An electromagnetic model for biological tissue

TL;DR

This paper revisits and clarifies an electromagnetic model of biological tissue, emphasizing dielectric and conductive properties, and discusses the implications of experimental absorption data and numerical algorithms.

Contribution

It provides a detailed electromagnetic model of biological tissue, clarifies the mathematical framework, and addresses discrepancies in experimental absorption measurements.

Findings

Residual dielectric behavior aligns with electromagnetic theory

A damage-dependent attenuation coefficient explains conflicting absorption data

Numerical algorithms are detailed for model implementation

Abstract

This essay is a recapitulation of an earlier Kramers-Kronig analysis of biological tissue, published in 2010, "Kramers-Kronig analysis of biological skin". The intent is to both complement and bolster the antecedent analysis by furnishing supplemental clarification on the electromagnetic model employed and provide further technical details. Biological tissue is modeled a dielectric embedded in a conductor, which necessitates using both a quotient and product subspace to form a complete topological cover space. Discerning a suitable quotient enables decisive separation of tissue's dielectric behavior from excess conductivity. The residual dielectric behavior revealed conforms with expectations based upon electromagnetic theory and those commonly held for dielectric materials. An appreciation for conflicting experimental absorption measurements spanning the optical spectrum, reported for biological skin, engenders conceptualizing a damage dependent attenuation coefficient. Lastly, descriptive codes are provided for numerical algorithms implemented in the original analysis.