A boundary integral method for a multi-layered problem

The single integral equation approach is used for the transmission problem associated with the Helmholtz equation involving three interfaces. This can be considered, in medical imaging applications, as a mathematical model for the human head, the three domains representing the brain, the skull and the scalp. We show that this leads to a Fredholm type of system of three equations involving three unknowns and present numerical results that illustrate the algorithm.