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Study of Light Propagation in Biological Tissues by Means of the Monte Carlo Simulation and Diffusion Method
, M.Sc. Thesis Sharif University of Technology ; Amjadi, Ahmad (Supervisor) ; Ansari, Mohammad Ali (Supervisor)
Abstract
The tissue characteristics are important for all kinds of medical laser applications in order to understand the interaction mechanisms between light and tissue. Knowledge about light transport in tissue is essential for cancer treatment and cancer diagnostic techniques. By having the diffused reflectance of a tissue we can determine its optical characteristics. In this thesis we have solved the inverse process. That is, we compute the diffused reflectance of a turbid media with pre-determined optical parameters. This problem can be solved using two methods: Monte Carlo simulation and diffusion method. Since Monte Carlo simulation is computationally very expensive, it is not used in medical...
Wavefront shaping using simulated annealing algorithm for focusing light through turbid media
, Article Progress in Biomedical Optics and Imaging - Proceedings of SPIE, 28 January 2018 through 1 February 2018 ; Volume 10494 , 2018 ; 16057422 (ISSN); 9781510614734 (ISBN) ; Salimi, F ; Mohammadian, N ; Fatima, A ; Rahimi Tabar, M. R ; Nasiri Avanaki, M. R ; SENO Medical Instruments, Inc.; The Society of Photo-Optical Instrumentation Engineers (SPIE) ; Sharif University of Technology
SPIE
2018
Abstract
In this research, we present the results of applying simulated annealing (SA) which is a heuristic optimization algorithm for focusing light through a turbid media. The performance of this algorithm on both phase optimization and amplitude optimization has been demonstrated. A guideline to set up the SA parameters is also suggested. The performance of SA algorithm in different levels of measurement noise has been also explored. The results showed that the SA algorithm performs effectively in measurement noises as high as 0.3(I0). © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only
A comparative study of optimization algorithms for wavefront shaping
, Article Journal of Innovative Optical Health Sciences ; Volume 12, Issue 4 , 2019 ; 17935458 (ISSN) ; Mohammadian, N ; Rahimi Tabar, M. R ; Manwar, R ; Avanaki, K ; Sharif University of Technology
World Scientific Publishing Co. Pte Ltd
2019
Abstract
By manipulating the phase map of a wavefront of light using a spatial light modulator, the scattered light can be sharply focused on a specific target. Several iterative optimization algorithms for obtaining the optimum phase map have been explored. However, there has not been a comparative study on the performance of these algorithms. In this paper, six optimization algorithms for wavefront shaping including continuous sequential, partitioning algorithm, transmission matrix estimation method, particle swarm optimization, genetic algorithm (GA), and simulated annealing (SA) are discussed and compared based on their efficiency when introduced with various measurement noise levels