Modeling of light propagation in turbid medium using Monte Carlo simulation technique (original) (raw)
Related papers
1989
Abstruct-Using optical interaction coefficients typical of mammalian soft tissues in the red and near infrared regions of the spectrum, calculations of fluence-depth distributions, effective penetration depths and diffuse reflectance from two models of radiative transfer, diffusion theory, and Monte Carlo simulation are compared for a semi-infinite medium. The predictions from diffusion theory are shown to be increasingly inaccurate as the albedo tends to zero andlor the average cosine of scatter tends to unity.
Estimation of Photon Distribution within Biological Tissue Using Monte Carlo Simulation
BJSTR, 2017
This paper proposes a method of accurate light distribution using the Monte Carlo Simulation. In a Photodynamic Therapy (PDT), accurate light penetration depths are especially important as it is to be expected that applying too little light or too much light could result in inadequate tumor cell kill. The basic theory of this method is statistical iteration of simulation at phantom medium and can model any complex condition in biological tissues without any kind of tool. We performed Monte Carlo simulation with phantom layer having the optical properties of biological tissues. In this result, we could obtained the acceptable light dosimetry in biological phantom. Monte Carlo simulation is very powerful approaching model in radiation transfer for solving a variety of physical and mathematical problems. Recently, Photodynamic therapy (PDT) method becomes one of the methods to treat cancer using light. It is necessary to measure the light dosimetry in tissue to apply PDT for cancer to patient. To measure light dosimetry accurately, One must understand the light propagation in tissue and simulate with optical properties of target tissue. Optical coefficients are basically three interaction coefficients: absorption coefficient (μa), scattering coefficient (μs) and phase function [1-4]. It is very important to measure the correct optical properties in biological tissue to execute Monte Carlo simulation. If one want to perform with correct optical properties in simulation, he should have to measure the light doses in biological tissue.
IEEE Transactions on Biomedical Engineering, 1989
Abstruct-Using optical interaction coefficients typical of mammalian soft tissues in the red and near infrared regions of the spectrum, calculations of fluence-depth distributions, effective penetration depths and diffuse reflectance from two models of radiative transfer, diffusion theory, and Monte Carlo simulation are compared for a semi-infinite medium. The predictions from diffusion theory are shown to be increasingly inaccurate as the albedo tends to zero andlor the average cosine of scatter tends to unity.
A Monte Carlo model of light propagation in tissue
1989
ABSTRACT The Monte Carlo method is rapidly becoming the model of choice for simulating light transport in tissue. This paper provides all the details necessary for implementation of a Monte Carlo program. Variance reduction schemes that improve the efficiency of the Monte Carlo method are discussed. Analytic expressions facilitating convolution calculations for finite flat and Gaussian beams are included. Useful validation benchmarks are presented.
Monte Carlo methods for light propagation in biological tissues
Mathematical biosciences, 2015
Light propagation in turbid media is driven by the equation of radiative transfer. We give a formal probabilistic representation of its solution in the framework of biological tissues and we implement algorithms based on Monte Carlo methods in order to estimate the quantity of light that is received by a homogeneous tissue when emitted by an optic fiber. A variance reduction method is studied and implemented, as well as a Markov chain Monte Carlo method based on the Metropolis-Hastings algorithm. The resulting estimating methods are then compared to the so-called Wang-Prahl (or Wang) method. Finally, the formal representation allows to derive a non-linear optimization algorithm close to Levenberg-Marquardt that is used for the estimation of the scattering and absorption coefficients of the tissue from measurements.
Experimental verification and validation of a computer model for light-tissue interaction
Lasers in medical science, 2012
Laser light is frequently used in both diagnostics and treatment of patients. For any laser treatment to be effective it is important to deliver the correct dose at the treatment site. Human skin scatters and absorbs laser light in the visible wavelength region, which results in a decrease in fluence some distance into the skin. Computer simulations can be used to predict the fluence at the treatment site. Liquid and solid phantoms were prepared and the optical properties were measured. These values were then used as input values to a commercial software package simulating the different layers of skin representing phantoms. The transmission and reflected fractions of the different phantoms were measured with an integrating sphere and compared with the computer simulations. The results showed very good agreement with the measured values and the model can therefore be used with confidence to predict fluence at any treatment site inside the skin.
Modelling and Simulation of Light Absorption and Scattering in Biological Tissues
IFAC Proceedings Volumes, 1989
The new technique s for cancer healing call upon photo-chemical properties of new molecular composites such as hemato-porphyrin , Those techniques have inducted Photo-Chemiotherapy which use the most recent experience in matter of medical lasers, Contrary to the most classical and already well-known effects of current medi cal laser beams, the expertness of photo-chemical effects, needs the very precise knowledge of the light diffusion and absorption phenomenons in biological ti ssue s, in order to define an efficient dosimetry, Fundamental results of quantum theory allow to acceed to a simple model of the phenomenons and informatic tools allow to get a very sati sfying simulation from which very important results can be obtained, This paper deals with the first results of this study, led in very close collaboration between the two laboratories,
The Journal of social sciences and humanities, 2014
During the last few decades, a variety of medical scanning devices has been made and each, considering its unique features, has many applications. Methodology: In this paper efforts have been made to use Monte Carlo method to simulate the trajectory of the photons in biological tissue. New features were added to the Monte Carlo simulation. In this paper, of the most prominent features of simulation, changing the angle of incident beam to the tissue, selecting multilayer tissues, and choose the type of tissue could be named. In this study the results compared with others and the also the effect of anisotropy on the optical properties of the tissue were examined. Results: The results obtained with this code, even using a relatively small number of photons, compare favorably with those obtained elsewhere. The code can be changed so that the number of grid points is read as data input. It is worth emphasizing though that, with the option of running the Monte Carlo simulation directly from the code. Conclusion: the results obtained with the Monte Carlo simulation for different entry angles. No similar calculations have been found in the literature for a comparison to be possible. Our results seem to indicate that the diffuse reflectance and absorbance increases with decreasing angle while the transmittance decreases.