Real-time method for fitting time-resolved reflectance and transmittance measurements with a monte carlo model.
نویسندگان
چکیده
An efficient method is proposed for the evaluation of theabsorption and the transport scattering coefficients from atime-resolved reflectance or transmittance distribution. Theprocedure is based on a library of Monte Carlo simulations and is fastenough to be used in a nonlinear fitting algorithm. Tests performedagainst both Monte Carlo simulations and experimental measurements ontissue phantoms show that the results are significantly better thanthose obtained by fitting the data with the diffusion approximation, especially for low values of the scattering coefficient. The methodrequires an a priori assumption on the value of theanisotropy factor g. Nonetheless, the transportscattering coefficient is rather independent of the exact knowledge ofthe g value within the range 0.7 < g < 0.9.
منابع مشابه
Reverse Monte Carlo Simulations of Light Pulse Propagation in Nonhomogeneous Media – Part Ii: Numerical Simulations
In the Part II of this study, the reverse Monte Carlo algorithm was applied to onedimensional, multi-layer media. The time-resolved reflectance exhibits a direct correlation between the signal magnitude and the travel time to the layer interface if the ballistic photons encounter a strongly scattering layer. Furthermore, it is found that even with a symmetric radiative property distribution in ...
متن کاملReal-time absorption and scattering characterization of slab-shaped turbid samples obtained by a combination of angular and spatially resolved measurements.
We present a fast and accurate method for real-time determination of the absorption coefficient, the scattering coefficient, and the anisotropy factor of thin turbid samples by using simple continuous-wave noncoherent light sources. The three optical properties are extracted from recordings of angularly resolved transmittance in addition to spatially resolved diffuse reflectance and transmittan...
متن کاملMeasurement of the optical properties of the skull in the wavelength range 650 - 950
AbslraeL The optical pmpeaies of samples of bone from pig skull have teen measured aver the wavelength range 650-950 nm. The scattering phase function was measured on thin samples of the bone using a goniometer, and a value for the mean cosine g, of the scattering angle, was calculaled. m e scattering and absorption coefficients, pr and pa were then determined from measurements of diffuse refle...
متن کاملDevelopement a simple point source model for Elekta SL-25 linear accelerator using MCNP4C Monte Carlo code
Background: Monte Carlo (MC) modeling of a linear accelerator is a prerequisite for Monte Carlo dose calculations in external beam radiotherapy. In this study, a simple and efficient model was developed for Elekta SL-25 linear accelerator using MCNP4C Monte Carlo code Materials and methods: The head of Elekta SL-25 linac was simulated for 6 and 18 MV photon beams using MCNP4C MC code. Energ...
متن کاملReference optical phantoms for diffuse optical spectroscopy. Part 1--Error analysis of a time resolved transmittance characterization method.
Development, production quality control and calibration of optical tissue-mimicking phantoms require a convenient and robust characterization method with known absolute accuracy. We present a solid phantom characterization technique based on time resolved transmittance measurement of light through a relatively small phantom sample. The small size of the sample enables characterization of every ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Applied optics
دوره 37 13 شماره
صفحات -
تاریخ انتشار 1998