FDTD Voxels-in-Cell Method With Debye Media

The Voxels-in-Cell (VIC) method was recently introduced to reduce the computational cost of the finite-difference time-domain (FDTD) method with objects composed of dielectric voxels. It relies on using an FDTD cell larger than the voxels, with eight or more voxels in each VIC cell. With the objective of using it in bio-electromagnetics applications, this article extends the VIC method to voxels filled with Debye media. Besides the theory and the algorithm of the extended VIC method, several numerical experiments are reported with a canonical object and with human body phantoms composed of voxels. The experiments show that the accuracy of the method is preserved while large reductions of the computational requirements can be achieved, especially the computational time can be reduced by about one order of magnitude.