Substructuring Methods for 3-D BEM Multilayered Model for Diffuse Optical Tomography Problems

Diffuse optical tomography (DOT) is an emerging functional medical imaging modality with aims to recover the optical properties of biological tissue. The forward problem of the light propagation of DOT can be modelled in the frequency domain as a diffusion equation with Robin boundary conditions. In the case of multilayered geometries with piecewise constant parameters, the forward problem is equivalent to a set of coupled Helmholtz equations. In this paper we present a solution for the multilayered diffuse light propagation for a three-layer concentric sphere model using a series expansion method and for a general layered geometry using the boundary element method.