Download or read book A Study of Spectral Domain Optical Coherence Tomography and Photoacoustic Microscopy for Biometric and Biomedical Applications written by Mengyang Liu and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical coherence tomography (OCT) has been widely used in biomedical imaging ever since its introduction. However, the application of OCT for biometrics is relatively new. This thesis demonstrates the feasibility of applying a spectral domain optical coherence tomography (SD-OCT) system to fingertip biometric information retrieval. The results show that SD-OCT is capable of retrieving Level 3 fingertip information. Combined with traditional Level 1 and 2 fingerprint information, which can also be easily acquired by SD-OCT, the proposed application shows potential for ultra-secure scenarios. Photoacoustic microscopy (PAM) is another imaging modality gaining considerable interest in the past decade. Different than OCT, it employs ultrasound detection for optically induced thermal expansion in tissue. Bovine articulate cartilage samples are imaged with a single wavelength PAM system using India ink as a contrast agent. The same samples were also imaged with SD-OCT. Image analysis shows that PAM produces excellent contrast between intact and fibrillated regions in cartilage while SD-OCT visualizes topological changes with fine spatial resolution. A spectroscopic PAM system is also developed using a tunable source based on supercontinuum generation in a photonic crystal fiber. Imaging experiments of tissue phantoms demonstrate the ability to differentiate various chromophores with unique absorption characteristics. Another spectroscopic PAM system is currently being developed, where the tunable source is based on stimulated Raman scattering. This new system is being studied and some preliminary results are given to demonstrate its advantages over the supercontinuum approach.

Download or read book Optics and Ultrasound in Biomedicine Sensing Imaging and Therapy written by Chao Tian and published by Frontiers Media SA. This book was released on 2021-07-22 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectral Domain Optical Coherence Tomography A Practical Guide written by Dacosta Shaun, Rajendran Babu, Janakiraman P and published by JAYPEE BROTHERS PUBLISHERS. This book was released on with total page 265 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Guide to Interpreting Spectral Domain Optical Coherence Tomography written by Lumbroso Bruno, Rispoli Marco and published by JAYPEE BROTHERS PUBLISHERS. This book was released on with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book SWEPT SOURCE OPTICAL COHERENCE written by Luoqin Yu and published by Open Dissertation Press. This book was released on 2017-01-26 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Swept Source Optical Coherence Tomography System Development for Bioimaging Applications" by Luoqin, Yu, 俞罗琴, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Optical coherence tomography (OCT) is an imaging modality with strengths in high-resolution, label-free, and noninvasive, which strategically fills the gap between ultrasound and microscopy and is superior for some biomedical applications. Swept source OCT (SS-OCT) improves system simplicity and sensitivity compared to previous versions of time domain OCT (TD-OCT) because of a static reference mirror and has faster imaging speed compared to spectral domain OCT (SD-OCT) because of a single photodetector and the availability of high-repetition-rate broadband lasers. Furthermore, functional spectroscopic OCT (SOCT) analyzes materials according to their specific optical properties at different wavelengths. Thus, by utilizing an ultra-wide band OCT and analyzing the sub-band images, it provides us a spectroscopic way to recognize materials. These kinds of newly developed OCT systems are quite promising in clinical bioimaging applications. One of the most commonly used swept sources in SS-OCT systems is the Fourier domain mode-locked (FDML) laser. It has a narrow instantaneous linewidth that improves imaging range, a broad sweeping range that renders high resolution, fast building up time that enables fast scanning, and a proper output power. However, traditional FDML lasers have limited sweeping range because of a limited amplification window of the gain medium that is usually unable to achieve an ultra-wide wavelength range. It hinders its way in spectroscopic imaging applications. Nevertheless, multi-band illumination can break through the bandwidth limitation of single-band SOCT. Consequently, developing swept sources with various output wavelength ranges is of high interest. The FDML lasers with output at 1.0 m range are most suitable in water-rich tissues where water dispersion and absorption are minimized. Thus, 1.0 m FDML laser cavities are firstly proposed with different amplification schemes to compare their performances. Dual-and tri-band SS-OCT systems for SOCT application are further investigated for contrast enhancement and differentiation of materials, such as lipid and porcine artery. Not only the output wavelength ranges of swept sources are of big concern, the swept speed is another bottleneck yet to be surpassed, especially for endoscopic applications. As the mechanical inertia of FDML lasers will limit the fundamental A-scan rate to hundreds of kilohertz, an ultrafast mode-locked laser together with inertia-free optical time-stretch mechanism is a promising alternative for SS-OCT endoscopic application. It has long imaging range and allows an A-scan rate up to more than ten megahertz. We further demonstrated this kind of amplified optical time-stretch (AOT) OCT with extensional application by endoscopic imaging. In summary, the goal of this thesis is to develop and extend SS-OCT systems in different aspects for various bioimaging applications. The SS-OCT systems with different advantages are proposed for spectroscopic and endoscopic imaging. Subjects: Imaging systems in medicine Optical coherence tomography

Download or read book System Integration of Spectral Domain Optical Coherence Tomography with Virtual Detector Laser scanning Optical Resolution Photoacoustic Microscopy written by 李正綱 and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enhanced Spectral Domain Optical Coherence Tomography for Pathological and Functional Studies written by Zhijia Yuan and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optical Coherence Tomography written by Jianbing Xu and published by Open Dissertation Press. This book was released on 2017-01-27 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation, "Optical Coherence Tomography: From System Design to Spectroscopic Applications" by Jianbing, Xu, 徐鉴冰, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Optical coherence tomography (OCT), as a newly developed imaging modality, has attracted significant attention due to its capability to obtain the cross-sectional information of biological tissues in a non-invasive way, with resolution in the range of several micrometers. The third-generation swept source OCT (SS-OCT), is superior in the speed, imaging range and signal-to-noise ratio (SNR) compared with the previous time-domain OCT (TD-OCT) and spectral domain OCT (SD-OCT), and therefore forms our research focus. In this thesis, for the first time, I investigate the deployment of Fourier domain mode-locked (FDML) swept laser by utilizing the bismuth-based erbium doper fiber (Bi-EDF) with a sweeping bandwidth of 81nm achieved. Following, fiber Raman amplifier (FRA) is also investigated by employing multiple Raman pumps. The tuning range is 111.8nm, which is much larger than the previous reported Raman pumped FDML in the 1550nm region. Imaging was performed to validate the feasibility of the proposed schemes for the SS-OCT applications, respectively. In addition to the FDML swept laser cavity design, speckle noise reduction is also of great importance in OCT, which can significantly improve the visibility of the obtained OCT images. I demonstrate two different speckle reduction methods for OCT applications, which are superior in suppressing speckle noise and reserving the one-dimensional (1D) and two-dimensional (2D) signal information, respectively. Applying the proposed wavelet domain compounding (WDC) and contourlet shrinkage method to despeckle the OCT images, the visibility of the OCT images was significantly improved, with negligible edge preservation compromise. Spectroscopic information is also of interest to many researchers as it provides additional spectroscopic contrast, which on one hand, will improve the visualization of the images, and on the other hand, will enable the classification of different tissue types and help the process of discrimination between invasive and noninvasive tumors. Compared with our previous reported work about dual-band spectroscopic OCT based on optical parametric amplifier (OPA) to generate another idler band, which will be used as the second band for dual-band spectroscopic analysis, I further extend the dual-band spectroscopic OCT to the endoscopic applications, and investigate the dual-band FDML swept laser configuration based on a custom-designed dual-channel driver to synchronize the two different wavelength bands, centered at 1310 and 1550 nm, respectively. OCT Images for different bands are captured and post-processed by coding the spectral difference in different colors. In short, in this thesis, the investigations of OCT range from system design, speckle reduction to the spectroscopic applications. All these research efforts will extend the current FDML techniques for a wide range of SS-OCT applications. These schemes may be useful in OCT swept laser source build up, speckle noise reduction, and the extension of spectroscopic analysis. DOI: 10.5353/th_b5317037 Subjects: Optical coherence tomography

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 Biomedical Optical Imaging Technologies written by Rongguang Liang and published by Springer Science & Business Media. This book was released on 2012-09-21 with total page 391 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides an introduction to design of biomedical optical imaging technologies and their applications. The main topics include: fluorescence imaging, confocal imaging, micro-endoscope, polarization imaging, hyperspectral imaging, OCT imaging, multimodal imaging and spectroscopic systems. Each chapter is written by the world leaders of the respective fields, and will cover: principles and limitations of optical imaging technology, system design and practical implementation for one or two specific applications, including design guidelines, system configuration, optical design, component requirements and selection, system optimization and design examples, recent advances and applications in biomedical researches and clinical imaging. This book serves as a reference for students and researchers in optics and biomedical engineering.

Download or read book Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine written by and published by . This book was released on 2007 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Handbook of Full Field Optical Coherence Microscopy written by Arnaud Dubois and published by CRC Press. This book was released on 2016-10-14 with total page 743 pages. Available in PDF, EPUB and Kindle. Book excerpt: Full-field optical coherence microscopy (FF-OCM) is an imaging technique that provides cross-sectional views of the subsurface microstructure of semitransparent objects. The technology is based on low-coherence interference microscopy, which uses an area camera for en face imaging of the full-field illuminated object. FF-OCM benefits from the lateral imaging resolution of optical microscopy along with the capacity of optical axial sectioning at micrometer-scale resolution. The technique can be employed in diverse applications, in particular for non-invasive examination of biological tissues. This handbook is the first to be entirely devoted to FF-OCM. It is organized into four parts with a total of 21 chapters written by recognized experts and major contributors to the field. After a general introduction to FF-OCM, the fundamental characteristics of the technology are analyzed and discussed theoretically. The main technological developments of FF-OCM for improving the image acquisition speed and for endoscopic imaging are presented in part II. Extensions of FF-OCM for image contrast enhancement or functional imaging are reported in part III. The last part of the book provides an overview of possible applications of FF-OCM in medicine, biology, and materials science. A comprehensive compilation of self-contained chapters written by leading experts, this handbook is a definitive guide to the theoretical analyses, technological developments, and applications of FF-OCM. Using the rich information the book is replete with, a wide range of readers, from scientists and physicists to engineers as well as clinicians and biomedical researchers, can get a handle on the latest major advances in FF-OCM.

Download or read book Development of Spectral Domain Optical Coherence Tomography for in Vivo Functional Imaging of Biological Tissues written by Lin An and published by . This book was released on 2013 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical coherence tomography is a rapidly developing optical imaging modality capable of noninvasively providing depth resolved information of biological tissue at micrometer scale. Since its first report in 1991, it has made tremendous progress leading to successful applications in a number of fields, such as ophthalmology, gastroenterology, dermatology, dentistry, dermatology, cardiology, etc. According to [1], there are more than 15,000 OCT units that had been put into service in ophthalmic clinic by 2009, which represented approximately $1 billion market. The total amount paid by Medicare for OCT scans has increased from $1 billion per year in 2001 to $7 billion per year by 2008. The market size has kept growing in recent years. Reported in [2] by IBISWorld (an American research company), the OCT has achieved an annual growth rate of 27.4% since 2007. In 2012, the revenue is expected to be $478.4 million, which is 24.7% larger than last year. Despite the massive success, there are still several technical issues that need to be addressed, which could help the OCT technology to deliver even better imaging quality. In this thesis, we described several OCT technologies that can be used to double the imaging depth, realize functional vasculature imaging of biological tissue and increase the imaging speed of OCT system. Aim 1: Use of a scanner to introduce spatial frequency modulation to OCT spectral interferograms for in vivo full-range Fourier-domain optical coherence tomography. A novel method was developed that could easily introduce a modulation frequency onto the X-direction (i.e., B-scan) of the FDOCT scanning system, enabling full-range Fourier-domain Optical Coherence Tomography (frFDOCT). Compared to the conventional FDOCT system, the newly developed frFDOCT system can provide increased system sensitivity and deeper imaging depth. The previous technology that can achieve frFDOCT either needed multiple steps for data capturing, which is time consuming, or required additional components which increased the system's complexity. The newly developed method generates a modulation spatial frequency in the spectral interferogram by simply offsetting the probe beam at the X-scanner. In this way, the frFDOCT could be easily realized through applying a Hilbert transformation. Aim 2: Using optical micro-angiography to achieve in vivo volumetric imaging of vascular perfusion within human retina and choroids. Optical Micro-Angiography (OMAG) is a functional extension of FDOCT technology. It can achieve visualization of vasculature network of biological tissue. In order to apply the OMAG method to image vasculature map of human retina and choroid, a phase compensation algorithm was developed, which could minimize the motion artifacts generated by the movements of human eye and head. The original scanning protocol of OMAG method could only achieve ~2 mm x 2 mm scanning area on the retina, which is relatively small for clinical applications. To achieve large field of view of vasculature visualization of retina and choroid, multiple small areas of retina were sequentially scanned. After being processed, all the vasculature maps coming from small areas were stitched together to produce a vasculature map of the whole retina and choroid, which is comparable to Fluorescein Angiography. Aim 3: Developing ultrahigh sensitive optical micro-angiography to achieve micro vasculature imaging of biological tissue. Though the OMAG has been successfully applied for visualizing vasculature networks of different biological tissue, there are several problems that need to be solved, such as lower flow sensitivity, longer imaging time and so on. To improve the vasculature image quality, we developed ultrahigh sensitive OMAG (UHS-OMAG). Unlike conventional OMAG, UHS-OMAG applied the OMAG algorithm onto the slow direction of FDOCT scan (Y-direction). Because the time interval between adjacent B-frames is much longer than that between adjacent A-lines, UHS-OMAG can achieve much higher flow sensitivity compared to the conventional OMAG. In addition, the UHS-OMAG usually employed high frame rate (typically 300 frames per second) to achieve 3D scan, it cost much less time to finish one 3D scan compared to the traditional OMAG. However, when it was applied to visualize vasculature map of human tissue, the motion artifacts caused by the inevitable movements is still the biggest challenge. Based on the phase difference calculated from two adjacent B-frames, a new phase compensation algorithm was developed. The UHS-OMAG system was then applied onto human retina and skin to produce detailed micro vasculature networks. Aim 4: Developing ultrahigh speed Spectral Domain OCT system through sequentially controlling two high speed line scan CMOS cameras. Since the report of OCT technology, the imaging speed is always the hot topic along its development path. Though one branch of FDOCT technology, swept source OCT, can run at several megahertz, SSOCT is still not approved by FDA for human eye imaging. The development of spectral domain OCT is more attractive from a commercialization perspective. Two identical high speed line cameras were employed to build two home build high speed spectrometers. Through sequentially controlling the reading time period of two cameras, the imaging speed of the whole system could reach twice higher than the single camera system. The newly built 800 nm SDOCT system which can work at 500,000 Hz A-lines capturing speed was then used to achieve in vivo 3D imaging in both high speed and large field of view mode. In addition, through combining with the OMAG algorithm, the newly developed system is capable of providing detailed micro-vasculature imaging of human retina and optic nerve head.

Download or read book Optical Coherence Tomography written by Wolfgang Drexler and published by Springer Verlag. This book was released on 2008 with total page 1346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces optical coherence tomography, a high resolution imaging technique that enables non-invasive in vivo cross-sectional imaging of biological tissue. Covers optical and technological consderations as well biomedical and clinical perspectives.

Download or read book Photoacoustic Imaging and Spectroscopy written by Lihong V. Wang and published by CRC Press. This book was released on 2017-12-19 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoacoustics promises to revolutionize medical imaging and may well make as dramatic a contribution to modern medicine as the discovery of the x-ray itself once did. Combining electromagnetic and ultrasonic waves synergistically, photoacoustics can provide deep speckle-free imaging with high electromagnetic contrast at high ultrasonic resolution and without any health risk. While photoacoustic imaging is probably the fastest growing biomedical imaging technology, this book is the first comprehensive volume in this emerging field covering both the physics and the remarkable noninvasive applications that are changing diagnostic medicine. Bringing together the leading pioneers in this field to write about their own work, Photoacoustic Imaging and Spectroscopy is the first to provide a full account of the latest research and developing applications in the area of biomedical photoacoustics. Photoacoustics can provide functional sensing of physiological parameters such as the oxygen saturation of hemoglobin. It can also provide high-contrast functional imaging of angiogenesis and hypermetabolism in tumors in vivo. Discussing these remarkable noninvasive applications and so much more, this reference is essential reading for all researchers in medical imaging and those clinicians working at the cutting-edge of modern biotechnology to develop diagnostic techniques that can save many lives and just as importantly do no harm.

Download or read book Spectral Domain Optical Coherence Tomography Using a Microchip Laser pumped Photonic Crystal Fiber Supercontinuum Source written by Qi Zhao and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Coherence Tomography (OCT) is a well established biomedical imaging technique, which produces ultrahigh spatial resolution cross-sectional images of biological tissue in the range of a few millimeters. The axial resolution of OCT improves with a larger bandwidth optical source. Traditional OCT often uses a femtosecond laser as the broadband optical source. Recently, supercontinuum spectrum has been demonstrated by using the combination of femtosecond lasers and nonlinear effects of photonic crystal fiber. However, this source has fairly high cost. This thesis investigates OCT using a more cost effective source based on a microchip laser-pumped photonic crystal fiber. The Q-switched Nd:YAG microchip laser produces 0.6 ns duration pulses at 1064 nm with 8 mu-J of energy at a 6.6 kHz repetition rate. These pulses are sent through a photonic crystal fiber with a zero dispersion wavelength of 1040 nm. The generated supercontinuum pulses are coupled into a fiber-based spectral domain OCT system operating at a central wavelength of 800 nm. The axial scan rate is 6.6 kHz, where each scan is produced by a single supercontinuum pulse. Point spread function measurements show excellent resolution, but sensitivity is degraded by spectral fluctuations of individual supercontinuum pulses. Test images show less dynamic range compared to a Ti:Sapphire femtosecond laser based system. However, this supercontinuum source has potential for stroboscopic illumination in time-resolved low coherence interferometry.

Download or read book Coherence Domain Optical Methods and Optical Coherence Tomography in Biomedicine X written by Valeriĭ Viktorovich Tuchin and published by Society of Photo Optical. This book was released on 2006 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of SPIE present the original research papers presented at SPIE conferences and other high-quality conferences in the broad-ranging fields of optics and photonics. These books provide prompt access to the latest innovations in research and technology in their respective fields. Proceedings of SPIE are among the most cited references in patent literature.