Download or read book Quantification of Changes of Intensity and Attenuation Coefficient During Neural Activity Using Optical Coherence Tomography written by Md. Monirul Hasan and published by . This book was released on 2018 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nervous system, which receives information through the electrical signal to coordinate and disseminate information about the body and its environment, is an assembly of neurons. Current methods of detection of neural activity are based on electrophysiology, which requires direct or near direct contact, or fluorescence-based techniques, which require the introduction of reporter molecules, raising a concern of toxicity. Optical coherence tomography (OCT) detects neural activity by taking advantage of intrinsic structural changes that accompany neural activity without any exogenous agents. The phase-resolved OCT detected 10-30 nm swelling of axon during neural activity from the functionally stimulated compound eye of the horseshoe crab (limulus) by utilizing the phase-resolved measurement. There was a decrease of backscattered intensity during propagation of action potential due to change of scattering as well. Further study on in vitro murine brain slice showed the changes of the phase (or thickness change) as well as a decrease of back-reflected intensity during propagation of action potential. Above studies with pr-OCT were performed without scanning because scanning introduced phase noise, and the desired signal was buried under noise for the signal to noise ratio of 25~30 dB. However, spectral domain OCT was used to capture 3D volumetric intensity images during the neural activity in in vitro seizure mouse model after a period of baseline data. The average intensity of the hippocampal brain slice decreased by 10~18% from baseline during neural activity. Although intensity can separate neural activity from non-neural activity with 97.27% specificity and 97.60% sensitivity, it varies from experiment to experiment. Attenuation coefficient (μ), which quantifies how strongly a sample scatters and absorbs light is a constant for a sample, can solve the problem. During neural activities, there was a 10~15% decrease of μ. For both intensity and μ based method, there was a spatial correlation between optical changes and gold standard electrophysiology. Finally, quantified OCT intensity detected a localized action potential from CA1 of the hippocampal brain slice during ripple activation and -1% intensity threshold separated activity from non-activity.
Download or read book Progress Towards Detecting Neural Activity in Optical Coherence Tomography Using Phase written by Jasmine Kavan Shah and published by . This book was released on 2017 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Coherence Tomography (OCT) is non-invasive, real time optical imaging method based on low coherence interferometry with high resolution. It is capable of imaging microstructure by measuring the light backscattered from the sample. Under the AGI grant, I have built a Swept Source OCT (SS-OCT) / phase resolved OCT to detect the nanometer(nm) scale changes in the cell membrane that occur during membrane depolarization and Ion influx. This type of small changes can be seen using phase. Intensity is robust but is less sensitive to the small-scale changes whereas phase is highly sensitive. The noise level for phase difference quantification depends on the lateral motion, triggering of the wavelength mismatch and signal to noise ratio (SNR). To detect the nm scale changes phase noise should be minimum. The phase noise is inversely proportional to SNR. The SNR of the system should be maximum. The SS-OCT has swept source with sweep rate 100 kHz and it is not phase stable. It needs post processing algorithm to match the triggering wavelength to stabilize the phase. I wrote the code in GPU to reduce the computation time for post processing algorithm. Due to a few setbacks related to moving the system to a collaborating lab, the biological portion of my thesis work, trying to find the neural activity in the walking leg nerve of the Lobster using phase, was done with a spectral domain OCT (SD-OCT). To see any action potential change in the nerve I realigned the SD-OCT system with center wavelength to increase the SNR of the system and the sample arm with the nerve chamber (3D printed) to stimulate the nerve at one end and take the OCT image at the other end to see the action potential.
Download or read book High Resolution Imaging in Microscopy and Ophthalmology written by Josef F. Bille and published by Springer. This book was released on 2019-08-13 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.
Download or read book Optical Coherence Tomography written by Wolfgang Drexler and published by Springer Science & Business Media. This book was released on 2008-12-10 with total page 1346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical coherence tomography (OCT) is the optical analog of ultrasound imaging and is emerging as a powerful imaging technique that enables non-invasive, in vivo, high resolution, cross-sectional imaging in biological tissue. This book introduces OCT technology and applications not only from an optical and technological viewpoint, but also from biomedical and clinical perspectives. The chapters are written by leading research groups, in a style comprehensible to a broad audience.
Download or read book OCT Angiography in Retinal and Macular Diseases written by F. Bandello and published by Karger Medical and Scientific Publishers. This book was released on 2016-03-21 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: In only a short period of time, the innovative procedure of OCT angiography has become an essential macula imaging technique. Now that it is routinely used in clinical practice, the investigation of retinal and choroidal circulation is non-invasive, which significantly changes the professional’s approach to patients. In this volume, retina specialists and renowned experts share their experience with OCT angiography. They have included numerous color images and presented current ideas to form a base for further research and discussion. This book provides retina specialists, ophthalmologists, and researchers with a first glance at original research and clinical reports on this new methodology.
Download or read book Brain Mapping The Methods written by Arthur W. Toga and published by Academic Press. This book was released on 2002-10-06 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation of the functional architecture of the human brain using modern noninvasive imaging techniques is a rapidly expanding area of research. A proper knowledge of methodology is needed to appreciate the burgeoning literature in the field. This timely publication provides an excellent catalogue of the main techniques. The authors offer an invaluable analysis of mapping strategies and techniques, providing everything from the foundations to the major pitfalls and practical applications of the modern techniques used in neuroimaging. Contains over 1000 full color pages with more than 200 color figures. Spanning the methodological gamut from the molecular level to the whole brain while discussing anatomy, physiology, and pathology, as well as their integration, Brain Mapping: The Methods, Second Edition, brings the reader a comprehensive, well-illustrated and entirely readable description of the methods for brain mapping. Drs. Toga and Mazziotta provide everything from the foundations to the major pitfalls and practical applications of the technique by assembling an impressive group of experts, all widely known in their field, who contribute an outstanding set of chapters.
Download or read book Second Harmonic Generation Imaging written by Francesco S. Pavone and published by Taylor & Francis. This book was released on 2016-04-19 with total page 465 pages. Available in PDF, EPUB and Kindle. Book excerpt: Second-harmonic generation (SHG) microscopy has shown great promise for imaging live cells and tissues, with applications in basic science, medical research, and tissue engineering. Second Harmonic Generation Imaging offers a complete guide to this optical modality, from basic principles, instrumentation, methods, and image analysis to biomedical a
Download or read book Optical Coherence Tomography and Its Non medical Applications written by Michael Wang and published by BoD – Books on Demand. This book was released on 2020-05-27 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical coherence tomography (OCT) is a promising non-invasive non-contact 3D imaging technique that can be used to evaluate and inspect material surfaces, multilayer polymer films, fiber coils, and coatings. OCT can be used for the examination of cultural heritage objects and 3D imaging of microstructures. With subsurface 3D fingerprint imaging capability, OCT could be a valuable tool for enhancing security in biometric applications. OCT can also be used for the evaluation of fastener flushness for improving aerodynamic performance of high-speed aircraft. More and more OCT non-medical applications are emerging. In this book, we present some recent advancements in OCT technology and non-medical applications.
Download or read book Fundus Autofluorescence written by Noemi Lois and published by Lippincott Williams & Wilkins. This book was released on 2012-02-13 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: Featuring over 250 illustrations, this detailed full-color textbook provides up-to-date information on the use of fundus autofluorescence imaging in evaluation of retinal disease. Chapters describe the techniques available to image and quantify fundus autofluorescence and the autofluorescence patterns observed in the healthy eye and in various retinal diseases. Emphasis is on the value of fundus autofluorescence as a diagnostic and prognostic tool and its clinical utility in the context of other imaging techniques, such as fluorescein and indocyanine green angiography and optical coherence tomography. Each chapter also discusses the value of fundus autofluorescence in understanding the pathogenesis of the condition, and provides a comprehensive update on all aspects of the condition. A companion Website will offer the fully searchable text and an image bank.
Download or read book Physics of Biological Membranes written by Patricia Bassereau and published by Springer. This book was released on 2018-12-30 with total page 623 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book mainly focuses on key aspects of biomembranes that have emerged over the past 15 years. It covers static and dynamic descriptions, as well as modeling for membrane organization and shape at the local and global (at the cell level) scale. It also discusses several new developments in non-equilibrium aspects that have not yet been covered elsewhere. Biological membranes are the seat of interactions between cells and the rest of the world, and internally, they are at the core of complex dynamic reorganizations and chemical reactions. Despite the long tradition of membrane research in biophysics, the physics of cell membranes as well as of biomimetic or synthetic membranes is a rapidly developing field. Though successful books have already been published on this topic over the past decades, none include the most recent advances. Additionally, in this domain, the traditional distinction between biological and physical approaches tends to blur. This book gathers the most recent advances in this area, and will benefit biologists and physicists alike.
Download or read book Optics Letters written by and published by . This book was released on 2008 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Functional Magnetic Resonance Imaging written by Richard B. Buxton and published by Cambridge University Press. This book was released on 2009-08-27 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Magnetic Resonance Imaging (fMRI) has become a standard tool for mapping the working brain's activation patterns, both in health and in disease. It is an interdisciplinary field and crosses the borders of neuroscience, psychology, psychiatry, radiology, mathematics, physics and engineering. Developments in techniques, procedures and our understanding of this field are expanding rapidly. In this second edition of Introduction to Functional Magnetic Resonance Imaging, Richard Buxton – a leading authority on fMRI – provides an invaluable guide to how fMRI works, from introducing the basic ideas and principles to the underlying physics and physiology. He covers the relationship between fMRI and other imaging techniques and includes a guide to the statistical analysis of fMRI data. This book will be useful both to the experienced radiographer, and the clinician or researcher with no previous knowledge of the technology.
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 Medical Imaging Systems written by Andreas Maier and published by Springer. This book was released on 2018-08-02 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book gives a complete and comprehensive introduction to the fields of medical imaging systems, as designed for a broad range of applications. The authors of the book first explain the foundations of system theory and image processing, before highlighting several modalities in a dedicated chapter. The initial focus is on modalities that are closely related to traditional camera systems such as endoscopy and microscopy. This is followed by more complex image formation processes: magnetic resonance imaging, X-ray projection imaging, computed tomography, X-ray phase-contrast imaging, nuclear imaging, ultrasound, and optical coherence tomography.
Download or read book Tissue Optics written by Valery Tuchin and published by . This book was released on 2015 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt: This third edition of the biomedical optics classic Tissue Optics covers the continued intensive growth in tissue optics—in particular, the field of tissue diagnostics and imaging—that has occurred since 2007. As in the first two editions, Part I describes fundamentals and basic research, and Part II presents instrumentation and medical applications. However, for the reader’s convenience, this third edition has been reorganized into 14 chapters instead of 9. The chapters covering optical coherence tomography, digital holography and interferometry, controlling optical properties of tissues, nonlinear spectroscopy, and imaging have all been substantially updated. The book is intended for researchers, teachers, and graduate and undergraduate students specializing in the physics of living systems, biomedical optics and biophotonics, laser biophysics, and applications of lasers in biomedicine. It can also be used as a textbook for courses in medical physics, medical engineering, and medical biology.
Download or read book OCT and Imaging in Central Nervous System Diseases written by and published by . This book was released on 2020 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of OCT and Imaging in Central Nervous System Diseases offers updated state-of-the-art advances using optical coherence tomography (OCT) regrading neuronal loss within the retina. Detailed information on the OCT imaging and interpretation is provided for the evaluation of disease progression in numerous neurodegenerative disorders and as a biological marker of neuroaxonal injury. Covering disorders like multiple sclerosis, Parkinson's disease, Alzheimer's disease, intracranial hypertension, Friedreich's ataxia, schizophrenia, hereditary optic neuropathies, glaucoma, and amblyopia, readers will given insights into effects on the retina and the and optic nerve. Individual chapters are also devoted to OCT technique, new OCT technology in neuro-ophthalmology, OCT and pharmacological treatment, and the use of OCT in animal models. Similar to the first edition, this book is an excellent and richly illustrated reference for diagnosis of many retinal diseases and monitoring of surgical and medical treatment. OCT allows to study vision from of the retina to the optic tracts. Retinal axons in the retinal nerve fiber layer (RNFL) are non-myelinated until they penetrate the lamina cribrosa. Hence, the RNFL is an ideal structure for visualization of any process of neurodegeneration, neuroprotection, or regeneration. By documenting the ability of OCT to provide key information on CNS diseases, this book illustrates convincingly that the eye is indeed the "window to the brain".
Download or read book Progress in Brain Research written by J. P. Schadé and published by . This book was released on 1963 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:
