Transmission of RF Signals Between MICS Loop Antennas in Free Space and Implanted in the Human Head

This communication characterizes the transmission of radio frequency (RF) signals in Medical Implant Communications Service (MICS) band (402-405 MHz) between the loop antennas placed in free space and implanted into a human head (beneath the skull) for medical applications. The investigation is carried out using a commercial EM simulator XFDTD based on a finite-difference time-domain (FDTD) method with a numerical human head model, and verified by the measurements with a phantom. The study shows the effects of human head on the transmission of RF signals between the antennas inside and outside a human head. The information derived from this study is useful for the link budget of medical systems with the wireless connection between implanted devices in human heads and external central controllers.