Implanted antennas for biotelemetry: antennas, safety and communications issues

Summary form only given. In this paper, some of the recent progress in modeling antennas near human/animal tissues are presented. In particular, simulation results for the EM characteristics of implanted antennas in both a human head and a human body are discussed. Since this study is related to biomedical applications, implanted antennas are assumed to operate using a biomedical frequency band 402-405 MHz. The antenna characterization is carried out using both the simplified multilayered spherical model and the sophisticated anatomical model. Both the finite difference time domain and dyadic Green´s function approaches are applied and compared. These computational techniques are used to design tailored antennas with improved performance when implanted inside the body. The importance of designing antennas to match their surrounding environment is shown. Attention is given to designing antennas with miniaturized characteristics and proper functionality in the tissue environment. Input impedance, SAR and radiation patterns of various antennas are determined and compared. The roles of global optimization techniques such as genetic algorithm and particle swarm to achieve optimal designs are also highlighted.