Download or read book Assessment of Polarimetric Methodologies for Backscattered Imaging in Turbid Media written by Kamalakar Ambadipudi and published by . This book was released on 2009 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: "In optical imaging, the high random scattering of light in biological tissue can degrade the contrast of an image which could be a drawback in detection of tumors. Polarization based imaging has shown its capability in overcoming such drawbacks over the recent years. It depends on discrimination of randomly polarized light from weakly polarized light yielding an enhanced image contrast. The purpose of this research study was to investigate, compare and assess the imaging potential of two widely used techniques in the field of polarimetric imaging namely, Linear Polarimeter method (uses linearly polarized light) and Rotating Retarder Polarimeter method (uses circularly polarized light) to interrogate targets embedded in turbid biological media. This novel study may contribute to early detection of diseases and pathologies in biological tissues. The polarization properties of the backscattered light from a turbid medium containing a target submerged in a scattering solution were studied. A preclinical optical phantom was designed and the experiments were done in two phases, each phase corresponding to a different polarimetric technique. Specifically, a polystyrene cylinder was used as the target and the turbid medium was simulated by adding skim milk in volume percentage increments in both the phases. The first phase of experiments involved the Rotating Retarder Polarimeter method and the Polarimetric Measurement Matrix Reduction techniques. The images obtained by this method were processed by iv means of a data reduction algorithm, based on Polarimetric Measurement matrix method to calculate the Degree of Linear Polarization (DOLP) image and total intensity (S0) image. The second phase of experiments involved the Linear Polarimeter method. The resulting co-polarized and cross-polarized images from this method were processed to obtain Degree of Polarization (Rpol) images. Both of these experiments were performed using a backscattered polarimetric imaging system. The images obtained by both the techniques were analyzed by computing signal to background ratio (SBR) values and number of pixels detected as edges for every concentration of skim milk solution added to the surrounding medium of the target. The obtained images were then compared to determine the image quality. Experimental results from both these techniques showed that the DOLP images obtained by the Rotating Retarder Polarimeter method provide better contrast in terms of signal to background ratio (SBR) values and number of pixels detected as edges compared to Degree of Polarization (Rpol) images obtained by the linear Polarimeter method. Overall, the contributions of this study suggest that the interrogation of targets in turbid media using circularly polarized light exhibits superior imaging characteristics with respect to linearly polarized light interrogation."--Abstract.
Download or read book Detection of Polarimetric Signatures Using High efficiency Polarimetric Imaging Techniques written by Shadi Sumrain and published by . This book was released on 2005 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research involved the development of a polarimetric imaging algorithm used for selective detection of back scattered photons transmitted through a medium. The novelty of the algorithm was the use of Stokes parameters and Mueller matrix methods to enhance turbid media imaging. This in turn may replace time-gated imaging, optical heterodyne, and second-harmonic generation techniques. The first part consisted of exploring polarimetric phenomenology of 1-D and 2-D signals in a variety of experimental scenarios. Corner cube reflectors and arrays, photodiode windows, and camera zoom lenses were used as targets. Their polarization signatures, mainly reflected signal, optical cross section, line spread function (LSF) and modulation transfer function (MTF), were studied by applying Mueller matrix formalism. The second part consisted of exploring the applicability of multi-fusional multispectral active imaging principles. This was aimed at enhancing image quality under different harsh imaging conditions using arithmetic manipulations of images at more than one wavelength. Aluminum strips, bar patterns, and computer chips were used as underwater targets and interrogated with more than one wavelength of laser. The images were analyzed using the Mueller matrix formalism. The resulting polarized images, and multi-wavelength subtraction images, were studied for contrast differences. As a result of the study, we noted a few improvements. There was a visible increase in signal level when applying the degree of linear polarization (DOLP) algorithm. Since significant results were established using polarimetric signals, the polarimetric algorithm was used to test the impact on the size of a target's cross section. Using the range equation, we were able to improve the back scattered cross section of a corner cube and a camera zoom lens. DOLP was also able to improve the contrast of images taken with the lens focused, blurry, and out of focus. Similar results were observed for the LSF and MTF. For underwater imaging, polarimetric intensities improved even though scattered intensities decreased with increasing water cloudiness. However, the increase was not uniform. When comparing images of two separate wavelengths, it was noted that the contrast of the DOLP images was not significantly better than the non-polarimetric images. The image of the first Stokes parameter of each wavelength managed to improve contrast two fold or better. The subtraction of back scattered images also improved contrast.
Download or read book Multi band Polarization Imaging and Applications written by Yongqiang Zhao and published by Springer. This book was released on 2016-03-09 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the optical multi-band polarization imaging theory and the utilization of the multi-band polarimetric information for detecting the camouflage object and the optical hidden marker, and enhancing the visibility in bad weather and water. The book describes systematically and in detail the basic optical polarimetry theory; provides abundant multi-band polarimetric imaging experiment data; and indicates practical evaluation methods for designing the multi-band polarization imager, for analyzing and modeling the object’s multi-band polarization characteristics, and for enhancing the vision performance in scattering media. This book shows the latest research results of multi-band polarimetric vision, especially in camouflage object detection, optical hidden marker detection and multi-band polarimetric imagery fusion. From this book, readers can get a complete understanding about multi-band polarimetric imaging and its application in different vision tasks.
Download or read book Polarized Light Imaging for Assessment of Anisotropy in Turbid Media written by Sanaz Alali and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Assessment of anisotropy has many applications in tissue engineering and early detection of disease such as cancer or stroke. One of the emerging optical technologies for quantifying anisotropy in biological tissues is polarized light imaging. In this technique, the full Mueller matrix of the tissue is measured and then decomposed to yield optical retardance, which is proportional to the tissue anisotropy. The theory of polarized light imaging, its biomedical application and instrumentation are the subject of this thesis. To retrieve more information from the Mueller matrix, a quantitative analysis of generic turbid media's Mueller matrices beyond their decompositions was proposed. Two new metrics based on Mueller matrix were established in this thesis: 1) Tissue depolarization, calculated from the Mueller matrix, can be used to estimate its optical properties, and 2) Symmetry of the off-diagonal elements of a turbid medium's Mueller matrix can be used to detect the axial heterogeneity of anisotropy. Polarized light imaging, followed by Mueller matrix decomposition, was then successfully applied to locate the structural disorders induced by bladder outlet obstruction disease, in ex vivo functioning rat bladders. Motivated by the result of this study and to enable in vivo polarized light measurements of the bladder, a novel thin fiber based polarimetric probe which can measure the full Mueller matrix of the turbid media was suggested. Finally, to enhance the speed of the ex vivo examinations of biological tissues and avoid artifacts, a new rapid benchtop polarized light imaging system based on photoelastic modulators (PEM) and a charge-coupled device (CCD) was proposed and implemented. The demonstrated scheme does not involve using mechanically moving components and thus reduces systematic errors. This imaging system proved to be the fastest high resolution polarimetric characterization tool for imaging turbid media to date.
Download or read book High resolution Polarimetric Imaging Techniques for Space and Medical Applications written by Suman Shrestha and published by . This book was released on 2013 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the year 2012, there were approximately 226,160 cases of lung cancer and 160,340 deaths out of it as per the National Cancer Institute. There are mainly two types of lung cancer, small cell lung cancer and non-small cell lung cancer, of which 87% are diagnosed as non-small cell. A physical algorithm and a systematic study relating the morphological, chemical and metabolic properties of lung cancer to the physical and optical parameters of the polarimetric detection process are missing. Therefore, one of the purposes of the study is to explore the polarimetric phenomenology of near infrared light interaction with healthy and lung cancer monoline cells by using efficient polarimetric backscattering detection techniques. Preliminary results indicate that enhanced discrimination between healthy and different types of lung cancer cells can be achieved based on their backscattered intensities, Mueller matrix, diattenuation and depolarization properties. Also, various optical parameters like linear depolarization ratio and degree of linear polarization play an important role in discriminating healthy and different lung cancer cells. Specifically, the sizes of the nuclei of the cancer cells and the nucleus-to-cytoplasmic ratios appear to have potential impact on the detected polarimetric signatures leading to enhanced discrimination of lung cancer cells. The second work in this thesis has been done with the support of the Air Force Research Laboratory (AFRL). Polarimetric signals have always played an important role in the identification, discrimination and analysis of a material's optical properties. This work presents a novel remote sensing approach based on polarimetric fractal detection principles. Backscattered polarimetric signals contribution from different materials used in space applications have already been detected using a laboratory LADAR testbed and this thesis presents implememtation of the LADAR testbed and analysis techniques of these backscattered signals based on fractal analysis. Fractal dimension has been chosen as a measure for the discrimination purposes of these materials. The outcome of this thesis indicates that polarimetric fractal principles may enhance the capabilities of the LADAR for characterization and discrimination of different materials.
Download or read book Detection of Signal Parameters and Backscattering Polarimetric Imaging Signatures Using Molecular Optical Contrast Agents and Preclinical Liquid Phantoms written by Vandana Adya and published by . This book was released on 2008 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The main purpose of this study is to explore the potential of optically active molecules in conjunction with single pixel detectors and polarimetric techniques for early detection of tissue pathologies. Optical polarimetry can provide invaluable biological information based on molecular composition of the medium, structure, geometry, and metabolism. The preclinical phantom used was a rectangular plexiglass container and the experiments were carried out under backscattering detection geometry. A NIRVANA (Newfocus Inc., Model 2007, Santa Clara, CA, USA) auto balance detector was employed throughout the study. Initial readings were taken with water, and then aqueous solution of optically active molecules was added into it. The readings were obtained for the two states of polarization of light, parallel and perpendicular polarization. The signal-to-noise ratio and detective quantum efficiency (DQE) were calculated. The outcome of this study indicated an increase of the backscattered detected signal, signal-to-noise ratio, and the DQE of the imaging system, with increase in the concentration of optically active contrast agents. The results obtained were validated by performing linear regression analysis and paired t-test. The statistical analysis indicated increase in backscattered detected signal, signal to noise ratio, DQE and significant difference between the two states of polarization. This increase in the backscattered signal due to difference in the refractive index between the background and the object, leads to an increased contrast image that would assist in the early detection of tumor, other tissue pathologies, and biological structures."--Abstract.
Download or read book Handbook of Photonics for Biomedical Science written by Valery V. Tuchin and published by CRC Press. This book was released on 2010-05-18 with total page 863 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Photonics for Biomedical Science analyzes achievements, new trends, and perspectives of photonics in its application to biomedicine. With contributions from world-renowned experts in the field, the handbook describes advanced biophotonics methods and techniques intensively developed in recent years.Addressing the latest problems in
Download or read book Advances in Polarimetry and Ellipsometry Fundamentals and Applications written by Haofeng Hu and published by Frontiers Media SA. This book was released on 2022-10-17 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Imaging of Turbid Media Using Trajectory Filter Methods written by Nicholas Pfeiffer and published by . This book was released on 2009 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical imaging through biological tissues and other scattering media is challenging, as the scattered light creates an extremely high background noise level that makes it difficult to detect objects that are embedded within the media. This thesis examines a relatively unexplored method of separating scattered light from unscattered light that has application to optical imaging through turbid media. The method creates an optical filter that blocks photons based upon their exit trajectory direction. Such a trajectory filter can be used with a collimated beam that transmissively illuminates a scattering medium to create an imaging system in which a shadowgram is formed from those photons that pass through the filter and have a trajectory close to that of the collimated beam. Experiments have shown that such a system is effective up to measured optical depths of 18 to 21 and scattering ratios of 108 to 109 using both coherent and incoherent sources. A micromachined linear array of 50 m x 10 mm collimating holes was developed earlier as a photon trajectory filter and was used to successfully image through media in which the ratio of scattered to unscattered light is extremely high (>107). These results are much better than simple theory would predict. This thesis provides a theoretical basis for the trajectory filter system to allow its performance to be characterized and compared against other optical imaging methods, such as time-domain imaging. Using Monte Carlo simulations, it is found that the trajectory filter method is more effective than pathlength-based methods for imaging through turbid media with moderate levels of scattering, up to ̃optical depths, and that it can be combined with other imaging methods to further improve contrast. Advantages of the trajectory filter method include coherence and wavelength invariance and the ability to perform either wide beam, full-field or narrow beam, scanned imaging. Experimental results are presented for laser and incoherent beams using two types of trajectory filters: spatiofrequency and linear collimating hole array. It is found that the trajectory filter method offers a viable means of transmissively imaging through moderately scattering media at optical and near infrared wavelengths.
Download or read book Polarized Light in Biomedical Imaging and Sensing written by Jessica C. Ramella-Roman and published by Springer Nature. This book was released on 2022-11-14 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on biomedical applications of polarized light, covering instrumentation and modeling specific to the field. This will be the first book, written by leading researchers in the field, to tackle this important topic. Readers will learn the fundamentals of polarized light transport and how to develop instrumentation for clinical and preclinical studies. They will also become familiar with the latest advancement in data analysis and image processing for a variety of medical applications. The book is dedicated specifically to the biomedical community, including scientists, engineers, and physicians working on the development of instrumentation for clinical and preclinical use. Emphasizes biomedical imaging and sensing; Describes new computational approaches with examples; Provides detailed descriptions of novel instrumentation.
Download or read book Polarized Light written by Dennis H. Goldstein and published by CRC Press. This book was released on 2017-12-19 with total page 809 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polarized light is a pervasive influence in our world—and scientists and engineers in a variety of fields require the tools to understand, measure, and apply it to their advantage. Offering an in-depth examination of the subject and a description of its applications, Polarized Light, Third Edition serves as a comprehensive self-study tool complete with an extensive mathematical analysis of the Mueller matrix and coverage of Maxwell’s equations. Links Historical Developments to Current Applications and Future Innovations This book starts with a general description of light and continues with a complete exploration of polarized light, including how it is produced and its practical applications. The author incorporates basic topics, such as polarization by refraction and reflection, polarization elements, anisotropic materials, polarization formalisms (Mueller–Stokes and Jones) and associated mathematics, and polarimetry, or the science of polarization measurement. New to the Third Edition: A new introductory chapter Chapters on: polarized light in nature, and form birefringence A review of the history of polarized light, and a chapter on the interference laws of Fresnel and Arago—both completely re-written A new appendix on conventions used in polarized light New graphics, and black-and-white photos and color plates Divided into four parts, this book covers the fundamental concepts and theoretical framework of polarized light. Next, it thoroughly explores the science of polarimetry, followed by discussion of polarized light applications. The author concludes by discussing how our polarized light framework is applied to physics concepts, such as accelerating charges and quantum systems. Building on the solid foundation of the first two editions, this book reorganizes and updates existing material on fundamentals, theory, polarimetry, and applications. It adds new chapters, graphics, and color photos, as well as a new appendix on conventions used in polarized light. As a result, the author has re-established this book’s lofty status in the pantheon of literature on this important field.
Download or read book Single Pixel Polarimetric Imaging Through Scattering Media written by Cheryl Seow and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Optical Polarization in Biomedical Applications written by Valery V. Tuchin and published by Springer Science & Business Media. This book was released on 2006-10-12 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Polarization in Biomedical Applications introduces key developments in optical polarization methods for quantitative studies of tissues, while presenting the theory of polarization transfer in a random medium as a basis for the quantitative description of polarized light interaction with tissues. This theory uses the modified transfer equation for Stokes parameters and predicts the polarization structure of multiple scattered optical fields. The backscattering polarization matrices (Jones matrix and Mueller matrix) important for noninvasive medical diagnostic are introduced. The text also describes a number of diagnostic techniques such as CW polarization imaging and spectroscopy, polarization microscopy and cytometry. As a new tool for medical diagnosis, optical coherent polarization tomography is analyzed. The monograph also covers a range of biomedical applications, among them cataract and glaucoma diagnostics, glucose sensing, and the detection of bacteria.
Download or read book Photonics Volume 4 written by David L. Andrews and published by John Wiley & Sons. This book was released on 2015-02-27 with total page 576 pages. Available in PDF, EPUB and Kindle. Book excerpt: Discusses the basic physical principles underlying Biomedical Photonics, spectroscopy and microscopy This volume discusses biomedical photonics, spectroscopy and microscopy, the basic physical principles underlying the technology and its applications. The topics discussed in this volume are: Biophotonics; Fluorescence and Phosphorescence; Medical Photonics; Microscopy; Nonlinear Optics; Ophthalmic Technology; Optical Tomography; Optofluidics; Photodynamic Therapy; Image Processing; Imaging Systems; Sensors; Single Molecule Detection; Futurology in Photonics. Comprehensive and accessible coverage of the whole of modern photonics Emphasizes processes and applications that specifically exploit photon attributes of light Deals with the rapidly advancing area of modern optics Chapters are written by top scientists in their field Written for the graduate level student in physical sciences; Industrial and academic researchers in photonics, graduate students in the area; College lecturers, educators, policymakers, consultants, Scientific and technical libraries, government laboratories, NIH.
Download or read book Journal of the Optical Society of America written by and published by . This book was released on 2004 with total page 708 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2006 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt:
