Proper Derivation of Equivalent-Circuit Expressions of Intra-Body Communication Channels Using Quasi-Static Field

Physical channels of the intra-body communications, in which communications are performed by exciting electric field around the human body, have been treated as a capacitive circuit from the beginning of the development. Although the circuit-like understanding of the channels are helpful to design devices and systems, there is a problem that the results may be invalid if the circuit parameters are incorrectly estimated. In the present study, the values of the circuit parameters are properly derived by solving a boundary value problem of electric potentials of the conductors. Furthermore, approximate models which are appropriate for cases that some of the conductors are grounded are investigated.