Characterising THz propagation and intrabody thermal absorption in iWNSNs

Nanosized devices operating inside the human body will eventually facilitate transformative health monitoring and diagnosis systems. The interconnection of these implantable nanosensors forms an in vivo wireless nanosensor network (iWNSN), which allows autonomous data transmission and enables sensing, coordination, and control among its entities. In specific, with the development of miniature plasmonic signal sources, antennas and detectors, wireless communications among nanodevices points towards the terahertz band (0.1-10 THz) as a suitable platform and feasible wireless range to initiate intrabody communication. In this study, a rigorous channel model for intrabody communication in iWNSNs is developed. The total path loss is computed by taking into account the contribution of the spreading of the propagating wave, molecular absorption from human tissues, as well as scattering from both small and large body particles. The presented model is further complemented by investigating the photo-thermal interactions which arise from absorption at the THz frequency band. The aforementioned study which analyzes the propagation of electromagnetic signals inside the human body is fundamental to assess the feasibility of the THz frequency band, determine the requirements and controlling parameters of a THz intrabody system as well as highlight the health issues correlated with operating at such frequencies.