Past Results, Present Trends, and Future Challenges in Intrabody Communication

Abstract

Intrabody communication (IBC) is a wireless communication technology using the human body to develop body area networks (BANs) for remote and ubiquitous monitoring. IBC uses living tissues as a transmission medium, achieving power-saving and miniaturized transceivers, making communications more robust against external interference and attacks on the privacy of transmitted data. Due to these advantages, IBC has been included as a third physical layer in the IEEE 802.15.6 standard for wireless body area networks (WBANs) designated as Human Body Communication (HBC). Further research is needed to compare both methods depending on the characteristics of IBC application. Challenges remain for an optimal deployment of IBC technology, such as the effect of long-term use in the human body, communication optimization through more realistic models, the influence of both anthropometric characteristics and the subject's movement on the transmission performance, standardization of communications, and development of small-size and energy-efficient prototypes with increased data rate. The purpose of this work is to provide an indepth overview of recent advances and future challenges in human body/intrabody communication for wireless communications and mobile computing.

Physical Multi-Layer Phantoms for Intra-Body Communications

“…For instance, samples with low oil solution concentration can be utilized for mimicking tissue with high dielectric permittivity, while samples with high oil solution concentration can be used to mimic tissues with low conductivity like cortical bone, as shown in Figures As shown in Figures 6 and 7, the electrical properties of different tissues can be matched with samples of certain formulations and concentrations, depending on the electrical property of interest (whether conductivity or permittivity is more of concern), and the range of frequency in which the IBC application will operate within. It is important to note that most IBC applications utilize less than 1 MHz of bandwidth [22], due to the nature of medical applications, that typically require low bit rates. A summary of such results; best matching samples (samples that shows less than 10 % matching error) with respect to different tissues, regarding conductivity and permittivity, for different frequency ranges (Fmin is the minimum frequency and Fmax is the maximum frequency in MHz defining the band over which the matching error is below 10% ) within the IBC application band, is provided in Table 3.…”

“…Several trials were reported in literature for the use of phantoms for IBC applications as a stable and easy to control, yet accurate experimental setup [22], [23]. Liquid phantoms were usually adopted in these trials, being the easiest to prepare.…”

A Periodic Transmission Line Model for Body Channel Communication

“…The pioneering work of Zimmerman on BCC was motivated by the dream and the imagination of a digital interconnected world where the center of communication is the human being [1], [2]. Driven by this idea, BCC can be established relying on two main coupling mechanisms [3]. The signal can be coupled in the body by direct current injection (galvanic coupling -GC) from a transmitter (TX) electrode to a receiver (RX).…”

“…The signal can be coupled in the body by direct current injection (galvanic coupling -GC) from a transmitter (TX) electrode to a receiver (RX). Alternatively, the near-field coupling of a quasi-electrostatic field between TX and RX electrodes can be used for (capacitive coupling -CC) [3]- [9]. However, the possibility of conveying information in the sub-cutaneous fat at frequencies around 2.45 GHz is currently under investigation [10]- [12].…”

Biometric Identity Based on Intra-Body Communication Channel Characteristics and Machine Learning

“…Intra-body communications can be categorized into two main types; capacitive coupling (near-field coupling method) and galvanic coupling [13][14][15][16][17][18]. In capacitive coupling, only the signal electrodes of the transmitter and the receiver are attached to the body while the ground (GND) electrodes are left floating in the air.…”