In-body path loss models for implants in heterogeneous human tissues using implantable slot dipole conformal flexible antennas

A wireless body area network (WBAN) consists of a wireless network with devices placed close to, attached on, or implanted into the human body. Wireless communication within a human body experiences loss in the form of attenuation and absorption. A path loss model is necessary to account for these losses. In this article, path loss is studied in the heterogeneous anatomical model of a 6-year male child from the Virtual Family using an implantable slot dipole conformal flexible antenna and an in-body path loss model is proposed at 2.45 GHz with application to implants in a human body. The model is based on 3D electromagnetic simulations and is compared to models in a homogeneous muscle tissue medium

Characterization of path loss and absorption for a wireless radio frequency link between an in-body endoscopy capsule and a receiver outside the body

Physical-layer characterization is important for design of in-to-out body communication for wireless body area networks (WBANs). This paper numerically investigates the path loss and absorption of an in-to-out body radio frequency (RF) wireless link between an endoscopy capsule and a receiver outside the body using a 3D electromagnetic solver. A spiral antenna in the endoscopy capsule is tuned to operate in the Medical Implant Communication Service (MICS) band at 402 MHz, accounting for the properties of the human body. The influence of misalignment, rotation of the capsule, and three different human models are investigated. Semi-empirical path loss models for various homogeneous tissues and 3D realistic human body models are provided for manufacturers to evaluate the performance of in-body to out-body WBAN systems. The specific absorption rate (SAR) in homogeneous and heterogeneous body models is characterized and compliance is investigated

A review of recent innovations in remote health monitoring

The development of remote health monitoring systems has focused on enhancing healthcare services’ efficiency and quality, particularly in chronic disease management and elderly care. These systems employ a range of sensors and wearable devices to track patients’ health status and offer real-time feedback to healthcare providers. This facilitates prompt interventions and reduces hospitalization rates. The aim of this study is to explore the latest developments in the realm of remote health monitoring systems. In this paper, we explore a wide range of domains, spanning antenna designs, small implantable antennas, on-body wearable solutions, and adaptable detection and imaging systems. Our research also delves into the methodological approaches used in monitoring systems, including the analysis of channel characteristics, advancements in wireless capsule endoscopy, and insightful investigations into sensing and imaging techniques. These advancements hold the potential to improve the accuracy and efficiency of monitoring, ultimately contributing to enhanced health outcomes for patients.Publisher's VersionQ2WOS:001130630400001PMID:3813832

Ultrawideband Technology for Medical In-Body Sensor Networks: An Overview of the Human Body as a Propagation Medium, Phantoms, and Approaches for Propagation Analysis

[EN] An in-body sensor network is that in which at least one of the sensors is located inside the human body. Such wireless in-body sensors are used mainly in medical applications, collecting and monitoring important parameters for health and disease treatment. IEEE Standard 802.15.6-2012 for wireless body area networks (WBANs) considers in-body communications in the Medical Implant Communications Service (MICS) band. Nevertheless, high-data-rate communications are not feasible at the MICS band because of its narrow occupied bandwidth. In this framework, ultrawideband (UWB) systems have emerged as a potential solution for in-body highdata-rate communications because of their miniaturization capabilities and low power consumption.This work was supported by the Programa de Ayudas de Investigación y Desarrollo (PAID-01-16) at the Universitat Politècnica de València, Spain; by the Ministerio de Economía y Competitividad, Spain (TEC2014-60258-C2-1-R); and by the European FEDER funds. It was also funded by the European Union’s H2020:MSCA:ITN program for the Wireless In-Body Environ-ment Communication–WiBEC project under grant 675353.Garcia-Pardo, C.; Andreu-Estellés, C.; Fornés Leal, A.; Castelló-Palacios, S.; Pérez-Simbor, S.; Barbi, M.; Vallés Lluch, A.... (2018). Ultrawideband Technology for Medical In-Body Sensor Networks: An Overview of the Human Body as a Propagation Medium, Phantoms, and Approaches for Propagation Analysis. IEEE Antennas and Propagation Magazine. 60(3):19-33. https://doi.org/10.1109/MAP.2018.2818458S193360

UWB radio channel and diversity characterization for wireless implanted devices

Las redes de área corporal permiten la interconexión de nodos independientes situados dentro o fuera de la superficie corporal o, incluso, alejados de dicha superficie. En cuanto a las comunicaciones intracorporales, el establecimiento de un enlace robusto con una cápsula endoscópica o con un marcapasos, son ejemplos de los avances tecnológicos conseguidos en las últimas décadas. A pesar de estos desarrollos en asistencia sanitaria, los estándares actuales para este tipo de comunicaciones no permiten conexiones inalámbricas de alta velocidad de transmisión, las cuales son comunes en los servicios actuales de telecomunicaciones. Los sistemas UWB han surgido como potencial candidato para las futuras redes de comunicaciones inalámbricas intracorporales. No obstante, el principal obstáculo de la tecnología UWB para aplicaciones intracorporales es la alta atenuación que sufren las señales transmitidas al atravesar los distintos tejidos corporales, que aumenta drásticamente con el aumento de la frecuencia. Por tanto, es importante una caracterización precisa del canal UWB intracorporal a la hora de validar dicha banda como la adecuada para este propósito.Esta tesis se centra en el análisis de la tecnología UWB para posibilitar comunicaciones intracorporales inalámbricas desde un punto de vista experimental. Para conseguir este objetivo, se ha empleado un novedoso sistema de medidas experimental basado en fantomas en diversos escenarios de propagación intracorporal. De esta forma, se pueden comprobar las pérdidas de propagación en el medio así como la diversidad del canal de una forma fiable. Con el fin de validar los valores obtenidos en el laboratorio, se han comparado y analizado con los obtenidos en un experimento in vivo. Por otro lado, se han diseñado y fabricado nuevas antenas UWB candidatas para comunicaciones intracorporales, empleando técnicas existentes y nuevas de miniaturización y optimización. Finalmente, se han usado técnicas basadas en diversidad para mejorar el rendimiento del canal de propagación en dos escenarios intracorporales diferentes.Wireless Body Area Networks allow the interconnection between independent nodes located either inside or over the body skin or further. Regarding in-body communications, establishing a proper link with a capsule endoscope or with a pacemaker are examples of technological advances achieved in the last decades. In spite of these healthcare developments, current standards for these kind of communications do not allow high data rate wireless connections, which are common in the current telecommunication services. UWB systems have emerged as a potential solution for future wireless in-body communications. Nevertheless, the main drawback of UWB for in-body applications is the high attenuation of human body tissues which increases dramatically with the increment of frequency. Hence, an accurate UWB in-body channel characterization is relevant in order validate UWB frequency band as the best candidate for future networks of implantable nodes. This thesis is devoted to test UWB technology for in-body communications from an experimental point of view. To achieve this goal, a novel spatial phantom-based measurement setup is used in several in-body propagation scenarios. Thus, the losses in the propagation medium and the channel diversity are checked in a reliable way. In order to check the values obtained in laboratory, they are compared and discussed with those obtained in an in vivo experiment. On the other hand, new UWB antenna candidates for inbody communications are designed and manufactured by using typical and new miniaturization and antenna optimization techniques for this purpose. Finally, diversity-based techniques are used to improve the performance of the propagation channel in two different in-body scenarios.Les xarxes d'àrea corporal permeten la interconnexió de nodes independents situats, o bé dins, o bé sobre la pell, o inclús allunyats del propi cos. Pel que fa a les comunicacions intracorporals, l'establiment d'un bon enllaç amb una càpsula endoscòpica o amb un marcapassos, són exemples dels avanços tecnològics aconseguits les darreres dècades. A pesar d'aquests desenvolupaments en assistència sanitària, els estàndards actuals per a aquests tipus de comunicacions no permeten connexions sense fil d'alta velocitat de transmissió, que són habituals als serveis actuals de telecomunicacions. Els sistemes UWB han sorgit com una solució potencial per a les futures comunicacions sense fill intracorporals. No obstant, el principal obstacle de la tecnologia UWB per a les aplicacions intracorporals és l'alta atenuació dels teixits del cos humà, que augmenta dràsticament amb l'increment de freqüència. Per tant, és important una caracterització acurada del canal UWB intracorporal a l'hora de validar la banda de freqüència UWB com a la millor candidata per a les futures xarxes de nodes implantats.Aquesta tesi se centra en l'anàlisi de la tecnologia UWB per a comunicacions intracorporals des d'un punt de vista experimental. Per a aconseguir aquest objectiu s'ha emprat un sistema novedós de mesures experimentals, basat en fantomes, en diversos escenaris de propagació intracorporal. D'aquesta manera es poden comprovar les pèrdues de propagació en el medi i la diversitat del canal d'una forma fiable. Per tal d'avaluar els valors obtinguts al laboratori, s'han comparat i analitzat amb aquells obtinguts en un experiment in vivo. Per altra banda, s'han dissenyat i fabricat noves antenes UWB candidates per a comunicacions intracorporals emprant tècniques típiques i noves de miniaturització i optimització d'antenes per a aquest propòsit. Finalment s'han usat tècniques basades en diversitat per a millorar el rendiment del canal de propagació en dos escenaris intracorporals diferents.Andreu Estellés, C. (2018). UWB radio channel and diversity characterization for wireless implanted devices [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/111836TESI

Dielectric Characterization of In Vivo Abdominal and Thoracic Tissues in the 0.5 26.5 GHz Frequency Band for Wireless Body Area Networks

(c) 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.[EN] The dielectric properties of biological tissues are of utmost importance in the development of wireless body area networks (WBANs), especially for implanted devices. The early design stages of medical devices like capsule endoscopy, pacemakers, or physiological sensors rely on precise knowledge of the dielectric properties of the tissues present in their surrounding medium. Many of these applications make use of electromagnetic phantoms, which are software or physical models that imitate the shape and the electromagnetic properties of the tissues. They are used for designing devices in software simulations and for testing them in laboratory trials, aiding in both the development of WBAN antennas or in communication link evaluations. The existing reports about dielectric in vivo properties are limited and have drawbacks like: low variety of characterized tissues, lacking some relevant ones, and limitations and inhomogeneity in the measured frequency range. This paper aims at filling that gap by providing a new database of dielectric properties of biological tissues measured in vivo . In particular, it is focused on the tissues of the thoracic and the abdominal regions, measured at the same wide frequency band, on the same animal specimen, and under the same conditions. The properties have been obtained by measuring porcine tissues in the 0.5¿26.5 GHz band with the open-ended coaxial technique. In this paper, we focus on those tissues that have been scarcely characterized so far in the literature, like heart, esophagus, stomach, and pancreas. The Cole¿Cole fitting parameters of the measured tissues and their uncertainties are provided.This work was supported in part by UPV-IIS LaFe Program (STuDER, 2016, and EMOTE, 2018), in part by the Programa de Ayudas de Investigacion y Desarrollo (PAID-01-16) from the Universitat Politecnica de Valencia, in part by the European Union's H2020: MSCA: ITN Programs for the "Wireless In-Body Environment Communication-WiBEC'' Project, under Grant 675353, and in part by the "mmWave Communications in the Built Environments-WaveComBE'' Project, under Grant 766231.Fornés Leal, A.; Cardona Marcet, N.; Frasson, M.; Castelló-Palacios, S.; Nevárez, A.; Pons Beltrán, V.; Garcia-Pardo, C. (2019). Dielectric Characterization of In Vivo Abdominal and Thoracic Tissues in the 0.5 26.5 GHz Frequency Band for Wireless Body Area Networks. IEEE Access. 7:31854-31864. https://doi.org/10.1109/ACCESS.2019.2903481S3185431864

UWB Path Loss Models for Ingestible Devices

[EN] Currently, some medical devices such as the Wireless Capsule Endoscopy (WCE) are used for data transmission from inside to outside the body. Nevertheless, for certain applications such as WCE, the data rates offered by current medical frequency bands can result insufficient. Ultra Wideband (UWB) frequency band has become an interesting solution for this. However, to date, there is not a formal channel path loss model for the UWB frequency band in the gastrointestinal (GI) scenario due to the huge differences between the proposed studies. There are three main methodologies to characterize the propagation channel, software simulations and experimental measurements either in phantom or in in vivo animals. Previous works do not compare all the methodologies or present some disagreements with the literature. In this paper, a dedicated study of the path loss using the three methodologies aforementioned (simulations, phantoms and in vivo measurements) and a comparison with previous researches in the literature is performed. Moreover, numerical values for a path loss model which agrees with the three methodologies and the literature are proposed. This paper aims at being the starting point for a formal path loss model in the UWB frequency band for WBANs in the GI scenarioThis work was supported in part by the European Union's H2020-MSCA-ITN Program for the "Wireless In-body Environment Communication" Project under Grant 675353, in part by the Programa de Ayudas de Investigacion y Desarrollo (PAID-01-16) from Universitat Politecnica de Valencia, and in part by the Ministerio de Economia y Competitividad, Spain under Grant TEC2014-60258-C2-1-R through the European FEDER Funds.Pérez-Simbor, S.; Andreu-Estellés, C.; Garcia-Pardo, C.; Frasson, M.; Cardona Marcet, N. (2019). UWB Path Loss Models for Ingestible Devices. IEEE Transactions on Antennas and Propagation. 67(8):5025-5034. https://doi.org/10.1109/TAP.2019.2891717S5025503467