Abstract-Photothermal Modeling and Analysis of Intra-body Terahertz Nanoscale Communication

Hadeel Elayan, Pedram Johari,  Raed M. Shubair, Josep Miquel Jornet

http://ieeexplore.ieee.org/document/8052555/

Wireless communication among implanted nanobiosensors will enable transformative smart health monitoring and diagnosis systems. The state of the art of nano-electronics and nano-photonics points to the Terahertz (THz) band (0.1-10 THz) and the optical frequency bands (infrared, 30-400 THz, and visible, 400-750 THz) as the frequency range for communication among nano-biosensors. Recently, several propagation models have been developed to study and assess the feasibility of intrabody electromagnetic (EM) nanoscale communication. These works have been mainly focused on understanding the propagation of EM signals through biological media, but do not capture the resulting photothermal effects and their impact both on the communication as well as on the body itself. In this paper, a novel thermal noise model for intra-body communication based on the diffusive heat flow theory is developed. In particular, an analytical framework is presented to illustrate how molecules in the human body absorb energy from EM fields and subsequently release this energy as heat to their immediate surroundings. As a result, a change in temperature is witnessed from which the molecular absorption noise can be computed. Such analysis has a dual benefit from a health as well as a communication perspective. For the medical community, the presented methodology allows the quantization of the temperature increase resulting from THz frequency absorption. For communication purposes, the complete understanding of the intra-body medium opens the door towards developing modulations suited for the capabilities of nano-machines and tailored to the peculiarities of the THz band channel as well as the optical window.

Abstract-Terahertz Channel Model and Link Budget Analysis for Intrabody Nanoscale Communication

Hadeel Elayan,  Raed M. Shubair,  Josep M. Jornet, Pedram Johari,

http://ieeexplore.ieee.org/document/7955066/

Nanosized devices operating inside the human body open up new prospects in the healthcare domain. In vivo wireless nanosensor networks (iWNSNs) will result in a plethora of applications ranging from intrabody health-monitoring to drug- delivery systems. With the development of miniature plasmonic signal sources, antennas and detectors, wireless communications among intrabody nanodevices will expectedly be enabled at both the Terahertz Band (0.1-10 THz) as well as optical frequencies (400-750 THz). This result motivates the analysis of the phenomena affecting the propagation of electromagnetic signals inside the human body. In this paper, a rigorous channel model for intrabody communication in iWNSNs is developed. The total path loss is computed by taking into account the combined effect of the spreading of the propagating wave, molecular absorption from human tissues, as well as scattering from both small and large body particles. The analytical results are validated by means of electromagnetic wave propagation simulations. Moreover, this paper provides the first framework necessitated for conducting link budget analysis between nanodevices operating within the human body. This analysis is performed by taking into account the transmitter power, medium path loss, and receiver sensitivity where both the THz and photonic devices are considered. The overall attenuation model of intrabody THz and optical frequency propagation facilitates the accurate design and practical deploy- ment of iWNSNs.