Cascaded Network Body Channel Model for Intrabody Communication

Abstract

Intrabody communication has been of great research interest in recent years. This paper proposes a novel, compact but accurate body transmission channel model based on RC distribution networks and transmission line theory. The comparison between simulation and measurement results indicates that the proposed approach accurately models the body channel characteristics. In addition, the impedance-matching networks at the transmitter output and the receiver input further maximize the power transferred to the receiver, relax the receiver complexity, and increase the transmission performance. Based on the simulation results, the power gain can be increased by up to 16 dB after matching. A binary phase-shift keying modulation scheme is also used to evaluate the bit-error-rate improvement.

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

“…In this respect, the main proposals of channel models in IBC have been directed to the definition of both lumped [24,30,33,36,38,130,131] and distributed parameters circuit diagrams [18,35,37,40,132]. These models easily and intuitively incorporate some of the electrical characteristics of the different tissues, such as tissue resistivity and capacitive properties, as well as their dependence on frequency, thus helping obtain simple analytical expressions for both attenuation and dispersion through the human body.…”

“…The simplicity of the electric circuit body models in order to obtain useful analytic expressions for body attenuation justifies their use to guide the design of IBC transceivers and systems. Compared with numerical models, which usually present high computational cost, the electric circuit body models offer a compromise between [7] formed by eight capacitances to emulate the capacitive couplings between the body and the external ground, models have evolved towards complex RC networks emulating different tissue layers at both longitudinal and transversal directions [38][39][40], thus taking into account the frequency-dependent dielectric properties of tissues [34,46], the cross-impedances between TX and RX electrodes [33], the output and input resistance of the TX and RX device [36], and so forth. Electromagnetic models, both analytic and computational approaches, have attracted more and more the attention of IBC researchers giving rise to a variety of models ranging from simple geometries such as plane, cylinder, and parallelepiped, which emulate parts of the body such as limbs and trunk [9,41,46], to models based on the anatomy of the arm and the whole human body [42,50].…”

“…In Ohishi et al [148], capacitive electrodes are enhanced by inductance coils so that the resonance frequency is equal to the IBC frequency when the electrodes are close to human body surface. Impedance-matching networks at the transmitter output and the receiver input can also increase the transmission performance in capacitive coupling [12,40] (see Figure 11). …”

“…Copper has been used as the electrode material in many studies because of its good conductivity [141]: 25-mm × 25-mm [153], 3-cm × 3-cm [132], 2-cm × 2-cm [20,40,152,154,155], 6-cm × 8-cm [156], or circular with a radius of 10-mm [36]. Stainless-steel electrodes of 5-mm × 15-mm was employed in [157].…”

Investigation and Modeling of Multi-Node Body Channel Wireless Power Transfer

“…In [10], the skin propagation model was proposed based on a distributed-parameter circuit. In [11], the body transmission channel model was proposed based on RC distribution networks and transmission line theory. In [12], the human head and neck model was proposed.…”