Sample records for biological imaging optical

  1. Molecular probes for nonlinear optical imaging of biological membranes (United States)

    Blanchard-Desce, Mireille H.; Ventelon, Lionel; Charier, Sandrine; Moreaux, Laurent; Mertz, Jerome


    Second-harmonic generation (SHG) and two-photon excited fluorescence (TPEF) are nonlinear optical (NLO) phenomena that scale with excitation intensity squared, and hence give rise to an intrinsic 3-dimensional resolution when used in microscopic imaging. TPEF microscopy has gained widespread popularity in the biology community whereas SHG microscopy promises to be a powerful tool because of its sensitivity to local asymmetry. We have implemented an approach toward the design of NLO-probes specifically adapted for SHG and/or TPEF imaging of biological membranes. Our strategy is based on the design of nanoscale amphiphilic NLO-phores. We have prepared symmetrical bolaamphiphilic fluorophores combining very high two-photon absorption (TPA) cross-sections in the visible red region and affinity for cellular membranes. Their incorporation and orientation in lipid membranes can be monitored via TPEF anisotropy. We have also prepared amphiphilic push-pull chromophores exhibiting both large TPA cross-sections and very large first hyperpolarizabilities in the near-IR region. These NLO-probes have proved to be particularly useful for imaging of biological membranes by simultaneous SHG and TPEF microscopy and offer attractive prospects for real-time imaging of fundamental biological processes such as adhesion, fusion or reporting of membrane potentials.

  2. Adaptive optics via pupil segmentation for high-resolution imaging in biological tissues. (United States)

    Ji, Na; Milkie, Daniel E; Betzig, Eric


    Biological specimens are rife with optical inhomogeneities that seriously degrade imaging performance under all but the most ideal conditions. Measuring and then correcting for these inhomogeneities is the province of adaptive optics. Here we introduce an approach to adaptive optics in microscopy wherein the rear pupil of an objective lens is segmented into subregions, and light is directed individually to each subregion to measure, by image shift, the deflection faced by each group of rays as they emerge from the objective and travel through the specimen toward the focus. Applying our method to two-photon microscopy, we could recover near-diffraction-limited performance from a variety of biological and nonbiological samples exhibiting aberrations large or small and smoothly varying or abruptly changing. In particular, results from fixed mouse cortical slices illustrate our ability to improve signal and resolution to depths of 400 microm.

  3. Biologically relevant photoacoustic imaging phantoms with tunable optical and acoustic properties (United States)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Joshua Pfefer, T.


    Established medical imaging technologies such as magnetic resonance imaging and computed tomography rely on well-validated tissue-simulating phantoms for standardized testing of device image quality. The availability of high-quality phantoms for optical-acoustic diagnostics such as photoacoustic tomography (PAT) will facilitate standardization and clinical translation of these emerging approaches. Materials used in prior PAT phantoms do not provide a suitable combination of long-term stability and realistic acoustic and optical properties. Therefore, we have investigated the use of custom polyvinyl chloride plastisol (PVCP) formulations for imaging phantoms and identified a dual-plasticizer approach that provides biologically relevant ranges of relevant properties. Speed of sound and acoustic attenuation were determined over a frequency range of 4 to 9 MHz and optical absorption and scattering over a wavelength range of 400 to 1100 nm. We present characterization of several PVCP formulations, including one designed to mimic breast tissue. This material is used to construct a phantom comprised of an array of cylindrical, hemoglobin-filled inclusions for evaluation of penetration depth. Measurements with a custom near-infrared PAT imager provide quantitative and qualitative comparisons of phantom and tissue images. Results indicate that our PVCP material is uniquely suitable for PAT system image quality evaluation and may provide a practical tool for device validation and intercomparison.

  4. High-resolution imaging of biological tissue with full-field optical coherence tomography (United States)

    Zhu, Yue; Gao, Wanrong


    A new full-field optical coherence tomography system with high-resolution has been developed for imaging of cells and tissues. Compared with other FF-OCT (Full-field optical coherence tomography, FF-OCT) systems illuminated with optical fiber bundle, the improved Köhler illumination arrangement with a halogen lamp was used in the proposed FF-OCT system. High numerical aperture microscopic objectives were used for imaging and a piezoelectric ceramic transducer (PZT) was used for phase-shifting. En-face tomographic images can be obtained by applying the five-step phase-shifting algorithm to a series of interferometric images which are recorded by a smart camera. Three-dimensional images can be generated from these tomographic images. Imaging of the chip of Intel Pentium 4 processor demonstrated the ultrahigh resolution of the system (lateral resolution is 0.8μm ), which approaches the theoretical resolution 0.7 μm× 0.5 μm (lateral × axial). En-face images of cells of onion show an excellent performance of the system in generating en-face images of biological tissues. Then, unstained pig stomach was imaged as a tissue and gastric pits could be easily recognized using FF-OCT system. Our study provides evidence for the potential ability of FFOCT in identifying gastric pits from pig stomach tissue. Finally, label-free and unstained ex vivo human liver tissues from both normal and tumor were imaged with this FFOCT system. The results show that the setup has the potential for medical diagnosis applications such liver cancer diagnosis.

  5. Diffuse reflectance spectroscopy and optical polarization imaging of in-vivo biological tissue (United States)

    Mora-Núñez, A.; Castillejos, Y.; García-Torales, G.; Martínez-Ponce, G.


    A number of optical techniques have been reported in the scientific literature as accomplishable methodologies to diagnose diseases in biological tissue, for instance, diffuse reflectance spectroscopy (DRS) and optical polarization imaging (OPI). The skin is the largest organ in the body and consists of three primary layers, namely, the epidermis (the outermost layer exposed to the world), the dermis, and the hypodermis. The epidermis changes from to site to site, mainly because of difference in hydration. A lower water content increase light scattering and reduce the penetration depth of radiation. In this work, two hairless mice have been selected to evaluate their skin features by using DRS and OPI. Four areas of the specimen body were chosen to realize the comparison: back, abdomen, tail, and head. From DRS, it was possible to distinguish the skin nature because of different blood irrigation at dermis. In the other hand, OPI shows pseudo-depolarizing regions in the measured Mueller images related to a spatially varying propagation of the scattered light. This provides information about the cell size in the irradiated skin.

  6. Complete Two-dimensional Muellermetric Imaging of Biological Tissue Using Heterodyned Optical Coherence Tomography

    CERN Document Server

    Liu, Xue; Shahriar, M S


    A polarization-sensitive optical coherence tomography system based on heterodyning and filtering techniques is built to perform Stokesmetric imaging of different layers of depths in a porcine tendon sample. The complete 4\\times4 backscattering Muellermetric images of one layer are acquired using such a system. The images reveal information indiscernible from a conventional OCT system.

  7. Optics of Biological Particles

    CERN Document Server

    Hoekstra, Alfons; Videen, Gorden


    This book covers the optics of single biological particles, both theory and experiment, with emphasis on Elastic Light Scattering and Fluorescence. It deals with the optics of bacteria (bio-aerosols), marine particles (selected phytoplankton communities) and red and white blood cells. Moreover, there are dedicated chapters on a general theory for scattering by a cell, and modelling and simulation of scattering by inhomogeneous biological cells. Finally, one chapter is dedicated to astro-biological signatures, discussing the possibilities for detecting non-terrestrial biological material. The volume has up-to-date discussions on new experimental and numerical techniques, and many examples of applications of these techniques in real-life systems, as used to detect and characterize e.g. biological warfare agents or human blood cells.

  8. Signal and Image Processing of Optical Coherence Tomography at 1310 nm Wavelength for Non Biological Samples

    Directory of Open Access Journals (Sweden)

    Yogesh Rao


    Full Text Available OCT is a recently developed optical interferometric technique for non-invasive diagnostic medical imaging in vivo; the most sensitive optical imaging modality.OCT finds its application in ophthalmology, blood flow estimation and cancer diagnosis along with many non biomedical applications. The main advantage of OCT is its high resolution which is in µm range and depth of penetration in mm range. Unlike other techniques like X rays and CT scan, OCT does not comprise any x ray source and therefore no radiations are involved. This research work discusses the basics of spectral domain OCT (SD-OCT, experimental setup, data acquisition and signal processing involved in OCT systems. Simulation of OCT involving modelling and signal processing, carried out on Lab VIEW platform has been discussed. Using the experimental setup, some of the non biomedical samples have been scanned. The signal processing and image processing of the scanned data was carried out in MATLAB and Lab VIEW, some of the results thus obtained have been discussed in the end.

  9. Section on High Resolution Optical Imaging (HROI) (United States)

    Federal Laboratory Consortium — The Section on High Resolution Optical Imaging (HROI) develops novel technologies for studying biological processes at unprecedented speed and resolution. Research...

  10. Optical image encryption topology. (United States)

    Yong-Liang, Xiao; Xin, Zhou; Qiong-Hua, Wang; Sheng, Yuan; Yao-Yao, Chen


    Optical image encryption topology is proposed based on the principle of random-phase encoding. Various encryption topological units, involving peer-to-peer, ring, star, and tree topologies, can be realized by an optical 6f system. These topological units can be interconnected to constitute an optical image encryption network. The encryption and decryption can be performed in both digital and optical methods.

  11. Optical imaging and spectroscopy

    CERN Document Server

    Brady, David J


    An essential reference for optical sensor system design This is the first text to present an integrated view of the optical and mathematical analysis tools necessary to understand computational optical system design. It presents the foundations of computational optical sensor design with a focus entirely on digital imaging and spectroscopy. It systematically covers: Coded aperture and tomographic imaging Sampling and transformations in optical systems, including wavelets and generalized sampling techniques essential to digital system analysis Geometric, wave, and statis

  12. Pushing the Envelope in Biological Imaging (United States)

    Betzig, Eric


    Optical microscopy has been instrumental in studies of the structure and function of biological systems for centuries. However, many questions at the forefront of molecular, cellular, and neurobiology remain beyond its current capabilities. I will discuss efforts in my group to extend these capabilities in areas such as superresolution optics, photodamage mediation, high speed volumetric imaging, and deep tissue imaging.

  13. Image processing and recognition for biological images. (United States)

    Uchida, Seiichi


    This paper reviews image processing and pattern recognition techniques, which will be useful to analyze bioimages. Although this paper does not provide their technical details, it will be possible to grasp their main tasks and typical tools to handle the tasks. Image processing is a large research area to improve the visibility of an input image and acquire some valuable information from it. As the main tasks of image processing, this paper introduces gray-level transformation, binarization, image filtering, image segmentation, visual object tracking, optical flow and image registration. Image pattern recognition is the technique to classify an input image into one of the predefined classes and also has a large research area. This paper overviews its two main modules, that is, feature extraction module and classification module. Throughout the paper, it will be emphasized that bioimage is a very difficult target for even state-of-the-art image processing and pattern recognition techniques due to noises, deformations, etc. This paper is expected to be one tutorial guide to bridge biology and image processing researchers for their further collaboration to tackle such a difficult target.

  14. Optomechatronics for Biomedical Optical Imaging: An Overview


    Cho Hyungsuck


    The use of optomechatronic technology, particularly in biomedical optical imaging, is becoming pronounced and ever increasing due to its synergistic effect of the integration of optics and mechatronics. The background of this trend is that the biomedical optical imaging for example in-vivo imaging related to retraction of tissues, diagnosis, and surgical operations have a variety of challenges due to complexity in internal structure and properties of biological body and the resulting optical ...

  15. Design and implementation of optical imaging and sensor systems for characterization of deep-sea biological camouflage (United States)

    Haag, Justin Mathew

    The visual ecology of deep-sea animals has long been of scientific interest. In the open ocean, where there is no physical structure to hide within or behind, diverse strategies have evolved to solve the problem of camouflage from a potential predator. Simulations of specific predator-prey scenarios have yielded estimates of the range of possible appearances that an animal may exhibit. However, there is a limited amount of quantitative information available related to both animal appearance and the light field at mesopelagic depths (200 m to 1000 m). To mitigate this problem, novel optical instrumentation, taking advantage of recent technological advances, was developed and is described in this dissertation. In the first half of this dissertation, the appearance of mirrored marine animals is quantitatively evaluated. A portable optical imaging scatterometer was developed to measure angular reflectance, described by the bidirectional reflectance distribution function (BRDF), of biological specimens. The instrument allows for BRDF capture from samples of arbitrary size, over a significant fraction of the reflectance hemisphere. Multiple specimens representing two species of marine animals, collected at mesopelagic depths, were characterized using the scatterometer. Low-dimensional parametric models were developed to simplify use of the data sets, and to validate the BRDF method. Results from principal component analysis confirm that BRDF measurements can be used to study intra- and interspecific variability of mirrored marine animal appearance. Collaborative efforts utilizing the BRDF data sets to develop physically-based scattering models are underway. In the second half of this dissertation, another key part of the deep-sea biological camouflage problem is examined. Two underwater radiometers, capable of low-light measurements, were developed to address the lack of available information related to the deep-sea light field. Quantitative comparison of spectral

  16. Optical interferometry for biology and medicine

    CERN Document Server

    Nolte, David D


    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 ...

  17. Optomechatronics for Biomedical Optical Imaging: An Overview

    Directory of Open Access Journals (Sweden)

    Cho Hyungsuck


    Full Text Available The use of optomechatronic technology, particularly in biomedical optical imaging, is becoming pronounced and ever increasing due to its synergistic effect of the integration of optics and mechatronics. The background of this trend is that the biomedical optical imaging for example in-vivo imaging related to retraction of tissues, diagnosis, and surgical operations have a variety of challenges due to complexity in internal structure and properties of biological body and the resulting optical phenomena. This paper addresses the technical issues related to tissue imaging, visualization of interior surfaces of organs, laparoscopic and endoscopic imaging and imaging of neuronal activities and structures. Within such problem domains the paper overviews the states of the art technology focused on how optical components are fused together with those of mechatronics to create the functionalities required for the imaging systems. Future perspective of the optical imaging in biomedical field is presented in short.

  18. Optical imaging and metrology

    CERN Document Server

    Osten, Wolfgang


    A comprehensive review of the state of the art and advances in the field, while also outlining the future potential and development trends of optical imaging and optical metrology, an area of fast growth with numerous applications in nanotechnology and nanophysics. Written by the world's leading experts in the field, it fills the gap in the current literature by bridging the fields of optical imaging and metrology, and is the only up-to-date resource in terms of fundamental knowledge, basic concepts, methodologies, applications, and development trends.

  19. Optical probes in biology

    CERN Document Server

    Zhang, Jin; Schultz, Carsten


    Introduction and BasicsEngineering of Optimized Fluorescent Proteins: An Overview from a Cyan and FRET Perspective Lindsay Haarbosch, Joachim Goedhart, Mark A. Hink, Laura van Weeren, Daphne S. Bindels, and Theodorus W.J. GadellaFluorescent Imaging Techniques: FRET and Complementary Methods Stefan Terjung and Yury BelyaevTracking: Sensors for Tracking BiomoleculesProtein-Based Calcium Sensors Thomas Thestrup and Oliver GriesbeckMonitoring Membrane Lipids with Protein Domains Expressed in Living Cells Peter Varnai

  20. Optical imaging. Expansion microscopy. (United States)

    Chen, Fei; Tillberg, Paul W; Boyden, Edward S


    In optical microscopy, fine structural details are resolved by using refraction to magnify images of a specimen. We discovered that by synthesizing a swellable polymer network within a specimen, it can be physically expanded, resulting in physical magnification. By covalently anchoring specific labels located within the specimen directly to the polymer network, labels spaced closer than the optical diffraction limit can be isotropically separated and optically resolved, a process we call expansion microscopy (ExM). Thus, this process can be used to perform scalable superresolution microscopy with diffraction-limited microscopes. We demonstrate ExM with apparent ~70-nanometer lateral resolution in both cultured cells and brain tissue, performing three-color superresolution imaging of ~10(7) cubic micrometers of the mouse hippocampus with a conventional confocal microscope.

  1. Acousto-optic laser optical feedback imaging

    CERN Document Server

    Jacquin, Olivier; Lacot, Eric; Hugon, Olivier; De Chatellus, Hugues Guillet; François, Ramaz


    We present a photon noise and diffraction limited imaging method combining the imaging laser and ultrasonic waves. The laser optical feedback imaging (LOFI) technique is an ultrasensitive imaging method for imaging objects through or embedded within a scattering medium. However, LOFI performances are dramatically limited by parasitic optical feedback occurring in the experimental setup. In this work, we have tagged the ballistic photons by an acousto-optic effect in order to filter the parasitic feedback effect and to reach the theoretical and ultimate sensitivity of the LOFI technique. We present the principle and the experimental setup of the acousto-optic laser optical feedback imaging (AO-LOFI) technique, and we demonstrate the suppression of the parasitic feedback.

  2. All-optically integrated multimodality imaging system: combined photoacoustic microscopy, optical coherence tomography, and fluorescence imaging (United States)

    Chen, Zhongjiang; Yang, Sihua; Xing, Da


    We have developed a multimodality imaging system by optically integrating all-optical photoacoustic microscopy (AOPAM), optical coherence tomography (OCT) and fluorescence microscopy (FLM) to provide complementary information including optical absorption, optical back-scattering and fluorescence contrast of biological tissue. By sharing the same low-coherence Michelson interferometer, AOPAM and OCT could be organically optically combined to obtain the absorption and scattering information of the biological tissues. Also, owing to using the same laser source and objective lens, intrinsically registered photoacoustic and fluorescence signals are obtained to present the radiative and nonradiative transition process of absorption. Simultaneously photoacoustic angiography, tissue structure and fluorescence molecular in vivo images of mouse ear were acquired to demonstrate the capabilities of the optically integrated trimodality imaging system, which can present more information to study tumor angiogenesis, vasculature, anatomical structure and microenvironments in vivo.

  3. Using electron microscopy to calculate optical properties of biological samples


    Wu, Wenli; Radosevich, Andrew J.; Eshein, Adam; Nguyen, The-Quyen; Yi, Ji; Cherkezyan, Lusik; Roy, Hemant K.; Szleifer, Igal; Backman, Vadim


    The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy...

  4. Fiber optic sensing and imaging

    CERN Document Server


    This book is designed to highlight the basic principles of fiber optic imaging and sensing devices. The editor has organized the book to provide the reader with a solid foundation in fiber optic imaging and sensing devices. It begins with an introductory chapter that starts from Maxwell’s equations and ends with the derivation of the basic optical fiber characteristic equations and solutions (i.e. fiber modes). Chapter 2 reviews most common fiber optic interferometric devices and Chapter 3 discusses the basics of fiber optic imagers with emphasis on fiber optic confocal microscope. The fiber optic interferometric sensors are discussed in detail in chapter 4 and 5. Chapter 6 covers optical coherence tomography and goes into the details of signal processing and systems level approach of the real-time OCT implementation. Also useful forms of device characteristic equations are provided so that this book can be used as a reference for scientists and engineers in the optics and related fields.

  5. Optical image encryption based on diffractive imaging. (United States)

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R


    In this Letter, we propose a method for optical image encryption based on diffractive imaging. An optical multiple random phase mask encoding system is applied, and one of the phase-only masks is selected and laterally translated along a preset direction during the encryption process. For image decryption, a phase retrieval algorithm is proposed to extract a high-quality plaintext. The feasibility and effectiveness of the proposed method are demonstrated by numerical results. The proposed method can provide a new strategy instead of conventional interference methods, and it may open up a new research perspective for optical image encryption.

  6. Nonlinear spectral imaging of biological tissues (United States)

    Palero, J. A.


    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal. Because biological intrinsic emission is generally very weak and extends from the ultraviolet to the visible spectral range, a broad-spectral range and high sensitivity 3D spectral imaging system is developed. Imaging the spectral characteristics of the biological intrinsic emission reveals the structure and biochemistry of the cells and extra-cellular components. By using different methods in visualizing the spectral images, discrimination between different tissue structures is achieved without the use of any stain or fluorescent label. For instance, RGB real color spectral images of the intrinsic emission of mouse skin tissues show blue cells, green hair follicles, and purple collagen fibers. The color signature of each tissue component is directly related to its characteristic emission spectrum. The results of this study show that skin tissue nonlinear intrinsic emission is mainly due to the autofluorescence of reduced nicotinamide adenine dinucleotide (phosphate), flavins, keratin, melanin, phospholipids, elastin and collagen and nonlinear Raman scattering and second-harmonic generation in Type I collagen. In vivo time-lapse spectral imaging is implemented to study metabolic changes in epidermal cells in tissues. Optical scattering in tissues, a key factor in determining the maximum achievable imaging depth, is also investigated in this work.

  7. Plasmonics Meets Biology through Optics

    Directory of Open Access Journals (Sweden)

    Luciano De Sio


    Full Text Available Plasmonic metallic nanoparticles (NPs represent a relevant class of nanomaterials, which is able to achieve light localization down to nanoscale by exploiting a phenomenon called Localized Plasmon Resonance. In the last few years, NPs have been proposed to trigger DNA release or enhance ablation of diseased tissues, while minimizing damage to healthy tissues. In view of the therapeutic relevance of such plasmonic NPs; a detailed characterization of the electrostatic interaction between positively charged gold nanorods (GNRs and a negatively charged whole-genome DNA solution is reported. The preparation of the hybrid biosystem has been investigated as a function of DNA concentration by means of ζ-potential; hydrodynamic diameter and gel electrophoresis analysis. The results have pointed out the specific conditions to achieve the most promising GNRs/DNA complex and its photo-thermal properties have been investigated. The overall study allows to envisage the possibility to ingeniously combine plasmonic and biological materials and, thus, enable design and development of an original non invasive all-optical methodology for monitoring photo-induced temperature variation with high sensitivity.

  8. Image processing for optical mapping. (United States)

    Ravindran, Prabu; Gupta, Aditya


    Optical Mapping is an established single-molecule, whole-genome analysis system, which has been used to gain a comprehensive understanding of genomic structure and to study structural variation of complex genomes. A critical component of Optical Mapping system is the image processing module, which extracts single molecule restriction maps from image datasets of immobilized, restriction digested and fluorescently stained large DNA molecules. In this review, we describe robust and efficient image processing techniques to process these massive datasets and extract accurate restriction maps in the presence of noise, ambiguity and confounding artifacts. We also highlight a few applications of the Optical Mapping system.

  9. Optical imaging probes in oncology. (United States)

    Martelli, Cristina; Lo Dico, Alessia; Diceglie, Cecilia; Lucignani, Giovanni; Ottobrini, Luisa


    Cancer is a complex disease, characterized by alteration of different physiological molecular processes and cellular features. Keeping this in mind, the possibility of early identification and detection of specific tumor biomarkers by non-invasive approaches could improve early diagnosis and patient management.Different molecular imaging procedures provide powerful tools for detection and non-invasive characterization of oncological lesions. Clinical studies are mainly based on the use of computed tomography, nuclear-based imaging techniques and magnetic resonance imaging. Preclinical imaging in small animal models entails the use of dedicated instruments, and beyond the already cited imaging techniques, it includes also optical imaging studies. Optical imaging strategies are based on the use of luminescent or fluorescent reporter genes or injectable fluorescent or luminescent probes that provide the possibility to study tumor features even by means of fluorescence and luminescence imaging. Currently, most of these probes are used only in animal models, but the possibility of applying some of them also in the clinics is under evaluation.The importance of tumor imaging, the ease of use of optical imaging instruments, the commercial availability of a wide range of probes as well as the continuous description of newly developed probes, demonstrate the significance of these applications. The aim of this review is providing a complete description of the possible optical imaging procedures available for the non-invasive assessment of tumor features in oncological murine models. In particular, the characteristics of both commercially available and newly developed probes will be outlined and discussed.

  10. Multiplane 3D superresolution optical fluctuation imaging

    CERN Document Server

    Geissbuehler, Stefan; Godinat, Aurélien; Bocchio, Noelia L; Dubikovskaya, Elena A; Lasser, Theo; Leutenegger, Marcel


    By switching fluorophores on and off in either a deterministic or a stochastic manner, superresolution microscopy has enabled the imaging of biological structures at resolutions well beyond the diffraction limit. Superresolution optical fluctuation imaging (SOFI) provides an elegant way of overcoming the diffraction limit in all three spatial dimensions by computing higher-order cumulants of image sequences of blinking fluorophores acquired with a conventional widefield microscope. So far, three-dimensional (3D) SOFI has only been demonstrated by sequential imaging of multiple depth positions. Here we introduce a versatile imaging scheme which allows for the simultaneous acquisition of multiple focal planes. Using 3D cross-cumulants, we show that the depth sampling can be increased. Consequently, the simultaneous acquisition of multiple focal planes reduces the acquisition time and hence the photo-bleaching of fluorescent markers. We demonstrate multiplane 3D SOFI by imaging the mitochondria network in fixed ...

  11. Optical and opto-acoustic imaging. (United States)

    Ntziachristos, Vasilis; Razansky, Daniel


     Since the inception of the microscope, optical imaging is serving the biological discovery for more than four centuries. With the recent emergence of methods appropriate for in vivo staining, such as bioluminescence, fluorescent molecular probes, and proteins, as well as nanoparticle-based targeted agents, significant attention has been shifted toward in vivo interrogations of different dynamic biological processes at the molecular level. This progress has been largely supported by the development of advanced optical tomographic imaging technologies suitable for obtaining volumetric visualization of biomarker distributions in small animals at a whole-body or whole-organ scale, an imaging frontier that is not accessible by the existing tissue-sectioning microscopic techniques due to intensive light scattering beyond the depth of a few hundred microns. Biomedical optoacoustics has also emerged in the recent decade as a powerful tool for high-resolution visualization of optical contrast, overcoming a variety of longstanding limitations imposed by light scattering in deep tissues. By detecting tiny sound vibrations, resulting from selective absorption of light at multiple wavelengths, multispectral optoacoustic tomography methods can now "hear color" in three dimensions, i.e., deliver volumetric spectrally enriched (color) images from deep living tissues at high spatial resolution and in real time. These new-found imaging abilities directly relate to preclinical screening applications in animal models and are foreseen to significantly impact clinical decision making as well.

  12. Optical and digital image processing

    CERN Document Server

    Cristobal, Gabriel; Thienpont, Hugo


    In recent years, Moore's law has fostered the steady growth of the field of digital image processing, though the computational complexity remains a problem for most of the digital image processing applications. In parallel, the research domain of optical image processing has matured, potentially bypassing the problems digital approaches were suffering and bringing new applications. The advancement of technology calls for applications and knowledge at the intersection of both areas but there is a clear knowledge gap between the digital signal processing and the optical processing communities. T

  13. Semiconductor Nanocrystals for Biological Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Aihua; Gu, Weiwei; Larabell, Carolyn; Alivisatos, A. Paul


    Conventional organic fluorophores suffer from poor photo stability, narrow absorption spectra and broad emission feature. Semiconductor nanocrystals, on the other hand, are highly photo-stable with broad absorption spectra and narrow size-tunable emission spectra. Recent advances in the synthesis of these materials have resulted in bright, sensitive, extremely photo-stable and biocompatible semiconductor fluorophores. Commercial availability facilitates their application in a variety of unprecedented biological experiments, including multiplexed cellular imaging, long-term in vitro and in vivo labeling, deep tissue structure mapping and single particle investigation of dynamic cellular processes. Semiconductor nanocrystals are one of the first examples of nanotechnology enabling a new class of biomedical applications.

  14. Using electron microscopy to calculate optical properties of biological samples. (United States)

    Wu, Wenli; Radosevich, Andrew J; Eshein, Adam; Nguyen, The-Quyen; Yi, Ji; Cherkezyan, Lusik; Roy, Hemant K; Szleifer, Igal; Backman, Vadim


    The microscopic structural origins of optical properties in biological media are still not fully understood. Better understanding these origins can serve to improve the utility of existing techniques and facilitate the discovery of other novel techniques. We propose a novel analysis technique using electron microscopy (EM) to calculate optical properties of specific biological structures. This method is demonstrated with images of human epithelial colon cell nuclei. The spectrum of anisotropy factor g, the phase function and the shape factor D of the nuclei are calculated. The results show strong agreement with an independent study. This method provides a new way to extract the true phase function of biological samples and provides an independent validation for optical property measurement techniques.

  15. Micro-optics for imaging.

    Energy Technology Data Exchange (ETDEWEB)

    Boye, Robert R.


    This project investigates the fundamental imaging capability of an optic with a physical thickness substantially less than 1 mm. The analysis assumes that post-processing can overcome certain restrictions such as detector pixel size and image degradation due to aberrations. A first order optical analysis quickly reveals the limitations of even an ideal thin lens to provide sufficient image resolution and provides the justification for pursuing an annular design. Some straightforward examples clearly show the potential of this approach. The tradeoffs associated with annular designs, specifically field of view limitations and reduced mid-level spatial frequencies, are discussed and their impact on the imaging performance evaluated using several imaging examples. Additionally, issues such as detector acceptance angle and the need to balance aberrations with resolution are included in the analysis. With these restrictions, the final results present an excellent approximation of the expected performance of the lens designs presented.

  16. Optical cell sorting with multiple imaging modalities

    DEFF Research Database (Denmark)

    Banas, Andrew; Carrissemoux, Caro; Palima, Darwin


    techniques. Scattering forces from beams actuated via efficient phase-only efficient modulation has been adopted. This has lowered the required power for sorting cells to a tenth of our previous approach, and also makes the cell sorter safer for use in clinical settings. With the versatility of dynamically...... programmable phase spatial light modulators, a plurality of light shaping techniques, including hybrid approaches, can be utilized in cell sorting....... healthy cells. With the richness of visual information, a lot of microscopy techniques have been developed and have been crucial in biological studies. To utilize their complementary advantages we adopt both fluorescence and brightfield imaging in our optical cell sorter. Brightfield imaging has...

  17. Application of Quantum Dots in Biological Imaging

    Directory of Open Access Journals (Sweden)

    Shan Jin


    Full Text Available Quantum dots (QDs are a group of semiconducting nanomaterials with unique optical and electronic properties. They have distinct advantages over traditional fluorescent organic dyes in chemical and biological studies in terms of tunable emission spectra, signal brightness, photostability, and so forth. Currently, the major type of QDs is the heavy metal-containing II-IV, IV-VI, or III-V QDs. Silicon QDs and conjugated polymer dots have also been developed in order to lower the potential toxicity of the fluorescent probes for biological applications. Aqueous solubility is the common problem for all types of QDs when they are employed in the biological researches, such as in vitro and in vivo imaging. To circumvent this problem, ligand exchange and polymer coating are proven to be effective, besides synthesizing QDs in aqueous solutions directly. However, toxicity is another big concern especially for in vivo studies. Ligand protection and core/shell structure can partly solve this problem. With the rapid development of QDs research, new elements and new morphologies have been introduced to this area to fabricate more safe and efficient QDs for biological applications.

  18. Fluorescence confocal endomicroscopy in biological imaging (United States)

    Delaney, Peter; Thomas, Steven; Allen, John; McLaren, Wendy; Murr, Elise; Harris, Martin


    In vivo fluorescence microscopic imaging of biological systems in human disease states and animal models is possible with high optical resolution and mega pixel point-scanning performance using optimised off-the-shelf turn-key devices. There are however various trade-offs between tissue access and instrument performance when miniaturising in vivo microscopy systems. A miniature confocal scanning technology that was developed for clinical human endoscopy has been configured into a portable device for direct hand-held interrogation of living tissue in whole animal models (Optiscan FIVE-1 system). Scanning probes of 6.3mm diameter with a distal tip diameter of 5.0mm were constructed either in a 150mm length for accessible tissue, or a 300mm probe for laparoscopic interrogation of internal tissues in larger animal models. Both devices collect fluorescence confocal images (excitation 488 nm; emission >505 or >550 nm) comprised of 1024 x 1204 sampling points/image frame, with lateral resolution 0.7um; axial resolution 7um; FOV 475 x 475um. The operator can dynamically control imaging depth from the tissue surface to approx 250um in 4um steps via an internally integrated zaxis actuator. Further miniaturisation is achieved using an imaging contact probe based on scanning the proximal end of a high-density optical fibre bundle (~30,000 fibres) of sheep and pigs was fluorescently stained with calcein-AM or fluorescein. Surface and sub-surface cellular and sub-cellular details could be readily visualised in vivo at high resolution. In rodent disease models, in vivo endomicroscopy with appropriate fluorescent agents allowed examination of thrombosis formation, tumour microvasculature and liver metastases, diagnosis and staging of ulcerative colitis, liver necrosis and glomerulonephritis. Miniaturised confocal endomicroscopy allows rapid in vivo molecular and subsurface microscopy of normal and pathologic tissue at high resolution in small and large whole animal models

  19. Biomedical Optical Imaging Technologies Design and Applications

    CERN Document Server


    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.

  20. Simulations of optical microscope images (United States)

    Germer, Thomas A.; Marx, Egon


    The resolution of an optical microscope is limited by the optical wavelengths used. However, there is no fundamental limit to the sensitivity of a microscope to small differences in any of a feature's dimensions. That is, those limits are determined by such things as the sensitivity of the detector array, the quality of the optical system, and the stability of the light source. The potential for using this nearly unbounded sensitivity has sparked interest in extending optical microscopy to the characterization of sub-wavelength structures created by photolithography and using that characterization for process control. In this paper, an analysis of the imaging of a semiconductor grating structure with an optical microscope will be presented. The analysis includes the effects of partial coherence in the illumination system, aberrations of both the illumination and the collection optics, non-uniformities in the illumination, and polarization. It can thus model just about any illumination configuration imaginable, including Koehler illumination, focused (confocal) illumination, or dark-field illumination. By propagating Jones matrices throughout the system, polarization control at the back focal planes of both illumination and collection can be investigated. Given a detailed characterization of the microscope (including aberrations), images can be calculated and compared to real data, allowing details of the grating structure to be determined, in a manner similar to that found in scatterometry.

  1. Translational research of optical molecular imaging for personalized medicine. (United States)

    Qin, C; Ma, X; Tian, J


    In the medical imaging field, molecular imaging is a rapidly developing discipline and forms many imaging modalities, providing us effective tools to visualize, characterize, and measure molecular and cellular mechanisms in complex biological processes of living organisms, which can deepen our understanding of biology and accelerate preclinical research including cancer study and medicine discovery. Among many molecular imaging modalities, although the penetration depth of optical imaging and the approved optical probes used for clinics are limited, it has evolved considerably and has seen spectacular advances in basic biomedical research and new drug development. With the completion of human genome sequencing and the emergence of personalized medicine, the specific drug should be matched to not only the right disease but also to the right person, and optical molecular imaging should serve as a strong adjunct to develop personalized medicine by finding the optimal drug based on an individual's proteome and genome. In this process, the computational methodology and imaging system as well as the biomedical application regarding optical molecular imaging will play a crucial role. This review will focus on recent typical translational studies of optical molecular imaging for personalized medicine followed by a concise introduction. Finally, the current challenges and the future development of optical molecular imaging are given according to the understanding of the authors, and the review is then concluded.

  2. Plasmonic optical trapping in biologically relevant media.

    Directory of Open Access Journals (Sweden)

    Brian J Roxworthy

    Full Text Available We present plasmonic optical trapping of micron-sized particles in biologically relevant buffer media with varying ionic strength. The media consist of 3 cell-growth solutions and 2 buffers and are specifically chosen due to their widespread use and applicability to breast-cancer and angiogenesis studies. High-precision rheological measurements on the buffer media reveal that, in all cases excluding the 8.0 pH Stain medium, the fluids exhibit Newtonian behavior, thereby enabling straightforward measurements of optical trap stiffness from power-spectral particle displacement data. Using stiffness as a trapping performance metric, we find that for all media under consideration the plasmonic nanotweezers generate optical forces 3-4x a conventional optical trap. Further, plasmonic trap stiffness values are comparable to those of an identical water-only system, indicating that the performance of a plasmonic nanotweezer is not degraded by the biological media. These results pave the way for future biological applications utilizing plasmonic optical traps.

  3. Optical fibre cantilever sensor for biological application (United States)

    Li, J.; Zhou, Y. X.; Patterson, G.; Shu, W. M.; Maier, R. R. J.; Fowler, R.; Hand, D. P.; MacPherson, W. N.


    Micro-cantilever sensors have shown great promise in a wide range of application are as including chemical and biological sensing. However, many of these devices are based upon a sensor `chip' that requires careful alignment between the cantilever and the read-out system, which can be challenging. Furthermore, optical interrogation typically involves a bulky free-space system. Optical fibre addressed cantilevers have been reported previously in the literature and in this paper we propose techniques to design and fabricate polymer micro-cantilevers for attachment onto the end of standard single mode fibres using laser machining. Low-cost optical sources and a fibre coupled spectrometer are employed to monitor the cantilever deflection and therefore observe biological binding between a species of interest and an activated cantilever. Proof-of-concept experiments show that the sensor is capable of detecting pathogen concentration with down to a level of 105cfu/ml.

  4. Luminescent probes for optical in vivo imaging (United States)

    Texier, Isabelle; Josserand, Veronique; Garanger, Elisabeth; Razkin, Jesus; Jin, Zhaohui; Dumy, Pascal; Favrot, Marie; Boturyn, Didier; Coll, Jean-Luc


    Going along with instrumental development for small animal fluorescence in vivo imaging, we are developing molecular fluorescent probes, especially for tumor targeting. Several criteria have to be taken into account for the optimization of the luminescent label. It should be adapted to the in vivo imaging optical conditions : red-shifted absorption and emission, limited overlap between absorption and emission for a good signal filtering, optimized luminescence quantum yield, limited photo-bleaching. Moreover, the whole probe should fulfill the biological requirements for in vivo labeling : adapted blood-time circulation, biological conditions compatibility, low toxicity. We here demonstrate the ability of the imaging fluorescence set-up developed in LETI to image the bio-distribution of molecular probes on short times after injection. Targeting with Cy5 labeled holo-transferrin of subcutaneous TS/Apc (angiogenic murine breast carcinoma model) or IGROV1 (human ovarian cancer) tumors was achieved. Differences in the kinetics of the protein uptake by the tumors were evidenced. IGROV1 internal metastatic nodes implanted in the peritoneal cavity could be detected in nude mice. However, targeted metastatic nodes in lung cancer could only be imaged after dissection of the mouse. These results validate our fluorescence imaging set-up and the use of Cy5 as a luminescent label. New fluorescent probes based on this dye and a molecular delivery template (the RAFT molecule) can thus be envisioned.

  5. Optical coherence tomography: technology and applications (biological and medical physics, biomedical engineering)

    CERN Document Server


    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.

  6. Natural production of biological optical systems (United States)

    Choi, Seung Ho; Kim, Young L.


    Synthesis and production in nature often provide ideas to design and fabricate advanced biomimetic photonic materials and structures, leading to excellent physical properties and enhanced performance. In addition, the recognition and utilization of natural or biological substances have been typical routes to develop biocompatible and biodegradable materials for medical applications. In this respect, biological lasers utilizing such biomaterials and biostructures have been received considerable attention, given a variety of implications and potentials for bioimaging, biosensing, implantation, and therapy. However, without relying on industrial facilities, eco-friendly massive production of such optical components or systems has not yet been investigated. We show examples of bioproduction of biological lasers using agriculture and fisheries. We anticipate that such approaches will open new possibilities for scalable eco-friendly `green' production of biological photonics components and systems.

  7. Fluorescence imaging spectrometer optical design (United States)

    Taiti, A.; Coppo, P.; Battistelli, E.


    The optical design of the FLuORescence Imaging Spectrometer (FLORIS) studied for the Fluorescence Explorer (FLEX) mission is discussed. FLEX is a candidate for the ESA's 8th Earth Explorer opportunity mission. FLORIS is a pushbroom hyperspectral imager foreseen to be embarked on board of a medium size satellite, flying in tandem with Sentinel-3 in a Sun synchronous orbit at a height of about 815 km. FLORIS will observe the vegetation fluorescence and reflectance within a spectral range between 500 and 780 nm. Multi-frames acquisitions on matrix detectors during the satellite movement will allow the production of 2D Earth scene images in two different spectral channels, called HR and LR with spectral resolution of 0.3 and 2 nm respectively. A common fore optics is foreseen to enhance by design the spatial co-registration between the two spectral channels, which have the same ground spatial sampling (300 m) and swath (150 km). An overlapped spectral range between the two channels is also introduced to simplify the spectral coregistration. A compact opto-mechanical solution with all spherical and plane optical elements is proposed, and the most significant design rationales are described. The instrument optical architecture foresees a dual Babinet scrambler, a dioptric telescope and two grating spectrometers (HR and LR), each consisting of a modified Offner configuration. The developed design is robust, stable vs temperature, easy to align, showing very high optical quality along the whole field of view. The system gives also excellent correction for transverse chromatic aberration and distortions (keystone and smile).

  8. Optical Waveguide Sensing and Imaging

    CERN Document Server

    Bock, Wojtek J; Tanev, Stoyan


    The book explores various aspects of existing and emerging fiber and waveguide optics sensing and imaging technologies including recent advances in nanobiophotonics. The focus is both on fundamental and applied research as well as on applications in civil engineering, biomedical sciences, environment, security and defence. The main goal of the multi-disciplinarry team of Editors was to provide an useful reference of state-of-the-art overviews covering a variety of complementary topics on the interface of engineering and biomedical sciences.

  9. Single cell induced optical confinement in biological lasers (United States)

    Karl, M.; Dietrich, C. P.; Schubert, M.; Samuel, I. D. W.; Turnbull, G. A.; Gather, M. C.


    Biological single cell lasers have shown great potential for fundamental research and next generation sensing applications. In this study, the potential of fluorescent biological cells as refractive index landscapes and active optical elements is investigated using a combined Fourier- and hyperspectral imaging technique. We show that the refractive index contrast between cell and surrounding leads to 3D confinement of photons inside living cells. The Fourier- and real-space emission characteristics of these biological lasers are closely related and can be predicted from one another. Investigations of the lasing threshold for different energy and momentum position in Fourier-space give insight into the fundamental creation of longitudinal and transverse lasing modes within the cell. These findings corroborate the potential of living biological materials for precision engineering of photonic structures and may pave the way towards low threshold polariton lasing from single cells.

  10. Nonlinear plasmonic imaging techniques and their biological applications (United States)

    Deka, Gitanjal; Sun, Chi-Kuang; Fujita, Katsumasa; Chu, Shi-Wei


    Nonlinear optics, when combined with microscopy, is known to provide advantages including novel contrast, deep tissue observation, and minimal invasiveness. In addition, special nonlinearities, such as switch on/off and saturation, can enhance the spatial resolution below the diffraction limit, revolutionizing the field of optical microscopy. These nonlinear imaging techniques are extremely useful for biological studies on various scales from molecules to cells to tissues. Nevertheless, in most cases, nonlinear optical interaction requires strong illumination, typically at least gigawatts per square centimeter intensity. Such strong illumination can cause significant phototoxicity or even photodamage to fragile biological samples. Therefore, it is highly desirable to find mechanisms that allow the reduction of illumination intensity. Surface plasmon, which is the collective oscillation of electrons in metal under light excitation, is capable of significantly enhancing the local field around the metal nanostructures and thus boosting up the efficiency of nonlinear optical interactions of the surrounding materials or of the metal itself. In this mini-review, we discuss the recent progress of plasmonics in nonlinear optical microscopy with a special focus on biological applications. The advancement of nonlinear imaging modalities (including incoherent/coherent Raman scattering, two/three-photon luminescence, and second/third harmonic generations that have been amalgamated with plasmonics), as well as the novel subdiffraction limit imaging techniques based on nonlinear behaviors of plasmonic scattering, is addressed.

  11. Visualization of the Biological Behavior of Tumor-Associated Macrophages in Living Mice with Colon Cancer Using Multimodal Optical Reporter Gene Imaging

    Directory of Open Access Journals (Sweden)

    Yun Ju Choi


    Full Text Available We sought to visualize the migration of tumor-associated macrophages (TAMs to tumor lesions and to evaluate the effects of anti-inflammatory drugs on TAM-modulated tumor progression in mice with colon cancer using a multimodal optical reporter gene system. Murine macrophage Raw264.7 cells expressing an enhanced firefly luciferase (Raw/effluc and murine colon cancer CT26 cells coexpressing Rluc and mCherry (CT26/Rluc-mCherry, CT26/RM were established. CT26/RM tumor-bearing mice received Raw/effluc via their tail veins, and combination of bioluminescence imaging (BLI and fluorescence imaging (FLI was conducted for in vivo imaging of TAMs migration and tumor progression. Dexamethasone (DEX, a potent anti-inflammatory drug, was administered intraperitoneally to tumor-bearing mice following the intravenous transfer of Raw/effluc cells. The migration of TAMs and tumor growth was monitored by serial FLI and BLI. The migration of Raw/effluc cells to tumor lesions was observed at day 1, and BLI signals were still distinct at tumor lesions on day 4. Localization of BLI signals from migrated Raw/effluc cells corresponded to that of FLI signals from CT26/RM tumors. In vivo FLI of tumors demonstrated enhanced tumor growth associated with macrophage migration to tumor lesions. Treatment with DEX inhibited the influx of Raw/effluc cells to tumor lesions and abolished the enhanced tumor growth associated with macrophage migration. These findings suggest that molecular imaging approach for TAM tracking is a valuable tool for evaluating the role of TAMs in the tumor microenvironment as well as for the development of new drugs to control TAM involvement in the modulation of tumor progression.

  12. Use of combined polarization-sensitive optical coherence tomography and Mueller matrix imaging for the polarimetric characterization of excised biological tissue (United States)

    Chue-Sang, Joseph; Bai, Yuqiang; Stoff, Susan; Straton, David; Ramaswamy, Sharan; Ramella-Roman, Jessica C.


    Mueller matrix polarimetry and polarization-sensitive optical coherence tomography (PS-OCT) are two emerging techniques utilized in the assessment of tissue anisotropy. While PS-OCT can provide cross-sectional images of local tissue birefringence through its polarimetric sensitivity, Mueller matrix polarimetry can be used to measure bulk polarimetric properties such as depolarization, diattenuation, and retardance. To this day true quantification of PS-OCT data can be elusive, partly due to the reliance on inverse models for the characterization of tissue birefringence and the influence of instrumentation noise. Similarly for Mueller matrix polarimetry, calculation of retardance or depolarization may be influenced by tissue heterogeneities that could be monitored with PS-OCT. Here, we propose an instrument that combines Mueller matrix polarimetry and PS-OCT. Through the co-registration of the two systems, we aim at achieving a better understanding of both modalities.

  13. Multimodal full-field optical coherence tomography on biological tissue: toward all optical digital pathology (United States)

    Harms, F.; Dalimier, E.; Vermeulen, P.; Fragola, A.; Boccara, A. C.


    Optical Coherence Tomography (OCT) is an efficient technique for in-depth optical biopsy of biological tissues, relying on interferometric selection of ballistic photons. Full-Field Optical Coherence Tomography (FF-OCT) is an alternative approach to Fourier-domain OCT (spectral or swept-source), allowing parallel acquisition of en-face optical sections. Using medium numerical aperture objective, it is possible to reach an isotropic resolution of about 1x1x1 ìm. After stitching a grid of acquired images, FF-OCT gives access to the architecture of the tissue, for both macroscopic and microscopic structures, in a non-invasive process, which makes the technique particularly suitable for applications in pathology. Here we report a multimodal approach to FF-OCT, combining two Full-Field techniques for collecting a backscattered endogeneous OCT image and a fluorescence exogeneous image in parallel. Considering pathological diagnosis of cancer, visualization of cell nuclei is of paramount importance. OCT images, even for the highest resolution, usually fail to identify individual nuclei due to the nature of the optical contrast used. We have built a multimodal optical microscope based on the combination of FF-OCT and Structured Illumination Microscopy (SIM). We used x30 immersion objectives, with a numerical aperture of 1.05, allowing for sub-micron transverse resolution. Fluorescent staining of nuclei was obtained using specific fluorescent dyes such as acridine orange. We present multimodal images of healthy and pathological skin tissue at various scales. This instrumental development paves the way for improvements of standard pathology procedures, as a faster, non sacrificial, operator independent digital optical method compared to frozen sections.

  14. Image processing and computing in structural biology

    NARCIS (Netherlands)

    Jiang, Linhua


    With the help of modern techniques of imaging processing and computing, image data obtained by electron cryo-microscopy of biomolecules can be reconstructed to three-dimensional biological models at sub-nanometer resolution. These models allow answering urgent problems in life science, for instance,

  15. A Biologically Inspired CMOS Image Sensor

    CERN Document Server

    Sarkar, Mukul


    Biological systems are a source of inspiration in the development of small autonomous sensor nodes. The two major types of optical vision systems found in nature are the single aperture human eye and the compound eye of insects. The latter are among the most compact and smallest vision sensors. The eye is a compound of individual lenses with their own photoreceptor arrays.  The visual system of insects allows them to fly with a limited intelligence and brain processing power. A CMOS image sensor replicating the perception of vision in insects is discussed and designed in this book for industrial (machine vision) and medical applications. The CMOS metal layer is used to create an embedded micro-polarizer able to sense polarization information. This polarization information is shown to be useful in applications like real time material classification and autonomous agent navigation. Further the sensor is equipped with in pixel analog and digital memories which allow variation of the dynamic range and in-pixel b...

  16. Integrated structural and functional optical imaging combining spectral-domain optical coherence and multiphoton microscopy

    CERN Document Server

    Vinegoni, C; Luo, W; Marks, D L; Ralston, T; Tan, W


    An integrated microscope that combines different optical techniques for simultaneous imaging is demonstrated. The microscope enables spectral-domain optical coherence microscopy based on optical backscatter, and multi-photon microscopy for the detection of two-photon fluorescence and second harmonic generation signals. The unique configuration of this integrated microscope allows for the simultaneous acquisition of both anatomical (structural) and functional imaging information with particular emphasis for applications in the fields of tissue engineering and cell biology. In addition, the contemporary analysis of the spectroscopic features can enhance contrast by differentiating among different tissue components.

  17. A Biologically Inspired CMOS Image Sensor

    NARCIS (Netherlands)

    Sarkar, M.


    Biological systems are a source of inspiration in the development of small autonomous sensor nodes. The two major types of optical vision systems found in nature are the single aperture human eye and the compound eye of insects. The latter are among the most compact and smallest vision sensors. The

  18. Coherence-Gated Sensorless Adaptive Optics Multiphoton Retinal Imaging (United States)

    Cua, Michelle; Wahl, Daniel J.; Zhao, Yuan; Lee, Sujin; Bonora, Stefano; Zawadzki, Robert J.; Jian, Yifan; Sarunic, Marinko V.


    Multiphoton microscopy enables imaging deep into scattering tissues. The efficient generation of non-linear optical effects is related to both the pulse duration (typically on the order of femtoseconds) and the size of the focused spot. Aberrations introduced by refractive index inhomogeneity in the sample distort the wavefront and enlarge the focal spot, which reduces the multiphoton signal. Traditional approaches to adaptive optics wavefront correction are not effective in thick or multi-layered scattering media. In this report, we present sensorless adaptive optics (SAO) using low-coherence interferometric detection of the excitation light for depth-resolved aberration correction of two-photon excited fluorescence (TPEF) in biological tissue. We demonstrate coherence-gated SAO TPEF using a transmissive multi-actuator adaptive lens for in vivo imaging in a mouse retina. This configuration has significant potential for reducing the laser power required for adaptive optics multiphoton imaging, and for facilitating integration with existing systems.

  19. Coherence-Gated Sensorless Adaptive Optics Multiphoton Retinal Imaging. (United States)

    Cua, Michelle; Wahl, Daniel J; Zhao, Yuan; Lee, Sujin; Bonora, Stefano; Zawadzki, Robert J; Jian, Yifan; Sarunic, Marinko V


    Multiphoton microscopy enables imaging deep into scattering tissues. The efficient generation of non-linear optical effects is related to both the pulse duration (typically on the order of femtoseconds) and the size of the focused spot. Aberrations introduced by refractive index inhomogeneity in the sample distort the wavefront and enlarge the focal spot, which reduces the multiphoton signal. Traditional approaches to adaptive optics wavefront correction are not effective in thick or multi-layered scattering media. In this report, we present sensorless adaptive optics (SAO) using low-coherence interferometric detection of the excitation light for depth-resolved aberration correction of two-photon excited fluorescence (TPEF) in biological tissue. We demonstrate coherence-gated SAO TPEF using a transmissive multi-actuator adaptive lens for in vivo imaging in a mouse retina. This configuration has significant potential for reducing the laser power required for adaptive optics multiphoton imaging, and for facilitating integration with existing systems.

  20. Optical Coherence Tomography for Brain Imaging (United States)

    Liu, Gangjun; Chen, Zhongping

    Recently, there has been growing interest in using OCT for brain imaging. A feasibility study of OCT for guiding deep brain probes has found that OCT can differentiate the white matter and gray matter because the white matter tends to have a higher peak reflectivity and steeper attenuation rate compared to gray matter. In vivo 3D visualization of the layered organization of a rat olfactory bulb with OCT has been demonstrated. OCT has been used for single myelin fiber imaging in living rodents without labeling. The refractive index in the rat somatosensory cortex has also been measured with OCT. In addition, functional extension of OCT, such as Doppler-OCT (D-OCT), polarization sensitive-OCT (PS-OCT), and phase-resolved-OCT (PR-OCT), can image and quantify physiological parameters in addition to the morphological structure image. Based on the scattering changes during neural activity, OCT has been used to measure the functional activation in neuronal tissues. PS-OCT, which combines polarization sensitive detection with OCT to determine tissue birefringence, has been used for the localization of nerve fiber bundles and the mapping of micrometer-scale fiber pathways in the brain. D-OCT, also named optical Doppler tomography (ODT), combines the Doppler principle with OCT to obtain high resolution tomographic images of moving constituents in highly scattering biological tissues. D-OCT has been successfully used to image cortical blood flow and map the blood vessel network for brain research. In this chapter, the principle and technology of OCT and D-OCT are reviewed and examples of potential applications are described.

  1. Imaging granulomatous lesions with optical coherence tomography

    DEFF Research Database (Denmark)

    Banzhaf, Christina; Jemec, Gregor B E


    To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors.......To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT) images and compare this to previous studies of nonmelanoma skin tumors....

  2. Imaging cellular and molecular biological functions

    Energy Technology Data Exchange (ETDEWEB)

    Shorte, S.L. [Institut Pasteur, 75 - Paris (France). Plateforme d' Imagerie Dynamique PFID-Imagopole; Frischknecht, F. (eds.) [Heidelberg Univ. Medical School (Germany). Dept. of Parasitology


    'Imaging cellular and molecular biological function' provides a unique selection of essays by leading experts, aiming at scientist and student alike who are interested in all aspects of modern imaging, from its application and up-scaling to its development. Indeed the philosophy of this volume is to provide student, researcher, PI, professional or provost the means to enter this applications field with confidence, and to construct the means to answer their own specific questions. (orig.)

  3. microlith : Image Simulation for Biological Phase Microscopy

    CERN Document Server

    Mehta, Shalin B


    Accurate simulation of image formation remains under-exploited for biological phase microscopy methods that employ partially coherent illumination, despite being important for the design of imaging systems and the reconstruction algorithms. We present an open-source MATLAB toolbox, microlith (, that provides accurate simulation of the 3D image of a thin specimen under any partially coherent imaging system, including coherent or incoherent systems. We demonstrate the accuracy of the microlith toolbox by comparing simulated images and experimental images of a phase-only Siemens star test target using dark field and differential interference contrast microscopes. The comparison leads to intriguing insights about the sensitivity of the dark-field microscope to sub-resolution features and effects of specimen birefringence on differential interference contrast.

  4. Fluorescent quantum dots: synthesis, biomedical optical imaging, and biosafety assessment. (United States)

    Ji, Xiaoyuan; Peng, Fei; Zhong, Yiling; Su, Yuanyuan; He, Yao


    The marriage of nanomaterials with biology has significantly promoted advancement of biological techniques, profoundly facilitating basic research and practical applications in biological and biomedical fields. Taking advantages of unique optical properties (e.g., strong fluorescence, robust photostability, size-tunable emission wavelengths, etc.), fluorescent quantum dots (QDs), appearing as high-performance biological fluorescent nanoprobes, have been extensively explored for a variety of biomedical optical imaging applications. In this review, we present representative synthetic strategies for preparation of QDs and their applications in biomedical optical imaging, as well as risk assessments in vitro and in vivo. Briefly, we first summarize recent progress in fabrication of QDs via two rudimentary approaches, i.e., organometallic route and aqueous synthesis. Next we present representative achievement in QDs-based in vitro and in vivo biomedical optical imaging applications. We further discuss the toxicity assessment of QDs, ranging from cell studies to animal models. In the final section, we discuss challenges and perspectives for the QDs-relative bioapplications in the future.

  5. AFM Imaging of Natural Optical Structures

    Directory of Open Access Journals (Sweden)

    Dinara Sultanovna Dallaeva


    Full Text Available The research in this field is focused to the investigation of biological structures with superior optical features. The study presents atomic force microscopy of biological optical structures on butterfly wings. The bright blue and dark black color scales exhibit the different topography. These scales were compared to the visually the same color scales of other two species of butterflies. The histograms of heights distribution are presented and show similar results for the scales of one color for different species.

  6. Nonlinear spectral imaging of biological tissues

    NARCIS (Netherlands)

    Palero, J.A.


    The work presented in this thesis demonstrates live high resolution 3D imaging of tissue in its native state and environment. The nonlinear interaction between focussed femtosecond light pulses and the biological tissue results in the emission of natural autofluorescence and second-harmonic signal.

  7. Functional imaging of small tissue volumes with diffuse optical tomography (United States)

    Klose, Alexander D.; Hielscher, Andreas H.


    Imaging of dynamic changes in blood parameters, functional brain imaging, and tumor imaging are the most advanced application areas of diffuse optical tomography (DOT). When dealing with the image reconstruction problem one is faced with the fact that near-infrared photons, unlike X-rays, are highly scattered when they traverse biological tissue. Image reconstruction schemes are required that model the light propagation inside biological tissue and predict measurements on the tissue surface. By iteratively changing the tissue-parameters until the predictions agree with the real measurements, a spatial distribution of optical properties inside the tissue is found. The optical properties can be related to the tissue oxygenation, inflammation, or to the fluorophore concentration of a biochemical marker. If the model of light propagation is inaccurate, the reconstruction process will lead to an inaccurate result as well. Here, we focus on difficulties that are encountered when DOT is employed for functional imaging of small tissue volumes, for example, in cancer studies involving small animals, or human finger joints for early diagnosis of rheumatoid arthritis. Most of the currently employed image reconstruction methods rely on the diffusion theory that is an approximation to the equation of radiative transfer. But, in the cases of small tissue volumes and tissues that contain low scattering regions diffusion theory has been shown to be of limited applicability Therefore, we employ a light propagation model that is based on the equation of radiative transfer, which promises to overcome the limitations.

  8. Optics for Advanced Neutron Imaging and Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Moncton, David E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Khaykovich, Boris [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)


    During the report period, we continued the work as outlined in the original proposal. We have analyzed potential optical designs of Wolter mirrors for the neutron-imaging instrument VENUS, which is under construction at SNS. In parallel, we have conducted the initial polarized imaging experiment at Helmholtz Zentrum, Berlin, one of very few of currently available polarized-imaging facilities worldwide.

  9. Optical Fourier techniques for medical image processing and phase contrast imaging. (United States)

    Yelleswarapu, Chandra S; Kothapalli, Sri-Rajasekhar; Rao, D V G L N


    This paper briefly reviews the basics of optical Fourier techniques (OFT) and applications for medical image processing as well as phase contrast imaging of live biological specimens. Enhancement of microcalcifications in a mammogram for early diagnosis of breast cancer is the main focus. Various spatial filtering techniques such as conventional 4f filtering using a spatial mask, photoinduced polarization rotation in photosensitive materials, Fourier holography, and nonlinear transmission characteristics of optical materials are discussed for processing mammograms. We also reviewed how the intensity dependent refractive index can be exploited as a phase filter for phase contrast imaging with a coherent source. This novel approach represents a significant advance in phase contrast microscopy.

  10. NAOMI: nanoparticle-assisted optical molecular imaging (United States)

    Faber, Dirk J.; de Bruin, Martijn; Aalders, Maurice C. G.; Verbraak, Frank D.; van Leeuwen, Ton G.


    We present our first steps towards nanoparticle assisted, optical molecular imaging (NAOMI) using biodegradable nanoparticles. Our focus is on using optical coherence tomography(OCT) as the imaging modality. We propose to use nanoparticles based on biodegradable polymers, loaded with carefully selected dyes as contrast agent, and outline a method for establishing their desired optical properties prior to synthesis. Moreover, we perform a qualitative pilot study using these biodegradable nanoparticles, measuring their optical properties which are found to be in line with theoretical predictions.

  11. Radio-Optical Imaging of ATLBS Survey

    Indian Academy of Sciences (India)

    Kshitij Thorat


    We present the radio-optical imaging of ATLBS, a sensitive radio survey (Subrahmanyan et al. 2010). The primary aim of the ATLBS survey is to image low-power radio sources which form the bulk of the radio source population to moderately high red-shifts ( ∼ 1.0). The accompanying multiband optical and near infra-red observations provide information about the hosts and environments of the radio sources. We give here details of the imaging of the radio data and optical data for the ATLBS survey.

  12. Optical Imaging Sensors and Systems for Homeland Security Applications

    CERN Document Server

    Javidi, Bahram


    Optical and photonic systems and devices have significant potential for homeland security. Optical Imaging Sensors and Systems for Homeland Security Applications presents original and significant technical contributions from leaders of industry, government, and academia in the field of optical and photonic sensors, systems and devices for detection, identification, prevention, sensing, security, verification and anti-counterfeiting. The chapters have recent and technically significant results, ample illustrations, figures, and key references. This book is intended for engineers and scientists in the relevant fields, graduate students, industry managers, university professors, government managers, and policy makers. Advanced Sciences and Technologies for Security Applications focuses on research monographs in the areas of -Recognition and identification (including optical imaging, biometrics, authentication, verification, and smart surveillance systems) -Biological and chemical threat detection (including bios...

  13. Gated frequency-resolved optical imaging with an optical parametric amplifier for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, S.M.; Bliss, D.E.


    Implementation of optical imagery in a diffuse inhomogeneous medium such as biological tissue requires an understanding of photon migration and multiple scattering processes which act to randomize pathlength and degrade image quality. The nature of transmitted light from soft tissue ranges from the quasi-coherent properties of the minimally scattered component to the random incoherent light of the diffuse component. Recent experimental approaches have emphasized dynamic path-sensitive imaging measurements with either ultrashort laser pulses (ballistic photons) or amplitude modulated laser light launched into tissue (photon density waves) to increase image resolution and transmissive penetration depth. Ballistic imaging seeks to compensate for these {open_quotes}fog-like{close_quotes} effects by temporally isolating the weak early-arriving image-bearing component from the diffusely scattered background using a subpicosecond optical gate superimposed on the transmitted photon time-of-flight distribution. The authors have developed a broadly wavelength tunable (470 nm -2.4 {mu}m), ultrashort amplifying optical gate for transillumination spectral imaging based on optical parametric amplification in a nonlinear crystal. The time-gated image amplification process exhibits low noise and high sensitivity, with gains greater than 104 achievable for low light levels. We report preliminary benchmark experiments in which this system was used to reconstruct, spectrally upcovert, and enhance near-infrared two-dimensional images with feature sizes of 65 {mu}m/mm{sup 2} in background optical attenuations exceeding 10{sup 12}. Phase images of test objects exhibiting both absorptive contrast and diffuse scatter were acquired using a self-referencing Shack-Hartmann wavefront sensor in combination with short-pulse quasi-ballistic gating. The sensor employed a lenslet array based on binary optics technology and was sensitive to optical path distortions approaching {lambda}/100.

  14. Space-based optical image encryption. (United States)

    Chen, Wen; Chen, Xudong


    In this paper, we propose a new method based on a three-dimensional (3D) space-based strategy for the optical image encryption. The two-dimensional (2D) processing of a plaintext in the conventional optical encryption methods is extended to a 3D space-based processing. Each pixel of the plaintext is considered as one particle in the proposed space-based optical image encryption, and the diffraction of all particles forms an object wave in the phase-shifting digital holography. The effectiveness and advantages of the proposed method are demonstrated by numerical results. The proposed method can provide a new optical encryption strategy instead of the conventional 2D processing, and may open up a new research perspective for the optical image encryption.

  15. Magnetic resonance imaging of optic nerve

    Directory of Open Access Journals (Sweden)

    Foram Gala


    Full Text Available Optic nerves are the second pair of cranial nerves and are unique as they represent an extension of the central nervous system. Apart from clinical and ophthalmoscopic evaluation, imaging, especially magnetic resonance imaging (MRI, plays an important role in the complete evaluation of optic nerve and the entire visual pathway. In this pictorial essay, the authors describe segmental anatomy of the optic nerve and review the imaging findings of various conditions affecting the optic nerves. MRI allows excellent depiction of the intricate anatomy of optic nerves due to its excellent soft tissue contrast without exposure to ionizing radiation, better delineation of the entire visual pathway, and accurate evaluation of associated intracranial pathologies.

  16. Adaptive optics optical coherence tomography for retina imaging

    Institute of Scientific and Technical Information of China (English)

    Guohua Shi; Yun Dai; Ling Wang; Zhihua Ding; Xuejun Rao; Yudong Zhang


    When optical coherence tomography (OCT) is used for human retina imaging, its transverse resolution is limited by the aberrations of human eyes. To overcome this disadvantage, a high resolution imaging system for living human retina, which consists of a time domain OCT system and a 37-elements adaptive optics (AO) system, has been developed. The AO closed loop rate is 20 frames per second, and the OCT has a 6.7-μm axial resolution. In this paper, this system is introduced and the high resolution imaging results for retina are presented.

  17. Optical image encryption using multilevel Arnold transform and noninterferometric imaging (United States)

    Chen, Wen; Chen, Xudong


    Information security has attracted much current attention due to the rapid development of modern technologies, such as computer and internet. We propose a novel method for optical image encryption using multilevel Arnold transform and rotatable-phase-mask noninterferometric imaging. An optical image encryption scheme is developed in the gyrator transform domain, and one phase-only mask (i.e., phase grating) is rotated and updated during image encryption. For the decryption, an iterative retrieval algorithm is proposed to extract high-quality plaintexts. Conventional encoding methods (such as digital holography) have been proven vulnerably to the attacks, and the proposed optical encoding scheme can effectively eliminate security deficiency and significantly enhance cryptosystem security. The proposed strategy based on the rotatable phase-only mask can provide a new alternative for data/image encryption in the noninterferometric imaging.

  18. Adaptive optics imaging of the retina. (United States)

    Battu, Rajani; Dabir, Supriya; Khanna, Anjani; Kumar, Anupama Kiran; Roy, Abhijit Sinha


    Adaptive optics is a relatively new tool that is available to ophthalmologists for study of cellular level details. In addition to the axial resolution provided by the spectral-domain optical coherence tomography, adaptive optics provides an excellent lateral resolution, enabling visualization of the photoreceptors, blood vessels and details of the optic nerve head. We attempt a mini review of the current role of adaptive optics in retinal imaging. PubMed search was performed with key words Adaptive optics OR Retina OR Retinal imaging. Conference abstracts were searched from the Association for Research in Vision and Ophthalmology (ARVO) and American Academy of Ophthalmology (AAO) meetings. In total, 261 relevant publications and 389 conference abstracts were identified.

  19. Adaptive optics imaging of the retina

    Directory of Open Access Journals (Sweden)

    Rajani Battu


    Full Text Available Adaptive optics is a relatively new tool that is available to ophthalmologists for study of cellular level details. In addition to the axial resolution provided by the spectral-domain optical coherence tomography, adaptive optics provides an excellent lateral resolution, enabling visualization of the photoreceptors, blood vessels and details of the optic nerve head. We attempt a mini review of the current role of adaptive optics in retinal imaging. PubMed search was performed with key words Adaptive optics OR Retina OR Retinal imaging. Conference abstracts were searched from the Association for Research in Vision and Ophthalmology (ARVO and American Academy of Ophthalmology (AAO meetings. In total, 261 relevant publications and 389 conference abstracts were identified.

  20. Advanced Imaging Optics Utilizing Wavefront Coding.

    Energy Technology Data Exchange (ETDEWEB)

    Scrymgeour, David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Boye, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Adelsberger, Kathleen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    Image processing offers a potential to simplify an optical system by shifting some of the imaging burden from lenses to the more cost effective electronics. Wavefront coding using a cubic phase plate combined with image processing can extend the system's depth of focus, reducing many of the focus-related aberrations as well as material related chromatic aberrations. However, the optimal design process and physical limitations of wavefront coding systems with respect to first-order optical parameters and noise are not well documented. We examined image quality of simulated and experimental wavefront coded images before and after reconstruction in the presence of noise. Challenges in the implementation of cubic phase in an optical system are discussed. In particular, we found that limitations must be placed on system noise, aperture, field of view and bandwidth to develop a robust wavefront coded system.

  1. Small Animal Radionuclide Imaging With Focusing Gamma-Ray Optics

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R; Decker, T; Epstein, M; Ziock, K; Pivovaroff, M J; Craig, W W; Jernigan, J G; Barber, W B; Christensen, F E; Funk, T; Hailey, C J; Hasegawa, B H; Taylor, C


    Significant effort currently is being devoted to the development of noninvasive imaging systems that allow in vivo assessment of biological and biomolecular interactions in mice and other small animals. While physiological function in small animals can be localized and imaged using conventional radionuclide imaging techniques such as single-photon emission tomography (SPECT) and positron emission tomography (PET), these techniques inherently are limited to spatial resolutions of 1-2 mm. For this reason, we are developing a small animal radionuclide imaging system (SARIS) using grazing incidence optics to focus gamma-rays emitted by {sup 125}I and other radiopharmaceuticals. We have developed a prototype optic with sufficient accuracy and precision to focus the 27.5 keV photons from {sup 125}I onto a high-resolution imaging detector. Experimental measurements from the prototype have demonstrated that the optic can focus X-rays from a microfocus X-ray tube to a spot having physical dimensions (approximately 1500 microns half-power diameter) consistent with those predicted by theory. Our theoretical and numerical analysis also indicate that an optic can be designed and build that ultimately can achieve 100 {micro}m spatial resolution with sufficient efficiency to perform in vivo single photon emission imaging studies in small animal.

  2. Synergizing superresolution optical fluctuation imaging with single molecule localization microscopy

    CERN Document Server

    Schidorsky, Shachar; Razvag, Yair; Golan, Yonatan; Weiss, Shimon; Sherman, Eilon


    Single molecule localization microscopy (SMLM) techniques enable imaging biological samples well beyond the diffraction limit of light, but they vary significantly in their spatial and temporal resolutions. High-order statistical analysis of temporal fluctuations as in superresolution optical fluctuation imaging (SOFI) also enable imaging beyond diffraction limit, but usually at a lower resolution as compared to SMLM. Since the same data format is acquired for both methods, their algorithms can be applied to the same data set, and thus may be combined synergistically to improve overall imaging performance. Here, we find that SOFI converges much faster than SMLM, provides additive information to SMLM, and can efficiently reject background. We then show how SOFI-assisted SMLM imaging can improve SMLM image reconstruction by rejecting common sources of background, especially under low signal-to-background conditions. The performance of our approach was evaluated using a realistic simulation of fluorescence imagi...

  3. Optical medical imaging: from glass to man (United States)

    Bradley, Mark


    A formidable challenge in modern respiratory healthcare is the accurate and timely diagnosis of lung infection and inflammation. The EPSRC Interdisciplinary Research Collaboration (IRC) `Proteus' seeks to address this challenge by developing an optical fibre based healthcare technology platform that combines physiological sensing with multiplexed optical molecular imaging. This technology will enable in situ measurements deep in the human lung allowing the assessment of tissue function and characterization of the unique signatures of pulmonary disease and is illustrated here with our in-man application of Optical Imaging SmartProbes and our first device Versicolour.

  4. Optically controlled collisions of biological objects (United States)

    Davies, Benjamin J.; Kishore, Rani; Mammen, Mathai; Helmerson, Kristian; Choi, Seok-Ki; Phillips, William D.; Whitesides, George M.


    We have developed a new assay in which two mesoscale particles are caused to collide using two independently controlled optical tweezers. This assay involves the measurement of the adhesion probability following a collision. Since the relative orientation, impact parameter (i.e., distance of closest approach), and collision velocity of the particles, as well as the components of the solution, are all under the user's control, this assay can mimic a wide range of biologically relevant collisions. We illustrate the utility of our assay by evaluating the adhesion probability of a single erythrocyte (red blood cell) to an influenza virus-coated microsphere, in the presence of sialic acid-bearing inhibitors of adhesion. This probability as a function of inhibitor concentration yields a measure of the effectiveness of the inhibitor for blocking viral adhesion. Most of the inhibition constants obtained using the tweezers agree well with those obtained from other techniques, although the inhibition constants for the best of the inhibitors were beyond the limited resolution of conventional assays. They were readily evaluated using our tweezers-based assay, however, and prove to be the most potent inhibitors of adhesion between influenza virus and erythrocytes ever measured. Further studies are underway to investigate the effect of collision velocity on the adhesion probability, with the eventual goal of understanding the various mechanisms of inhibition (direct competition for viral binding sites versus steric stabilization). Analysis of these data also provide evidence that the density of binding sites may be a crucial parameter in the application of this assay and polymeric inhibition in general.

  5. Evaluation of tissue optical properties from light distribution images (United States)

    Tsai, Cheng-Lun; Chang, Ming; Hsieh, Jui-Hsiang; Yang, Yi-Fong; Chou, Yi-Sheong


    Images of light distribution in biological soft tissue we used to study the optical characteristics of tissue. The light distribution image was taken under a microscope with light injected through a pinhole close to the edge of the top surface. Images taken on skin, fat, and muscle tissues were compared to study the effect of cellular structure and temperature on the light intensity distribution. Monte Carlo simulation with the same conditions was also performed to simulate the light intensity distribution in tissue for comparison. The anisotropy scattering of light in tissue is affected by the tissue microscopic structure, such as the direction of muscle tissue fibers. The change in optical properties of fat and muscle tissue with temperature was observed. The two-dimensional light distribution images offer more information than general reflectance and transmission measurements. By matching the simulated light intensity distribution with the light distribution image, the optical properties of biological tissue could be estimated. This method might be applied in tissue engineering as an economic way for evaluating the microscopic structure of tissue.

  6. Optical encryption with selective computational ghost imaging (United States)

    Zafari, Mohammad; kheradmand, Reza; Ahmadi-Kandjani, Sohrab


    Selective computational ghost imaging (SCGI) is a technique which enables the reconstruction of an N-pixel image from N measurements or less. In this paper we propose an optical encryption method based on SCGI and experimentally demonstrate that this method has much higher security under eavesdropping and unauthorized accesses compared with previous reported methods.

  7. Optical imaging of fast, dynamic neurophysiological function.

    Energy Technology Data Exchange (ETDEWEB)

    Rector, D. M. (David M.); Carter, K. M. (Kathleen M.); Yao, X. (Xincheng); George, J. S. (John S.)


    Fast evoked responses were imaged from rat dorsal medulla and whisker barrel cortex. To investigate the biophysical mechanisms involved, fast optical responses associated with isolated crustacean nerve stimulation were recorded using birefringence and scattered light. Such studies allow optimization of non-invasive imaging techniques being developed for use in humans.

  8. Combining calcium imaging with other optical techniques. (United States)

    Canepari, Marco; Zecevic, Dejan; Vogt, Kaspar E; Ogden, David; De Waard, Michel


    Ca(2+) imaging is a commonly used approach for measuring Ca(2+) signals at high spatial resolution. The method is often combined with electrode recordings to correlate electrical and chemical signals or to investigate Ca(2+) signals following an electrical stimulation. To obtain information on electrical activity at the same spatial resolution, Ca(2+) imaging must be combined with membrane potential imaging. Similarly, stimulation of subcellular compartments requires photostimulation. Thus, combining Ca(2+) imaging with an additional optical technique facilitates the study of a number of physiological questions. The aim of this article is to introduce some basic principles regarding the combination of Ca(2+) imaging with other optical techniques. We discuss the design of the optics, the design of experimental protocols, the optical characteristics of Ca(2+) indicators used in combination with an optical probe, and the affinity of the Ca(2+) indicator in relation to the type of measurement. This information will enable the reader to devise an optimal strategy for combined optical experiments.

  9. Optical Digital Image Storage System (United States)


    This could be accomplished even if the files were artificially determined. " Super files," composed of a number of files, could be artificially order to expedite transfer through the scanning process. These " super files" could later be broken down into their actual component files. Another...hesitant about implementing an optical disk system. While Sandra Napier believed it "looks promising," she felt an optical disk replacement of microfilm

  10. Imaging morphogenesis: technological advances and biological insights. (United States)

    Keller, Philipp J


    Morphogenesis, the development of the shape of an organism, is a dynamic process on a multitude of scales, from fast subcellular rearrangements and cell movements to slow structural changes at the whole-organism level. Live-imaging approaches based on light microscopy reveal the intricate dynamics of this process and are thus indispensable for investigating the underlying mechanisms. This Review discusses emerging imaging techniques that can record morphogenesis at temporal scales from seconds to days and at spatial scales from hundreds of nanometers to several millimeters. To unlock their full potential, these methods need to be matched with new computational approaches and physical models that help convert highly complex image data sets into biological insights.

  11. Image correction in magneto-optical microscopy

    DEFF Research Database (Denmark)

    Paturi, P.; Larsen, B.H.; Jacobsen, B.A.


    An image-processing procedure that assures correct determination of the magnetic field distribution of magneto-optical images is presented. The method remedies image faults resulting from sources that are proportional to the incident light intensity, such as different types of defects in the indi......An image-processing procedure that assures correct determination of the magnetic field distribution of magneto-optical images is presented. The method remedies image faults resulting from sources that are proportional to the incident light intensity, such as different types of defects...... in the indicator film and unevenness of light, as well as additive signals from detector bias, external light sources, etc. When properly corrected a better measurement of the local magnetic field can be made, even in the case of heavily damaged films. For superconductors the magnetic field distributions may...

  12. Molecular Imaging in Synthetic Biology, and Synthetic Biology in Molecular Imaging. (United States)

    Gilad, Assaf A; Shapiro, Mikhail G


    Biomedical synthetic biology is an emerging field in which cells are engineered at the genetic level to carry out novel functions with relevance to biomedical and industrial applications. This approach promises new treatments, imaging tools, and diagnostics for diseases ranging from gastrointestinal inflammatory syndromes to cancer, diabetes, and neurodegeneration. As these cellular technologies undergo pre-clinical and clinical development, it is becoming essential to monitor their location and function in vivo, necessitating appropriate molecular imaging strategies, and therefore, we have created an interest group within the World Molecular Imaging Society focusing on synthetic biology and reporter gene technologies. Here, we highlight recent advances in biomedical synthetic biology, including bacterial therapy, immunotherapy, and regenerative medicine. We then discuss emerging molecular imaging approaches to facilitate in vivo applications, focusing on reporter genes for noninvasive modalities such as magnetic resonance, ultrasound, photoacoustic imaging, bioluminescence, and radionuclear imaging. Because reporter genes can be incorporated directly into engineered genetic circuits, they are particularly well suited to imaging synthetic biological constructs, and developing them provides opportunities for creative molecular and genetic engineering.

  13. NAOMI: nanoparticle assisted optical molecular imaging (United States)

    Faber, Dirk J.; van Velthoven, Mirjam E. J.; de Bruin, Martijn; Aalders, Maurice C. G.; Verbraak, Frank D.; Graf, Christina; van Leeuwen, Ton G.


    Our first steps towards nanoparticle assisted, optical molecular imaging (NAOMI) using OCT as the imaging modality are presented. We derive an expression to estimate the sensitivity of this technique. We propose to use nanoparticles based on biodegradable polymers, loaded with suitable dyes as contrast agent, and outline a method for establishing their desired optical properties prior to synthesis. This report presents preliminary results of our investigation on the use of nanoshells to serve as contrast agents We injected nanoshells with specific contrast features in the 800 nm wavelength region in excised porcine eyes. The nanoshells showed up as bright reflecting structures in the OCT images, which confirm their potential as contrast agents.

  14. Optical characterization of biological tissues and rare earth nanoparticles (United States)

    Barrera, Frederick John, III

    The ubiquitous use of lasers as both a diagnostic and therapeutic tool for medical applications (e.g. laser surgery, photoacoustic imaging, photodynamic therapy etc.), had rendered the understanding of optical properties of a biological medium critically important. The development of biomedical devices for the purposes of imaging or treatment requires a detailed investigation of these properties. Indeed, diagnostic monitoring of blood in vivo depends on knowledge of the distribution of light due to scattering in a blood medium. In addition, many optical properties of tissues have not been investigated experimentally at many clinically relevant wavelengths. The quantification of the scattering and absorptive behavior of tissue and its interaction with electromagnetic radiation is still at the core of predicting the outcome of a desired clinical effect. Therefore, the first portion of this Dissertation is a thorough characterization of ocular tissues in vitro using reflectance and transmittance spectroscopic techniques and computational models to extract and enlist a systematic study at wavelengths in the visible spectral region. The Kubelka-Munk (KM), Inverse Adding Doubling (IAD), and Inverse Monte Carlo (IMC) methods were used to determine the absorption and scattering coefficients and contrasted. The second portion of this Dissertation is an investigation of the optical and spectroscopic properties of novel rare earth Y2O3 and Nd3+:Y2O 3nanoparticles in a blood medium. Reflectance and transmittance measurements were performed and the absorption and scattering properties for the nanoparticle/blood samples were determined by computational methods and compared. Absorption and emission of Y2O3 and Nd3+:Y 2O3nanoparticle/blood medium revealed their utility as biomarkers.

  15. Exploring lipids with nonlinear optical microscopy in multiple biological systems (United States)

    Alfonso-Garcia, Alba

    Lipids are crucial biomolecules for the well being of humans. Altered lipid metabolism may give rise to a variety of diseases that affect organs from the cardiovascular to the central nervous system. A deeper understanding of lipid metabolic processes would spur medical research towards developing precise diagnostic tools, treatment methods, and preventive strategies for reducing the impact of lipid diseases. Lipid visualization remains a complex task because of the perturbative effect exerted by traditional biochemical assays and most fluorescence markers. Coherent Raman scattering (CRS) microscopy enables interrogation of biological samples with minimum disturbance, and is particularly well suited for label-free visualization of lipids, providing chemical specificity without compromising on spatial resolution. Hyperspectral imaging yields large datasets that benefit from tailored multivariate analysis. In this thesis, CRS microscopy was combined with Raman spectroscopy and other label-free nonlinear optical techniques to analyze lipid metabolism in multiple biological systems. We used nonlinear Raman techniques to characterize Meibum secretions in the progression of dry eye disease, where the lipid and protein contributions change in ratio and phase segregation. We employed similar tools to examine lipid droplets in mice livers aboard a spaceflight mission, which lose their retinol content contributing to the onset of nonalcoholic fatty-liver disease. We also focused on atherosclerosis, a disease that revolves around lipid-rich plaques in arterial walls. We examined the lipid content of macrophages, whose variable phenotype gives rise to contrasting healing and inflammatory activities. We also proposed new label-free markers, based on lifetime imaging, for macrophage phenotype, and to detect products of lipid oxidation. Cholesterol was also detected in hepatitis C virus infected cells, and in specific strains of age-related macular degeneration diseased cells by

  16. Optical imaging for breast cancer prescreening

    Directory of Open Access Journals (Sweden)

    Godavarty A


    Full Text Available Anuradha Godavarty,1 Suset Rodriguez,1 Young-Jin Jung,2 Stephanie Gonzalez1 1Optical Imaging Laboratory, Department of Biomedical Engineering, Florida International University, Miami, FL, USA; 2Department of Radiological Science, Dongseo University, Busan, South Korea Abstract: Breast cancer prescreening is carried out prior to the gold standard screening using X-ray mammography and/or ultrasound. Prescreening is typically carried out using clinical breast examination (CBE or self-breast examinations (SBEs. Since CBE and SBE have high false-positive rates, there is a need for a low-cost, noninvasive, non-radiative, and portable imaging modality that can be used as a prescreening tool to complement CBE/SBE. This review focuses on the various hand-held optical imaging devices that have been developed and applied toward early-stage breast cancer detection or as a prescreening tool via phantom, in vivo, and breast cancer imaging studies. Apart from the various optical devices developed by different research groups, a wide-field fiber-free near-infrared optical scanner has been developed for transillumination-based breast imaging in our Optical Imaging Laboratory. Preliminary in vivo studies on normal breast tissues, with absorption-contrasted targets placed in the intramammary fold, detected targets as deep as 8.8 cm. Future work involves in vivo imaging studies on breast cancer subjects and comparison with the gold standard X-ray mammography approach. Keywords: diffuse optical imaging, near-infrared, hand-held devices, breast cancer, prescreening, early detection 

  17. Three-dimensional multifunctional optical coherence tomography for skin imaging (United States)

    Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki


    Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.

  18. Dynamic fluorescence lifetime imaging based on acousto-optic deflectors (United States)

    Yan, Wei; Peng, Xiao; Qi, Jing; Gao, Jian; Fan, Shunping; Wang, Qi; Qu, Junle; Niu, Hanben


    We report a dynamic fluorescence lifetime imaging (D-FLIM) system that is based on a pair of acousto-optic deflectors for the random regions of interest (ROI) study in the sample. The two-dimensional acousto-optic deflector devices are used to rapidly scan the femtosecond excitation laser beam across the sample, providing specific random access to the ROI. Our experimental results using standard fluorescent dyes in live cancer cells demonstrate that the D-FLIM system can dynamically monitor the changing process of the microenvironment in the ROI in live biological samples.

  19. Application of shift-and-add algorithms for imaging objects within biological media (United States)

    Aizert, Avishai; Moshe, Tomer; Abookasis, David


    The Shift-and-Add (SAA) technique is a simple mathematical operation developed to reconstruct, at high spatial resolution, atmospherically degraded solar images obtained from stellar speckle interferometry systems. This method shifts and assembles individual degraded short-exposure images into a single average image with significantly improved contrast and detail. Since the inhomogeneous refractive indices of biological tissue causes light scattering similar to that induced by optical turbulence in the atmospheric layers, we assume that SAA methods can be successfully implemented to reconstruct the image of an object within a scattering biological medium. To test this hypothesis, five SAA algorithms were evaluated for reconstructing images acquired from multiple viewpoints. After successfully retrieving the hidden object's shape, quantitative image quality metrics were derived, enabling comparison of imaging error across a spectrum of layer thicknesses, demonstrating the relative efficacy of each SAA algorithm for biological imaging.

  20. Special issue on high-resolution optical imaging (United States)

    Smith, Peter J. S.; Davis, Ilan; Galbraith, Catherine G.; Stemmer, Andreas


    The pace of development in the field of advanced microscopy is truly breath-taking, and is leading to major breakthroughs in our understanding of molecular machines and cell function. This special issue of Journal of Optics draws attention to a number of interesting approaches, ranging from fluorescence and imaging of unlabelled cells, to computational methods, all of which are describing the ever increasing detail of the dynamic behaviour of molecules in the living cell. This is a field which traditionally, and currently, demonstrates a marvellous interplay between the disciplines of physics, chemistry and biology, where apparent boundaries to resolution dissolve and living cells are viewed in ever more clarity. It is fertile ground for those interested in optics and non-conventional imaging to contribute high-impact outputs in the fields of cell biology and biomedicine. The series of articles presented here has been selected to demonstrate this interdisciplinarity and to encourage all those with a background in the physical sciences to 'dip their toes' into the exciting and dynamic discoveries surrounding cell function. Although single molecule super-resolution microscopy is commercially available, specimen preparation and interpretation of single molecule data remain a major challenge for scientists wanting to adopt the techniques. The paper by Allen and Davidson [1] provides a much needed detailed introduction to the practical aspects of stochastic optical reconstruction microscopy, including sample preparation, image acquisition and image analysis, as well as a brief description of the different variants of single molecule localization microscopy. Since super-resolution microscopy is no longer restricted to three-dimensional imaging of fixed samples, the review by Fiolka [2] is a timely introduction to techniques that have been successfully applied to four-dimensional live cell super-resolution microscopy. The combination of multiple high-resolution techniques

  1. Optical encryption for large-sized images (United States)

    Sanpei, Takuho; Shimobaba, Tomoyoshi; Kakue, Takashi; Endo, Yutaka; Hirayama, Ryuji; Hiyama, Daisuke; Hasegawa, Satoki; Nagahama, Yuki; Sano, Marie; Oikawa, Minoru; Sugie, Takashige; Ito, Tomoyoshi


    We propose an optical encryption framework that can encrypt and decrypt large-sized images beyond the size of the encrypted image using our two methods: random phase-free method and scaled diffraction. In order to record the entire image information on the encrypted image, the large-sized images require the random phase to widely diffuse the object light over the encrypted image; however, the random phase gives rise to the speckle noise on the decrypted images, and it may be difficult to recognize the decrypted images. In order to reduce the speckle noise, we apply our random phase-free method to the framework. In addition, we employ scaled diffraction that calculates light propagation between planes with different sizes by changing the sampling rates.

  2. Multimodal optical imaging for detecting breast cancer (United States)

    Patel, Rakesh; Khan, Ashraf; Wirth, Dennis; Kamionek, Michal; Kandil, Dina; Quinlan, Robert; Yaroslavsky, Anna N.


    The goal of the study was to evaluate wide-field and high-resolution multimodal optical imaging, including polarization, reflectance, and fluorescence for the intraoperative detection of breast cancer. Lumpectomy specimens were stained with 0.05 mg/ml aqueous solution of methylene blue (MB) and imaged. Wide-field reflectance images were acquired between 390 and 750 nm. Wide-field fluorescence images were excited at 640 nm and registered between 660 and 750 nm. High resolution confocal reflectance and fluorescence images were excited at 642 nm. Confocal fluorescence images were acquired between 670 nm and 710 nm. After imaging, the specimens were processed for hematoxylin and eosin (H&E) histopathology. Histological slides were compared with wide-field and high-resolution optical images to evaluate correlation of tumor boundaries and cellular morphology, respectively. Fluorescence polarization imaging identified the location, size, and shape of the tumor in all the cases investigated. Averaged fluorescence polarization values of tumor were higher as compared to normal tissue. Statistical analysis confirmed the significance of these differences. Fluorescence confocal imaging enabled cellular-level resolution. Evaluation and statistical analysis of MB fluorescence polarization values registered from single tumor and normal cells demonstrated higher fluorescence polarization from cancer. Wide-field high-resolution fluorescence and fluorescence polarization imaging shows promise for intraoperative delineation of breast cancers.

  3. Analysis of optical amplifier noise in coherent optical communication systems with optical image rejection receivers

    DEFF Research Database (Denmark)

    Jørgensen, Bo Foged; Mikkelsen, Benny; Mahon, Cathal J.


    performance. Two types of optical image rejection receivers are investigated: a novel, all-optical configuration and the conventional, microwave-based configuration. The analysis shows that local oscillator-spontaneous emission beat noise (LO-SP), signal-spontaneous emission beat noise (S-SP), and spontaneous......A detailed theoretical analysis of optical amplifier noise in coherent optical communication systems with heterodyne receivers is presented. The analysis quantifies in particular how optical image rejection receiver configurations reduce the influence of optical amplifier noise on system......-spontaneous beat noise (SP-SP) can all be reduced by 3 dB, thereby doubling the dynamic range of the optical amplifier. A 2.5-dB improvement in dynamic range has been demonstrated experimentally with the all-optical image rejection configuration. The implications of the increased dynamic range thus obtained...

  4. Intensity interferometry: Optical imaging with kilometer baselines

    CERN Document Server

    Dravins, Dainis


    Optical imaging with microarcsecond resolution will reveal details across and outside stellar surfaces but requires kilometer-scale interferometers, challenging to realize either on the ground or in space. Intensity interferometry, electronically connecting independent telescopes, has a noise budget that relates to the electronic time resolution, circumventing issues of atmospheric turbulence. Extents up to a few km are becoming realistic with arrays of optical air Cherenkov telescopes (primarily erected for gamma-ray studies), enabling an optical equivalent of radio interferometer arrays. Pioneered by Hanbury Brown and Twiss, digital versions of the technique have now been demonstrated, reconstructing diffraction-limited images from laboratory measurements over hundreds of optical baselines. This review outlines the method from its beginnings, describes current experiments, and sketches prospects for future observations.

  5. LDA optical setup using holographic imaging configuration (United States)

    Ghosh, Abhijit; Nirala, A. K.


    This paper describes one of the possible ways for improving fringe quality at LDA measuring volume using a holographic imaging configuration consisting of a single hololens. For its comparative study with a conventional imaging configuration, a complete characterization of fringes formed at the measurement volume by both the configuration is presented. Results indicate the qualitative as well as quantitative improvement of the fringes formed at measurement volume by the holographic imaging configuration. Hence it is concluded that use of holographic imaging configuration for making LDA optical setup is a better choice than the conventional one.

  6. Amplitude image processing by diffractive optics. (United States)

    Cagigal, Manuel P; Valle, Pedro J; Canales, V F


    In contrast to the standard digital image processing, which operates over the detected image intensity, we propose to perform amplitude image processing. Amplitude processing, like low pass or high pass filtering, is carried out using diffractive optics elements (DOE) since it allows to operate over the field complex amplitude before it has been detected. We show the procedure for designing the DOE that corresponds to each operation. Furthermore, we accomplish an analysis of amplitude image processing performances. In particular, a DOE Laplacian filter is applied to simulated astronomical images for detecting two stars one Airy ring apart. We also check by numerical simulations that the use of a Laplacian amplitude filter produces less noisy images than the standard digital image processing.

  7. MR imaging of optic chiasmatic glioma

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seong Sook; Lee, Ho Kyu; Kim, Hyun Jin; Ryu, Meung Sun; Goo, Hyun Woo; Yoon, Chong Hyun; Choi, Choong Gon; Suh, Dae Chul; Ra, Young Shin; Khang, Shin Kwang [University of Ulsan College of Medicine, Seoul (Korea, Republic of)


    To evaluate the MR findings of optic chiasmatic glioma (OCG). MR images were reviewed in 14 patients with histologically proven OCGs and one with neurofibromatosis type 1 (male: female=8:7, mean age=8.5 years.) Tumors were evaluated retrospectively with respect to their size, involvement of the optic pathway, transverse/vertical diameter ratio based on the coronal plane, signal intensities, enhancement pattern, and the presence of a cyst or calcification. Tumors was measured 1.7-5.5 (mean, 3.3) cm in maximum diameter. In ten patients, the optic tracts were involved, and in three, the optic nerves. In 12 patients, tumors had a transverse/vertical diameter ratio of over one, and showed iso (n=5) or low signal intensity (n=10) compared with gray matter at T1-weighted imaging and high signal intensity (n=15) at T2-weighted imaging. Cyst formations were ween in eight patients, and tumors were enhanced strongly and homogeneously in nine and peripherally in four. In seven three was associated hydrocephalus, and in one, calcification. OCG is a suprasellar tumor which can extend into the optic pathway, has a transverse/vertical diameter ratio of more than one, and shows strong and homogeneous enhancement. These MR imaging findings are useful for the differentiation of OCG from other suprasellar tumors.

  8. Stable phantom materials for ultrasound and optical imaging (United States)

    Cabrelli, Luciana C.; Pelissari, Pedro I. B. G. B.; Deana, Alessandro M.; Carneiro, Antonio A. O.; Pavan, Theo Z.


    Phantoms mimicking the specific properties of biological tissues are essential to fully characterize medical devices. Water-based materials are commonly used to manufacture phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages, such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue-mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. A styrene-ethylene/butylene-styrene (SEBS) copolymer in mineral oil samples was made varying the SEBS concentration between 5%-15%, and low-density polyethylene (LDPE) between 0%-9%. Acoustic properties, such as the speed of sound and the attenuation coefficient, were obtained using frequencies ranging from 1-10 MHz, and were consistent with that of soft tissues. These properties were controlled varying SEBS and LDPE concentration. To characterize the optical properties of the samples, the diffuse reflectance and transmittance were measured. Scattering and absorption coefficients ranging from 400 nm-1200 nm were calculated for each compound. SEBS gels are a translucent material presenting low optical absorption and scattering coefficients in the visible region of the spectrum, but the presence of LDPE increased the turbidity. Adding LDPE increased the absorption and scattering of the phantom materials. Ultrasound and photoacoustic images of a heterogeneous phantom made of LDPE/SEBS containing a spherical inclusion were obtained. Annatto dye was added to the inclusion to enhance the optical absorbance. The results suggest that copolymer gels are promising for ultrasound and optical imaging, making them also potentially useful for photoacoustic imaging.

  9. 3D integral imaging with optical processing (United States)

    Martínez-Corral, Manuel; Martínez-Cuenca, Raúl; Saavedra, Genaro; Javidi, Bahram


    Integral imaging (InI) systems are imaging devices that provide auto-stereoscopic images of 3D intensity objects. Since the birth of this new technology, InI systems have faced satisfactorily many of their initial drawbacks. Basically, two kind of procedures have been used: digital and optical procedures. The "3D Imaging and Display Group" at the University of Valencia, with the essential collaboration of Prof. Javidi, has centered its efforts in the 3D InI with optical processing. Among other achievements, our Group has proposed the annular amplitude modulation for enlargement of the depth of field, dynamic focusing for reduction of the facet-braiding effect, or the TRES and MATRES devices to enlarge the viewing angle.

  10. Deformable image registration between pathological images and MR image via an optical macro image. (United States)

    Ohnishi, Takashi; Nakamura, Yuka; Tanaka, Toru; Tanaka, Takuya; Hashimoto, Noriaki; Haneishi, Hideaki; Batchelor, Tracy T; Gerstner, Elizabeth R; Taylor, Jennie W; Snuderl, Matija; Yagi, Yukako


    Computed tomography (CT) and magnetic resonance (MR) imaging have been widely used for visualizing the inside of the human body. However, in many cases, pathological diagnosis is conducted through a biopsy or resection of an organ to evaluate the condition of tissues as definitive diagnosis. To provide more advanced information onto CT or MR image, it is necessary to reveal the relationship between tissue information and image signals. We propose a registration scheme for a set of PT images of divided specimens and a 3D-MR image by reference to an optical macro image (OM image) captured by an optical camera. We conducted a fundamental study using a resected human brain after the death of a brain cancer patient. We constructed two kinds of registration processes using the OM image as the base for both registrations to make conversion parameters between the PT and MR images. The aligned PT images had shapes similar to the OM image. On the other hand, the extracted cross-sectional MR image was similar to the OM image. From these resultant conversion parameters, the corresponding region on the PT image could be searched and displayed when an arbitrary pixel on the MR image was selected. The relationship between the PT and MR images of the whole brain can be analyzed using the proposed method. We confirmed that same regions between the PT and MR images could be searched and displayed using resultant information obtained by the proposed method. In terms of the accuracy of proposed method, the TREs were 0.56±0.39mm and 0.87±0.42mm. We can analyze the relationship between tissue information and MR signals using the proposed method.

  11. Diffuse Optical Tomography for Brain Imaging: Theory (United States)

    Yuan, Zhen; Jiang, Huabei

    Diffuse optical tomography (DOT) is a noninvasive, nonionizing, and inexpensive imaging technique that uses near-infrared light to probe tissue optical properties. Regional variations in oxy- and deoxy-hemoglobin concentrations as well as blood flow and oxygen consumption can be imaged by monitoring spatiotemporal variations in the absorption spectra. For brain imaging, this provides DOT unique abilities to directly measure the hemodynamic, metabolic, and neuronal responses to cells (neurons), and tissue and organ activations with high temporal resolution and good tissue penetration. DOT can be used as a stand-alone modality or can be integrated with other imaging modalities such as fMRI/MRI, PET/CT, and EEG/MEG in studying neurophysiology and pathology. This book chapter serves as an introduction to the basic theory and principles of DOT for neuroimaging. It covers the major aspects of advances in neural optical imaging including mathematics, physics, chemistry, reconstruction algorithm, instrumentation, image-guided spectroscopy, neurovascular and neurometabolic coupling, and clinical applications.

  12. Native spider silk as a biological optical fiber (United States)

    Huby, N.; Vié, V.; Renault, A.; Beaufils, S.; Lefèvre, T.; Paquet-Mercier, F.; Pézolet, M.; Bêche, B.


    In this study, we demonstrate the use of eco-friendly native spider silk as an efficient optical fiber in air, highly bent fibers, and physiological liquid. We also integrated the silk filament in a photonic chip made of polymer microstructures fabricated by UV lithography. The molding process is non-destructive for silk and leads to an efficient micro-optical coupling between silk and synthetic optical structures. These optical performances combined with the unique biocompatibility, bioresorbability, flexibility, and tensile strength of silk filaments pave the way for new applications in biological media and for original biophotonic purposes.

  13. Depth-encoded synthetic aperture optical coherence tomography of biological tissues with extended focal depth. (United States)

    Mo, Jianhua; de Groot, Mattijs; de Boer, Johannes F


    Optical coherence tomography (OCT) has proven to be able to provide three-dimensional (3D) volumetric images of scattering biological tissues for in vivo medical diagnostics. Unlike conventional optical microscopy, its depth-resolving ability (axial resolution) is exclusively determined by the laser source and therefore invariant over the full imaging depth. In contrast, its transverse resolution is determined by the objective's numerical aperture and the wavelength which is only approximately maintained over twice the Rayleigh range. However, the prevailing laser sources for OCT allow image depths of more than 5 mm which is considerably longer than the Rayleigh range. This limits high transverse resolution imaging with OCT. Previously, we reported a novel method to extend the depth-of-focus (DOF) of OCT imaging in Mo et al.Opt. Express 21, 10048 (2013)]. The approach is to create three different optical apertures via pupil segmentation with an annular phase plate. These three optical apertures produce three OCT images from the same sample, which are encoded to different depth positions in a single OCT B-scan. This allows for correcting the defocus-induced curvature of wave front in the pupil so as to improve the focus. As a consequence, the three images originating from those three optical apertures can be used to reconstruct a new image with an extended DOF. In this study, we successfully applied this method for the first time to both an artificial phantom and biological tissues over a four times larger depth range. The results demonstrate a significant DOF improvement, paving the way for 3D high resolution OCT imaging beyond the conventional Rayleigh range.

  14. Multiband optics for imaging systems (Conference Presentation) (United States)

    Sanghera, Jasbinder S.; Gibson, Daniel J.; Bayya, Shyam S.; Nguyen, Vinh Q.; Kotov, Mikhail; McClain, Collin


    There is a strong desire to reduce size and weight of single and multiband IR imaging systems in Intelligence, Surveillance and Reconnaissance (ISR) operations on hand-held, helmet mounted or airborne platforms. NRL is developing new IR glasses that expand the glass map and provide compact solutions to multispectral imaging systems. These glasses were specifically designed to have comparable glass molding temperatures and thermal properties to enable lamination and co-molding of the optics which leads to a reduction in the number of air-glass interfaces (lower Fresnel reflection losses). Our multispectral optics designs using these new materials demonstrate reduced size, complexity and improved performance. This presentation will cover discussions on the new optical materials, multispectral designs, as well fabrication and characterization of new optics. Additionally, graded index (GRIN) optics offer further potential for both weight savings and increased performance but have so far been limited to visible and NIR bands (wavelengths shorter than about 0.9 µm). NRL is developing a capability to extend GRIN optics to longer wavelengths in the infrared by exploiting diffused IR transmitting chalcogenide glasses. These IR-GRIN lenses are compatible with all IR wavebands (SWIR, MWIR and LWIR) and can be used alongside conventional materials. The IR-GRIN lens technology, design space and anti-reflection considerations will be presented in this talk.

  15. Exploiting data redundancy in computational optical imaging. (United States)

    Munro, Peter R T


    We present an algorithm which exploits data redundancy to make computational, coherent, optical imaging more computationally efficient. This algorithm specifically addresses the computation of how light scattered by a sample is collected and coherently detected. It is of greatest benefit in the simulation of broadband optical systems employing coherent detection, such as optical coherence tomography. Although also amenable to time-harmonic data, the algorithm is designed to be embedded within time-domain electromagnetic scattering simulators such as the psuedo-spectral and finite-difference time domain methods. We derive the algorithm in detail as well as criteria which ensure accurate execution of the algorithm. We present simulations that verify the developed algorithm and demonstrate its utility. We expect this algorithm to be important to future developments in computational imaging.

  16. Review of optical breast imaging and spectroscopy (United States)

    Grosenick, Dirk; Rinneberg, Herbert; Cubeddu, Rinaldo; Taroni, Paola


    Diffuse optical imaging and spectroscopy of the female breast is an area of active research. We review the present status of this field and discuss the broad range of methodologies and applications. Starting with a brief overview on breast physiology, the remodeling of vasculature and extracellular matrix caused by solid tumors is highlighted that is relevant for contrast in optical imaging. Then, the various instrumental techniques and the related methods of data analysis and image generation are described and compared including multimodality instrumentation, fluorescence mammography, broadband spectroscopy, and diffuse correlation spectroscopy. We review the clinical results on functional properties of malignant and benign breast lesions compared to host tissue and discuss the various methods to improve contrast between healthy and diseased tissue, such as enhanced spectroscopic information, dynamic variations of functional properties, pharmacokinetics of extrinsic contrast agents, including the enhanced permeability and retention effect. We discuss research on monitoring neoadjuvant chemotherapy and on breast cancer risk assessment as potential clinical applications of optical breast imaging and spectroscopy. Moreover, we consider new experimental approaches, such as photoacoustic imaging and long-wavelength tissue spectroscopy.

  17. Fast optical imaging of human brain function

    Directory of Open Access Journals (Sweden)

    Gabriele Gratton


    Full Text Available Great advancements in brain imaging during the last few decades have opened a large number of new possibilities for neuroscientists. The most dominant methodologies (electrophysiological and magnetic resonance-based methods emphasize temporal and spatial information, respectively. However, theorizing about brain function has recently emphasized the importance of rapid (within 100 ms or so interactions between different elements of complex neuronal networks. Fast optical imaging, and in particular the event-related optical signal (EROS, a technology that has emerged over the last 15 years may provide descriptions of localized (to sub-cm level brain activity with a temporal resolution of less than 100 ms. The main limitations of EROS are its limited penetration, which allows us to image cortical structures not deeper than 3 cm from the surface of the head, and its low signal-to-noise ratio. Advantages include the fact that EROS is compatible with most other imaging methods, including electrophysiological, magnetic resonance, and trans-cranial magnetic stimulation techniques, with which can be recorded concurrently. In this paper we present a summary of the research that has been conducted so far on fast optical imaging, including evidence for the possibility of recording neuronal signals with this method, the properties of the signals, and various examples of applications to the study of human cognitive neuroscience. Extant issues, controversies, and possible future developments are also discussed.

  18. Fourier optics of image formation in LEEM

    Energy Technology Data Exchange (ETDEWEB)

    Pang, A B; Altman, M S [Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong); Mueller, Th; Bauer, Ernst [Physikalisches Institute, Technische Universitaet Clausthal, Leibnizstrasse 4, D-38678 Clausthal-Zellerfeld (Germany)


    A Fourier optics calculation of image formation in low energy electron microscopy (LEEM) is presented. The adaptation of the existing theory for transmission electron microscopy to the treatment of LEEM and other forms of cathode lens electron microscopy is explained. The calculation incorporates imaging errors that are caused by the objective lens (aberrations), contrast aperture (diffraction), imperfect source characteristics, and voltage and current instabilities. It is used to evaluate the appearance of image features that arise from phase objects such as surface steps and amplitude objects that produce what is alternatively called amplitude, reflectivity or diffraction contrast in LEEM. This formalism can be used after appropriate modification to treat image formation in other emission microscopies. Implications for image formation in the latest aberration-corrected instruments are also discussed.

  19. Cloned images and the optical unconscious

    DEFF Research Database (Denmark)

    Romic, Bojana

    ). The hypothesis is that images embody power not only through scientific visualisations, marketing campaigns, celebrity culture or visualisation of ideological messages, but also through the specific visual codes they produce. These codes can be transferred to other images as a 'hidden algorithm', which can later...... the modernist artworks, where bodies and the ground blend from one part-object to another, leading to the experience of formlessness. In my own research I am employing both of these concepts, with an added focus: a codified arrangement of the image (a structure, or gesture, placement of the figures) can...... be stored in a memory of an observer – and later recognised as a pattern (structure) in the another image. The associative process that takes place is usually hidden from the observer, thus the use of the term optical unconscious. As the image gets disseminated via electronic media – 'cloned' is the term...

  20. Optical Properties and In Vitro Biological Studies of Oligonucleotide-Modified Quantum Dots

    Directory of Open Access Journals (Sweden)

    Valérie A. Gérard


    Full Text Available Water-soluble semiconducting nanocrystals or quantum dots (QDs have attracted much interest in recent years due to their tuneable emission and potential applications in photonics and biological imaging. Fluorescence resonance energy transfer (FRET processes are very important for elucidating biochemical mechanisms in vitro, and QDs constitute an excellent substrate for this purpose. In this work, new oligonucleotide-functionalised CdTe-based QDs were prepared, characterised and biologically tested. These QDs demonstrated interesting optical properties as well as remarkable in vitro behaviour and potential for a range of biological applications.

  1. Combining Different Modalities for 3D Imaging of Biological Objects

    CERN Document Server

    Tsyganov, E; Kulkarni, P; Mason, R; Parkey, R; Seliuonine, S; Shay, J; Soesbe, T; Zhezher, V; Zinchenko, A I


    A resolution enhanced NaI(Tl)-scintillator micro-SPECT device using pinhole collimator geometry has been built and tested with small animals. This device was constructed based on a depth-of-interaction measurement using a thick scintillator crystal and a position sensitive PMT to measure depth-dependent scintillator light profiles. Such a measurement eliminates the parallax error that degrades the high spatial resolution required for small animal imaging. This novel technique for 3D gamma-ray detection was incorporated into the micro-SPECT device and tested with a $^{57}$Co source and $^{98m}$Tc-MDP injected in mice body. To further enhance the investigating power of the tomographic imaging different imaging modalities can be combined. In particular, as proposed and shown in this paper, the optical imaging permits a 3D reconstruction of the animal's skin surface thus improving visualization and making possible depth-dependent corrections, necessary for bioluminescence 3D reconstruction in biological objects. ...

  2. Optical coherence tomography for endodontic imaging (United States)

    van Soest, G.; Shemesh, H.; Wu, M.-K.; van der Sluis, L. W. M.; Wesselink, P. R.


    In root canal therapy, complications frequently arise as a result of root fracture or imperfect cleaning of fins and invaginations. To date, there is no imaging method for nondestructive in vivo evaluation of the condition of the root canal, during or after treatment. There is a clinical need for a technique to detect defects before they give rise to complications. In this study we evaluate the ability of optical coherence tomography (OCT) to image root canal walls, and its capacity to identify complicating factors in root canal treatment. While the potential of OCT to identify caries has been explored before, endodontic imaging has not been reported. We imaged extracted lower front teeth after endodontic preparation and correlated these images to histological sections. A 3D OCT pullback scan was made with an endoscopic rotating optical fiber probe inside the root canal. All oval canals, uncleaned fins, risk zones, and one perforation that were detected by histology were also imaged by OCT. As an example of an area where OCT has clinical potential, we present a study of vertical root fracture identification with OCT.

  3. Radionuclide Imaging Technologies for Biological Systems

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Calvin R. [Duke Univ., Durham, NC (United States); Reid, Chantal D. [Duke Univ., Durham, NC (United States); Weisenberger, Andrew G. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)


    The main objective of this project is to develop technologies and experimental techniques for studying the dynamics of physiological responses of plants to changes in their interface with the local environment and to educate a new generation of scientists in an interdisciplinary environment of biology, physics and engineering. Also an important goal is to perform measurements to demonstrate the new data that can be produced and made available to the plant-biology community using the imaging technologies and experimental techniques developed in this project. The study of the plant-environment interface includes a wide range of topics in plant physiology, e.g., the root-soil interface, resource availability, impact of herbivores, influence of microbes on root surface, and responses to toxins in the air and soil. The initial scientific motivation for our work is to improve understanding of the mechanisms for physiological responses to abrupt changes in the local environment, in particular, the responses that result in short-term adjustments in resource (e.g., sugars, nutrients and water) allocations. Data of time-dependent responses of plants to environmental changes are essential in developing mechanistic models for substance intake and resource allocation. Our approach is to use radioisotope tracing techniques to study whole-plant and plant organ (e.g., leaves, stems, roots) dynamical responses to abrupt changes in environmental conditions such as concentration of CO2 in the atmosphere, nutrient availability and lighting. To this aim we are collaborating with the Radiation Detector and Imaging Group at the Thomas Jefferson National Laboratory Facility (JLab) to develop gamma-ray and beta particle imaging systems optimized for plant studies. The radioisotope tracing measurements are conducted at the Phytotron facility at Duke University. The Phytotron is a controlled environment plant research facility with a variety of plant growth chambers. One chamber

  4. Physical Optics Based Computational Imaging Systems (United States)

    Olivas, Stephen Joseph

    There is an ongoing demand on behalf of the consumer, medical and military industries to make lighter weight, higher resolution, wider field-of-view and extended depth-of-focus cameras. This leads to design trade-offs between performance and cost, be it size, weight, power, or expense. This has brought attention to finding new ways to extend the design space while adhering to cost constraints. Extending the functionality of an imager in order to achieve extraordinary performance is a common theme of computational imaging, a field of study which uses additional hardware along with tailored algorithms to formulate and solve inverse problems in imaging. This dissertation details four specific systems within this emerging field: a Fiber Bundle Relayed Imaging System, an Extended Depth-of-Focus Imaging System, a Platform Motion Blur Image Restoration System, and a Compressive Imaging System. The Fiber Bundle Relayed Imaging System is part of a larger project, where the work presented in this thesis was to use image processing techniques to mitigate problems inherent to fiber bundle image relay and then, form high-resolution wide field-of-view panoramas captured from multiple sensors within a custom state-of-the-art imager. The Extended Depth-of-Focus System goals were to characterize the angular and depth dependence of the PSF of a focal swept imager in order to increase the acceptably focused imaged scene depth. The goal of the Platform Motion Blur Image Restoration System was to build a system that can capture a high signal-to-noise ratio (SNR), long-exposure image which is inherently blurred while at the same time capturing motion data using additional optical sensors in order to deblur the degraded images. Lastly, the objective of the Compressive Imager was to design and build a system functionally similar to the Single Pixel Camera and use it to test new sampling methods for image generation and to characterize it against a traditional camera. These computational

  5. A review of imaging techniques for systems biology

    Directory of Open Access Journals (Sweden)

    Po Ming J


    Full Text Available Abstract This paper presents a review of imaging techniques and of their utility in system biology. During the last decade systems biology has matured into a distinct field and imaging has been increasingly used to enable the interplay of experimental and theoretical biology. In this review, we describe and compare the roles of microscopy, ultrasound, CT (Computed Tomography, MRI (Magnetic Resonance Imaging, PET (Positron Emission Tomography, and molecular probes such as quantum dots and nanoshells in systems biology. As a unified application area among these different imaging techniques, examples in cancer targeting are highlighted.

  6. Live imaging in Drosophila: The optical and genetic toolkits. (United States)

    Rebollo, Elena; Karkali, Katerina; Mangione, Federica; Martín-Blanco, Enrique


    Biological imaging based on light microscopy comes at the core of the methods that let us understanding morphology and its dynamics in synergy to the spatiotemporal distribution of cellular and molecular activities as the organism develops and becomes functional. Non-linear optical tools and superesolution methodologies are under constant development and their applications to live imaging of whole organisms keep improving as we speak. Genetically coded biosensors, multicolor clonal methods and optogenetics in different organisms and, in particular, in Drosophila follow equivalent paths. We anticipate a brilliant future for live imaging providing the roots for the holistic understanding, rather than for individual parts, of development and function at the whole-organism level.

  7. Image Distortion of Optical Coherence Tomography

    Institute of Scientific and Technical Information of China (English)

    安源; 姚建铨


    A kind of image distortion in Optical Coherence Tomography (OCT) resulted from average refractive index changes between structures of bio-tissue is discussed for the first time.Analysis is given on following situations:1) Exact refraction index changes between microstructures;2)The gradient of average refractive index change between different tissue layers is parallel to the probe beam;3) The gradient of average refractive index change is vertical to the probe beam.The results show that the image distortion of situation 1) is usually negligible;in situation 2) there is a spread or shrink effect without relative location error; however,in situation 3) there is a significant image error inducing relative location displacement between different structures.Preliminary design to eliminate the distortion is presented,the method of which mainly based on the image classification and pixel array re-arrangement.

  8. Adaptive optics OCT using 1060nm swept source and dual deformable lenses for human retinal imaging (United States)

    Jian, Yifan; Lee, Sujin; Cua, Michelle; Miao, Dongkai; Bonora, Stefano; Zawadzki, Robert J.; Sarunic, Marinko V.


    Adaptive optics concepts have been applied to the advancement of biological imaging and microscopy. In particular, AO has also been very successfully applied to cellular resolution imaging of the retina, enabling visualization of the characteristic mosaic patterns of the outer retinal layers using flood illumination fundus photography, Scanning Laser Ophthalmoscopy (SLO), and Optical Coherence Tomography (OCT). Despite the high quality of the in vivo images, there has been a limited uptake of AO imaging into the clinical environment. The high resolution afforded by AO comes at the price of limited field of view and specialized equipment. The implementation of a typical adaptive optics imaging system results in a relatively large and complex optical setup. The wavefront measurement is commonly performed using a Hartmann-Shack Wavefront Sensor (HS-WFS) placed at an image plane that is optically conjugated to the eye's pupil. The deformable mirror is also placed at a conjugate plane, relaying the wavefront corrections to the pupil. Due to the sensitivity of the HS-WFS to back-reflections, the imaging system is commonly constructed from spherical mirrors. In this project, we present a novel adaptive optics OCT retinal imaging system with significant potential to overcome many of the barriers to integration with a clinical environment. We describe in detail the implementation of a compact lens based wavefront sensorless adaptive optics (WSAO) 1060nm swept source OCT human retinal imaging system with dual deformable lenses, and present retinal images acquired in vivo from research volunteers.

  9. 7th International Workshop on Advanced Optical Imaging and Metrology

    CERN Document Server


    In continuation of the FRINGE Workshop Series this Proceeding contains all contributions presented at the 7. International Workshop on Advanced Optical Imaging and Metrology. The FRINGE Workshop Series is dedicated to the presentation, discussion and dissemination of recent results in Optical Imaging and Metrology. Topics of particular interest for the 7. Workshop are: - New methods and tools for the generation, acquisition, processing, and evaluation of data in Optical Imaging and Metrology (digital wavefront engineering, computational imaging, model-based reconstruction, compressed sensing, inverse problems solution) - Application-driven technologies in Optical Imaging and Metrology (high-resolution, adaptive, active, robust, reliable, flexible, in-line, real-time) - High-dynamic range solutions in Optical Imaging and Metrology (from macro to nano) - Hybrid technologies in Optical Imaging and Metrology (hybrid optics, sensor and data fusion, model-based solutions, multimodality) - New optical sensors, imagi...

  10. Novel optical system for neonatal brain imaging (United States)

    Chen, Yu; Zhou, Shuoming; Nioka, Shoko; Chance, Britton; Anday, Endla; Ravishankar, Sudha; Delivoria-Papadopoulos, Maria


    A highly portable, fast, safe and affordable imaging system that provides interpretable images of brain function in full- and pre-term neonates within a few seconds has been applied to neonates with normal and pathological states. We have used a uniquely sensitive optical tomography system, termed phased array, which has revealed significant functional responses, particularly to parietal stimulation in neonate brain. This system can indicate the blood concentration and oxygenation change during the parietal brain activation in full- and pre-term neonates. The preliminary clinical results, especially a longitudinal study of a cardiac arrest neonate, suggest a variety of future applications.

  11. Electro-optic imaging Fourier transform spectrometer (United States)

    Chao, Tien-Hsin (Inventor); Znod, Hanying (Inventor)


    An Electro-Optic Imaging Fourier Transform Spectrometer (EOIFTS) for Hyperspectral Imaging is described. The EOIFTS includes an input polarizer, an output polarizer, and a plurality of birefringent phase elements. The relative orientations of the polarizers and birefringent phase elements can be changed mechanically or via a controller, using ferroelectric liquid crystals, to substantially measure the spectral Fourier components of light propagating through the EIOFTS. When achromatic switches are used as an integral part of the birefringent phase elements, the EIOFTS becomes suitable for broadband applications, with over 1 micron infrared bandwidth.

  12. Magneto-optical imaging of exotic superconductors (United States)

    van der Beek, C. J.; Losco, J.; Konczykowski, M.; Pari, P.; Shibauchi, T.; Shishido, H.; Matsuda, Y.


    We have constructed a novel compact cryostat for optical measurements at temperatures below 2 K. The desktop cryostat, small enough to be placed under the objective of a standard commercial polarized light microscope, functions in a single shot mode, with a five hour autonomy at 1.5 K. Central to its conception are four charcoal pumps for adsorption and desorption of He contained in a closed circuit, and novel thermal switches allowing for thermalization of the pumps and of the two 1 K pots. The latter are connected to the 1" diameter sample holder through braids. Sample access is immediate, through the simple removal of the optical windows. In this contribution, we shall present first results on magneto-optical imaging of flux penetration in the heavy-fermion superconductor CeCoIn5.

  13. IOT Overview: Optical Spectro-Imagers (United States)

    Patat, F.

    Taking the FORS instruments as a representative case, I review the Calibration Plan for optical spectro-imagers currently offered at ESO, discussing various aspects related both to the scientific outcome and the instrument/site monitoring. I also describe ongoing and future calibration projects planned by the Instrument Operations Teams, trying to give an objective view on the limitations of the Calibration Plans currently implemented at ESO for this class of instruments.

  14. Porphyrin-magnetite nanoconjugates for biological imaging

    LENUS (Irish Health Repository)

    Nowostawska, Malgorzata


    Abstract Background The use of silica coated magnetic nanoparticles as contrast agents has resulted in the production of highly stable, non-toxic solutions that can be manipulated via an external magnetic field. As a result, the interaction of these nanocomposites with cells is of vital importance in understanding their behaviour and biocompatibility. Here we report the preparation, characterisation and potential application of new "two-in-one" magnetic fluorescent nanocomposites composed of silica-coated magnetite nanoparticles covalently linked to a porphyrin moiety. Method The experiments were performed by administering porphyrin functionalised silica-coated magnetite nanoparticles to THP-1 cells, a human acute monocytic leukaemia cell line. Cells were cultured in RPMI 1640 medium with 25 mM HEPES supplemented with heat-inactivated foetal bovine serum (FBS). Results We have synthesised, characterised and analysed in vitro, a new multimodal (magnetic and fluorescent) porphyrin magnetic nanoparticle composite (PMNC). Initial co-incubation experiments performed with THP-1 macrophage cells were promising; however the PMNC photobleached under confocal microscopy study. β-mercaptoethanol (β-ME) was employed to counteract this problem and resulted not only in enhanced fluorescence emission, but also allowed for elongated imaging and increased exposure times of the PMNC in a cellular environment. Conclusion Our experiments have demonstrated that β-ME visibly enhances the emission intensity. No deleterious effects to the cells were witnessed upon co-incubation with β-ME alone and no increases in background fluorescence were recorded. These results should present an interest for further development of in vitro biological imaging techniques.

  15. Strain-sensitive upconversion for imaging biological forces (Conference Presentation) (United States)

    Lay, Alice; Wisser, Michael; Lin, Yu; Narayan, Tarun; Krieg, Michael; Atre, Ashwin; Goodman, Miriam; Dionne, Jennifer A.


    Nearly all diseases can be traced back to abnormal mechanotransduction, but few sensors can reliably measure biologically-relevant forces in vivo. Here, we investigate sub-25nm lanthanide-doped upconverting nanoparticles as novel optical force probes, which provide several biocompatible features: sharp emission peaks with near infrared illumination, a high signal-to-noise ratio, and photostability. To increase force sensitivity, we include d-metal doping in the nanoparticles; the d-metal siphons energy from the lanthanide ions with an efficiency that varies with pressure. We synthesize cubic-phase NaYF4: Er3+,Yb3+ nanoparticles doped with 0-5% Mn2+ and compress them in a hydrostatic environment using a diamond anvil cell. When illuminated at 980nm, the nanoparticles show sharp emission peaks centered at wavelengths of 522nm, 545nm, and 660nm. In 20nN increments, up to 700nN, the ratio of the red-to-green peaks in 0% Mn-doped nanoparticles increases by nearly 30%, resulting in a perceived color change from orange to red. In contrast, the 1% Mn-doped samples exhibit little color change but a large 40% decrease in upconversion intensity. In both cases, the red-to-green ratio varies linearly with strain and the optical properties are recoverable upon release. We further use atomic force microscopy to characterize optical responses at lower, pico-Newton to nano-Newton forces. To demonstrate in vivo imaging capabilities, we incubate C. elegans with nanoparticles dispersed in buffer solution (5mg/mL concentration) and image forces involved in digestion using confocal microscopy. Our nanoparticles provide a platform for the first, non-genetically-encoded in vivo force sensors, and we describe routes to increase their sensitivity to the single-pN range.

  16. Luminescent Silica Nanoparticles Featuring Collective Processes for Optical Imaging. (United States)

    Rampazzo, Enrico; Prodi, Luca; Petrizza, Luca; Zaccheroni, Nelsi


    The field of nanoparticles has successfully merged with imaging to optimize contrast agents for many detection techniques. This combination has yielded highly positive results, especially in optical and magnetic imaging, leading to diagnostic methods that are now close to clinical use. Biological sciences have been taking advantage of luminescent labels for many years and the development of luminescent nanoprobes has helped definitively in making the crucial step forward in in vivo applications. To this end, suitable probes should present excitation and emission within the NIR region where tissues have minimal absorbance. Among several nanomaterials engineered with this aim, including noble metal, lanthanide, and carbon nanoparticles and quantum dots, we have focused our attention here on luminescent silica nanoparticles. Many interesting results have already been obtained with nanoparticles containing only one kind of photophysically active moiety. However, the presence of different emitting species in a single nanoparticle can lead to diverse properties including cooperative behaviours. We present here the state of the art in the field of silica luminescent nanoparticles exploiting collective processes to obtain ultra-bright units suitable as contrast agents in optical imaging and optical sensing and for other high sensitivity applications.

  17. Imaging Cutaneous T-Cell Lymphoma with Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hans Christian Ring


    Full Text Available Aim: To investigate the presentation of a patch-stage cutaneous T-cell lymphoma (CTCL using optical coherence tomography (OCT. Methods: A patient with a patch caused by CTCL was photographed digitally, OCT-scanned and biopsied. A normal skin area adjacent to the patch was OCT-scanned for comparison, but not biopsied. The OCT image and the histological image were compared. Results: The OCT images illustrated a thickened and hyperreflective stratum corneum. OCT also demonstrated several elongated hyporeflective structures in the dermis. The largest structure was measured to have a width of 0.13 mm. A good immediate correlation was found between histology and OCT imaging of the sample. Conclusion: The aetiology of the elongated structures is thought to be lymphomatous infiltrates. Similar findings have been described in ocular lymphoma and may therefore be an important characteristic of cutaneous lymphoma. It may further be speculated that the differences in OCT images may reflect the biological behaviour of the infiltrate. This observation therefore suggests that OCT imaging may be a relevant tool for the in vivo investigation of mycosis fungoides and other CTCLs, but in order to verify these observed patterns in OCT imaging, further investigations will be required.

  18. Optical imaging of oral pathological tissue using optical coherence tomography and synchrotron radiation computed microtomography (United States)

    Cânjǎu, Silvana; Todea, Carmen; Sinescu, Cosmin; Negrutiu, Meda L.; Duma, Virgil; Mǎnescu, Adrian; Topalǎ, Florin I.; Podoleanu, Adrian Gh.


    The efforts aimed at early diagnosis of oral cancer should be prioritized towards developing a new screening instrument, based on optical coherence tomography (OCT), to be used directly intraorally, able to perform a fast, real time, 3D and non-invasive diagnosis of oral malignancies. The first step in this direction would be to optimize the OCT image interpretation of oral tissues. Therefore we propose plastination as a tissue preparation method that better preserves three-dimensional structure for study by new optical imaging techniques. The OCT and the synchrotron radiation computed microtomography (micro-CT) were employed for tissue sample analyze. For validating the OCT results we used the gold standard diagnostic procedure for any suspicious lesion - histopathology. This is a preliminary study of comparing features provided by OCT and Micro-CT. In the conditions of the present study, OCT proves to be a highly promising imaging modality. The use of x-ray based topographic imaging of small biological samples has been limited by the low intrinsic x-ray absorption of non-mineralized tissue and the lack of established contrast agents. Plastination can be used to enhance optical imagies of oral soft tissue samples.

  19. Computational optical sensing and imaging: introduction to feature issue. (United States)

    Gerwe, David R; Harvey, Andrew; Gehm, Michael E


    The 2012 Computational Optical Sensing and Imaging (COSI) conference of the Optical Society of America was one of six colocated meetings composing the Imaging and Applied Optics Congress held in Monterey, California, 24-28 June. COSI, together with the Imaging Systems and Applications, Optical Sensors, Applied Industrial Optics, and Optical Remote Sensing of the Environment conferences, brought together a diverse group of scientists and engineers sharing a common interest in measuring and processing of information carried by optical fields. This special feature includes several papers based on presentations given at the 2012 COSI conference as well as independent contributions, which together highlight several important trends.

  20. Imaging Granulomatous Lesions with Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Christina Banzhaf


    Full Text Available Aim: To investigate and compare the presentation of granulomatous lesions in optical coherence tomography (OCT images and compare this to previous studies of nonmelanoma skin tumors. Methods: Two patients with granulomas, tophi and granuloma annulare (GA, respectively, were photographed digitally, OCT-scanned and biopsied in the said order. Normal skin was OCT-scanned for comparison, but not biopsied. The OCT images from each lesion were compared with their histologic images as well as with OCT images with similar characteristics obtained from nonmelanoma skin tumors. Results: The OCT images of the tophi showed hyperreflective, rounded cloud-like structures in dermis, their upper part sharply delineated by a hyporeflective fringe. The deeper areas appeared blurred. The crystalline structures were delineated by a hyporeflective fringe. OCT images of GA showed two different structures in dermis: a hyporeflective rounded one, and one that was lobulated and wing-like. Conclusion: Granulomatous tissue surrounding urate deposits appeared as a clear hyporeflective fringe surrounding a light, hyperreflective area. The urate crystals appeared as hyperreflective areas, shielding the deeper part of dermis, meaning OCT could only visualize the upper part of the lesions. The lobulated, wing-like structure in GA may resemble diffuse GA or a dense lymphocytic infiltrate as seen on histology. The rounded structure in GA may represent an actual granuloma or either diffuse GA or a dense lymphocytic infiltrate as described above. This case suggests that OCT images granulomatous tissue as absorbent, hyporeflective areas, and urate crystals appear as reflective areas, obscuring the underlying tissue. In GA a new image shape looking like a wing has been found. The frequency, specificity and sensitivity of this new pattern in OCT imaging will require further studies.

  1. SU 8 used as optical waveguide in integrated optical microsensor for biological applications (United States)

    Műller, Raluca; Obreja, P.; Kusko, M.; Esinenco, D.; Tibeica, C.; Conache, G.; Buia, L.; Apostol, D.; Damian, V.; Mateescu, M.; Diaconu, Mirela; Moldovan, Lucia


    We present preliminary experiments for an integrated optical sensor based on a Mach-Zehnder interferometer for biological applications. The sensor is sensitive to refractive index change produced by the presence of a biological species in the cladding of the optical waveguide. A "window" can be patterned in the upper cladding, so that the evanescent wave can be in direct contact with the environmental (the sensitive layer). We investigated as optical waveguides a new material, SU-8, a negative photoresist well known from the development of 3D micromachmed structures. We structured, by photolithographic techniques, rib and channel optical waveguides. We studied the influence of the silicon substrate on propagation losses and the possibility to use these losses for the selective attenuation of the higher order modes on the vertical direction. As biological materials we experimented collagen, which is a bio-polymer which can bind different enzymes or antibodies.

  2. High resolution 3D imaging of living cells with sub-optical wavelength phonons (United States)

    Pérez-Cota, Fernando; Smith, Richard J.; Moradi, Emilia; Marques, Leonel; Webb, Kevin F.; Clark, Matt


    Label-free imaging of living cells below the optical diffraction limit poses great challenges for optical microscopy. Biologically relevant structural information remains below the Rayleigh limit and beyond the reach of conventional microscopes. Super-resolution techniques are typically based on the non-linear and stochastic response of fluorescent labels which can be toxic and interfere with cell function. In this paper we present, for the first time, imaging of live cells using sub-optical wavelength phonons. The axial imaging resolution of our system is determined by the acoustic wavelength (λa = λprobe/2n) and not on the NA of the optics allowing sub-optical wavelength acoustic sectioning of samples using the time of flight. The transverse resolution is currently limited to the optical spot size. The contrast mechanism is significantly determined by the mechanical properties of the cells and requires no additional contrast agent, stain or label to image the cell structure. The ability to breach the optical diffraction limit to image living cells acoustically promises to bring a new suite of imaging technologies to bear in answering exigent questions in cell biology and biomedicine.

  3. Compressive optical image watermarking using joint Fresnel transform correlator architecture (United States)

    Li, Jun; Zhong, Ting; Dai, Xiaofang; Yang, Chanxia; Li, Rong; Tang, Zhilie


    A new optical image watermarking technique based on compressive sensing using joint Fresnel transform correlator architecture has been presented. A secret scene or image is first embedded into a host image to perform optical image watermarking by use of joint Fresnel transform correlator architecture. Then, the watermarked image is compressed to much smaller signal data using single-pixel compressive holographic imaging in optical domain. At the received terminal, the watermarked image is reconstructed well via compressive sensing theory and a specified holographic reconstruction algorithm. The preliminary numerical simulations show that it is effective and suitable for optical image security transmission in the coming absolutely optical network for the reason of the completely optical implementation and largely decreased holograms data volume.

  4. Confocal imaging of protein distributions in porous silicon optical structures

    Energy Technology Data Exchange (ETDEWEB)

    De Stefano, Luca [Institute for Microelectronics and Microsystems, Department of Naples, National Council of Research, Via P Castellino 111, 80131 Naples (Italy); D' Auria, Sabato [Institute of Protein Biochemistry, National Council of Research, Via P Castellino 111, 80131 Naples (Italy)


    The performances of porous silicon optical biosensors depend strongly on the arrangement of the biological probes into their sponge-like structures: it is well known that in this case the sensing species do not fill the pores but instead cover their internal surface. In this paper, the direct imaging of labelled proteins into different porous silicon structures by using a confocal laser microscope is reported. The distribution of the biological matter in the nanostructured material follows a Gaussian behaviour which is typical of the diffusion process in the porous media but with substantial differences between a porous silicon monolayer and a multilayer such as a Bragg mirror. Even if semi-quantitative, the results can be very useful in the design of the porous silicon based biosensing devices.

  5. Optical Brain Imaging: A Powerful Tool for Neuroscience. (United States)

    Zhu, Xinpei; Xia, Yanfang; Wang, Xuecen; Si, Ke; Gong, Wei


    As the control center of organisms, the brain remains little understood due to its complexity. Taking advantage of imaging methods, scientists have found an accessible approach to unraveling the mystery of neuroscience. Among these methods, optical imaging techniques are widely used due to their high molecular specificity and single-molecule sensitivity. Here, we overview several optical imaging techniques in neuroscience of recent years, including brain clearing, the micro-optical sectioning tomography system, and deep tissue imaging.

  6. Performance of laser based optical imaging system (United States)

    Shah, Dhrupesh S.; Banerjee, Arup; Vora, Anup; Biswas, Amiya; Patel, Naimesh; Kurulkar, Amit; Dutt, Ashutosh


    Day night imaging application requires high dynamic range optical imaging system to detect targets of interest covering mid-day (>32000 Lux)[1], and moonless night ( 1mLux)[1] under clear sky- (visibility of >10km, atmospheric loss of 500m, atmospheric loss of >15dB/Km) conditions. Major governing factors for development of such camera systems are (i) covert imaging with ability to identify the target, (ii) imaging irrespective to the scene background, (iii) reliable operation , (iv) imaging capabilities in inclement weather conditions, (v) resource requirement vs availability power & mass, (vi) real-time data processing, (vii) self-calibration, and (viii) cost. Identification of optimum spectral band of interest is most important to meet these requirements. Conventional detection systems sensing in MWIR and LWIR band has certain draw backs in terms of target detection capabilities, susceptibility to background and huge thermo-mechanical resource requirement. Alternatively, range gated imaging camera system sensing in NIR/SWIR spectrum has shown significant potential to detect wide dynamic range targets. ToF Camera configured in NIR band has certain advantages in terms of Focal Plane Assembly (FPA) development with large format detectors and thermo-mechanical resource requirement compared to SWIR band camera configuration. In past, ToF camera systems were successfully configured in NIR spectrum using silicon based Electron Multiplying CCD (EMCCD), Intensifier CCD (ICCD) along with Gating device and pulsed laser source having emission in between 800nm to 900nm. However, these systems have a very low dynamic range and not suitable for clear sky mid-day conditions. Recently silicon based scientific grade CMOS image sensors have shown significant improvement in terms of high NIR responsivity and available in bigger formats (5MP or more), adequate Full well capacity for day time imaging (>30Ke), very low readout noise (<2e) required for night imaging and higher frame

  7. Nanoscale optical imaging of semiconductor nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Boehmler, Miriam; Hartschuh, Achim [Department Chemie, CeNS, Ludwig-Maximilians-Universitaet Muenchen (Germany); Myalitsin, Anton; Mews, Alf [Department Chemie, Universitaet Hamburg (Germany)


    Inorganic semiconducting nanowires (NWs) feature size-related optical properties which make them interesting for a wide range of applications, e.g. nanoscale optoelectronics, sensors, and photovoltaics. Their relevant length scales that are determined by nanowire diameter and exciton Bohr radius, however, can not be resolved by conventional diffraction limited methods. We illustrate the prospects of tip-enhanced near-field optical microscopy (TENOM) as a method to investigate single nanowires. In TENOM a sharp metallic tip acts as optical antenna thereby enhancing the detected signal and increasing the optical resolution to about 15 nm. We present our investigations of CdSe NWs which have been grown by the wet chemical solution liquid solid technique. Here, TENOM provides the possibility to simultaneously image photoluminescence (PL) as well as Raman scattering of individual NWs with nanoscale resolution. We observe spatial variations of the PL intensity and energy on a length scale of about 15 nm indicating crystal phase transitions and diameter fluctuations.

  8. Functionalized nanoparticles for biological imaging and detection applications (United States)

    Mei, Bing C.

    Semiconductor quantum dots (QDs) and gold nanoparticles (AuNPs) have gained tremendous attention in the last decade as a result of their size-dependent spectroscopic properties. These nanoparticles have been a subject of intense study to bridge the gap between macroscopic and atomic behavior, as well as to generate new materials for novel applications in therapeutics, biological sensing, light emitting devices, microelectronics, lasers, and solar cells. One of the most promising areas for the use of these nanoparticles is in biotechnology, where their size-dependent optical properties are harnessed for imaging and sensing applications. However, these nanoparticles, as synthesized, are often not stable in aqueous media and lack simple and reliable means of covalently linking to biomolecules. The focus of this work is to advance the progress of these nanomaterials for biotechnology by synthesizing them, characterizing their optical properties and rendering them water-soluble and functional while maintaining their coveted optical properties. QDs were synthesized by an organometallic chemical procedure that utilizes coordinating solvents to provide brightly luminescent nanoparticles. The optical interactions of these QDs were studied as a function of concentration to identify particle size-dependent optimal concentrations, where scattering and indirection excitation are minimized and the amount light observed per particle is maximized. Both QDs and AuNPs were rendered water-soluble and stable in a broad range of biologically relevant conditions by using a series of ligands composed of dihydrolipoic acid (DHLA) appended to poly(ethylene glycol) methyl ether. By studying the stability of the surface modified AuNPs, we revealed some interesting information regarding the role of the surface ligand on the nanoparticle stability (i.e. solubility in high salt concentration, resistance to dithiothreitol competition and cyanide decomposition). Furthermore, the nanoparticles

  9. Functional imaging in bulk tissue specimens using optical emission tomography: fluorescence preservation during optical clearing (United States)

    Sakhalkar, H. S.; Dewhirst, M.; Oliver, T.; Cao, Y.; Oldham, M.


    Optical emission computed tomography (optical-ECT) is a technique for imaging the three-dimensional (3D) distribution of fluorescent probes in biological tissue specimens with high contrast and spatial resolution. In optical-ECT, functional information can be imaged by (i) systemic application of functional labels (e.g. fluorophore labelled proteins) and/or (ii) endogenous expression of fluorescent reporter proteins (e.g. red fluorescent protein (RFP), green fluorescent protein (GFP)) in vivo. An essential prerequisite for optical-ECT is optical clearing, a procedure where tissue specimens are made transparent to light by sequential perfusion with fixing, dehydrating and clearing agents. In this study, we investigate clearing protocols involving a selection of common fixing (4% buffered paraformaldehyde (PFA), methanol and ethanol), dehydrating (methanol and ethanol) and clearing agents (methyl salicylate and benzyl-alcohol-benzyl-benzoate (BABB)) in order to determine a 'fluorescence friendly' clearing procedure. Cell culture experiments were employed to optimize the sequence of chemical treatments that best preserve fluorescence. Texas red (TxRed), fluorescein isothiocyanate (FITC), RFP and GFP were tested as fluorophores and fluorescent reporter proteins of interest. Fluorescent and control cells were imaged on a microscope using a DSred2 and FITC filter set. The most promising clearing protocols of cell culture experiments were applied to whole xenograft tumour specimens, to test their effectiveness in large unsectioned samples. Fluorescence of TxRed/FITC fluorophores was not found to be significantly affected by any of the test clearing protocols. RFP and GFP fluorescence, however, was found to be significantly greater when cell fixation was in ethanol. Fixation in either PFA or methanol resulted in diminished fluorescence. After ethanol fixation, the RFP and GFP fluorescence proved remarkably robust to subsequent exposure to either methyl salicylate or BABB

  10. Optical Methods and Instrumentation in Brain Imaging and Therapy

    CERN Document Server


    This book provides a comprehensive up-to-date review of optical approaches used in brain imaging and therapy. It covers a variety of imaging techniques including diffuse optical imaging, laser speckle imaging, photoacoustic imaging and optical coherence tomography. A number of laser-based therapeutic approaches are reviewed, including photodynamic therapy, fluorescence guided resection and photothermal therapy. Fundamental principles and instrumentation are discussed for each imaging and therapeutic technique. Represents the first publication dedicated solely to optical diagnostics and therapeutics in the brain Provides a comprehensive review of the principles of each imaging/therapeutic modality Reviews the latest advances in instrumentation for optical diagnostics in the brain Discusses new optical-based therapeutic approaches for brain diseases

  11. Probing biological light-harvesting phenomena by optical cavities

    CERN Document Server

    Caruso, Filippo; Solano, Enrique; Huelga, Susana F; Aspuru-Guzik, Alán; Plenio, Martin B


    We propose a driven optical cavity quantum electrodynamics (QED) set up aimed at directly probing energy transport dynamics in photosynthetic biomolecules. We show that detailed information concerning energy transfer paths and delocalization of exciton states can be inferred (and exciton energies estimated) from the statistical properties of the emitted photons. This approach provides us with a novel spectroscopic tool for the interrogation of biological systems in terms of quantum optical phenomena which have been usually studied for atomic or solid-state systems, e.g. trapped atoms and semiconductor quantum dots.

  12. Design parameters for wearable optical imagers (United States)

    Akin, Ata; Kim, Sanghyun; Pourrezaei, Kambiz; Chance, Britton; Nioka, Shoko


    This paper summarizes the design steps that are followed during the development of the portable optical imager for breast cancer screening. The design steps considered the parameters such as total power consumption versus battery weight and size, speed of data acquisition versus cost and complexity of the design (functionality), graphical display versus operating system choice. We have used a single board computer system that uses Windows CE as the real time operating system. This choice was preferred since our graphical display requirements can only be carried out with the CE environment's GUI kernels.

  13. Optical and opto-acoustic interventional imaging. (United States)

    Sarantopoulos, Athanasios; Beziere, Nicolas; Ntziachristos, Vasilis


    Many clinical interventional procedures, such as surgery or endoscopy, are today still guided by human vision and perception. Human vision however is not sensitive or accurate in detecting a large range of disease biomarkers, for example cellular or molecular processes characteristic of disease. For this reason advanced optical and opto-acoustic (photo-acoustic) methods are considered for enabling a more versatile, sensitive and accurate detection of disease biomarkers and complement human vision in clinical decision making during interventions. Herein, we outline developments in emerging fluorescence and opto-acoustic sensing and imaging techniques that can lead to practical implementations toward improving interventional vision.

  14. Optical metabolic imaging for monitoring tracheal health (United States)

    Sharick, Joe T.; Gil, Daniel A.; Choma, Michael A.; Skala, Melissa C.


    The health of the tracheal mucosa and submucosa is a vital yet poorly understood component of critical care medicine, and a minimally-invasive method is needed to monitor tracheal health in patients. Of particular interest are the ciliated cells of the tracheal epithelium that move mucus away from the lungs and prevent respiratory infection. Optical metabolic imaging (OMI) allows cellular-level measurement of metabolism, and is a compelling method for assessing tracheal health because ciliary motor proteins require ATP to function. In this pilot study, we apply multiphoton imaging of the fluorescence intensities and lifetimes of metabolic co-enzymes NAD(P)H and FAD to the mucosa and submucosa of ex vivo mouse trachea. We demonstrate the feasibility and potential diagnostic utility of these measurements for assessing tracheal health and pathophysiology at the single-cell level.

  15. Optical sensors and their applications for probing biological systems

    DEFF Research Database (Denmark)

    Palanco, Marta Espina

    and mammalian cells. First, we performed Surface Enhanced Raman Spectroscopy (SERS) studies on intact plant materials via using silver plasmonic nanostructures. Our studies showed strong Raman signals which resemble to the presence of typical constituents such as carbohydrates, proteins and lipids of different......There is a great interest in exploring and developing new optical sensitive methodologies for probing complex biological systems. In this project we developed non-invasive and sensitive biosensor strategies for studying physiologically relevant chemical and physical properties of plant...... biological sample to provide a SERS-template where silver nanoparticles can grow, thus providing a new insight into SERS-based sensors for chemically sensing in-situ plant constituents. Optical manipulation techniques have been used to investigate mechanical properties of soft membrane cells, i.e. mammalian...

  16. Absolute instruments and perfect imaging in geometrical optics

    CERN Document Server

    Tyc, Tomas; Sarbort, Martin; Bering, Klaus


    We investigate imaging by spherically symmetric absolute instruments that provide perfect imaging in the sense of geometrical optics. We derive a number of properties of such devices, present a general method for designing them and use this method to propose several new absolute instruments, in particular a lens providing a stigmatic image of an optically homogeneous region and having a moderate refractive index range.

  17. Optical Coherence Tomography in Cancer Imaging (United States)

    Nam, Ahhyun Stephanie; Vakoc, Benjamin; Blauvelt, David; Chico-Calero, Isabel

    Investigations into the biology of cancer and novel cancer therapies rely on preclinical mouse models and traditional histological endpoints. Drawbacks of this approach include a limit in the number of time points for evaluation and an increased number of animals per study. This has motivated the use of intravital microscopy, which can provide longitudinal imaging of critical tumor parameters. Here, the capabilities of OCT as an intravital microscopy of the tumor microenvironment are summarized, and the state of OCT adoption into cancer research is summarized.

  18. Finite-difference time-domain-based optical microscopy simulation of dispersive media facilitates the development of optical imaging techniques (United States)

    Zhang, Di; Capoglu, Ilker; Li, Yue; Cherkezyan, Lusik; Chandler, John; Spicer, Graham; Subramanian, Hariharan; Taflove, Allen; Backman, Vadim


    Combining finite-difference time-domain (FDTD) methods and modeling of optical microscopy modalities, we previously developed an open-source software package called Angora, which is essentially a "microscope in a computer." However, the samples being simulated were limited to nondispersive media. Since media dispersions are common in biological samples (such as cells with staining and metallic biomarkers), we have further developed a module in Angora to simulate samples having complicated dispersion properties, thereby allowing the synthesis of microscope images of most biological samples. We first describe a method to integrate media dispersion into FDTD, and we validate the corresponding Angora dispersion module by applying Mie theory, as well as by experimentally imaging gold microspheres. Then, we demonstrate how Angora can facilitate the development of optical imaging techniques with a case study.

  19. Image-based adaptive optics for in vivo imaging in the hippocampus (United States)

    Champelovier, D.; Teixeira, J.; Conan, J.-M.; Balla, N.; Mugnier, L. M.; Tressard, T.; Reichinnek, S.; Meimon, S.; Cossart, R.; Rigneault, H.; Monneret, S.; Malvache, A.


    Adaptive optics is a promising technique for the improvement of microscopy in tissues. A large palette of indirect and direct wavefront sensing methods has been proposed for in vivo imaging in experimental animal models. Application of most of these methods to complex samples suffers from either intrinsic and/or practical difficulties. Here we show a theoretically optimized wavefront correction method for inhomogeneously labeled biological samples. We demonstrate its performance at a depth of 200 μm in brain tissue within a sparsely labeled region such as the pyramidal cell layer of the hippocampus, with cells expressing GCamP6. This method is designed to be sample-independent thanks to an automatic axial locking on objects of interest through the use of an image-based metric that we designed. Using this method, we show an increase of in vivo imaging quality in the hippocampus. PMID:28220868

  20. Image-based adaptive optics for in vivo imaging in the hippocampus (United States)

    Champelovier, D.; Teixeira, J.; Conan, J.-M.; Balla, N.; Mugnier, L. M.; Tressard, T.; Reichinnek, S.; Meimon, S.; Cossart, R.; Rigneault, H.; Monneret, S.; Malvache, A.


    Adaptive optics is a promising technique for the improvement of microscopy in tissues. A large palette of indirect and direct wavefront sensing methods has been proposed for in vivo imaging in experimental animal models. Application of most of these methods to complex samples suffers from either intrinsic and/or practical difficulties. Here we show a theoretically optimized wavefront correction method for inhomogeneously labeled biological samples. We demonstrate its performance at a depth of 200 μm in brain tissue within a sparsely labeled region such as the pyramidal cell layer of the hippocampus, with cells expressing GCamP6. This method is designed to be sample-independent thanks to an automatic axial locking on objects of interest through the use of an image-based metric that we designed. Using this method, we show an increase of in vivo imaging quality in the hippocampus.

  1. Optical cryptography topology based on a three-dimensional particle-like distribution and diffractive imaging. (United States)

    Chen, Wen; Chen, Xudong


    In recent years, coherent diffractive imaging has been considered as a promising alternative for information retrieval instead of conventional interference methods. Coherent diffractive imaging using the X-ray light source has opened up a new research perspective for the measurement of non-crystalline and biological specimens, and can achieve unprecedentedly high resolutions. In this paper, we show how a three-dimensional (3D) particle-like distribution and coherent diffractive imaging can be applied for a study of optical cryptography. An optical multiple-random-phase-mask encoding approach is used, and the plaintext is considered as a series of particles distributed in a 3D space. A topology concept is also introduced into the proposed optical cryptosystem. During image decryption, a retrieval algorithm is developed to extract the plaintext from the ciphertexts. In addition, security and advantages of the proposed optical cryptography topology are also analyzed.

  2. Picosecond optical MCPI-based imagers (United States)

    Buckles, Robert A.; Guyton, Robert L.; Ross, Patrick W.


    We present the desired performance specifications for an advanced optical imager, which borrows practical concepts in high-speed microchannel plate (MCP) intensified x-ray stripline imagers and time-dilation techniques. With a four-fold speed improvement in state-of-the-art high-voltage impulse drivers, and novel atomic-layer deposition MCPs, we tender a design capable of 5 ps optical gating without the use of magnetic field confinement of the photoelectrons. We analyze the electron dispersion effects in the MCP and their implications for gating pulses shorter than the MCP transit time. We present a wideband design printed-circuit version of the Series Transmission Line Transformer (STLT) that makes use of 50-ohm coaxial 1.0 mm (110 GHz) and 1.85 mm (65 GHz) hermetically sealed vacuum feedthroughs and low-dispersion Teflon/Kapton circuit materials without the use of any vias. The STLT matches impedance at all interfaces with a 16:1 impedance (4:1 voltage) reduction, and delivers a dispersion-limited sharp impulse to the MCP strip. A comparison of microstrip design calculations is given, showing variances between method of moments, empirical codes, and finite element methods for broad, low-impedance traces. Prototype performance measurements are forthcoming.

  3. Optical image processing by using a photorefractive spatial soliton waveguide (United States)

    Liang, Bao-Lai; Wang, Ying; Zhang, Su-Heng; Guo, Qing-Lin; Wang, Shu-Fang; Fu, Guang-Sheng; Simmonds, Paul J.; Wang, Zhao-Qi


    By combining the photorefractive spatial soliton waveguide of a Ce:SBN crystal with a coherent 4-f system we are able to manipulate the spatial frequencies of an input optical image to perform edge-enhancement and direct component enhancement operations. Theoretical analysis of this optical image processor is presented to interpret the experimental observations. This work provides an approach for optical image processing by using photorefractive spatial solitons.

  4. Optical Image Classification Using Optical/digital Hybrid Image Processing Systems. (United States)

    Li, Xiaoyang


    Offering parallel and real-time operations, optical image classification is becoming a general technique in the solution of real-life image classification problems. This thesis investigates several algorithms for optical realization. Compared to other statistical pattern recognition algorithms, the Kittler-Young transform can provide more discriminative feature spaces for image classification. We shall apply the Kittler-Young transform to image classification and implement it on optical systems. A feature selection criterion is designed for the application of the Kittler -Young transform to image classification. The realizations of the Kittler-Young transform on both a joint transform correlator and a matrix multiplier are successively conducted. Experiments of applying this technique to two-category and three-category problems are demonstrated. To combine the advantages of the statistical pattern recognition algorithms and the neural network models, processes using the two methods are studied. The Karhunen-Loeve Hopfield model is developed for image classification. This model has significant improvement in the system capacity and the capability of using image structures for more discriminative classification processes. As another such hybrid process, we propose the feature extraction perceptron. The application of feature extraction techniques to the perceptron shortens its learning time. An improved activation function of neurons (dynamic activation function), its design and updating rule for fast learning process and high space-bandwidth product image classification are also proposed. We have shortened by two-thirds the learning time on the feature extraction perceptron as compared with the original perceptron. By using this architecture, we have shown that the classification performs better than both the Kittler-Young transform and the original perceptron.

  5. Perfect optical vortex enhanced surface plasmon excitation for plasmonic structured illumination microscopy imaging (United States)

    Zhang, Chonglei; Min, Changjun; Du, Luping; Yuan, X.-C.


    We propose an all-optical technique for plasmonic structured illumination microscopy (PSIM) with perfect optical vortex (POV). POV can improve the efficiency of the excitation of surface plasma and reduce the background noise of the excited fluorescence. The plasmonic standing wave patterns are excited by POV with fractional topological charges for accurate phase shift of {-2π/3, 0, and 2π/3}. The imaging resolution of less than 200 nm was produced. This PSIM technique is expected to be used as a wide field, super resolution imaging technique in dynamic biological imaging.

  6. An integral design strategy combining optical system and image processing to obtain high resolution images (United States)

    Wang, Jiaoyang; Wang, Lin; Yang, Ying; Gong, Rui; Shao, Xiaopeng; Liang, Chao; Xu, Jun


    In this paper, an integral design that combines optical system with image processing is introduced to obtain high resolution images, and the performance is evaluated and demonstrated. Traditional imaging methods often separate the two technical procedures of optical system design and imaging processing, resulting in the failures in efficient cooperation between the optical and digital elements. Therefore, an innovative approach is presented to combine the merit function during optical design together with the constraint conditions of image processing algorithms. Specifically, an optical imaging system with low resolution is designed to collect the image signals which are indispensable for imaging processing, while the ultimate goal is to obtain high resolution images from the final system. In order to optimize the global performance, the optimization function of ZEMAX software is utilized and the number of optimization cycles is controlled. Then Wiener filter algorithm is adopted to process the image simulation and mean squared error (MSE) is taken as evaluation criterion. The results show that, although the optical figures of merit for the optical imaging systems is not the best, it can provide image signals that are more suitable for image processing. In conclusion. The integral design of optical system and image processing can search out the overall optimal solution which is missed by the traditional design methods. Especially, when designing some complex optical system, this integral design strategy has obvious advantages to simplify structure and reduce cost, as well as to gain high resolution images simultaneously, which has a promising perspective of industrial application.

  7. Biological effects of exposure to magnetic resonance imaging: an overview


    Formica Domenico; Silvestri Sergio


    Abstract The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to a...

  8. Near-field scanning optical microscopy in cell biology and cytogenetics. (United States)

    Hausmann, Michael; Perner, Birgit; Rapp, Alexander; Wollweber, Leo; Scherthan, Harry; Greulich, Karl-Otto


    Light microscopy has proven to be one of the most versatile analytical tools in cell biology and cytogenetics. The growing spectrum of scientific knowledge demands a continuous improvement of the optical resolution of the instruments. In far-field light microscopy, the attainable resolution is dictated by the limit of diffraction, which, in practice, is about 250 nm for high-numerical-aperture objective lenses. Near-field scanning optical microscopy (NSOM) was the first technique that has overcome this limit up to about one order of magnitude. Typically, the resolution range below 100 nm is accessed for biological applications. Using appropriately designed scanning probes allows for obtaining an extremely small near-field light excitation volume (some tens of nanometers in diameter). Because of the reduction of background illumination, high contrast imaging becomes feasible for light transmission and fluorescence microscopy. The height of the scanning probe is controlled by atomic force interactions between the specimen surface and the probe tip. The control signal can be used for the production of a topographic (nonoptical) image that can be acquired simultaneously. In this chapter, the principle of NSOM is described with respect to biological applications. A brief overview of some requirements in biology and applications described in the literature are given. Practical advice is focused on instruments with aperture-type illumination probes. Preparation protocols focussing on NSOM of cell surfaces and chromosomes are presented.

  9. Molecular imaging by optically-detected electron spin resonance of nitrogen-vacancies in nanodiamond

    CERN Document Server

    Hegyi, Alex


    Molecular imaging refers to a class of noninvasive biomedical imaging techniques with the sensitivity and specificity to image biochemical variations in-vivo. An ideal molecular imaging technique visualizes a biochemical target according to a range of criteria, including high spatial and temporal resolution, high contrast relative to non-targeted tissues, depth-independent penetration into tissue, lack of harm to the organism under study, and low cost. Because no existing molecular imaging modality is ideal for all purposes, new imaging approaches are needed. Here we demonstrate a novel molecular imaging approach, called nanodiamond imaging, that uses nanodiamonds containing nitrogen-vacancy (NV) color centers as an imaging agent, and image nanodiamond targets in pieces of chicken breast. Nanodiamonds can be tagged with biologically active molecules so they bind to specific receptors; their distribution can then be quantified in-vivo via optically-detected magnetic resonance of the NVs. In effect, we are demo...

  10. Computational high-resolution optical imaging of the living human retina (United States)

    Shemonski, Nathan D.; South, Fredrick A.; Liu, Yuan-Zhi; Adie, Steven G.; Scott Carney, P.; Boppart, Stephen A.


    High-resolution in vivo imaging is of great importance for the fields of biology and medicine. The introduction of hardware-based adaptive optics (HAO) has pushed the limits of optical imaging, enabling high-resolution near diffraction-limited imaging of previously unresolvable structures. In ophthalmology, when combined with optical coherence tomography, HAO has enabled a detailed three-dimensional visualization of photoreceptor distributions and individual nerve fibre bundles in the living human retina. However, the introduction of HAO hardware and supporting software adds considerable complexity and cost to an imaging system, limiting the number of researchers and medical professionals who could benefit from the technology. Here we demonstrate a fully automated computational approach that enables high-resolution in vivo ophthalmic imaging without the need for HAO. The results demonstrate that computational methods in coherent microscopy are applicable in highly dynamic living systems.

  11. Anterior Eye Imaging with Optical Coherence Tomography (United States)

    Huang, David; Li, Yan; Tang, Maolong

    The development of corneal and anterior segment optical coherence tomography (OCT) technology has advanced rapidly in recently years. The scan geometry and imaging wavelength are both important choices to make in designing anterior segment OCT systems. Rectangular scan geometry offers the least image distortion and is now used in most anterior OCT systems. The wavelength of OCT light source affects resolution and penetration. An optimal choice of the OCT imaging wavelength (840, 1,050, or 1,310 nm) depends on the application of interest. Newer generation Fourier-domain OCT technology can provide scan speed 100-1000 times faster than the time-domain technology. Various commercial anterior OCT systems are available on the market. A wide spectrum of diagnostic and surgical applications using anterior segment OCT had been investigated, including mapping of corneal and epithelial thicknesses, keratoconus screening, measuring corneal refractive power, corneal surgery planning and evaluation in LASIK, intracorneal ring implantation, assessment of angle closure glaucoma, anterior chamber biometry and intraocular lens implants, intraocular lens power calculation, and eye bank donor cornea screening.

  12. Probing bacterial cell biology using image cytometry. (United States)

    Cass, Julie A; Stylianidou, Stella; Kuwada, Nathan J; Traxler, Beth; Wiggins, Paul A


    Advances in automated fluorescence microscopy have made snapshot and time-lapse imaging of bacterial cells commonplace, yet fundamental challenges remain in analysis. The vast quantity of data collected in high-throughput experiments requires a fast and reliable automated method to analyze fluorescence intensity and localization, cell morphology and proliferation as well as other descriptors. Inspired by effective yet tractable methods of population-level analysis using flow cytometry, we have developed a framework and tools for facilitating analogous analyses in image cytometry. These tools can both visualize and gate (generate subpopulations) more than 70 cell descriptors, including cell size, age and fluorescence. The method is well suited to multi-well imaging, analysis of bacterial cultures with high cell density (thousands of cells per frame) and complete cell cycle imaging. We give a brief description of the analysis of four distinct applications to emphasize the broad applicability of the tool.

  13. Reconstruction of Optical Thickness from Hoffman Modulation Contrast Images

    DEFF Research Database (Denmark)

    Olsen, Niels Holm; Sporring, Jon; Nielsen, Mads;


    Hoffman microscopy imaging systems are part of numerous fertility clinics world-wide. We discuss the physics of the Hoffman imaging system from optical thickness to image intensity, implement a simple, yet fast, reconstruction algorithm using Fast Fourier Transformation and discuss the usability...... of the method on a number of cells from a human embryo. Novelty is identifying the non-linearity of a typical Hoffman imaging system, and the application of Fourier Transformation to reconstruct the optical thickness....

  14. THz imaging of majolica tiles and biological attached marble fragments (United States)

    Catapano, Ilaria; Soldovieri, Francesco


    Devices exploiting waves in the frequency range from 0.1 THz to 10 THz (corresponding to a free-space wavelength ranging from 30 μm to 3 mm) deserve attention as diagnostic technologies for cultural heritage. THz waves are, indeed, non-ionizing radiations capable of penetrating into non-metallic materials, which are opaque to both visible and infrared waves, without implying long term risks to the molecular stability of the exposed objects and humans. Moreover, THz surveys involve low poewr probing waves, are performed without contact with the object and, thanks to the recent developments, which have allowed the commercialization of compact, flexible and portable systems, maybe performed in loco (i.e. in the place where the artworks are usually located). On the other hand, THz devices can be considered as the youngest among the sensing and imaging electromagnetic techniques and their actual potentialities in terms of characterization of artworks is an ongoing research activity. As a contribution within this context, we have performed time of flight THz imaging [1,2] on ceramic and marble objects. In particular, we surveyed majolica tiles produced by Neapolitan ceramists in the 18th and 19th centuries with the aim to gather information on their structure, constructive technique and conservation state. Moreover, we investigated a Marmo di Candoglia fragment in order to characterize the biological attach affecting it. All the surveys were carried out by using the Fiber-Coupled Terahertz Time Domain System (FICO) developed by Z-Omega and available at the Institute of Electromagnetic Sensing of the Environment (IREA). This system is equipped with fiber optic coupled transmitting and receiving probes and with an automatic positioning system enabling to scan a 150 mm x 150 mm area under a reflection measurement configuration. Based on the obtained results we can state that the use of THz waves allows: - the reconstruction of the object topography; - the geometrical

  15. Advances in the Simultaneous Multiple Surface optical design method for imaging and non-imaging applications


    Wang, Lin


    Classical imaging optics has been developed over centuries in many areas, such as its paraxial imaging theory and practical design methods like multi-parametric optimization techniques. Although these imaging optical design methods can provide elegant solutions to many traditional optical problems, there are more and more new design problems, like solar concentrator, illumination system, ultra-compact camera, etc., that require maximum energy transfer efficiency, or ultra-compact optical stru...

  16. Hybrid micro-/nanogels for optical sensing and intracellular imaging

    Directory of Open Access Journals (Sweden)

    Shuiqin Zhou


    Full Text Available Hybrid micro-/nanogels are playing an increasing important part in a diverse range of applications, due to their tunable dimensions, large surface area, stable interior network structure, and a very short response time. We review recent advances and challenges in the developments of hybrid micro-/nanogels toward applications for optical sensing of pH, temperature, glucose, ions, and other species as well as for intracellular imaging. Due to their unique advantages, hybrid micro-/nanogels as optical probes are attracting substantial interests for continuous monitoring of chemical parameters in complex samples such as blood and bioreactor fluids, in chemical research and industry, and in food quality control. In particular, their intracellular probing ability enables the monitoring of the biochemistry and biophysics of live cells over time and space, thus contributing to the explanation of intricate biological processes and the development of novel diagnoses. Unlike most other probes, hybrid micro-/nanogels could also combine other multiple functions into a single probe. The rational design of hybrid micro-/nanogels will not only improve the probing applications as desirable, but also implement their applications in new arenas. With ongoing rapid advances in bionanotechnology, the well-designed hybrid micro-/nanogel probes will be able to provide simultaneous sensing, imaging diagnosis, and therapy toward clinical applications.

  17. Optical coherence tomography: imaging architect for dermal microdialysis in psoriasis (United States)

    O'Connell, M.-L.; O'Connor, W.; Ramsay, B.; Guihen, E.; Ho, W. L.; Leahy, M. J.


    Optical coherence tomography (OCT) has been used as part of a ground breaking translational study to shed some light on one of the worlds most prevalent autoimmune diseases; psoriasis. The work successfully integrates the fields of optical imaging, biochemistry and dermatology in conducting a dermal microdialysis (DMD) trial for quantitative histamine assessment amongst a group of psoriasis sufferers. The DMD process involves temporary insertion of microscopic hollow tubes into a layer of skin to measure the levels of histamine and other important biological molecules in psoriasis. For comparison purposes, DMD catheters were implanted into healthy, peri-lesional and lesional skin regions. The catheters' entry and exit points and their precise locations in the epidermal layer of the skin were confirmed using OCT thus obtaining high resolution, wide-field images of the affected skin as well as catheter placement whilst local microdialysis enabled a tissue chemistry profile to be obtained from these three skin regions including histamine, a local immune system activator known to contribute towards itch and inflammation. Together these tools offer a synergistic approach in the clinical assessment of the disease. In addition, OCT delivered a non-invasive and rapid method for analyzing the affected skin architecture.

  18. Can preoperative MR imaging predict optic nerve invasion of retinoblastoma?

    Energy Technology Data Exchange (ETDEWEB)

    Song, Kyoung Doo, E-mail: [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Eo, Hong, E-mail: [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Kim, Ji Hye, E-mail: [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Yoo, So-Young, E-mail: [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of); Jeon, Tae Yeon, E-mail: [Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Ilwon-Dong, Kangnam-Ku, Seoul 135-710 (Korea, Republic of)


    Purpose: To evaluate the accuracy of pre-operative MRI for the detection of optic nerve invasion in retinoblastoma. Materials and methods: Institutional review board approval and informed consent were waived for this retrospective study. A total of 41 patients were included. Inclusion criteria were histologically proven retinoblastoma, availability of diagnostic-quality preoperative MR images acquired during the 4 weeks before surgery, unilateral retinoblastoma, and normal-sized optic nerve. Two radiologists retrospectively reviewed the MR images independently. Five imaging findings (diffuse mild optic nerve enhancement, focal strong optic nerve enhancement, optic sheath enhancement, tumor location, and tumor size) were evaluated against optic nerve invasion of retinoblastoma. The predictive performance of all MR imaging findings for optic nerve invasion was also evaluated by the receiver operating characteristic curve analysis. Results: Optic nerve invasion was histopathologically confirmed in 24% of study population (10/41). The differences in diffuse mild enhancement, focal strong enhancement, optic sheath enhancement, and tumor location between patients with optic nerve invasion and patients without optic nerve invasion were not significant. Tumor sizes were 16.1 mm (SD: 2.2 mm) and 14.9 mm (SD: 3.6 mm) in patients with and without optic nerve involvement, respectively (P = 0.444). P-Values from binary logistic regression indicated that all five imaging findings were not significant predictors of tumor invasion of optic nerve. The AUC values of all MR imaging findings for the prediction of optic nerve invasion were 0.689 (95% confidence interval: 0.499–0.879) and 0.653 (95% confidence interval: 0.445–0.861) for observer 1 and observer 2, respectively. Conclusion: Findings of MRI in patients with normal-sized optic nerves have limited usefulness in preoperatively predicting the presence of optic nerve invasion in retinoblastoma.

  19. Joint Applied Optics and Chinese Optics Letters feature introduction: digital holography and three-dimensional imaging. (United States)

    Poon, Ting-Chung


    This feature issue serves as a pilot issue promoting the joint issue of Applied Optics and Chinese Optics Letters. It focuses upon topics of current relevance to the community working in the area of digital holography and 3-D imaging.

  20. Polarization sensitive spectroscopic optical coherence tomography for multimodal imaging (United States)

    Strąkowski, Marcin R.; Kraszewski, Maciej; Strąkowska, Paulina; Trojanowski, Michał


    Optical coherence tomography (OCT) is a non-invasive method for 3D and cross-sectional imaging of biological and non-biological objects. The OCT measurements are provided in non-contact and absolutely safe way for the tested sample. Nowadays, the OCT is widely applied in medical diagnosis especially in ophthalmology, as well as dermatology, oncology and many more. Despite of great progress in OCT measurements there are still a vast number of issues like tissue recognition or imaging contrast enhancement that have not been solved yet. Here we are going to present the polarization sensitive spectroscopic OCT system (PS-SOCT). The PS-SOCT combines the polarization sensitive analysis with time-frequency analysis. Unlike standard polarization sensitive OCT the PS-SOCT delivers spectral information about measured quantities e.g. tested object birefringence changes over the light spectra. This solution overcomes the limits of polarization sensitive analysis applied in standard PS-OCT. Based on spectral data obtained from PS-SOCT the exact value of birefringence can be calculated even for the objects that provide higher order of retardation. In this contribution the benefits of using the combination of time-frequency and polarization sensitive analysis are being expressed. Moreover, the PS-SOCT system features, as well as OCT measurement examples are presented.

  1. Novel spirometry based on optical surface imaging

    Energy Technology Data Exchange (ETDEWEB)

    Li, Guang, E-mail:; Huang, Hailiang; Li, Diana G.; Chen, Qing; Gaebler, Carl P.; Mechalakos, James [Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Wei, Jie [Department of Computer Science, City College of New York, New York, New York 10031 (United States); Sullivan, James [Pulmonary Laboratories, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States); Zatcky, Joan; Rimner, Andreas [Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, New York 10065 (United States)


    Purpose: To evaluate the feasibility of using optical surface imaging (OSI) to measure the dynamic tidal volume (TV) of the human torso during free breathing. Methods: We performed experiments to measure volume or volume change in geometric and deformable phantoms as well as human subjects using OSI. To assess the accuracy of OSI in volume determination, we performed experiments using five geometric phantoms and two deformable body phantoms and compared the values with those derived from geometric calculations and computed tomography (CT) measurements, respectively. To apply this technique to human subjects, an institutional review board protocol was established and three healthy volunteers were studied. In the human experiment, a high-speed image capture mode of OSI was applied to acquire torso images at 4–5 frames per second, which was synchronized with conventional spirometric measurements at 5 Hz. An in-house MATLAB program was developed to interactively define the volume of interest (VOI), separate the thorax and abdomen, and automatically calculate the thoracic and abdominal volumes within the VOIs. The torso volume change (TV C = ΔV{sub torso} = ΔV{sub thorax} + ΔV{sub abdomen}) was automatically calculated using full-exhalation phase as the reference. The volumetric breathing pattern (BP{sub v} = ΔV{sub thorax}/ΔV{sub torso}) quantifying thoracic and abdominal volume variations was also calculated. Under quiet breathing, TVC should equal the tidal volume measured concurrently by a spirometer with a conversion factor (1.08) accounting for internal and external differences of temperature and moisture. Another MATLAB program was implemented to control the conventional spirometer that was used as the standard. Results: The volumes measured from the OSI imaging of geometric phantoms agreed with the calculated volumes with a discrepancy of 0.0% ± 1.6% (range −1.9% to 2.5%). In measurements from the deformable torso/thorax phantoms, the volume

  2. Imaging of membrane proteins using antenna-based optical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hoeppener, Christiane; Novotny, Lukas [Institute of Optics and Department of Biomedical Engineering, University of Rochester, Rochester, NY 14627 (United States)], E-mail:


    The localization and identification of individual proteins is of key importance for the understanding of biological processes on the molecular scale. Here, we demonstrate near-field fluorescence imaging of single proteins in their native cell membrane. Incident laser radiation is localized and enhanced with an optical antenna in the form of a spherical gold particle attached to a pointed dielectric tip. Individual proteins can be identified with a diffraction-unlimited spatial resolution of {approx}50 nm. Besides determining the concentration and distribution of specific membrane proteins, this approach makes it possible to study the colocalization of different membrane proteins. Moreover, it enables a simultaneous recording of the membrane topology. Protein distributions can be correlated with the local membrane topology, thereby providing important information on the chemical and structural organization of cellular membranes.

  3. Wide-field optical sectioning for live-tissue imaging by plane-projection multiphoton microscopy (United States)

    Yu, Jiun-Yann; Kuo, Chun-Hung; Holland, Daniel B.; Chen, Yenyu; Ouyang, Mingxing; Blake, Geoffrey A.; Zadoyan, Ruben; Guo, Chin-Lin


    Optical sectioning provides three-dimensional (3D) information in biological tissues. However, most imaging techniques implemented with optical sectioning are either slow or deleterious to live tissues. Here, we present a simple design for wide-field multiphoton microscopy, which provides optical sectioning at a reasonable frame rate and with a biocompatible laser dosage. The underlying mechanism of optical sectioning is diffuser-based temporal focusing. Axial resolution comparable to confocal microscopy is theoretically derived and experimentally demonstrated. To achieve a reasonable frame rate without increasing the laser power, a low-repetition-rate ultrafast laser amplifier was used in our setup. A frame rate comparable to that of epifluorescence microscopy was demonstrated in the 3D imaging of fluorescent protein expressed in live epithelial cell clusters. In this report, our design displays the potential to be widely used for video-rate live-tissue and embryo imaging with axial resolution comparable to laser scanning microscopy.

  4. Embryonic stem cell biology: insights from molecular imaging. (United States)

    Sallam, Karim; Wu, Joseph C


    Embryonic stem (ES) cells have therapeutic potential in disorders of cellular loss such as myocardial infarction, type I diabetes and neurodegenerative disorders. ES cell biology in living subjects was largely poorly understood until incorporation of molecular imaging into the field. Reporter gene imaging works by integrating a reporter gene into ES cells and using a reporter probe to induce a signal detectable by normal imaging modalities. Reporter gene imaging allows for longitudinal tracking of ES cells within the same host for a prolonged period of time. This has advantages over postmortem immunohistochemistry and traditional imaging modalities. The advantages include expression of reporter gene is limited to viable cells, expression is conserved between generations of dividing cells, and expression can be linked to a specific population of cells. These advantages were especially useful in studying a dynamic cell population such as ES cells and proved useful in elucidating the biology of ES cells. Reporter gene imaging identified poor integration of differentiated ES cells transplanted into host tissue as well as delayed donor cell death as reasons for poor long-term survival in vivo. This imaging technology also confirmed that ES cells indeed have immunogenic properties that factor into cell survival and differentiation. Finally, reporter gene imaging improved our understanding of the neoplastic risk of undifferentiated ES cells in forming teratomas. Despite such advances, much remains to be understood about ES cell biology to translate this technology to the bedside, and reporter gene imaging will certainly play a key role in formulating this understanding.

  5. Novel optical scanning cryptography using Fresnel telescope imaging. (United States)

    Yan, Aimin; Sun, Jianfeng; Hu, Zhijuan; Zhang, Jingtao; Liu, Liren


    We propose a new method called modified optical scanning cryptography using Fresnel telescope imaging technique for encryption and decryption of remote objects. An image or object can be optically encrypted on the fly by Fresnel telescope scanning system together with an encryption key. For image decryption, the encrypted signals are received and processed with an optical coherent heterodyne detection system. The proposed method has strong performance through use of secure Fresnel telescope scanning with orthogonal polarized beams and efficient all-optical information processing. The validity of the proposed method is demonstrated by numerical simulations and experimental results.

  6. Optical force on diseased blood cells: Towards the optical sorting of biological matter

    KAUST Repository

    Gongora, J. S. Totero


    By employing a series of massively parallel ab-initio simulations, we study how optical forces act on biological matter subject to morphological disease. As a representative case study, we here consider the case of Plasmodium falciparum on red blood cells (RBC) illuminated by a monochromatic plane wave. Realistic parameters for the geometry and the refractive index are then taken from published experiments. In our theoretical campaign, we study the dependence of the optical force on the disease stage for different incident wavelengths. We show that optical forces change significantly with the disease, with amplitude variation in the hundreds of pN range. Our results open up new avenues for the design of new optical systems for the treatment of human disease. © 2015 Elsevier Ltd.

  7. Optical force on diseased blood cells: towards the optical sorting of biological matter

    CERN Document Server

    Gongora, Juan Sebastian Totero


    By employing a series of massively parallel ab-initio simulations, we study how optical forces act on biological matter subject to morphological disease. As a representative case study, we here consider the case of Plasmodium Falciparum on red blood cells (RBC) illuminated by a monochromatic plane wave. Realistic parameters for the geometry and the refractive index are then taken from published experiments. In our theoretical campaign, we study the dependence of the optical force on the disease stage for different incident wavelengths. We show that optical forces change significantly with the disease, with amplitude variation in the hundreds of pN range. Our results open up new avenues for the design of new optical systems for the treatment of human disease.

  8. Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging of Sentinel Lymph Node and Tumor (United States)

    Qin, Zhengtao

    Molecular imaging is visualizations and measurements of in vivo biological processes at the molecular or cellular level using specific imaging probes. As an emerging technology, biocompatible macromolecular or nanoparticle based targeted imaging probes have gained increasing popularities. Those complexes consist of a carrier, an imaging reporter, and a targeting ligand. The active targeting ability dramatically increases the specificity. And the multivalency effect may further reduce the dose while providing a decent signal. In this thesis, sentinel lymph node (SLN) mapping and cancer imaging are two research topics. The focus is to develop molecular imaging probes with high specificity and sensitivity, for Positron Emission Tomography (PET) and optical imaging. The objective of this thesis is to explore dextran radiopharmaceuticals and porous silicon nanoparticles based molecular imaging agents. Dextran polymers are excellent carriers to deliver imaging reporters or therapeutic agents due to its well established safety profile and oligosaccharide conjugation chemistry. There is also a wide selection of dextran polymers with different lengths. On the other hand, Silicon nanoparticles represent another class of biodegradable materials for imaging and drug delivery. The success in fluorescence lifetime imaging and enhancements of the immune activation potency was briefly discussed. Chapter 1 begins with an overview on current molecular imaging techniques and imaging probes. Chapter 2 presents a near-IR dye conjugated probe, IRDye 800CW-tilmanocept. Fluorophore density was optimized to generate the maximum brightness. It was labeled with 68Ga and 99mTc and in vivo SLN mapping was successfully performed in different animals, such as mice, rabbits, dogs and pigs. With 99mTc labeled IRDye 800CW-tilmanocept, chapter 3 introduces a two-day imaging protocol with a hand-held imager. Chapter 4 proposed a method to dual radiolabel the IRDye 800CW-tilmanocept with both 68Ga and

  9. Document Indexing for Image-Based Optical Information Systems. (United States)

    Thiel, Thomas J.; And Others


    Discussion of image-based information retrieval systems focuses on indexing. Highlights include computerized information retrieval; multimedia optical systems; optical mass storage and personal computers; and a case study that describes an optical disk system which was developed to preserve, access, and disseminate military documents. (19…

  10. Pattern recognition software and techniques for biological image analysis.

    Directory of Open Access Journals (Sweden)

    Lior Shamir

    Full Text Available The increasing prevalence of automated image acquisition systems is enabling new types of microscopy experiments that generate large image datasets. However, there is a perceived lack of robust image analysis systems required to process these diverse datasets. Most automated image analysis systems are tailored for specific types of microscopy, contrast methods, probes, and even cell types. This imposes significant constraints on experimental design, limiting their application to the narrow set of imaging methods for which they were designed. One of the approaches to address these limitations is pattern recognition, which was originally developed for remote sensing, and is increasingly being applied to the biology domain. This approach relies on training a computer to recognize patterns in images rather than developing algorithms or tuning parameters for specific image processing tasks. The generality of this approach promises to enable data mining in extensive image repositories, and provide objective and quantitative imaging assays for routine use. Here, we provide a brief overview of the technologies behind pattern recognition and its use in computer vision for biological and biomedical imaging. We list available software tools that can be used by biologists and suggest practical experimental considerations to make the best use of pattern recognition techniques for imaging assays.

  11. Pattern recognition software and techniques for biological image analysis. (United States)

    Shamir, Lior; Delaney, John D; Orlov, Nikita; Eckley, D Mark; Goldberg, Ilya G


    The increasing prevalence of automated image acquisition systems is enabling new types of microscopy experiments that generate large image datasets. However, there is a perceived lack of robust image analysis systems required to process these diverse datasets. Most automated image analysis systems are tailored for specific types of microscopy, contrast methods, probes, and even cell types. This imposes significant constraints on experimental design, limiting their application to the narrow set of imaging methods for which they were designed. One of the approaches to address these limitations is pattern recognition, which was originally developed for remote sensing, and is increasingly being applied to the biology domain. This approach relies on training a computer to recognize patterns in images rather than developing algorithms or tuning parameters for specific image processing tasks. The generality of this approach promises to enable data mining in extensive image repositories, and provide objective and quantitative imaging assays for routine use. Here, we provide a brief overview of the technologies behind pattern recognition and its use in computer vision for biological and biomedical imaging. We list available software tools that can be used by biologists and suggest practical experimental considerations to make the best use of pattern recognition techniques for imaging assays.

  12. Adaptive optics and phase diversity imaging for responsive space applications.

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Mark William; Wick, David Victor


    The combination of phase diversity and adaptive optics offers great flexibility. Phase diverse images can be used to diagnose aberrations and then provide feedback control to the optics to correct the aberrations. Alternatively, phase diversity can be used to partially compensate for aberrations during post-detection image processing. The adaptive optic can produce simple defocus or more complex types of phase diversity. This report presents an analysis, based on numerical simulations, of the efficiency of different modes of phase diversity with respect to compensating for specific aberrations during post-processing. It also comments on the efficiency of post-processing versus direct aberration correction. The construction of a bench top optical system that uses a membrane mirror as an active optic is described. The results of characterization tests performed on the bench top optical system are presented. The work described in this report was conducted to explore the use of adaptive optics and phase diversity imaging for responsive space applications.

  13. Single beam optical trapping integrated in a confocal microscope for biological applications. (United States)

    Visscher, K; Brakenhoff, G J


    Confocal microscopy is very useful in biology because of its three dimensional imaging capacities and has proven to be an excellent tool to study the 3D organization of, for instance, cell structures. This property of confocal microscopy makes it also very suitable for observation during guidance of the three dimensional manipulation of single cells or cell elements. Therefore we decided to integrate a confocal microscope and a single beam optical manipulator into a single instrument. The advantage of optical manipulation over mechanical techniques is that it is non-invasive and therefore may be applied on living (micro-) organisms and cells. The creation of an effective single beam optical trap requires the use of a high numerical aperture (N.A.) objective to focus the laser beam. In this paper we briefly discuss the vertical or axial force exerted on a sphere in a single beam trap. The axial force on a sphere placed on the optical axis, caused by reflection and refraction, is calculated applying a electromagnetic vector diffraction theory to determine the field distribution in the focal region. One of the results is that the particle also experiences a vertical trapping force towards the focusing lens when it is in the strongly convergent part of the field in addition to the known negative signed trapping force in the divergent part of the field. Further we describe an instrumental approach to realize optical trapping in which the optical trap position is controlled by moving the focusing objective only.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Handbook of 3D machine vision optical metrology and imaging

    CERN Document Server

    Zhang, Song


    With the ongoing release of 3D movies and the emergence of 3D TVs, 3D imaging technologies have penetrated our daily lives. Yet choosing from the numerous 3D vision methods available can be frustrating for scientists and engineers, especially without a comprehensive resource to consult. Filling this gap, Handbook of 3D Machine Vision: Optical Metrology and Imaging gives an extensive, in-depth look at the most popular 3D imaging techniques. It focuses on noninvasive, noncontact optical methods (optical metrology and imaging). The handbook begins with the well-studied method of stereo vision and

  15. A compact gamma camera for biological imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, E L; Cella, J; Majewski, S; Popov, V; Qian, Jianguo; Saha, M S; Smith, M F; Weisenberger, A G; Welsh, R E


    A compact detector, sized particularly for imaging a mouse, is described. The active area of the detector is approximately 46 mm; spl times/ 96 mm. Two flat-panel Hamamatsu H8500 position-sensitive photomultiplier tubes (PSPMTs) are coupled to a pixellated NaI(Tl) scintillator which views the animal through a copper-beryllium (CuBe) parallel-hole collimator specially designed for {sup 125}I. Although the PSPMTs have insensitive areas at their edges and there is a physical gap, corrections for scintillation light collection at the junction between the two tubes results in a uniform response across the entire rectangular area of the detector. The system described has been developed to optimize both sensitivity and resolution for in-vivo imaging of small animals injected with iodinated compounds. We demonstrate an in-vivo application of this detector, particularly to SPECT, by imaging mice injected with approximately 10-15; spl mu/Ci of {sup 125}I.

  16. Changing image of correlation optics: introduction. (United States)

    Angelsky, Oleg V; Desyatnikov, Anton S; Gbur, Gregory J; Hanson, Steen G; Lee, Tim; Miyamoto, Yoko; Schneckenburger, Herbert; Wyant, James C


    This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers.

  17. Changing image of correlation optics: introduction

    DEFF Research Database (Denmark)

    Angelsky, Oleg V.; Desyatnikov, Anton S.; Gbur, Gregory J.;


    This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and illustrating current trends in vector singular optics, internal energy flows at light fields, optical science of materials, and new biomedical applications of lasers. (C)...

  18. Optical-thermal light-tissue interactions during photoacoustic imaging (United States)

    Gould, Taylor; Wang, Quanzeng; Pfefer, T. Joshua


    Photoacoustic imaging (PAI) has grown rapidly as a biomedical imaging technique in recent years, with key applications in cancer diagnosis and oximetry. In spite of these advances, the literature provides little insight into thermal tissue interactions involved in PAI. To elucidate these basic phenomena, we have developed, validated, and implemented a three-dimensional numerical model of tissue photothermal (PT) response to repetitive laser pulses. The model calculates energy deposition, fluence distributions, transient temperature and damage profiles in breast tissue with blood vessels and generalized perfusion. A parametric evaluation of these outputs vs. vessel diameter and depth, optical beam diameter, wavelength, and irradiance, was performed. For a constant radiant exposure level, increasing beam diameter led to a significant increase in subsurface heat generation rate. Increasing vessel diameter resulted in two competing effects - reduced mean energy deposition in the vessel due to light attenuation and greater thermal superpositioning due to reduced thermal relaxation. Maximum temperatures occurred either at the surface or in subsurface regions of the dermis, depending on vessel geometry and position. Results are discussed in terms of established exposure limits and levels used in prior studies. While additional experimental and numerical study is needed, numerical modeling represents a powerful tool for elucidating the effect of PA imaging devices on biological tissue.

  19. Improved antireflection coated microspheres for biological applications of optical tweezers (United States)

    Ferro, Valentina; Sonnberger, Aaron; Abdosamadi, Mohammad K.; McDonald, Craig; Schäffer, Erik; McGloin, David


    The success of optical tweezers in cellular biology1 is in part due to the wide range of forces that can be applied, from femto- to hundreds of pico-Newtons; nevertheless extending the range of applicable forces to the nanoNewton regime opens access to a new set of phenomena that currently lie beyond optical manipulation. A successful approach to overcome the conventional limits on trapping forces involves the optimization of the trapped probes. Jannasch et al.2 demonstrated that an anti-reflective shell of nanoporous titanium dioxide (aTiO2, nshell = 1.75) on a core particle made out of titanium dioxide in the anatase phase (cTiO2, ncore = 2.3) results in trappable microspheres capable to reach forces above 1 nN. Here we present how the technique can be further improved by coating the high refractive index microspheres with an additional anti-reflective shell made out of silica (SiO2). This external shell not only improves the trap stability for microspheres of different sizes, but also enables the use of functionalization techniques already established for commercial silica beads in biological experiments. We are also investigating the use of these new microspheres as probes to measure adhesion forces between intercellular adhesion molecule 1 (ICAM-1) and lymphocyte function-associated antigen 1 (LFA-1) in effector T-Cells and will present preliminary results comparing standard and high-index beads.

  20. Implementation Of A Prototype Digital Optical Cellular Image Processor (DOCIP) (United States)

    Huang, K. S.; Sawchuk, A. A.; Jenkins, B. K.; Chavel, P.; Wang, J. M.; Weber, A. G.; Wang, C. H.; Glaser, I.


    A processing element of a prototype digital optical cellular image processor (DOCIP) is implemented to demonstrate a particular parallel computing and interconnection architecture. This experimental digital optical computing system consists of a 2-D array of 54 optical logic gates, a 2-D array of 53 subholograms to provide interconnections between gates, and electronic input/output interfaces. The multi-facet interconnection hologram used in this system is fabricated by a computer-controlled optical system to offer very flexible interconnections.

  1. Advances in Optical Spectroscopy and Imaging of Breast Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Demos, S; Vogel, A J; Gandjbakhche, A H


    A review is presented of recent advances in optical imaging and spectroscopy and the use of light for addressing breast cancer issues. Spectroscopic techniques offer the means to characterize tissue components and obtain functional information in real time. Three-dimensional optical imaging of the breast using various illumination and signal collection schemes in combination with image reconstruction algorithms may provide a new tool for cancer detection and monitoring of treatment.

  2. Fiber optic direct Raman imaging system based on a hollow-core fiber bundle (United States)

    Inoue, S.; Katagiri, T.; Matsuura, Y.


    A Raman imaging system which combined a hollow fiber bundle and a direct imaging technique was constructed for high-speed endoscopic Raman imaging. The hollow fiber bundle is fabricated by depositing a silver thin film on the inner surface of pre-drawn glass capillary bundle. It performs as a fiber optic probe which transmits a Raman image with high signal-to-noise ratio because the propagating light is confined into the air core inducing little light scattering. The field of view on the sample is uniformly irradiated by the excitation laser light via the probe. The back-scattered image is collected by the probe and captured directly by an image sensor. A pair of thin film tunable filters is used to select target Raman band. This imaging system enables flexible and high-speed Raman imaging of biological tissues.

  3. Direct optical imaging of graphene in vitro by nonlinear femtosecond laser spectral reshaping. (United States)

    Li, Baolei; Cheng, Yingwen; Liu, Jie; Yi, Congwen; Brown, April S; Yuan, Hsiangkuo; Vo-Dinh, Tuan; Fischer, Martin C; Warren, Warren S


    Nonlinear optical microscopy, based on femtosecond laser spectral reshaping, characterized and imaged graphene samples made from different methods, both on slides and in a biological environment. This technique clearly discriminates between graphene flakes with different numbers of layers and reveals the distinct nonlinear optical properties of reduced graphene oxide as compared to mechanically exfoliated or chemical vapor deposition grown graphene. The nonlinearity makes it applicable to scattering samples (such as tissue) as opposed to previous methods, such as transmission. This was demonstrated by high-resolution imaging of breast cancer cells incubated with graphene flakes.


    Directory of Open Access Journals (Sweden)

    R. V. Anitropov


    Full Text Available Subject of Research. The research results, structural composition analysis and the parametric synthesis of the projected imaging and non-imaging optical systems were presented. We made an attempt to use the gained experience about imaging systems while designing non-imaging systems, by adapting the composition theory for the calculations of non-imaging systems. Several patterns were revealed, which provide a deeper understanding of the design process of non-imaging optical systems; measures of its optimization were proposed. Method. We investigated the applicability of the theory of composition and synthesis of non-imaging optical systems. The main provisions of the theory of composition are based on the division of all available optical elements in four types depending on their functionality, which corresponds to a modular design. Similar items were identified in non-imaging optical systems and adaptation of composition theory to their design became possible. Main Results. General design patterns of imaging and non-imaging optical systems were studied. Classification of systems, components, as well as technical and generic characteristics of imaging and non-imaging optical systems was determined. Search mechanism of the initial optical system by means of structural and parametric synthesis of non-imaging optical system was formalized. The basic elements were determined included in non-imaging systems and their classification by functionality was done. They were subdivided into basic, corrective, wide angle and high aperture ones. The rules for formation of these elements and their composition were determined: surface reflecting, refracting, spherical and nonspherical elements with total internal reflection. The foundations of composition theory for non-imaging optical systems were laid. The approbation of this method was carried out on the example of the illumination system calculation for surgical room. A 3D model of an illumination optical

  5. Biological Imaging Capability in the ABRS Facility on ISS (United States)

    Cox, David R.; Murdoch, T.; Regan, M. F.; Meshlberger, R. J.; Mortenson, T. E.; Albino, S. A.; Paul, A. L.; Ferl, R. J.


    This slide presentation reviews the Advanced Biological Research System (ABRS) on the International Space Station (ISS) and its biological imaging capability. The ABRS is an environmental control chamber. It has two indpendently controlled Experiment Research Chambers (ERCs) with temperature, relative humidity and carbon dioxide controls. ABRS is a third generation plant growth system. Several experiments are reviewed, with particular interest in the use of Green Fluorescent Protein (GFP) a non-destructive plant stress reporting mechanism, naturally found in jellyfish.

  6. Encoded diffractive optics for full-spectrum computational imaging (United States)

    Heide, Felix; Fu, Qiang; Peng, Yifan; Heidrich, Wolfgang


    Diffractive optical elements can be realized as ultra-thin plates that offer significantly reduced footprint and weight compared to refractive elements. However, such elements introduce severe chromatic aberrations and are not variable, unless used in combination with other elements in a larger, reconfigurable optical system. We introduce numerically optimized encoded phase masks in which different optical parameters such as focus or zoom can be accessed through changes in the mechanical alignment of a ultra-thin stack of two or more masks. Our encoded diffractive designs are combined with a new computational approach for self-calibrating imaging (blind deconvolution) that can restore high-quality images several orders of magnitude faster than the state of the art without pre-calibration of the optical system. This co-design of optics and computation enables tunable, full-spectrum imaging using thin diffractive optics.

  7. Encoded diffractive optics for full-spectrum computational imaging

    KAUST Repository

    Heide, Felix


    Diffractive optical elements can be realized as ultra-thin plates that offer significantly reduced footprint and weight compared to refractive elements. However, such elements introduce severe chromatic aberrations and are not variable, unless used in combination with other elements in a larger, reconfigurable optical system. We introduce numerically optimized encoded phase masks in which different optical parameters such as focus or zoom can be accessed through changes in the mechanical alignment of a ultra-thin stack of two or more masks. Our encoded diffractive designs are combined with a new computational approach for self-calibrating imaging (blind deconvolution) that can restore high-quality images several orders of magnitude faster than the state of the art without pre-calibration of the optical system. This co-design of optics and computation enables tunable, full-spectrum imaging using thin diffractive optics.

  8. Computational imaging using lightweight diffractive-refractive optics. (United States)

    Peng, Yifan; Fu, Qiang; Amata, Hadi; Su, Shuochen; Heide, Felix; Heidrich, Wolfgang


    Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.

  9. A simple multipurpose double-beam optical image analyzer

    CERN Document Server

    Popowicz, Adam


    In the paper we present a low cost optical device which splits the light in the focal plane into two separate optical paths and collimates it back into a single image plane, and where a selective information processing ca be carried out. The optical system is straightforward and easy implementable as it consists of only three lens and two mirrors. The system is dedicated for imaging in low-light-level conditions in which widely used optical devices, based on beam-splitters or dichroic mirrors, suffer from light loss. We expose examples of applications of our device, using a prototype model. The proposed optical system may be employed for: monitoring the objects located in different distances from observer (1), creating regions of different magnification within a single image plane (2), high dynamic range photometry (3), or imaging in two wavelength bands simultaneously (4).

  10. A simple multipurpose double-beam optical image analyzer (United States)

    Popowicz, A.; Blachowicz, T.


    In the paper we present a low cost optical device which splits the light in the focal plane into two separate optical paths and collimates it back into a single image plane, and where a selective information processing can be carried out. The optical system is straightforward and easily implementable as it consists of only three lenses and two mirrors. The system is dedicated for imaging in low-light-level conditions in which widely used optical devices, based on beam splitters or dichroic mirrors, suffer from light loss. We expose examples of applications of our device, using a prototype model. The proposed optical system may be employed for: monitoring the objects located at different distances from observer (1), creating regions of different magnification within a single image plane (2), high dynamic range photometry (3), or imaging in two wavelength bands simultaneously (4).

  11. Computational imaging using lightweight diffractive-refractive optics

    KAUST Repository

    Peng, Yifan


    Diffractive optical elements (DOE) show great promise for imaging optics that are thinner and more lightweight than conventional refractive lenses while preserving their light efficiency. Unfortunately, severe spectral dispersion currently limits the use of DOEs in consumer-level lens design. In this article, we jointly design lightweight diffractive-refractive optics and post-processing algorithms to enable imaging under white light illumination. Using the Fresnel lens as a general platform, we show three phase-plate designs, including a super-thin stacked plate design, a diffractive-refractive-hybrid lens, and a phase coded-aperture lens. Combined with cross-channel deconvolution algorithm, both spherical and chromatic aberrations are corrected. Experimental results indicate that using our computational imaging approach, diffractive-refractive optics is an alternative candidate to build light efficient and thin optics for white light imaging.

  12. Multiphoton imaging of biological samples during freezing and heating (United States)

    Breunig, H. G.; Uchugonova, A.; König, K.


    We applied multiphoton microscopic imaging to observe freezing and heating effects in plant- and animal cell samples. The experimental setups consisted of a multiphoton imaging system and a heating and cooling stage which allows for precise temperature control from liquid nitrogen temperature (-196°C 77 K) up to +600°C (873 K) with heating/freezing rates between 0.01 K/min and 150 K/min. Two multiphoton imaging systems were used: a system based on a modified optical microscope and a flexible mobile system. To illustrate the imaging capabilities, plant leafs as well as animal cells were microscopically imaged in vivo during freezing based on autofluorescence lifetime and intensity of intrinsic molecules. The measurements illustrate the usefulness of multiphoton imaging to investigate freezing effects on animal and plant cells.

  13. Confocal Imaging of Biological Tissues Using Second Harmonic Generation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, B-M.; Stoller, P.; Reiser, K.; Eichler, J.; Yan, M.; Rubenchik, A.; Da Silva, L.


    A confocal microscopy imaging system was devised to selectively detect Second harmonic signals generated by biological tissues. Several types of biological tissues were examined using this imaging system, including human teeth, bovine blood vessels, and chicken skin. All these tissues generated strong second harmonic signals. There is considerable evidence that the source of these signals in tissue is collagen. Collagen, the predominant component of most tissues, is known to have second order nonlinear susceptibility. This technique may have diagnostic usefulness in pathophysiological conditions characterized by changes in collagen structure including malignant transformation of nevi, progression of diabetic complications, and abnormalities in wound healing.

  14. New approach to optical imaging of tumors (United States)

    Achilefu, Samuel I.; Bugaj, Joseph E.; Dorshow, Richard B.; Jimenez, Hermo N.; Rajagopalan, Raghavan


    Site specific delivery of drugs and contrast agents to tumors protects normal tissues from the cytotoxic effect of drugs, and enhances the contrast between normal and diseased tissues. In optical medicine, biocompatible dyes can be used as phototherapeutics or as contrast agents. Previous studies have shown that the use of covalent or non-covalent dye conjugates of carriers such as antibiodies, liposomes, and polysaccharides improves the delivery of such molecules to tumors. However, large biomolecules can elicit adverse immunogenic reactions and also result in long blood clearance times, delaying visualization of target tissues. A viable alternative to this strategy is to use small bioactive molecule-dye conjugates. These molecules have several advantages over large biomolecules, including ease of synthesis of a variety of high purity compounds for combinatorial screening of new targets, enhanced diffusivity to solid tumors, and the ability to affect the pharmacokinetics of the conjugates by minor structural changes. Thus, we conjugated a near infrared absorbing dye to several bioactive peptides that specifically target overexpressed tumor receptors in established rat tumor lines. High tumor uptake of the conjugates was obtained without loss of either the peptide receptor affinity or the dye fluorescence. These findings demonstrate the efficacy of a small peptide-dye conjugate strategy for in vivo tumor imaging. Site-specific delivery of photodynamic therapy agents may also benefit from this approach.

  15. Fiber Optic Sensors For Detection of Toxic and Biological Threats

    Directory of Open Access Journals (Sweden)

    Jianming Yuan


    Full Text Available Protection of public and military personnel from chemical and biological warfareagents is an urgent and growing national security need. Along with this idea, we havedeveloped a novel class of fiber optic chemical sensors, for detection of toxic and biologicalmaterials. The design of these fiber optic sensors is based on a cladding modificationapproach. The original passive cladding of the fiber, in a small section, was removed and thefiber core was coated with a chemical sensitive material. Any change in the opticalproperties of the modified cladding material, due to the presence of a specific chemicalvapor, changes the transmission properties of the fiber and result in modal powerredistribution in multimode fibers. Both total intensity and modal power distribution (MPDmeasurements were used to detect the output power change through the sensing fibers. TheMPD technique measures the power changes in the far field pattern, i.e. spatial intensitymodulation in two dimensions. Conducting polymers, such as polyaniline and polypyrrole,have been reported to undergo a reversible change in conductivity upon exposure tochemical vapors. It is found that the conductivity change is accompanied by optical propertychange in the material. Therefore, polyaniline and polypyrrole were selected as the modifiedcladding material for the detection of hydrochloride (HCl, ammonia (NH3, hydrazine(H4N2, and dimethyl-methl-phosphonate (DMMP {a nerve agent, sarin stimulant},respectively. Several sensors were prepared and successfully tested. The results showeddramatic improvement in the sensor sensitivity, when the MPD method was applied. In thispaper, an overview on the developed class of fiber optic sensors is presented and supportedwith successful achieved results.

  16. Optical Properties and Biological Applications of Electromagnetically Coupled Metal Nanoparticles (United States)

    Sheikholeslami, Sassan Nathan

    The optical properties of metallic particles change dramatically as the size shrinks to the nanoscale. The familiar mirror-like sheen of bulk metals is replaced by the bright, sharp, colorful plasmonic resonances of nanoparticles. The resonances of plasmonic metal nanoparticles are highly tunable throughout the visible spectrum, depending on the size, shape, local dielectric environment, and proximity to other optical resonances. Fundamental and applied research in the nanoscience community in the past few decades has sought to understand and exploit these phenomena for biological applications. In this work, discrete nanoparticle assemblies were produced through biomolecular interactions and studied at the single particle level with darkfield spectroscopy. Pairs of gold nanoparticles tethered by DNA were utilized as molecular rulers to study the dynamics of DNA bending by the restriction enzyme EcoRV. These results substantiated that nanoparticle rulers, deemed "plasmon rulers", could measure the dynamics of single biomolecules with high throughput, long lifetime, and high temporal resolution. To extend these concepts for live cell studies, a plasmon ruler comprised of peptide-linked gold nanoparticle satellites around a core particle was synthesized and utilized to optically follow cell signaling pathways in vivo at the single molecule level. The signal provided by these plasmon rulers allowed continuous observation of caspase-3 activation at the single molecule level in living cells for over 2 hours, unambiguously identifying early stage activation of caspase-3 in apoptotic cells. In the last section of this dissertation, an experimental and theoretical study of electomagnetic coupling in asymmetric metal nanoparticle dimers is presented. A "heterodimer" composed of a silver particle and a gold particle is observed to have a novel coupling between a plasmon mode (free electron oscillations) and an inter-band absorption process (bound electron transitions). The

  17. Joint Applied Optics and Chinese Optics Letters feature introduction: digital holography and three-dimensional imaging


    Poon, Ting-Chung


    This feature issue serves as a pilot issue promoting the joint issue of Applied Optics and Chinese Optics Letters. It focuses upon topics of current relevance to the community working in the area of digital holography and 3-D imaging. (C) 2011 Optical Society of America

  18. Three dimensional reconstruction of conventional stereo optic disc image. (United States)

    Kong, H J; Kim, S K; Seo, J M; Park, K H; Chung, H; Park, K S; Kim, H C


    Stereo disc photograph was analyzed and reconstructed as 3 dimensional contour image to evaluate the status of the optic nerve head for the early detection of glaucoma and the evaluation of the efficacy of treatment. Stepwise preprocessing was introduced to detect the edge of the optic nerve head and retinal vessels and reduce noises. Paired images were registered by power cepstrum method and zero-mean normalized cross-correlation. After Gaussian blurring, median filter application and disparity pair searching, depth information in the 3 dimensionally reconstructed image was calculated by the simple triangulation formula. Calculated depth maps were smoothed through cubic B-spline interpolation and retinal vessels were visualized more clearly by adding reference image. Resulted 3 dimensional contour image showed optic cups, retinal vessels and the notching of the neural rim of the optic disc clearly and intuitively, helping physicians in understanding and interpreting the stereo disc photograph.

  19. Optical Imaging and Microscopy Techniques and Advanced Systems

    CERN Document Server

    Török, Peter


    This text on contemporary optical systems is intended for optical researchers and engineers, graduate students and optical microscopists in the biological and biomedical sciences. This second edition contains two completely new chapters. In addition most of the chapters from the first edition have been revised and updated. The book consists of three parts: The first discusses high-aperture optical systems, which form the backbone of optical microscopes. An example is a chapter new in the second edition on the emerging field of high numerical aperture diffractive lenses which seems to have particular promise in improving the correction of lenses. In this part particular attention is paid to optical data storage. The second part is on the use of non-linear optical techniques, including nonlinear optical excitation (total internal reflection fluorescence, second and third harmonic generation and two photon microscopy) and non-linear spectroscopy (CARS). The final part of the book presents miscellaneous technique...

  20. Optical-digital hybrid image search system in cloud environment (United States)

    Ikeda, Kanami; Kodate, Kashiko; Watanabe, Eriko


    To improve the versatility and usability of optical correlators, we developed an optical-digital hybrid image search system consisting of digital servers and an optical correlator that can be used to perform image searches in the cloud environment via a web browser. This hybrid system employs a simple method to obtain correlation signals and has a distributed network design. The correlation signals are acquired by using an encoder timing signal generated by a rotating disk, and the distributed network design facilitates the replacement and combination of the digital correlation server and the optical correlator.

  1. Living Brain Optical Imaging: Technology, Methods and Applications (United States)

    Tsytsarev, Vassiliy; Bernardelli, Chad; Maslov, Konstantin I.


    Within the last few decades, optical imaging methods have yielded revolutionary results when applied to all parts of the central nervous system. The purpose of this review is to analyze research possibilities and limitations of several novel imaging techniques and show some of the most interesting achievements obtained by these methods. Here we covered intrinsic optical imaging, voltage-sensitive dye, photoacoustic, optical coherence tomography, near-infrared spectroscopy and some other techniques. All of them are mainly applicable for experimental neuroscience but some of them also suitable for the clinical studies.

  2. The in vivo activation of persistent nanophosphors for optical imaging of vascularization, tumours and grafted cells (United States)

    Maldiney, Thomas; Bessière, Aurélie; Seguin, Johanne; Teston, Eliott; Sharma, Suchinder K.; Viana, Bruno; Bos, Adrie J. J.; Dorenbos, Pieter; Bessodes, Michel; Gourier, Didier; Scherman, Daniel; Richard, Cyrille


    Optical imaging for biological applications requires more sensitive tools. Near-infrared persistent luminescence nanoparticles enable highly sensitive in vivo optical detection and complete avoidance of tissue autofluorescence. However, the actual generation of persistent luminescence nanoparticles necessitates ex vivo activation before systemic administration, which prevents long-term imaging in living animals. Here, we introduce a new generation of optical nanoprobes, based on chromium-doped zinc gallate, whose persistent luminescence can be activated in vivo through living tissues using highly penetrating low-energy red photons. Surface functionalization of this photonic probe can be adjusted to favour multiple biomedical applications such as tumour targeting. Notably, we show that cells can endocytose these nanoparticles in vitro and that, after intravenous injection, we can track labelled cells in vivo and follow their biodistribution by a simple whole animal optical detection, opening new perspectives for cell therapy research and for a variety of diagnosis applications.

  3. Digital optical phase conjugation for delivering two-dimensional images through turbid media. (United States)

    Hillman, Timothy R; Yamauchi, Toyohiko; Choi, Wonshik; Dasari, Ramachandra R; Feld, Michael S; Park, YongKeun; Yaqoob, Zahid


    Optical transmission through complex media such as biological tissue is fundamentally limited by multiple light scattering. Precise control of the optical wavefield potentially holds the key to advancing a broad range of light-based techniques and applications for imaging or optical delivery. We present a simple and robust digital optical phase conjugation (DOPC) implementation for suppressing multiple light scattering. Utilizing wavefront shaping via a spatial light modulator (SLM), we demonstrate its turbidity-suppression capability by reconstructing the image of a complex two-dimensional wide-field target through a highly scattering medium. Employing an interferometer with a Sagnac-like ring design, we successfully overcome the challenging alignment and wavefront-matching constraints in DOPC, reflecting the requirement that the forward- and reverse-propagation paths through the turbid medium be identical. By measuring the output response to digital distortion of the SLM write pattern, we validate the sub-wavelength sensitivity of the system.

  4. Parallel optical sorting of biological cells using the generalized phase contrast method

    DEFF Research Database (Denmark)

    Rindorf, Lars; Bu, Minqiang; Glückstad, Jesper


    of biological cells in microfluidic systems exclusively using light. We demonstrate an optical cell sorter that uses simultaneous manipulation by multiple laser beams using the Generalized Phase Contrast method (GPC). The basic principle in an optical sorter is that the radiation force of the optical beam can...... push the biological cell from one microfluidic sheath flow to another. By incorporating a spatial light modulator the manipulation can be made parallel with multiple laser beams. We claim advantages over the serial optical sorters with only a single laser beam that has been demonstrated by others.......Optical forces are used to fixate biological cells with optical tweezers where numerous biological parameters and phenomena can be studied. Optical beams carry a small momentum which generates a weak optical force, but on a cellular level this force is strong enough to allow for manipulation...

  5. Optical color-image encryption and synthesis using coherent diffractive imaging in the Fresnel domain. (United States)

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R


    We propose a new method using coherent diffractive imaging for optical color-image encryption and synthesis in the Fresnel domain. An optical multiple-random-phase-mask encryption system is applied, and a strategy based on lateral translations of a phase-only mask is employed during image encryption. For the decryption, an iterative phase retrieval algorithm is applied to extract high-quality decrypted color images from diffraction intensity maps (i.e., ciphertexts). In addition, optical color-image synthesis is also investigated based on coherent diffractive imaging. Numerical results are presented to demonstrate feasibility and effectiveness of the proposed method. Compared with conventional interference methods, coherent diffractive imaging approach may open up a new research perspective or can provide an effective alternative for optical color-image encryption and synthesis.

  6. Classification of biological and non-biological fluvial particles using image processing and artificial neural network (United States)

    Shrestha, Bim Prasad; Shrestha, Nabin Kumar; Poudel, Laxman


    Particles flowing along with water largely affect safe drinking water, irrigation, aquatic life preservation and hydropower generation. This research describes activities that lead to development of fluvial particle characterization that includes detection of biological and non-biological particles and shape characterization using Image Processing and Artificial Neural Network (ANN). Fluvial particles are characterized based on multi spectral images processing using ANN. Images of wavelength of 630nm and 670nm are taken as most distinctive characterizing properties of biological and non-biological particles found in Bagmati River of Nepal. The samples were collected at pre-monsoon, monsoon and post-monsoon seasons. Random samples were selected and multi spectral images are processed using MATLAB 6.5. Thirty matrices were built from each sample. The obtained data of 42 rows and 60columns were taken as input training with an output matrix of 42 rows and 2 columns. Neural Network of Perceptron model was created using a transfer function. The system was first validated and later on tested at 18 different strategic locations of Bagmati River of Kathmandu Valley, Nepal. This network classified biological and non biological particles. Development of new non-destructive technique to characterize biological and non-biological particles from fluvial sample in a real time has a significance breakthrough. This applied research method and outcome is an attractive model for real time monitoring of particles and has many applications that can throw a significant outlet to many researches and for effective utilization of water resources. It opened a new horizon of opportunities for basic and applied research at Kathmandu University in Nepal.

  7. Compound focusing mirror and X-ray waveguide optics for coherent imaging and nano-diffraction. (United States)

    Salditt, Tim; Osterhoff, Markus; Krenkel, Martin; Wilke, Robin N; Priebe, Marius; Bartels, Matthias; Kalbfleisch, Sebastian; Sprung, Michael


    A compound optical system for coherent focusing and imaging at the nanoscale is reported, realised by high-gain fixed-curvature elliptical mirrors in combination with X-ray waveguide optics or different cleaning apertures. The key optical concepts are illustrated, as implemented at the Göttingen Instrument for Nano-Imaging with X-rays (GINIX), installed at the P10 coherence beamline of the PETRA III storage ring at DESY, Hamburg, and examples for typical applications in biological imaging are given. Characteristic beam configurations with the recently achieved values are also described, meeting the different requirements of the applications, such as spot size, coherence or bandwidth. The emphasis of this work is on the different beam shaping, filtering and characterization methods.

  8. Optical molecular imaging for detection of Barrett's-associated neoplasia

    Institute of Scientific and Technical Information of China (English)

    Nadhi Thekkek; Sharmila Anandasabapathy; Rebecca Richards-Kortum


    Recent advancements in the endoscopic imaging of Barrett's esophagus can be used to probe a wide range of optical properties that are altered with neoplastic progression.This review summarizes relevant changes in optical properties as well as imaging approaches that measures those changes.Wide-field imaging approaches include narrow-band imaging that measures changes in light scattering and absorption,and autofluorescence imaging that measure changes in endogenous fluorophores.High-resolution imaging approaches include optical coherence tomography,endocytoscopy,confocal microendoscopy,and high-resolution microendoscopy.These technologies,some coupled with an appropriate contrast agent,can measure differences in glandular morphology,nuclear morphology,or vascular alterations associated with neoplasia.Advances in targeted contrast agents are further discussed.Studies that have explored these technologies are highlighted;as are the advantages and limitations of each.

  9. Three-dimensional microscopy and sectional image reconstruction using optical scanning holography. (United States)

    Lam, Edmund Y; Zhang, Xin; Vo, Huy; Poon, Ting-Chung; Indebetouw, Guy


    Fast acquisition and high axial resolution are two primary requirements for three-dimensional microscopy. However, they are sometimes conflicting: imaging modalities such as confocal imaging can deliver superior resolution at the expense of sequential acquisition at different axial planes, which is a time-consuming process. Optical scanning holography (OSH) promises to deliver a good trade-off between these two goals. With just a single scan, we can capture the entire three-dimensional volume in a digital hologram; the data can then be processed to obtain the individual sections. An accurate modeling of the imaging system is key to devising an appropriate image reconstruction algorithm, especially for real data where random noise and other imaging imperfections must be taken into account. In this paper we demonstrate sectional image reconstruction by applying an inverse imaging sectioning technique to experimental OSH data of biological specimens and visualizing the sections using the OSA Interactive Science Publishing software.

  10. Visualization of biological texture using correlation coefficient images. (United States)

    Sviridov, Alexander P; Ulissi, Zachary; Chernomordik, Victor; Hassan, Moinuddin; Gandjbakhche, Amir H


    Subsurface structural features of biological tissue are visualized using polarized light images. The technique of Pearson correlation coefficient analysis is used to reduce blurring of these features by unpolarized backscattered light and to visualize the regions of high statistical similarities within the noisy tissue images. It is shown that under certain conditions, such correlation coefficient maps are determined by the textural character of tissues and not by the chosen region of interest, providing information on tissue structure. As an example, the subsurface texture of a demineralized tooth sample is enhanced from a noisy polarized light image.

  11. Method and apparatus to image biological interactions in plants (United States)

    Weisenberger, Andrew; Bonito, Gregory M.; Reid, Chantal D.; Smith, Mark Frederick


    A method to dynamically image the actual translocation of molecular compounds of interest in a plant root, root system, and rhizosphere without disturbing the root or the soil. The technique makes use of radioactive isotopes as tracers to label molecules of interest and to image their distribution in the plant and/or soil. The method allows for the study and imaging of various biological and biochemical interactions in the rhizosphere of a plant, including, but not limited to, mycorrhizal associations in such regions.

  12. Magnetic resonance imaging of luxury perfusion of the optic nerve head in anterior ischemic optic neuropathy. (United States)

    Yovel, Oren S; Katz, Miriam; Leiba, Hana


    A 49-year-old woman with painless reduction in visual acuity in her left eye was found to have nonarteritic anterior ischemic optic neuropathy (NAION). Fluorescein angiography revealed optic disc capillary leakage consistent with "luxury perfusion." Contrast-enhanced FLAIR magnetic resonance imaging (MRI) showed marked enhancement of the left optic disc. Resolution of the optic disc edema and the MRI abnormalities followed a similar time course. This report appears unique in documenting the MRI findings of luxury perfusion in NAION.

  13. An adaptive optics imaging system designed for clinical use. (United States)

    Zhang, Jie; Yang, Qiang; Saito, Kenichi; Nozato, Koji; Williams, David R; Rossi, Ethan A


    Here we demonstrate a new imaging system that addresses several major problems limiting the clinical utility of conventional adaptive optics scanning light ophthalmoscopy (AOSLO), including its small field of view (FOV), reliance on patient fixation for targeting imaging, and substantial post-processing time. We previously showed an efficient image based eye tracking method for real-time optical stabilization and image registration in AOSLO. However, in patients with poor fixation, eye motion causes the FOV to drift substantially, causing this approach to fail. We solve that problem here by tracking eye motion at multiple spatial scales simultaneously by optically and electronically integrating a wide FOV SLO (WFSLO) with an AOSLO. This multi-scale approach, implemented with fast tip/tilt mirrors, has a large stabilization range of ± 5.6°. Our method consists of three stages implemented in parallel: 1) coarse optical stabilization driven by a WFSLO image, 2) fine optical stabilization driven by an AOSLO image, and 3) sub-pixel digital registration of the AOSLO image. We evaluated system performance in normal eyes and diseased eyes with poor fixation. Residual image motion with incremental compensation after each stage was: 1) ~2-3 arc minutes, (arcmin) 2) ~0.5-0.8 arcmin and, 3) ~0.05-0.07 arcmin, for normal eyes. Performance in eyes with poor fixation was: 1) ~3-5 arcmin, 2) ~0.7-1.1 arcmin and 3) ~0.07-0.14 arcmin. We demonstrate that this system is capable of reducing image motion by a factor of ~400, on average. This new optical design provides additional benefits for clinical imaging, including a steering subsystem for AOSLO that can be guided by the WFSLO to target specific regions of interest such as retinal pathology and real-time averaging of registered images to eliminate image post-processing.

  14. Progress of Focusing X-ray and Gamma-ray Optics for Small Animal Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pivovaroff, M J; Funk, T; Barber, W C; Ramsey, B D; Hasegawa, B H


    Significant effort is currently being devoted to the development of noninvasive imaging systems that allow in vivo assessment of biological and biomolecular interactions in mice and other small animals. Ideally, one would like to discern these functional and metabolic relationships with in vivo radionuclide imaging at spatial resolutions approaching those that can be obtained using the anatomical imaging techniques (i.e., <100 {micro}m), which would help to answer outstanding questions in many areas of biomedicine. In this paper, we report progress on our effort to develop high-resolution focusing X-ray and gamma-ray optics for small-animal radionuclide imaging. The use of reflective optics, in contrast to methods that rely on absorptive collimation like single- or multiple-pinhole cameras, decouples spatial resolution from sensitivity (efficiency). Our feasibility studies have refined and applied ray-tracing routines to design focusing optics for small animal studies. We also have adopted a replication technique to manufacture the X-ray mirrors, and which in experimental studies have demonstrated a spatial resolution of {approx}190 {micro}m. We conclude that focusing optics can be designed and fabricated for gamma-ray energies, and with spatial resolutions, and field of view suitable for in vivo biological studies. While the efficiency of a single optic is limited, fabrication methods now are being developed that may make it possible to develop imaging systems with multiple optics that could collect image data over study times that would be practical for performing radionuclide studies of small animals.

  15. Mitigation Approaches for Optical Imaging through Clouds and Fog (United States)


    communications, remote sensing, and imaging. The advantages of performing imaging in the optical band are manifold. Modern Lidar and Ladar systems are preferred...image, the area search rate is low for this approach. This method is widely used in LIDAR applications in clear weather conditions. One intermediate...the average. This can be done by forcing the expectation of the Froebenius norm of H to 1. The resulting receiving image at the photodetectors can be

  16. Analysis of cross-sectional image filters for evaluating nonaveraged optical microangiography images. (United States)

    Reif, Roberto; Yousefi, Siavash; Choi, Woo June; Wang, Ruikang K


    Optical microangiography (OMAG) is a method that enables the noninvasive extraction of blood vessels within biological tissues. OMAG B-frames are prone to noise; therefore, techniques such as B-frame averaging have been applied to reduce these effects. A drawback of this method is that the total acquisition time and amount of data collected are increased; hence, the data are susceptible to motion artifacts and decorrelation. In this paper we propose using an image filter on a nonaveraged OMAG B-frame to reduce its noise. Consequently, B-frames comparable to the averaged OMAG B-frame are obtained, while reducing the total acquisition and processing time. The method is tested with two different systems, a high-resolution spectral domain and a relatively low-resolution swept-source optical coherence tomography system. It is demonstrated that the weighted average filter produces the lowest B-frame error; however, all filters produce comparable results when quantifying the en face projection view image.

  17. Progresses in 3D integral imaging with optical processing

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Corral, Manuel; Martinez-Cuenca, Raul; Saavedra, Genaro; Navarro, Hector; Pons, Amparo [Department of Optics. University of Valencia. Calle Doctor Moliner 50, E46 100, Burjassot (Spain); Javidi, Bahram [Electrical and Computer Engineering Department, University of Connecticut, Storrs, CT 06269-1157 (United States)], E-mail:


    Integral imaging is a promising technique for the acquisition and auto-stereoscopic display of 3D scenes with full parallax and without the need of any additional devices like special glasses. First suggested by Lippmann in the beginning of the 20th century, integral imaging is based in the intersection of ray cones emitted by a collection of 2D elemental images which store the 3D information of the scene. This paper is devoted to the study, from the ray optics point of view, of the optical effects and interaction with the observer of integral imaging systems.

  18. Sub-diffraction-Limit Imaging in Optical Hyperlens

    Institute of Scientific and Technical Information of China (English)

    HU Ji-Gang; WANG Pei; LU Yong-Hua; MING Hai; CHEN Chun-Chong; CHEN Jun-Xue


    @@ Sub-diffraction-limit imaging in the optical hyperlens based on cylindrical metamaterials is studied. Some param-eters of hyperlens, such as the dispersive relation and the divergence angle of imaging, are numerically analysed with the ray trajectory method and effective medium theory. The dependence of imaging properties on dielectric constant is discussed. As a result, a 0° divergence angle is obtained for the best imaging effect. This work will be helpful for the design, structure fabrication and resolution improvement of the optical hyperlens.

  19. Fluorescent Dendrimer Nanoconjugates as Advanced Probes for Biological Imaging (United States)

    Reilly, Daniel; Kim, Sung Hoon; Katzenellenbogen, John A.; Schroeder, Charles M.


    Recent advances in fluorescence microscopy have enabled improvements in spatial resolution for biological imaging. However, there is a strong need for development of advanced fluorescent probes to enable a molecular-scale understanding of biological events. In this work, we report the development of a new class of probes for fluorescence imaging based on dye-conjugated dendrimer nanoconjugates. We utilize molecular-scale dendritic scaffolds as fluorescent probes, thereby enabling conjugation of multiple dyes and linkers to the scaffold periphery. In particular, we use polyamidoamine dendrimers as molecular scaffolds, wherein dye conjugation can be varied over a wide range. Single molecule fluorescence imaging shows that dendrimer nanoconjugates are far brighter than single fluorophores, resulting in increased localization precision. In addition, we further developed a new set of remarkably photostable probes by conjugating photoprotective triplet state quenchers directly onto the dendritic scaffold. We observe large increases in the photobleaching times compared to single dyes and reduced transient dark states (blinking). Overall, we believe that these new probes will allow for single molecule imaging over long time scales, enabling new vistas in biological imaging.

  20. Adaptive optics technology for high-resolution retinal imaging. (United States)

    Lombardo, Marco; Serrao, Sebastiano; Devaney, Nicholas; Parravano, Mariacristina; Lombardo, Giuseppe


    Adaptive optics (AO) is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have reviewed AO technology for retinal imaging, providing information on the core components of an AO retinal camera. The most commonly used wavefront sensing and correcting elements are discussed. Furthermore, we discuss current applications of AO imaging to a population of healthy adults and to the most frequent causes of blindness, including diabetic retinopathy, age-related macular degeneration and glaucoma. We conclude our work with a discussion on future clinical prospects for AO retinal imaging.

  1. Adaptive Optics Technology for High-Resolution Retinal Imaging

    Directory of Open Access Journals (Sweden)

    Giuseppe Lombardo


    Full Text Available Adaptive optics (AO is a technology used to improve the performance of optical systems by reducing the effects of optical aberrations. The direct visualization of the photoreceptor cells, capillaries and nerve fiber bundles represents the major benefit of adding AO to retinal imaging. Adaptive optics is opening a new frontier for clinical research in ophthalmology, providing new information on the early pathological changes of the retinal microstructures in various retinal diseases. We have reviewed AO technology for retinal imaging, providing information on the core components of an AO retinal camera. The most commonly used wavefront sensing and correcting elements are discussed. Furthermore, we discuss current applications of AO imaging to a population of healthy adults and to the most frequent causes of blindness, including diabetic retinopathy, age-related macular degeneration and glaucoma. We conclude our work with a discussion on future clinical prospects for AO retinal imaging.

  2. Electro-Optic Imaging Fourier Transform Spectral Polarimeter Project (United States)

    National Aeronautics and Space Administration — Boulder Nonlinear Systems, Inc. (BNS) proposes to develop an Electro-Optic Imaging Fourier Transform Spectral Polarimeter (E-O IFTSP). The polarimetric system is...

  3. Single Molecule Imaging in Living Cell with Optical Method

    Institute of Scientific and Technical Information of China (English)


    Significance, difficult, international developing actuality and our completed works for single molecules imaging in living cell with optical method are described respectively. Additionally we give out some suggestions for the technology development further.

  4. Coded access optical sensor (CAOS) imager and applications (United States)

    Riza, Nabeel A.


    Starting in 2001, we proposed and extensively demonstrated (using a DMD: Digital Micromirror Device) an agile pixel Spatial Light Modulator (SLM)-based optical imager based on single pixel photo-detection (also called a single pixel camera) that is suited for operations with both coherent and incoherent light across broad spectral bands. This imager design operates with the agile pixels programmed in a limited SNR operations starring time-multiplexed mode where acquisition of image irradiance (i.e., intensity) data is done one agile pixel at a time across the SLM plane where the incident image radiation is present. Motivated by modern day advances in RF wireless, optical wired communications and electronic signal processing technologies and using our prior-art SLM-based optical imager design, described using a surprisingly simple approach is a new imager design called Coded Access Optical Sensor (CAOS) that has the ability to alleviate some of the key prior imager fundamental limitations. The agile pixel in the CAOS imager can operate in different time-frequency coding modes like Frequency Division Multiple Access (FDMA), Code-Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA). Data from a first CAOS camera demonstration is described along with novel designs of CAOS-based optical instruments for various applications.

  5. Plenoptic microscope based on laser optical feedback imaging (LOFI)

    CERN Document Server

    Glastre, W; Jacquin, O; de Chatellus, H Guillet; Lacot, E


    We present an overview of the performances of a plenoptic microscope which combines the high sensitivity of a laser optical feedback imaging setup , the high resolution of optical synthetic aperture and a shot noise limited signal to noise ratio by using acoustic photon tagging. By using an adapted phase filtering, this microscope allows phase drift correction and numerical aberration compensation (defocusing, coma, astigmatism ...). This new kind of microscope seems to be well adapted to make deep imaging through scattering and heterogeneous media.

  6. Imaging of acoustic fields using optical feedback interferometry. (United States)

    Bertling, Karl; Perchoux, Julien; Taimre, Thomas; Malkin, Robert; Robert, Daniel; Rakić, Aleksandar D; Bosch, Thierry


    This study introduces optical feedback interferometry as a simple and effective technique for the two-dimensional visualisation of acoustic fields. We present imaging results for several pressure distributions including those for progressive waves, standing waves, as well as the diffraction and interference patterns of the acoustic waves. The proposed solution has the distinct advantage of extreme optical simplicity and robustness thus opening the way to a low cost acoustic field imaging system based on mass produced laser diodes.

  7. Peptide-Based Optical uPAR Imaging for Surgery

    DEFF Research Database (Denmark)

    Juhl, Karina; Christensen, Anders; Persson, Morten;


    Near infrared intra-operative optical imaging is an emerging technique with clear implications for improved cancer surgery by enabling a more distinct delineation of the tumor margins during resection. This modality has the potential to increase the number of patients having a curative radical......-operative optical guidance in cancer surgery to ensure complete removal of tumors while preserving adjacent, healthy tissue....

  8. Direct optical imaging of structural inhomogeneities in crystalline materials. (United States)

    Grigorev, A M


    A method for optical imaging of structural inhomogeneities in crystalline materials is proposed, based on the differences in the optical properties of the structural inhomogeneity and the homogeneous material near the fundamental absorption edge of the crystalline material. The method can be used to detect defects in both semiconductors and insulators.

  9. Computer Aided Interpretation Approach for Optical Tomographic Images

    CERN Document Server

    Klose, Christian D; Netz, Uwe; Beuthan, Juergen; Hielscher, Andreas H


    A computer-aided interpretation approach is proposed to detect rheumatic arthritis (RA) of human finger joints in optical tomographic images. The image interpretation method employs a multi-variate signal detection analysis aided by a machine learning classification algorithm, called Self-Organizing Mapping (SOM). Unlike in previous studies, this allows for combining multiple physical image parameters, such as minimum and maximum values of the absorption coefficient for identifying affected and not affected joints. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index, and mutual information. Different methods (i.e., clinical diagnostics, ultrasound imaging, magnet resonance imaging and inspection of optical tomographic images), were used as "ground truth"-benchmarks to determine the performance of image interpretations. Using data from 100 finger joints, findings suggest that some parameter combinations lead to higher sensitivities while...

  10. Ultrafast optical imaging technology: principles and applications of emerging methods (United States)

    Mikami, Hideharu; Gao, Liang; Goda, Keisuke


    High-speed optical imaging is an indispensable technology for blur-free observation of fast transient dynamics in virtually all areas including science, industry, defense, energy, and medicine. High temporal resolution is particularly important for microscopy as even a slow event appears to occur "fast" in a small field of view. Unfortunately, the shutter speed and frame rate of conventional cameras based on electronic image sensors are significantly constrained by their electrical operation and limited storage. Over the recent years, several unique and unconventional approaches to high-speed optical imaging have been reported to circumvent these technical challenges and achieve a frame rate and shutter speed far beyond what can be reached with the conventional image sensors. In this article, we review the concepts and principles of such ultrafast optical imaging methods, compare their advantages and disadvantages, and discuss an entirely new class of applications that are possible using them.

  11. Sagittal laser optical tomography for imaging of rheumatoid finger joints

    Energy Technology Data Exchange (ETDEWEB)

    Hielscher, Andreas H [Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027 (United States); Klose, Alexander D [Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027 (United States); Scheel, Alexander K [Department of Nephrology and Rheumatology, Georg-August University, Goettingen (Germany); Moa-Anderson, Bryte [Departments of Biomedical Engineering and Radiology, Columbia University, New York, NY 10027 (United States); Backhaus, Marina [Department of Rheumatology and Clinical Immunology, Charite University Hospital, Berlin (Germany); Netz, Uwe [Institute for Medical Physics and Laser Medicine, Free University of Berlin, Berlin (Germany); Beuthan, Juergen [Institute for Medical Physics and Laser Medicine, Free University of Berlin, Berlin (Germany)


    We present a novel optical tomographic imaging system that was designed to determine two-dimensional spatial distribution of optical properties in a sagittal plane through finger joints. The system incorporates a single laser diode and a single silicon photodetector into a scanning device that records spatially resolved light intensities as they are transmitted through a finger. These data are input to a model-based iterative image reconstruction (MOBIIR) scheme, which uses the equation of radiative transfer (ERT) as a forward model for light propagation through tissue. We have used this system to obtain tomographic images of six proximal interphalangeal finger joints from two patients with rheumatoid arthritis. The optical images were compared to clinical symptoms and ultrasound images.

  12. Optical Synchrotron Radiation Beam Imaging with a Digital Mask

    Energy Technology Data Exchange (ETDEWEB)

    Fiorito, R. B. [University of Maryland, College Park, MD (United States); Zhang, H. D. [University of Maryland, College Park, MD (United States); Corbett, W. J. [SLAC, Menlo Park, CA (United States); Fisher, A. S. [SLAC, Menlo Park, CA (United States); Mok, W. Y. [SLAC, Menlo Park, CA (United States); Tian, K. [SLAC, Menlo Park, CA (United States); Douglas, D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Wilson, F. G. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhang, S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Mitsuhashi, T. M. [KEK, Tsukuba (Japan); Shkvarunets, A. G. [University of Maryland, College Park, MD (United States)


    We have applied a new imaging/optical masking technique, which employs a digital micro-mirror device (DMD) and optical synchrotron radiation (OSR), to perform high dynamic range (DR) beam imaging at the JLAB Energy Recovery Linac and the SLAC/SPEAR3 Synchrotron Light Source. The OSR from the beam is first focused onto the DMD to produce a primary image; selected areas of this image are spatially filtered by controlling the state of individual micro-mirrors; and finally, the filtered image is refocused onto a CCD camera. At JLAB this technique has been used successfully to view the beam halo with a DR ~ 105. At SPEAR3 the DMD was used to filter out the bright core of the stored beam to study the turn-by-turn dynamics of the 10-3 weaker injected beam. We describe the optical performance, present limitations and our plans to improve the DR of both experimental systems.

  13. New variational image decomposition model for simultaneously denoising and segmenting optical coherence tomography images. (United States)

    Duan, Jinming; Tench, Christopher; Gottlob, Irene; Proudlock, Frank; Bai, Li


    Optical coherence tomography (OCT) imaging plays an important role in clinical diagnosis and monitoring of diseases of the human retina. Automated analysis of optical coherence tomography images is a challenging task as the images are inherently noisy. In this paper, a novel variational image decomposition model is proposed to decompose an OCT image into three components: the first component is the original image but with the noise completely removed; the second contains the set of edges representing the retinal layer boundaries present in the image; and the third is an image of noise, or in image decomposition terms, the texture, or oscillatory patterns of the original image. In addition, a fast Fourier transform based split Bregman algorithm is developed to improve computational efficiency of solving the proposed model. Extensive experiments are conducted on both synthesised and real OCT images to demonstrate that the proposed model outperforms the state-of-the-art speckle noise reduction methods and leads to accurate retinal layer segmentation.

  14. Graphene-Based Optical Biosensors and Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zhiwen; He, Shijiang; Pei, Hao; Du, Dan; Fan, Chunhai; Lin, Yuehe


    This chapter focuses on the design, fabrication and application of graphene based optical nanobiosensors. The emerging graphene based optical nanobiosensors demonstrated the promising bioassay and biomedical applications thanking to the unique optical features of graphene. According to the different applications, the graphene can be tailored to form either fluorescent emitter or efficient fluorescence quencher. The exceptional electronic feature of graphene makes it a powerful platform for fabricating the SPR and SERS biosensors. Today the graphene based optical biosensors have been constructed to detect various targets including ions, small biomolecules, DNA/RNA and proteins. This chapter reviews the recent progress in graphene-based optical biosensors and discusses the opportunities and challenges in this field.

  15. Volume scanning electron microscopy for imaging biological ultrastructure. (United States)

    Titze, Benjamin; Genoud, Christel


    Electron microscopy (EM) has been a key imaging method to investigate biological ultrastructure for over six decades. In recent years, novel volume EM techniques have significantly advanced nanometre-scale imaging of cells and tissues in three dimensions. Previously, this had depended on the slow and error-prone manual tasks of cutting and handling large numbers of sections, and imaging them one-by-one with transmission EM. Now, automated volume imaging methods mostly based on scanning EM (SEM) allow faster and more reliable acquisition of serial images through tissue volumes and achieve higher z-resolution. Various software tools have been developed to manipulate the acquired image stacks and facilitate quantitative analysis. Here, we introduce three volume SEM methods: serial block-face electron microscopy (SBEM), focused ion beam SEM (FIB-SEM) and automated tape-collecting ultramicrotome SEM (ATUM-SEM). We discuss and compare their capabilities, provide an overview of the full volume SEM workflow for obtaining 3D datasets and showcase different applications for biological research.

  16. Accuracy requirements of optical linear algebra processors in adaptive optics imaging systems. (United States)

    Downie, J D; Goodman, J W


    A ground-based adaptive optics imaging telescope system attempts to improve image quality by measuring and correcting for atmospherically induced wavefront aberrations. The necessary control computations during each cycle will take a finite amount of time, which adds to the residual error variance since the atmosphere continues to change during that time. Thus an optical processor may be well-suited for this task. This paper investigates this possibility by studying the accuracy requirements in a general optical processor that will make it competitive with, or superior to, a conventional digital computer for adaptive optics use.

  17. Sensor-Based Technique for Manually Scanned Hand-Held Optical Coherence Tomography Imaging

    Directory of Open Access Journals (Sweden)

    Paritosh Pande


    Full Text Available Hand-held optical coherence tomography (OCT imaging probes offer flexibility to image sites that are otherwise challenging to access. While the majority of hand-held imaging probes utilize galvanometer- or MEMS-scanning mirrors to transversely scan the imaging beam, these probes are commonly limited to lateral fields-of-view (FOV of only a few millimeters. The use of a freehand manually scanned probe can significantly increase the lateral FOV. However, using the traditional fixed-rate triggering scheme for data acquisition in a manually scanned probe results in imaging artifacts due to variations in the scan velocity of the imaging probe. These artifacts result in a structurally inaccurate image of the sample. In this paper, we present a sensor-based manual scanning technique for OCT imaging, where real-time feedback from an optical motion sensor is used to trigger data acquisition. This technique is able to circumvent the problem of motion artifacts during manual scanning by adaptively altering the trigger rate based on the instantaneous scan velocity, enabling OCT imaging over a large lateral FOV. The feasibility of the proposed technique is demonstrated by imaging several biological and nonbiological samples.

  18. Optical drug monitoring: photoacoustic imaging of nanosensors to monitor therapeutic lithium in vivo. (United States)

    Cash, Kevin J; Li, Chiye; Xia, Jun; Wang, Lihong V; Clark, Heather A


    Personalized medicine could revolutionize how primary care physicians treat chronic disease and how researchers study fundamental biological questions. To realize this goal, we need to develop more robust, modular tools and imaging approaches for in vivo monitoring of analytes. In this report, we demonstrate that synthetic nanosensors can measure physiologic parameters with photoacoustic contrast, and we apply that platform to continuously track lithium levels in vivo. Photoacoustic imaging achieves imaging depths that are unattainable with fluorescence or multiphoton microscopy. We validated the photoacoustic results that illustrate the superior imaging depth and quality of photoacoustic imaging with optical measurements. This powerful combination of techniques will unlock the ability to measure analyte changes in deep tissue and will open up photoacoustic imaging as a diagnostic tool for continuous physiological tracking of a wide range of analytes.

  19. Review on Matching Infrared Face Images to Optical Face Images using LBP

    Directory of Open Access Journals (Sweden)

    Kamakhaya Argulewar


    Full Text Available In biometric research and many security areas, it is very difficult task to match the images which is captured by different devices. Large gap exist between them because they relates with different classes. Matching optical face images to infrared face images is one of the difficult task in face biometric. Large difference exists between infrared and optical face images because they belong to multiple classes. Converting the samples of multimodality into common feature space is the main objective of this project. Different class of images is relating by coordinating separate feature for classes .It is mainly used in heterogeneous face recognition. The new method has been developing for identification of heterogeneous face identification. Training set contains the images from different modalities. Initially the infrared image is preprocessed by applying Gaussian filter, difference of Gaussian and CSDN filters are apply on infrared face image. After preprocessing next step to extracting the feature by using LBP(local binary pattern feature extraction then relevance machine classifier is used to identify the best matching optical image from the corresponding infrared images from the optical images dataset. By processing this technique our system efficiently match the infrared and optical face images.

  20. A General Epipolar-Line Model between Optical and SAR Images and Used in Image Matching

    Directory of Open Access Journals (Sweden)

    Shuai Xing


    Full Text Available The search space and strategy are important for optical and SAR image matching. In this paper a general epipolar-line model has been proposed between linear array push-broom optical and SAR images. Then a dynamic approximate epipolar-line constraint model (DAELCM has been constructed and used to construct a new image matching algorithm with Harris operator and CRA. Experimental results have shown that the general epipolar-line model is valid and successfully used in optical and SAR image matching, and effectively limits the search space and decreased computation.

  1. Magneto-optical system for high speed real time imaging (United States)

    Baziljevich, M.; Barness, D.; Sinvani, M.; Perel, E.; Shaulov, A.; Yeshurun, Y.


    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated.

  2. Implied Movement in Static Images Reveals Biological Timing Processing

    Directory of Open Access Journals (Sweden)

    Francisco Carlos Nather


    Full Text Available Visual perception is adapted toward a better understanding of our own movements than those of non-conspecifics. The present study determined whether time perception is affected by pictures of different species by considering the evolutionary scale. Static (“S” and implied movement (“M” images of a dog, cheetah, chimpanzee, and man were presented to undergraduate students. S and M images of the same species were presented in random order or one after the other (S-M or M-S for two groups of participants. Movement, Velocity, and Arousal semantic scales were used to characterize some properties of the images. Implied movement affected time perception, in which M images were overestimated. The results are discussed in terms of visual motion perception related to biological timing processing that could be established early in terms of the adaptation of humankind to the environment.

  3. Probing biological nanotopology via diffusion of weakly constrained plasmonic nanorods with optical coherence tomography. (United States)

    Chhetri, Raghav K; Blackmon, Richard L; Wu, Wei-Chen; Hill, David B; Button, Brian; Casbas-Hernandez, Patricia; Troester, Melissa A; Tracy, Joseph B; Oldenburg, Amy L


    Biological materials exhibit complex nanotopology, i.e., a composite liquid and solid phase structure that is heterogeneous on the nanoscale. The diffusion of nanoparticles in nanotopological environments can elucidate biophysical changes associated with pathogenesis and disease progression. However, there is a lack of methods that characterize nanoprobe diffusion and translate easily to in vivo studies. Here, we demonstrate a method based on optical coherence tomography (OCT) to depth-resolve diffusion of plasmon-resonant gold nanorods (GNRs) that are weakly constrained by the biological tissue. By using GNRs that are on the size scale of the polymeric mesh, their Brownian motion is minimally hindered by intermittent collisions with local macromolecules. OCT depth-resolves the particle-averaged translational diffusion coefficient (DT) of GNRs within each coherence volume, which is separable from the nonequilibrium motile activities of cells based on the unique polarized light-scattering properties of GNRs. We show how this enables minimally invasive imaging and monitoring of nanotopological changes in a variety of biological models, including extracellular matrix (ECM) remodeling as relevant to carcinogenesis, and dehydration of pulmonary mucus as relevant to cystic fibrosis. In 3D ECM models, DT of GNRs decreases with both increasing collagen concentration and cell density. Similarly, DT of GNRs is sensitive to human bronchial-epithelial mucus concentration over a physiologically relevant range. This novel method comprises a broad-based platform for studying heterogeneous nanotopology, as distinct from bulk viscoelasticity, in biological milieu.

  4. Compensating focusing for space hyper spectral imager's fore optical system

    Institute of Scientific and Technical Information of China (English)

    Yicha Zhang; Wei Liu


    @@ The performance of space hyper spectral imager is severely affected by turbulent orbit temperature. Turbulence results in a defocus in the fore optical system of the imager. To address this problem, a focusing system is added. A number of simulation methods are applied on the fore optical system to study the relationship between temperature and focusing. In addition, this process is conducted to obtain a practical reference for focusing while the imager is flying on orbit. The obtained correlation between focusing and temperature is proven effective based on ground imaging and simulation testing.%The performance of space hyper spectral imager is severely affected by turbulent orbit temperature. Turbulence results in a defocus in the fore optical system of the imager. To address this problem, a focusing system is added. A number of simulation methods are applied on the fore optical system to study the relationship between temperature and focusing. In addition, this process is conducted to obtain a practical reference for focusing while the imager is flying on orbit. The obtained correlation between focusing and temperature is proven effective based on ground imaging and simulation testing.

  5. MICADO : The E-ELT adaptive optics imaging camera

    NARCIS (Netherlands)

    Davies, Richard; Ageorges, N.; Barl, L.; Bedin, L. R.; Bender, R.; Bernardi, P.; Chapron, F.; Clenet, Y.; Deep, A.; Deul, E.; Drost, M.; Eisenhauer, F.; Falomo, R.; Fiorentino, G.; Förster Schreiber, N. M.; Gendron, E.; Genzel, R.; Gratadour, D.; Greggio, L.; Grupp, F.; Held, E.; Herbst, T.; Hess, H.-J.; Hubert, Z.; Jahnke, K.; Kuijken, K.; Lutz, D.; Magrin, D.; Muschielok, B.; Navarro, R.; Noyola, E.; Paumard, T.; Piotto, G.; Ragazzoni, R.; Renzini, A.; Rousset, G.; Rix, H.-W.; Saglia, R.; Tacconi, L.; Thiel, M.; Tolstoy, E.; Trippe, S.; Tromp, N.; Valentijn, E. A.; Verdoes Kleijn, G.; Wegner, M.; McLean, I.S.; Ramsay, S.K.; Takami, H.


    MICADO is the adaptive optics imaging camera for the E-ELT. It has been designed and optimised to be mounted to the LGS-MCAO system MAORY, and will provide diffraction limited imaging over a wide (~1 arcmin) field of view. For initial operations, it can also be used with its own simpler AO module th

  6. A Multimodality Hybrid Gamma-Optical Camera for Intraoperative Imaging

    Directory of Open Access Journals (Sweden)

    John E. Lees


    Full Text Available The development of low profile gamma-ray detectors has encouraged the production of small field of view (SFOV hand-held imaging devices for use at the patient bedside and in operating theatres. Early development of these SFOV cameras was focussed on a single modality—gamma ray imaging. Recently, a hybrid system—gamma plus optical imaging—has been developed. This combination of optical and gamma cameras enables high spatial resolution multi-modal imaging, giving a superimposed scintigraphic and optical image. Hybrid imaging offers new possibilities for assisting clinicians and surgeons in localising the site of uptake in procedures such as sentinel node detection. The hybrid camera concept can be extended to a multimodal detector design which can offer stereoscopic images, depth estimation of gamma-emitting sources, and simultaneous gamma and fluorescence imaging. Recent improvements to the hybrid camera have been used to produce dual-modality images in both laboratory simulations and in the clinic. Hybrid imaging of a patient who underwent thyroid scintigraphy is reported. In addition, we present data which shows that the hybrid camera concept can be extended to estimate the position and depth of radionuclide distribution within an object and also report the first combined gamma and Near-Infrared (NIR fluorescence images.

  7. Perfect imaging in the optical domain using dielectric materials

    CERN Document Server

    Gabrielli, Lucas H; Lipson, Michal


    The promise of perfect imaging in the optical domain, where light can be imaged without aberrations and with ultra-high resolution, could revolutionize technology and nanofabrication [1, 2, 3, 4, 5, 6]. Recently it has been shown theoretically that perfect imaging can be achieved in a dielectric medium with spatially varying refractive index [7, 8]. The lens geometry is defined using transformation optics [9, 10, 11, 12, 13, 14, 15] for projecting a spherical space onto a real plane space, forming Maxwells fish eye [16, 17, 18, 19]. Most transformation optics demonstrations have been achieved for Euclidean spaces and in the microwave regime, due to ease of fabrication. Here we demonstrate a transformation to a non-Euclidean space [20] in the optical regime using silicon nanophotonic structures.

  8. Time-gated optical imaging through turbid media using stimulated Raman scattering: Studies on image contrast

    Indian Academy of Sciences (India)

    K Divakar Rao; H S Patel; B Jain; P K Gupta


    In this paper, we report the development of experimental set-up for timegated optical imaging through turbid media using stimulated Raman scattering. Our studies on the contrast of time-gated images show that for a given optical thickness, the image contrast is better for sample with lower scattering coefficient and higher physical thickness, and that the contrast improves with decreasing value of anisotropy parameters of the scatterers. These results are consistent with time-resolved Monte Carlo simulations.

  9. Digital image compression for a 2f multiplexing optical setup (United States)

    Vargas, J.; Amaya, D.; Rueda, E.


    In this work a virtual 2f multiplexing system was implemented in combination with digital image compression techniques and redundant information elimination. Depending on the image type to be multiplexed, a memory-usage saving of as much as 99% was obtained. The feasibility of the system was tested using three types of images, binary characters, QR codes, and grey level images. A multiplexing step was implemented digitally, while a demultiplexing step was implemented in a virtual 2f optical setup following real experimental parameters. To avoid cross-talk noise, each image was codified with a specially designed phase diffraction carrier that would allow the separation and relocation of the multiplexed images on the observation plane by simple light propagation. A description of the system is presented together with simulations that corroborate the method. The present work may allow future experimental implementations that will make use of all the parallel processing capabilities of optical systems.

  10. Integration of optical imaging with a small animal irradiator

    Energy Technology Data Exchange (ETDEWEB)

    Weersink, Robert A., E-mail: [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada and Techna Institute, University Health Network, 124-100 College Street, Toronto, Ontario M5G 1P5 (Canada); Ansell, Steve; Wang, An; Wilson, Graham [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Shah, Duoaud [Techna Institute, University Health Network, 124-100 College Street, Toronto, Ontario M5G 1P5 (Canada); Lindsay, Patricia E. [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9, Canada and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 1A1 (Canada); Jaffray, David A. [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Techna Institute, University Health Network, 124-100 College Street, Toronto, Ontario M5G 1P5 (Canada); Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 1A1 (Canada); Ontario Cancer Institute, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5S 1A1 (Canada)


    Purpose: The authors describe the integration of optical imaging with a targeted small animal irradiator device, focusing on design, instrumentation, 2D to 3D image registration, 2D targeting, and the accuracy of recovering and mapping the optical signal to a 3D surface generated from the cone-beam computed tomography (CBCT) imaging. The integration of optical imaging will improve targeting of the radiation treatment and offer longitudinal tracking of tumor response of small animal models treated using the system. Methods: The existing image-guided small animal irradiator consists of a variable kilovolt (peak) x-ray tube mounted opposite an aSi flat panel detector, both mounted on a c-arm gantry. The tube is used for both CBCT imaging and targeted irradiation. The optical component employs a CCD camera perpendicular to the x-ray treatment/imaging axis with a computer controlled filter for spectral decomposition. Multiple optical images can be acquired at any angle as the gantry rotates. The optical to CBCT registration, which uses a standard pinhole camera model, was modeled and tested using phantoms with markers visible in both optical and CBCT images. Optically guided 2D targeting in the anterior/posterior direction was tested on an anthropomorphic mouse phantom with embedded light sources. The accuracy of the mapping of optical signal to the CBCT surface was tested using the same mouse phantom. A surface mesh of the phantom was generated based on the CBCT image and optical intensities projected onto the surface. The measured surface intensity was compared to calculated surface for a point source at the actual source position. The point-source position was also optimized to provide the closest match between measured and calculated intensities, and the distance between the optimized and actual source positions was then calculated. This process was repeated for multiple wavelengths and sources. Results: The optical to CBCT registration error was 0.8 mm. Two

  11. MR imaging of optic neuritis using short TI IR

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Kohichi; Uehara, Masako; Ashikaga, Ryuichirou; Inoue, Masaaki; Shindou, Hiroshi; Mabuchi, Nobuhisa; Yoshioka, Hiroyasu; Hamada, Tatsumi; Ishida, Osamu (Kinki Univ., Osaka (Japan). School of Medicine)


    We evaluated the ability of MRI using short TI inversion recovery (STIR) to diagnose optic neuritis. Eleven patients with previous or recent attack of optic neuritis were studied with MRI at 0.5 tesla. STIR images revealed high signal regions in 7 of 12 symptomatic and 5 of 10 asymptomatic nerves. Three of five asymptomatic nerves with high intensity were pertinent to the cases with past attack and seemed to reflect the demyelinating change. The other two nerves were pertinent to the cases without past attack and seemed to show occult lesions. We consider that STIR is useful in detection of optic nerve lesions associated with optic neuritis. (author).

  12. Digital optical cellular image processor (DOCIP) - Experimental implementation (United States)

    Huang, K.-S.; Sawchuk, A. A.; Jenkins, B. K.; Chavel, P.; Wang, J.-M.; Weber, A. G.; Wang, C.-H.; Glaser, I.


    We demonstrate experimentally the concept of the digital optical cellular image processor architecture by implementing one processing element of a prototype optical computer that includes a 54-gate processor, an instruction decoder, and electronic input-output interfaces. The processor consists of a two-dimensional (2-D) array of 54 optical logic gates implemented by use of a liquid-crystal light valve and a 2-D array of 53 subholograms to provide interconnections between gates. The interconnection hologram is fabricated by a computer-controlled optical system.

  13. High-resolution in-depth imaging of optically cleared thick samples using an adaptive SPIM (United States)

    Masson, Aurore; Escande, Paul; Frongia, Céline; Clouvel, Grégory; Ducommun, Bernard; Lorenzo, Corinne


    Today, Light Sheet Fluorescence Microscopy (LSFM) makes it possible to image fluorescent samples through depths of several hundreds of microns. However, LSFM also suffers from scattering, absorption and optical aberrations. Spatial variations in the refractive index inside the samples cause major changes to the light path resulting in loss of signal and contrast in the deepest regions, thus impairing in-depth imaging capability. These effects are particularly marked when inhomogeneous, complex biological samples are under study. Recently, chemical treatments have been developed to render a sample transparent by homogenizing its refractive index (RI), consequently enabling a reduction of scattering phenomena and a simplification of optical aberration patterns. One drawback of these methods is that the resulting RI of cleared samples does not match the working RI medium generally used for LSFM lenses. This RI mismatch leads to the presence of low-order aberrations and therefore to a significant degradation of image quality. In this paper, we introduce an original optical-chemical combined method based on an adaptive SPIM and a water-based clearing protocol enabling compensation for aberrations arising from RI mismatches induced by optical clearing methods and acquisition of high-resolution in-depth images of optically cleared complex thick samples such as Multi-Cellular Tumour Spheroids.

  14. Optical image hiding based on computational ghost imaging (United States)

    Wang, Le; Zhao, Shengmei; Cheng, Weiwen; Gong, Longyan; Chen, Hanwu


    Imaging hiding schemes play important roles in now big data times. They provide copyright protections of digital images. In the paper, we propose a novel image hiding scheme based on computational ghost imaging to have strong robustness and high security. The watermark is encrypted with the configuration of a computational ghost imaging system, and the random speckle patterns compose a secret key. Least significant bit algorithm is adopted to embed the watermark and both the second-order correlation algorithm and the compressed sensing (CS) algorithm are used to extract the watermark. The experimental and simulation results show that the authorized users can get the watermark with the secret key. The watermark image could not be retrieved when the eavesdropping ratio is less than 45% with the second-order correlation algorithm, whereas it is less than 20% with the TVAL3 CS reconstructed algorithm. In addition, the proposed scheme is robust against the 'salt and pepper' noise and image cropping degradations.

  15. Imaging photothermal microscopy for absorption measurements of optical coatings

    Institute of Scientific and Technical Information of China (English)

    Chunxian Tao; Yuanan Zhao; Hongbo He; Dawei Li; Jianda Shao; Zhengxiu Fan


    @@ For absorption measurement of large-aperture optical coatings, a novel method of imaging photothermal microscopy based on image lock-in technique is presented.Detailed theoretical analysis and numerical calculation are made based on the image photothermal technique.The feasibility of this imaging method is proved through the coincidence between the theoretical results of single spot method and multi-channel method.The measuring speed of this imaging method can be increased hundreds of times compared with that of the raster scanning.This technique can expand the applications of photothermal technique.

  16. Stochastic Optics: A Scattering Mitigation Framework for Radio Interferometric Imaging

    CERN Document Server

    Johnson, Michael D


    Just as turbulence in the Earth's atmosphere can severely limit the angular resolution of optical telescopes, turbulence in the ionized interstellar medium fundamentally limits the resolution of radio telescopes. We present a scattering mitigation framework for radio imaging with very long baseline interferometry (VLBI) that partially overcomes this limitation. Our framework, "stochastic optics," derives from a simplification of strong interstellar scattering to separate small-scale ("diffractive") effects from large-scale ("refractive") effects, thereby separating deterministic and random contributions to the scattering. Stochastic optics extends traditional synthesis imaging by simultaneously reconstructing an unscattered image and its refractive perturbations. Its advantages over direct imaging come from utilizing the many deterministic properties of the scattering -- such as the time-averaged "blurring," polarization independence, and the deterministic evolution in frequency and time -- while still accoun...

  17. Diffusion MR Imaging of Postoperative Bilateral Acute Ischemic Optic Neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Kannan, Anusha; Srinivasan, Sivasubramanian [Khoo Teck Puat Hospital, Singapore (Singapore)


    We read with great interest, the case report on ischemic optic neuropathy (1). We would like to add a few points concerning the blood supply of the optic nerve and the correlation with the development of post-operative ischemic neuropathy. Actually, the perioperative or post-operative vision loss (postoperative ischemic neuropathy) is most likely due to ischemic optic neuropathy. Ischemic optic neuropathy (2) is classified as an anterior ischemic optic neuropathy (AION) and posterior ischemic optic neuropathy (PION). This classification is based on the fact that blood supply (2) to the anterior segment of the optic nerve (part of the optic nerve in the scleral canal and the optic disc) is supplied by short posterior ciliary vessels or anastamotic ring branches around the optic nerve. The posterior part of the optic canal is relatively less perfused, and is supplied by ophthalmic artery and central fibres are perfused by a central retinal artery. So, in the post-operative period, the posterior part of the optic nerve is more vulnerable for ischemia, especially, after major surgeries (3), one of the theories being hypotension or anaemia (2) and resultant decreased perfusion. The onset of PION is slower than the anterior ischemic optic neuropathy. AION on the other hand, is usually spontaneous (idiopathic) or due to arteritis, and is usually sudden in its onset. The reported case is most likely a case of PION. The role of imaging, especially the diffusion weighted magnetic resonance imaging, is very important because the ophthalmoscopic findings in early stages of PION is normal, and it may delay the diagnosis. On the other hand, edema of the disc is usually seen in the early stages of AION.

  18. Electro-Optical Imaging Microscopy of Dye-Doped Artificial Lipidic Membranes (United States)

    Hajj, Bassam; De Reguardati, Sophie; Hugonin, Loïc; Le Pioufle, Bruno; Osaki, Toshihisa; Suzuki, Hiroaki; Takeuchi, Shoji; Mojzisova, Halina; Chauvat, Dominique; Zyss, Joseph


    Artificial lipidic bilayers are widely used as a model for the lipid matrix in biological cell membranes. We use the Pockels electro-optical effect to investigate the properties of an artificial lipidic membrane doped with nonlinear molecules in the outer layer. We report here what is believed to be the first electro-optical Pockels signal and image from such a membrane. The electro-optical dephasing distribution within the membrane is imaged and the signal is shown to be linear as a function of the applied voltage. A theoretical analysis taking into account the statistical orientation distribution of the inserted dye molecules allows us to estimate the doped membrane nonlinearity. Ongoing extensions of this work to living cell membranes are discussed. PMID:19948120

  19. Accuracy requirements of optical linear algebra processors in adaptive optics imaging systems (United States)

    Downie, John D.


    A ground-based adaptive optics imaging telescope system attempts to improve image quality by detecting and correcting for atmospherically induced wavefront aberrations. The required control computations during each cycle will take a finite amount of time. Longer time delays result in larger values of residual wavefront error variance since the atmosphere continues to change during that time. Thus an optical processor may be well-suited for this task. This paper presents a study of the accuracy requirements in a general optical processor that will make it competitive with, or superior to, a conventional digital computer for the adaptive optics application. An optimization of the adaptive optics correction algorithm with respect to an optical processor's degree of accuracy is also briefly discussed.

  20. 3D Imaging of Nanoparticle Distribution in Biological Tissue by Laser-Induced Breakdown Spectroscopy (United States)

    Gimenez, Y.; Busser, B.; Trichard, F.; Kulesza, A.; Laurent, J. M.; Zaun, V.; Lux, F.; Benoit, J. M.; Panczer, G.; Dugourd, P.; Tillement, O.; Pelascini, F.; Sancey, L.; Motto-Ros, V.


    Nanomaterials represent a rapidly expanding area of research with huge potential for future medical applications. Nanotechnology indeed promises to revolutionize diagnostics, drug delivery, gene therapy, and many other areas of research. For any biological investigation involving nanomaterials, it is crucial to study the behavior of such nano-objects within tissues to evaluate both their efficacy and their toxicity. Here, we provide the first account of 3D label-free nanoparticle imaging at the entire-organ scale. The technology used is known as laser-induced breakdown spectroscopy (LIBS) and possesses several advantages such as speed of operation, ease of use and full compatibility with optical microscopy. We then used two different but complementary approaches to achieve 3D elemental imaging with LIBS: a volume reconstruction of a sliced organ and in-depth analysis. This proof-of-concept study demonstrates the quantitative imaging of both endogenous and exogenous elements within entire organs and paves the way for innumerable applications.

  1. Macro-/micro-environment-sensitive chemosensing and biological imaging. (United States)

    Yang, Zhigang; Cao, Jianfang; He, Yanxia; Yang, Jung Ho; Kim, Taeyoung; Peng, Xiaojun; Kim, Jong Seung


    Environment-related parameters, including viscosity, polarity, temperature, hypoxia, and pH, play pivotal roles in controlling the physical or chemical behaviors of local molecules. In particular, in a biological environment, such factors predominantly determine the biological properties of the local environment or reflect corresponding status alterations. Abnormal changes in these factors would cause cellular malfunction or become a hallmark of the occurrence of severe diseases. Therefore, in recent years, they have increasingly attracted research interest from the fields of chemistry and biological chemistry. With the emergence of fluorescence sensing and imaging technology, several fluorescent chemosensors have been designed to respond to such parameters and to further map their distributions and variations in vitro/in vivo. In this work, we have reviewed a number of various environment-responsive chemosensors related to fluorescent recognition of viscosity, polarity, temperature, hypoxia, and pH that have been reported thus far.

  2. Ultrathin Optics for Low-Profile Innocuous Imager

    Energy Technology Data Exchange (ETDEWEB)

    Boye, Robert R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photonic Microsystems Technologies; Brady, Gregory Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Photonic Microsystems Technologies; Nelson, Cynthia Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Systems Engineering I; Briggs, Ronald D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Integrated Microdevice Systems; Jared, Bradley Howell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Prototyping S& T; Warren, Mial E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Microsystems Partnerships


    This project demonstrates the feasibility of a novel imager with a thickness measured in microns rather than inches. Traditional imaging systems, i.e. cameras, cannot provide both the necessary resolution and innocuous form factor required in many data acquisition applications. Designing an imaging system with an extremely thin form factor (less than 1 mm) immediately presents several technical challenges. For instance, the thickness of the optical lens must be reduced drastically from currently available lenses. Additionally, the image circle is reduced by a factor equal to the reduction in focal length. This translates to fewer detector pixels across the image. To reduce the optical total track requires the use of specialized micro-optics and the required resolution necessitates the use of a new imaging modality. While a single thin imager will not produce the desired output, several thin imagers can be multiplexed and their low resolution (LR) outputs used together in post-processing to produce a high resolution (HR) image. The utility of an Iterative Back Projection (IBP) algorithm has been successfully demonstrated for performing the required post-processing. Advanced fabrication of a thin lens was also demonstrated and experimental results using this lens as well as commercially available lenses are presented.

  3. Red emitting neutral fluorescent glycoconjugates for membrane optical imaging. (United States)

    Redon, Sébastien; Massin, Julien; Pouvreau, Sandrine; De Meulenaere, Evelien; Clays, Koen; Queneau, Yves; Andraud, Chantal; Girard-Egrot, Agnès; Bretonnière, Yann; Chambert, Stéphane


    A family of neutral fluorescent probes was developed, mimicking the overall structure of natural glycolipids in order to optimize their membrane affinity. Nonreducing commercially available di- or trisaccharidic structures were connected to a push-pull chromophore based on dicyanoisophorone electron-accepting group, which proved to fluoresce in the red region with a very large Stokes shift. This straightforward synthetic strategy brought structural variations to a series of probes, which were studied for their optical, biophysical, and biological properties. The insertion properties of the different probes into membranes were evaluated on a model system using the Langmuir monolayer balance technique. Confocal fluorescence microscopy performed on muscle cells showed completely different localizations and loading efficiencies depending on the structure of the probes. When compared to the commercially available ANEPPS, a family of commonly used membrane imaging dyes, the most efficient probes showed a similar brightness, but a sharper pattern was observed. According to this study, compounds bearing one chromophore, a limited size of the carbohydrate moiety, and an overall rod-like shape gave the best results.

  4. Biological object recognition in μ-radiography images (United States)

    Prochazka, A.; Dammer, J.; Weyda, F.; Sopko, V.; Benes, J.; Zeman, J.; Jandejsek, I.


    This study presents an applicability of real-time microradiography to biological objects, namely to horse chestnut leafminer, Cameraria ohridella (Insecta: Lepidoptera, Gracillariidae) and following image processing focusing on image segmentation and object recognition. The microradiography of insects (such as horse chestnut leafminer) provides a non-invasive imaging that leaves the organisms alive. The imaging requires a high spatial resolution (micrometer scale) radiographic system. Our radiographic system consists of a micro-focus X-ray tube and two types of detectors. The first is a charge integrating detector (Hamamatsu flat panel), the second is a pixel semiconductor detector (Medipix2 detector). The latter allows detection of single quantum photon of ionizing radiation. We obtained numerous horse chestnuts leafminer pupae in several microradiography images easy recognizable in automatic mode using the image processing methods. We implemented an algorithm that is able to count a number of dead and alive pupae in images. The algorithm was based on two methods: 1) noise reduction using mathematical morphology filters, 2) Canny edge detection. The accuracy of the algorithm is higher for the Medipix2 (average recall for detection of alive pupae =0.99, average recall for detection of dead pupae =0.83), than for the flat panel (average recall for detection of alive pupae =0.99, average recall for detection of dead pupae =0.77). Therefore, we conclude that Medipix2 has lower noise and better displays contours (edges) of biological objects. Our method allows automatic selection and calculation of dead and alive chestnut leafminer pupae. It leads to faster monitoring of the population of one of the world's important insect pest.

  5. Laser-matter structuration of optical and biological materials

    Energy Technology Data Exchange (ETDEWEB)

    Hallo, L., E-mail: [CELIA, Universite Bordeaux 1 (France); Mezel, C., E-mail: [CELIA, Universite Bordeaux 1 (France); CEA Le Ripault, 37260 Monts (France); Guillemot, F., E-mail: [UMR 577 INSERM, Universite Bordeaux 2 (France); Chimier, B., E-mail: [CELIA, Universite Bordeaux 1 (France); Bourgeade, A., E-mail: [CEA-CESTA, Le Barp (France); Regan, C., E-mail: [CELIA, Universite Bordeaux 1 (France); Duchateau, G., E-mail: [CELIA, Universite Bordeaux 1 (France); Souquet, A., E-mail: [UMR 577 INSERM, Universite Bordeaux 2 (France); Hebert, D., E-mail: [CEA-CESTA, Le Barp (France)


    Highlights: Black-Right-Pointing-Pointer In this study we model nanomaterial structuring. Black-Right-Pointing-Pointer The laser energy deposition is discussed first. Black-Right-Pointing-Pointer Full and approximate models are discussed. Black-Right-Pointing-Pointer Dynamic material response is addressed via hydrodynamics. Black-Right-Pointing-Pointer Sild effects are accounted for - Abstract: Interaction of ultrafast laser, i.e. from the femtosecond (fs) to the nanosecond (ns) regime, with initially transparent matter may produce very high energy density hot spots in the bulk as well as at the material surface, depending on focusing conditions. In the fs regime, absorption is due to ionisation of the dielectric, which enables absorption process to begin, and then hydrodynamic to take place. In the ns regime both absorption and hydrodynamic are coupled to each other, which complexifies considerably the comprehension but matter structuration looks similar. A numerical tool including solution of 3D Maxwell equations and a rate equation for free electrons is first compared to some available simple models of laser energy absorption. Then, subsequent material deformation, i.e. structuration, is determined by solving hydrodynamic equations, including or not solid behaviour. We show that nature of the final structures strongly depends on the amount of deposited energy and on the shape of the absorption zone. Then we address some problems related to laser-matter structuration of optical and biological materials in the fs, ps and ns regimes.

  6. Chemical shift selective magnetic resonance imaging of the optic nerve in patients with acute optic neuritis

    DEFF Research Database (Denmark)

    Larsson, H B; Thomsen, C; Frederiksen, J;


    Optic neuritis is often the first manifestation of multiple sclerosis (MS). Sixteen patients with acute optic neuritis and one patient with benign intracranial hypertension (BIH) were investigated by magnetic resonance imaging, using a chemical shift selective double spin echo sequence. In 3...... were only shown in 3/16 (19%) of the patients with optic neuritis. Nevertheless, the presented chemical shift selective double spin echo sequence may be of great value for detection of retrobulbar lesions....

  7. An improved image reconstruction method for optical intensity correlation Imaging (United States)

    Gao, Xin; Feng, Lingjie; Li, Xiyu


    The intensity correlation imaging method is a novel kind of interference imaging and it has favorable prospects in deep space recognition. However, restricted by the low detecting signal-to-noise ratio (SNR), it's usually very difficult to obtain high-quality image of deep space object like high-Earth-orbit (HEO) satellite with existing phase retrieval methods. In this paper, based on the priori intensity statistical distribution model of the object and characteristics of measurement noise distribution, an improved method of Prior Information Optimization (PIO) is proposed to reduce the ambiguous images and accelerate the phase retrieval procedure thus realizing fine image reconstruction. As the simulations and experiments show, compared to previous methods, our method could acquire higher-resolution images with less error in low SNR condition.

  8. Compressive Fluorescence Microscopy for Biological and Hyperspectral Imaging

    CERN Document Server

    Studer, Vincent; Chahid, Makhlad; Moussavi, Hamed; Candes, Emmanuel; Dahan, Maxime


    The mathematical theory of compressed sensing (CS) asserts that one can acquire signals from measurements whose rate is much lower than the total bandwidth. Whereas the CS theory is now well developed, challenges concerning hardware implementations of CS-based acquisition devices---especially in optics---have only started being addressed. This paper presents an implementation of compressive sensing in fluorescence microscopy and its applications to biomedical imaging. Our CS microscope combines a dynamic structured wide-field illumination and a fast and sensitive single-point fluorescence detection to enable reconstructions of images of fluorescent beads, cells and tissues with undersampling ratios (between the number of pixels and number of measurements) up to 32. We further demonstrate a hyperspectral mode and record images with 128 spectral channels and undersampling ratios up to 64, illustrating the potential benefits of CS acquisition for higher dimensional signals which typically exhibits extreme redund...

  9. The use of contrast agent for imaging biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Dammer, J; Sopko, V; Jakubek, J [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Weyda, F, E-mail: [Biological center of the Academy of Sciences of the Czech Republic, Institute of Entomology, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic)


    The technique of X-ray transmission imaging has been available for over a century and is still among the fastest and easiest approaches to the studies of internal structure of biological samples. Recent advances in semiconductor technology have led to the development of new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Semiconductor pixel detectors seem to be specially promising; compared to the film technique, they provide single-quantum and real-time digital information about the objects being studied. We describe the recently developed radiographic apparatus, equipped with Medipix2 semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube (micro- or nano-focus FeinFocus). Thanks to the wide dynamic range of the Medipix2 detector and its high spatial resolution better than 1{mu}m, the setup is particularly suitable for radiographic imaging of small biological samples, including in-vivo observations with contrast agent (Optiray). Along with the description of the apparatus we provide examples of the use iodine contrast agent as a tracer in various insects as model organisms. The motivation of our work is to develop our imaging techniques as non-destructive and non-invasive. Microradiographic imaging helps detect organisms living in a not visible environment, visualize the internal biological processes and also to resolve the details of their body (morphology). Tiny live insects are an ideal object for our studies.

  10. Reticle defect sizing of optical proximity correction defects using SEM imaging and image analysis techniques (United States)

    Zurbrick, Larry S.; Wang, Lantian; Konicek, Paul; Laird, Ellen R.


    Sizing of programmed defects on optical proximity correction (OPC) feature sis addressed using high resolution scanning electron microscope (SEM) images and image analysis techniques. A comparison and analysis of different sizing methods is made. This paper addresses the issues of OPC defect definition and discusses the experimental measurement results obtained by SEM in combination with image analysis techniques.

  11. Improving resolution of optical coherence tomography for imaging of microstructures (United States)

    Shen, Kai; Lu, Hui; Wang, James H.; Wang, Michael R.


    Multi-frame superresolution technique has been used to improve the lateral resolution of spectral domain optical coherence tomography (SD-OCT) for imaging of 3D microstructures. By adjusting the voltages applied to ? and ? galvanometer scanners in the measurement arm, small lateral imaging positional shifts have been introduced among different C-scans. Utilizing the extracted ?-? plane en face image frames from these specially offset C-scan image sets at the same axial position, we have reconstructed the lateral high resolution image by the efficient multi-frame superresolution technique. To further improve the image quality, we applied the latest K-SVD and bilateral total variation denoising algorithms to the raw SD-OCT lateral images before and along with the superresolution processing, respectively. The performance of the SD-OCT of improved lateral resolution is demonstrated by 3D imaging a microstructure fabricated by photolithography and a double-layer microfluidic device.

  12. Development of Biological Movement Recognition by Interaction between Active Basis Model and Fuzzy Optical Flow Division

    Directory of Open Access Journals (Sweden)

    Bardia Yousefi


    Full Text Available Following the study on computational neuroscience through functional magnetic resonance imaging claimed that human action recognition in the brain of mammalian pursues two separated streams, that is, dorsal and ventral streams. It follows up by two pathways in the bioinspired model, which are specialized for motion and form information analysis (Giese and Poggio 2003. Active basis model is used to form information which is different from orientations and scales of Gabor wavelets to form a dictionary regarding object recognition (human. Also biologically movement optic-flow patterns utilized. As motion information guides share sketch algorithm in form pathway for adjustment plus it helps to prevent wrong recognition. A synergetic neural network is utilized to generate prototype templates, representing general characteristic form of every class. Having predefined templates, classifying performs based on multitemplate matching. As every human action has one action prototype, there are some overlapping and consistency among these templates. Using fuzzy optical flow division scoring can prevent motivation for misrecognition. We successfully apply proposed model on the human action video obtained from KTH human action database. Proposed approach follows the interaction between dorsal and ventral processing streams in the original model of the biological movement recognition. The attained results indicate promising outcome and improvement in robustness using proposed approach.

  13. Ex vivo imaging of human thyroid pathology using integrated optical coherence tomography and optical coherence microscopy (United States)

    Zhou, Chao; Wang, Yihong; Aguirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.


    We evaluate the feasibility of optical coherence tomography (OCT) and optical coherence microscopy (OCM) for imaging of benign and malignant thyroid lesions ex vivo using intrinsic optical contrast. 34 thyroid gland specimens are imaged from 17 patients, covering a spectrum of pathology ranging from normal thyroid to benign disease/neoplasms (multinodular colloid goiter, Hashimoto's thyroiditis, and follicular adenoma) and malignant thyroid tumors (papillary carcinoma and medullary carcinoma). Imaging is performed using an integrated OCT and OCM system, with tumor cells, can be identified from OCT and OCM images and are clearly differentiable from normal or benign thyroid tissues. With further development of needle-based imaging probes, OCT and OCM could be promising techniques to use for the screening of thyroid nodules and to improve the diagnostic specificity of fine needle aspiration evaluation.

  14. AFM imaging of natural optical structures (United States)

    Dallaeva, Dinara; Tománek, Pavel; Prokopyeva, Elena; Kaspar, Pavel; Grmela, Lubomír.; Škarvada, Pavel


    The colors of some living organisms assosiated with the surface structure. Irridesence butterfly wings is an example of such coloration. Optical effects such as interference, diffraction, polarization are responsible for physical colors appearance. Alongside with amazing beauty this structure represent interest for design of optical devices. Here we report the results of morphology investigation by atomic force microscopy. The difference in surface structure of black and blue wings areas is clearly observed. It explains the angle dependence of the wing blue color, since these micrometer and sub-micrometer quasiperiodical structures could control the light propagation, absorption and reflection.

  15. Optical design and characterization of an advanced computational imaging system (United States)

    Shepard, R. Hamilton; Fernandez-Cull, Christy; Raskar, Ramesh; Shi, Boxin; Barsi, Christopher; Zhao, Hang


    We describe an advanced computational imaging system with an optical architecture that enables simultaneous and dynamic pupil-plane and image-plane coding accommodating several task-specific applications. We assess the optical requirement trades associated with custom and commercial-off-the-shelf (COTS) optics and converge on the development of two low-cost and robust COTS testbeds. The first is a coded-aperture programmable pixel imager employing a digital micromirror device (DMD) for image plane per-pixel oversampling and spatial super-resolution experiments. The second is a simultaneous pupil-encoded and time-encoded imager employing a DMD for pupil apodization or a deformable mirror for wavefront coding experiments. These two testbeds are built to leverage two MIT Lincoln Laboratory focal plane arrays - an orthogonal transfer CCD with non-uniform pixel sampling and on-chip dithering and a digital readout integrated circuit (DROIC) with advanced on-chip per-pixel processing capabilities. This paper discusses the derivation of optical component requirements, optical design metrics, and performance analyses for the two testbeds built.

  16. Optical and Digital Microscopic Imaging Techniques and Applications in Pathology

    Directory of Open Access Journals (Sweden)

    Xiaodong Chen


    Full Text Available The conventional optical microscope has been the primary tool in assisting pathological examinations. The modern digital pathology combines the power of microscopy, electronic detection, and computerized analysis. It enables cellular-, molecular-, and genetic-imaging at high efficiency and accuracy to facilitate clinical screening and diagnosis. This paper first reviews the fundamental concepts of microscopic imaging and introduces the technical features and associated clinical applications of optical microscopes, electron microscopes, scanning tunnel microscopes, and fluorescence microscopes. The interface of microscopy with digital image acquisition methods is discussed. The recent developments and future perspectives of contemporary microscopic imaging techniques such as three-dimensional and in vivo imaging are analyzed for their clinical potentials.

  17. Analog signal processing for optical coherence imaging systems (United States)

    Xu, Wei

    Optical coherence tomography (OCT) and optical coherence microscopy (OCM) are non-invasive optical coherence imaging techniques, which enable micron-scale resolution, depth resolved imaging capability. Both OCT and OCM are based on Michelson interferometer theory. They are widely used in ophthalmology, gastroenterology and dermatology, because of their high resolution, safety and low cost. OCT creates cross sectional images whereas OCM obtains en face images. In this dissertation, the design and development of three increasingly complicated analog signal processing (ASP) solutions for optical coherence imaging are presented. The first ASP solution was implemented for a time domain OCT system with a Rapid Scanning Optical Delay line (RSOD)-based optical signal modulation and logarithmic amplifier (Log amp) based demodulation. This OCT system can acquire up to 1600 A-scans per second. The measured dynamic range is 106dB at 200A-scan per second. This OCT signal processing electronics includes an off-the-shelf filter box with a Log amp circuit implemented on a PCB board. The second ASP solution was developed for an OCM system with synchronized modulation and demodulation and compensation for interferometer phase drift. This OCM acquired micron-scale resolution, high dynamic range images at acquisition speeds up to 45,000 pixels/second. This OCM ASP solution is fully custom designed on a perforated circuit board. The third ASP solution was implemented on a single 2.2 mm x 2.2 mm complementary metal oxide semiconductor (CMOS) chip. This design is expandable to a multiple channel OCT system. A single on-chip CMOS photodetector and ASP channel was used for coherent demodulation in a time domain OCT system. Cross-sectional images were acquired with a dynamic range of 76dB (limited by photodetector responsivity). When incorporated with a bump-bonded InGaAs photodiode with higher responsivity, the expected dynamic range is close to 100dB.

  18. Optical double-image cryptography based on diffractive imaging with a laterally-translated phase grating. (United States)

    Chen, Wen; Chen, Xudong; Sheppard, Colin J R


    In this paper, we propose a method using structured-illumination-based diffractive imaging with a laterally-translated phase grating for optical double-image cryptography. An optical cryptosystem is designed, and multiple random phase-only masks are placed in the optical path. When a phase grating is laterally translated just before the plaintexts, several diffraction intensity patterns (i.e., ciphertexts) can be correspondingly obtained. During image decryption, an iterative retrieval algorithm is developed to extract plaintexts from the ciphertexts. In addition, security and advantages of the proposed method are analyzed. Feasibility and effectiveness of the proposed method are demonstrated by numerical simulation results.

  19. THz near-field imaging of biological tissues employing synchrotronradiation

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Ulrich; Holldack, Karsten; Martin, Michael C.; Fried,Daniel


    Terahertz scanning near-field infrared microscopy (SNIM) below 1 THz is demonstrated. The near-field technique benefits from the broadband and highly brilliant coherent synchrotron radiation (CSR) from an electron storage ring and from a detection method based on locking onto the intrinsic time structure of the synchrotron radiation. The scanning microscope utilizes conical wave guides as near-field probes with apertures smaller than the wavelength. Different cone approaches have been investigated to obtain maximum transmittance. Together with a Martin-Puplett spectrometer the set-up enables spectroscopic mapping of the transmittance of samples well below the diffraction limit. Spatial resolution down to about lambda/40 at 2 wavenumbers (0.06 THz) is derived from the transmittance spectra of the near-field probes. The potential of the technique is exemplified by imaging biological samples. Strongly absorbing living leaves have been imaged in transmittance with a spatial resolution of 130 mu-m at about 12 wave numbers (0.36 THz). The THz near-field images reveal distinct structural differences of leaves from different plants investigated. The technique presented also allows spectral imaging of bulky organic tissues. Human teeth samples of various thicknesses have been imaged between 2 and 20 wavenumbers (between 0.06and 0.6 THz). Regions of enamel and dentin within tooth samples are spatially and spectrally resolved, and buried caries lesions are imaged through both the outer enamel and into the underlying dentin.

  20. CT guided diffuse optical tomography for breast cancer imaging (United States)

    Baikejiang, Reheman; Zhang, Wei; Zhu, Dianwen; Li, Changqing


    Diffuse optical tomography (DOT) has attracted attentions in the last two decades due to its intrinsic sensitivity in imaging chromophores of tissues such as blood, water, and lipid. However, DOT has not been clinically accepted yet due to its low spatial resolution caused by strong optical scattering in tissues. Structural guidance provided by an anatomical imaging modality enhances the DOT imaging substantially. Here, we propose a computed tomography (CT) guided multispectral DOT imaging system for breast cancer detection. To validate its feasibility, we have built a prototype DOT imaging system which consists of a laser at wavelengths of 650 and an electron multiplying charge coupled device (EMCCD) camera. We have validated the CT guided DOT reconstruction algorithms with numerical simulations and phantom experiments, in which different imaging setup parameters, such as projection number of measurements, the width of measurement patch, have been investigated. Our results indicate that an EMCCD camera with air cooling is good enough for the transmission mode DOT imaging. We have also found that measurements at six projections are sufficient for DOT to reconstruct the optical targets with 4 times absorption contrast when the CT guidance is applied. Finally, we report our effort and progress on the integration of the multispectral DOT imaging system into a breast CT scanner.

  1. Driving micro-optical imaging systems towards miniature camera applications (United States)

    Brückner, Andreas; Duparré, Jacques; Dannberg, Peter; Leitel, Robert; Bräuer, Andreas


    Up to now, multi channel imaging systems have been increasingly studied and approached from various directions in the academic domain due to their promising large field of view at small system thickness. However, specific drawbacks of each of the solutions prevented the diffusion into corresponding markets so far. Most severe problems are a low image resolution and a low sensitivity compared to a conventional single aperture lens besides the lack of a cost-efficient method of fabrication and assembly. We propose a microoptical approach to ultra-compact optics for real-time vision systems that are inspired by the compound eyes of insects. The demonstrated modules achieve a VGA resolution with 700x550 pixels within an optical package of 6.8mm x 5.2mm and a total track length of 1.4mm. The partial images that are separately recorded within different optical channels are stitched together to form a final image of the whole field of view by means of image processing. These software tools allow to correct the distortion of the individual partial images so that the final image is also free of distortion. The so-called electronic cluster eyes are realized by state-of-the-art microoptical fabrication techniques and offer a resolution and sensitivity potential that makes them suitable for consumer, machine vision and medical imaging applications.

  2. Imaging Biological Systems using Dielectric Near-Field Microscopy (United States)

    Brown, Keith; Issadore, David; Hunt, Tom; Westervelt, Robert


    We have developed a dielectric spectrometer for use on biological systems. The spectrum of dielectric response to RF electric fields is analogous to color as an optical response. Measurement of the dielectric spectrum from ˜ 10 kHz to ˜ 3 GHz will reveal information about the structure and conditions of protein solutions, protein crystals and biological tissues. We designed and built a system to test biological samples in a microfluidic chamber mounted on a circuit board. The apparatus measures the RF dielectric spectrum directly, or by analyzing the pulse response in the time domain. We have constructed several versions of the hardware for sensitive capacitive measurements, including two types of capacitive bridges, and a transmission line, incorporating precision electronics and local generation of pulses. A goal is to scale the system down and implement many dielectric spectrometers as an array of pixels on a CMOS chip for dielectric near-field microscopy of biological samples. This work made possible by NSEC NSF grant PHY-0117795 and the NCI MIT-Harvard CCNE.

  3. Acoustic-optical imaging without immersion (United States)

    Liu, H.


    System using membraneous end wall of Bragg cell to separate test specimen from acoustic transmission medium, operates in real time and uses readily available optical components. System can be easily set up and maintained by people with little or no training in holography.

  4. Design and manufacture of imaging time-of-propagation optics (United States)

    Albrecht, Mike; Fast, James; Schwartz, Alan


    There are several challenges associated with the design and manufacture of the optics required for the imaging time-of- propagation detector constructed for the Belle II particle physics experiment. This detector uses Cherenkov light radiated in quartz bars to identify subatomic particles: pions, kaons, and protons. The optics are physically large (125 cm x 45 cm x 2 cm bars and 45 cm x 10 cm x 5 cm prisms), all surfaces are optically polished, and there is very little allowance for chamfers or surface defects. In addition to the optical challenges, there are several logistical and handling challenges associated with measuring, assembling, cleaning, packaging, and shipping these delicate precision optics. This paper describes a collaborative effort between Pacific Northwest National Laboratory, the University of Cincinnati, and ZYGO Corporation for the design and manufacture of 48 fused silica optics (30 bars and 18 prisms) for the iTOP Detector. Details of the iTOP detector design that drove the challenging optical requirements are provided, along with material selection considerations. Since the optics are so large, precise, and delicate, special care had to be given to the selection of a manufacturing process capable of achieving the challenging optical and surface defect requirements on such large and high-aspect-ratio (66:1) components. A brief update on the current status and performance of these optics is also provided.

  5. High-resolution retinal imaging using adaptive optics and Fourier-domain optical coherence tomography (United States)

    Olivier, Scot S.; Werner, John S.; Zawadzki, Robert J.; Laut, Sophie P.; Jones, Steven M.


    This invention permits retinal images to be acquired at high speed and with unprecedented resolution in three dimensions (4.times.4.times.6 .mu.m). The instrument achieves high lateral resolution by using adaptive optics to correct optical aberrations of the human eye in real time. High axial resolution and high speed are made possible by the use of Fourier-domain optical coherence tomography. Using this system, we have demonstrated the ability to image microscopic blood vessels and the cone photoreceptor mosaic.

  6. Optical asymmetric image encryption using gyrator wavelet transform (United States)

    Mehra, Isha; Nishchal, Naveen K.


    In this paper, we propose a new optical information processing tool termed as gyrator wavelet transform to secure a fully phase image, based on amplitude- and phase-truncation approach. The gyrator wavelet transform constitutes four basic parameters; gyrator transform order, type and level of mother wavelet, and position of different frequency bands. These parameters are used as encryption keys in addition to the random phase codes to the optical cryptosystem. This tool has also been applied for simultaneous compression and encryption of an image. The system's performance and its sensitivity to the encryption parameters, such as, gyrator transform order, and robustness has also been analyzed. It is expected that this tool will not only update current optical security systems, but may also shed some light on future developments. The computer simulation results demonstrate the abilities of the gyrator wavelet transform as an effective tool, which can be used in various optical information processing applications, including image encryption, and image compression. Also this tool can be applied for securing the color image, multispectral, and three-dimensional images.

  7. Imaging vascular implants with optical coherence tomography (United States)

    Barton, Jennifer K.; Dal Ponte, Donny B.; Williams, Stuart K.; Ford, Bridget K.; Descour, Michael R.


    Vascular stents and grafts have many proven and promising clinical applications, but also a large number of complications. A focus of current research is the development of biocompatible implants. Evaluation of these devices generally requires a large number of animals due to the need for explanation and histological evaluation of the implant at several time intervals. It would be desirable to use instead a high resolution, in situ assessment method. An in vitro study was performed to determine if OCT could image cell proliferation and thrombus formation on vascular stents and grafts. First, images were taken of explanted stents. The implants were locate din peripheral vessels of a porcine model of atherosclerosis. The images clearly show the vessel response to initial damage, the materials of the implant, extent of intimal cell hyper proliferation, and small platelet aggregates. Next, a tissue engineered graft, which had been sodded with smooth muscle cells and incubated in a bioreactor, was evaluated. Cross-section images showed the pores of the polymer material and the layer of smooth muscle cells beginning to invade the graft material. For comparison, in vitro 20 MHz IVUS images of the same grafts were obtained. A catheter was designed for intravascular imaging. The 2.3 mm diameter catheter contains a fiber with GRIN lens and right angle prism, a monorail guidewire, and a novel positioning wire that can be protruded to push the catheter against the vessel wall, potentially eliminating the need for saline flush. Preliminary in vitro results with this catheter are encouraging.

  8. Evaluation of Fingerprint Images Captured by Optical Fingerprint Scanner (United States)

    Takeuchi, Hideyo; Matsumoto, Noriyuki; Kuwayama, Kiyoaki; Umezaki, Taizo

    In this paper, we propose the way to evaluate fingerprint image-quality and how to discriminate remnants from captured images. First, we investigate evaluating fingerprint image-quality. Fingerprint image-quality can be digitized using the "measure" we proposed. We simulate using the dataset consists of 1425 fingerprint images captured from 57 people in Feb, which contains a lot of faded images. In the simulation using all our database, recognition rate is 95.6% while type II error is 0.01%. Recognition rate is improved to 98.1%, with rejecting 3.7% faded images evaluated by our measure from the database. Recognition rate is improved to 99.6%, rejecting 14.2% faded images. And we investigate the way to apply the measure of image-quality to fingerprint verification device with customer’s satisfaction in real world. Next we propose the way to discriminate between remnants and fingerprint images captured from optical scanner by using frequency analysis. We can perfectly prevent the fingerprint verification device from malfunctioning caused by remnant, when strong flashlight or direct sunlight slant in optical scanner in real world.

  9. Optical tissue clearing improves usability of optical coherence tomography (OCT) for high-throughput analysis of the internal structure and 3D morphology of small biological objects such as vertebrate embryos

    DEFF Research Database (Denmark)

    Thrane, Lars; Jørgensen, Thomas Martini; Männer, Jörg


    Developmental biology studies frequently require rapid analysis of the morphology of a large number of embryos (highthroughput analysis). Conventional microscopic analysis is time-consuming and, therefore, is not well suited for highthroughput analysis. OCT facilitates rapid generation of optical...... sections through small biological objects at high resolutions. However, due to light scattering within biological tissues, the quality of OCT images drops significantly with increasing penetration depth of the light beam. We show that optical clearing of fixed embryonic organs with methyl benzoate can...... significantly reduce the light scattering and, thereby, improves the usability of OCT for high-throughput analysis of embryonic morphology....

  10. All-optical scanhead for ultrasound and photoacoustic imaging-Imaging mode switching by dichroic filtering. (United States)

    Hsieh, Bao-Yu; Chen, Sung-Liang; Ling, Tao; Guo, L Jay; Li, Pai-Chi


    Ultrasound (US) and photoacoustic (PA) multimodality imaging has the advantage of combining good acoustic resolution with high optical contrast. The use of an all-optical scanhead for both imaging modalities can simplify integration of the two systems and miniaturize the imaging scanhead. Herein we propose and demonstrate an all-optical US/PA scanhead using a thin plate for optoacoustic generation in US imaging, a polymer microring resonator for acoustic detection, and a dichroic filter to switch between the two imaging modes by changing the laser wavelength. A synthetic-aperture focusing technique is used to improve the resolution and contrast. Phantom images demonstrate the feasibility of this design, and show that axial and lateral resolutions of 125 μm and 2.52°, respectively, are possible.

  11. Camera, handlens, and microscope optical system for imaging and coupled optical spectroscopy (United States)

    Mungas, Greg S. (Inventor); Boynton, John (Inventor); Sepulveda, Cesar A. (Inventor); Nunes de Sepulveda, legal representative, Alicia (Inventor); Gursel, Yekta (Inventor)


    An optical system comprising two lens cells, each lens cell comprising multiple lens elements, to provide imaging over a very wide image distance and within a wide range of magnification by changing the distance between the two lens cells. An embodiment also provides scannable laser spectroscopic measurements within the field-of-view of the instrument.

  12. Characterizing and imaging magnetic nanoparticles by optical magnetometry (United States)

    Weis, A.; Colombo, S.; Dolgovskiy, V.; Grujić, Z. D.; Lebedev, V.; Zhang, J.


    We review our ongoing work on deploying optical (atomic) magnetometry for measuring the magnetic response of magnetic nanoparticle (MNP) samples, yielding MNP size distributions, and other sample parameters like Néel relaxation time τ, saturation magnetisation Ms , anisotropy constant K and magnetic susceptibility χ. We address magnetorelaxation (MRX) signals, in which the decaying magnetisation M(t) following a magnetising pulse is recorded by a single atomic magnetometer or by a novel magnetic source imaging camera (MSIC) allowing spatially resolved MRX studies of distributed MNP samples. We further show that optical magnetometers can be used for a direct measurement of the M(H) and dM/dH(H) dependencies of MNP samples, the latter forming the basis for an optical magnetometer implementation of the MPI (Magnetic Particle Imaging) method. All experiments are in view of developing biomedical imaging modalities.

  13. Synthesis of Disparate Optical Imaging Data for Space Domain Awareness

    CERN Document Server

    Schneider, Michael D


    We present a Bayesian algorithm to combine optical imaging of unresolved objects from distinct epochs and observation platforms for orbit determination and tracking. By propagating the non-Gaussian uncertainties we are able to optimally combine imaging of arbitrary signal-to-noise ratios, allowing the integration of data from low-cost sensors. Our Bayesian approach to image characterization also allows large compression of imaging data without loss of statistical information. With a computationally efficient algorithm to combine multiple observation epochs and multiple telescopes, we show statistically optimal orbit inferences.

  14. All-optical photoacoustic imaging system using fiber ultrasound probe and hollow optical fiber bundle. (United States)

    Miida, Yusuke; Matsuura, Yuji


    An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end.

  15. Biological effects of exposure to magnetic resonance imaging: an overview

    Directory of Open Access Journals (Sweden)

    Formica Domenico


    Full Text Available Abstract The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to allow the integration of the specific literature on the bio-effects produced by magnetic resonance systems with the vast literature concerning the bio-effects produced by electromagnetic fields. This work gives an overview of the findings about the safety concerns of exposure to static magnetic fields, radio-frequency fields, and time varying magnetic field gradients, focusing primarily on the physics of the interactions between these electromagnetic fields and biological matter. The scientific literature is summarized, integrated, and critically analyzed with the help of authoritative reviews by recognized experts, international safety guidelines are also cited.

  16. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

    Directory of Open Access Journals (Sweden)

    Lei Zhu, Ning Guo, Quanzheng Li, Ying Ma, Orit Jacboson, Seulki Lee, Hak Soo Choi, James R. Mansfield, Gang Niu, Xiaoyuan Chen


    Full Text Available Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide.Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data.Results: The dual-labeled probe 64Cu-RGD-C(DOTA-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp derived from dynamic optical imaging (1.762 ± 0.020 is comparable to that from dynamic PET (1.752 ± 0.026.Conclusion: The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  17. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Guy, J.; Mancuso, A.; Beck, R.; Moster, M.L.; Sedwick, L.A.; Quisling, R.G.; Rhoton, A.L. Jr.; Protzko, E.E.; Schiffman, J. (Univ. of Florida, Gainesville (USA))


    Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

  18. Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications. (United States)

    Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W; Dokmeci, Mehmet Remzi; Boyden, Edward S; Khademhosseini, Ali


    To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such "hybrid microscopy" methods--combining physical and optical magnifications--can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes ("mini-microscopes"), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics--a process we refer to as Expansion Mini-Microscopy (ExMM)--is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

  19. Fast Calcium Imaging with Optical Sectioning via HiLo Microscopy. (United States)

    Lauterbach, Marcel A; Ronzitti, Emiliano; Sternberg, Jenna R; Wyart, Claire; Emiliani, Valentina


    Imaging intracellular calcium concentration via reporters that change their fluorescence properties upon binding of calcium, referred to as calcium imaging, has revolutionized our way to probe neuronal activity non-invasively. To reach neurons densely located deep in the tissue, optical sectioning at high rate of acquisition is necessary but difficult to achieve in a cost effective manner. Here we implement an accessible solution relying on HiLo microscopy to provide robust optical sectioning with a high frame rate in vivo. We show that large calcium signals can be recorded from dense neuronal populations at high acquisition rates. We quantify the optical sectioning capabilities and demonstrate the benefits of HiLo microscopy compared to wide-field microscopy for calcium imaging and 3D reconstruction. We apply HiLo microscopy to functional calcium imaging at 100 frames per second deep in biological tissues. This approach enables us to discriminate neuronal activity of motor neurons from different depths in the spinal cord of zebrafish embryos. We observe distinct time courses of calcium signals in somata and axons. We show that our method enables to remove large fluctuations of the background fluorescence. All together our setup can be implemented to provide efficient optical sectioning in vivo at low cost on a wide range of existing microscopes.

  20. Teaching Optics to Biology Students Through Constructing a Light Microscope (United States)

    Ross, Jennifer


    The microscope is familiar to many disciplines, including physics, materials science, chemistry, and the life sciences. It demonstrates fundamental aspects of ray and wave optics, making it an ideal system to help educate students in the basic concepts of optics and in measurement principles and techniques. We present an experimental system developed to teach students the basics of ray and wave optics. The students design, build, and test a light microscope made from optics components. We describe the equipment and the basic measurements that students can perform to develop experimental techniques to understand optics principles. Students measure the magnification and test the resolution of the microscope. The system is open and versatile to allow advanced projects such as epi-fluorescence, total internal reflection fluorescence, and optical trapping. We have used this equipment in an optics course, an advanced laboratory course, and graduate-level training modules.

  1. Computational optical biomedical spectroscopy and imaging

    CERN Document Server

    Musa, Sarhan M


    Applications of Vibrational Spectroscopic Imaging in Personal Care Studies; Guojin Zhang, Roger L. McMullen, Richard Mendelsohn, and Osama M. MusaFluorescence Bioimaging with Applications to Chemistry; Ufana Riaz and S.M. AshrafNew Trends in Immunohistochemical, Genome, and Metabolomics Imaging; G. Livanos, Aditi Deshpande, C. Narayan, Ying Na, T. Quang, T. Farrahi, R. Koglin, Suman Shrestha, M. Zervakis, and George C. GiakosDeveloping a Comprehensive Taxonomy for Human Cell Types; Richard Conroy and Vinay PaiFunctional Near-Infrared S

  2. FY05 LDRD Final Report, A Revolution in Biological Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, H N; Bajt, S; Balhorn, R; Barty, A; Barsky, D; Bogan, M; Chung, S; Frank, M; Hau-Riege, S; Ishii, H; London, R; Marchesini, S; Noy, A; Segelke, B; Szoke, A; Szoke, H; Trebes, J; Wootton, A; Hajdu, J; Bergh, M; Caleman, C; Huldt, G; Lejon, S; der Spoel, D v; Howells, M; He, H; Spence, J; Nugent, K; Ingerman, E


    X-ray free-electron lasers (XFELs) are currently under development and will provide a peak brightness more than 10 orders of magnitude higher than modern synchrotrons. The goal of this project was to perform the fundamental research to evaluate the possibility of harnessing these unique x-ray sources to image single biological particles and molecules at atomic resolution. Using a combination of computational modeling and experimental verification where possible, they showed that it should indeed be possible to record coherent scattering patterns from single molecules with pulses that are shorter than the timescales for the degradation of the structure due to the interaction with those pulses. They used these models to determine the effectiveness of strategies to allow imaging using longer XFEL pulses and to design validation experiments to be carried out at interim ultrafast sources. They also developed and demonstrated methods to recover three-dimensional (3D) images from coherent diffraction patterns, similar to those expected from XFELs. The images of micron-sized test objects are the highest-resolution 3D images of any noncrystalline material ever formed with x-rays. The project resulted in 14 publications in peer-reviewed journals and four records of invention.

  3. Fast optical measurements and imaging of flow mixing

    DEFF Research Database (Denmark)

    Clausen, Sønnik; Fateev, Alexander; Nielsen, Karsten Lindorff;

    in combustion enhancement can be also obtained. The infrared camera was also used together with special endoscope optics for fast thermal imaging of a coal-straw flame in an industrial boiler. Obtained time-resolved infrared images provided useful information for the diagnostics of the flame and fuel......Project is focused on fast time-resolved infrared measurements of gas temperature and fast IR-imagining of flames in various combustion environments. The infrared spectrometer system was developed in the project for fast infrared spectral measurements on industrial scale using IR-fibre- optics...

  4. New approach to imaging spectroscopy using diffractive optics (United States)

    Hinnrichs, Michele; Massie, Mark A.


    Over the past several years, Pacific Advanced Technology (PAT) has developed several hyperspectral imagers using diffractive optics as the dispersive media. This new approach has been patented and demonstrated in numerous field tests. PAT has developed hyperspectral cameras in the visible, mid-wave IR and is currently under contrast to the Air Force to develop a dual band hyperspectral lens for simultaneous spectral imaging in both the mid-wave and long- wave IR. The development of these cameras over the years have been sponsored by internal research and development, contracts from the Air Force Phillips Lab., Air Force Wright Labs Armament Division, BMDO and by the Office of Naval Research. Numerous papers have been presented in the past describing the performance of these various hyperspectral cameras. The purpose of this paper is to describe the theory behind the image multi-spectral sensing (IMSS) used in these hyperspectral cameras. IMSS utilizes a very simple optical design that enables a robust and low cost hyper-spectral imaging instrument. The IMSS is a dispersive spectrometer using a single diffractive optical element for both imaging and dispersion. The lens is tuned for a single wavelength giving maximum diffraction efficiency at that wavelength and high efficiency throughout the spectral band-pass of the camera. The diffractive optics disperse the light along the optical axis as opposed to perpendicular to the axis in conventional dispersive spectrometers. A detector array is used as the sensing medium and the spectral images are rad out electronically. POst processing is used to reduce spectral cross talk and to spatially sharpen the spectral images.

  5. Optical fiber based imaging of bioengineered tissue construct (United States)

    Sapoznik, Etai; Niu, Guoguang; Lu, Peng; Zhou, Yu; Xu, Yong; Soker, Shay


    Imaging cells and tissues through opaque and turbid media is challenging and presents a major barrier for monitoring maturation and remodeling of bioengineered tissues. The fiber optics based imaging system described here offers a new approach for fluorescent cell imaging. A micro imaging channel is embedded in a Polycaprolactone (PCL) electrospun scaffold designed for cell seeding, which allows us to use an optical fiber to locally deliver excitation laser close to the fluorescent cells. The emission is detected by an Electron Multiplying Charge Coupled Device (EMCCD) detector and image reconstruction of multiple excitation points is achieved with a working distance of several centimeters. The objective of this study is to assess the effects of system parameters on image reconstruction outcomes. Initial studies using fluorescent beads indicated that scaffold thickness had a small effect on image quality, whereas scaffold composition (collagen content), fluorophore spectra, and the reconstruction window size had a large effect. The results also suggest that a far-red fluorescent emission is preferential when using collagenous scaffolds with a thickness of up to 500 μm. Using these optimized parameters, we were able to image fluorescently labeled cells on a scaffold with a resolution of 15-20 μm, and have also measured muscle progenitor cell differentiation and scaffold surface coverage with endothelial cells. In the future, this imaging platform can be applied to other bioengineered tissues for non-invasive monitoring both in vitro and in vivo.

  6. The diffractive achromat full spectrum computational imaging with diffractive optics

    KAUST Repository

    Peng, Yifan


    Diffractive optical elements (DOEs) have recently drawn great attention in computational imaging because they can drastically reduce the size and weight of imaging devices compared to their refractive counterparts. However, the inherent strong dispersion is a tremendous obstacle that limits the use of DOEs in full spectrum imaging, causing unacceptable loss of color fidelity in the images. In particular, metamerism introduces a data dependency in the image blur, which has been neglected in computational imaging methods so far. We introduce both a diffractive achromat based on computational optimization, as well as a corresponding algorithm for correction of residual aberrations. Using this approach, we demonstrate high fidelity color diffractive-only imaging over the full visible spectrum. In the optical design, the height profile of a diffractive lens is optimized to balance the focusing contributions of different wavelengths for a specific focal length. The spectral point spread functions (PSFs) become nearly identical to each other, creating approximately spectrally invariant blur kernels. This property guarantees good color preservation in the captured image and facilitates the correction of residual aberrations in our fast two-step deconvolution without additional color priors. We demonstrate our design of diffractive achromat on a 0.5mm ultrathin substrate by photolithography techniques. Experimental results show that our achromatic diffractive lens produces high color fidelity and better image quality in the full visible spectrum. © 2016 ACM.

  7. Change detection in very high resolution multisensor optical images (United States)

    Solano Correa, Yady T.; Bovolo, Francesca; Bruzzone, Lorenzo


    This work aims at developing an approach to the detection of changes in multisensor multitemporal VHR optical images. The main steps of the proposed method are: i) multisensor data homogenization; and ii) change detection in multisensor multitemporal VHR optical images. The proposed approach takes advantage of: the conversion to physical quantities suggested by Pacifici et. al.1 , the framework for the design of systems for change detection in VHR images presented by Bruzzone and Bovolo2 and the framework for unsupervised change detection presented by Bovolo and Bruzzone3. Multisensor data homogenization is achieved during pre-processing by taking into account differences in both radiometric and geometric dimensions. Whereas change detection was approached by extracting proper features from multisensor images such that they result to be comparable (at a given level of abstraction) even if extracted from images acquired by different sensors. In order to illustrate the results, a data set made up of a QuickBird and a WorldView-2 images - acquired in 2006 and 2010 respectively - over an area located in the Trentino region of Italy were used. However, the proposed approach is thought to be exportable to multitemporal images coming from passive sensors other than the two mentioned above. The experimental results obtained on the QuickBird and WorlView-2 image pair are accurate. Thus opening to further experiments on multitemporal images acquired by other sensors.

  8. High-speed optical frequency-domain imaging


    Yun, S. H.; Tearney, G. J.; Boer; Iftimia, N. V.; Bouma, B. E.


    We demonstrate high-speed, high-sensitivity, high-resolution optical imaging based on optical frequency-domain interferometry using a rapidly-tuned wavelength-swept laser. We derive and show experimentally that frequency-domain ranging provides a superior signal-to-noise ratio compared with conventional time-domain ranging as used in optical coherence tomography. A high sensitivity of −110 dB was obtained with a 6 mW source at an axial resolution of 13.5 µm and an A-line rate of 15.7 kHz, rep...

  9. High-speed image matching with coaxial holographic optical correlator (United States)

    Ikeda, Kanami; Watanabe, Eriko


    A computation speed of more than 100 Gbps is experimentally demonstrated using our developed ultrahigh-speed optical correlator. To verify this high computation speed practically, the computation speeds of our optical correlator and conventional digital image matching are quantitatively compared. We use a population count function that achieves the fastest calculation speed when calculating binary matching by a central processing unit (CPU). The calculation speed of the optical correlator is dramatically faster than that using a CPU (2.40 GHz × 4) and 16 GB of random access memory, especially when the calculation data are large-scale.

  10. The Subaru Deep Field: The Optical Imaging Data

    CERN Document Server

    Kashikawa, N; Yasuda, N; Ajiki, M; Akiyama, M; Ando, H; Aoki, K; Doi, M; Fujita, S S; Furusawa, H; Hayashino, T; Iwamuro, F; Iye, M; Karoji, H; Kobayashi, N; Kodaira, K; Kodama, T; Komiyama, Yu; Matsuda, Y; Miyazaki, S; Mizumoto, Y; Morokuma, T; Motohara, K; Murayama, T; Nagao, T; Nariai, K; Ohta, K; Okamura, S; Ouchi, M; Sasaki, T; Sato, Y; Sekiguchi, K; Shioya, Y; Tamura, H; Taniguchi, Y; Umemura, M; Yamada, T; Yoshida, M


    The Subaru Deep Field (SDF) project is a program of Subaru Observatory to carry out a deep galaxy survey over a blank field as large as 34'x27'. The program consists of very deep multi-band optical imaging, near infrared imaging for smaller portions of the field and follow-up optical spectroscopy. Major scientific goals of the project are to construct large samples of Lyman-break galaxies at z~4-5 and Lyman alpha emitters at z~5.7 and 6.6, and to make detailed studies these very high-redshift galaxy populations. In this paper, we describe the optical imaging observations and data reduction, presenting mosaicked images and object catalogs in seven bandpasses.The optical imaging was made through five broad-band filters, B, V, R, i', z', and two narrow-band filters, NB816 (lambda_c=8150A) and NB921 (lambda_c=9196A) with almost 10 hours long integrations for each band. The limiting magnitudes measured at 3-sigma on a 2" aperture are B=28.45, V=27.74, R=27.80, i'=27.43, z'=26.62, NB816=26.63, and NB921=26.54 in th...

  11. Handheld hyperspectral imager for standoff detection of chemical and biological aerosols (United States)

    Hinnrichs, Michele; Jensen, James O.; McAnally, Gerard


    Pacific Advanced Technology has developed a small hand held imaging spectrometer, Sherlock, for gas leak and aerosol detection and imaging. The system is based on a patented technique, (IMSS Image Multi-spectral Sensing), that uses diffractive optics and image processing algorithms to detect spectral information about objects in the scene of the camera. This cameras technology has been tested at Dugway Proving Ground and Dstl Porton Down facilities looking at Chemical and Biological agent simulants. In addition to Chemical and Biological detection, the camera has been used for environmental monitoring of green house gases and is currently undergoing extensive laboratory and field testing by the Gas Technology Institute, British Petroleum and Shell Oil for applications for gas leak detection and repair. In this paper we will present some of the results from the data collection at the TRE test at Dugway Proving Ground during the summer of 2002 and laboratory testing at the Dstl facility at Porton Down in the UK in the fall of 2002.

  12. Broadband Incoherent Imaging Using Multiple Aperture Optics (United States)


    objects was by Galileo Galilei in the fall of 1609 (3:30). From that day on, the drive has been to improve upon the quality of the received image...increased diameter. (11:763) A second major drawback is the sheer weight of the mirror. Even Galileo realized that there is a limit to the size of a mirror

  13. Table-top diffuse optical imaging

    NARCIS (Netherlands)

    Sturgeon, K.A.; Bakker, L.P.


    This report describes the work done during a six months internshipat Philips Research for a Masters in Electronic and Electrical Engineering. An existing table-top tomography system for measuring lightin phantom breasts was restored. Updated software control and image reconstruction software was cr

  14. Optical imaging of individual biomolecules in densely packed clusters (United States)

    Dai, Mingjie; Jungmann, Ralf; Yin, Peng


    Recent advances in fluorescence super-resolution microscopy have allowed subcellular features and synthetic nanostructures down to 10-20 nm in size to be imaged. However, the direct optical observation of individual molecular targets (∼5 nm) in a densely packed biomolecular cluster remains a challenge. Here, we show that such discrete molecular imaging is possible using DNA-PAINT (points accumulation for imaging in nanoscale topography)—a super-resolution fluorescence microscopy technique that exploits programmable transient oligonucleotide hybridization—on synthetic DNA nanostructures. We examined the effects of a high photon count, high blinking statistics and an appropriate blinking duty cycle on imaging quality, and developed a software-based drift correction method that achieves optical nanodisplay with 5 × 5 nm pixel size and three distinct colours with <1 nm cross-channel registration accuracy.

  15. Automated Localization of Optic Disc in Retinal Images

    Directory of Open Access Journals (Sweden)

    Deepali A.Godse


    Full Text Available An efficient detection of optic disc (OD in colour retinal images is a significant task in an automated retinal image analysis system. Most of the algorithms developed for OD detection are especially applicable to normal and healthy retinal images. It is a challenging task to detect OD in all types of retinal images, that is, normal, healthy images as well as abnormal, that is, images affected due to disease. This paper presents an automated system to locate an OD and its centre in all types of retinal images. The ensemble of steps based on different criteria produces more accurate results. The proposed algorithm gives excellent results and avoids false OD detection. The technique is developed and tested on standard databases provided for researchers on internet, Diaretdb0 (130 images, Diaretdb1 (89 images, Drive (40 images and local database (194 images. The local database images are collected from ophthalmic clinics. It is able to locate OD and its centre in 98.45% of all tested cases. The results achieved by different algorithms can be compared when algorithms are applied on same standard databases. This comparison is also discussed in this paper which shows that the proposed algorithm is more efficient.

  16. Bioluminescence : the potential of a non-invasive bio-optical imaging technique and improvement of animal research

    NARCIS (Netherlands)

    Hesselink, J. W.; van Dam, G. M.


    Bioluminescence is an optical imaging technique that exploits the emission of photons at specific wavelengths based on energy-dependent reactions catalysed by luciferases. The technique makes it possible to monitor measure, and track biological processes in living animals. A short review is presente

  17. Optical coherence tomography-based micro-particle image velocimetry. (United States)

    Mujat, Mircea; Ferguson, R Daniel; Iftimia, Nicusor; Hammer, Daniel X; Nedyalkov, Ivaylo; Wosnik, Martin; Legner, Hartmut


    We present a new application of optical coherence tomography (OCT), widely used in biomedical imaging, to flow analysis in near-wall hydrodynamics for marine research. This unique capability, called OCT micro-particle image velocimetry, provides a high-resolution view of microscopic flow phenomena and measurement of flow statistics within the first millimeter of a boundary layer. The technique is demonstrated in a small flow cuvette and in a water tunnel.

  18. Closed-loop optical stabilization and digital image registration in adaptive optics scanning light ophthalmoscopy. (United States)

    Yang, Qiang; Zhang, Jie; Nozato, Koji; Saito, Kenichi; Williams, David R; Roorda, Austin; Rossi, Ethan A


    Eye motion is a major impediment to the efficient acquisition of high resolution retinal images with the adaptive optics (AO) scanning light ophthalmoscope (AOSLO). Here we demonstrate a solution to this problem by implementing both optical stabilization and digital image registration in an AOSLO. We replaced the slow scanning mirror with a two-axis tip/tilt mirror for the dual functions of slow scanning and optical stabilization. Closed-loop optical stabilization reduced the amplitude of eye-movement related-image motion by a factor of 10-15. The residual RMS error after optical stabilization alone was on the order of the size of foveal cones: ~1.66-2.56 μm or ~0.34-0.53 arcmin with typical fixational eye motion for normal observers. The full implementation, with real-time digital image registration, corrected the residual eye motion after optical stabilization with an accuracy of ~0.20-0.25 μm or ~0.04-0.05 arcmin RMS, which to our knowledge is more accurate than any method previously reported.

  19. Optical coherence tomography imaging of the basal ganglia: feasibility and brief review

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, W. O. Contreras; Ângelos, J. S. [Divisão de Neurocirurgia Funcional, Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Martinez, R. C. R. [Laboratório de Neuromodulação e Dor Experimental, Hospital Sírio-Libanes, São Paulo, SP (Brazil); Takimura, C. K. [Instituto do Coração, Universidade de São Paulo, São Paulo, SP (Brazil); Teixeira, M. J. [Divisão de Neurocirurgia Funcional, Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Lemos, P. A. Neto [Instituto do Coração, Universidade de São Paulo, São Paulo, SP (Brazil); Fonoff, E. T., E-mail: [Divisão de Neurocirurgia Funcional, Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)


    Optical coherence tomography (OCT) is a promising medical imaging technique that uses light to capture real-time cross-sectional images from biological tissues in micrometer resolution. Commercially available optical coherence tomography systems are employed in diverse applications, including art conservation and diagnostic medicine, notably in cardiology and ophthalmology. Application of this technology in the brain may enable distinction between white matter and gray matter, and obtainment of detailed images from within the encephalon. We present, herein, the in vivo implementation of OCT imaging in the rat brain striatum. For this, two male 60-day-old rats (Rattus norvegicus, Albinus variation, Wistar) were stereotactically implanted with guide cannulas into the striatum to guide a 2.7-French diameter high-definition OCT imaging catheter (Dragonfly™, St. Jude Medical, USA). Obtained images were compared with corresponding histologically stained sections to collect imaging samples. A brief analysis of OCT technology and its current applications is also reported, as well as intra-cerebral OCT feasibility on brain mapping during neurosurgical procedures.

  20. Innovations of wide-field optical-sectioning fluorescence microscopy: toward high-speed volumetric bio-imaging with simplicity (United States)

    Yu, Jiun-Yann

    Optical microscopy has become an indispensable tool for biological researches since its invention, mostly owing to its sub-cellular spatial resolutions, non-invasiveness, instrumental simplicity, and the intuitive observations it provides. Nonetheless, obtaining reliable, quantitative spatial information from conventional wide-field optical microscopy is not always intuitive as it appears to be. This is because in the acquired images of optical microscopy the information about out-of-focus regions is spatially blurred and mixed with in-focus information. In other words, conventional wide-field optical microscopy transforms the three-dimensional spatial information, or volumetric information about the objects into a two-dimensional form in each acquired image, and therefore distorts the spatial information about the object. Several fluorescence holography-based methods have demonstrated the ability to obtain three-dimensional information about the objects, but these methods generally rely on decomposing stereoscopic visualizations to extract volumetric information and are unable to resolve complex 3-dimensional structures such as a multi-layer sphere. The concept of optical-sectioning techniques, on the other hand, is to detect only two-dimensional information about an object at each acquisition. Specifically, each image obtained by optical-sectioning techniques contains mainly the information about an optically thin layer inside the object, as if only a thin histological section is being observed at a time. Using such a methodology, obtaining undistorted volumetric information about the object simply requires taking images of the object at sequential depths. Among existing methods of obtaining volumetric information, the practicability of optical sectioning has made it the most commonly used and most powerful one in biological science. However, when applied to imaging living biological systems, conventional single-point-scanning optical-sectioning techniques often

  1. 4F-based optical phase imaging system

    DEFF Research Database (Denmark)


    The invention relates to 4F-based optical phase imaging system and in particular to reconstructing quantitative phase information of an object when using such systems. The invention applies a two-dimensional, complex spatial light modulator (SLM) to impress a complex spatial synthesized modulation...... in addition to the complex spatial modulation impressed by the object. This SLM is arranged so that the synthesized modulation is superimposed with the object modulation and is thus placed at an input plane to the phase imaging system. By evaluating output images from the phase imaging system, the synthesized...... modulation is selected to optimize parameters in the output image which improves the reconstruction of qualitative and quantitative object phase information from the resulting output images....

  2. The optics of microscope image formation. (United States)

    Wolf, David E


    Although geometric optics gives a good understanding of how the microscope works, it fails in one critical area, which is explaining the origin of microscope resolution. To accomplish this, one must consider the microscope from the viewpoint of physical optics. This chapter describes the theory of the microscope-relating resolution to the highest spatial frequency that a microscope can collect. The chapter illustrates how Huygens' principle or construction can be used to explain the propagation of a plane wave. It is shown that this limit increases with increasing numerical aperture (NA). As a corollary to this, resolution increases with decreasing wavelength because of how NA depends on wavelength. The resolution is higher for blue light than red light. Resolution is dependent on contrast, and the higher the contrast, the higher the resolution. This last point relates to issues of signal-to-noise and dynamic range. The use of video and new digital cameras has necessitated redefining classical limits such as those of Rayleigh's criterion.

  3. Optical Picosecond MCPI-Based Imagers

    Energy Technology Data Exchange (ETDEWEB)

    Buckles, R. A.; guyton, R. L.; Ross, P. W.


    We report on the design, construction, and initial test results of a custom MCPI design which incorporates a wideband strip transmission line drive structure. A special 16:1 series transmission-line-transformer (STLT) is utilized to distribute the drive signal from a 50-ohm, 1.85 mm coaxial vacuum feedthrough to a 3-ohm strip across the MCP. Transformer circuit material is a flexible Teflon/Kapton laminate for minimal loss and dispersion. A novel vialess multilayer structure composed of embedded, symmetrical strips, preserves ideal impulse response. Impedance matched interfaces and transitions are designed with method of moments, empirical codes, and finite element analysis. Millimeter-wave time-domain reflectometer and vector network analyzer measurements are presented, with comparison to time-domain and swept frequency 3D finite element simulation. Gain compression is expected to produce a 20 ps optical impulse response, dominated by the leaded MCP glass dielectric dispersion. Follow-on work will complete the optical impulse response tests, and extrapolation to more expensive silicon MCP and 1-mm feedthroughs promises an impulse response of 5 ps.

  4. Functional Doppler optical coherence tomography for cortical blood flow imaging (United States)

    Yu, Lingfeng; Liu, Gangjun; Nguyen, Elaine; Choi, Bernard; Chen, Zhongping


    Optical methods have been widely used in basic neuroscience research to study the cerebral blood flow dynamics in order to overcome the low spatial resolution associated with magnetic resonance imaging and positron emission tomography. Although laser Doppler imaging and laser speckle imaging can map out en face cortical hemodynamics and columns, depth resolution is not available. Two-photon microscopy has been used for mapping cortical activity. However, flow measurement requires fluorescent dye injection, which can be problematic. The noninvasive and high resolution tomographic capabilities of optical coherence tomography make it a promising technique for mapping depth resolved cortical blood flow. Here, we present a functional Doppler optical coherence tomography (OCT) imaging modality for quantitative evaluation of cortical blood flow in a mouse model. Fast, repeated, Doppler OCT scans across a vessel of interest were performed to record flow dynamic information with a high temporal resolution of the cardiac cycles. Spectral Doppler analysis of continuous Doppler images demonstrates how the velocity components and longitudinally projected flow-volume-rate change over time, thereby providing complementary temporal flow information to the spatially distributed flow information of Doppler OCT. The proposed functional Doppler OCT imaging modality can be used to diagnose vessel stenosis/blockage or monitor blood flow changes due to pharmacological agents/neuronal activities. Non-invasive in-vivo mice experiments were performed to verify the capabilities of function Doppler OCT.

  5. Adapting smartphones for low-cost optical medical imaging (United States)

    Pratavieira, Sebastião.; Vollet-Filho, José D.; Carbinatto, Fernanda M.; Blanco, Kate; Inada, Natalia M.; Bagnato, Vanderlei S.; Kurachi, Cristina


    Optical images have been used in several medical situations to improve diagnosis of lesions or to monitor treatments. However, most systems employ expensive scientific (CCD or CMOS) cameras and need computers to display and save the images, usually resulting in a high final cost for the system. Additionally, this sort of apparatus operation usually becomes more complex, requiring more and more specialized technical knowledge from the operator. Currently, the number of people using smartphone-like devices with built-in high quality cameras is increasing, which might allow using such devices as an efficient, lower cost, portable imaging system for medical applications. Thus, we aim to develop methods of adaptation of those devices to optical medical imaging techniques, such as fluorescence. Particularly, smartphones covers were adapted to connect a smartphone-like device to widefield fluorescence imaging systems. These systems were used to detect lesions in different tissues, such as cervix and mouth/throat mucosa, and to monitor ALA-induced protoporphyrin-IX formation for photodynamic treatment of Cervical Intraepithelial Neoplasia. This approach may contribute significantly to low-cost, portable and simple clinical optical imaging collection.

  6. Establishing Information Security Systems via Optical Imaging (United States)


    Laser Object Computer Fig. 5. A schematic setup for the proposed method using holography: BSC, Beam splitter cube; CCD, Charge-coupled device. The...SLM Object~~~, ........ . . . . . . . . . . . . . . . . . Laser CCD DJ Fig. 9. A schematic for computational ghost imaging: BD, bucket detector...polarization. (c) Since the sophisticated optoelectronic devices and systems should be analyzed before the retrieval, any hostile hacker will need to

  7. Computer-aided interpretation approach for optical tomographic images (United States)

    Klose, Christian D.; Klose, Alexander D.; Netz, Uwe J.; Scheel, Alexander K.; Beuthan, Jürgen; Hielscher, Andreas H.


    A computer-aided interpretation approach is proposed to detect rheumatic arthritis (RA) in human finger joints using optical tomographic images. The image interpretation method employs a classification algorithm that makes use of a so-called self-organizing mapping scheme to classify fingers as either affected or unaffected by RA. Unlike in previous studies, this allows for combining multiple image features, such as minimum and maximum values of the absorption coefficient for identifying affected and not affected joints. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index, and mutual information. Different methods (i.e., clinical diagnostics, ultrasound imaging, magnet resonance imaging, and inspection of optical tomographic images), were used to produce ground truth benchmarks to determine the performance of image interpretations. Using data from 100 finger joints, findings suggest that some parameter combinations lead to higher sensitivities, while others to higher specificities when compared to single parameter classifications employed in previous studies. Maximum performances are reached when combining the minimum/maximum ratio of the absorption coefficient and image variance. In this case, sensitivities and specificities over 0.9 can be achieved. These values are much higher than values obtained when only single parameter classifications were used, where sensitivities and specificities remained well below 0.8.

  8. Optical-resolution photoacoustic imaging through thick tissue with a thin capillary as a dual optical-in acoustic-out waveguide

    CERN Document Server

    Simandoux, Olivier; Gateau, Jerome; Huignard, Jean-Pierre; Moser, Christophe; Psaltis, Demetri; Bossy, Emmanuel


    We demonstrate the ability to guide high-frequency photoacoustic waves through thick tissue with a water-filled silica-capillary (150 \\mu m inner diameter and 30 mm long). An optical-resolution photoacoustic image of a 30 \\mu m diameter absorbing nylon thread was obtained by guiding the acoustic waves in the capillary through a 3 cm thick fat layer. The transmission loss through the capillary was about -20 dB, much lower than the -120 dB acoustic attenuation through the fat layer. The overwhelming acoustic attenuation of high-frequency acoustic waves by biological tissue can therefore be avoided by the use of a small footprint capillary acoustic waveguide for remote detection. We finally demonstrate that the capillary can be used as a dual optical-in acoustic-out waveguide, paving the way for the development of minimally invasive optical-resolution photoacoustic endoscopes free of any acoustic or optical elements at their imaging tip.

  9. Multi-scale volumetric cell and tissue imaging based on optical projection tomography (Conference Presentation) (United States)

    Ban, Sungbea; Cho, Nam Hyun; Ryu, Yongjae; Jung, Sunwoo; Vavilin, Andrey; Min, Eunjung; Jung, Woonggyu


    Optical projection tomography is a new optical imaging method for visualizing small biological specimens in three dimension. The most important advantage of OPT is to fill the gap between MRI and confocal microscope for the specimen having the range of 1-10 mm. Thus, it has been mainly used for whole-mount small animals and developmental study since this imaging modality was developed. The ability of OPT delivering anatomical and functional information of relatively large tissue in 3D has made it a promising platform in biomedical research. Recently, the potential of OPT spans its coverage to cellular scale. Even though there are increasing demand to obtain better understanding of cellular dynamics, only few studies to visualize cellular structure, shape, size and functional morphology over tissue has been investigated in existing OPT system due to its limited field of view. In this study, we develop a novel optical imaging system for 3D cellular imaging with OPT integrated with dynamic focusing technique. Our tomographic setup has great potential to be used for identifying cell characteristic in tissue because it can provide selective contrast on dynamic focal plane allowing for fluorescence as well as absorption. While the dominant contrast of optical imaging technique is to use the fluorescence for detecting certain target only, the newly developed OPT system will offer considerable advantages over currently available method when imaging cellar molecular dynamics by permitting contrast variation. By achieving multi-contrast, it is expected for this new imaging system to play an important role in delivering better cytological information to pathologist.

  10. SOFI Simulation Tool: A Software Package for Simulating and Testing Super-Resolution Optical Fluctuation Imaging. (United States)

    Girsault, Arik; Lukes, Tomas; Sharipov, Azat; Geissbuehler, Stefan; Leutenegger, Marcel; Vandenberg, Wim; Dedecker, Peter; Hofkens, Johan; Lasser, Theo


    Super-resolution optical fluctuation imaging (SOFI) allows one to perform sub-diffraction fluorescence microscopy of living cells. By analyzing the acquired image sequence with an advanced correlation method, i.e. a high-order cross-cumulant analysis, super-resolution in all three spatial dimensions can be achieved. Here we introduce a software tool for a simple qualitative comparison of SOFI images under simulated conditions considering parameters of the microscope setup and essential properties of the biological sample. This tool incorporates SOFI and STORM algorithms, displays and describes the SOFI image processing steps in a tutorial-like fashion. Fast testing of various parameters simplifies the parameter optimization prior to experimental work. The performance of the simulation tool is demonstrated by comparing simulated results with experimentally acquired data.

  11. Glaucoma severity affects diffusion tensor imaging (DTI) parameters of the optic nerve and optic radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sidek, S. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Medical Imaging Unit, Faculty of Medicine, Universiti Teknologi MARA, Selangor (Malaysia); Ramli, N. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Rahmat, K., E-mail: [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia); Ramli, N.M.; Abdulrahman, F. [Department of Ophthalmology, Faculty of Medicine, University Malaya, Kuala Lumpur (Malaysia); Tan, L.K. [Department of Biomedical Imaging, University Malaya, Research Imaging Centre, Faculty of Medicine, University Malaya (Malaysia)


    Objectives: To evaluate whether MR diffusion tensor imaging (DTI) of the optic nerve and optic radiation in glaucoma patients provides parameters to discriminate between mild and severe glaucoma and to determine whether DTI derived indices correlate with retinal nerve fibre layer (RNFL) thickness. Methods: 3-Tesla DTI was performed on 90 subjects (30 normal, 30 mild glaucoma and 30 severe glaucoma subjects) and the FA and MD of the optic nerve and optic radiation were measured. The categorisation into mild and severe glaucoma was done using the Hodapp–Parrish–Anderson (HPA) classification. RNFL thickness was also assessed on all subjects using OCT. Receiver operating characteristic (ROC) analysis and Spearman's correlation coefficient was carried out. Results: FA and MD values in the optic nerve and optic radiation decreased and increased respectively as the disease progressed. FA at the optic nerve had the highest sensitivity (87%) and specificity (80%). FA values displayed the strongest correlation with RNFL thickness in the optic nerve (r = 0.684, p ≤ 0.001) while MD at the optic radiation showed the weakest correlation with RNFL thickness (r = −0.360, p ≤ 0.001). Conclusions: The high sensitivity and specificity of DTI-derived FA values in the optic nerve and the strong correlation between DTI-FA and RNFL thickness suggest that these parameters could serve as indicators of disease severity.

  12. Optical synchrotron radiation beam imaging with a digital mask

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [Univ. of Maryland, College Park, MD (United States); Fiorito, Ralph [Univ. of Maryland, College Park, MD (United States); Corbett, Jeff [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shkvarunets, Anatoly [Univ. of Maryland, College Park, MD (United States); Tian, Kai [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fisher, Alan [SLAC National Accelerator Lab., Menlo Park, CA (United States); Douglas, D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wilson, F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mok, W. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Mitsuhashi, T. [KEK, Tsukuba (Japan)


    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500mA circulating in the storage ring (equivalently 392nC). Each injection pulse contains only 40-80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during User operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by re-imaging visible synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera makes it is possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  13. Magnetic resonance imaging in optic nerve lesions with multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Shigeyuki; Hirayama, Keizo; Kakisu, Yonetsugu; Adachi, Emiko (Chiba Univ. (Japan). School of Medicine)


    Magnetic resonance imaging (MRI) of the optic nerve was performed in 10 patients with multiple sclerosis (MS) using short inversion time inversion recovery (STIR) pulse sequences, and the results were compared with the visual evoked potentials (VEP). The 10 patients had optic neuritis in the chronic or remitting phase together with additional symptoms or signs allowing a diagnosis of clinically definite or probable MS. Sixteen optic nerves were clinically affected and 4 were unaffected. MRI was performed using a 0.5 tesla supeconducting unit, and multiple continuous 5 mm coronal and axial STIR images were obtained. A lesion was judged to be present if a focal or diffuse area of increased signal intensity was detectd in the optic nerve. In VEP, a delay in peak latency or no P 100 component was judged to be abnormal. With regard to the clinically affected optic nerves, MRI revealed a region of increased signal intensity in 14/16 (88%) and the VEP was abnormal in 16/16 (100%). In the clinically unaffected optic nerves, MRI revealed an increased signal intensity in 2/4 (50%). One of these nerves had an abnormal VEP and the other had a VEP latency at the upper limit of normal. The VEP was abnormal in 1/4 (25%). In the clinically affected optic nerves, the degree of loss of visual acuity was not associated with the longitudinal extent of the lesions shown by MRI. The mean length was 17.5 mm in optic nerves with a slight disturbance of visual acuity and 15.0 mm in nerves with severe visual loss. MRI using STIR pulse sequences was found to be almost as sensitive as VEP in detecting both clinically affected and unaffected optic nerve lesions in patients with MS, and was useful in visualizing the location or size of the lesions. (author).

  14. Endocular ophthalmoscope: miniaturization and optical imaging quality (United States)

    Rol, Pascal O.; Beck, Dominik; Niederer, Peter F.


    Endoscopy is a novel method of observation in ocular surgery. It allows a direct viewing of certain internal structures of the eye which can not be seen through conventional slit lamp/microscope arrangements like the back side of the iris, the posterior chamber or the fixation area of an IOL. In addition such an instrument is useful in exploratory orbital surgery because it allows for examination of the scleral wall, the 6 motor muscles and the optic nerve sheet with minimal trauma to the eye. An endoscopic system can therefore be helpful to check regions which can not be reached easily during surgery, such as the ciliary body or the pars plana. When a transparent structure of the eye becomes turbid, e.g., a hazy cornea, observation is impaired and endoscopy could also provide a solution though it is an invasive method.

  15. Gen-2 hand-held optical imager towards cancer imaging: reflectance and transillumination phantom studies. (United States)

    Gonzalez, Jean; Roman, Manuela; Hall, Michael; Godavarty, Anuradha


    Hand-held near-infrared (NIR) optical imagers are developed by various researchers towards non-invasive clinical breast imaging. Unlike these existing imagers that can perform only reflectance imaging, a generation-2 (Gen-2) hand-held optical imager has been recently developed to perform both reflectance and transillumination imaging. The unique forked design of the hand-held probe head(s) allows for reflectance imaging (as in ultrasound) and transillumination or compressed imaging (as in X-ray mammography). Phantom studies were performed to demonstrate two-dimensional (2D) target detection via reflectance and transillumination imaging at various target depths (1-5 cm deep) and using simultaneous multiple point illumination approach. It was observed that 0.45 cc targets were detected up to 5 cm deep during transillumination, but limited to 2.5 cm deep during reflectance imaging. Additionally, implementing appropriate data post-processing techniques along with a polynomial fitting approach, to plot 2D surface contours of the detected signal, yields distinct target detectability and localization. The ability of the gen-2 imager to perform both reflectance and transillumination imaging allows its direct comparison to ultrasound and X-ray mammography results, respectively, in future clinical breast imaging studies.

  16. Automated interpretation of optic nerve images: a data mining framework for glaucoma diagnostic support. (United States)

    Abidi, Syed S R; Artes, Paul H; Yun, Sanjan; Yu, Jin


    Confocal Scanning Laser Tomography (CSLT) techniques capture high-quality images of the optic disc (the retinal region where the optic nerve exits the eye) that are used in the diagnosis and monitoring of glaucoma. We present a hybrid framework, combining image processing and data mining methods, to support the interpretation of CSLT optic nerve images. Our framework features (a) Zernike moment methods to derive shape information from optic disc images; (b) classification of optic disc images, based on shape information, to distinguish between healthy and glaucomatous optic discs. We apply Multi Layer Perceptrons, Support Vector Machines and Bayesian Networks for feature sub-set selection and image classification; and (c) clustering of optic disc images, based on shape information, using Self-Organizing Maps to visualize sub-types of glaucomatous optic disc damage. Our framework offers an automated and objective analysis of optic nerve images that can potentially support both diagnosis and monitoring of glaucoma.

  17. Visible-Light Tomography Using an Optical Imaging-System

    NARCIS (Netherlands)

    Ingesson, L. C.; Koning, J. J.; Donne, A. J. H.; D.C. Schram,


    A system for tomography in the wavelength range 200-1 100 nm has been designed for the Rijnhuizen Tokamak Project (RTP). The plasma is viewed from five directions in one poloidal plane with a total of 80 detectors. An optical imaging system consisting of two spherical mirrors for each viewing direct

  18. Optical design of microlens array for CMOS image sensors (United States)

    Zhang, Rongzhu; Lai, Liping


    The optical crosstalk between the pixel units can influence the image quality of CMOS image sensor. In the meantime, the duty ratio of CMOS is low because of its pixel structure. These two factors cause the low detection sensitivity of CMOS. In order to reduce the optical crosstalk and improve the fill factor of CMOS image sensor, a microlens array has been designed and integrated with CMOS. The initial parameters of the microlens array have been calculated according to the structure of a CMOS. Then the parameters have been optimized by using ZEMAX and the microlens arrays with different substrate thicknesses have been compared. The results show that in order to obtain the best imaging quality, when the effect of optical crosstalk for CMOS is the minimum, the best distance between microlens array and CMOS is about 19.3 μm. When incident light successively passes through microlens array and the distance, obtaining the minimum facula is around 0.347 um in the active area. In addition, when the incident angle of the light is 0o 22o, the microlens array has obvious inhibitory effect on the optical crosstalk. And the anti-crosstalk distance between microlens array and CMOS is 0 μm 162 μm.

  19. Polymer Optical Fibre Sensors for Endoscopic Opto-Acoustic Imaging

    DEFF Research Database (Denmark)

    Broadway, Christian; Gallego, Daniel; Woyessa, Getinet;


    in existing publications. A great advantage can be obtained for endoscopy due to a small size and array potential to provide discrete imaging speed improvements. Optical fibre exhibits numerous advantages over conventional piezo-electric transducers, such as immunity from electromagnetic interference...

  20. Quantitative contrast-enhanced MR imaging of the optic nerve

    Energy Technology Data Exchange (ETDEWEB)

    Simon, J.H. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Rubinstein, D. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Brown, M. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Yuh, W. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Birch-Iensen, M. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Szumowski, J. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States); Stears, J. [Depts. of Radiology, Univ. of Colorado Health Sciences Center, Denver, CO (United States)]|[Iowa Univ., Iowa City, IA (United States)


    During the acute stages of optic neuritis damage to the blood-optic nerve barrier can be detected using i.v. paramagnetic contrast-enhanced MR imaging. Quantification of the enhancement pattern of the optic nerve, intraorbital fat and muscle was determined in 15 normal subjects using 3 fat-suppression MR imaging methods: T1-weighted spin-echo and spoiled gradient-echo sequences preceded by a flat-frequency selective pulse (FATSAT+SE and FATSAT+SPGR, respectively) and a pulse sequence combining CHOPPER fat suppression with a fat-frequency selective preparation pulse (HYBRID). Pre- and postcontrast-enhanced studies were acquired for FATSAT+SE and FATSAT+SPGR. There was no significant enhancement of the optic nerve by either method (mean increase of 0.96% and 5.3%, respectively), while there was significant enhancement in muscle (mean 118.2% and 108.2%, respectively; p<0.005) and fat (mean increase of 13% and 37%, respectively; p<0.05). Postcontrast optic nerve/muscle signal intensity ratios (mean, SD) were 0.51 (0.07), 0.58 (0.05) and 0.75 (0.05) for FATSAT+SE, FATSAT+SPGR and HYBRID, respectively. These results suggest a practical methodology and range of values for normal signal intensity increases and ratios of tissue signal that can be used as objective measures of optic neuritis for natural history studies and treatment trials. (orig.).

  1. Development of Multiscale Biological Image Data Analysis: Review of 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics, Santa Barbara, USA (BII06)


    Auer, Manfred; Peng, Hanchuan; Singh, Ambuj


    The 2006 International Workshop on Multiscale Biological Imaging, Data Mining and Informatics was held at Santa Barbara, on Sept 7–8, 2006. Based on the presentations at the workshop, we selected and compiled this collection of research articles related to novel algorithms and enabling techniques for bio- and biomedical image analysis, mining, visualization, and biology applications.

  2. Alternative optical concept for electron cyclotron emission imaging

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J. X., E-mail: [Department of Physics, University of California Berkeley, Berkeley, California 94720 (United States); Milbourne, T. [Department of Physics, College of William and Mary, Williamsburg, Virginia 23185 (United States); Bitter, M.; Delgado-Aparicio, L.; Dominguez, A.; Efthimion, P. C.; Hill, K. W.; Kramer, G. J.; Kung, C.; Pablant, N. A.; Tobias, B. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540 (United States); Kubota, S. [Department of Physics, University of California Los Angeles, Los Angeles, California 90095 (United States); Kasparek, W. [Department of Electrical Engineering, University of Stuttgart, Stuttgart (Germany); Lu, J. [Department of Physics, Chongqing University, Chongqing 400044 (China); Park, H. [Ulsan National Institute of Science and Technology, Ulsan 689-798 (Korea, Republic of)


    The implementation of advanced electron cyclotron emission imaging (ECEI) systems on tokamak experiments has revolutionized the diagnosis of magnetohydrodynamic (MHD) activities and improved our understanding of instabilities, which lead to disruptions. It is therefore desirable to have an ECEI system on the ITER tokamak. However, the large size of optical components in presently used ECEI systems have, up to now, precluded the implementation of an ECEI system on ITER. This paper describes a new optical ECEI concept that employs a single spherical mirror as the only optical component and exploits the astigmatism of such a mirror to produce an image with one-dimensional spatial resolution on the detector. Since this alternative approach would only require a thin slit as the viewing port to the plasma, it would make the implementation of an ECEI system on ITER feasible. The results obtained from proof-of-principle experiments with a 125 GHz microwave system are presented.

  3. Nanodiamond Landmarks for Subcellular Multimodal Optical and Electron Imaging

    CERN Document Server

    Zurbuchen, Mark A; Kohan, Sirus A; Leung, Belinda; Bouchard, Louis-S


    There is a growing need for biolabels that can be used in both optical and electron microscopies, are non-cytotoxic, and do not photobleach. Such biolabels could enable targeted nanoscale imaging of sub-cellular structures, and help to establish correlations between conjugation-delivered biomolecules and function. Here we demonstrate a subcellular multi-modal imaging methodology that enables localization of inert particulate probes, consisting of nanodiamonds having fluorescent nitrogen-vacancy centers. These are functionalized to target specific structures, and are observable by both optical and electron microscopies. Nanodiamonds targeted to the nuclear pore complex are rapidly localized in electron-microscopy diffraction mode to enable "zooming-in" to regions of interest for detailed structural investigations. Optical microscopies reveal nanodiamonds for in-vitro tracking or uptake-confirmation. The approach is general, works down to the single nanodiamond level, and can leverage the unique capabilities of...

  4. Intrinsic optical signal imaging of retinal physiology: a review (United States)

    Yao, Xincheng; Wang, Benquan


    Intrinsic optical signal (IOS) imaging promises to be a noninvasive method for high-resolution examination of retinal physiology, which can advance the study and diagnosis of eye diseases. While specialized optical instruments are desirable for functional IOS imaging of retinal physiology, in depth understanding of multiple IOS sources in the complex retinal neural network is essential for optimizing instrument designs. We provide a brief overview of IOS studies and relationships in rod outer segment suspensions, isolated retinas, and intact eyes. Recent developments of line-scan confocal and functional optical coherence tomography (OCT) instruments have allowed in vivo IOS mapping of photoreceptor physiology. Further improvements of the line-scan confocal and functional OCT systems may provide a feasible solution to pursue functional IOS mapping of human photoreceptors. Some interesting IOSs have already been detected in inner retinal layers, but better development of the IOS instruments and software algorithms is required to achieve optimal physiological assessment of inner retinal neurons.

  5. Human brain activity with functional NIR optical imager (United States)

    Luo, Qingming


    In this paper we reviewed the applications of functional near infrared optical imager in human brain activity. Optical imaging results of brain activity, including memory for new association, emotional thinking, mental arithmetic, pattern recognition ' where's Waldo?, occipital cortex in visual stimulation, and motor cortex in finger tapping, are demonstrated. It is shown that the NIR optical method opens up new fields of study of the human population, in adults under conditions of simulated or real stress that may have important effects upon functional performance. It makes practical and affordable for large populations the complex technology of measuring brain function. It is portable and low cost. In cognitive tasks subjects could report orally. The temporal resolution could be millisecond or less in theory. NIR method will have good prospects in exploring human brain secret.

  6. Primate retina imaging with polarization-sensitive optical coherence tomography (United States)

    Ducros, Mathieu G.; Marsack, Jason D.; Rylander, H. Grady; Thomsen, Sharon L.; Milner, Thomas E.


    Polarization-sensitive optical coherence tomography (PSOCT) is applied to determine the depth-resolved polarization state of light backreflected from the eye. The birefringence of the retinal nerve fiber layer (RNFL) was observed and measured from PSOCT images recorded postmortem in a Rhesus monkey. An image-processing algorithm was developed to identify birefringent regions in acquired PSOCT retinal images and automatically determine the thickness of the RNFL. Values of the RNFL thickness determined from histology and PSOCT were compared. PSOCT may provide a new method to determine RNFL thickness and birefringence for glaucoma diagnostics.

  7. In vivo multimodal nonlinear optical imaging of mucosal tissue (United States)

    Sun, Ju; Shilagard, Tuya; Bell, Brent; Motamedi, Massoud; Vargas, Gracie


    We present a multimodal nonlinear imaging approach to elucidate microstructures and spectroscopic features of oral mucosa and submucosa in vivo. The hamster buccal pouch was imaged using 3-D high resolution multiphoton and second harmonic generation microscopy. The multimodal imaging approach enables colocalization and differentiation of prominent known spectroscopic and structural features such as keratin, epithelial cells, and submucosal collagen at various depths in tissue. Visualization of cellular morphology and epithelial thickness are in excellent agreement with histological observations. These results suggest that multimodal nonlinear optical microscopy can be an effective tool for studying the physiology and pathology of mucosal tissue.

  8. Reflective optical imaging system for extreme ultraviolet wavelengths (United States)

    Viswanathan, V.K.; Newnam, B.E.


    A projection reflection optical system has two mirrors in a coaxial, four reflection configuration to reproduce the image of an object. The mirrors have spherical reflection surfaces to provide a very high resolution of object feature wavelengths less than 200 [mu]m, and preferably less than 100 [mu]m. An image resolution of features less than 0.05-0.1 [mu]m, is obtained over a large area field; i.e., 25.4 mm [times] 25.4 mm, with a distortion less than 0.1 of the resolution over the image field.

  9. Development of a Confocal Optical System Design for Molecular Imaging Applications of Biochip

    Directory of Open Access Journals (Sweden)

    Guoliang Huang


    Full Text Available A novel confocal optical system design and a dual laser confocal scanner have been developed to meet the requirements of highly sensitive detection of biomolecules on microarray chips, which is characterized by a long working distance (wd>3.0 mm, high numerical aperture (NA=0.72, and only 3 materials and 7 lenses used. This confocal optical system has a high scanning resolution, an excellent contrast and signal-to-noise ratio, and an efficiency of collected fluorescence of more than 2-fold better than that of other commercial confocal biochip scanners. The scanner is as equally good for the molecular imaging detection of enclosed biochips as for the detection of biological samples on a slide surface covered with a cover-slip glass. Some applications of gene and protein imagings using the dual laser confocal scanner are described.

  10. Optical imaging system-based real-time image saliency extraction method (United States)

    Zhao, Jufeng; Gao, Xiumin; Chen, Yueting; Feng, Huajun


    Saliency extraction has become a popular topic in imaging science. One of the challenges in image saliency extraction is to detect the saliency content efficiently with a full-resolution saliency map. Traditional methods only involve computer calculation and thus result in limitations in computational speed. An optical imaging system-based visual saliency extraction method is developed to solve this problem. The optical system is built by effectively implementing an optical Fourier process with a Fourier lens to form two frequency planes for further operation. The proposed method combines optical components and computer calculations and mainly relies on frequency selection with precise pinholes on the frequency planes to efficiently produce a saliency map. Comparison shows that the method is suitable for extracting salient information and operates in real time to generate a full-resolution saliency map with good boundaries.

  11. On the importance of image formation optics in the design of infrared spectroscopic imaging systems. (United States)

    Mayerich, David; van Dijk, Thomas; Walsh, Michael J; Schulmerich, Matthew V; Carney, P Scott; Bhargava, Rohit


    Infrared spectroscopic imaging provides micron-scale spatial resolution with molecular contrast. While recent work demonstrates that sample morphology affects the recorded spectrum, considerably less attention has been focused on the effects of the optics, including the condenser and objective. This analysis is extremely important, since it will be possible to understand effects on recorded data and provides insight for reducing optical effects through rigorous microscope design. Here, we present a theoretical description and experimental results that demonstrate the effects of commonly-employed cassegranian optics on recorded spectra. We first combine an explicit model of image formation and a method for quantifying and visualizing the deviations in recorded spectra as a function of microscope optics. We then verify these simulations with measurements obtained from spatially heterogeneous samples. The deviation of the computed spectrum from the ideal case is quantified via a map which we call a deviation map. The deviation map is obtained as a function of optical elements by systematic simulations. Examination of deviation maps demonstrates that the optimal optical configuration for minimal deviation is contrary to prevailing practice in which throughput is maximized for an instrument without a sample. This report should be helpful for understanding recorded spectra as a function of the optics, the analytical limits of recorded data determined by the optical design, and potential routes for optimization of imaging systems.

  12. a Novel Image Registration Algorithm for SAR and Optical Images Based on Virtual Points (United States)

    Ai, C.; Feng, T.; Wang, J.; Zhang, S.


    Optical image is rich in spectral information, while SAR instrument can work in both day and night and obtain images through fog and clouds. Combination of these two types of complementary images shows the great advantages of better image interpretation. Image registration is an inevitable and critical problem for the applications of multi-source remote sensing images, such as image fusion, pattern recognition and change detection. However, the different characteristics between SAR and optical images, which are due to the difference in imaging mechanism and the speckle noises in SAR image, bring great challenges to the multi-source image registration. Therefore, a novel image registration algorithm based on the virtual points, derived from the corresponding region features, is proposed in this paper. Firstly, image classification methods are adopted to extract closed regions from SAR and optical images respectively. Secondly, corresponding region features are matched by constructing cost function with rotate invariant region descriptors such as area, perimeter, and the length of major and minor axes. Thirdly, virtual points derived from corresponding region features, such as the centroids, endpoints and cross points of major and minor axes, are used to calculate initial registration parameters. Finally, the parameters are corrected by an iterative calculation, which will be terminated when the overlap of corresponding region features reaches its maximum. In the experiment, WordView-2 and Radasat-2 with 0.5 m and 4.7 m spatial resolution respectively, obtained in August 2010 in Suzhou, are used to test the registration method. It is shown that the multi-source image registration algorithm presented above is effective, and the accuracy of registration is up to pixel level.

  13. Perceptual image quality in normalized LOG domain for Adaptive Optics image post-processing (United States)

    Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Liu, Changhai; Gao, Weizhe


    Adaptive Optics together with subsequent post-processing techniques obviously improve the resolution of turbulencedegraded images in ground-based space objects detection and identification. The most common method for frame selection and stopping iteration in post-processing has always been subjective viewing of the images due to a lack of widely agreed-upon objective quality metric. Full reference metrics are not applicable for assessing the field data, no-reference metrics tend to perform poor sensitivity for Adaptive Optics images. In the present work, based on the Laplacian of Gaussian (LOG) local contrast feature, a nonlinear normalization is applied to transform the input image into a normalized LOG domain; a quantitative index is then extracted in this domain to assess the perceptual image quality. Experiments show this no-reference quality index is highly consistent with the subjective evaluation of input images for different blur degree and different iteration number.

  14. Optical imaging for stem cell differentiation to neuronal lineage. (United States)

    Hwang, Do Won; Lee, Dong Soo


    In regenerative medicine, the prospect of stem cell therapy holds great promise for the recovery of injured tissues and effective treatment of intractable diseases. Tracking stem cell fate provides critical information to understand and evaluate the success of stem cell therapy. The recent emergence of in vivo noninvasive molecular imaging has enabled assessment of the behavior of grafted stem cells in living subjects. In this review, we provide an overview of current optical imaging strategies based on cell- or tissue-specific reporter gene expression and of in vivo methods to monitor stem cell differentiation into neuronal lineages. These methods use optical reporters either regulated by neuron-specific promoters or containing neuron-specific microRNA binding sites. Both systems revealed dramatic changes in optical reporter imaging signals in cells differentiating into a neuronal lineage. The detection limit of weak promoters or reporter genes can be greatly enhanced by adopting a yeast GAL4 amplification system or an engineering-enhanced luciferase reporter gene. Furthermore, we propose an advanced imaging system to monitor neuronal differentiation during neurogenesis that uses in vivo multiplexed imaging techniques capable of detecting several targets simultaneously.

  15. Adaptive optics with pupil tracking for high resolution retinal imaging. (United States)

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris


    Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics.

  16. Optical Imaging for Stem Cell Differentiation to Neuronal Lineage

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Do Won; Lee, Dong Soo [Seoul National Univ., Seoul (Korea, Republic of)


    In regenerative medicine, the prospect of stem cell therapy hold great promise for the recovery of injured tissues and effective treatment of intractable diseases. Tracking stem cell fate provides critical information to understand and evaluate the success of stem cell therapy. The recent emergence of in vivo noninvasive molecular imaging has enabled assessment of the behavior of grafted stem cells in living subjects. In this review, we provide an overview of current optical imaging strategies based on cell or tissue specific reporter gene expression and of in vivo methods to monitor stem cell differentiation into neuronal lineages. These methods use optical reporters either regulated by neuron-specific promoters or containing neuron-specific microRNA binding sites. Both systems revealed dramatic changes in optical reporter imaging signals in cells differentiating a yeast GAL4 amplification system or an engineering-enhanced luciferase reported gene. Furthermore, we propose an advanced imaging system to monitor neuronal differentiation during neurogenesis that uses in vivo multiplexed imaging techniques capable of detecting several targets simultaneously.

  17. Stellar Intensity Interferometry: Prospects for sub-milliarcsecond optical imaging

    CERN Document Server

    Dravins, Dainis; Jensen, Hannes; Nuñez, Paul D


    Using kilometric arrays of air Cherenkov telescopes, intensity interferometry may increase the spatial resolution in optical astronomy by an order of magnitude, enabling images of rapidly rotating stars with structures in their circumstellar disks and winds, or mapping out patterns of nonradial pulsations across stellar surfaces. Intensity interferometry (pioneered by Hanbury Brown and Twiss) connects telescopes only electronically, and is practically insensitive to atmospheric turbulence and optical imperfections, permitting observations over long baselines and through large airmasses, also at short optical wavelengths. The required large telescopes with very fast detectors are becoming available as arrays of air Cherenkov telescopes, distributed over a few square km. Digital signal handling enables very many baselines to be synthesized, while stars are tracked with electronic time delays, thus synthesizing an optical interferometer in software. Simulated observations indicate limiting magnitudes around m(v)...

  18. A minimal optical trapping and imaging microscopy system.

    Directory of Open Access Journals (Sweden)

    Carmen Noemí Hernández Candia

    Full Text Available We report the construction and testing of a simple and versatile optical trapping apparatus, suitable for visualizing individual microtubules (∼25 nm in diameter and performing single-molecule studies, using a minimal set of components. This design is based on a conventional, inverted microscope, operating under plain bright field illumination. A single laser beam enables standard optical trapping and the measurement of molecular displacements and forces, whereas digital image processing affords real-time sample visualization with reduced noise and enhanced contrast. We have tested our trapping and imaging instrument by measuring the persistence length of individual double-stranded DNA molecules, and by following the stepping of single kinesin motor proteins along clearly imaged microtubules. The approach presented here provides a straightforward alternative for studies of biomaterials and individual biomolecules.

  19. Imaging of oral pathological tissue using optical coherence tomography (United States)

    Canjau, Silvana; Todea, Carmen; Sinescu, Cosmin; Duma, Virgil-Florin; Topala, Florin I.; Podoleanu, Adrian G.


    Oral squamous cell carcinoma (OSCC) constitutes 90% of oral cancer. Early detection is a cornerstone to improve survival. Interaction of light with tissues may highlight changes in tissue structure and metabolism. We propose optical coherence tomography (OCT), as a non-invasive diagnosis method, being a new high-resolution optical technique that permits tri-dimensional (3-D), real-time imaging of near surface abnormalities in complex tissues. In this study half of the excisional biopsy was directed to the pathologist and the other half was assigned for OCT investigation. Histopathology validated the results. Areas of OSCC of the buccal mucosa were identified in the OCT images. The elements obserced included extensive epithelial down-growth, the disruption of the basement membrane, with areas of erosion, an epithelial layer that was highly variable in thickness and invasion into the sub-epithelial layers. Therefore, OCT appears to be a highly promising imaging modality.

  20. Parametric imaging of viscoelasticity using optical coherence elastography (United States)

    Wijesinghe, Philip; McLaughlin, Robert A.; Sampson, David D.; Kennedy, Brendan F.


    We demonstrate imaging of soft tissue viscoelasticity using optical coherence elastography. Viscoelastic creep deformation is induced in tissue using step-like compressive loading and the resulting time-varying deformation is measured using phase-sensitive optical coherence tomography. From a series of co-located B-scans, we estimate the local strain rate as a function of time, and parameterize it using a four-parameter Kelvin-Voigt model of viscoelastic creep. The estimated viscoelastic strain and time constant are used to visualize viscoelastic creep in 2D, dual-parameter viscoelastograms. We demonstrate our technique on six silicone tissue-simulating phantoms spanning a range of viscoelastic parameters. As an example in soft tissue, we report viscoelastic contrast between muscle and connective tissue in fresh, ex vivo rat gastrocnemius muscle and mouse abdominal transection. Imaging viscoelastic creep deformation has the potential to provide complementary contrast to existing imaging modalities, and may provide greater insight into disease pathology.

  1. TV-L1 Optical Flow for Vector Valued Images

    DEFF Research Database (Denmark)

    Rakêt, Lars Lau; Roholm, Lars; Nielsen, Mads;


    a generalized algorithm that works on vector valued images, by means of a generalized projection step. We give examples of calculations of flows for a number of multi- dimensional constancy assumptions, e.g. gradient and RGB, and show how the developed methodology expands to any kind of vector valued images......The variational TV-L1 framework has become one of the most popular and successful approaches for calculating optical flow. One reason for the popularity is the very appealing properties of the two terms in the energy formulation of the problem, the robust L1-norm of the data fidelity term combined...... with the total variation (TV) regular- ization that smoothes the flow, but preserve strong discontinuities such as edges. Specifically the approach of Zach et al. [1] has provided a very clean and efficient algorithm for calculating TV-L1 optical flows between grayscale images. In this paper we propose...

  2. Image enhancement of optical images for binary system of melanocytes and keratinocytes (United States)

    Takanezawa, S.; Baba, A.; Sako, Y.; Ozaki, Y.; Date, A.; Toyama, K.; Morita, S.


    Automatic determination of the cell shapes of large numbers of melanocytes based on optical images of human skin models have been largely unsuccessful (the complexities introduced by dendrites and the melanin pigmentation over the keratinocytes to give unclear outlines). Here, we present an image enhancement procedure for enhancing the contrast of images with removing the non-uniformity of background. The brightness is normalized also for the non-uniform population density of melanocytes.

  3. Building 3D aerial image in photoresist with reconstructed mask image acquired with optical microscope (United States)

    Chou, C. S.; Tang, Y. P.; Chu, F. S.; Huang, W. C.; Liu, R. G.; Gau, T. S.


    Calibration of mask images on wafer becomes more important as features shrink. Two major types of metrology have been commonly adopted. One is to measure the mask image with scanning electron microscope (SEM) to obtain the contours on mask and then simulate the wafer image with optical simulator. The other is to use an optical imaging tool Aerial Image Measurement System (AIMSTM) to emulate the image on wafer. However, the SEM method is indirect. It just gathers planar contours on a mask with no consideration of optical characteristics such as 3D topography structures. Hence, the image on wafer is not predicted precisely. Though the AIMSTM method can be used to directly measure the intensity at the near field of a mask but the image measured this way is not quite the same as that on the wafer due to reflections and refractions in the films on wafer. Here, a new approach is proposed to emulate the image on wafer more precisely. The behavior of plane waves with different oblique angles is well known inside and between planar film stacks. In an optical microscope imaging system, plane waves can be extracted from the pupil plane with a coherent point source of illumination. Once plane waves with a specific coherent illumination are analyzed, the partially coherent component of waves could be reconstructed with a proper transfer function, which includes lens aberration, polarization, reflection and refraction in films. It is a new method that we can transfer near light field of a mask into an image on wafer without the disadvantages of indirect SEM measurement such as neglecting effects of mask topography, reflections and refractions in the wafer film stacks. Furthermore, with this precise latent image, a separated resist model also becomes more achievable.

  4. High-throughput Biological Cell Classification Featuring Real-time Optical Data Compression

    CERN Document Server

    Jalali, Bahram; Chen, Claire L


    High throughput real-time instruments are needed to acquire large data sets for detection and classification of rare events. Enabled by the photonic time stretch digitizer, a new class of instruments with record throughputs have led to the discovery of optical rogue waves [1], detection of rare cancer cells [2], and the highest analog-to-digital conversion performance ever achieved [3]. Featuring continuous operation at 100 million frames per second and shutter speed of less than a nanosecond, the time stretch camera is ideally suited for screening of blood and other biological samples. It has enabled detection of breast cancer cells in blood with record, one-in-a-million, sensitivity [2]. Owing to their high real-time throughput, instruments produce a torrent of data - equivalent to several 4K movies per second - that overwhelm data acquisition, storage, and processing operations. This predicament calls for technologies that compress images in optical domain and in real-time. An example of this, based on war...

  5. Optical slicing of large scenes by synthetic aperture integral imaging (United States)

    Navarro, Héctor; Saavedra, Genaro; Molina, Ainhoa; Martínez-Corral, Manuel; Martínez-Cuenca, Raúl; Javidi, Bahram


    Integral imaging (InI) technology was created with the aim of providing the binocular observers of monitors, or matrix display devices, with auto-stereoscopic images of 3D scenes. However, along the last few years the inventiveness of researches has allowed to find many other interesting applications of integral imaging. Examples of this are the application of InI in object recognition, the mapping of 3D polarization distributions, or the elimination of occluding signals. One of the most interesting applications of integral imaging is the production of views focused at different depths of the 3D scene. This application is the natural result of the ability of InI to create focal stacks from a single input image. In this contribution we present new algorithm for this optical slicing application, and show that it is possible the 3D reconstruction with improved lateral resolution.

  6. Nonlinear optical imaging characteristics in rat tail tendon (United States)

    Liu, N. R.; Zhang, X. Z.; Qiu, Y. S.; Chen, R.


    The aim of this study was to examine the characteristics of skeletal muscle fibers in tail tendons, explore the content of intrinsic components at different depths and ascertain the optimum excitation wavelength, which will help to establish a relationship between diagnosis and therapy and the tendon injury. A multiphoton microscopic imaging system was used to achieve the images and spectra via an imaging mode and a Lambda mode, respectively. This work demonstrates that the skeletal muscle fibers of the tail tendon are in good order. Second harmonic generation (SHG) and two-photon excited fluorescence (TPEF) signals originating from certain intrinsic components are varied with depth, and the SHG/TPEF intensity ratios are varied at different excitation wavelengths. Below 800 nm is the optimum for cell TPEF, while above 800 nm is the optimum for SHG. With the development of imaging techniques, a nonlinear optical imaging system will be helpful to represent the functional behaviors of tissue related to tendon injury.

  7. Serial Diffusion Tensor Imaging of the Optic Radiations after Acute Optic Neuritis

    Directory of Open Access Journals (Sweden)

    Scott C. Kolbe


    Full Text Available Previous studies have reported diffusion tensor imaging (DTI changes within the optic radiations of patients after optic neuritis (ON. We aimed to study optic radiation DTI changes over 12 months following acute ON and to study correlations between DTI parameters and damage to the optic nerve and primary visual cortex (V1. We measured DTI parameters [fractional anisotropy (FA, axial diffusivity (AD, radial diffusivity (RD, and mean diffusivity (MD] from the optic radiations of 38 acute ON patients at presentation and 6 and 12 months after acute ON. In addition, we measured retinal nerve fibre layer thickness, visual evoked potential amplitude, optic radiation lesion load, and V1 thickness. At baseline, FA was reduced and RD and MD were increased compared to control. Over 12 months, FA reduced in patients at an average rate of −2.6% per annum (control = −0.51%; p=0.006. Change in FA, RD, and MD correlated with V1 thinning over 12 months (FA: R=0.450, p=0.006; RD: R=-0.428, p=0.009; MD: R=-0.365, p=0.029. In patients with no optic radiation lesions, AD significantly correlated with RNFL thinning at 12 months (R=0.489, p=0.039. In conclusion, DTI can detect optic radiation changes over 12 months following acute ON that correlate with optic nerve and V1 damage.

  8. Organising multi-dimensional biological image information: the BioImage Database. (United States)

    Carazo, J M; Stelzer, E H; Engel, A; Fita, I; Henn, C; Machtynger, J; McNeil, P; Shotton, D M; Chagoyen, M; de Alarcón, P A; Fritsch, R; Heymann, J B; Kalko, S; Pittet, J J; Rodriguez-Tomé, P; Boudier, T


    Nowadays it is possible to unravel complex information at all levels of cellular organization by obtaining multi-dimensional image information. At the macromolecular level, three-dimensional (3D) electron microscopy, together with other techniques, is able to reach resolutions at the nanometer or subnanometer level. The information is delivered in the form of 3D volumes containing samples of a given function, for example, the electron density distribution within a given macromolecule. The same situation happens at the cellular level with the new forms of light microscopy, particularly confocal microscopy, all of which produce biological 3D volume information. Furthermore, it is possible to record sequences of images over time (videos), as well as sequences of volumes, bringing key information on the dynamics of living biological systems. It is in this context that work on BioImage started two years ago, and that its first version is now presented here. In essence, BioImage is a database specifically designed to contain multi-dimensional images, perform queries and interactively work with the resulting multi-dimensional information on the World Wide Web, as well as accomplish the required cross-database links. Two sister home pages of BioImage can be accessed at http://www. and

  9. Integrated optical coherence tomography and optical coherence microscopy imaging of human pathology (United States)

    Lee, Hsiang-Chieh; Zhou, Chao; Wang, Yihong; Aquirre, Aaron D.; Tsai, Tsung-Han; Cohen, David W.; Connolly, James L.; Fujimoto, James G.


    Excisional biopsy is the current gold standard for disease diagnosis; however, it requires a relatively long processing time and it may also suffer from unacceptable false negative rates due to sampling errors. Optical coherence tomography (OCT) is a promising imaging technique that provide real-time, high resolution and three-dimensional (3D) images of tissue morphology. Optical coherence microscopy (OCM) is an extension of OCT, combining both the coherence gating and the confocal gating techniques. OCM imaging achieves cellular resolution with deeper imaging depth compared to confocal microscopy. An integrated OCT/OCM imaging system can provide co-registered multiscale imaging of tissue morphology. 3D-OCT provides architectural information with a large field of view and can be used to find regions of interest; while OCM provides high magnification to enable cellular imaging. The integrated OCT/OCM system has an axial resolution of kidney (19), were imaged with OCT and OCM within 2 to 6 hours after excision. The images were compared with H & E histology to identify characteristic features useful for disease diagnosis. The feasibility of visualizing human pathology using integrated OCT/OCM was demonstrated in the pathology laboratory settings.

  10. Reflection Imaging X-Ray Laser Microscope (RIXRALM) and its biological applications. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Suckewer, S.


    The main stimulus for the development of the proposed microscope (RIXRALM) is the possibility to view the surface and near surface structure of biological materials, such as cell membranes at much higher resolution than an optical (confocal) microscope. Although the prediction resolution of RIXRALM was lower than a Scanning Electron Microscope (SEM), the possibility to obtain images of cells (membranes) in a more natural, hydrated state and, in many cases, without staining, made the idea of a reflection X-ray microscope very attractive. The specimen can be in an H{sub 2}O saturated He atmosphere at atmospheric pressure. As the image can be obtained quickly (nsec exposure, occurring within seconds of insertion into such an environment), the cell surface can be seen in a state which is very close to its natural condition. Besides, the short exposure time eliminates the effect of motional blurring on the images. Their X-ray reflection microscope fit well in the very large gap in the size of biological objects studied in light microscopy (sub-micron size) and electron microscope (down to a few nanometers size).

  11. Cellular resolution volumetric in vivo retinal imaging with adaptive optics-optical coherence tomography. (United States)

    Zawadzki, Robert J; Choi, Stacey S; Fuller, Alfred R; Evans, Julia W; Hamann, Bernd; Werner, John S


    Ultrahigh-resolution adaptive optics-optical coherence tomography (UHR-AO-OCT) instrumentation allowing monochromatic and chromatic aberration correction was used for volumetric in vivo retinal imaging of various retinal structures including the macula and optic nerve head (ONH). Novel visualization methods that simplify AO-OCT data viewing are presented, and include co-registration of AO-OCT volumes with fundus photography and stitching of multiple AO-OCT sub-volumes to create a large field of view (FOV) high-resolution volume. Additionally, we explored the utility of Interactive Science Publishing by linking all presented AO-OCT datasets with the OSA ISP software.

  12. Optical-parametric-amplification applications to complex images (United States)

    Vaughan, Peter M.


    Ultrafast optical pulses have many useful features. One in particular is their ability to exploit nonlinear processes due to their extremely short durations. We have used ultrafast optical pulses, primarily focused on the nonlinear processes of Polarization Gating and of Optical Parametric Amplification, one for measurement and the other for imaging purposes. For measurement, we have demonstrated a robust method of measurement to simultaneously measure both optical pulses used in a pump-probe type configuration. In these measurements, no initial information beyond the nonlinear interaction between the pulses is required. We refer to this method of pulse measurement as Double-Blind Polarization Gating FROG[1]. We have demonstrated this single-shot method for measuring two unknown pulses using one device. We have demonstrated this technique on three separate pulse pairs. We measured two Gaussian pulses with different amounts of chirp. We measured two double pulses with different pulse separations, and we have measured two extremely different pulses, where one was simple Gaussian and the other was a pulse train produced by an etalon. This method has no non-trivial ambiguities, has a reliable algorithm, and is automatically phase matched for all spectral bandwidths. In simulations[2], this method has proven to be extremely robust, measuring very complicated pulses with TBPs of ˜100 even in the presence of noise. In addition to pulse measurement, we have demonstrated the processes of Optical Parametric Amplification (OPA) applicability to imaging of complex objects[3]. We have done this where the Fourier transform plane is used during the interaction. We have amplified and wavelength converted a complex image. We report imaging of spatial features from 1.1 to 10.1 line pairs/millimeter (lp/mm) in the vertical dimension and from 2.0 to 16.0 lp/mm in the horizontal dimension. We observe a gain of ˜100, and, although our images were averaged over many shots, we used a

  13. Imaging patients with glaucoma using spectral-domain optical coherence tomography and optical microangiography (United States)

    Auyeung, Kris; Auyeung, Kelsey; Kono, Rei; Chen, Chieh-Li; Zhang, Qinqin; Wang, Ruikang K.


    In ophthalmology, a reliable means of diagnosing glaucoma in its early stages is still an open issue. Past efforts, including forays into fluorescent angiography (FA) and early optical coherence tomography (OCT) systems, to develop a potential biomarker for the disease have been explored. However, this development has been hindered by the inability of the current techniques to provide useful depth and microvasculature information of the optic nerve head (ONH), which have been debated as possible hallmarks of glaucoma progression. We reasoned that a system incorporating a spectral-domain OCT (SD-OCT) based Optical Microangiography (OMAG) system, could allow an effective, non-invasive methodology to evaluate effects on microvasculature by glaucoma. SD-OCT follows the principle of light reflection and interference to produce detailed cross-sectional and 3D images of the eye. OMAG produces imaging contrasts via endogenous light scattering from moving particles, allowing for 3D image productions of dynamic blood perfusion at capillary-level resolution. The purpose of this study was to investigate the optic cup perfusion (flow) differences in glaucomatous and normal eyes. Images from three normal and five glaucomatous subjects were analyzed our OCT based OMAG system for blood perfusion and structural images, allowing for comparisons. Preliminary results from blood flow analysis revealed reduced blood perfusion within the whole-depth region encompassing the Lamina Cribrosa in glaucomatous cases as compared to normal ones. We conclude that our OCT-OMAG system may provide promise and viability for glaucoma screening.

  14. Chemical shift selective magnetic resonance imaging of the optic nerve in patients with acute optic neuritis

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, H.B.W.; Thomsen, C.; Frederiksen, J.; Henriksen, O.; Olesen, J.

    Optic neuritis is often the first manifestion of multiple sclerosis (MS). Sixteen patients with acute optic neuritis and one patient with benign intracranial hypertension (BIH) were investigated by magnetic resonance imaging, using a chemical shift selective double spin echo sequence. In 3 of the 16 patients, abnormalities were seen. In one patient with bilateral symptoms, signal hyperintensity and swelling of the right side of the chiasm were found. In another patient the optic nerve was found diffusely enlarged with only a marginally increased signal in the second echo. In the third patient an area of signal hyperintensity and swelling was seen in the left optic nerve. In the patient with BIH the subarachnoid space which surrounds the optic nerves was enlarged. Even using this refined pulse sequence, avoiding the major artefact in imaging the optic nerve, the chemical shift artefact, lesions were only shown in 3/16 (19%) of the patients with optic neuritis. Nevertheless, the presented chemical shift selective double spin echo sequence may be of great value for detection of retrobulbar lesions.

  15. Method to improve the performance of reflectance diffuse optical imaging based on polygonal optical fibers arrangement

    Institute of Scientific and Technical Information of China (English)

    Weitao Li; Zhiyu Qian; Ting Li


    In order to improve the performance of reflectance diffuse optical imaging(rDOI),a novel polynomial geometry(PG)of optical fibers arrangement is proposed.Polynomial geometry is based on the hexagonal geometry(HG)and multicentered double-density(MD)mode.The overlapping sensitivity matrix,area ratio(AR),reconstruction image,two-absorber model,arid contrast-to-noise ratio(CNR)in different depths are used to evaluate the performance of PG.The other three geometries including HG,rectangular geometry(RG),and MD mode are also compared with PG.The deformation of the reconstruction images is evaluted by circular ratio(CR).The results prove that the proposed PG has high performance and minimum deformation in quality of reconstruction image in rDOI.

  16. Fluorescence-enhanced imaging using a novel hand-held based optical imager: phantom studies (United States)

    Ge, Jiajia; Zhu, Banghe; Regalado, Steven; Godavarty, Anuradha


    Near-infrared (NIR) optical imaging is an emerging noninvasive modality for breast cancer diagnosis. The currently available optical imaging systems towards tomography studies are limited either by instrument portability, patient comfort, or flexibility to image any given tissue volume. Hence, a novel hand-held probe based gain modulated intensified CCD camera imaging system is developed such that it can possibly overcome some of the above limitations. The unique features of this hand-held probe based optical imaging system are: (i) to perform simultaneous multiple point illumination and detection, thus decreasing the total imaging time and improving overall signal strength; (ii) to adapt to the tissue contours, thus decreasing the light leakage at contact surface; and (iii) to obtain trans-illumination measurements apart from reflectance measurements, thus improving the depth information. Phantom studies are performed to demonstrate the feasibility of performing fluorescence optical imaging under different target depths using cubical phantoms (10×6.5×10 cc). The effect of simultaneous multiple point illumination over sequential single point illumination is demonstrated from experimental phantom studies.

  17. Hybrid Microscopy: Enabling Inexpensive High-Performance Imaging through Combined Physical and Optical Magnifications (United States)

    Zhang, Yu Shrike; Chang, Jae-Byum; Alvarez, Mario Moisés; Trujillo-de Santiago, Grissel; Aleman, Julio; Batzaya, Byambaa; Krishnadoss, Vaishali; Ramanujam, Aishwarya Aravamudhan; Kazemzadeh-Narbat, Mehdi; Chen, Fei; Tillberg, Paul W.; Dokmeci, Mehmet Remzi; Boyden, Edward S.; Khademhosseini, Ali


    To date, much effort has been expended on making high-performance microscopes through better instrumentation. Recently, it was discovered that physical magnification of specimens was possible, through a technique called expansion microscopy (ExM), raising the question of whether physical magnification, coupled to inexpensive optics, could together match the performance of high-end optical equipment, at a tiny fraction of the price. Here we show that such “hybrid microscopy” methods—combining physical and optical magnifications—can indeed achieve high performance at low cost. By physically magnifying objects, then imaging them on cheap miniature fluorescence microscopes (“mini-microscopes”), it is possible to image at a resolution comparable to that previously attainable only with benchtop microscopes that present costs orders of magnitude higher. We believe that this unprecedented hybrid technology that combines expansion microscopy, based on physical magnification, and mini-microscopy, relying on conventional optics—a process we refer to as Expansion Mini-Microscopy (ExMM)—is a highly promising alternative method for performing cost-effective, high-resolution imaging of biological samples. With further advancement of the technology, we believe that ExMM will find widespread applications for high-resolution imaging particularly in research and healthcare scenarios in undeveloped countries or remote places.

  18. Partnerships Drive Informatics Solutions for Biological Imaging at Ocean Observatories (United States)

    Sosik, H. M.; Futrelle, J.; Maffei, A. R.


    In the big-data, era informatics-oriented partnerships are needed to achieve improved scientific results and understanding. Our teams' experience shows that formal methodologies to build interdisciplinary partnerships enable us to efficiently produce needed technological innovation. One-on-one partnerships between individual research scientists and informaticists provide a crucial building block for supporting larger, nested partnerships. We present one such partnership as an example. As ocean observatories mature, they produce data at a pace that threatens to overwhelm the capacity of individual researchers to manage and analyze it. Our multi-disciplinary team has addressed these challenges in the context of a study involving very large numbers (~1 billion) of images collected by Imaging FlowCytobot, an automated submersible flow cytometer that continuously images plankton at up to 10hz. These data provide novel insights into coastal ecosystem dynamics, including characterization of biological responses to environmental change and early warning of harmful algal blooms. In contrast with the traditional focus on technology adoption, we have instead emphasized building partnerships between oceanographers and computer scientists. In these partnerships we identify use cases, design solutions, develop prototypes, and refine them until they meet oceanographers' science needs. In doing so we have found that rapid and significant advances do not always require technological innovations, but rather effective communication, focus on science outcomes, and an iterative design and evaluation process. In this work we have adopted a methodology developed in the Tetherless World Constellation at Rensselaer Polytechnic Institute, a framework that has been used for several data-intensive earth science applications. The prototype system produced for Imaging FlowCytobot data provides simple and ubiquitous access to observational data and products via web services and includes a data

  19. Satellite Imaging with Adaptive Optics on a 1 M Telescope (United States)

    Bennet, F.; Price, I.; Rigaut, F.; Copeland, M.


    The Research School of Astronomy and Astrophysics at the Mount Stromlo Observatory in Canberra, Australia, have been developing adaptive optic (AO) systems for space situational awareness applications. We report on the development and demonstration of an AO system for satellite imaging using a 1 m telescope. The system uses the orbiting object as a natural guide star to measure atmospheric turbulence, and a deformable mirror to provide an optical correction. The AO system utilised modern, high speed and low noise EMCCD technology on both the wavefront sensor and imaging camera to achieve high performance, achieving a Strehl ratio in excess of 30% at 870 nm. Images are post processed with lucky imaging algorithms to further improve the final image quality. We demonstrate the AO system on stellar targets and Iridium satellites, achieving a near diffraction limited full width at half maximum. A specialised realtime controller allows our system to achieve a bandwidth above 100 Hz, with the wavefront sensor and control loop running at 2 kHz. The AO systems we are developing show how ground-based optical sensors can be used to manage the space environment. AO imaging systems can be used for satellite surveillance, while laser ranging can be used to determine precise orbital data used in the critical conjunction analysis required to maintain a safe space environment. We have focused on making this system compact, expandable, and versatile. We are continuing to develop this platform for other space situational awareness applications such as geosynchronous satellite astrometry, space debris characterisation, satellite imaging, and ground-to-space laser communication.

  20. Imaging of the Macula Indicates Early Completion of Structural Deficit in Autosomal-Dominant Optic Atrophy

    DEFF Research Database (Denmark)

    Rönnbäck, Cecilia; Milea, Dan; Larsen, Michael


    Optical coherence tomography (OCT) enables 3-dimensional imaging of the retina, including the layer of ganglion cells that supplies the optic nerve with its axons. We tested OCT as means of diagnosing and phenotyping autosomal-dominant optic atrophy (ADOA)....

  1. Nonlinear optical methods for the analysis of protein nanocrystals and biological tissues (United States)

    Dow, Ximeng You

    Structural biology underpins rational drug design and fundamental understanding of protein function. X-ray diffraction (XRD) has been the golden standard for solving for high-resolution protein structure. Second harmonic generation (SHG) microscopy has been developed by the Simpson lab as a sensitive, crystal-specific detection method for the identification of protein crystal and help optimize the crystallization condition. Protein nanocrystals has been widely used for structure determination of membrane proteins in serial femtosecond nanocrystallography. In this thesis work, novel nonlinear optical methods were developed to address the challenges associated with the detection and characterization of protein nanocrystals. SHG-correlation spectroscopy (SHG-CS) was developed to take advantage of the diffusing motion and retrieve the size distribution and crystal quality of the nanocrystals. Polarization-dependent SHG imaging technique was developed to measure the relative orientation as well as the internal structure of the sample. Two photon- excited fluorescence has been used in the Simpson lab as a complementary measurement besides the inherent SHG signal from the crystals. A novel instrumentation development was also introduced in this thesis work to greatly improve the speed of fluorescence lifetime imaging (FLIM).

  2. Biological inspiration in optics and photonics: harnessing nature's light manipulation strategies for multifunctional optical materials (Conference Presentation) (United States)

    Kolle, Mathias; Sandt, Joseph D.; Nagelberg, Sara N.; Zarzar, Lauren D.; Kreysing, Moritz; Vukusic, Peter


    The precise control of light-matter interactions is crucial for the majority of known biological organisms in their struggle to survive. Many species have evolved unique methods to manipulate light in their environment using a variety of physical effects including pigment-induced, spectrally selective absorption or light interference in photonic structures that consist of micro- and nano-periodic material morphologies. In their optical performance, many of the known biological photonic systems are subject to selection criteria not unlike the requirements faced in the development of novel optical technology. For this reason, biological light manipulation strategies provide inspiration for the creation of tunable, stimuli-responsive, adaptive material platforms that will contribute to the development of multifunctional surfaces and innovative optical technology. Biomimetic and bio-inspired approaches for the manufacture of photonic systems rely on self-assembly and bottom-up growth techniques often combined with conventional top-down manufacturing. In this regard, we can benefit in several ways from highly sophisticated material solutions that have convergently evolved in various organisms. We explore design concepts found in biological photonic architectures, seek to understand the mechanisms underlying morphogenesis of bio-optical systems, aim to devise viable manufacturing strategies that can benefit from insight in biological formation processes and the use of established synthetic routines alike, and ultimately strive to realize new photonic materials with tailor-made optical properties. This talk is focused on the identification of biological role model photonic architectures, a brief discussion of recently developed bio-inspired photonic structures, including mechano-sensitive color-tunable photonic fibers and reconfigurable fluid micro-lenses. Potentially, early-stage results in studying and harnessing the structure-forming capabilities of living cells that

  3. Optical nano-imaging of gate-tunable graphene plasmons. (United States)

    Chen, Jianing; Badioli, Michela; Alonso-González, Pablo; Thongrattanasiri, Sukosin; Huth, Florian; Osmond, Johann; Spasenović, Marko; Centeno, Alba; Pesquera, Amaia; Godignon, Philippe; Elorza, Amaia Zurutuza; Camara, Nicolas; García de Abajo, F Javier; Hillenbrand, Rainer; Koppens, Frank H L


    The ability to manipulate optical fields and the energy flow of light is central to modern information and communication technologies, as well as quantum information processing schemes. However, because photons do not possess charge, a way of controlling them efficiently by electrical means has so far proved elusive. A promising way to achieve electric control of light could be through plasmon polaritons—coupled excitations of photons and charge carriers—in graphene. In this two-dimensional sheet of carbon atoms, it is expected that plasmon polaritons and their associated optical fields can readily be tuned electrically by varying the graphene carrier density. Although evidence of optical graphene plasmon resonances has recently been obtained spectroscopically, no experiments so far have directly resolved propagating plasmons in real space. Here we launch and detect propagating optical plasmons in tapered graphene nanostructures using near-field scattering microscopy with infrared excitation light. We provide real-space images of plasmon fields, and find that the extracted plasmon wavelength is very short—more than 40 times smaller than the wavelength of illumination. We exploit this strong optical field confinement to turn a graphene nanostructure into a tunable resonant plasmonic cavity with extremely small mode volume. The cavity resonance is controlled in situ by gating the graphene, and in particular, complete switching on and off of the plasmon modes is demonstrated, thus paving the way towards graphene-based optical transistors. This successful alliance between nanoelectronics and nano-optics enables the development of active subwavelength-scale optics and a plethora of nano-optoelectronic devices and functionalities, such as tunable metamaterials, nanoscale optical processing, and strongly enhanced light–matter interactions for quantum devices and biosensing applications.

  4. Phi optics: from image to knowledge (Conference Presentation) (United States)

    Chiritescu, Catalin


    Optical microscopy of live cells and tissues provides the main insight for life science researchers in academia and bio-pharma. The cells have very small features, are transparent, and require long term observations (hours to days) to measure the effects of drugs and diseases. New technologies - under the umbrella term of Quantitative Phase Imaging (QPI) - have come to light in the past decade to challenge and complement the current state of the art solutions that use fluorophores. Phi Optics talk will outline their lessons learned in the process of bringing an academic idea to the commercial space.

  5. Raman imaging of biofilms using gold sputtered fiber optic probes (United States)

    Christopher, Christina Grace Charlet; Manoharan, Hariharan; Subrahmanyam, Aryasomayajula; Sai, V. V. Raghavendra


    In this work we report characterization of bacterial biofilm using gold sputtered optical fiber probe as substrates for confocal Raman spectroscopy measurements. The chemical composition and the heterogeneity of biofilms in the extracellular polymeric substances (EPS) was evaluated. The spatial distribution of bacterial biofilm on the substrates during their growth phase was studied using Raman imaging. Further, the influence of substrate's surface on bacterial adhesion was investigated by studying growth of biofilms on surfaces with hydrophilic and hydrophobic coatings. This study validates the use of gold sputtered optical fiber probes as SERS substrates in confocal microscopic configuration to identify and characterize clinically relevant biofilms.

  6. Joint Change Detection and Image Registration for Optical Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Wang Luo


    Full Text Available In this letter, a novel method is proposed for jointly unsupervised change detection and image registration over multi-temporal optical remote sensing images. An iterative energy minimization scheme is employed to extract the pixel opacity. Specifically, we extract the consistent points which provide the initial seed nodes and the feature nodes for random walker image segmentation and image registration, respectively. And the seed nodes will be updated according to the analysis of the changed and unchanged regions. Experimental results demonstrate that the proposed method can perform change detection as well as the state of the art methods. In particular, it can perform change detection rapidly and automatically over unregistered optical remote sensing images.

  7. Optical coherence tomography for retinal imaging in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Zimmermann H


    Full Text Available Hanna Zimmermann,1 Timm Oberwahrenbrock,1 Alexander U Brandt,1 Friedemann Paul,1–3 Jan Dörr1,2 1NeuroCure Clinical Research Center, 2Clinical and Experimental Multiple Sclerosis Research Center, 3Department of Neurology, Charité – Universitätsmedizin Berlin, Berlin, Germany Abstract: Visual disturbances caused by inflammatory and demyelinating processes of the visual system, mainly in the optic nerve, are a common symptom in multiple sclerosis (MS. Optical coherence tomography (OCT is a tool that is increasingly used for quantifying retinal damage in MS and other neurologic diseases. Based on spectral interferometry, it uses low-coherent infrared light to generate high-resolution spatial images of the retina. The retinal nerve fiber layer (RNFL consists of unmyelinated axons that form the optic nerve, and thus represents a part of the central nervous system. OCT allows for noninvasive measurements of RNFL thickness in micrometer resolution. With the help of OCT, researchers have managed to demonstrate that eyes of MS patients show distinct RNFL thinning after an event of acute optic neuritis in MS, and even subclinical damage in eyes with no previous optic neuritis. OCT is also a useful tool in terms of providing a differential diagnosis of MS toward, for example, neuromyelitis optica, a disease that usually shows stronger retinal thinning, or Susac syndrome, which is characterized by distinct patchy thinning of the inner retinal layers. RNFL thinning is associated with magnetic resonance imaging-derived measurements of the brain, such as whole-brain atrophy, gray and white matter atrophy, and optic radiation damage. These features suggest that OCT-derived retinal measurements are a complement for measuring central nervous system neurodegeneration in the context of clinical trials – for example, with neuroprotective substances. Keywords: visual function, multiple sclerosis, optic neuritis, retinal nerve fiber layer, neuromyelitis optica

  8. Novel image processing method study for a label-free optical biosensor (United States)

    Yang, Chenhao; Wei, Li'an; Yang, Rusong; Feng, Ying


    Optical biosensor is generally divided into labeled type and label-free type, the former mainly contains fluorescence labeled method and radioactive-labeled method, while fluorescence-labeled method is more mature in the application. The mainly image processing methods of fluorescent-labeled biosensor includes smooth filtering, artificial gridding and constant thresholding. Since some fluorescent molecules may influence the biological reaction, label-free methods have been the main developing direction of optical biosensors nowadays. The using of wider field of view and larger angle of incidence light path which could effectively improve the sensitivity of the label-free biosensor also brought more difficulties in image processing, comparing with the fluorescent-labeled biosensor. Otsu's method is widely applied in machine vision, etc, which choose the threshold to minimize the intraclass variance of the thresholded black and white pixels. It's capacity-constrained with the asymmetrical distribution of images as a global threshold segmentation. In order to solve the irregularity of light intensity on the transducer, we improved the algorithm. In this paper, we present a new image processing algorithm based on a reflectance modulation biosensor platform, which mainly comprises the design of sliding normalization algorithm for image rectification and utilizing the improved otsu's method for image segmentation, in order to implement automatic recognition of target areas. Finally we used adaptive gridding method extracting the target parameters for analysis. Those methods could improve the efficiency of image processing, reduce human intervention, enhance the reliability of experiments and laid the foundation for the realization of high throughput of label-free optical biosensors.

  9. Optical color-image encryption in the diffractive-imaging scheme (United States)

    Qin, Yi; Wang, Zhipeng; Pan, Qunna; Gong, Qiong


    By introducing the theta modulation technique into the diffractive-imaging-based optical scheme, we propose a novel approach for color image encryption. For encryption, a color image is divided into three channels, i.e., red, green and blue, and thereafter these components are appended by redundant data before being sent to the encryption scheme. The carefully designed optical setup, which comprises of three 4f optical architectures and a diffractive-imaging-based optical scheme, could encode the three plaintexts into a single noise-like intensity pattern. For the decryption, an iterative phase retrieval algorithm, together with a filter operation, is applied to extract the primary color images from the diffraction intensity map. Compared with previous methods, our proposal has successfully encrypted a color rather than grayscale image into a single intensity pattern, as a result of which the capacity and practicability have been remarkably enhanced. In addition, the performance and the security of it are also investigated. The validity as well as feasibility of the proposed method is supported by numerical simulations.

  10. Optical coherence tomography for embryonic imaging: a review (United States)

    Raghunathan, Raksha; Singh, Manmohan; Dickinson, Mary E.; Larin, Kirill V.


    Embryogenesis is a highly complex and dynamic process, and its visualization is crucial for understanding basic physiological processes during development and for identifying and assessing possible defects, malformations, and diseases. While traditional imaging modalities, such as ultrasound biomicroscopy, micro-magnetic resonance imaging, and micro-computed tomography, have long been adapted for embryonic imaging, these techniques generally have limitations in their speed, spatial resolution, and contrast to capture processes such as cardiodynamics during embryogenesis. Optical coherence tomography (OCT) is a noninvasive imaging modality with micrometer-scale spatial resolution and imaging depth up to a few millimeters in tissue. OCT has bridged the gap between ultrahigh resolution imaging techniques with limited imaging depth like confocal microscopy and modalities, such as ultrasound sonography, which have deeper penetration but poorer spatial resolution. Moreover, the noninvasive nature of OCT has enabled live imaging of embryos without any external contrast agents. We review how OCT has been utilized to study developing embryos and also discuss advances in techniques used in conjunction with OCT to understand embryonic development.

  11. Optical properties and cross-sections of biological aerosols (United States)

    Thrush, E.; Brown, D. M.; Salciccioli, N.; Gomes, J.; Brown, A.; Siegrist, K.; Thomas, M. E.; Boggs, N. T.; Carter, C. C.


    There is an urgent need to develop standoff sensing of biological agents in aerosolized clouds. In support of the Joint Biological Standoff Detection System (JBSDS) program, lidar systems have been a dominant technology and have shown significant capability in field tests conducted in the Joint Ambient Breeze Tunnel (JABT) at Dugway Proving Ground (DPG). The release of biological agents in the open air is forbidden. Therefore, indirect methods must be developed to determine agent cross-sections in order to validate sensor against biological agents. A method has been developed that begins with laboratory measurements of thin films and liquid suspensions of biological material to obtain the complex index of refraction from the ultraviolet (UV) to the long wave infrared (LWIR). Using that result and the aerosols' particle size distribution as inputs to Mie calculations yields the backscatter and extinction cross-sections as a function of wavelength. Recent efforts to model field measurements from the UV to the IR have been successful. Measurements with aerodynamic and geometric particle sizers show evidence of particle clustering. Backscatter simulations of these aerosols show these clustered particles dominate the aerosol backscatter and depolarization signals. In addition, these large particles create spectral signatures in the backscatter signal due to material absorption. Spectral signatures from the UV to the IR have been observed in simulations of field releases. This method has been demonstrated for a variety of biological simulant materials such as Ovalbumin (OV), Erwinia (EH), Bacillus atrophaeus (BG) and male specific bacteriophage (MS2). These spectral signatures may offer new methods for biological discrimination for both stand-off sensing and point detection systems.

  12. Label-free nonlinear optical imaging of mouse retina. (United States)

    He, Sicong; Ye, Cong; Sun, Qiqi; Leung, Christopher K S; Qu, Jianan Y


    A nonlinear optical (NLO) microscopy system integrating stimulated Raman scattering (SRS), two-photon excited fluorescence (TPEF) and second-harmonic generation (SHG) was developed to image fresh mouse retinas. The morphological and functional details of various retinal layers were revealed by the endogenous NLO signals. Particularly, high resolution label-free imaging of retinal neurons and nerve fibers in the ganglion cell and nerve fiber layers was achieved by capturing endogenous SRS and TPEF signals. In addition, the spectral and temporal analysis of TPEF images allowed visualization of different fluorescent components in the retinal pigment epithelium (RPE). Fluorophores with short TPEF lifetime, such as A2E, can be differentiated from other long-lifetime components in the RPE. The NLO imaging method would provide important information for investigation of retinal ganglion cell degeneration and holds the potential to study the biochemical processes of visual cycle in the RPE.

  13. Adaptive optics imaging of low and intermediate redshift quasars

    CERN Document Server

    Márquez, I; Theodore, B; Bremer, M; Monnet, G; Beuzit, J L


    We present the results of adaptive-optics imaging in the H and K bands of 12 low and intermediate redshift (z15.0) themselves as reference for the correction, have typical spatial resolution of FWHM~0.3 arcsec before deconvolution. The deconvolved H-band image of PG1700+514 has a spatial resolution of 0.16 arcsec and reveals a wealth of details on the companion and the host-galaxy. Four out of the twelve quasars have close companions and obvious signs of interactions. The two-dimensional images of three of the host-galaxies unambiguously reveal bars and spiral arms. The morphology of the other objects are difficult to determine from one dimensional surface brightness profile and deeper images are needed. Analysis of mocked data shows that elliptical galaxies are always recognized as such, whereas disk hosts can be missed for small disk scale lengths and large QSO contributions.

  14. Label-free imaging through nonlinear optical signals

    Directory of Open Access Journals (Sweden)

    Ling Tong


    Full Text Available Strong intrinsic nonlinear optical (NLO signals not only make nanostructures promising agents for bio-imaging, but also advance NLO microscopy for the study of interactions between nanomaterials and live cells. Single beam modalities such as multiphoton luminescence, second harmonic generation, and third harmonic generation provide a simple way to probe many types of nanostructures. As for more advanced modalities, photothermal heterodyne imaging provides improved detection sensitivity for smaller objects, and transient absorption microscopy provides structural information to distinguish metal from semiconducting carbon nanotubes, and eumelanin from pheomelanin. The four-wave mixing signal achieves chemical selectivity in the presence of either vibrational or electronic resonance, as used in coherent Raman scattering imaging of molecules and in electronically resonance enhanced four-wave mixing imaging of nanostructures.

  15. Imaged document information location and extraction using an optical correlator (United States)

    Stalcup, Bruce W.; Dennis, Phillip W.; Dydyk, Robert B.


    Today, the paper document is fast becoming a thing of the past. With the rapid development of fast, inexpensive computing and storage devices, many government and private organizations are archiving their documents in electronic form (e.g., personnel records, medical records, patents, etc.). Many of these organizations are converting their paper archives to electronic images, which are then stored in a computer database. Because of this, there is a need to efficiently organize this data into comprehensive and accessible information resources and provide for rapid access to the information contained within these imaged documents. To meet this need, Litton PRC and Litton Data Systems Division are developing a system, the Imaged Document Optical Correlation and Conversion System (IDOCCS), to provide a total solution to the problem of managing and retrieving textual and graphic information from imaged document archives. At the heart of IDOCCS, optical correlation technology provide a means for the search and retrieval of information from imaged documents. IDOCCS can be used to rapidly search for key words or phrases within the imaged document archives and has the potential to determine the types of languages contained within a document. In addition, IDOCCS can automatically compare an input document with the archived database to determine if it is a duplicate, thereby reducing the overall resources required to maintain and access the document database. Embedded graphics on imaged pages can also be exploited, e.g., imaged documents containing an agency's seal or logo can be singled out. In this paper, we present a description of IDOCCS as well as preliminary performance results and theoretical projections.

  16. Optic probe for multiple angle image capture and optional stereo imaging

    Energy Technology Data Exchange (ETDEWEB)

    Malone, Robert M.; Kaufman, Morris I.


    A probe including a multiple lens array is disclosed to measure velocity distribution of a moving surface along many lines of sight. Laser light, directed to the moving surface is reflected back from the surface and is Doppler shifted, collected into the array, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to the multiple lens array. Numerous fibers in a fiber array project numerous rays to establish many measurement points at numerous different locations. One or more lens groups may be replaced with imaging lenses so a stereo image of the moving surface can be recorded. Imaging a portion of the surface during initial travel can determine whether the surface is breaking up.

  17. Optical imaging process based on two-dimensional Fourier transform for synthetic aperture imaging ladar (United States)

    Sun, Zhiwei; Zhi, Ya'nan; Liu, Liren; Sun, Jianfeng; Zhou, Yu; Hou, Peipei


    The synthetic aperture imaging ladar (SAIL) systems typically generate large amounts of data difficult to compress with digital method. This paper presents an optical SAIL processor based on compensation of quadratic phase of echo in azimuth direction and two dimensional Fourier transform. The optical processor mainly consists of one phase-only liquid crystal spatial modulator(LCSLM) to load the phase data of target echo and one cylindrical lens to compensate the quadratic phase and one spherical lens to fulfill the task of two dimensional Fourier transform. We show the imaging processing result of practical target echo obtained by a synthetic aperture imaging ladar demonstrator. The optical processor is compact and lightweight and could provide inherent parallel and the speed-of-light computing capability, it has a promising application future especially in onboard and satellite borne SAIL systems.

  18. Adaptive optics scanning laser ophthalmoscope imaging: technology update

    Directory of Open Access Journals (Sweden)

    Merino D


    Full Text Available David Merino, Pablo Loza-Alvarez The Institute of Photonic Sciences (ICFO, The Barcelona Institute of Science and Technology, Castelldefels, Barcelona, Spain Abstract: Adaptive optics (AO retinal imaging has become very popular in the past few years, especially within the ophthalmic research community. Several different retinal techniques, such as fundus imaging cameras or optical coherence tomography systems, have been coupled with AO in order to produce impressive images showing individual cell mosaics over different layers of the in vivo human retina. The combination of AO with scanning laser ophthalmoscopy has been extensively used to generate impressive images of the human retina with unprecedented resolution, showing individual photoreceptor cells, retinal pigment epithelium cells, as well as microscopic capillary vessels, or the nerve fiber layer. Over the past few years, the technique has evolved to develop several different applications not only in the clinic but also in different animal models, thanks to technological developments in the field. These developments have specific applications to different fields of investigation, which are not limited to the study of retinal diseases but also to the understanding of the retinal function and vision science. This review is an attempt to summarize these developments in an understandable and brief manner in order to guide the reader into the possibilities that AO scanning laser ophthalmoscopy offers, as well as its limitations, which should be taken into account when planning on using it. Keywords: high-resolution, in vivo retinal imaging, AOSLO

  19. Space imaging infrared optical guidance for autonomous ground vehicle (United States)

    Akiyama, Akira; Kobayashi, Nobuaki; Mutoh, Eiichiro; Kumagai, Hideo; Yamada, Hirofumi; Ishii, Hiromitsu


    We have developed the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle based on the uncooled infrared camera and focusing technique to detect the objects to be evaded and to set the drive path. For this purpose we made servomotor drive system to control the focus function of the infrared camera lens. To determine the best focus position we use the auto focus image processing of Daubechies wavelet transform technique with 4 terms. From the determined best focus position we transformed it to the distance of the object. We made the aluminum frame ground vehicle to mount the auto focus infrared unit. Its size is 900mm long and 800mm wide. This vehicle mounted Ackerman front steering system and the rear motor drive system. To confirm the guidance ability of the Space Imaging Infrared Optical Guidance for Autonomous Ground Vehicle we had the experiments for the detection ability of the infrared auto focus unit to the actual car on the road and the roadside wall. As a result the auto focus image processing based on the Daubechies wavelet transform technique detects the best focus image clearly and give the depth of the object from the infrared camera unit.

  20. Electro-Optical Imaging Fourier-Transform Spectrometer (United States)

    Chao, Tien-Hsin; Zhou, Hanying


    An electro-optical (E-O) imaging Fourier-transform spectrometer (IFTS), now under development, is a prototype of improved imaging spectrometers to be used for hyperspectral imaging, especially in the infrared spectral region. Unlike both imaging and non-imaging traditional Fourier-transform spectrometers, the E-O IFTS does not contain any moving parts. Elimination of the moving parts and the associated actuator mechanisms and supporting structures would increase reliability while enabling reductions in size and mass, relative to traditional Fourier-transform spectrometers that offer equivalent capabilities. Elimination of moving parts would also eliminate the vibrations caused by the motions of those parts. Figure 1 schematically depicts a traditional Fourier-transform spectrometer, wherein a critical time delay is varied by translating one the mirrors of a Michelson interferometer. The time-dependent optical output is a periodic representation of the input spectrum. Data characterizing the input spectrum are generated through fast-Fourier-transform (FFT) post-processing of the output in conjunction with the varying time delay.

  1. Limitations of synthetic aperture laser optical feedback imaging

    CERN Document Server

    Glastre, Wilfried; Hugon, Olivier; De Chatellus, Hugues Guillet; Lacot, Eric


    In this paper we present the origin and the effect of amplitude and phase noise on Laser Optical Feedback Imaging (LOFI) associated with Synthetic Aperture (SA) imaging system. Amplitude noise corresponds to photon noise and acts as an additive noise, it can be reduced by increasing the global measurement time. Phase noise can be divided in three families: random, sinusoidal and drift phase noise; we show that it acts as a multiplicative noise. We explain how we can reduce it by making oversampling or multiple measurements depending on its type. This work can easily be extended to all SA systems (Radar, Laser or Terahertz), especially when raw holograms are acquired point by point.

  2. High Speed Optical Tomography System for Imaging Dynamic Transparent Media (United States)

    McMackin, Lenore; Hugo, Ronald J.; Pierson, R. E.; Truman, C. R.


    We describe the design and operation of a high speed optical tomography system for measuring two-dimensional images of a dynamic phase object at a rate of 5 kHz. Data from a set of eight Hartmann wavefront sensors is back-projected to produce phase images showing the details of the inner structure of a heated air flow. The tomographic reconstructions have a spatial resolution of approximately 2.0 mm and can measure temperature variations across the flow with an accuracy of about 0.7 C. Series of animated reconstructions at different downstream locations illustrate the development of flow structure and the effect of acoustic flow forcing.

  3. Optical Image Encryption with Simplified Fractional Hartley Transform

    Institute of Scientific and Technical Information of China (English)

    LI Xin-Xin; ZHAO Dao-Mu


    We present a new method for image encryption on the basis of simplified fractional Hartley transform (SFRHT). SFRHT is a real transform as Hartley transform (HT) and furthermore, superior to HT in virtue of the advantage that it can also append fractional orders as additional keys for the purpose of improving the system security to some extent. With this method, one can encrypt an image with an intensity-only medium such as a photographic film or a CCD camera by spatially incoherent or coherent illumination. The optical realization is then proposed and computer simulations are also performed to verify the feasibility of this method.

  4. Hyperspectral optical imaging of two different species of lepidoptera (United States)

    Medina, José Manuel; Nascimento, Sérgio Miguel Cardoso; Vukusic, Pete


    In this article, we report a hyperspectral optical imaging application for measurement of the reflectance spectra of photonic structures that produce structural colors with high spatial resolution. The measurement of the spectral reflectance function is exemplified in the butterfly wings of two different species of Lepidoptera: the blue iridescence reflected by the nymphalid Morpho didius and the green iridescence of the papilionid Papilio palinurus. Color coordinates from reflectance spectra were calculated taking into account human spectral sensitivity. For each butterfly wing, the observed color is described by a characteristic color map in the chromaticity diagram and spreads over a limited volume in the color space. The results suggest that variability in the reflectance spectra is correlated with different random arrangements in the spatial distribution of the scales that cover the wing membranes. Hyperspectral optical imaging opens new ways for the non-invasive study and classification of different forms of irregularity in structural colors.

  5. The application of interferometry to optical astronomical imaging. (United States)

    Baldwin, John E; Haniff, Christopher A


    In the first part of this review we survey the role optical/infrared interferometry now plays in ground-based astronomy. We discuss in turn the origins of astronomical interferometry, the motivation for its development, the techniques of its implementation, examples of its astronomical significance, and the limitations of the current generation of interferometric arrays. The second part focuses on the prospects for ground-based astronomical imaging interferometry over the near to mid-term (i.e. 10 years) at optical and near-infrared wavelengths. An assessment is made of the astronomical and technical factors which determine the optimal designs for imaging arrays. An analysis based on scientific capability, technical feasibility and cost argues for an array of large numbers of moderate-sized (2 m class) telescopes rather than one comprising a small number of much larger collectors.

  6. Hyperspectral optical imaging of two different species of lepidoptera

    Directory of Open Access Journals (Sweden)

    Vukusic Pete


    Full Text Available Abstract In this article, we report a hyperspectral optical imaging application for measurement of the reflectance spectra of photonic structures that produce structural colors with high spatial resolution. The measurement of the spectral reflectance function is exemplified in the butterfly wings of two different species of Lepidoptera: the blue iridescence reflected by the nymphalid Morpho didius and the green iridescence of the papilionid Papilio palinurus. Color coordinates from reflectance spectra were calculated taking into account human spectral sensitivity. For each butterfly wing, the observed color is described by a characteristic color map in the chromaticity diagram and spreads over a limited volume in the color space. The results suggest that variability in the reflectance spectra is correlated with different random arrangements in the spatial distribution of the scales that cover the wing membranes. Hyperspectral optical imaging opens new ways for the non-invasive study and classification of different forms of irregularity in structural colors.

  7. Digital optical tomography system for dynamic breast imaging. (United States)

    Flexman, Molly L; Khalil, Michael A; Al Abdi, Rabah; Kim, Hyun K; Fong, Christopher J; Desperito, Elise; Hershman, Dawn L; Barbour, Randall L; Hielscher, Andreas H


    Diffuse optical tomography has shown promising results as a tool for breast cancer screening and monitoring response to chemotherapy. Dynamic imaging of the transient response of the breast to an external stimulus, such as pressure or a respiratory maneuver, can provide additional information that can be used to detect tumors. We present a new digital continuous-wave optical tomography system designed to simultaneously image both breasts at fast frame rates and with a large number of sources and detectors. The system uses a master-slave digital signal processor-based detection architecture to achieve a dynamic range of 160 dB and a frame rate of 1.7 Hz with 32 sources, 64 detectors, and 4 wavelengths per breast. Included is a preliminary study of one healthy patient and two breast cancer patients showing the ability to identify an invasive carcinoma based on the hemodynamic response to a breath hold.

  8. Fourier transform acousto-optic imaging with a custom-designed CMOS smart-pixels array. (United States)

    Barjean, Kinia; Contreras, Kevin; Laudereau, Jean-Baptiste; Tinet, Éric; Ettori, Dominique; Ramaz, François; Tualle, Jean-Michel


    We report acousto-optic imaging (AOI) into a scattering medium using a Fourier Transform (FT) analysis to achieve axial resolution. The measurement system was implemented using a CMOS smart-pixels sensor dedicated to the real-time analysis of speckle patterns. This first proof-of-principle of FT-AOI demonstrates some of its potential advantages, with a signal-to-noise ratio comparable to the one obtained without axial resolution, and with an acquisition rate compatible with a use on living biological tissue.

  9. Estimation of aerosol optical properties from all-sky imagers (United States)

    Kazantzidis, Andreas; Tzoumanikas, Panagiotis; Salamalikis, Vasilios; Wilbert, Stefan; Prahl, Christoph


    Aerosols are one of the most important constituents in the atmosphere that affect the incoming solar radiation, either directly through absorbing and scattering processes or indirectly by changing the optical properties and lifetime of clouds. Under clear skies, aerosols become the dominant factor that affect the intensity of solar irradiance reaching the ground. It has been shown that the variability in direct normal irradiance (DNI) due to aerosols is more important than the one induced in global horizontal irradiance (GHI), while the uncertainty in its calculation is dominated by uncertainties in the aerosol optical properties. In recent years, all-sky imagers are used for the detection of cloud coverage, type and velocity in a bouquet of applications including solar irradiance resource and forecasting. However, information about the optical properties of aerosols could be derived with the same instrumentation. In this study, the aerosol optical properties are estimated with the synergetic use of all-sky images, complementary data from the Aerosol Robotic Network (AERONET) and calculations from a radiative transfer model. The area of interest is Plataforma Solar de Almería (PSA), Tabernas, Spain and data from a 5 month period are analyzed. The proposed methodology includes look-up-tables (LUTs) of diffuse sky radiance of Red (R), Green (G) and Blue (B) channels at several zenith and azimuth angles and for different atmospheric conditions (Angström α and β, single scattering albedo, precipitable water, solar zenith angle). Based on the LUTS, results from the CIMEL photometer at PSA were used to estimate the RGB radiances for the actual conditions at this site. The methodology is accompanied by a detailed evaluation of its robustness, the development and evaluation of the inversion algorithm (derive aerosol optical properties from RGB image values) and a sensitivity analysis about how the pre-mentioned atmospheric parameters affect the results.

  10. Polymer Optical Fibre Sensors for Endoscopic Opto-Acoustic Imaging

    DEFF Research Database (Denmark)

    Broadway, Christian; Gallego, Daniel; Woyessa, Getinet


    is the physical size of the device, allowing compatibility with current technology, while governing flexibility of the distal end of the endoscope based on the needs of the sensor. Polymer optical fibre (POF) presents a novel approach for endoscopic applications and has been positively discussed and compared...... in existing publications. A great advantage can be obtained for endoscopy due to a small size and array potential to provide discrete imaging speed improvements. Optical fibre exhibits numerous advantages over conventional piezo-electric transducers, such as immunity from electromagnetic interference...... and a higher resolution at small sizes. Furthermore, micro structured polymer optical fibres offer over 12 times the sensitivity of silica fibre. We present a polymer fibre Bragg grating ultrasound detector with a core diameter of 125 microns. We discuss the ultrasonic signals received and draw conclusions...

  11. Optical robotics in a biological micro-environment

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    with the use of joysticks or gaming devices. The fabrication of microstructures with nanometer sized features, for example a nano-needle, coupled with the real-time user interactive optical control allows a user to robotically actuate appended nanostructures depending on their intended function. These micro...

  12. A Stochastic Approach for Blurred Image Restoration and Optical Flow Computation on Field Image Sequence

    Institute of Scientific and Technical Information of China (English)

    高文; 陈熙霖


    The blur in target images caused by camera vibration due to robot motion or hand shaking and by object(s) moving in the background scene is different to deal with in the computer vision system.In this paper,the authors study the relation model between motion and blur in the case of object motion existing in video image sequence,and work on a practical computation algorithm for both motion analysis and blut image restoration.Combining the general optical flow and stochastic process,the paper presents and approach by which the motion velocity can be calculated from blurred images.On the other hand,the blurred image can also be restored using the obtained motion information.For solving a problem with small motion limitation on the general optical flow computation,a multiresolution optical flow algoritm based on MAP estimation is proposed. For restoring the blurred image ,an iteration algorithm and the obtained motion velocity are used.The experiment shows that the proposed approach for both motion velocity computation and blurred image restoration works well.

  13. Traffic Monitoring without single Car Detection from optical airborne Images


    Zeller, Klaus; Hinz, Stefan; Rosenbaum, Dominik; Leitloff, Jens; Reinartz, Peter


    This article describes several methods for traffic monitoring from airborne optical remote sensing data. These methods classify the traffic into free flowing traffic, traffic congestion and traffic jam. Furthermore a method is explained, which provides information about the average speed of dense traffic on a defined part of the road. All methods gather the information directly from image features, without the use of single vehicle detection. The classification of the traffic is done by st...

  14. RETROCAM: A Versatile Optical Imager for Synoptic Studies

    CERN Document Server

    Morgan, C W; De Poy, D L; Derwent, M; Kochanek, C S; Marshall, J L; O'Brien, T P; Pogge, R W; Morgan, Christopher W.; Byard, Paul L.; Derwent, Mark; Kochanek, Christopher S.; Brien, Thomas P. O'; Pogge, Richard W.


    We present RETROCAM, an auxiliary CCD camera that can be rapidly inserted into the optical beam of the MDM 2.4m telescope. The speed and ease of reconfiguring the telescope to use the imager and a straightforward user interface permit the camera to be used during the course of other observing programs. This in turn encourages RETROCAM's use for a variety of monitoring projects.

  15. Image density property of optical information recording microcapsule material (United States)

    Lai, Weidong; Li, Xiaowei; Li, Xinzheng; Fu, Guangsheng


    The microcapsules can act as novel optical functional material in which the optical recording substance such as color-forming substance, photoinitiator and prepolymer are encapsulated. In this paper, the microcapsules with average particle diameter of 300nm are prepared with interfacial polymerization method. The optical responding character of the microcapsule is analyzed based on IR spectra and image density technique. Results show that the microcapsule material encapsulated prepolymer TMPTA and photoinitiator Irgacure-ITX, TPO has thermal phase-change at 140°C, at which the penetrability of the microcapsule has the highest efficiency. With the increase of exposure time, the reduction in absorption intensities of the prepolymer TMPTA are observed at 1635cm-1 of C=C stretching and 898cm-1 of C-H stretching on the C=C molecular bond. Such a result can be ascribed to the double bond cleavage process of the prepolymer TMPTA is initiated by the optical-exposed photoinitiator, and superpolymer network is formed. The image density contrast between the unexposed and exposed microcapsule is enhanced with exposure time increased.

  16. Biocompatible Optically Transparent MEMS for Micromechanical Stimulation and Multimodal Imaging of Living Cells. (United States)

    Fior, Raffaella; Kwok, Jeanie; Malfatti, Francesca; Sbaizero, Orfeo; Lal, Ratnesh


    Cells and tissues in our body are continuously subjected to mechanical stress. Mechanical stimuli, such as tensile and contractile forces, and shear stress, elicit cellular responses, including gene and protein alterations that determine key behaviors, including proliferation, differentiation, migration, and adhesion. Several tools and techniques have been developed to study these mechanobiological phenomena, including micro-electro-mechanical systems (MEMS). MEMS provide a platform for nano-to-microscale mechanical stimulation of biological samples and quantitative analysis of their biomechanical responses. However, current devices are limited in their capability to perform single cell micromechanical stimulations as well as correlating their structural phenotype by imaging techniques simultaneously. In this study, a biocompatible and optically transparent MEMS for single cell mechanobiological studies is reported. A silicon nitride microfabricated device is designed to perform uniaxial tensile deformation of single cells and tissue. Optical transparency and open architecture of the device allows coupling of the MEMS to structural and biophysical assays, including optical microscopy techniques and atomic force microscopy (AFM). We demonstrate the design, fabrication, testing, biocompatibility and multimodal imaging with optical and AFM techniques, providing a proof-of-concept for a multimodal MEMS. The integrated multimodal system would allow simultaneous controlled mechanical stimulation of single cells and correlate cellular response.

  17. Narrow-band imaging optical chromocolonoscopy: Advantages and limitations

    Institute of Scientific and Technical Information of China (English)

    Fabian Emura; Yutaka Saito; Hiroaki Ikematsu


    Narrow-band imaging(NBI)is an innovative optical technology that modifies the center wavelength and bandwidth of an endoscope's light into narrow-band illumination of 415±30 nm.NBI markedly improves capillary pattern contrast and is an in vivo method for visualizing microvessel morphological changes in superficial neoplastic lesions.The scientific basis for NBI is that short wavelength light falls within the hemoglobin absorption band,thereby facilitating clearer visualization of vascular structures.Severalstudies have reported advantages and limitations of NBI colonoscopy in the colorectum.One difficulty in evaluating results,however,has been non-standardization of NBI systems(Sequential and non-sequential).Utilization of NBI technology has been increasing worldwide,but accurate pit pattern analysis and sufficient skill in magnifying colonoscopy are basic fundamentals required for proficiency in NBI diagnosis of colorectal lesions.Modern optical technology without proper image interpretation wastes resources,confuses untrained endoscopists and delays inter institutional validation studies.Training in the principles of"optical image-enhanced endoscopy"is needed to close the gap between technological advancements and their clinical usefulness.Currently available evidence indicates that NBI constitutes an effective and reliable alternative to chromocolonoscopy for in vivo visualization of vascular structures,but further study assessing reproducibility and effectiveness in the colorectum is ongoing at various medical centers.

  18. Wave optics approach for incoherent imaging simulation through distributed turbulence (United States)

    Underwood, Thomas A.; Voelz, David G.


    An approach is presented for numerically simulating incoherent imaging using coherent wave optics propagation methods. The approach employs averaging of irradiance from uncorrelated coherent waves to produce incoherent results. Novel aspects of the method include 1) the exploitation of a spatial windowing feature in the wave optics numerical propagator to limit the angular spread of the light and 2) a simple propagation scaling concept to avoid aliased field components after the focusing element. Classical linear systems theory is commonly used to simulate incoherent imaging when it is possible to incorporate aberrations and/or propagation medium characteristics into an optical transfer function (OTF). However, the technique presented here is useful for investigating situations such as "instantaneous" short-exposure imaging through distributed turbulence and phenomena like anisoplanatism that are not easily modeled with the typical linear systems theory. The relationships between simulation variables such as spatial sampling, source and aperture support, and intermediate focal plane are discussed and the requirement or benefits of choosing these in certain ways are demonstrated.

  19. In vivo intrinsic optical signal imaging of mouse retinas (United States)

    Wang, Benquan; Yao, Xincheng


    Intrinsic optical signal (IOS) imaging is a promising noninvasive method for advanced study and diagnosis of eye diseases. Before pursuing clinical applications, more IOS studies employing animal models are necessary to establish the relationship between IOS distortions and eye diseases. Ample mouse models are available for investigating the relationship between IOS distortions and eye diseases. However, in vivo IOS imaging of mouse retinas is challenging due to the small ocular lens (compared to frog eyes) and inevitable eye movements. We report here in vivo IOS imaging of mouse retinas using a custom-designed functional OCT. The OCT system provided high resolution (3 μm) and high speed (up to 500 frames/s) imaging of mouse retinas. An animal holder equipped with a custom designed ear bar and bite bar was used to minimize eye movement due to breathing and heartbeats. Residual eye movement in OCT images was further compensated by accurate image registration. Dynamic OCT imaging revealed rapid IOSs from photoreceptor outer segments immediately (IOS changes were also observed from inner retinal layers with delayed time courses compared to that of photoreceptor IOSs.

  20. End-to-End Image Simulator for Optical Imaging Systems: Equations and Simulation Examples

    Directory of Open Access Journals (Sweden)

    Peter Coppo


    Full Text Available The theoretical description of a simplified end-to-end software tool for simulation of data produced by optical instruments, starting from either synthetic or airborne hyperspectral data, is described and some simulation examples of hyperspectral and panchromatic images for existing and future design instruments are also reported. High spatial/spectral resolution images with low intrinsic noise and the sensor/mission specifications are used as inputs for the simulations. The examples reported in this paper show the capabilities of the tool for simulating target detection scenarios, data quality assessment with respect to classification performance and class discrimination, impact of optical design on image quality, and 3D modelling of optical performances. The simulator is conceived as a tool (during phase 0/A for the specification and early development of new Earth observation optical instruments, whose compliance to user’s requirements is achieved through a process of cost/performance trade-off. The Selex Galileo simulator, as compared with other existing image simulators for phase C/D projects of space-borne instruments, implements all modules necessary for a complete panchromatic and hyper spectral image simulation, and it allows excellent flexibility and expandability for new integrated functions because of the adopted IDL-ENVI software environment.

  1. CCD imaging for optical tomography of gel radiation dosimeters. (United States)

    Wolodzko, J G; Marsden, C; Appleby, A


    Several investigations have been carried out by a number of researchers over the past few years to evaluate the utility of imaging gel dosimeters for the three-dimensional measurement of radiation fields. These have been proposed to be of particular value in mapping radiation dose distributions associated with emerging and complex approaches to cancer treatment such as conformal (CRT), intensity modulated (IMRT), "gamma knife," and pencil beam radiotherapies. Imaging of the gels has been successfully accomplished with clinical MRI units and via laser-based optical scanning. However, neither of these methods is generally accessible to all potential users, limiting the broader study and implementation of this valuable tool. We report here the design, methodology, and results of a preliminary study carried out to evaluate the utility of a new, inexpensive, and simplified approach to tomographic imaging of gel radiation dosimeters. For the purpose of this initial investigation, an array of liquid scintillation vials was prepared, containing a ferrous sulphate xylenol orange (FSX) gelatin formulation. The FSX formulation undergoes a change in optical absorption characteristics following irradiation, and the resulting color change can be observed visually. The vials were irradiated individually to different doses. Three-dimensional imaging was accomplished by tomographic reconstruction from two-dimensional optical images acquired using a diffuse, fluorescent light source, a digital charge-coupled device camera, single-photon-emission-computed tomography software, and other simple components designed by the authors. The resulting transverse images were evaluated through a region-of-interest (ROI) analysis to obtain the average change in image density in each vial as a function of radiation dose. These measured ROI values were subjected to a linear regression analysis to fit them to a straight line, and to determine the goodness of fit. Results from multiple imaging trials

  2. Plasmophore sensitized imaging of ammonia release from biological tissues using optodes. (United States)

    Strömberg, Niklas; Hakonen, Aron


    A plasmophore sensitized optode was developed for imaging ammonia (NH(3)) concentrations in muscle tissues. The developed ammonia sensor and an equivalent non plasmophore version of the sensor were tested side by side to compare their limit of detection, dynamic range, reversibility and overall imaging quality. Bio-degradation patterns of ammonia release from lean porcine skeletal muscle were studied over a period of 11 days. We demonstrate that ammonia concentrations ranging from 10nM can be quantified reversibly with an optical resolution of 127 μm in a sample area of 25 mm × 35 mm. The plasmophore ammonia optode showed improved reversibility, less false pixels and a 2 nM ammonia detection limit compared to 200 nM for the non-plasmophore sensor. Main principles of the sensing mechanism include ammonia transfer over a gas permeable film, ammonia protonation, nonactin facilitated merocyanine-ammonium coextraction and plasmophore enhancement. The vast signal improvement is suggested to rely on solvatochroism, nanoparticle scattering and plasmonic interactions that are utilized constructively in a fluorescence ratio. In addition to fundamental medicinal and biological research applications in tissue physiology, reversible ammonia quantification will be possible for a majority of demanding imaging and non imaging applications such as monitoring of low ammonia background concentrations in air and non-invasive medicinal diagnosis through medical breath or saliva analysis. The nanoparticle doped sensor constitutes a highly competitive technique for ammonia sensing in complex matrixes and the general sensing scheme offers new possibilities for the development of artificial optical noses and tongues.

  3. First-in-human clinical trials of imaging devices: an example from optical imaging. (United States)

    Gibbs-Strauss, Summer L; Rosenberg, Mireille; Clough, Barbara L; Troyan, Susan L; Frangioni, John V


    Clinical translation of scientific discoveries is often the long-term goal of academic medical research. However, this goal is not always realized due to the complicated path between bench research and clinical use. In this review, we outline the fundamental steps required for first-in-human testing of a new imaging device, and use the FLARE() (Fluorescence-Assisted Resection and Exploration) near-infrared fluorescence optical imaging platform as an example.

  4. Optical properties of dissolved organic matter (DOM): Effects of biological and photolytic degradation (United States)

    Hansen, Angela; Kraus, Tamara; Pellerin, Brian; Fleck, Jacob; Downing, Bryan D.; Bergamaschi, Brian


    Advances in spectroscopic techniques have led to an increase in the use of optical properties (absorbance and fluorescence) to assess dissolved organic matter (DOM) composition and infer sources and processing. However, little information is available to assess the impact of biological and photolytic processing on the optical properties of original DOM source materials. We measured changes in commonly used optical properties and indices in DOM leached from peat soil, plants, and algae following biological and photochemical degradation to determine whether they provide unique signatures that can be linked to original DOM source. Changes in individual optical parameters varied by source material and process, with biodegradation and photodegradation often causing values to shift in opposite directions. Although values for different source materials overlapped at the end of the 111-day lab experiment, multivariate statistical analyses showed that unique optical signatures could be linked to original DOM source material even after degradation, with 17 optical properties determined by discriminant analysis to be significant (p<0.05) in distinguishing between DOM source and environmental processing. These results demonstrate that inferring the source material from optical properties is possible when parameters are evaluated in combination even after extensive biological and photochemical alteration.

  5. Adaptive optics scanning laser ophthalmoscope imaging: technology update. (United States)

    Merino, David; Loza-Alvarez, Pablo


    Adaptive optics (AO) retinal imaging has become very popular in the past few years, especially within the ophthalmic research community. Several different retinal techniques, such as fundus imaging cameras or optical coherence tomography systems, have been coupled with AO in order to produce impressive images showing individual cell mosaics over different layers of the in vivo human retina. The combination of AO with scanning laser ophthalmoscopy has been extensively used to generate impressive images of the human retina with unprecedented resolution, showing individual photoreceptor cells, retinal pigment epithelium cells, as well as microscopic capillary vessels, or the nerve fiber layer. Over the past few years, the technique has evolved to develop several different applications not only in the clinic but also in different animal models, thanks to technological developments in the field. These developments have specific applications to different fields of investigation, which are not limited to the study of retinal diseases but also to the understanding of the retinal function and vision science. This review is an attempt to summarize these developments in an understandable and brief manner in order to guide the reader into the possibilities that AO scanning laser ophthalmoscopy offers, as well as its limitations, which should be taken into account when planning on using it.

  6. Test for optical systems in laser projection imaging for PCB (United States)

    Qin, Ouyang; Zhou, Jinyun; Lei, Liang; Lin, Qinghua


    Projection imaging is one of the most important steps in the fabrication of Printed Circuit Board. In order to meet the increasing demand for higher resolution, speed and larger area of imaging, a novel Laser Projection Imaging (LPI) has been developed to take the place of the conventional Hg lamp exposure. We set up a system with resolution 10μm over large exposure area of 460mm×610mm on substrate materials. The system is available by the combination of three main parts: an XeF excimer laser with a wavelength of 351nm and single pulse energy of 120mJ, an illumination system with numerical aperture (NA) value of 0.02, and a double telecentric optical projection lens with NA value of 0.025. Such designs can theoretically meet the demand of actual lithography. However, experiments have shown that the propagation loss ratio of laser power from the light source to the substrate can be up to 50% or more so as to hardly achieve the expected results. In this paper, we present our results of experiments under different conditions on laser projection imaging equipment, and meanwhile, parameters such as gas lifetime, pulse repetition rate, exposure dose, as well as the optical lose of quartz microlens array are analyzed. Finally, we acquired the optimum exposure parameters.

  7. Integrated optics in an electrically scanned imaging Fourier transform spectrometer (United States)

    Breckinridge, James B. (Inventor); Ocallaghan, Fred G. (Inventor)


    An efficient, lightweight and stable, Fourier transform spectrometer was developed. The mechanical slide mechanism needed to create a path difference was eliminated by the use of retro-reflecting mirrors in a monolithic interferometer assembly in which the mirrors are not at 90 degrees to the propagation vector of the radiation, but rather at a small angle. The resulting plane wave fronts create a double-sided inteferogram of the source irradiance distribution which is detected by a charge-coupled device image sensor array. The position of each CCD pixel in the array is an indication of the path difference between the two retro-reflecting mirrors in the monolithic optical structure. The Fourier transform of the signals generated by the image sensor provide the spectral irradiance distribution of the source. For imaging, the interferometer assembly scans the source of irradiation by moving the entire instrument, such as would occur if it was fixedly mounted to a moving platform, i.e., a spacecraft. During scanning, the entrace slot to the monolithic optical structure sends different pixels to corresponding interferograms detected by adjacent columns of pixels of the image sensor.

  8. Deep optical images of Malin 1 reveal new features

    CERN Document Server

    Galaz, Gaspar; Suc, Vincent; Busta, Luis; Lizana, Guadalupe; Infante, Leopoldo; Royo, Santiago


    We present Megacam deep optical images (g and r) of Malin 1 obtained with the 6.5m Magellan/Clay telescope, detecting structures down to ~ 28 B mag arcsec-2. In order to enhance galaxy features buried in the noise, we use a noise reduction filter based on the total generalized variation regularizator. This method allows us to detect and resolve very faint morphological features, including spiral arms, with a high visual contrast. For the first time, we can appreciate an optical image of Malin 1 and its morphology in full view. The images provide unprecedented detail, compared to those obtained in the past with photographic plates and CCD, including HST imaging. We detect two peculiar features in the disk/spiral arms. The analysis suggests that the first one is possibly a background galaxy, and the second is an apparent stream without a clear nature, but could be related to the claimed past interaction between Malin 1 and the galaxy SDSSJ123708.91 + 142253.2. Malin 1 exhibits features suggesting the presence o...

  9. Joint Applied Optics and Chinese Optics Letters Feature Introduction: Digital Holography and 3D Imaging

    Institute of Scientific and Technical Information of China (English)

    Ting-Chung Poon; Changhe Zhou; Toyohiko Yatagai; Byoungho Lee; Hongchen Zhai


    This feature issue is the fifth installment on digital holography since its inception four years ago.The last four issues have been published after the conclusion of each Topical Meeting "Digital Holography and 3D imaging (DH)." However,this feature issue includes a new key feature-Joint Applied Optics and Chinese Optics Letters Feature Issue.The DH Topical Meeting is the world's premier forum for disseminating the science and technology geared towards digital holography and 3D information processing.Since the meeting's inception in 2007,it has steadily and healthily grown to 130 presentations this year,held in Tokyo,Japan,May 2011.

  10. Practical optical interferometry imaging at visible and infrared wavelengths

    CERN Document Server

    Buscher, David F


    Optical interferometry is a powerful technique to make images on angular scales hundreds of times smaller than is possible with the largest telescopes. This concise guide provides an introduction to the technique for graduate students and researchers who want to make interferometric observations and acts as a reference for technologists building new instruments. Starting from the principles of interference, the author covers the core concepts of interferometry, showing how the effects of the Earth's atmosphere can be overcome using closure phase, and the complete process of making an observation, from planning to image reconstruction. This rigorous approach emphasizes the use of rules-of-thumb for important parameters such as the signal-to-noise ratios, requirements for sampling the Fourier plane and predicting image quality. The handbook is supported by web resources, including the Python source code used to make many of the graphs, as well as an interferometry simulation framework, available at www.cambridg...

  11. Optimization of pediatric chest radiographic images using optical densities ratio

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Rafael T.F.; Miranda, Jose R.A. [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Botucatu, SP (Brazil). Inst. de Biociencias de Botucatu; Pina, Diana R. [Faculdade de Medicina de Botucatu (UNESP), Botucatu, SP (Brazil). Hospital das Clinicas. Dept. de Doencas Tropicais e Diagnostico por Imagem; Duarte, Sergio B. [Centro Brasileiro de Pesquisas Fisicas (CBPF/MCT), Rio de Janeiro, RJ (Brazil)


    The aim of this study is the optimization of radiographic images for the pediatric patients in the age range between 0 and 1 years old, through Optical Density Ratio (ODR), considering that pediatric patients are overexposed to radiation in the repeated attempts to obtain radiographic images considered of good quality. The optimization of radiographic techniques was carried out with the RAP-PEPP (Realistic Analytical Phantom coupled to homogeneous Phantom Equivalent to Pediatric Patient) phantom in two incubators and one cradle. The data show that the clinical routine radiographic techniques generate low-quality images at up to 18.8% when evaluated by the ODRs, and increases in doses up to 60% when compared to the optimized techniques doses. (author)

  12. Optical coherence tomography for imaging of skin and skin diseases

    DEFF Research Database (Denmark)

    Mogensen, Mette; Thrane, Lars; Jørgensen, Thomas Martini


    Optical coherence tomography (OCT) is an emerging imaging technology based on light reflection. It provides real-time images with up to 2-mm penetration into the skin and a resolution of approximately 10 μm. It is routinely used in ophthalmology. The normal skin and its appendages have been studied......, as have many diseases. The method can provide accurate measures of epidermal and nail changes in normal tissue. Skin cancer and other tumors, as well as inflammatory diseases, have been studied and good agreement found between OCT images and histopathological architecture. OCT also allows noninvasive...... monitoring of morphologic changes in skin diseases and may have a particular role in the monitoring of medical treatment of nonmelanoma skin cancer. The technology is however still evolving and continued technological development will necessitate an ongoing evaluation of its diagnostic accuracy. Several...

  13. Imaging port wine stains by fiber optical coherence tomography (United States)

    Zhao, Shiyong; Gu, Ying; Xue, Ping; Guo, Jin; Shen, Tingmei; Wang, Tianshi; Huang, Naiyan; Zhang, Li; Qiu, Haixia; Yu, Xin; Wei, Xunbin


    We develop a fiber optical coherence tomography (OCT) system in the clinical utility of imaging port wine stains (PWS). We use our OCT system on 41 patients with PWS to document the difference between PWS skin and contralateral normal skin. The system, which operates at 4 frames/s with axial and transverse resolutions of 10 and 9 μm, respectively, in the skin tissue, can clearly distinguish the dilated dermal blood vessels from normal tissue. We present OCT images of patients with PWS and normal human skin. We obtain the structural parameters, including epidermal thickness and diameter and depth of dilated blood vessels. We demonstrate that OCT may be a useful tool for the noninvasive imaging of PWS. It may help determine the photosensitizer dose and laser parameters in photodynamic therapy for treating port wine stains.

  14. Optical imaging of L723: the structure of HH 223

    CERN Document Server

    López, R; Gómez, G; Riera, A


    We imaged the Lynds 723 dark nebula (L723) with the aim of studying the morphology of the Herbig-Haro object HH 223 and other line-emission nebula detected in the region. We obtained deep narrow-band images in the Halpha and [SII] lines and in the continuum nearby Halpha of a field of ~5' of the L723 dark nebula centered on HH 223. The Halpha and [SII] images reveal the detailed morphology of HH 223, unresolved in previous optical images. Both images show a quite complex knotty, wiggling structure embedded in a low-emission nebula. Comparison between the [SII] and Halpha fluxes of the knots are indicative of variations in the excitation conditions through HH 223. In addition, several other faint nebula are detected in Halpha a few arcmin to the SE and to the NW of HH 223, all of them lying projected onto the east-west pair of lobes of the quadrupolar CO outflow. Comparison between the Halpha and the continuum images confirms the HH-like nature of the Vrba object V83, while the Vrba objects V84 and V85 are ide...

  15. Progress of MEMS Scanning Micromirrors for Optical Bio-Imaging

    Directory of Open Access Journals (Sweden)

    Lih Y. Lin


    Full Text Available Microelectromechanical systems (MEMS have an unmatched ability to incorporate numerous functionalities into ultra-compact devices, and due to their versatility and miniaturization, MEMS have become an important cornerstone in biomedical and endoscopic imaging research. To incorporate MEMS into such applications, it is critical to understand underlying architectures involving choices in actuation mechanism, including the more common electrothermal, electrostatic, electromagnetic, and piezoelectric approaches, reviewed in this paper. Each has benefits and tradeoffs and is better suited for particular applications or imaging schemes due to achievable scan ranges, power requirements, speed, and size. Many of these characteristics are fabrication-process dependent, and this paper discusses various fabrication flows developed to integrate additional optical functionality beyond simple lateral scanning, enabling dynamic control of the focus or mirror surface. Out of this provided MEMS flexibility arises some challenges when obtaining high resolution images: due to scanning non-linearities, calibration of MEMS scanners may become critical, and inherent image artifacts or distortions during scanning can degrade image quality. Several reviewed methods and algorithms have been proposed to address these complications from MEMS scanning. Given their impact and promise, great effort and progress have been made toward integrating MEMS and biomedical imaging.

  16. Functional connectivity of the rodent brain using optical imaging (United States)

    Guevara Codina, Edgar

    The aim of this thesis is to apply functional connectivity in a variety of animal models, using several optical imaging modalities. Even at rest, the brain shows high metabolic activity: the correlation in slow spontaneous fluctuations identifies remotely connected areas of the brain; hence the term "functional connectivity". Ongoing changes in spontaneous activity may provide insight into the neural processing that takes most of the brain metabolic activity, and so may provide a vast source of disease related changes. Brain hemodynamics may be modified during disease and affect resting-state activity. The thesis aims to better understand these changes in functional connectivity due to disease, using functional optical imaging. The optical imaging techniques explored in the first two contributions of this thesis are Optical Imaging of Intrinsic Signals and Laser Speckle Contrast Imaging, together they can estimate the metabolic rate of oxygen consumption, that closely parallels neural activity. They both have adequate spatial and temporal resolution and are well adapted to image the convexity of the mouse cortex. In the last article, a depth-sensitive modality called photoacoustic tomography was used in the newborn rat. Optical coherence tomography and laminar optical tomography were also part of the array of imaging techniques developed and applied in other collaborations. The first article of this work shows the changes in functional connectivity in an acute murine model of epileptiform activity. Homologous correlations are both increased and decreased with a small dependence on seizure duration. These changes suggest a potential decoupling between the hemodynamic parameters in resting-state networks, underlining the importance to investigate epileptic networks with several independent hemodynamic measures. The second study examines a novel murine model of arterial stiffness: the unilateral calcification of the right carotid. Seed-based connectivity analysis

  17. Multi-aperture optics as a universal platform for computational imaging (United States)

    Tanida, Jun


    Computational imaging is a novel imaging framework based on optical encoding and computational decoding. To avoid a heuristic design that depends on the particular problem to be solved, multi-aperture optics is useful as a universal platform for optical encoding. In this paper, the fundamental properties of multi-aperture optics are summarized. Then some examples of interesting functions implemented by multi-aperture optics are explained, together with some effective applications.

  18. Development of Two Color Fluorescent Imager and Integrated Fluidic System for Nanosatellite Biology Applications (United States)

    Wu, Diana Terri; Ricco, Antonio Joseph; Lera, Matthew P.; Timucin, Linda R.; Parra, Macarena P.


    Nanosatellites offer frequent, low-cost space access as secondary payloads on launches of larger conventional satellites. We summarize the payload science and technology of the Microsatellite in-situ Space Technologies (MisST) nanosatellite for conducting automated biological experiments. The payload (two fused 10-cm cubes) includes 1) an integrated fluidics system that maintains organism viability and supports growth and 2) a fixed-focus imager with fluorescence and scattered-light imaging capabilities. The payload monitors temperature, pressure and relative humidity, and actively controls temperature. C. elegans (nematode, 50 m diameter x 1 mm long) was selected as a model organism due to previous space science experience, its completely sequenced genome, size, hardiness, and the variety of strains available. Three strains were chosen: two green GFP-tagged strains and one red tdTomato-tagged strain that label intestinal, nerve, and pharyngeal cells, respectively. The integrated fluidics system includes bioanalytical and reservoir modules. The former consists of four 150 L culture wells and a 4x5 mm imaging zone the latter includes two 8 mL fluid reservoirs for reagent and waste storage. The fluidic system is fabricated using multilayer polymer rapid prototyping: laser cutting, precision machining, die cutting, and pressure-sensitive adhesives it also includes eight solenoid-operated valves and one mini peristaltic pump. Young larval-state (L2) nematodes are loaded in C. elegans Maintenance Media (CeMM) in the bioanalytical module during pre-launch assembly. By the time orbit is established, the worms have grown to sufficient density to be imaged and are fed fresh CeMM. The strains are pumped sequentially into the imaging area, imaged, then pumped into waste. Reagent storage utilizes polymer bags under slight pressure to prevent bubble formation in wells or channels. The optical system images green and red fluorescence bands by excitation with blue (473 nm peak

  19. Scanning near-field optical microscopy on rough surfaces: applications in chemistry, biology, and medicine

    Directory of Open Access Journals (Sweden)


    Full Text Available Shear-force apertureless scanning near-field optical microscopy (SNOM with very sharp uncoated tapered waveguides relies on the unexpected enhancement of reflection in the shear-force gap. It is the technique for obtaining chemical (materials contrast in the optical image of “real world” surfaces that are rough and very rough without topographical artifacts, and it is by far less complicated than other SNOM techniques that can only be used for very flat surfaces. The experimental use of the new photophysical effect is described. The applications of the new technique are manifold. Important mechanistic questions in solid-state chemistry (oxidation, diazotization, photodimerization, surface hydration, hydrolysis are answered with respect to simultaneous AFM (atomic force microscopy and detailed crystal packing. Prehistoric petrified bacteria and concomitant pyrite inclusions are also investigated with local RAMAN SNOM. Polymer beads and unstained biological objects (rabbit heart, shrimp eye allow for nanoscopic analysis of cell organelles. Similarly, human teeth and a cancerous tissue are analyzed. Bladder cancer tissue is clearly differentiated from healthy tissue without staining and this opens a new highly promising diagnostic tool for precancer diagnosis. Industrial applications are demonstrated at the corrosion behavior of dental alloys (withdrawal of a widely used alloy, harmless substitutes, improvement of paper glazing, behavior of blood bags upon storage, quality assessment of metal particle preparations for surface enhanced RAMAN spectroscopy, and determination of diffusion coefficient and light fastness in textile fiber dyeing. The latter applications include fluorescence SNOM. Local fluorescence SNOM is also used in the study of partly aggregating dye nanoparticles within resin/varnish preparations. Unexpected new insights are obtained in all of the various fields that cannot be obtained by other techniques.

  20. Edge-Preserving Regularization for the Deconvolution of Biological Images in Nanoscopy (United States)

    Sawatzky, Alex; Burger, Martin


    This paper deals with reconstructions of density images from data with Poisson statistics, with particular focus on cartoon reconstructions. We propose a total variation (TV) based regularization technique adapted to the case of Poisson data and use a forward-backward (FB) splitting strategy to create a numerical scheme that alternates a standard Expectation-Maximization (EM) reconstruction step with a TV correction step, which is realized by a modified version of the Rudin-Osher-Fatemi (ROF) model. We illustrate our technique at a synthetic object simulating optical nanoscopy measurements. Inspired by the high redundancy of information in a typical biological image, we give an outlook for an extension of the FB-EM-TV method to a nonlocal TV (NL-TV) regularization. NL-TV uses a nonlocal graph regularization, which allows to take advantage of the high degree of redundancy of natural images. Furthermore, we discuss the main challenges of the nonlocal regularization to create efficient numerical solvers which occurs automatically due to the high structure of complexity of the nonlocal regularization graph.

  1. Application of optical coherence tomography attenuation imaging for quantification of optical properties in medulloblastoma (United States)

    Vuong, Barry; Skowron, Patryk; Kiehl, Tim-Rasmus; Kyan, Matthew; Garzia, Livia; Genis, Helen; Sun, Cuiru; Taylor, Michael D.; Yang, Victor X. D.


    The hemodynamic environment is known to play a crucial role in the progression, rupture, and treatment of intracranial aneurysms. Currently there is difficulty assessing and measuring blood flow profiles in vivo. An emerging high resolution imaging modality known as split spectrum Doppler optical coherence tomography (ssDOCT) has demonstrated the capability to quantify hemodynamic patterns as well as arterial microstructural changes. In this study, we present a novel in vitro method to acquire precise blood flow patterns within a patient- specific aneurysm silicone flow models using ssDOCT imaging. Computational fluid dynamics (CFD) models were generated to verify ssDOCT results.

  2. Optical-CT imaging of complex 3D dose distributions (United States)

    Oldham, Mark; Kim, Leonard; Hugo, Geoffrey


    The limitations of conventional dosimeters restrict the comprehensiveness of verification that can be performed for advanced radiation treatments presenting an immediate and substantial problem for clinics attempting to implement these techniques. In essence, the rapid advances in the technology of radiation delivery have not been paralleled by corresponding advances in the ability to verify these treatments. Optical-CT gel-dosimetry is a relatively new technique with potential to address this imbalance by providing high resolution 3D dose maps in polymer and radiochromic gel dosimeters. We have constructed a 1st generation optical-CT scanner capable of high resolution 3D dosimetry and applied it to a number of simple and increasingly complex dose distributions including intensity-modulated-radiation-therapy (IMRT). Prior to application to IMRT, the robustness of optical-CT gel dosimetry was investigated on geometry and variable attenuation phantoms. Physical techniques and image processing methods were developed to minimize deleterious effects of refraction, reflection, and scattered laser light. Here we present results of investigations into achieving accurate high-resolution 3D dosimetry with optical-CT, and show clinical examples of 3D IMRT dosimetry verification. In conclusion, optical-CT gel dosimetry can provide high resolution 3D dose maps that greatly facilitate comprehensive verification of complex 3D radiation treatments. Good agreement was observed at high dose levels (>50%) between planned and measured dose distributions. Some systematic discrepancies were observed however (rms discrepancy 3% at high dose levels) indicating further work is required to eliminate confounding factors presently compromising the accuracy of optical-CT 3D gel-dosimetry.

  3. Cell Wall Biology: Perspectives from Cell Wall Imaging

    Institute of Scientific and Technical Information of China (English)

    Kieran J.D.Lee; Susan E.Marcus; J.Paul Knox


    Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth,are major repositories for photosynthetically accumulated carbon,and,in addition,impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose,hemicelluloses,and pectic polysaccharides. During the evolution of land plants,polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.

  4. Optical diagnostics for turbulent and multiphase flows: Particle image velocimetry and photorefractive optics

    Energy Technology Data Exchange (ETDEWEB)

    O`Hern, T.J.; Torczynski, J.R.; Shagam, R.N.; Blanchat, T.K.; Chu, T.Y.; Tassin-Leger, A.L.; Henderson, J.A.


    This report summarizes the work performed under the Sandia Laboratory Directed Research and Development (LDRD) project ``Optical Diagnostics for Turbulent and Multiphase Flows.`` Advanced optical diagnostics have been investigated and developed for flow field measurements, including capabilities for measurement in turbulent, multiphase, and heated flows. Particle Image Velocimetry (PIV) includes several techniques for measurement of instantaneous flow field velocities and associated turbulence quantities. Nonlinear photorefractive optical materials have been investigated for the possibility of measuring turbulence quantities (turbulent spectrum) more directly. The two-dimensional PIV techniques developed under this LDRD were shown to work well, and were compared with more traditional laser Doppler velocimetry (LDV). Three-dimensional PIV techniques were developed and tested, but due to several experimental difficulties were not as successful. The photorefractive techniques were tested, and both potential capabilities and possible problem areas were elucidated.

  5. Recent developments in widely tunable and high peak power ultrafast laser sources and their adoption in biological imaging (United States)

    Klein, J.


    Widely tunable ultrafast lasers have enabled a large number of biological imaging techniques including point scanning multiphoton excited fluorescence (MPEF), SHG/THG and stimulated Raman imaging. Tunable ultrafast lasers offer spectral agility, covering the entire relative transparency window in live tissue (700-1300nnm) and flexibility with multi-color, synchronized outputs to support sophisticated label free techniques (e.g. stimulated Raman modalities). More recently newly available high peak power lasers based on Ytterbium technology drive advances in two-photon light-sheet, 3 photon excited fluorescence and holographic patterning for optogenetics photo-stimulation. These laser platforms offer a unique blend of compactness, ease of use and cost efficiency, and ideally complement tunable platforms typically based on Ti:Sapphire and IR optical parametric oscillators (OPO). We present various types of ultrafast laser architectures, link their optical characteristics to key bio-imaging requirements, and present relevant examples and images illustrating their impact in biological science. In particular we review the use of ultrafast lasers in optogenetics for photo-stimulation of networks of neurons.

  6. Calibrated sky imager for aerosol optical properties determination

    Directory of Open Access Journals (Sweden)

    A. Cazorla


    Full Text Available The calibrated ground-based sky imager developed in the Marine Physical Laboratory, the Whole Sky Imager (WSI, has been tested to determine optical properties of the atmospheric aerosol. Different neural network-based models calculate the aerosol optical depth (AOD for three wavelengths using the radiance extracted from the principal plane of sky images from the WSI as input parameters. The models use data from a CIMEL CE318 photometer for training and validation and the wavelengths used correspond to the closest wavelengths in both instruments. The spectral dependency of the AOD, characterized by the Ångström exponent α in the interval 440–870, is also derived using the standard AERONET procedure and also with a neural network-based model using the values obtained with a CIMEL CE318. The deviations between the WSI derived AOD and the AOD retrieved by AERONET are within the nominal uncertainty assigned to the AERONET AOD calculation (±0.01, in 80% of the cases. The explanation of data variance by the model is over 92% in all cases. In the case of α, the deviation is within the uncertainty assigned to the AERONET α (±0.1 in 50% for the standard method and 84% for the neural network-based model. The explanation of data variance by the model is 63% for the standard method and 77% for the neural network-based model.

  7. Toward 5D image reconstruction for optical interferometry (United States)

    Baron, Fabien; Kloppenborg, Brian; Monnier, John


    We report on our progress toward a flexible image reconstruction software for optical interferometry capable of "5D imaging" of stellar surfaces. 5D imaging is here defined as the capability to image directly one or several stars in three dimensions, with both the time and wavelength dependencies taken into account during the reconstruction process. Our algorithm makes use of the Healpix (Gorski et al., 2005) sphere partition scheme to tesselate the stellar surface, 3D Open Graphics Language (OpenGL) to model the spheroid geometry, and the Open Compute Language (OpenCL) framework for all other computations. We use the Monte Carlo Markov Chain software SQUEEZE to solve the image reconstruction problem on the surfaces of these stars. Finally, the Compressed Sensing and Bayesian Evidence paradigms are employed to determine the best regularization for spotted stars. Our algorithm makes use of the Healpix (reference needed) sphere partition scheme to tesselate the stellar surface, 3D Open Graphics Language (OpenGL) to model the spheroid, and the Open Compute Language (OpenCL) framework to model the Roche gravitational potential equation.

  8. Multimode optical imaging of small animals: development and applications (United States)

    Hwang, J. Y.; Moffatt-Blue, C.; Equils, O.; Fujita, M.; Jeong, J.; Khazenzon, N. M.; Lindsley, E.; Ljubimova, J.; Nowatzyk, A. G.; Farkas, D. L.; Wachsmann-Hogiu, S.


    We present an optical system for small animal imaging that can combine various in vivo imaging modalities, including fluorescence (intensity and lifetime), spectral, and trans-illumination imaging. This system consists of light-tight box with ultrafast pulsed or cw laser light excitation, motorized translational and rotational stages, a telecentric lens for detection, and a cooled CCD camera that can be coupled to an ultrafast time-gated intensifier. All components are modular, making possible laser excitation at various wavelengths and pulse lengths, and signal detection in a variety of ways (multimode). Results of drug nanoconjugate carrier delivery studies in mice are presented. Conventional and spectrally-resolved fluorescence images reveal details of in vivo drug nanoconjugate carrier accumulation within the tumor region and several organs in real time. By multi-spectral image analysis of ex vivo specimens from the same mice, we were able to evaluate the extent and topology of drug nanoconjugate carrier distribution into specific organs and the tumor itself.

  9. Advanced magneto-optical microscopy: Imaging from picoseconds to centimeters - imaging spin waves and temperature distributions (invited

    Directory of Open Access Journals (Sweden)

    Necdet Onur Urs


    Full Text Available Recent developments in the observation of magnetic domains and domain walls by wide-field optical microscopy based on the magneto-optical Kerr, Faraday, Voigt, and Gradient effect are reviewed. Emphasis is given to the existence of higher order magneto-optical effects for advanced magnetic imaging. Fundamental concepts and advances in methodology are discussed that allow for imaging of magnetic domains on various length and time scales. Time-resolved imaging of electric field induced domain wall rotation is shown. Visualization of magnetization dynamics down to picosecond temporal resolution for the imaging of spin-waves and magneto-optical multi-effect domain imaging techniques for obtaining vectorial information are demonstrated. Beyond conventional domain imaging, the use of a magneto-optical indicator technique for local temperature sensing is shown.

  10. Imaging cutaneous T-Cell lymphoma with optical coherence tomography

    DEFF Research Database (Denmark)

    Ring, H.C.; Hansen Stamp, I.M.; Jemec, G.B.E.


    Aim: To investigate the presentation of a patch-stage cutaneous T-cell lymphoma (CTCL) using optical coherence tomography (OCT). Methods: A patient with a patch caused by CTCL was photographed digitally, OCT-scanned and biopsied. A normal skin area adjacent to the patch was OCT-scanned for compar......Aim: To investigate the presentation of a patch-stage cutaneous T-cell lymphoma (CTCL) using optical coherence tomography (OCT). Methods: A patient with a patch caused by CTCL was photographed digitally, OCT-scanned and biopsied. A normal skin area adjacent to the patch was OCT.......13 mm. A good immediate correlation was found between histology and OCT imaging of the sample. Conclusion: The aetiology of the elongated structures is thought to be lymphomatous infiltrates. Similar findings have been described in ocular lymphoma and may therefore be an important characteristic...

  11. Nonlinear optical imaging of defects in cubic silicon carbide epilayers. (United States)

    Hristu, Radu; Stanciu, Stefan G; Tranca, Denis E; Matei, Alecs; Stanciu, George A


    Silicon carbide is one of the most promising materials for power electronic devices capable of operating at extreme conditions. The widespread application of silicon carbide power devices is however limited by the presence of structural defects in silicon carbide epilayers. Our experiment demonstrates that optical second harmonic generation imaging represents a viable solution for characterizing structural defects such as stacking faults, dislocations and double positioning boundaries in cubic silicon carbide layers. X-ray diffraction and optical second harmonic rotational anisotropy were used to confirm the growth of the cubic polytype, atomic force microscopy was used to support the identification of silicon carbide defects based on their distinct shape, while second harmonic generation microscopy revealed the detailed structure of the defects. Our results show that this fast and noninvasive investigation method can identify defects which appear during the crystal growth and can be used to certify areas within the silicon carbide epilayer that have optimal quality.

  12. EUV optical system for the reticle imaging microscope (RIM) (United States)

    Glatzel, H.; Daniel, J.; Khajehnouri, K.; Mueller, U.; Roff, T.; Rosenbohm, J.; Sporer, S.


    The EUV optical system of the Reticle Imaging Microscope (RIM) for EUV mask inspection consists of a pinched Xeplasma source, a pupil-relayed Koehler-type illumination system and an equal-radii Cassegrain-type microscope with a 10x magnification1. The 3D surface topologies were characterized over spatial wavelengths ranging from the clear apertures down to a few nanometers by using a portfolio of instruments including contacting profilometry, phase-shifting interferometry at 633 nm at various magnifications and Atomic Force Microscopy. Measured 3D topography maps were Fourier analyzed and Power Spectral Densities (PSDs) are computed over spatial periods ranging from the critical aperture down to a few nm. Integrated RMS surface errors over typically reported spatial period ranges were computed. For a different optical system we improved our polishing process to reduce surface errors for spatial periods below 10 mm. PSDs and integrated RMS surface errors will be shown in comparison with typical RIM surfaces. All surfaces of the RIM optical system were coated with high-reflectivity coatings to maximize optical throughput. A description of the coatings and their performance had been published recently by Michael Kriese et al.2 The transmitted wavefront error (TWF) of the imager module was measured in a double pass configuration using a Fizeau-type Interferometer at 633 nm wavelength and a convex retrosphere. The measured TWF will be shown over the entire Numerical Aperture (NA = 0.0625) of the microscope. The integrated RMS of the TWF measured 0.79 nm.

  13. Nonlinear optical imaging and Raman microspectrometry of the cell nucleus throughout the cell cycle. (United States)

    Pliss, Artem; Kuzmin, Andrey N; Kachynski, Aliaksandr V; Prasad, Paras N


    Fundamental understanding of cellular processes at molecular level is of considerable importance in cell biology as well as in biomedical disciplines for early diagnosis of infection and cancer diseases, and for developing new molecular medicine-based therapies. Modern biophotonics offers exclusive capabilities to obtain information on molecular composition, organization, and dynamics in a cell by utilizing a combination of optical spectroscopy and optical imaging. We introduce here a combination of Raman microspectrometry, together with coherent anti-Stokes Raman scattering (CARS) and two-photon excited fluorescence (TPEF) nonlinear optical microscopy, to study macromolecular organization of the nucleus throughout the cell cycle. Site-specific concentrations of proteins, DNA, RNA, and lipids were determined in nucleoli, nucleoplasmic transcription sites, nuclear speckles, constitutive heterochromatin domains, mitotic chromosomes, and extrachromosomal regions of mitotic cells by quantitative confocal Raman microspectrometry. A surprising finding, obtained in our study, is that the local concentration of proteins does not increase during DNA compaction. We also demonstrate that postmitotic DNA decondensation is a gradual process, continuing for several hours. The quantitative Raman spectroscopic analysis was corroborated with CARS/TPEF multimodal imaging to visualize the distribution of protein, DNA, RNA, and lipid macromolecules throughout the cell cycle.

  14. Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography (United States)

    Peña, Adrián F.; Doronin, Alexander; Tuchin, Valery V.; Meglinski, Igor


    The influence of a low-frequency electric field applied to soft biological tissues ex vivo at normal conditions and upon the topical application of optical clearing agents has been studied by optical coherence tomography (OCT). The electro-kinetic response of tissues has been observed and quantitatively evaluated by the double correlation OCT approach, utilizing consistent application of an adaptive Wiener filtering and Fourier domain correlation algorithm. The results show that fluctuations, induced by the electric field within the biological tissues are exponentially increased in time. We demonstrate that in comparison to impedance measurements and the mapping of the temperature profile at the surface of the tissue samples, the double correlation OCT approach is much more sensitive to the changes associated with the tissues' electro-kinetic response. We also found that topical application of the optical clearing agent reduces the tissues' electro-kinetic response and is cooling the tissue, thus reducing the temperature induced by the electric current by a few degrees. We anticipate that dcOCT approach can find a new application in bioelectrical impedance analysis and monitoring of the electric properties of biological tissues, including the resistivity of high water content tissues and its variations.

  15. Laparoscopic optical coherence tomographic imaging of human ovarian cancer (United States)

    Hariri, Lida P.; Bonnema, Garret T.; Schmidt, Kathy; Korde, Vrushali; Winkler, Amy M.; Hatch, Kenneth; Brewer, Molly; Barton, Jennifer K.


    Ovarian cancer is the fourth leading cause of cancer-related death among women. If diagnosed at early stages, 5-year survival rate is 94%, but drops to 68% for regional disease and 29% for distant metastasis; only 19% of cases are diagnosed at early, localized stages. Optical coherence tomography is a recently emerging non-destructive imaging technology, achieving high axial resolutions (10-20 µm) at imaging depths up to 2 mm. Previously, we studied OCT in normal and diseased human ovary ex vivo. Changes in collagen were suggested with several images that correlated with changes in collagen seen in malignancy. Areas of necrosis and blood vessels were also visualized using OCT, indicative of an underlying tissue abnormality. We recently developed a custom side-firing laparoscopic OCT (LOCT) probe fabricated for in vivo imaging. The LOCT probe, consisting of a 38 mm diameter handpiece terminated in a 280 mm long, 4.6 mm diameter tip for insertion into the laparoscopic trocar, is capable of obtaining up to 9.5 mm image lengths at 10 µm axial resolution. In this pilot study, we utilize the LOCT probe to image one or both ovaries of 17 patients undergoing laparotomy or transabdominal endoscopy and oophorectomy to determine if OCT is capable of differentiating normal and neoplastic ovary. We have laparoscopically imaged the ovaries of seventeen patients with no known complications. Initial data evaluation reveals qualitative distinguishability between the features of undiseased post-menopausal ovary and the cystic, non-homogenous appearance of neoplastic ovary such as serous cystadenoma and endometroid adenocarcinoma.

  16. Cloud Detection of Optical Satellite Images Using Support Vector Machine (United States)

    Lee, Kuan-Yi; Lin, Chao-Hung


    Cloud covers are generally present in optical remote-sensing images, which limit the usage of acquired images and increase the difficulty of data analysis, such as image compositing, correction of atmosphere effects, calculations of vegetation induces, land cover classification, and land cover change detection. In previous studies, thresholding is a common and useful method in cloud detection. However, a selected threshold is usually suitable for certain cases or local study areas, and it may be failed in other cases. In other words, thresholding-based methods are data-sensitive. Besides, there are many exceptions to control, and the environment is changed dynamically. Using the same threshold value on various data is not effective. In this study, a threshold-free method based on Support Vector Machine (SVM) is proposed, which can avoid the abovementioned problems. A statistical model is adopted to detect clouds instead of a subjective thresholding-based method, which is the main idea of this study. The features used in a classifier is the key to a successful classification. As a result, Automatic Cloud Cover Assessment (ACCA) algorithm, which is based on physical characteristics of clouds, is used to distinguish the clouds and other objects. In the same way, the algorithm called Fmask (Zhu et al., 2012) uses a lot of thresholds and criteria to screen clouds, cloud shadows, and snow. Therefore, the algorithm of feature extraction is based on the ACCA algorithm and Fmask. Spatial and temporal information are also important for satellite images. Consequently, co-occurrence matrix and temporal variance with uniformity of the major principal axis are used in proposed method. We aim to classify images into three groups: cloud, non-cloud and the others. In experiments, images acquired by the Landsat 7 Enhanced Thematic Mapper Plus (ETM+) and images containing the landscapes of agriculture, snow area, and island are tested. Experiment results demonstrate the detection

  17. Optical coherence tomography imaging of ocular and periocular tumours (United States)

    Medina, Carlos A; Plesec, Thomas; Singh, Arun D


    Optical coherence tomography (OCT) has become pivotal in the practice of ophthalmology. Similar to other ophthalmic subspecialties, ophthalmic oncology has also incorporated OCT into practice. Anterior segment OCT (AS-OCT), ultra-high resolution OCT (UHR-OCT), spectral domain OCT (SD-OCT) and enhanced depth imaging OCT (EDI-OCT), have all been described to be helpful in the diagnosis, treatment planning and monitoring response of ocular and periocular tumours. Herein we discuss the role of OCT including the advantages and limitations of its use in the setting of common intraocular and adnexal tumours. PMID:24599420

  18. Adaptive optics microscopy enhances image quality in deep layers of CLARITY processed brains of YFP-H mice (United States)

    Reinig, Marc R.; Novack, Samuel W.; Tao, Xiaodong; Ermini, Florian; Bentolila, Laurent A.; Roberts, Dustin G.; MacKenzie-Graham, Allan; Godshalk, S. E.; Raven, M. A.; Kubby, Joel


    Optical sectioning of biological tissues has become the method of choice for three-dimensional histological analyses. This is particularly important in the brain were neurons can extend processes over large distances and often whole brain tracing of neuronal processes is desirable. To allow deeper optical penetration, which in fixed tissue is limited by scattering and refractive index mismatching, tissue-clearing procedures such as CLARITY have been developed. CLARITY processed brains have a nearly uniform refractive index and three-dimensional reconstructions at cellular resolution have been published. However, when imaging in deep layers at submicron resolution some limitations caused by residual refractive index mismatching become apparent, as the resulting wavefront aberrations distort the microscopic image. The wavefront can be corrected with adaptive optics. Here, we investigate the wavefront aberrations at different depths in CLARITY processed mouse brains and demonstrate the potential of adaptive optics to enable higher resolution and a better signal-to-noise ratio. Our adaptive optics system achieves high-speed measurement and correction of the wavefront with an open-loop control using a wave front sensor and a deformable mirror. Using adaptive optics enhanced microscopy, we demonstrate improved image quality wavefront, point spread function, and signal to noise in the cortex of YFP-H mice.

  19. Pre-Juno Optical Analysis of Jupiter's Atmosphere with the NMSU Acousto-optic Imaging Camera (United States)

    Dahl, Emma; Chanover, Nancy J.; Voelz, David; Kuehn, David M.; Strycker, Paul D.


    Jupiter's upper atmosphere is a highly dynamic system in which clouds and storms change color, shape, and size on variable timescales. The exact mechanism by which the deep atmosphere affects these changes in the uppermost cloud deck is still unknown. With Juno's arrival at Jupiter in July 2016, the thermal radiation from the deep atmosphere will be measurable with the spacecraft's Microwave Radiometer. By taking detailed optical measurements of Jupiter's uppermost cloud deck in conjunction with Juno's microwave observations, we can provide a context in which to better understand these observations. This data will also provide a complement to the near-IR sensitivity of the Jovian InfraRed Auroral Mapper and will expand on the limited spectral coverage of JunoCam. Ultimately, we can utilize the two complementary datasets in order to thoroughly characterize Jupiter's atmosphere in terms of its vertical cloud structure, color distribution, and dynamical state throughout the Juno era. In order to obtain high spectral resolution images of Jupiter's atmosphere in the optical regime, we use the New Mexico State University Acousto-optic Imaging Camera (NAIC). NAIC contains an acousto-optic tunable filter, which allows us to take hyperspectral image cubes of Jupiter from 450-950 nm at an average spectral resolution (λ/dλ) of 242. We present an analysis of our pre-Juno dataset obtained with NAIC at the Apache Point Observatory 3.5-m telescope during the night of March 28, 2016. Under primarily photometric conditions, we obtained 6 hyperspectral image cubes of Jupiter over the course of the night, totaling approximately 2,960 images. From these data we derive low-resolution optical spectra of the Great Red Spot and a representative belt and zone to compare with previous work and laboratory measurements of candidate chromophore materials. Future work will focus on radiative transfer modeling to elucidate the Jovian cloud structure during the Juno era. This work was supported

  20. Study on the MWIR imaging ability of optical readout bimaterial microcantilever FPA uncooled infrared imaging system (United States)

    Zhou, Bingbing; Feng, Yun; Zhao, Yuejin; Dong, Liquan; Liu, Ming; Chu, Xuhong; Yu, Xiaomei


    In this paper, we analyze and experimentally demonstrate the medium-wave infrared (MWIR) imaging ability based on optical readout bimaterial microcantilever focal plane array (FPA) uncooled infrared imaging system. Multiband infrared imaging technology has been a hotspot in the field of infrared imaging. In the infrared band, medium-wave infrared (3 5 μm) has minimal attenuation of atmospheric infrared window, and it also covers many atomic and molecular absorption peak. Imaging study on MWIR radiation source also appears particularly important. First of all, we introduce the bimaterial microcantilever IR sensing principle and the fabrication of the bimaterial microcantilever FPA. Secondly, the paper introduces the theory of the optical-thermal-mechnical reading based on FPA. Finally, the experimental platform was constructed to conduct the MWIR imaging experiment. The medium-wave infrared radiation source consists of a continuous-wave optical parametric oscillator (OPO) that is pumped by a polarization-maintained, single-mode fiber amplifier. The length of the 50mm periodically polarized LiNbO3 crystal (5%MgO) is used as the nonlinear crystal. The stable cavity of the ring is designed, and the output of the 3 4 μm band is realized by the design of the nonlinear crystal polarization period. And the FPA employed in our experiment contains 256×256 pixels fabricated on a glass substrate, whose working bandwidth is covering the three IR atmospheric windows. The experimental results show that the bimaterial microcantilever FPA has a good imaging ability to the MWIR sources.

  1. Evaluation of Pyro-optic Materials for Infrared Imaging (United States)

    Pandey, R. K.; Kotru, Sushma; Song, Xiuyu; Donnelly, David


    Infrared detectors are needed for a wide range of applications. IR detectors operate either on the principles of photon detection or pyroelectric detection. Both these systems have their respective advantages and disadvantages. However, both of them inherently have difficulties in management of noise to signal ratio and in read-out circuitory. One of the most serious handicaps of photon detectors is requirement of cryogenic cooling for satisfactory operation. In this respect uncooled pyroelectric detectors operating at above room temperature have an advantage. An alternative to these approaches can be pyro-optic based detectors. Only a handful of materials have been found with some satisfactory level of pyro-optic coefficients appropriate for imaginig devices. Some of them are: antimony-sulfo-iodide (SbSI), molybdenum sulfide (MoS2), bismuth vanadate (BiVO4) and Pb-based titanates. Pyrooptic coefficients of these materials have been reported using presumably bulk single crystals. However, no such data are available for their thin films which would be very important for light weight integrated structured devices.In this paper we will describe the parameters and optimization protocol for the growh of thin films of these materials on thermally insulating substrates. We will also discuss their structural, electrical and optical properties. Our investigations suggest that SbSI, BiVO4 and PNZT films are attractive options for advancing the IR detecting technology by utilizing the pyro-optic effect. Integrated thin film structures might lead to the fabrication of light weight, low cost, noise immune and efficient imaging devices based on pyro-optic properties. This research is sponsored by the DEPSCoR program of the U.S. Army Research Office.

  2. MICADO: the E-ELT Adaptive Optics Imaging Camera

    CERN Document Server

    Davies, R


    MICADO is the adaptive optics imaging camera for the E-ELT. It has been designed and optimised to be mounted to the LGS-MCAO system MAORY, and will provide diffraction limited imaging over a wide (about 1 arcmin) field of view. For initial operations, it can also be used with its own simpler AO module that provides on-axis diffraction limited performance using natural guide stars. We discuss the instrument's key capabilities and expected performance, and show how the science drivers have shaped its design. We outline the technical concept, from the opto-mechanical design to operations and data processing. We describe the AO module, summarise the instrument performance, and indicate some possible future developments.

  3. Optical design of MWIR imaging spectrometer with a cold slit (United States)

    Zhou, Shiyao; Wang, Yueming; Qian, Liqun; Yuan, Liyin; Wang, Jianyu


    MWIR imaging spectrometer is promising in detecting spectral signature of high temperature object such as jet steam, guided missile and explosive gas. This paper introduces an optical design of a MWIR imaging spectrometer with a cold slit sharply reducing the stray radiation from exterior environment and interior structure. The spectrometer is composed of a slit, a spherical prism as disperser, two concentric spheres and a correction lens. It has a real entrance pupil to match the objective and for setting the infrared cold shield near the slit and a real exit pupil to match the cold shield of the focal plane array (FPA). There are two cooled parts, one includes the aperture stop and slit, and the other is the exit pupil and the FPA with two specially positioned cooled shields. A detailed stray radiation analysis is represented which demonstrates the outstanding effect of this system in background radiation restraint.

  4. Optimized optical clearing method for imaging central nervous system (United States)

    Yu, Tingting; Qi, Yisong; Gong, Hui; Luo, Qingming; Zhu, Dan


    The development of various optical clearing methods provides a great potential for imaging entire central nervous system by combining with multiple-labelling and microscopic imaging techniques. These methods had made certain clearing contributions with respective weaknesses, including tissue deformation, fluorescence quenching, execution complexity and antibody penetration limitation that makes immunostaining of tissue blocks difficult. The passive clarity technique (PACT) bypasses those problems and clears the samples with simple implementation, excellent transparency with fine fluorescence retention, but the passive tissue clearing method needs too long time. In this study, we not only accelerate the clearing speed of brain blocks but also preserve GFP fluorescence well by screening an optimal clearing temperature. The selection of proper temperature will make PACT more applicable, which evidently broaden the application range of this method.

  5. Resonant Doppler imaging with Fourier domain optical coherence tomography (United States)

    Leitgeb, Rainer A.; Szklumowska, Anna; Pircher, Michael; Gotzinger, Erich; Fercher, Adolf F.


    Fourier Domain Optical Coherene Tomography (FD OCT) is a high speed imaging modality with increased sensitivity as compared to standard time domain (TD) OCT. The higher sensitivity is especially important, if strongly scattering tissue such as blood is investigated. Recently it could be shown that retinal blood flow can be assessed in-vivo by high speed FD OCT. However the detection bandwidth of color Doppler (CD) FDOCT is strongly limited due to blurring of the detected interference fringes during exposure. This leads to a loss of sensitivity for detection of fast changes in tissue. Using a moving mirror as a reference one can effectively increase the detection bandwidth for CD FDOCT and perform perfusion sectioning. The modality is called resonant CD FDOCT imaging. The principle of the method is presented and experimentally verified.

  6. Real-time digital signal processing for live electro-optic imaging. (United States)

    Sasagawa, Kiyotaka; Kanno, Atsushi; Tsuchiya, Masahiro


    We present an imaging system that enables real-time magnitude and phase detection of modulated signals and its application to a Live Electro-optic Imaging (LEI) system, which realizes instantaneous visualization of RF electric fields. The real-time acquisition of magnitude and phase images of a modulated optical signal at 5 kHz is demonstrated by imaging with a Si-based high-speed CMOS image sensor and real-time signal processing with a digital signal processor. In the LEI system, RF electric fields are probed with light via an electro-optic crystal plate and downconverted to an intermediate frequency by parallel optical heterodyning, which can be detected with the image sensor. The artifacts caused by the optics and the image sensor characteristics are corrected by image processing. As examples, we demonstrate real-time visualization of electric fields from RF circuits.

  7. Methods and means of Stokes-polarimetry microscopy of optically anisotropic biological layers (United States)

    Ushenko, A. G.; Dubolazov, A. V.; Ushenko, V. A.; Ushenko, Yu. A.; Sakhnovskiy, M. Yu.; Sidor, M.; Prydiy, O. G.; Olar, O. I.; Lakusta, I. I.


    The results of optical modeling of biological tissues polycrystalline multilayer networks have been presented. Algorithms of reconstruction of parameter distributions were determined that describe the linear and circular birefringence. For the separation of the manifestations of these mechanisms we propose a method of space-frequency filtering. Criteria for differentiation of benign and malignant tissues of the women reproductive sphere were found.

  8. OPTICAL COMPUTING: Analysis of the tomographic contrast during the immersion bleaching of layered biological tissues (United States)

    Prokhorov, I. V.; Yarovenko, I. P.


    The control of optical properties of biological tissues irradiated by a cw laser source is considered. Within the framework of the stationary model of the radiation transfer, basic factors affecting the tomographic contrast of a layered medium are revealed theoretically and numerically, when immersion liquids, decreasing the radiation scattering level in a medium, are used.

  9. 3D reconstruction of SEM images by use of optical photogrammetry software. (United States)

    Eulitz, Mona; Reiss, Gebhard


    Reconstruction of the three-dimensional (3D) surface of an object to be examined is widely used for structure analysis in science and many biological questions require information about their true 3D structure. For Scanning Electron Microscopy (SEM) there has been no efficient non-destructive solution for reconstruction of the surface morphology to date. The well-known method of recording stereo pair images generates a 3D stereoscope reconstruction of a section, but not of the complete sample surface. We present a simple and non-destructive method of 3D surface reconstruction from SEM samples based on the principles of optical close range photogrammetry. In optical close range photogrammetry a series of overlapping photos is used to generate a 3D model of the surface of an object. We adapted this method to the special SEM requirements. Instead of moving a detector around the object, the object itself was rotated. A series of overlapping photos was stitched and converted into a 3D model using the software commonly used for optical photogrammetry. A rabbit kidney glomerulus was used to demonstrate the workflow of this adaption. The reconstruction produced a realistic and high-resolution 3D mesh model of the glomerular surface. The study showed that SEM micrographs are suitable for 3D reconstruction by optical photogrammetry. This new approach is a simple and useful method of 3D surface reconstruction and suitable for various applications in research and teaching.

  10. Microball lens integrated fiber probe for optical frequency domain imaging

    Institute of Scientific and Technical Information of China (English)

    Jae-Ho Han; J.U.Kang


    An integrated microball lens fiber catheter probe is demonstrated, which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical coherence tomography (FDOCT). Simulation results are shown to gain the effect of the distance between the microball lens and the bare fiber to the focusing plane and beam width. The freedom of modifying the working distance and lateral resolution is shown. This is achieved by changing the gap distance between the single-mode fiber and the microball lens within the packaged surgical needle catheter without using an additional beam expander having a fixed length. The probe successfully acquired cross-sectional images of ocular tissues from an animal sample with the proposed miniaturized imaging probe.%@@ An integrated microball lens fiber catheter probe is demonstrated,which has better lateral resolution and longer working distance than a corresponding bare fiber probe with diverging beam for Fourier domain optical coherence tomography(FDOCT).Simulation results are shown to gain the effect of the distance between the microball lens and the bare fiber to the focusing plane and beam width.The freedom of modifying the working distance and lateral resolution is shown.This is achieved by changing the gap distance between the single-mode fiber and the microball lens within the packaged surgical needle catheter without using an additional beam expander having a fixed length.The probe successfully acquired crosssectional images of ocular tissues from an animal sample with the proposed miniaturized imaging probe.

  11. The application of optical coherence tomography to image subsurface tissue structure of Antarctic krill Euphausia superba.

    Directory of Open Access Journals (Sweden)

    Nicola Bellini

    Full Text Available Many small open ocean animals, such as Antarctic krill, are an important part of marine ecosystems. To discover what will happen to animals such as krill in a changing ocean, experiments are run in aquaria where conditions can be controlled to simulate water characteristics predicted to occur in the future. The response of individual animals to changing water conditions can be hard to observe, and with current observation techniques it is very difficult to follow the progress of an individual animal through its life. Optical coherence tomography (OCT is an optical imaging technique that allows images at high resolution to be obtained from depths up to a few millimeters inside biological specimens. It is compatible with in vivo imaging and can be used repeatedly on the same specimens. In this work, we show how OCT may be applied to post mortem krill samples and how important physiological data such as shell thickness and estimates of organ volume can be obtained. Using OCT we find an average value for the thickness of krill exoskeleton to be (30±4 µm along a 1 cm length of the animal body. We also show that the technique may be used to provide detailed imagery of the internal structure of a pleopod joint and provide an estimate for the heart volume of (0.73±0.03 mm3.

  12. Contrast-enhanced optical coherence tomography with picomolar sensitivity for functional in vivo imaging (United States)

    Liba, Orly; Sorelle, Elliott D.; Sen, Debasish; de La Zerda, Adam


    Optical Coherence Tomography (OCT) enables real-time imaging of living tissues at cell-scale resolution over millimeters in three dimensions. Despite these advantages, functional biological studies with OCT have been limited by a lack of exogenous contrast agents that can be distinguished from tissue. Here we report an approach to functional OCT imaging that implements custom algorithms to spectrally identify unique contrast agents: large gold nanorods (LGNRs). LGNRs exhibit 110-fold greater spectral signal per particle than conventional GNRs, which enables detection of individual LGNRs in water and concentrations as low as 250 pM in the circulation of living mice. This translates to ~40 particles per imaging voxel in vivo. Unlike previous implementations of OCT spectral detection, the methods described herein adaptively compensate for depth and processing artifacts on a per sample basis. Collectively, these methods enable high-quality noninvasive contrast-enhanced imaging of OCT in living subjects, including detection of tumor microvasculature at twice the depth achievable with conventional OCT. Additionally, multiplexed detection of spectrally-distinct LGNRs was demonstrated to observe discrete patterns of lymphatic drainage and identify individual lymphangions and lymphatic valve functional states. These capabilities provide a powerful platform for molecular imaging and characterization of tissue noninvasively at cellular resolution, called MOZART.

  13. A Complete Bank of Optical Images of the ICRF QSOs (United States)

    Humberto Andrei, Alexandre; Taris, Francois; Anton, Sonia; Bourda, Geraldine; Damljanovic, Goran; Souchay, Jean; Vieira Martins, Roberto; Pursimo, Tapio; Barache, Christophe; Nepomuceno da Silva Neto, Dario; Fernandes Coelho, Bruno David


    We have been developing a systematic effort to collect good quality images of the optical counterpart of ICRF sources, in particular for those that have been regularly radio surveyed either for future implementation at high frequencies and/or those that will be the link sources between the ICRF and the Gaia CRF. Observations have been taken at the LNA/Brazil, CASLEO/Argentina, NOT/Spain, LFOA/Austria, Rozhen/Bulgária, and ASV/Serbia. In complement images were collected from the SDSS. As a step to implement such image data bank and make it publicly available through the IERS service we present its description, that comprises for each source the number of measurements, filter, pixel scale, size of field, and seeing at each observation. The photometry analysis is centered on the morphology, since there remain still cases in which the host galaxy is overwhelming, and many cases in which the host asks for a non-stellar PSF modeling. On basis of the neighbor stars we assign magnitudes and variability whenever possible. Finally, assisted by previous literature, the redshift and luminosity are used to derive astrophysical quantities, in special the absolute magnitude, SED and spectral index. Moreover, since Gaia will not obtain direct images of the observed sources, the morphology and magnitude becomes useful as templates onto which assembling and interpreting the one-dimensional and uncontinuous line spread function samplings that will be delivered by Gaia for each QSO.

  14. Mammographic quantitative image analysis and biologic image composition for breast lesion characterization and classification

    Energy Technology Data Exchange (ETDEWEB)

    Drukker, Karen, E-mail:; Giger, Maryellen L.; Li, Hui [Department of Radiology, University of Chicago, Chicago, Illinois 60637 (United States); Duewer, Fred; Malkov, Serghei; Joe, Bonnie; Kerlikowske, Karla; Shepherd, John A. [Radiology Department, University of California, San Francisco, California 94143 (United States); Flowers, Chris I. [Department of Radiology, University of South Florida, Tampa, Florida 33612 (United States); Drukteinis, Jennifer S. [Department of Radiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612 (United States)


    Purpose: To investigate whether biologic image composition of mammographic lesions can improve upon existing mammographic quantitative image analysis (QIA) in estimating the probability of malignancy. Methods: The study population consisted of 45 breast lesions imaged with dual-energy mammography prior to breast biopsy with final diagnosis resulting in 10 invasive ductal carcinomas, 5 ductal carcinomain situ, 11 fibroadenomas, and 19 other benign diagnoses. Analysis was threefold: (1) The raw low-energy mammographic images were analyzed with an established in-house QIA method, “QIA alone,” (2) the three-compartment breast (3CB) composition measure—derived from the dual-energy mammography—of water, lipid, and protein thickness were assessed, “3CB alone”, and (3) information from QIA and 3CB was combined, “QIA + 3CB.” Analysis was initiated from radiologist-indicated lesion centers and was otherwise fully automated. Steps of the QIA and 3CB methods were lesion segmentation, characterization, and subsequent classification for malignancy in leave-one-case-out cross-validation. Performance assessment included box plots, Bland–Altman plots, and Receiver Operating Characteristic (ROC) analysis. Results: The area under the ROC curve (AUC) for distinguishing between benign and malignant lesions (invasive and DCIS) was 0.81 (standard error 0.07) for the “QIA alone” method, 0.72 (0.07) for “3CB alone” method, and 0.86 (0.04) for “QIA+3CB” combined. The difference in AUC was 0.043 between “QIA + 3CB” and “QIA alone” but failed to reach statistical significance (95% confidence interval [–0.17 to + 0.26]). Conclusions: In this pilot study analyzing the new 3CB imaging modality, knowledge of the composition of breast lesions and their periphery appeared additive in combination with existing mammographic QIA methods for the distinction between different benign and malignant lesion types.

  15. Blurred and noisy image pairs in parallel optics. (United States)

    Klapp, Iftach; Sochen, Nir; Mendlovic, David


    In previous works we have shown that parallel optics (PO) architecture can be used to improve the system matrix condition, which results in improving its immunity to additive noise in the image restoration process. PO is composed of a "main" system and an "auxiliary" system. Previously, we suggested the "trajectories" method to realize PO. In that method, a required auxiliary system is composed from auxiliary optics with a pixel confined response, followed by signal processing. In this paper, we emphasize the important secondary effects of the trajectories method. We show that in such a system, where the postprocessing comes after the detection, the postprocessing acts as a noise filter, hence allowing us to work with noisy data in the auxiliary channel. Roughly speaking, the SNR of an imaging system depends on the numerical aperture (NA). It follows that the main system, which typically has a higher NA, also has a higher SNR. Hence in the PO system, the ratio between the NA values of the main and auxiliary systems is expected to dictate the gap between their SNR values. In this paper, we show that when the system is implemented by the trajectories method, this expectation is too conservative. It is shown that due to the noise filtering, the auxiliary system can be noisier than expected. This claim is proved analytically and verified and exemplified by using experimental measurements.

  16. From acoustic segmentation to language processing: evidence from optical imaging. (United States)

    Obrig, Hellmuth; Rossi, Sonja; Telkemeyer, Silke; Wartenburger, Isabell


    During language acquisition in infancy and when learning a foreign language, the segmentation of the auditory stream into words and phrases is a complex process. Intuitively, learners use "anchors" to segment the acoustic speech stream into meaningful units like words and phrases. Regularities on a segmental (e.g., phonological) or suprasegmental (e.g., prosodic) level can provide such anchors. Regarding the neuronal processing of these two kinds of linguistic cues a left-hemispheric dominance for segmental and a right-hemispheric bias for suprasegmental information has been reported in adults. Though lateralization is common in a number of higher cognitive functions, its prominence in language may also be a key to understanding the rapid emergence of the language network in infants and the ease at which we master our language in adulthood. One question here is whether the hemispheric lateralization is driven by linguistic input per se or whether non-linguistic, especially acoustic factors, "guide" the lateralization process. Methodologically, functional magnetic resonance imaging provides unsurpassed anatomical detail for such an enquiry. However, instrumental noise, experimental constraints and interference with EEG assessment limit its applicability, pointedly in infants and also when investigating the link between auditory and linguistic processing. Optical methods have the potential to fill this gap. Here we review a number of recent studies using optical imaging to investigate hemispheric differences during segmentation and basic auditory feature analysis in language development.

  17. Adaptive Optics and Lucky Imager (AOLI): presentation and first light

    CERN Document Server

    Velasco, S; Mackay, C; Oscoz, A; King, D L; Crass, J; Díaz-Sánchez, A; Femenía, B; González-Escalera, V; Labadie, L; López, R L; Garrido, A Pérez; Puga, M; Rodríguez-Ramos, L F; Zuther, J


    In this paper we present the Adaptive Optics Lucky Imager (AOLI), a state-of-the-art instrument which makes use of two well proved techniques for extremely high spatial resolution with ground-based telescopes: Lucky Imaging (LI) and Adaptive Optics (AO). AOLI comprises an AO system, including a low order non-linear curvature wavefront sensor together with a 241 actuators deformable mirror, a science array of four 1024x1024 EMCCDs, allowing a 120x120 down to 36x36 arcseconds field of view, a calibration subsystem and a powerful LI software. Thanks to the revolutionary WFS, AOLI shall have the capability of using faint reference stars ({\\it I\\/} $\\sim$ 16.5-17.5), enabling it to be used over a much wider part of the sky than with common Shack-Hartmann AO systems. This instrument saw first light in September 2013 at William Herschel Telescope. Although the instrument was not complete, these commissioning demonstrated its feasibility, obtaining a FWHM for the best PSF of 0.151$\\pm$0.005 arcsec and a plate scale o...

  18. Deep subwavelength nanometric image reconstruction using Fourier domain optical normalization

    Institute of Scientific and Technical Information of China (English)

    Jing Qin; Richard M Silver; Bryan M Barnes; Hui Zhou; Ronald G Dixson; Mark-Alexander Henn


    Quantitative optical measurements of deep subwavelength,three-dimensional (3D),nanometric structures with sensitivity to sub-nanometer details address a ubiquitous measurement challenge.A Fourier domain normalization approach is used in the Fourier optical imaging code to simulate the full 3D scattered light field of nominally 15 nm-sized structures,accurately replicating the light field as a function of the focus position.Using the full 3D light field,nanometer scale details such as a 2 nm thin conformal oxide and nanometer topography are rigorously fitted for features less than one-thirtiethof the wavelength in size.The densely packed structures are positioned nearly an order of magnitude closer than the conventional Rayleigh resolution limit and can be measured with sub-nanometer parametric uncertainties.This approach enables a practical measurement sensitivity to size variations of only a few atoms in size using a high-throughput optical configuration with broad application in measuring nanometric structures and nanoelectronic devices.

  19. Photoactive molecules for applications in molecular imaging and cell biology. (United States)

    Shao, Qing; Xing, Bengang


    Photoactive technology has proven successful for non-invasive regulation of biological activities and processes in living cells. With the light-directed generation of biomaterials or signals, mechanisms in cell biology can be investigated at the molecular level with spatial and temporal resolution. In this tutorial review, we aim to introduce the important applications of photoactive molecules for elucidating cell biology on aspects of protein engineering, fluorescence labelling, gene regulation and cell physiological functions.

  20. Resonant Optical Gradient Force Interaction for Nano-Imaging and-Spectroscopy (United States)


    frequency dependence of the optically induced force is often explored in optical trapping ofmicro-/ nanoparticles [5, 26–32], and in the optically...interpreted to result from an optical gradient force [38]. In contrast, similar force images on gold split ring resonators were attributed to thermal...reduced to an image sphere of radius r, as shown infigure 1(a). This coupled nanoparticle geometry has been used extensively andwith great success