Numerical evaluation of the radar cross section of human breathing models

In this paper, anatomical models of the human body are used to evaluate the radar cross section (RCS) of breathing subjects. The study is performed by using a self-developed finite difference time domain (FDTD) code implemented in the message passing interface environment (MPI). The realized models represent three different phases of the breathing activity taking into account the respiration physiology and the pulmonary mechanics. In particular, the end expiration phase (resting state), the end of a normal inspiration phase (tidal), and the end of a deep inspiration phase (deep) were considered. Computed results show RCS values of the resting state model in agreement with literature data, and appreciable variations of the RCS determined by the breathing activity. Simulations performed with homogeneous body models suggest that these differences depend both on the model anatomy and on the tissue dielectric properties