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

Karen Lopez-Linares Roman,Luc Martens,Günter Vermeeren,Wout Joseph,Arno Thielens

doi:10.1186/1687-1499-2014-21

Karen Lopez-Linares Roman, Luc Martens + Show 3 more

Open Access

https://doi.org/10.1186/1687-1499-2014-21

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Abstract

Abstract 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.

Highlights

A wireless body area network (WBAN) connects nodes that are situated on or in the body of a person
The objective of this paper is to investigate numerically the path loss (PL) of an in-to-out body radio frequency (RF) wireless link between an endoscopy capsule and a halfwavelength dipole outside the body using a 3D electromagnetic solver, applying the finite difference time domain (FDTD) method
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

Summary

Introduction

A wireless body area network (WBAN) connects nodes that are situated on or in the body of a person. Applications of WBANs include medicine and health care, sports, and multimedia. As it facilitates movement among users, it has brought about a revolutionary change in patient monitoring and healthcare facilities. Active implants placed within the human body lead to better and faster diagnosis, improving the quality of life of the patient. The development of an endoscopy capsule system enables the examination of areas of the small intestine that cannot be seen by other types of endoscopy. The benefits of the capsule endoscopy in terms of a better diagnosis are obvious. The patient’s comfort improves, as there are no wires or tubes involved in the procedure

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