title: The finite element model for the propagation of light in scattering media: a direct method for domains with nonscattering regions.
abstract: We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems.
authors.affiliation: Department of Computer Science, University College London, England.
authors.forename: S R
authors.initials: SR
authors.lastname: Arridge
authors.forename: H
authors.initials: H
authors.lastname: Dehghani
authors.forename: M
authors.initials: M
authors.lastname: Schweiger
authors.forename: E
authors.initials: E
authors.lastname: Okada
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D008027:Light; D008962:Models, Theoretical; D009010:Monte Carlo Method; D012542:Scattering, Radiation