Download or read book Design Fabrication And Testing Of A Versatile And Low Cost Diffuse Optical Tomographic Imaging System written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis reports the work done towards design and fabrication of a versatile and low cost, frequency domain DOT (Diffuse Optical Tomography) Imager. A design which uses only a single fiber for the source and a single fiber bundle for the detector is reported. From near the source, to diametrically opposite to the source, the detected intensity of scattered light varies by three to four orders in magnitude, depending on the tissue/phantom absorption and scattering properties. The photo multiplier tube (PMT) gain is controlled to operate it in the linear range, thus increasing the dynamic range of detection. Increasing the dynamic range by multi channel data acquisition is also presented. Arresting the oscillations of a stepper using a negative torque braking method is also adopted in this application for increasing the speed of data acquisition. The finite element method (FEM) for obtaining photon density solution to the transport equation and the model based iterative image reconstruction (MPBIIR) algorithm are developed for verifying the experimental prototype. Simulation studies presented towards the end of this thesis work provide insight into the nature of measurements. The optical absorption reconstructed images from the simulation, verified the validity of implementation of the reconstruction method for further reconstructions from data gathered from the developed imager. A single iteration of MOBIIR to segment the region of interest (ROI) using an homogeneous measurement estimate is presented. Using the single iteration MOBIIR to obtain a relatively more accurate starting value for the optical absorption coefficient, and the reconstruction results for data obtained from tissue mimicking solid epoxy-resin phantom with a single in-homogeneity inclusion is also presented to demonstrate the imager prototype.
Download or read book Development and Validation of Time domain Diffuse Optical Tomographic Imaging and Multiplexed Fluorescence Mediated Tomography written by Ying Mu and published by . This book was released on 2016 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse optical tomography (DOT) and fluorescence molecule tomography (FMT) are emerging as important optical imaging tools for clinical and biomedical research. Two major outstanding challenge in DOT and FMT are i) the relatively low imaging resolution, which results from the high degree of photon scatter through biological tissue, and ii) the inability to image multiple fluorescent targets in deep tissue ("multiplexing") due to the relatively narrow wavelength region within which light is less attenuated and effectively transmitted through bulk tissue. In this dissertation, we explored the use of time-domain DOT and FMT imaging to address these problems. First, time-resolved (TR) measurement of early arriving photons from a pulse laser was studied as a method for improving resolution in diffuse optical imaging. The underlying concept is photons that arrive first ("early") at a detector from a pulsed laser incident on bulk tissue have experienced fewer scattering events and taken relatively straight paths. We developed and tested a time-domain diffuse optical imaging system consisting of a femetosecond titanium: sapphire laser and fast, single photon avalanche photodiode (SPAD) detectors, that had an extremely fast temporal response time of 59 ps. We validated that the SPAD allowed measurement of photon-density sensitivity function that were 65% narrower than the temporally un-gated case at very early times. This exceeded the performance achieved previously with photomultiplier-based systems and approached the theoretical maximum predicted by time-resolved Monte Carlo simulations. Following this work, we then developed a complete SPAD-based DOT scanner, in which an array of SPADs were used. We validated performance of the system in cylindrical and irregular shaped optical phantoms of approximately small animal size. We were able to accurately reconstruct the size and position of up to 4 absorbing inclusions in diffusive media for the first time, with increasing image quality at earlier times. Next, we developed a time-resolved multiplexed fluorescence tomography system, which allowed us to measure extremely rich multi-spectral and temporal fluorescence data sets from diffusing media. In combination with a recently developed two-stage de-mixing and image reconstruction algorithm we are able to simultaneously image as many as four (and in theory 5) red and near-infrared fluorophores with closely overlapping spectral and temporal profiles, doubling the information throughput of FMT systems. This instrument also allowed us to account for the wavelength-dependency of optical properties in bulk biological tissue, which is a major challenge in biological imaging. The unique multiplexing imaging capabilities of this technology will allow us to study development of gliomas in small animal models in ongoing work in our group.
Download or read book The Design and Construction of a Frequency domain Optical Imaging System for Tissue Tomography written by David J. Rinehart and published by . This book was released on 1997 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Innovative Boundary Integral and Hybrid Methods for Diffuse Optical Imaging written by J. P. Elisee and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Diffuse Optical Imaging (DOI), the study of the propagation of Near Infra-Red (NIR) light in biological media, is an emerging method in medical imaging. Its state-of-the-art is non-invasive, versatile and reasonably inexpensive. In Diffuse Optical Tomography (DOT), the adaptation of numerical methods such as the Finite Element Method (FEM) and, more recently the Boundary Element Method (BEM), has allowed the treatment of complex problems, even for in vivo functional three-dimensional imaging. This work is the first attempt to combine these two methods in DOT. The BEM-FEM is designed to tackle layered turbid media problems. It focuses on the region of interest by restraining the reconstruction to it. All other regions are treated as piecewise-constant in a surface-integral approach. We validated the model in concentric spheres and found that it compared well with an analytical result. We then performed functional imaging of the neonate's motor cortex in vivo, in a reconstruction restricted to the brain, both with FEM and BEM-FEM. Another use of the BEM in DOI is also outlined. NIR Spectroscopy (NIRS) devices are particularly used in brain monitoring and Diffuse Optical Cortical Mapping (DOCM). Unfortunately, they are very often accompanied by rudimentary analysis of the data and the 3D appreciation of the problem is missed. The BEM DOCM developed in the current work represents an improvement, especially since a topographical representation of a motor activation in the cortex is clearly reconstructed in vivo. In the interest of computational speed an acceleration technique for the BEM has been developed. The Fast Multipole Method (FMM), which is based on the decomposition of Green's function on a basis of Bessel and Hankel functions, eases the evaluation of the BEM matrix, along with a faster calculation of the solutions.
Download or read book Photons Plus Ultrasound written by Alexander A. Oraevsky and published by . This book was released on 2012 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes Proceedings Vol. 7821
Download or read book Biophotonics for Medical Applications written by Igor Meglinski and published by Elsevier. This book was released on 2015-06-29 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biophotonics for Medical Applications presents information on the interface between laser optics and cell biology/medicine. The book discusses the development and application of photonic techniques that aid the diagnosis and therapeutics of biological tissues in both healthy and diseased states. Chapters cover the fundamental technologies used in biophotonics and a wide range of therapeutic and diagnostic applications. - Presents information on the interface between laser optics and cell biology/medicine - Discusses the development and application of photonic techniques which aid the diagnosis and therapeutics of biological tissues in both healthy and diseased states - Presents the fundamental technologies used in biophotonics and a wide range of therapeutic and diagnostic applications
Download or read book Visualizing Chemistry written by National Research Council and published by National Academies Press. This book was released on 2006-06-01 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientists and engineers have long relied on the power of imaging techniques to help see objects invisible to the naked eye, and thus, to advance scientific knowledge. These experts are constantly pushing the limits of technology in pursuit of chemical imagingâ€"the ability to visualize molecular structures and chemical composition in time and space as actual events unfoldâ€"from the smallest dimension of a biological system to the widest expanse of a distant galaxy. Chemical imaging has a variety of applications for almost every facet of our daily lives, ranging from medical diagnosis and treatment to the study and design of material properties in new products. In addition to highlighting advances in chemical imaging that could have the greatest impact on critical problems in science and technology, Visualizing Chemistry reviews the current state of chemical imaging technology, identifies promising future developments and their applications, and suggests a research and educational agenda to enable breakthrough improvements.
Download or read book Computed Tomography for Technologists Exam Review written by Lois Romans and published by Lippincott Williams & Wilkins. This book was released on 2018-07-23 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher's Note: Products purchased from 3rd Party sellers are not guaranteed by the Publisher for quality, authenticity, or access to any online entitlements included with the product. Computed Tomography for Technologists: Exam Review, Second Edition, is intended to be used as a companion to Computed Tomography for Technologists: A Comprehensive Text, Second Edition, and as a review of computed tomography on its own. This is an excellent resource for students preparing to take the advanced level certification exam offered by The American Registry of Radiologic Technologists (ARRT).
Download or read book Biomedical Engineering in Gastrointestinal Surgery written by Armin Schneider and published by Academic Press. This book was released on 2017-06-27 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomedical Engineering in Gastrointestinal Surgery is a combination of engineering and surgical experience on the role of engineering in gastrointestinal surgery. There is currently no other book that combines engineering and clinical issues in this field, while engineering is becoming more and more important in surgery. This book is written to a high technical level, but also contains clear explanations of clinical conditions and clinical needs for engineers and students. Chapters covering anatomy and physiology are comprehensive and easy to understand for non-surgeons, while technologies are put into the context of surgical disease and anatomy for engineers. The authors are the two most senior members of the Institute for Minimally Invasive Interdisciplinary Therapeutic Interventions (MITI), which is pioneering this kind of collaboration between engineers and clinicians in minimally invasive surgery. MITI is an interdisciplinary platform for collaborative work of surgeons, gastroenterologists, biomedical engineers and industrial companies with mechanical and electronic workshops, dry laboratories and comprehensive facilities for animal studies as well as a fully integrated clinical "OR of the future". - Written by the head of the Institute of Minimally Invasive Interdisciplinary Therapeutic Intervention (TUM MITI) which focusses on interdisciplinary cooperation in visceral medicine - Provides medical and anatomical knowledge for engineers and puts technology in the context of surgical disease and anatomy - Helps clinicians understand the technology, and use it safely and efficiently
Download or read book Optical Coherence Tomography written by Mark E. Brezinski and published by Elsevier. This book was released on 2006-08-25 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Coherence Tomography gives a broad treatment of the subject which will include 1)the optics, science, and physics needed to understand the technology 2) a description of applications with a critical look at how the technology will successfully address actual clinical need, and 3) a discussion of delivery of OCT to the patient, FDA approval and comparisons with available competing technologies. The required mathematical rigor will be present where needed but be presented in such a way that it will not prevent non-scientists and non-engineers from gaining a basic understanding of OCT and the applications as well as the issues of bringing the technology to the market. - Optical Coherence Tomography is a new medical high-resolution imaging technology which offers distinct advantages over current medical imaging technologies and is attracting a large number of researchers. - Provides non-scientists and non-engineers basic understanding of Optical Coherence Tomography applications and issues.
Download or read book The Photomultiplier Handbook written by A. G. Wright and published by Oxford University Press. This book was released on 2017 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Photomultipliers are extremely sensitive light detectors with the capability to detect single photons. In multiplying the charge produced by incident light by up to 100 million times, these devices are essential to a wide range of applications, from medical instrumentation to astronomical observations. This complete and authoritative guide will provide...a deeper understanding of the operating principles of these devices." -- Publisher's description, back cover.
Download or read book Biomedical Optical Imaging written by James G. Fujimoto and published by Oxford University Press. This book was released on 2009-04-22 with total page 435 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomedical optical imaging is a rapidly emerging research area with widespread fundamental research and clinical applications. This book gives an overview of biomedical optical imaging with contributions from leading international research groups who have pioneered many of these techniques and applications. A unique research field spanning the microscopic to the macroscopic, biomedical optical imaging allows both structural and functional imaging. Techniques such as confocal and multiphoton microscopy provide cellular level resolution imaging in biological systems. The integration of this technology with exogenous chromophores can selectively enhance contrast for molecular targets as well as supply functional information on processes such as nerve transduction. Novel techniques integrate microscopy with state-of-the-art optics technology, and these include spectral imaging, two photon fluorescence correlation, nonlinear nanoscopy; optical coherence tomography techniques allow functional, dynamic, nanoscale, and cross-sectional visualization. Moving to the macroscopic scale, spectroscopic assessment and imaging methods such as fluorescence and light scattering can provide diagnostics of tissue pathology including neoplastic changes. Techniques using light diffusion and photon migration are a means to explore processes which occur deep inside biological tissues and organs. The integration of these techniques with exogenous probes enables molecular specific sensitivity.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1996 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Schlieren and Shadowgraph Techniques written by G.S. Settles and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: Schlieren and shadowgraph techniques are basic and valuable tools in various scientific and engineering disciplines. They allow us to see the invisible: the optical inhomogeneities in transparent media like air, water, and glass that otherwise cause only ghostly distortions of our normal vision. These techniques are discussed briefly in many books and papers, but there is no up-to-date complete treatment of the subject before now. The book is intended as a practical guide for those who want to use these methods, as well as a resource for a broad range of disciplines where scientific visualization is important. The colorful 400-year history of these methods is covered in an extensive introductory chapter accessible to all readers.
Download or read book Ground based and Airborne Instrumentation for Astronomy IV written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alternatives for Landmine Detection written by Jacqueline MacDonald Gibson and published by Rand Corporation. This book was released on 2003 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the rate that government and nongovernmental organizations are clearing existing landmines, it will take 450-500 years to rid the world of them. Concerned about the slow pace of demining, the Office of Science and Technology asked RAND to assess potential innovative technologies being explored and to project what funding would be required to foster the development of the more promising ones. The authors of this report suggest that the federal government undertake a research and development effort to develop a multisensor mine detection system over the next five to eight years.
Download or read book Transmission Electron Microscopy written by C. Barry Carter and published by Springer. This book was released on 2016-08-24 with total page 543 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text is a companion volume to Transmission Electron Microscopy: A Textbook for Materials Science by Williams and Carter. The aim is to extend the discussion of certain topics that are either rapidly changing at this time or that would benefit from more detailed discussion than space allowed in the primary text. World-renowned researchers have contributed chapters in their area of expertise, and the editors have carefully prepared these chapters to provide a uniform tone and treatment for this exciting material. The book features an unparalleled collection of color figures showcasing the quality and variety of chemical data that can be obtained from today’s instruments, as well as key pitfalls to avoid. As with the previous TEM text, each chapter contains two sets of questions, one for self assessment and a second more suitable for homework assignments. Throughout the book, the style follows that of Williams & Carter even when the subject matter becomes challenging—the aim is always to make the topic understandable by first-year graduate students and others who are working in the field of Materials Science Topics covered include sources, in-situ experiments, electron diffraction, Digital Micrograph, waves and holography, focal-series reconstruction and direct methods, STEM and tomography, energy-filtered TEM (EFTEM) imaging, and spectrum imaging. The range and depth of material makes this companion volume essential reading for the budding microscopist and a key reference for practicing researchers using these and related techniques.
