  Increasing number of devices being used in and around the human body has
resulted in the exploration of the human body as a communication medium. In
this paper, we design a channel model for implantable devices communicating
outside the body using physically secure Electro-Quasistatic Human Body
Communication. A galvanic receiver shows 5dB lower path loss than capacitive
receiver when placed close to transmitter whereas a capacitive receiver has
around 15dB lower path loss for larger separation between the transmitter and
receiver. Finite Element Method (FEM) based simulations are used to analyze the
communication channel for different receiver topologies and experimental data
is used to validate the simulation results.
