UC Irvine

The desire to have ultra compact, low power, wearable and implanted biosensors/actuators encourages researchers to develop new communication methods that can replace current Radio Frequency (RF) wireless communication links. RF links require power and area hungry analog circuitry that limits the usability of such systems. This thesis conducts a thorough study on a promising technique called intra-body communication which utilizes the human body as a transmission medium, where galvanic coupling and capacitive coupling represent the main approaches to implement the intra-body communication (IBC) system.

IBCs literature review is presented showing the main motivation behind this research and the prior trials in the field, as well as highlighting the obstacles facing this technique. A circuit model is adopted to derive a transfer function that can capture the human channel properties to determine the transmission gain. Moreover, finite element method (FEM) technique is utilized to determine the path loss of the human channel, typically the human arm model, and to examine the current density distribution in human tissues using both a full and a reduced order model. In addition, the effect of bone fracture internal fixation implant effect on the channel parameters is investigated. Finally, to validate the FEM and circuit model, a fabricated human arm phantom is introduced in detail by covering the fabrication process, dielectric properties and transmission results.