title: Diffuse light propagation in biological media by a time-domain parabolic simplified spherical harmonics approximation with ray-divergence effects.
abstract: We present a simplified spherical harmonics approximation for the time-domain radiative transfer equation including the source-divergence effect. This leads to a set of coupled partial differential equations (PDEs) of the parabolic type that model diffuse light propagation in biological-tissue-like media. We introduce a finite element approach for solving these PDEs, thereby obtaining the time-dependent spatial profile of the fluence. We compare the results with the diffusion equation and Monte Carlo simulations. The fluence obtained via our model is shown to reproduce well the Monte Carlo results in all cases and improves on the solution of the diffusion equation in homogeneous diffusive-defying media. Our solution also shows more sensitivity than the diffusion equation to changes in the absorption coefficient of small inclusions.
authors.affiliation: Laboratoire TomOptUS, Département de Génie Electrique et de Génie Informatique, Faculté de Génie, Université de Sherbrooke, 2500 boulevard Université, Sherbrooke, Québec J1K 2R1, Canada. Jorge.Bouza.Dominguez@USherbrooke.ca
authors.forename: Jorge
authors.initials: J
authors.lastname: Bouza Domínguez
authors.forename: Yves
authors.initials: Y
authors.lastname: Bérubé-Lauzière
mesh_terms: D000465:Algorithms; D004058:Diffusion; D007259:Infrared Rays; D008027:Light; D008954:Models, Biological; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D015203:Reproducibility of Results; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000379:methods*