Two Dimensional Angular Domain Optical Imaging in Biological Tissues PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Two Dimensional Angular Domain Optical Imaging in Biological Tissues PDF full book. Access full book title Two Dimensional Angular Domain Optical Imaging in Biological Tissues by Eldon Ng. Download full books in PDF and EPUB format.
Author: Eldon Ng
Publisher:
ISBN:
Category :
Languages : en
Pages : 254
Get Book Here
Book Description
Optical imaging is a modality that can detect optical contrast within a biological sample that is not detectable with other conventional imaging techniques. Optical transillumination images of tissue samples are degraded by optical scatter. Angular Domain Imaging (ADI) is an optical imaging technique that filters scattered photons based on the trajectory of the photons. Previous angular filters were limited to one-dimensional arrays greatly limiting the imaging capability of the system We have developed a 2D Angular Filter Array (AFA) that is capable of acquiring two-dimensional projection images of a sample. The AFA was constructed using rapid prototyping techniques. The contrast and the resolution of the AFA were evaluated. The results suggest that a 2D AFA can be used to acquire two-dimensional projection images of a sample with a reduced acquisition time compared to a scanning 1D AFA.
Author: Eldon Ng
Publisher:
ISBN:
Category :
Languages : en
Pages : 254
Get Book Here
Book Description
Optical imaging is a modality that can detect optical contrast within a biological sample that is not detectable with other conventional imaging techniques. Optical transillumination images of tissue samples are degraded by optical scatter. Angular Domain Imaging (ADI) is an optical imaging technique that filters scattered photons based on the trajectory of the photons. Previous angular filters were limited to one-dimensional arrays greatly limiting the imaging capability of the system We have developed a 2D Angular Filter Array (AFA) that is capable of acquiring two-dimensional projection images of a sample. The AFA was constructed using rapid prototyping techniques. The contrast and the resolution of the AFA were evaluated. The results suggest that a 2D AFA can be used to acquire two-dimensional projection images of a sample with a reduced acquisition time compared to a scanning 1D AFA.
Author: Fartash Vasefi
Publisher:
ISBN:
Category : Light
Languages : en
Pages : 550
Get Book Here
Book Description
Angular Domain Imaging (ADI) is a technique for performing optical imaging through highly scattering media. The basis for the technique is the micro-machined Angular Filter Array (AFA), which provides a parallel collection of micro-tunnels that accept ballistic/quasi-ballistic image-bearing photons and reject multiply scattered photons that result in image-destroying background noise. At high scattering levels, ADI image contrast declines due to the non-uniform scattered background light within the acceptance angle of the AFA. In this thesis, I developed multiple methodologies to correct for this problem and enhance ADI image contrast at higher scattering levels. These methodologies included combining ADI with time gating, polarization gating and employing image processing to estimate the background scattered light and use this information to enhance ADI image contrast and resolution. Furthermore, I conducted a comprehensive experimental investigation on a new AFA geometry designed to reduce the reflections within the micro-tunnels to reduce the unwanted background noise caused by multiply scattered photons. Building on previous studies with ADI in a trans-illumination configuration, I demonstrated that ADI could also be used to capture information-carrying photons from diffuse light back-reflected from tissue, where illumination was from the same side as the AFA. This mode of operation will enable applications of ADI where trans-illumination of samples is not possible. I also developed a tomographic ADI modality that rotated the sample and compiled ADI shadowgrams at each angle into a sinogram, followed by reconstruction of a transverse image with depth information. I also exploited the collimation detection capabilities of the AFA to extract photons emitted by a fluorophore embedded at depth within a turbid medium. The fluorescent imaging system using AFA offered higher resolution and contrast compared to a conventional lens and lens-pinhole fluorescent detection system in both in vitro and animal tests. Optical imaging with an AFA does not depend on coherence of the light source or the wavelength of light. Therefore, it is a promising candidate for multispectral/hyperspectral imaging to localize absorption and/or fluorescence in tissue and may have particular importance in cancer optical imaging.
Author: James G. Fujimoto
Publisher: Oxford University Press
ISBN: 0199722293
Category : Science
Languages : en
Pages : 435
Get Book Here
Book Description
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.
Author: Lingyan Shi
Publisher: CRC Press
ISBN: 1351797387
Category : Medical
Languages : en
Pages : 444
Get Book Here
Book Description
The use of light for probing and imaging biomedical media is promising for the development of safe, noninvasive, and inexpensive clinical imaging modalities with diagnostic ability. The advent of ultrafast lasers has enabled applications of nonlinear optical processes, which allow deeper imaging in biological tissues with higher spatial resolution. This book provides an overview of emerging novel optical imaging techniques, Gaussian beam optics, light scattering, nonlinear optics, and nonlinear optical tomography of tissues and cells. It consists of pioneering works that employ different linear and nonlinear optical imaging techniques for deep tissue imaging, including the new applications of single- and multiphoton excitation fluorescence, Raman scattering, resonance Raman spectroscopy, second harmonic generation, stimulated Raman scattering gain and loss, coherent anti-Stokes Raman spectroscopy, and near-infrared and mid-infrared supercontinuum spectroscopy. The book is a comprehensive reference of emerging deep tissue imaging techniques for researchers and students working in various disciplines.
Author: David D. Nolte
Publisher: Springer Science & Business Media
ISBN: 1461408903
Category : Science
Languages : en
Pages : 355
Get Book Here
Book Description
This book presents the fundamental physics of optical interferometry as applied to biophysical, biological and medical research. Interference is at the core of many types of optical detection and is a powerful probe of cellular and tissue structure in interfererence microscopy and in optical coherence tomography. It is also the root cause of speckle and other imaging artefacts that limit range and resolution. For biosensor applications, the inherent sensitivity of interferometry enables ultrasensitive detection of molecules in biological samples for medical diagnostics. In this book, emphasis is placed on the physics of light scattering, beginning with the molecular origins of refraction as light propagates through matter, and then treating the stochastic nature of random fields that ultimately dominate optical imaging in cells and tissue. The physics of partial coherence plays a central role in the text, with a focus on coherence detection techniques that allow information to be selectively detected out of incoherent and heterogeneous backgrounds. Optical Interferometry for Biology and Medicine is divided into four sections. The first covers fundamental principles, and the next three move up successive scales, beginning with molecular interferometry (biosensors), moving to cellular interferometry (microscopy), and ending with tissue interferometry (biomedical). An outstanding feature of the book is the clear presentation of the physics, with easy derivations of the appropriate equations, while emphasizing "rules of thumb" that can be applied by experimental researchers to give semi-quantitative predictions.
Author: Francesco S. Pavone
Publisher: Taylor & Francis
ISBN: 1439849153
Category : Science
Languages : en
Pages : 465
Get Book Here
Book Description
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
Author: Rongguang Liang
Publisher: Springer Science & Business Media
ISBN: 3642283918
Category : Science
Languages : en
Pages : 391
Get Book Here
Book Description
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.
Author: Ruikang K. Wang
Publisher: Taylor & Francis
ISBN: 1439895821
Category : Science
Languages : en
Pages : 726
Get Book Here
Book Description
Despite a number of books on biophotonics imaging for medical diagnostics and therapy, the field still lacks a comprehensive imaging book that describes state-of-the-art biophotonics imaging approaches intensively developed in recent years. Addressing this shortfall, Advanced Biophotonics: Tissue Optical Sectioning presents contemporary methods and
Author: Rongen Cheng
Publisher:
ISBN:
Category : Fluorescence
Languages : en
Pages : 0
Get Book Here
Book Description
Optical imaging through biological tissue has the significant challenge of scattering which degrades the image resolution and quality. Angular Domain Imaging (ADI) improves image quality by filtering out the scattered light in the biological tissue images based on the angular direction of photons. Using a newly developed solid fluorescing scattering phantom (SR = 17000, [mu [subscript s]]' = 48.4cm−1), this allows us to couple ADI with conventional fluorescence imaging technique. We created a new solid phantom which mimics human skin tissue with a patterned fluorescing collagen layer. These phantoms have stability over 6 months, much longer than traditional tissue phantoms. Monte Carlo simulations analyzed the angular filtration performance with the new low aspect ratio 2D-Collimating Arrays (2D-AFA) under shallow scattering depth fluorescing scenario. Applying the ADI filters, 2D-AFA and SpatioFrequency Filter (SFF), to the scattering sample, we detected resolution targets (200[mu]m - 400[mu]m) embedded inside the medium.
Author: Jorge Bouza Dominguez
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
In this thesis, a new time-dependent model for describing light propagation in biological media is proposed. The model is based on the simplified spherical harmonics approximation and is represented by a set of coupled parabolic partial differential equations (TD-pSPN equations). In addition, the model is extended for modeling the time-dependent response of fluorescent agents in biological tissues and the ensuing time-domain propagation of light therein. In a comparison with Monte Carlo simulations, it is shown that the TD-pSPN equations present unique features in its derivation that makes it a more accurate alternative to the diffusion equation (DE). The TD-pSPN model (for orders N > 1) outperforms the DE in the description of the propagation of light in near-nondiffusive media and in all the physical situations where DE fails. Often, only small orders of the SP N approximation are needed to obtain accurate results. A diffuse optical tomography (DOT) algorithm is also implemented based on the TD-pSPN equations as the forward model using constrained optimization methods. The algorithm uses time-dependent (TD) data directly. Such an approach is benefited from both the accuracy of the SPN models and the richness of TD data. In the calculation of the gradient of the objective function, a time-dependent adjoint differentiation method is introduced that reduces computation time. Several numerical experiments are performed for small geometry media with embedded inclusions that mimic small animal imaging. In these experiments, the values of the optical coefficients are varied within realistic bounds that are representative of those found in the range of the near-infrared spectrum, including high absorption values. Single and multi-parameter reconstructions (absorption and diffusion coefficients) are performed. The reconstructed images based on the TD-pSPN equations (N > 1) give better estimates of the optical properties of the media than the DE. On the other hand, crosstalk effects and small artifacts appeared in all the cases (more intense in the DE images). Comparatively, the reconstructed images show a lesser influence of these undesirable 'effects than other approaches found in the literature. The results suggest that the DOT algorithm based on the TD-pSPN model is an accurate alternative to the DE for imaging optical properties of biological media. These results directly benefict the fields of therapeutics and time-domain optical imaging of biological tissues. Particularly, the presented work is a decisive step in the elaboration of an optical scanner for small animal imaging at our lab. Thus, a positive impact in the areas of clinical diagnosis and biomedical research are expected.
