Pathloss modeling for in-body optical wireless communications

TL;DR

This paper develops a general pathloss model for in-body optical wireless communications by deriving and validating analytical expressions for tissue absorption coefficients, enabling improved design of nano-scale in-body networks.

Contribution

It introduces a novel analytical formula for tissue absorption coefficients, validated against experimental data, to enhance in-body optical communication modeling.

Findings

The analytical formula accurately models tissue absorption coefficients.

The model predicts pathloss and penetration depth in complex tissues.

Validation shows high agreement with experimental measurements.

Abstract

Optical wireless communications (OWCs) have been recognized as a candidate enabler of next generation in-body nano-scale networks and implants. The development of an accurate channel model capable of accommodating the particularities of different type of tissues is expected to boost the design of optimized communication protocols for such applications. Motivated by this, this paper focuses on presenting a general pathloss model for in-body OWCs. In particular, we use experimental measurements in order to extract analytical expressions for the absorption coefficients of the five main tissues' constitutions, namely oxygenated and de-oxygenated blood, water, fat, and melanin. Building upon these expressions, we derive a general formula for the absorption coefficient evaluation of any biological tissue. To verify the validity of this formula, we compute the absorption coefficient of complex tissues and compare them against respective experimental results reported by independent research works. Interestingly, we observe that the analytical formula has high accuracy and is capable of modeling the pathloss and, therefore, the penetration depth in complex tissues.