An Investigation on Propagation Characteristics of In-body Radio Channels for Wireless Implants

In this paper, a realistic high resolution human body model was presented to investigate the propagation characteristics of in-body radio channels (I-BRCs) at human body communication (HBC) frequency band for implantable devices. Specifically, the TX electrodes were implanted into the brain, heart, stomach, lung, and intestine, respectively, and the RX electrode was attached on the surface of abdomen. The parameters such as channel gain and group delay were explored through numerical simulations with finite-difference time-domain (FDTD) method in the frequency range IMHz to lOOMHz. The results showed that as the frequency increased, the channel gain of all five I-BRCs decreased when the frequency was below 50MHz. The group delay was frequency-dependent. Furthermore, the group delay of all channels had the minimum value at about 52MHz. In addition, a 45kg pig was employed as an experimental subject to verify the validity of simulations for 1-BRCs. The results indicated that the simulations were in agreement with the measurements.