Download or read book Sensitivity Matrix Implementation in the Monte Carlo Package MBioICFO for the Simulation of Photon Migration in Tissues written by Niklas Gerdes and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An extension of the Monte Carlo method in diffuse optics was developed. Diffuse optical technology measures light absorption and scattering in human tissue. A sensitivity matrix has to be constructed to obtain structural information. It contains the sensitivities of the detected signal to absorption or scattering changes in different regions of the tissue. The existing MBioICFO simulation package was extended to allow the construction of the sensitivity matrix for perturbations in absorption. As opposed to prior implementations, the sensitivity matrix is determined in one simulation run and for arbitrary geometries. The new method was verified with analytical solutions for homogeneous media with infinite and semiinfinite boundary conditions. The method also enables determination of the sensitivity matrix for different detection times and in geometries obtained from MRI measurements. The program has shown appropriate computational efficiency with acceptable runtimes.
Download or read book Robust Monte Carlo Methods for Light Transport Simulation written by Eric Veach and published by . This book was released on 1998 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photon Migration in Tissues written by B. Chance and published by Springer Science & Business Media. This book was released on 1990-09-30 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is formulated from a number of presentations made at a one-day workshop on the subject of Photon Migration in Tissues. The meeting was held in Philadelphia at the University of Pennsylvania, April, 1988. The workshop was an impromptu effort to bring together scientists to discuss photon migration in animal tissues and appropriate models. The rapid emergence of the ideas of Townes and Schalow in their invention of the then called maser, now laser opened up completely unexpected possibilities for biomedical research. Timing of rapid biochemical reaction, identification of unstable intermediates, spectroscopy of short lived fluorescent states were all goals to be expected and achieved. At the same time continuous light spectroscopy of tissue slices and of the myocardium, and eventually of the brain have the to the the neonate emerged over years. Shifting red end of spectrum, Butler and Norris clearly showed how transparent plant materials and the human hand could be illuminated in this region and Jobsis applied their idea to the neonate brain using a multiwavelength technique.
Download or read book The Unified Monte Carlo Model of Photon Migration in Scattering Tissue like Media for the Needs of Biomedical Optics written by Alexander Doronin and published by . This book was released on 2014 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monte Carlo Simulation to Study Propagation of Light Through Biological Tissues written by Akshay Prabhu Verleker and published by . This book was released on 2011 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoacoustic Imaging is a non-invasive optical imaging modality used to image biological tissues. In this method, a pulsating laser illuminates a region of tissues to be imaged, which then generates an acoustic wave due to thermal volume expansion. This wave is then sensed using an acoustic sensor such as a piezoelectric transducer and the resultant signal is converted into an imaging using the back projection algorithm. Since different types of tissues have different photo-acoustic properties, this imaging modality can be used for imaging different types of tissues and bodily organ systems. This study aims at quantifying the process of light conversion into the acoustic signal. Light travels through tissues and gets attenuated (scattered or absorbed) or reflected depending on the optical properties of the tissues. The process of light propagation through tissues is studied using Monte Carlo simulation software which predicts the propagation of light through tissues of various shapes and with different optical properties. This simulation gives the resultant energy distribution due to light absorption and scattering on a voxel by voxel basis. The Monte Carlo code alone is not sufficient to validate the photon propagation. The success of the Monte Carlo code depends on accurate prediction of the optical properties of the tissues. It also depends on accurately depicting tissue boundaries and thus the resolution of the imaging space. Hence, a validation algorithm has been designed so as to recover the optical properties of the tissues which are imaged and to successfully validate the simulation results. The accuracy of the validation code is studied for various optical properties and boundary conditions. The results are then compared and validated with real time images obtained from the photoacoustic scanner. The various parameters for the successful validation of Monte Carlo method are studied and presented. This study is then validated using the algorithm to study the conversion of light to sound. Thus it is a significant step in the quantification of the photoacoustic effect so as to accurately predict tissue properties.
Download or read book Semina in Horto Botanico Acad Ludovic Gissensis anno 1849 collecta written by and published by . This book was released on 1849 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book MONTE CARLO MODELING OF DIFFUSE REFLECTANCE AND RAMAN SPECTROSCOPY IN BIOMEDICAL DIAGNOSTICS written by Alexander Pierre Dumont and published by . This book was released on 2020 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational modeling of light-matter interactions is a valuable approach for simulating photon paths in highly scattering media such as biological tissues. Monte Carlo (MC) models are considered to be the gold standard of implementation and can offer insights into light flux, absorption, and emission through tissues. Monte Carlo modeling is a computationally intensive approach, but this burden has been alleviated in recent years due to the parallelizable nature of the algorithm and the recent implementation of graphics processing unit (GPU) acceleration. Despite impressive translational applications, the relatively recent emergence of GPU-based acceleration of MC models can still be utilized to address some pressing challenges in biomedical optics beyond DOT and PDT. The overarching goal of the current dissertation is to advance the applications and abilities of GPU accelerated MC models to include low-cost devices and model Raman scattering phenomena as they relate to clinical diagnoses. The massive increase in computational capacity afforded by GPU acceleration dramatically reduces the time necessary to model and optimize optical detection systems over a wide range of real-world scenarios. Specifically, the development of simplified optical devices to meet diagnostic challenges in low-resource settings is an emerging area of interest in which the use of MC modeling to better inform device design has not yet been widely reported. In this dissertation, GPU accelerated MC modeling is utilized to guide the development of a mobile phone-based approach for diagnosing neonatal jaundice. Increased computational capacity makes the incorporation of less common optical phenomena such as Raman scattering feasible in realistic time frames. Previous Raman scattering MC models were simplistic by necessity. As a result, it was either challenging or impractical to adequately include model parameters relevant to guiding clinical translation. This dissertation develops a Raman scattering MC model and validates it in biological tissues. The high computational capacity of a GPU-accelerated model can be used to dramatically decrease the model's grid size and potentially provide an understanding of measured signals in Raman spectroscopy that span multiple orders of magnitude in spatial scale. In this dissertation, a GPU-accelerated Raman scattering MC model is used to inform clinical measurements of millimeter-scale bulk tissue specimens based on Raman microscopy images. The current study further develops the MC model as a tool for designing diffuse detection systems and expands the ability to use the MC model in Raman scattering in biological tissues.
