ECE532 Biomedical Optics © 1998 Steven L. Jacques, Scott A. Prahl Oregon Graduate Institute

Steady-State Monte Carlo

User settings

The user must select the settings that specify the simulation. Preset settings are listed for the following parameters:

• The optical properties of the medium:
  • absorption coefficient (mua) = µ_a [cm^-1]
  • scattering coefficient (mus) = µ_s [cm^-1]
  • anisotropy (g) = g [dimensionless]
  • refractive index (nt) = n_tissue [dimensionless]
• The simulation parameters:
  • number of photons to be launched (Nphotons).
  • total range over which the bins extend (radial_size)
  • number of bins for data output (NR). NR is preset to 100, and the array declarations declare the array sizes of Csph, Ccyl, and Cpla equal NR+1 = 101. If NR is changed, then the user must also change the array sizes declared in the variables section.

The albedo (albedo) and the incremental bin size (dr) are calculated for the user.

/**** INPUT
   Input the optical properties
   Input the bin and array sizes 
   Input the number of photons
*****/

mua         = 1.0;     /* cm^-1 */
mus         = 0.0;  /* cm^-1 */
g           = 0.90;  
nt          = 1.33;
Nphotons    = 10000; /* set number of photons in simulation */
radial_size = 3.0;   /* cm, total range over which bins extend */
NR          = 100;	 /* set number of bins.  */
   /* IF NR IS ALTERED, THEN USER MUST ALSO ALTER THE ARRAY DECLARATIONS */
   /* for Csph, Ccyl, Cpla TO A SIZE = NR + 1. */
dr          = radial_size/NR;  /* cm */
albedo      = mus/(mus + mua);