenomenon of importance to health, used for diagnosis of a number of diseases of the brain with a vascular component. The technology described here is being developed for use in diagnosis of injuries and diseases of the brain in rural and economically underdeveloped parts of the world. A group of nine subjects participated in this pilot clinical evaluation of the technology. Substantial research remains to be done on correlating the measurements with physiology and anatomy

Recent Advances on Implantable Wireless Sensor Networks

Implantable electronic devices are undergoing a miniaturization age, becoming more efficient and yet more powerful as well. Biomedical sensors are used to monitor a multitude of physiological parameters, such as glucose levels, blood pressure and neural activity. A group of sensors working together in the human body is the main component of a body area network, which is a wireless sensor network applied to the human body. In this chapter, applications of wireless biomedical sensors are presented, along with state-of-the-art communication and powering mechanisms of these devices. Furthermore, recent integration methods that allow the sensors to become smaller and more suitable for implantation are summarized. For individual sensors to become a body area network (BAN), they must form a network and work together. Issues that must be addressed when developing these networks are detailed and, finally, mobility methods for implanted sensors are presented

A Heart Rate Finger Ring and Its Smartphone APP Through Customized NFC

Population aging has become one of the most critical problems in contemporary society. Families and organizations are striving to provide better healthcare to the elderly and handicapped for their better living conditions. Due to these situations, the demand for remote health monitoring continues to grow rapidly. With the development of new technologies, such as smaller sensors and microcontrollers, the increasing widespread use of smartphones, and new wireless communication methods, a wireless body area network system can be constructed to provide more sophisticated solutions to satisfy this demand. The objective of this thesis is to demonstrate that such a system is feasible. A ring-shaped hardware device is implemented to measure the user’s heart rate and transfers the data to an Android phone through a customized Near Field Communication (NFC) tag. The tag is composed of a transponder to write data and a customized antenna to transfer data based on the resonance effect. An application is also developed to operate the NFC module to communicate with the tag. Data is then received, stored, and utilized on the phone. The ring and Android phone serve as Body Sensor Unit (BSU) and Body Central Unit (BCU) respectively in the Wireless Body Area Network (WBAN) system. Then NFC technology links them together wirelessly. In order to implement the NFC Ring, a sensor is placed within the ring to convert the heart rate into an electric signal. This signal is filtered and amplified and sent to a microcontroller. Next, the microcontroller generates a count for computing the time interval between two pulses. Then the count value is written to the NFC tag through an NFC transponder. The antenna is specially designed to meet two core constraints: the size should be as small as possible to fit the ring, while still maintaining the ability to produce a large enough magnetic field. When an Android phone approaches the ring, the application on the phone will execute and read data in the tag by controlling the NFC reader. After being received, the data is stored in a SQLite database on the phone for further processing, such as rendering a history chart to show the trend. A prototype of this system has been developed to demonstrate the idea. This prototype can accurately read the heart rate per minute. Compared with a Radio-Frequency Identification ring, the NFC Ring has reduced system complexity and improved mobility. There are many possible improvements on both hardware and software. For instance, more research on NFC antenna design to enhance the stability of data transmission should be considered. The algorithm of heart rate measurement may be refined to generate more accurate data. More explanation of heart rate data and its trend await further exploration as well

Design of a Customized multipurpose nano-enabled implantable system for in-vivo theranostics

The first part of this paper reviews the current development and key issues on implantable multi-sensor devices for in vivo theranostics. Afterwards, the authors propose an innovative biomedical multisensory system for in vivo biomarker monitoring that could be suitable for customized theranostics applications. At this point, findings suggest that cross-cutting Key Enabling Technologies (KETs) could improve the overall performance of the system given that the convergence of technologies in nanotechnology, biotechnology, micro&nanoelectronics and advanced materials permit the development of new medical devices of small dimensions, using biocompatible materials, and embedding reliable and targeted biosensors, high speed data communication, and even energy autonomy. Therefore, this article deals with new research and market challenges of implantable sensor devices, from the point of view of the pervasive system, and time-to-market. The remote clinical monitoring approach introduced in this paper could be based on an array of biosensors to extract information from the patient. A key contribution of the authors is that the general architecture introduced in this paper would require minor modifications for the final customized bio-implantable medical device

Wearable Devices for Single-Cell Sensing and Transfection

Wearable healthcare devices are mainly used for biosensing and transdermal delivery. Recent advances in wearable biosensors allow for long-term and real-time monitoring of physiological conditions at a cellular resolution. Transdermal drug delivery systems have been further scaled down, enabling wide selections of cargo, from natural molecules (e.g., insulin and glucose) to bioengineered molecules (e.g., nanoparticles). Some emerging nanopatches show promise for precise single-cell gene transfection in vivo and have advantages over conventional tools in terms of delivery efficiency, safety, and controllability of delivered dose. In this review, we discuss recent technical advances in wearable micro/nano devices with unique capabilities or potential for single-cell biosensing and transfection in the skin or other organs, and suggest future directions for these fields. Highlights • Current wearable sensors have allowed for long-term, real-time detection of specific biomarkers directly from patients. • Miniaturized wearable biosensors with sensing elements interacting with skin or organs can capture target molecules from single cells, which results in significantly increased sensitivity, responding time, and precision. • Emerging wearable devices based on novel nanomaterials or nanofabrication show potential for single-cell detection in cancer cell screening, cardiomyocyte detection, and optogenetics. • Transdermal delivery devices have been scaled down to the micro- and/or nanoscale, and their applications have extended to wide selections of natural molecules and bioengineered molecules. • Emerging nanodevices show unique capabilities in precise single-cell gene transfection in vivo, with improved delivery efficiency, safety, and dose controllability

A Bluetooth Low-Energy Wireless Sensor Platform for Continuous Monitoring of a Bioreactor Environment during Cell Manufacturing

A wireless sensor platform based on Bluetooth Low-Energy (BLE) technology was designed and prototyped for continuous monitoring of physical conditions and chemical analytes, which could be applied to bioreactors during the cell manufacturing process. Controlling environmental conditions such as pH, oxygen, glucose, temperature, and pressure is vital to ensure the consistency of the manufactured cells and maintain the potency of the product. Current methods to control bioreactor conditions focus only on monitoring the cell culture environment during cell growth, but there is a lack of direct quantification of cell properties to provide an integrated feedback system that can also maintain cell quality. Furthermore, current methods are typically expensive and inflexible for new bioreactor designs. The ultimate goal of this project is to develop a low-cost wireless sensor platform that can incorporate different types of sensors for monitoring both growth conditions and cell quality in various types of bioreactors. This thesis represents the first phase of the project with the development of the sensor platform and prototyping a pH and temperature sensor module along with the platform. Bench tests demonstrated the efficacy of these sensors in continuous monitoring of pH and temperature over several days. With the sensor functionality proven, the next step is to examine the biocompatibility of the sensor, as well as expand the parameters to include oxygen, glucose, and pressure. New sensors, such as those based on the impedimetric technique, will also be developed to direct cell quality evaluation