Multi-path 2-Port Channel Characterization for Galvanic Coupled Intra-body Communication

Sensors implanted inside a body compose so called intra body networks (IBNs), which promise high degree of mobility, remote diagnostic accuracy, and the potential of directly activating the action of drug delivery actuators. To enable communication among these implanted sensors, we use the concept of galvanic coupling, in which extremely low energy electrical signals are coupled into the human body tissues by leveraging the conductive properties of the tissues. Several challenges emerge in this new communication paradigm, such as how to appropriately model the signal propagation through various tissue paths such as from muscle to skin across different tissue boundaries and quantify the achievable data rates. The main contributions in this paper are: (i) we build a 2-port tissue equivalent circuit model to characterize the body channel and to identify the range of suitable operating frequencies and (ii) we theoretically estimate the channel capacity for various sensor locations that incorporates factors like the tissue propagation path, operating frequency and noise level.