Publications [#162115] of Nimmi Ramanujam

Papers Published

1. G. M. Palmer and N. Ramanujam, Monte Carlo-based inverse model for calculating tissue optical properties. Part I: Theory and validation on synthetic phantoms, Applied Optics, vol. 45 no. 5 (February, 2006), pp. 1062 -- 1071, ISSN 0003-6935
   (last updated on 2009/09/02)

   Abstract:
   A flexible and fast Monte Carlo-based model of diffuse reflectance has been developed for the extraction of the absorption and scattering properties of turbid media, such as human tissues. This method is valid for a wide range of optical properties and is easily adaptable to existing probe geometries, provided a single phantom calibration measurement is made. A condensed Monte Carlo method was used to speed up the for-ward simulations. This model was validated by use of two sets of liquid-tissue phantoms containing Nigrosin or hemoglobin as absorbers and polystyrene spheres as scatterers. The phantoms had a wide range of absorption (0-20 cm(-1)) and reduced scattering coefficients (7-33 cm(-1)). Mie theory and a spectrophotometer were used to determine the absorption and reduced scattering coefficients of the phantoms. The diffuse reflectance spectra of the phantoms were measured over a wavelength range of 350-850 nm. It was found that optical properties could be extracted from the experimentally measured diffuse reflectance spectra with an average error of 3\% or less for phantoms containing hemoglobin and 12\% or less for phantoms containing Nigrosin. (c) 2006 Optical Society of America.