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Direct physics-based implementation. Media like those found in human tissue are specified by: 1. Relative dielectric constant 2. Conductivity. Direct physics-based implementation. (. These are included in the FDTD formulation: . Note that the last term is written as the
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Direct physics-based implementation Media like those found in human tissue are specified by: 1. Relative dielectric constant 2. Conductivity
Direct physics-based implementation ( These are included in the FDTD formulation: Note that the last term is written as the average over two cells
Direct physics-based implementation This leads to the following C computer code: Specify the parameters in the cells: eaf = dt*sigma/(2*epsz*epsilon) ca[k] = (1. - eaf)/(1. + eaf) cb[k] =0.5/(epsilon*(1. + eaf)). Computer code in the main loop: ex[k] = ca[k]*ex[k] + cb[k] *( hy[k-1] - hy[k] ) hy[k] = hy[k] + 0.5*( ex[k] - ex[k+1] )
Direct physics-based implementation The following simulation shows an EM pulse propagating in free space and then striking a material with e = 5, s = 0.05. (Approximately the values for human fat or bone.)
The cells between 100 and 200 have been assigned the properties