Intra-Body Communications for Nervous System Applications: Current Technologies and Future Directions

The Internet of Medical Things (IoMT) paradigm will enable next generation healthcare by enhancing human abilities, supporting continuous body monitoring and restoring lost physiological functions due to serious impairments. This paper presents intra-body communication solutions that interconnect implantable devices for application to the nervous system, challenging the specific features of the complex intra-body scenario. The presented approaches include both speculative and implementative methods, ranging from neural signal transmission to testbeds, to be applied to specific neural diseases therapies. Also future directions in this research area are considered to overcome the existing technical challenges mainly associated with miniaturization, power supply, and multi-scale communications.Comment: https://www.sciencedirect.com/science/article/pii/S138912862300163

A Review on Opportunities to Assess Hydration in Wireless Body Area Networks

The study of human body hydration is increasingly leading to new practical applications, including online assessment techniques for whole body water level and novel techniques for real time assessment methods as well as characterization for fitness and exercise performance. In this review, we will discuss the different techniques for assessing hydration from electrical properties of tissues and their components and the biological relations between tissues. This will be done mainly in the context of engineering while highlighting some applications in medicine, mobile health and sports

Estudio de la variabilidad de las medidas de comunicaciones intracorporales ante diferentes sujetos con diferentes características

El significativo avance de las Tecnologías de la Información y la Comunicación (TIC) en los últimos tiempos permite su aplicación en el sector de la salud de numerosas maneras, aportando beneficios de calidad, seguridad y un importante ahorro económico. En este ámbito toman gran relevancia los Sistemas de Salud Personales (PHS) que suponen una innovación ideada para ofrecer una asistencia sanitaria ininterrumpida, individualizada y de calidad controlada. En este marco se presentan las redes de sensores corporales (BSN) como una solución para el seguimiento de personas con problemas de salud, ya que las redes de sensores corporales surgen como respuesta a la necesidad de garantizar la individualización en la asistencia sanitaria y la prevención, así como mejorar la calidad de vida del paciente. Las redes inalámbricas de sensores proporcionan sistemas personalizados de atención médica que permiten la monitorización remota del paciente [1] en cualquier momento y lugar. Que el paciente sea supervisado las 24 horas del día influye en la necesidad de considerar que estas redes de sensores sean inalámbricas para una mayor comodidad, así como el tamaño de los sensores, u otros aspectos como el consumo de baterías, la inmunidad frente a interferencias, el alcance y la tasa de transmisión de datos. Zigbee o Bluetooth Low Energy (BLE) son estándares de comunicaciones empleados en redes inalámbricas de área personal que actualmente son implementadas pero con una serie de limitaciones [2] como: el número de dispositivos que se pueden usar, la velocidad [3] de transmisión de datos o interferencias con dispositivos que trabajen en la misma frecuencia. Debido a estas limitaciones surgieron las Intrabody Communication (IBC). Las Intrabody Communication emplean el cuerpo humano como medio de transmisión de las señales eléctricas para la interconexión de sensores inalámbricos en los sistemas de monitorización biomédicos. En este caso, la señal queda confinada en la superficie de la piel sin radiar al exterior, por lo que disminuye tanto las interferencias con dispositivos cercanos, como el consumo. Por ello, este tipo de comunicación es adecuada para aplicaciones biomédicas. No obstante, al ser las señales transmitidas a través de la superficie corpotal, se ven condicionadas por las propiedades de los tejidos vivos creando incertidumbre en las medidas. En este trabajo se ha realizado un análisis de la influencia de las características antropométricas en las comunicaciones intracorporales. Para ello, y como consecuencia de la falta de estandarización en las medidas en IBC y la incertidumbre que presenta el cuerpo humano, se ha empleado un modelo circuital (phantom) con el propósito de validar los distintos montajes experimentales empleados antes de las pruebas finales sobre voluntarios. Dicho phantom modela el comportamiento en frecuencia de los distintos tejidos que componen el brazo humano. El análisis fue realizado desde dos puntos de vista. En primer lugar se analizó la impedancia de entrada, con el propósito de estimar la corriente inyectada y mantenerla dentro de los márgenes de seguridad. En segundo lugar se analizó la atenuación de la señal en diversas frecuencias y diferentes distancias con el propósito de proporcionar información sobre las características del canal de comunicaciones corporal. A continuación, se procedió a realizar las medidas experimentales con dos sujetos de diferentes características. Las diferencias encontradas pusieron de manifiesto la importancia de las características antropométricas en las comunicaciones corporales. Como la señal se atenuaba rápidamente a medida que aumentaba la distancia, se encontraron serios problemas a la hora de medir en distancias superiores a 12 cm. El ruido en los niveles de señal obtenidos también resultaba importante, lo que impedía la realización de medidas objetivas para distancias mayores. Para resolver el problema de la señal atenuada se diseñó una etapa amplificadora en recepción. Para ello se realizó un estudio de amplificadores y de posibles configuraciones de circuitos para conseguir amplificar la señal. Aun solventando este problema de la atenuación, la señal seguía estando interferida por el ruido. Se realizó un proceso iterativo para eliminar el ruido de la señal implementando un circuito electrónico de captura de señal con tres electrodos. Este tercer terminal permitía obtener un punto de referencia para las medidas y de esta forma se conseguía eliminar el ruido. Se realizaron simulaciones en el osciloscopio para analizar los efectos que se producían en la señal recibida cuando se implementaba el tercer electrodo en las mediciones. Una vez comprobado los efectos, se volvieron a realizar medidas con diferentes personas para estudiar la influencia de las características de los distintos sujetos. Los resultados obtenidos para los dos sujetos con el setup mejorado fueron muy distintos, y estos resultados, a su vez, discrepaban de los resultados obtenidos para los dos sujetos de la primera experimentación. El setup mejorado ha permitido realizar medidas del canal de comunicaciones corporal a mayores distancias que el setup inicial. Los circuitos electrónicos de la etapa de captura de señal para la amplificación y eliminación de ruido con el tercer electrodo podrían ser empleados para optimizar las prestaciones de un transceptor en comunicaciones intracorporales.The significant advancement of information and communications technology (ICT ) in recent times allows implementation in the health sector in many ways providing quality benefits , safety and significant financial savings. In this area Personal Health Systems ( PHS ) take great relevance which represent an innovation designed to deliver an uninterrupted , individualized and quality controlled health care. In this framework the body sensor networks (BSN ) are shown as a solution for tracking people with health problems because the body sensor networks arise in response to the necesity to ensure individualization in health care and prevention as well as improve the quality of life of patients. Wireless sensor networks provide personalized health care systems that allow remote monitoring of the patient at any time and place. The patient is monitored 24 hours a day influences the need to consider these sensor networks are wireless for comfort as well as the size of the sensors, or other aspects such as battery consumption, immunity against interference the extent and rate of data transmission. Standards such as Zigbee or Bluetooth Low Energy ( BLE ) are wireless personal area networks that they are currently implemented but with a number of limitations such as the number of devices that it can be used , the speed of data transmission or interference with devices that work in the same frequency. Because of these limitations intrabody Communication ( IBC ) emerged. The Intrabody Communication employ the human body as a transmission medium of electrical signals to interconnect wireless sensor in biomedical monitoring systems. In this case, the signal is confined to the skin surface without radiating to the outside, thereby decreasing both interference with nearby devices such as consumption. Therefore, this type of communication is suitable for biomedical applications. However, when signals are transmitted through the corpotal surface, they are conditioned by the properties of living tissue by creating uncertainty in the measurements. The analysis was conducted from two points of view. Firstly, the input impedance was analyzed in order to estimate the injected current and keep within safety margins analyzed. Secondly, the signal attenuation at different frequencies and different distances was analyzed in order to provide information on the channel characteristics body communications. Then it proceeded to perform experimental measurements with two subjects with different characteristics. The differences highlighted the importance of anthropometric characteristics in body communications. As the signal is attenuated rapidly with increasing distance, serious problems when measured at distances exceeding 12 cm were found. The noise in the signal levels obtained also was important, which prevented the realization of objective measures for greater distances. To solve the problem of the attenuated signal design a amplifier stage in reception. For this, study amplifiers and possible circuit configurations was performed for amplifying the signal. Even solving this problem of attenuation, the signal was still interfered by noise. An iterative process was performed to remove noise signal implementing a phantom with three terminals. This third terminal allowed to obtain a reference point for measurements and thus eliminate noise was achieved. Simulations were performed on the oscilloscope to analyze the effects that occurred in the received signal when the third electrode was implemented in measurements. Once verified the effects, measurements with different people returned to perform to study the influence of the characteristics of the different subjects. The results obtained for the two subjects with improved setup were very different, and these results, in turn, results obtained differed for the two subjects of the first experimentation. The setup has allowed improved measures body channel communications over greater distances than the initial setup. The electronic circuitry of the capture step signal for amplification and elimination of noise with the third electrode could be used to optimize the performance of a transceiver in intracorporeal communications.Universidad de Sevilla. Grado en Ingeniería de las Tecnologías de Telecomunicació

Wireless body sensor networks for health-monitoring applications

This is an author-created, un-copyedited version of an article accepted for publication in Physiological Measurement. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0967-3334/29/11/R01

Application-Specific Things Architectures for IoT-Based Smart Healthcare Solutions

Human body is a complex system organized at different levels such as cells, tissues and organs, which contributes to 11 important organ systems. The functional efficiency of this complex system is evaluated as health. Traditional healthcare is unable to accommodate everyone's need due to the ever-increasing population and medical costs. With advancements in technology and medical research, traditional healthcare applications are shaping into smart healthcare solutions. Smart healthcare helps in continuously monitoring our body parameters, which helps in keeping people health-aware. It provides the ability for remote assistance, which helps in utilizing the available resources to maximum potential. The backbone of smart healthcare solutions is Internet of Things (IoT) which increases the computing capacity of the real-world components by using cloud-based solutions. The basic elements of these IoT based smart healthcare solutions are called "things." Things are simple sensors or actuators, which have the capacity to wirelessly connect with each other and to the internet. The research for this dissertation aims in developing architectures for these things, focusing on IoT-based smart healthcare solutions. The core for this dissertation is to contribute to the research in smart healthcare by identifying applications which can be monitored remotely. For this, application-specific thing architectures were proposed based on monitoring a specific body parameter; monitoring physical health for family and friends; and optimizing the power budget of IoT body sensor network using human body communications. The experimental results show promising scope towards improving the quality of life, through needle-less and cost-effective smart healthcare solutions

Conformable transistors for bioelectronics

The diversity of network disruptions that occur in patients with neuropsychiatric disorders creates a strong demand for personalized medicine. Such approaches often take the form of implantable bioelectronic devices that are capable of monitoring pathophysiological activity for identifying biomarkers to allow for local and responsive delivery of intervention. They are also required to transmit this data outside of the body for evaluation of the treatment’s efficacy. However, the ability to perform these demanding electronic functions in the complex physiological environment with minimum disruption to the biological tissue remains a big challenge. An optimal fully implantable bioelectronic device would require each component from the front-end to the data transmission to be conformable and biocompatible. For this reason, organic material-based conformable electronics are ideal candidates for components of bioelectronic circuits due to their inherent flexibility, and soft nature. In this work, first an organic mixed-conducting particulate composite material (MCP) able to form functional electronic components and non-invasively acquire high–spatiotemporal resolution electrophysiological signals by directly interfacing human skin is presented. Secondly, we introduce organic electrochemical internal ion-gated transistors (IGTs) as a high-density, high-amplification sensing component as well as a low leakage, high-speed processing unit. Finally, a novel wireless, battery-free strategy for electrophysiological signal acquisition, processing, and transmission that employs IGTs and an ionic communication circuit (IC) is introduced. We show that the wirelessly-powered IGTs are able to acquire and modulate neurophysiological data in-vivo and transmit them transdermally, eliminating the need for any hard Si-based electronics in the implant

A health-shirt using e-textile materials for the continuous monitoring of arterial blood pressure.

Chan, Chun Hung.Thesis (M.Phil.)--Chinese University of Hong Kong, 2008.Includes bibliographical references (leaves 77-84).Abstracts in Chinese and English.Acknowledgment: --- p.i摘要 --- p.iiAbstract --- p.ivList of Figure --- p.viList of Table --- p.viiiContent Page --- p.ixChapter Chapter 1 --- Introduction --- p.1Chapter 1.1 --- The Difficulties --- p.1Chapter 1.2 --- The Solution --- p.2Chapter 1.3 --- Goal of the Present Work --- p.2Chapter Chapter 2 --- Background and Methodology --- p.3Chapter 2.1 --- Hypertension Situation and Problems Around the World --- p.3Chapter 2.1.1 --- Blood Pressure Variability (BPV) --- p.4Chapter 2.2 --- Blood Pressure Measuring Methods --- p.5Chapter 2.2.1 --- Traditional Blood Pressure Meters --- p.6Chapter 2.2.2 --- Limitation of Commercial Blood Pressure Meters --- p.7Chapter 2.2.3 --- Pulse-Transit-Time (PTT) Based Blood Pressure Measuring Watch --- p.7Chapter 2.3 --- Wearable Body Sensors Network / System --- p.8Chapter 2.4 --- Current Status of e-Textile Garment --- p.9Chapter 2.4.1 --- Blood Pressure Measurement in e-Textile Garment --- p.13Chapter 2.5 --- Wearable Intelligent Sensors and System for e-Health (WISSH) --- p.15Chapter 2.5.1 --- "Monitoring, Connection and Display" --- p.15Chapter 2.5.2 --- Treatment --- p.16Chapter 2.5.3 --- Alarming --- p.17Chapter Chapter 3 --- "A h-Shirt to Non-invasive, Continuous Monitoring of Arterial Blood Pressure" --- p.18Chapter 3.1 --- Design and Inner Structure of h-Shirt --- p.18Chapter 3.1.1 --- Choose of e-Textile Material --- p.21Chapter 3.1.2 --- Design of ECG Circuit --- p.23Chapter 3.1.3 --- Design of PPG Circuit --- p.26Chapter 3.2 --- Blood Pressure Estimation Using Pulse-Transit-Time Algorithm --- p.28Chapter 3.2.1 --- Principal --- p.28Chapter 3.2.2 --- Equations --- p.29Chapter 3.2.3 --- Calibration --- p.29Chapter 3.3 --- Performance Tests on h-Shirt --- p.30Chapter 3.3.1 --- Test I: BP Measurement Accuracy --- p.30Chapter 3.3.2 --- Test I: Procedure and Protocol --- p.30Chapter 3.3.3 --- Test I-Results --- p.31Chapter 3.3.4 --- Test II: Continuality BP Estimation Performance --- p.31Chapter 3.3.5 --- Test II - Experiment Procedure and Protocol --- p.32Chapter 3.3.6 --- Test II - Experiment Result --- p.33Chapter 3.3.7 --- Test II 一 Discussion --- p.43Chapter 3.4 --- Follow-up Tests on ECG Circuit --- p.47Chapter 3.4.1 --- Problems --- p.47Chapter 3.4.2 --- Assumptions --- p.48Chapter 3.4.3 --- Experiment Protocol and Setup --- p.48Chapter 3.4.4 --- Experiment Results --- p.53Chapter 3.4.5 --- Discussion --- p.56Chapter Chapter 4: --- Hybrid Body Sensor Network in h-Shirt --- p.59Chapter 4.1 --- A Hybrid Body Sensor Network --- p.59Chapter 4.2 --- Biological Channel Used in h-Shirt --- p.60Chapter 4.3 --- Tests of Bio-channel Performance --- p.62Chapter 4.3.1 --- Experiment Protocol --- p.62Chapter 4.3.2 --- Results --- p.62Chapter 4.4 --- Discussion and Conclusion --- p.63Chapter Chapter 5: --- Conclusion and Suggestions for Future Works --- p.66Chapter 5.1 --- Conclusion --- p.66Chapter 5.1.1 --- Structure of h-Shirt --- p.66Chapter 5.1.2 --- Blood Pressure Estimating Ability of h-Shirt --- p.67Chapter 5.1.3 --- Tests and Amendments on h-Shirt ECG Circuit --- p.67Chapter 5.1.4 --- Hybrid Body Sensor Network in h-Shirt --- p.67Chapter 5.2 --- Suggestions for Future Work --- p.68Chapter 5.2.1 --- Further Development of Bio-channel Biological Model --- p.68Chapter 5.2.2 --- Positioning and Motion Sensing with h-Shirt --- p.69Chapter 5.2.3 --- Implementation of Updated Advance Technology into h-Shirt --- p.69Appendix: Non-invasive BP Measuring Device - Finometer --- p.71Reference: --- p.7

Communication and energy delivery architectures for personal medical devices

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 219-232).Advances in sensor technologies and integrated electronics are revolutionizing how humans access and receive healthcare. However, many envisioned wearable or implantable systems are not deployable in practice due to high energy consumption and anatomically-limited size constraints, necessitating large form-factors for external devices, or eventual surgical re-implantation procedures for in-vivo applications. Since communication and energy-management sub-systems often dominate the power budgets of personal biomedical devices, this thesis explores alternative usecases, system architectures, and circuit solutions to reduce their energy burden. For wearable applications, a system-on-chip is designed that both communicates and delivers power over an eTextiles network. The transmitter and receiver front-ends are at least an order of magnitude more efficient than conventional body-area networks. For implantable applications, two separate systems are proposed that avoid reimplantation requirements. The first system extracts energy from the endocochlear potential, an electrochemical gradient found naturally within the inner-ear of mammals, in order to power a wireless sensor. Since extractable energy levels are limited, novel sensing, communication, and energy management solutions are proposed that leverage duty-cycling to achieve enabling power consumptions that are at least an order of magnitude lower than previous work. Clinical measurements show the first system demonstrated to sustain itself with a mammalian-generated electrochemical potential operating as the only source of energy into the system. The second system leverages the essentially unlimited number of re-charge cycles offered by ultracapacitors. To ease patient usability, a rapid wireless capacitor charging architecture is proposed that employs a multi-tapped secondary inductive coil to provide charging times that are significantly faster than conventional approaches.by Patrick Philip Mercier.Ph.D