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Sample records for applications reflectance confocal

  1. Design of reflectance confocal microscopes for clinical applications

    NASA Astrophysics Data System (ADS)

    Zavislan, James M.

    2009-02-01

    Reflectance confocal microscopy provides real time, cellular resolution images of in-vivo and ex-vivo tissues and has been cleared by the FDA and international regulatory agencies for medical applications. Clinical applications of reflectance confocal microscopy are being tested in single- and multi-center clinical trials. In this paper I will review the design challenges of sub-surface imaging with confocal microscopy and techniques to compare the instruments performance between different sites.

  2. Reflectance Confocal Microscopy for Inflammatory Skin Diseases.

    PubMed

    Agozzino, M; Gonzalez, S; Ardigò, M

    2016-10-01

    In vivo reflectance confocal microscopy (RCM) is a relatively novel non-invasive tool for microscopic evaluation of the skin used prevalently for diagnosis and management of skin tumour. Its axial resolution, its non-invasive and easy clinical application represents the goals for a large diffusion of this technique. During the last 15 years, RCM has been demonstrated to be able to increase the sensibility and sensitivity of dermoscopy in the diagnosis of skin tumours integrating in real time clinic, dermoscopic and microscopic information useful for the definition of malignancy. Despite to date, no large comparative studies on inflammatory skin diseases has been published in the literature, several papers already showed that RCM has a potential for the evaluation of the descriptive features of the most common inflammatory skin diseases as psoriasis, lupus erythematosus, contact dermatitis and others. The aim of the application of this technique in non-neoplastic skin diseases has been prevalently focused on the possibility of clinical diagnosis confirmation, as well as therapeutic management. Moreover, the use of RCM as driver for an optimised skin biopsy has been also followed in order to reduce the number of unsuccessful histopathological examination. In this review article we describe the confocal features of the major groups of inflammatory skin disorders focusing on psoriasiform dermatitis, interface dermatitis and spongiotic dermatitis.

  3. Reflectance Confocal Microscopy in Lentigo Maligna.

    PubMed

    Gamo, R; Pampín, A; Floristán, U

    2016-12-01

    Lentigo maligna is the most common type of facial melanoma. Diagnosis is complicated, however, as it shares clinical and dermoscopic characteristics with other cutaneous lesions of the face. Reflectance confocal microscopy is an imaging technique that permits the visualization of characteristic features of lentigo maligna. These include a disrupted honeycomb pattern and pagetoid cells with a tendency to show folliculotropism. These cells typically have a dendritic morphology, although they may also appear as round cells measuring over 20μm with atypical nuclei. Poorly defined dermal papillae and atypical cells may be seen at the dermal-epidermal junction and can form bridges resembling mitochondrial structures. Other characteristic findings include junctional swelling with atypical cells located around the follicles, resembling caput medusae. Reflectance confocal microscopy is a very useful tool for diagnosing lentigo maligna.

  4. Anal melanosis diagnosed by reflectance confocal microscopy.

    PubMed

    Cinotti, Elisa; Chol, Christelle; Perrot, Jean Luc; Labeille, Bruno; Forest, Fabien; Cambazard, Frédéric

    2014-11-01

    Until now, in vivo reflectance-mode confocal microscopy (IVCM) has been applied only to pigmented lesions of the vulvar and oral mucosa, but not to anal mucosa lesions. We present the first case in which IVCM has been used to diagnose anal melanosis. Clinical and dermoscopic features were of concern while IVCM found the draped pattern already described for genital melanosis. IVCM adds information to the clinical and dermatoscopic examination and allows skin biopsies to be avoided. Further studies are needed to define the IVCM features of anal melanosis and to compare the performance of IVCM with the findings of histological examinations.

  5. Reflectance confocal microscopy features of facial angiofibromas

    PubMed Central

    Millán-Cayetano, José-Francisco; Yélamos, Oriol; Rossi, Anthony M.; Marchetti, Michael A.; Jain, Manu

    2017-01-01

    Facial angiofibromas are benign tumors presenting as firm, dome-shaped, flesh-colored to pink papules, typically on the nose and adjoining central face. Clinically and dermoscopically they can mimic melanocytic nevi or basal cell carcinomas (BCC). Reflectance confocal microscopy (RCM) is a noninvasive imaging tool that is useful in diagnosing melanocytic and non-melanocytic facial lesions. To date no studies have described the RCM features of facial angiofibromas. Herein, we present two cases of facial angiofibromas that were imaged with RCM and revealed tumor island-like structures that mimicked BCC, leading to skin biopsy. PMID:28243496

  6. Near-infrared hyperspectral reflective confocal microscopy

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Zhang, Yunhai; Miao, Xin; Xue, Xiaojun; Xiao, Yun

    2016-10-01

    A Near-Infrared HyperSpectral Reflective Confocal Microscopy (NIHS-RCM) is proposed in order to get high resolution images of deep biological tissues such as skin. The microscopy system uses a super-continuum laser for illumination, an acousto-optic tunable filter (AOTF) for rapid selection of near-infrared spectrum, a resonant galvanometer scanner for high speed imaging (15f/s) and near-infrared avalanche diode as detector. Porcine skin and other experiments show that the microscopy system could get deep tissue images (180 μm), and show the different ingredients of tissue with different wavelength of illumination. The system has the ability of selectively imaging of multiple ingredients at deep tissue which can be used in skin diseases diagnosis and other fields.

  7. Application of reflectance confocal microscopy to evaluate skin damage after irradiation with an yttrium-scandium-gallium-garnet (YSGG) laser.

    PubMed

    Yue, Xueping; Wang, Hongwei; Li, Qing; Li, Linfeng

    2017-02-01

    The objective of this study was to observe the characteristics of the skin after irradiation with a 2790-nm yttrium-scandium-gallium-garnet (YSGG) laser using reflectance confocal microscopy (RCM). A 2790-nm YSGG laser was used to irradiate fresh foreskin (four doses, at spot density 3) in vitro. The characteristics of microscopic ablative columns (MAC), thermal coagulation zone (TCZ), and microscopic treatment zones (MTZ) were observed immediately after irradiation using digital microscope and RCM. The characteristics of MAC, TCZ, and MTZ with variations in pulse energy were comparatively analyzed. After irradiation, MAC, TCZ, and MTZ characteristics and undamaged skin between MTZs can be observed by RCM. The depth and width of MTZ obviously increased with the increase in pulse energy. At 80, 120, and 160 mJ/microbeam (MB), the MTZ actual area and proportion were about two times that of the theoretical value and three times at 200 mJ/MB. With increases in depth, the single MAC gradually decreased in a fingertip-shaped model, with TCZ slowly increasing, and MTZ slightly decreasing in a columnar shape. RCM was able to determine the characteristics of thermal injury on the skin after the 2790-nm YSGG laser irradiation with different pulse energies. Pulse energy higher than 200 mJ/MB may have much larger thermal injury and side effect. RCM could be used in the clinic in future.

  8. A handheld laser scanning confocal reflectance imaging–confocal Raman microspectroscopy system

    PubMed Central

    Patil, Chetan A.; Arrasmith, Christopher L.; Mackanos, Mark A.; Dickensheets, David L.; Mahadevan-Jansen, Anita

    2012-01-01

    Confocal reflectance microscopy and confocal Raman spectroscopy have shown potential for non-destructive analysis of samples at micron-scale resolutions. Current studies utilizing these techniques often employ large bench-top microscopes, and are not suited for use outside of laboratory settings. We have developed a microscope which combines laser scanning confocal reflectance imaging and confocal Raman spectroscopy into a compact handheld probe that is capable of high-resolution imaging and spectroscopy in a variety of settings. The compact size of the probe is largely due to the use of a MEMS mirror for beam scanning. The probe is capable of axial resolutions of up to 4 μm for the confocal imaging channel and 10 μm for the confocal Raman spectroscopy channel. Here, we report instrument design, characterize optical performance, and provide images and spectra from normal skin to demonstrate the instrument’s capabilities for clinical diagnostics. PMID:22435097

  9. Pupil engineering for a confocal reflectance line-scanning microscope

    NASA Astrophysics Data System (ADS)

    Patel, Yogesh G.; Rajadhyaksha, Milind; DiMarzio, Charles A.

    2011-03-01

    Confocal reflectance microscopy may enable screening and diagnosis of skin cancers noninvasively and in real-time, as an adjunct to biopsy and pathology. Current confocal point-scanning systems are large, complex, and expensive. A confocal line-scanning microscope, utilizing a of linear array detector can be simpler, smaller, less expensive, and may accelerate the translation of confocal microscopy in clinical and surgical dermatology. A line scanner may be implemented with a divided-pupil, half used for transmission and half for detection, or with a full-pupil using a beamsplitter. The premise is that a confocal line-scanner with either a divided-pupil or a full-pupil will provide high resolution and optical sectioning that would be competitive to that of the standard confocal point-scanner. We have developed a confocal line-scanner that combines both divided-pupil and full-pupil configurations. This combined-pupil prototype is being evaluated to determine the advantages and limitations of each configuration for imaging skin, and comparison of performance to that of commercially available standard confocal point-scanning microscopes. With the combined configuration, experimental evaluation of line spread functions (LSFs), contrast, signal-to-noise ratio, and imaging performance is in progress under identical optical and skin conditions. Experimental comparisons between divided-pupil and full-pupil LSFs will be used to determine imaging performance. Both results will be compared to theoretical calculations using our previously reported Fourier analysis model and to the confocal point spread function (PSF). These results may lead to a simpler class of confocal reflectance scanning microscopes for clinical and surgical dermatology.

  10. Spectral confocal reflection microscopy using a white light source

    NASA Astrophysics Data System (ADS)

    Booth, M.; Juškaitis, R.; Wilson, T.

    2008-08-01

    We present a reflection confocal microscope incorporating a white light supercontinuum source and spectral detection. The microscope provides images resolved spatially in three-dimensions, in addition to spectral resolution covering the wavelength range 450-650nm. Images and reflection spectra of artificial and natural specimens are presented, showing features that are not normally revealed in conventional microscopes or confocal microscopes using discrete line lasers. The specimens include thin film structures on semiconductor chips, iridescent structures in Papilio blumei butterfly scales, nacre from abalone shells and opal gemstones. Quantitative size and refractive index measurements of transparent beads are derived from spectral interference bands.

  11. FOOD SURFACE TEXTURE MEASUREMENT USING REFLECTIVE CONFOCAL LASER SCANNING MICROSCOPY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confocal laser scanning microscopy (CLSM) was used in the reflection mode to characterize the surface texture (roughness) of sliced food surfaces. Sandpapers of grit size between 150 and 600 were used as the height reference to standardize the CLSM hardware settings. Sandpaper particle sizes were v...

  12. Reflectance confocal microscopy--state-of-art and research overview.

    PubMed

    Hofmann-Wellenhof, Rainer; Wurm, Elisabeth M T; Ahlgrimm-Siess, Verena; Richtig, Erika; Koller, Silvia; Smolle, Josef; Gerger, Armin

    2009-09-01

    Reflectance confocal microscopy (RCM) enables in vivo imaging of human skin at a quasi histologic resolution. The black-and-white RCM images show horizontal sections of the skin, at a maximum depth of 350 microm. To date, the RCM features of a significant number of skin conditions have been described. The main focus of the research community investigating RCM, however, lies on describing and diagnosing melanocytic skin lesions. Taking into account all RCM studies dealing with diagnostic accuracy in melanocytic skin lesions, sensitivity and specificity of approximately 90% and 86% could be found. Improvement of diagnostic accuracy, improved assessment of dermoscopic-histologic correlation, in vivo biopsy side selection, surgical margin assessment, and response control of conservative therapies in skin diseases are some of the major advantages of this novel imaging method. Additionally, RCM holds inherent potential for teledermatologic application and automated image analyzing. This article describes morphologic features of diverse skin lesions and features of "normal skin," summarizes diagnostic advances of RCM, compares studies dealing with diagnostic applicability, and discusses further research goals of this exciting new imaging technique.

  13. Confocal reflectance imaging of excised malignant human bladder biopsies

    NASA Astrophysics Data System (ADS)

    Daniltchenko, Dmitri I.; Kastein, Albrecht; Koenig, Frank; Sachs, Markus; Schnorr, Dietmar; Al-Shukri, Salman; Loening, Stefan A.

    2004-08-01

    To evaluate the potential of reflectance confocal scanning laser microscopy (CM) for rapid imaging of non-processed freshly excised human bladder biopsies and cystectomy specimens. Freshly excised bladder tumors from three cystectomy specimens and random biopsies from twenty patients with a history of superficial bladder tumors were imaged with CM. Additional acetic acid washing prior to CM imaging was performed in some of the samples. Confocal images were compared to corresponding routine histologic sections. CM allows imaging of unprocessed bladder tissue at a subcellular resolution. Urothelial cell layers, collagen, vessels and muscle fibers can be rapidly visualized, in native state. In this regard, umbrella cells, basement membrane elucidated. Besides obvious limitations partly due to non-use of exogenous dyes, CM imaging offers several advantages: rapid imaging of the tissue in its native state like the basement membrane, normally seen only by using immunohistopathology. Reflectance CM opens a new avenue for imaging bladder cancer.

  14. Confocal Endomicroscopy: Instrumentation and Medical Applications

    PubMed Central

    Jabbour, Joey M.; Saldua, Meagan A.; Bixler, Joel N.; Maitland, Kristen C.

    2013-01-01

    Advances in fiber optic technology and miniaturized optics and mechanics have propelled confocal endomicroscopy into the clinical realm. This high resolution, non-invasive imaging technology provides the ability to microscopically evaluate cellular and sub-cellular features in tissue in vivo by optical sectioning. Because many cancers originate in epithelial tissues accessible by endoscopes, confocal endomicroscopy has been explored to detect regions of possible neoplasia at an earlier stage by imaging morphological features in vivo that are significant in histopathologic evaluation. This technique allows real-time assessment of tissue which may improve diagnostic yield by guiding biopsy. Research and development continues to reduce the overall size of the imaging probe, increase the image acquisition speed, and improve resolution and field of view of confocal endomicroscopes. Technical advances will continue to enable application to less accessible organs and more complex systems in the body. Lateral and axial resolutions down to 0.5 μm and 3 μm, respectively, field of view as large as 800×450 μm, and objective lens and total probe outer diameters down to 350 μm and 1.25 mm, respectively, have been achieved. We provide a review of the historical developments of confocal imaging in vivo, the evolution of endomicroscope instrumentation, and the medical applications of confocal endomicroscopy. PMID:21994069

  15. A Pulse Coupled Neural Network Segmentation Algorithm for Reflectance Confocal Images of Epithelial Tissue

    PubMed Central

    Malik, Bilal H.; Jabbour, Joey M.; Maitland, Kristen C.

    2015-01-01

    Automatic segmentation of nuclei in reflectance confocal microscopy images is critical for visualization and rapid quantification of nuclear-to-cytoplasmic ratio, a useful indicator of epithelial precancer. Reflectance confocal microscopy can provide three-dimensional imaging of epithelial tissue in vivo with sub-cellular resolution. Changes in nuclear density or nuclear-to-cytoplasmic ratio as a function of depth obtained from confocal images can be used to determine the presence or stage of epithelial cancers. However, low nuclear to background contrast, low resolution at greater imaging depths, and significant variation in reflectance signal of nuclei complicate segmentation required for quantification of nuclear-to-cytoplasmic ratio. Here, we present an automated segmentation method to segment nuclei in reflectance confocal images using a pulse coupled neural network algorithm, specifically a spiking cortical model, and an artificial neural network classifier. The segmentation algorithm was applied to an image model of nuclei with varying nuclear to background contrast. Greater than 90% of simulated nuclei were detected for contrast of 2.0 or greater. Confocal images of porcine and human oral mucosa were used to evaluate application to epithelial tissue. Segmentation accuracy was assessed using manual segmentation of nuclei as the gold standard. PMID:25816131

  16. A pulse coupled neural network segmentation algorithm for reflectance confocal images of epithelial tissue.

    PubMed

    Harris, Meagan A; Van, Andrew N; Malik, Bilal H; Jabbour, Joey M; Maitland, Kristen C

    2015-01-01

    Automatic segmentation of nuclei in reflectance confocal microscopy images is critical for visualization and rapid quantification of nuclear-to-cytoplasmic ratio, a useful indicator of epithelial precancer. Reflectance confocal microscopy can provide three-dimensional imaging of epithelial tissue in vivo with sub-cellular resolution. Changes in nuclear density or nuclear-to-cytoplasmic ratio as a function of depth obtained from confocal images can be used to determine the presence or stage of epithelial cancers. However, low nuclear to background contrast, low resolution at greater imaging depths, and significant variation in reflectance signal of nuclei complicate segmentation required for quantification of nuclear-to-cytoplasmic ratio. Here, we present an automated segmentation method to segment nuclei in reflectance confocal images using a pulse coupled neural network algorithm, specifically a spiking cortical model, and an artificial neural network classifier. The segmentation algorithm was applied to an image model of nuclei with varying nuclear to background contrast. Greater than 90% of simulated nuclei were detected for contrast of 2.0 or greater. Confocal images of porcine and human oral mucosa were used to evaluate application to epithelial tissue. Segmentation accuracy was assessed using manual segmentation of nuclei as the gold standard.

  17. Laser multi-reflection confocal long focal-length measurement

    NASA Astrophysics Data System (ADS)

    Li, Zhigang; Qiu, Lirong; Zhao, Weiqian; Xiao, Yang

    2016-06-01

    We propose a new laser multi-reflection confocal focal-length measurement (MCFM) method to meet the requirements of a high-precision measurement for a long focal-length more than 2 m. It places an optical flat and a reflector behind the test lens for reflecting the measuring beam repeatedly, and then, uses the property that the peak points of confocal response curves precisely corresponds to the convergence points of a multi-reflected measuring beam to exactly identify the positions of the convergence points. Subsequently, it obtains the position variation of the reflector with a different number of reflections by a distance measuring instrument, and thereby achieving the high precise long focal-length measurement. The theoretical analyses and preliminary experimental results indicate that MCFM has a relative standard uncertainty of 0.066% for a test lens with the focal-length of 9.76 m. MCFM can provide a novel approach for the high-precision focal-length measurement.

  18. Emulation and design of terahertz reflection-mode confocal scanning microscopy based on virtual pinhole

    NASA Astrophysics Data System (ADS)

    Yang, Yong-fa; Li, Qi

    2014-12-01

    In the practical application of terahertz reflection-mode confocal scanning microscopy, the size of detector pinhole is an important factor that determines the performance of spatial resolution characteristic of the microscopic system. However, the use of physical pinhole brings some inconvenience to the experiment and the adjustment error has a great influence on the experiment result. Through reasonably selecting the parameter of matrix detector virtual pinhole (VPH), it can efficiently approximate the physical pinhole. By using this approach, the difficulty of experimental calibration is reduced significantly. In this article, an imaging scheme of terahertz reflection-mode confocal scanning microscopy that is based on the matrix detector VPH is put forward. The influence of detector pinhole size on the axial resolution of confocal scanning microscopy is emulated and analyzed. Then, the parameter of VPH is emulated when the best axial imaging performance is reached.

  19. In vivo reflectance confocal microscopy features of a melanoacanthoma

    PubMed Central

    Shahriari, Neda; Grant-Kels, Jane M.; Rabinovitz, Harold S.; Oliviero, Margaret; Scope, Alon

    2016-01-01

    Efforts have been expended to evaluate the reflectance confocal microscopy (RCM) features of different clinical entities in order to more thoroughly delineate benign versus malignant features. In this way, RCM can help clinicians to be more selective in regard to undertaking appropriate skin biopsies and improving their benign to malignant ratio. Herein, we report a case of a histopathologically proven melanoacanthoma, a variant of seborrheic keratosis. There are scarce reports describing the RCM features of melanoacanthoma. Our case demonstrated RCM features that were suspicious for melanoma. More RCM images of this benign entity are needed to establish definitive diagnostic criteria. PMID:27867743

  20. Confocal scanning beam laser microscope/macroscope: applications in fluorescence

    NASA Astrophysics Data System (ADS)

    Dixon, Arthur E.; Damaskinos, Savvas; Ribes, Alfonso

    1996-03-01

    A new confocal scanning beam laser microscope/macroscope is described that combines the rapid scan of a scanning beam laser microscope with the large specimen capability of a scanning stage microscope. This instrument combines an infinity-corrected confocal scanning laser microscope with a scanning laser macroscope that uses a telecentric f*(Theta) laser scan lens to produce a confocal imaging system with a resolution of 0.25 microns at a field of view of 25 microns and 5 microns at a field of view of 75,000 microns. The frame rate is 5 seconds per frame for a 512 by 512 pixel image, and 25 seconds for a 2048 by 2048 pixel image. Applications in fluorescence are discussed that focus on two important advantages of the instrument over a confocal scanning laser microscope: an extremely wide range of magnification, and the ability to image very large specimens. Examples are presented of fluorescence and reflected-light images of high quality printing, fluorescence images of latent fingerprints, packaging foam, and confocal autofluorescence images of a cricket.

  1. Segmentation of skin strata in reflectance confocal microscopy depth stacks

    NASA Astrophysics Data System (ADS)

    Hames, Samuel C.; Ardigò, Marco; Soyer, H. Peter; Bradley, Andrew P.; Prow, Tarl W.

    2015-03-01

    Reflectance confocal microscopy is an emerging tool for imaging human skin, but currently requires expert human assessment. To overcome the need for human experts it is necessary to develop automated tools for automatically assessing reflectance confocal microscopy imagery. This work presents a novel approach to this task, using a bag of visual words approach to represent and classify en-face optical sections from four distinct strata of the skin. A dictionary of representative features is learned from whitened and normalised patches using hierarchical spherical k-means. Each image is then represented by extracting a dense array of patches and encoding each with the most similar element in the dictionary. Linear discriminant analysis is used as a simple linear classifier. The proposed framework was tested on 308 depth stacks from 54 volunteers. Parameters are tuned using 10 fold cross validation on a training sub-set of the data, and final evaluation was performed on a held out test set. The proposed method generated physically plausible profiles of the distinct strata of human skin, and correctly classified 81.4% of sections in the test set.

  2. Confocal microscopy patterns in nonmelanoma skin cancer and clinical applications.

    PubMed

    González, S; Sánchez, V; González-Rodríguez, A; Parrado, C; Ullrich, M

    2014-06-01

    Reflectance confocal microscopy is currently the most promising noninvasive diagnostic tool for studying cutaneous structures between the stratum corneum and the superficial reticular dermis. This tool gives real-time images parallel to the skin surface; the microscopic resolution is similar to that of conventional histology. Numerous studies have identified the main confocal features of various inflammatory skin diseases and tumors, demonstrating the good correlation of these features with certain dermatoscopic patterns and histologic findings. Confocal patterns and diagnostic algorithms have been shown to have high sensitivity and specificity in melanoma and nonmelanoma skin cancer. Possible present and future applications of this noninvasive technology are wide ranging and reach beyond its use in noninvasive diagnosis. This tool can also be used, for example, to evaluate dynamic skin processes that occur after UV exposure or to assess tumor response to noninvasive treatments such as photodynamic therapy. We explain the characteristic confocal features found in the main nonmelanoma skin tumors and discuss possible applications for this novel diagnostic technique in routine dermatology practice.

  3. The use of reflectance confocal microscopy for examination of benign and malignant skin tumors

    PubMed Central

    Wielowieyska-Szybińska, Dorota; Białek-Galas, Kamila; Podolec, Katarzyna

    2014-01-01

    Reflectance confocal microscopy (RCM) is a modern, non-invasive diagnostic method that enables real-time imaging of epidermis and upper layers of the dermis with a nearly histological precision and high contrast. The application of this technology in skin imaging in the last few years has resulted in the progress of dermatological diagnosis, providing virtual access to the living skin erasing the need for conventional histopathology. The RCM has a potential of wide application in the dermatological diagnostic process with a particular reference to benign and malignant skin tumors. This article provides a summary of the latest reports and previous achievements in the field of RCM application in the diagnostic process of skin neoplasms. A range of dermatological indications and general characteristics of confocal images in various types of tumors are presented. PMID:25610353

  4. Biological applications of confocal fluorescence polarization microscopy

    NASA Astrophysics Data System (ADS)

    Bigelow, Chad E.

    Fluorescence polarization microscopy is a powerful modality capable of sensing changes in the physical properties and local environment of fluorophores. In this thesis we present new applications for the technique in cancer diagnosis and treatment and explore the limits of the modality in scattering media. We describe modifications to our custom-built confocal fluorescence microscope that enable dual-color imaging, optical fiber-based confocal spectroscopy and fluorescence polarization imaging. Experiments are presented that indicate the performance of the instrument for all three modalities. The limits of confocal fluorescence polarization imaging in scattering media are explored and the microscope parameters necessary for accurate polarization images in this regime are determined. A Monte Carlo routine is developed to model the effect of scattering on images. Included in it are routines to track the polarization state of light using the Mueller-Stokes formalism and a model for fluorescence generation that includes sampling the excitation light polarization ellipse, Brownian motion of excited-state fluorophores in solution, and dipole fluorophore emission. Results from this model are compared to experiments performed on a fluorophore-embedded polymer rod in a turbid medium consisting of polystyrene microspheres in aqueous suspension. We demonstrate the utility of the fluorescence polarization imaging technique for removal of contaminating autofluorescence and for imaging photodynamic therapy drugs in cell monolayers. Images of cells expressing green fluorescent protein are extracted from contaminating fluorescein emission. The distribution of meta-tetrahydroxypheny1chlorin in an EMT6 cell monolayer is also presented. A new technique for imaging enzyme activity is presented that is based on observing changes in the anisotropy of fluorescently-labeled substrates. Proof-of-principle studies are performed in a model system consisting of fluorescently labeled bovine

  5. Rapid diagnosis of tinea incognito using handheld reflectance confocal microscopy: a paradigm shift in dermatology?

    PubMed

    Navarrete-Dechent, Cristián; Bajaj, Shirin; Marghoob, Ashfaq A; Marchetti, Michael A

    2015-06-01

    Dermatophytoses are common skin infections. Traditional diagnostic tests such as skin scrapings for light microscopy examination, fungal cultures and biopsies remain imperfect due to false-negative test results, cost, time required to perform the procedure, time delays in test results and/or a requirement for an invasive procedure. Herein, we present a case of an 80-year-old female whose tinea incognito was non-invasively diagnosed within seconds using handheld reflectance confocal microscopy (RCM). As non-invasive skin imaging continues to improve, we expect light-based office microscopy to be replaced with technologies such as RCM, which has multiple and continually expanding diagnostic applications.

  6. Two-photon fluorescence and confocal reflected light imaging of thick tissue structures

    NASA Astrophysics Data System (ADS)

    Kim, Ki H.; So, Peter T. C.; Kochevar, Irene E.; Masters, Barry R.; Gratton, Enrico

    1998-04-01

    The technology of two-photon excitation has opened a window of opportunity for developing non-invasive medical diagnostic tools capable of monitoring thick tissue biochemical states. Using cellular endogenous chromophores, (beta) -nicotinamide- adenine dinucleotide phosphate [NAD(P)H], the cellular metabolic rates in living human skin were determined. Although important functional information can be obtained from the fluorescence spectroscopy of endogenous chromophores, these chromophores are rather poor contrast enhancing agent for mapping cellular morphology. First, most endogenous chromophores are confined to the cellular cytoplasm which prevents the visualization of other cellular organelles. Second, there is significant variability in the distribution and the quantum yield of endogenous chromophores which depends on tissue biochemistry but prevents consistent comparison of cellular morphology. On the other hand, the deep tissue cellular morphology has been imaged with excellent resolution using reflected light confocal microscopy. In reflected light microscopy, the image contrast originates from the index of refraction differences of the cellular structures. The organelle boundaries with significant index differences such as the plasma membrane and the nucleus envelope can be consistently visualized. A combination of morphological and functional information is required for a thorough tissue study. This presentation describes the development of a new microscope which is capable of simultaneously collecting both two-photon fluorescence and confocal reflected light signals. Promising biomedical applications include the non-invasive diagnosis of skin cancer and the study of wound healing.

  7. Development of in vivo confocal microscope for reflection and fluorescence imaging simultaneously

    NASA Astrophysics Data System (ADS)

    Ahn, MyoungKi; Chun, ByungSeon; Song, Cheol; Gweon, DaeGab

    2010-02-01

    In-vivo confocal microscope technology can be applied to the medical imaging diagnosis and new drug development. We present an in-vivo confocal microscope that can acquire a reflection image and a fluorescence image simultaneously and independently. To obtain reflection confocal images, we used a linearly polarized diode laser with the wavelength of 830 nm. To acquire fluorescence confocal images, we used two diode lasers with the wavelength of 488 nm and 660 nm, respectively. Because of a broad wavelength bandwidth from visible (488 nm) to near-IR (830 nm), we designed and optimized the optical system to reduce various optical aberrations. With the developed in-vivo confocal microscope, we performed ex-vivo cell imaging and in-vivo imaging of the human skin.

  8. Reflectance confocal endomicroscope with optical axial scanning for in vivo imaging of the oral mucosa

    PubMed Central

    Jabbour, Joey M.; Bentley, Julie L.; Malik, Bilal H.; Nemechek, John; Warda, John; Cuenca, Rodrigo; Cheng, Shuna; Jo, Javier A.; Maitland, Kristen C.

    2014-01-01

    This paper presents the design and evaluation of a reflectance confocal laser endomicroscope using a miniature objective lens within a rigid probe in conjunction with an electrically tunable lens for axial scanning. The miniature lens was characterized alone as well as in the endoscope across a 200 µm axial scan range using the tunable lens. The ability of the confocal endoscope to probe the human oral cavity is demonstrated by imaging of the oral mucosa in vivo. The results indicate that reflectance confocal endomicroscopy has the potential to be used in a clinical setting and guide diagnostic evaluation of biological tissue. PMID:25426310

  9. Reflectance confocal endomicroscope with optical axial scanning for in vivo imaging of the oral mucosa.

    PubMed

    Jabbour, Joey M; Bentley, Julie L; Malik, Bilal H; Nemechek, John; Warda, John; Cuenca, Rodrigo; Cheng, Shuna; Jo, Javier A; Maitland, Kristen C

    2014-11-01

    This paper presents the design and evaluation of a reflectance confocal laser endomicroscope using a miniature objective lens within a rigid probe in conjunction with an electrically tunable lens for axial scanning. The miniature lens was characterized alone as well as in the endoscope across a 200 µm axial scan range using the tunable lens. The ability of the confocal endoscope to probe the human oral cavity is demonstrated by imaging of the oral mucosa in vivo. The results indicate that reflectance confocal endomicroscopy has the potential to be used in a clinical setting and guide diagnostic evaluation of biological tissue.

  10. Reflectance confocal microscopy of red blood cells: simulation and experiment (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zeidan, Adel; Yeheskely-Hayon, Daniella; Minai, Limor; Yelin, Dvir

    2016-03-01

    The properties of red blood cells are a remarkable indicator of the body's physiological condition; their density could indicate anemia or polycythemia, their absorption spectrum correlates with blood oxygenation, and their morphology is highly sensitive to various pathologic states including iron deficiency, ovalocytosis, and sickle cell disease. Therefore, measuring the morphology of red blood cells is important for clinical diagnosis, providing valuable indications on a patient's health. In this work, we simulated the appearance of normal red blood cells under a reflectance confocal microscope and discovered unique relations between the cells' morphological parameters and the resulting characteristic interference patterns. The simulation results showed good agreement with in vitro reflectance confocal images of red blood cells, acquired using spectrally encoded flow cytometry (SEFC) that imaged the cells during linear flow and without artificial staining. By matching the simulated patterns to the SEFC images of the cells, the cells' three-dimensional shapes were evaluated and their volumes were calculated. Potential applications include measurement of the mean corpuscular volume, cell morphological abnormalities, cell stiffness under mechanical stimuli, and the detection of various hematological diseases.

  11. In vivo reflectance-mode confocal microscopy in clinical dermatology and cosmetology.

    PubMed

    González, S; Gilaberte-Calzada, Y

    2008-02-01

    In vivo reflectance confocal microscopy (RCM) is a non-invasive imaging tool that allows real-time visualization of cells and structures in living skin with near histological resolution. RCM has been used for the assessment of benign and malignant lesions, showing great potential for applications in basic skin research and clinical dermatology. RCM also reveals dynamic changes in the skin over time and in response to specific stimuli, like ultraviolet exposure, which makes it a promising tool in cosmetology, as it allows repetitive sampling without biopsy collection, causing no further damage to the areas under investigation. This review summarizes the latest advances in RCM, and its applications in the characterization of both normal and pathological skin.

  12. Confocal and Two-Photon Microscopy: Foundations, Applications and Advances

    NASA Astrophysics Data System (ADS)

    Diaspro, Alberto

    2001-11-01

    Confocal and Two-Photon Microscopy Foundations, Applications, and Advances Edited by Alberto Diaspro Confocal and two-photon fluorescence microscopy has provided researchers with unique possibilities of three-dimensional imaging of biological cells and tissues and of other structures such as semiconductor integrated circuits. Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances provides clear, comprehensive coverage of basic foundations, modern applications, and groundbreaking new research developments made in this important area of microscopy. Opening with a foreword by G. J. Brakenhoff, this reference gathers the work of an international group of renowned experts in chapters that are logically divided into balanced sections covering theory, techniques, applications, and advances, featuring: In-depth discussion of applications for biology, medicine, physics, engineering, and chemistry, including industrial applications Guidance on new and emerging imaging technology, developmental trends, and fluorescent molecules Uniform organization and review-style presentation of chapters, with an introduction, historical overview, methodology, practical tips, applications, future directions, chapter summary, and bibliographical references Companion FTP site with full-color photographs The significant experience of pioneers, leaders, and emerging scientists in the field of confocal and two-photon excitation microscopy Confocal and Two-Photon Microscopy: Foundations, Applications, and Advances is invaluable to researchers in the biological sciences, tissue and cellular engineering, biophysics, bioengineering, physics of matter, and medicine, who use these techniques or are involved in developing new commercial instruments.

  13. Consistency and distribution of reflectance confocal microscopy features for diagnosis of cutaneous T cell lymphoma

    NASA Astrophysics Data System (ADS)

    Lange-Asschenfeldt, Susanne; Babilli, Jasmin; Beyer, Marc; Ríus-Diaz, Francisca; González, Salvador; Stockfleth, Eggert; Ulrich, Martina

    2012-01-01

    Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Sézary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi2 analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi2 analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases.

  14. Anti-translational research: from the bedside back to the bench for reflectance confocal microscopy

    NASA Astrophysics Data System (ADS)

    Gareau, Daniel

    2014-03-01

    The reflectance confocal microscope has made translational progress in dermatology. 0.5 micrometer lateral resolution, 0.75mm field-of-view and excellent temporal resolution at ~15 frames/second serve the VivaScope well in the clinic, but it may be overlooked in basic research. This work reviews high spatiotemporal confocal microscopy and presents images acquired of various samples: zebra fish embryo where melanocytes with excellent contrast overly the spinal column, chicken embryo, where myocardium is seen moving at 15 frames/ second, calcium spikes in dendrites (fluorescence mode) just beyond the temporal resolution, and human skin where blood cells race through the artereovenous microvasculature. For an introduction to confocal microscopy, see: http://dangareau.net.s69818.gridserver.com/science/confocal-microscopy

  15. In vivo reflectance confocal microscopy features of a large cell acanthoma: report of a case

    PubMed Central

    Shahriari, Neda; Grant-Kels, Jane M.; Rabinovitz, Harold S.; Oliviero, Margaret; Scope, Alon

    2016-01-01

    Reflectance confocal microscopy (RCM) is an FDA approved noninvasive optical imaging technique that acquires cellular level-resolution skin images in vivo. Herein, we report a case of histopathologically proven large cell acanthoma (LCA) whose RCM features simulate those of squamous cell carcinoma in situ. PMID:27648388

  16. Comparison of Confocal and Super-Resolution Reflectance Imaging of Metal Oxide Nanoparticles

    PubMed Central

    Guggenheim, Emily J.; Khan, Abdullah; Pike, Jeremy; Chang, Lynne; Lynch, Iseult; Rappoport, Joshua Z.

    2016-01-01

    The potential for human exposure to manufactured nanoparticles (NPs) has increased in recent years, in part through the incorporation of engineered particles into a wide range of commercial goods and medical applications. NP are ideal candidates for use as therapeutic and diagnostic tools within biomedicine, however concern exists regarding their efficacy and safety. Thus, developing techniques for the investigation of NP uptake into cells is critically important. Current intracellular NP investigations rely on the use of either Transmission Electron Microscopy (TEM), which provides ultrahigh resolution, but involves cumbersome sample preparation rendering the technique incompatible with live cell imaging, or fluorescent labelling, which suffers from photobleaching, poor bioconjugation and, often, alteration of NP surface properties. Reflected light imaging provides an alternative non-destructive label free technique well suited, but not limited to, the visualisation of NP uptake within model systems, such as cells. Confocal reflectance microscopy provides optical sectioning and live imaging capabilities, with little sample preparation. However confocal microscopy is diffraction limited, thus the X-Y resolution is restricted to ~250 nm, substantially larger than the <100 nm size of NPs. Techniques such as super-resolution light microscopy overcome this fundamental limitation, providing increased X-Y resolution. The use of Reflectance SIM (R-SIM) for NP imaging has previously only been demonstrated on custom built microscopes, restricting the widespread use and limiting NP investigations. This paper demonstrates the use of a commercial SIM microscope for the acquisition of super-resolution reflectance data with X-Y resolution of 115 nm, a greater than two-fold increase compared to that attainable with RCM. This increase in resolution is advantageous for visualising small closely spaced structures, such as NP clusters, previously unresolvable by RCM. This is

  17. Use of a white light supercontinuum laser for confocal interference-reflection microscopy

    PubMed Central

    Chiu, L-D; Su, L; Reichelt, S; Amos, WB

    2012-01-01

    Shortly after its development, the white light supercontinuum laser was applied to confocal scanning microscopy as a more versatile substitute for the multiple monochromatic lasers normally used for the excitation of fluorescence. This light source is now available coupled to commercial confocal fluorescence microscopes. We have evaluated a supercontinuum laser as a source for a different purpose: confocal interferometric imaging of living cells and artificial models by interference reflection. We used light in the range 460–700 nm where this source provides a reasonably flat spectrum, and obtained images free from fringe artefacts caused by the longer coherence length of conventional lasers. We have also obtained images of cytoskeletal detail that is difficult to see with a monochromatic laser. PMID:22432542

  18. Use of a white light supercontinuum laser for confocal interference-reflection microscopy.

    PubMed

    Chiu, L-D; Su, L; Reichelt, S; Amos, W B

    2012-05-01

    Shortly after its development, the white light supercontinuum laser was applied to confocal scanning microscopy as a more versatile substitute for the multiple monochromatic lasers normally used for the excitation of fluorescence. This light source is now available coupled to commercial confocal fluorescence microscopes. We have evaluated a supercontinuum laser as a source for a different purpose: confocal interferometric imaging of living cells and artificial models by interference reflection. We used light in the range 460-700 nm where this source provides a reasonably flat spectrum, and obtained images free from fringe artefacts caused by the longer coherence length of conventional lasers. We have also obtained images of cytoskeletal detail that is difficult to see with a monochromatic laser.

  19. Fluorescence lifetime imaging and reflectance confocal microscopy for multiscale imaging of oral precancer.

    PubMed

    Jabbour, Joey M; Cheng, Shuna; Malik, Bilal H; Cuenca, Rodrigo; Jo, Javier A; Wright, John; Cheng, Yi-Shing Lisa; Maitland, Kristen C

    2013-04-01

    Optical imaging techniques using a variety of contrast mechanisms are under evaluation for early detection of epithelial precancer; however, tradeoffs in field of view (FOV) and resolution may limit their application. Therefore, we present a multiscale multimodal optical imaging system combining macroscopic biochemical imaging of fluorescence lifetime imaging (FLIM) with subcellular morphologic imaging of reflectance confocal microscopy (RCM). The FLIM module images a 16×16 mm² tissue area with 62.5 μm lateral and 320 ps temporal resolution to guide cellular imaging of suspicious regions. Subsequently, coregistered RCM images are acquired at 7 Hz with 400 μm diameter FOV, <1  μm lateral and 3.5 μm axial resolution. FLIM-RCM imaging was performed on a tissue phantom, normal porcine buccal mucosa, and a hamster cheek pouch model of oral carcinogenesis. While FLIM is sensitive to biochemical and macroscopic architectural changes in tissue, RCM provides images of cell nuclear morphology, all key indicators of precancer progression.

  20. Reflective confocal laser scanning microscopy and nonlinear microscopy of cross-linked rabbit cornea

    NASA Astrophysics Data System (ADS)

    Krueger, Alexander; Hovakimyan, Marina; Ramirez, Diego F.; Stachs, Oliver; Guthoff, Rudolf F.; Heisterkamp, Alexander

    2009-07-01

    Cross-linking of the cornea with application of Ribovlavin and UV-A light is an evolving clinical treatment of the eye disease keratoconus. Despite the positive clinical track record of corneal cross-linking, the complex wound healing process after the treatment is still under investigation. In this study an animal model was used to clarify the state of wound healing 5 weeks after treatment. Cross-linked rabbit corneae were imaged with reflective confocal laser scanning and nonlinear microscopy, namely second harmonic imaging microscopy (SHIM) and two-photon excited autofluorescence. First results show that the NAD(P) H-autofluorescence of the corneal keratocytes and their scattering signal still show a signature of the treatment five weeks after the cross-linking procedure. The SHIM signals show the structural morphology of the fibrous collagen sheets in the stroma of the cornea. SHIM detected in the forward direction differs substantially from backward SHIM, but no signature of treatment was found in both detection channels of the SHIM signal.

  1. Characterization of hydrogel microstructure using laser tweezers particle tracking and confocal reflection imaging

    NASA Astrophysics Data System (ADS)

    Kotlarchyk, M. A.; Botvinick, E. L.; Putnam, A. J.

    2010-05-01

    Hydrogels are commonly used as extracellular matrix mimetics for applications in tissue engineering and increasingly as cell culture platforms with which to study the influence of biophysical and biochemical cues on cell function in 3D. In recent years, a significant number of studies have focused on linking substrate mechanical properties to cell function using standard methodologies to characterize the bulk mechanical properties of the hydrogel substrates. However, current understanding of the correlations between the microstructural mechanical properties of hydrogels and cell function in 3D is poor, in part because of a lack of appropriate techniques. Here we have utilized a laser tracking system, based on passive optical microrheology instrumentation, to characterize the microstructure of viscoelastic fibrin clots. Trajectories and mean square displacements were observed as bioinert PEGylated (PEG: polyethylene glycol) microspheres (1, 2 or 4.7 µm in diameter) diffused within confined pores created by the protein phase of fibrin hydrogels. Complementary confocal reflection imaging revealed microstructures comprised of a highly heterogeneous fibrin network with a wide range of pore sizes. As the protein concentration of fibrin gels was increased, our quantitative laser tracking measurements showed a corresponding decrease in particle mean square displacements with greater resolution and sensitivity than conventional imaging techniques. This platform-independent method will enable a more complete understanding of how changes in substrate mechanical properties simultaneously influence other microenvironmental parameters in 3D cultures.

  2. Characterization of hydrogel microstructure using laser tweezers particle tracking and confocal reflection imaging.

    PubMed

    Kotlarchyk, M A; Botvinick, E L; Putnam, A J

    2010-05-19

    Hydrogels are commonly used as extracellular matrix mimetics for applications in tissue engineering and increasingly as cell culture platforms with which to study the influence of biophysical and biochemical cues on cell function in 3D. In recent years, a significant number of studies have focused on linking substrate mechanical properties to cell function using standard methodologies to characterize the bulk mechanical properties of the hydrogel substrates. However, current understanding of the correlations between the microstructural mechanical properties of hydrogels and cell function in 3D is poor, in part because of a lack of appropriate techniques. Here we have utilized a laser tracking system, based on passive optical microrheology instrumentation, to characterize the microstructure of viscoelastic fibrin clots. Trajectories and mean square displacements were observed as bioinert PEGylated (PEG: polyethylene glycol) microspheres (1, 2 or 4.7 μm in diameter) diffused within confined pores created by the protein phase of fibrin hydrogels. Complementary confocal reflection imaging revealed microstructures comprised of a highly heterogeneous fibrin network with a wide range of pore sizes. As the protein concentration of fibrin gels was increased, our quantitative laser tracking measurements showed a corresponding decrease in particle mean square displacements with greater resolution and sensitivity than conventional imaging techniques. This platform-independent method will enable a more complete understanding of how changes in substrate mechanical properties simultaneously influence other microenvironmental parameters in 3D cultures.

  3. Application of Confocal and Spectrally Resolved Techniques to Scanning Laser Photoluminescence Microscopy.

    NASA Astrophysics Data System (ADS)

    Bowron, John William

    Both confocal microscopes and photoluminescence wafer mapping systems are well-developed technologies, however the application of confocal techniques to photoluminescence microscopy is not common in the literature. While developing this microscope a novel design for a spectrally-resolved detection arm was implemented. The microscope shows full confocal capabilities in reflected light operation, good spectral sensitivity in the visible region and a range of possible spectral resolutions between 10 nm and 0.1 nm, however the axial response in photoluminescence operation was found to be broader than expected by a factor of two. Calculations were performed to model and understand the new microscope. Simulations of the axial-response of an infinity-connected microscope in reflected light agreed well with experimental data. A new prediction showed that under certain circumstances the maximum signal is not always obtained at best focus. This prediction was confirmed later by experiment. These calculations were extended to understand the broadening observed in photoluminescence imaging. Three factors were considered: absorption in the material, diffusion of photo-excited carriers and the high refractive index of the material. The utility of the microscope was demonstrated by using it to image several different samples. Near-infrared fluorescence imaging was demonstrated for a stained biological specimen. Auto-fluorescence imaging was demonstrated using an ultra-violet laser and spectrally-resolved images were used to distinguish between various materials in the specimen. Confocal image stacking was demonstrated in photoluminescence on a CuO sample. Confocal photoluminescence images were shown to have higher spatial resolution than non-confocal images. Quantitative information was obtained for a SiC sample containing several polytypes. The optical measurements were then correlated with X-ray diffraction measurements in order to arrive at a polytype identification scheme

  4. Near-IR fluorescence and reflectance confocal microscopy for imaging of quantum dots in mammalian skin

    PubMed Central

    Mortensen, Luke J.; Glazowski, Christopher E.; Zavislan, James M.; DeLouise, Lisa A.

    2011-01-01

    Understanding the skin penetration of nanoparticles (NPs) is an important concern due to the increasing presence of NPs in consumer products, including cosmetics. Technical challenges have slowed progress in evaluating skin barrier and NP factors that contribute to skin penetration risk. To limit sampling error and other problems associated with histological processing, many researchers are implementing whole tissue confocal or multiphoton microscopies. This work introduces a fluorescence and reflectance confocal microscopy system that utilizes near-IR excitation and emission to detect near-IR lead sulfide quantum dots (QDs) through ex vivo human epidermis. We provide a detailed prediction and experimental analysis of QD detection sensitivity and demonstrate detection of QD skin penetration in a barrier disrupted model. The unique properties of near-IR lead-based QDs will enable future studies that examine the impact of further barrier-disrupting agents on skin penetration of QDs and elucidate mechanistic insight into QD tissue interactions at the cellular level. PMID:21698023

  5. [Application of confocal laser scanning microscope in forensic pathology].

    PubMed

    Zhuo, Luo; Hu, Le-Sheng; Zhou, Lan; Zheng, Na; Liang, Man; Yang, Fan; Liu, Liang

    2009-12-01

    Confocal laser scanning microscopy(CLSM) is a new technique for microscopic imaging, which can collect the transverse section image of the samples and produce three-dimensional reconstruction and present higher spatial resolution than the conventional light microscope. As a precision instrument for the microscopic image, it plays an important role in forensic pathology. The article reviews the recent research achievements from sudden cardiac death, bullet wound and nervous system damage, etc, and explores the potential applications of the forensic pathology research and forensic practice.

  6. Living matter observations with a novel hyperspectral supercontinuum confocal microscope for VIS to near-IR reflectance spectroscopy.

    PubMed

    Bertani, Francesca R; Ferrari, Luisa; Mussi, Valentina; Botti, Elisabetta; Costanzo, Antonio; Selci, Stefano

    2013-10-25

    A broad range hyper-spectroscopic microscope fed by a supercontinuum laser source and equipped with an almost achromatic optical layout is illustrated with detailed explanations of the design, implementation and data. The real novelty of this instrument, a confocal spectroscopic microscope capable of recording high resolution reflectance data in the VIS-IR spectral range from about 500 nm to 2.5 μm wavelengths, is the possibility of acquiring spectral data at every physical point as defined by lateral coordinates, X and Y, as well as at a depth coordinate, Z, as obtained by the confocal optical sectioning advantage. With this apparatus we collect each single scanning point as a whole spectrum by combining two linear spectral detector arrays, one CCD for the visible range, and one InGaAs infrared array, simultaneously available at the sensor output channel of the home made instrument. This microscope has been developed for biomedical analysis of human skin and other similar applications. Results are shown illustrating the technical performances of the instrument and the capability in extracting information about the composition and the structure of different parts or compartments in biological samples as well as in solid statematter. A complete spectroscopic fingerprinting of samples at microscopic level is shown possible by using statistical analysis on raw data or analytical reflectance models based on Abelés matrix transfer methods.

  7. Living Matter Observations with a Novel Hyperspectral Supercontinuum Confocal Microscope for VIS to Near-IR Reflectance Spectroscopy

    PubMed Central

    Bertani, Francesca R.; Ferrari, Luisa; Mussi, Valentina; Botti, Elisabetta; Costanzo, Antonio; Selci, Stefano

    2013-01-01

    A broad range hyper-spectroscopic microscope fed by a supercontinuum laser source and equipped with an almost achromatic optical layout is illustrated with detailed explanations of the design, implementation and data. The real novelty of this instrument, a confocal spectroscopic microscope capable of recording high resolution reflectance data in the VIS-IR spectral range from about 500 nm to 2.5 μm wavelengths, is the possibility of acquiring spectral data at every physical point as defined by lateral coordinates, X and Y, as well as at a depth coordinate, Z, as obtained by the confocal optical sectioning advantage. With this apparatus we collect each single scanning point as a whole spectrum by combining two linear spectral detector arrays, one CCD for the visible range, and one InGaAs infrared array, simultaneously available at the sensor output channel of the home made instrument. This microscope has been developed for biomedical analysis of human skin and other similar applications. Results are shown illustrating the technical performances of the instrument and the capability in extracting information about the composition and the structure of different parts or compartments in biological samples as well as in solid statematter. A complete spectroscopic fingerprinting of samples at microscopic level is shown possible by using statistical analysis on raw data or analytical reflectance models based on Abelés matrix transfer methods. PMID:24233077

  8. In vivo fibered confocal reflectance imaging: totally non-invasive morphological cellular imaging brought to the endoscopist

    NASA Astrophysics Data System (ADS)

    Osdoit, Anne; Genet, Magalie; Perchant, Aymeric; Loiseau, Sacha; Abrat, Benjamin; Lacombe, François

    2006-02-01

    This paper presents a novel fibered confocal reflectance microscopy system (FCRM) specifically designed for the medical observation of biological tissues in vivo and in situ, in real time, at the cellular level: the R-600. Reflectance imaging is based on the refraction index difference between biological components while confocal imaging allow to perform the optical sectioning slice in-depth inside the tissues. The R-600 is based on a proximal scanning system, coupled with a 7 mm diameter probe made of tens of thousands of flexible optical fibers allowing in situ imaging, associated with a dedicated software performing real-time control and image processing. The R-600 provides 12 frames per second at an optical imaging depth of 30 microns, with a high lateral resolution, 1 micron, an axial resolution of 2 microns in a field of view 160 microns in diameter. Thanks to the miniaturization of the optical probe, unprecedented accessibility is made possible in organs such as the cervix or the otolaryngological sphere, in a completely non-invasive fashion. The aim of FCRM is to perform optical biopsy. As a first step towards this goal, we present here results obtained in vivo and in real-time on a human mouth , assessing the ability of the R-600 to perform rapid morphologic examination. Subcellular structures such as nuclei and membranes can be clearly distinguished on the images. Further miniaturization opens perspectives for an integrated endoscope-compatible system with broad medical applications.

  9. In vivo analysis of solar lentigines by reflectance confocal microscopy before and after Q-switched ruby laser treatment.

    PubMed

    Richtig, Erika; Hofmann-Wellenhof, Rainer; Kopera, Daisy; El-Shabrawi-Caelen, Laila; Ahlgrimm-Siess, Verena

    2011-03-01

    Solar lentigines are benign lesions usually found on sun-damaged skin. We investigated twelve cases of solar lentigines through dermoscopy and reflectance confocal microscopy, performed before, and 30 min and 10 days after, a single treatment with a Q-switched ruby laser. At baseline, all lesions showed characteristic features of solar lentigines in reflectance confocal microscopy analysis: regular honeycomb patterns, edged dermal papillae and cord-like rete ridges at the dermoepidermal junction. Thirty minutes post-laser treatment, blurred epidermal intercellular connections, dark structureless areas of different sizes and shapes in the lower epidermal layers, and hyporeflective dermal papillae, reflecting epidermal and dermal oedema, were observed. Ten days post-treatment highly reflective round-to polygonal areas and aggregated granules, representing extracellular melanin, were detected in all epidermal layers featuring regular honeycomb patterns. Reflectance confocal microscopy can be used to visualise dynamic skin processes, allowing non-invasive in vivo follow-up of skin lesions after treatment.

  10. The application of dermal papillary rings in dermatology by in vivo confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Xiang, W. Z.; Xu, A. E.; Xu, J.; Bi, Z. G.; Shang, Y. B.; Ren, Q. S.

    2010-08-01

    Confocal laser scanning microscopy (CLSM) allows noninvasive visualization of human skin in vivo, without needing to fix or section the tissue. Melanocytes and pigmented keratinocytes at the level of the basal layer form bright dermal papillary rings which are readily amenable to identify in confocal images. Our purpose was to explore the role of dermal papillary rings in assessment of lesion location, the diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. Seventy-one patients were imaged with the VivaScope 1500 reflectance confocal microscope provided by Lucid, Inc. The results indicate that dermal papillary rings can assess the location of lesion; the application of dermal papillary rings can provide diagnostic support and differential diagnosis for vitiligo, nevus depigmentosus, tinea versicolor, halo nevus, common nevi, and assess the therapeutic efficacy of NBUVB phototherapy plus topical 0.1 percent tacrolimus ointment for vitiligo. In conclusion, our findings indicate that the dermal papillary rings play an important role in the assessment the location of lesion, diagnosis, differential diagnosis of lesions and assessment of therapeutic efficacy by in vivo CLSM. CLSM may be a promising tool for noninvasive examination in dermatology. However, larger studies are needed to expand the application of dermal papillary rings in dermatology.

  11. High numerical aperture microendoscope objective for a fiber confocal reflectance microscope

    NASA Astrophysics Data System (ADS)

    Kester, Robert T.; Tkaczyk, Tomasz S.; Descour, Michael R.; Christenson, Todd; Richards-Kortum, Rebecca

    2007-03-01

    A disposable high numerical aperture microendoscope objective has been designed, fabricated, and tested for use with a fiber confocal reflectance microscope. The objective uses high precision LIGA fabricated components to integrate imaging components and hydraulic suction lines into a housing that measures only 3.85 mm in outer diameter and 14.65 mm in length. The hydraulics are used to translate tissue through the focal plane for three dimensional imaging. This device is diffraction limited for λ = 850 nm, has a numerical aperture of 1.0, a field of view of 250 µm, and a working distance of 450 µm. The objective is intended for in vivo imaging of precancerous cells.

  12. The use of reflectance confocal microscopy for monitoring response to therapy of skin malignancies

    PubMed Central

    Ulrich, Martina; Lange-Asschenfeldt, Susanne; Gonzalez, Salvador

    2012-01-01

    Summary Reflectance confocal microscopy (RCM) is a new non-invasive imaging technique that enables visualizing cells and structures in living skin in real-time with resolution close to that of histological analysis. RCM has been successfully implemented in the assessment of benign and malignant lesions. Most importantly, it also enables monitoring dynamic changes in the skin over time and in response to different therapies, e.g., imiquimod, photodynamic therapy, and others. Given the often traumatic nature of skin cancer that affects both the physiology and the psychology of the patients, it is crucial to have methods that enable monitoring the response to treatment but that minimize the distress and discomfort associated with such process. This article provides a very brief overview of the fundamentals of RCM and then focuses on its recent employment as a monitoring tool in skin cancer and other pathologies that may require frequent follow-up. PMID:23785598

  13. Coherent artifact suppression in line-field reflection confocal microscopy using a low spatial coherence light source.

    PubMed

    Liu, Changgeng; Cao, Hui; Choma, Michael A

    2016-10-15

    Line-field reflection confocal microscopy (LF-RCM) has the potential to add a dimension of parallelization to traditional confocal microscopy while reducing the need for two-axis beam scanning. LF-RCM systems often employ light sources with a high degree of spatial coherence. This high degree of spatial coherence potentially leads to unwanted coherent artifact in the setting of nontrivial sample scattering. Here, we (a) confirm that a coherent artifact is a nontrivial problem in LF-RCM when using spatially coherent light, and (b) demonstrate that such a coherent artifact can be mitigated through the use of reduced spatial coherence line-field sources. We demonstrate coherent noise suppression in a full-pupil line-field confocal microscope using a large number of mutually incoherent emitters from a vertical-cavity surface-emitting lasers (VCSEL) array. The coherent noise from a highly scattering sample is significantly suppressed by the use of this synthesized reduced spatial coherence light source compared to a fully coherent light source. Lastly, with scattering samples, the axial confocality of line-field confocal microscopy is compromised independent of the source spatial coherence, as demonstrated by our experimental result. Our results highlight the importance of spatial coherence engineering in parallelized reflection confocal microscopy.

  14. Application of a novel confocal imaging technique for early the detection of dental decay

    NASA Astrophysics Data System (ADS)

    Rousseau, Christel; Girkin, John M.; Vaidya, Shilpa; Hall, Andrew F.; Whitters, C. J.; Creanor, Steve L.

    2002-06-01

    In order to stop or prevent the progression of dental disease, early detection and quantification of decay are crucially important. Dental decay (caries) detection methods have traditionally involved clinical examination by eye, using probes and dental radiography, but up to 60% of lesions are missed. What the dentist requires is a cheap, reliable method of detection of early disease, ideally with information on the depth and rate of growth or healing. Conventional commercial scanning confocal microscopes are unsuitable for use on dental patients. We report on a fibre optic based confocal microscope designed for in vivo examination of caries lesions. The system utilizes a common fibre both as the source and to detect the reflected confocal signal. The initial system has been optimized using dielectric mirrors and the thickness of the stack has been measured with high precision. Dental samples have been examined and the system has been demonstrated to provide information on the depth and mineral loss of a lesion. Fibre optic microscopy (FOCM) demonstrates a practical route to developing an in vivo caries profiler. In this paper, the FOCM and its applications in caries detection are described and the potential of this scheme as a practical dental probe is discussed.

  15. Determine scattering coefficient and anisotropy of scattering of murine tissues using reflectance-mode confocal microscopy

    NASA Astrophysics Data System (ADS)

    Samatham, Ravikant; Jacques, Steven L.

    2013-02-01

    Different techniques have been developed to determine the optical properties of turbid media, which include collimated transmission, diffuse reflectance, adding-doubling and goniometry. While goniometry can be used to determine the anisotropy of scattering (g), other techniques are used to measure the absorption coefficient and reduced scattering coefficient (μs(1-g)). But separating scattering coefficient (μs) and anisotropy of scattering from reduced scattering coefficient has been tricky. We developed an algorithm to determine anisotropy of scattering from the depth dependent decay of reflectance-mode confocal scanning laser microscopy (rCSLM) data. This report presents the testing of the algorithm on tissue phantoms with different anisotropies (g = 0.127 to 0.868, at 488 nm wavelength). Tissue phantoms were made from polystyrene microspheres (6 sizes 0.1-0.5 μm dia.) dispersed in both aqueous solutions and agarose gels. Three dimensional images were captured. The rCSLM-signal followed an exponential decay as a function of depth of the focal volume, R(z)ρexp(-μz) where ρ (dimensionless, ρ = 1 for a mirror) is the local reflectivity and μ [cm-1] is the exponential decay constant. The theory was developed to uniquely map the experimentally determined μ and ρ into the optical scattering properties μs and g. The values of μs and g depend on the composition and microstructure of tissues, and allow characterization of a tissue.

  16. Performance of full-pupil line-scanning reflectance confocal microscopy in human skin and oral mucosa in vivo

    PubMed Central

    Larson, Bjorg; Abeytunge, Sanjeewa; Rajadhyaksha, Milind

    2011-01-01

    Point-scanning reflectance confocal microscopes continue to be successfully translated for detection of skin cancer. Line-scanning, with the use of a single scanner and a linear-array detector, offers a potentially smaller, simpler and lower cost alternative approach, to accelerate widespread dissemination into the clinic. However, translation will require an understanding of imaging performance deep within scattering and aberrating human tissues. We report the results of an investigation of the performance of a full-pupil line-scanning reflectance confocal microscope in human skin and oral mucosa, in terms of resolution, optical sectioning, contrast, signal-to-noise ratio, imaging and the effect of speckle noise. PMID:21750780

  17. Virtual pinhole confocal microscope

    SciTech Connect

    George, J.S.; Rector, D.M.; Ranken, D.M.; Peterson, B.; Kesteron, J.

    1999-06-01

    Scanned confocal microscopes enhance imaging capabilities, providing improved contrast and image resolution in 3-D, but existing systems have significant technical shortcomings and are expensive. Researchers at Los Alamos National Laboratory have developed a novel approach--virtual pinhole confocal microscopy--that uses state of the art illumination, detection, and data processing technologies to produce an imager with a number of advantages: reduced cost, faster imaging, improved efficiency and sensitivity, improved reliability and much greater flexibility. Work at Los Alamos demonstrated proof of principle; prototype hardware and software have been used to demonstrate technical feasibility of several implementation strategies. The system uses high performance illumination, patterned in time and space. The authors have built functional confocal imagers using video display technologies (LCD or DLP) and novel scanner based on a micro-lens array. They have developed a prototype system for high performance data acquisition and processing, designed to support realtime confocal imaging. They have developed algorithms to reconstruct confocal images from a time series of spatially sub-sampled images; software development remains an area of active development. These advances allow the collection of high quality confocal images (in fluorescence, reflectance and transmission modes) with equipment that can inexpensively retrofit to existing microscopes. Planned future extensions to these technologies will significantly enhance capabilities for microscopic imaging in a variety of applications, including confocal endoscopy, and confocal spectral imaging.

  18. [Application of depth-analysis of confocal Raman micro-spectroscopy to chirography identification].

    PubMed

    Lin, Hai-Bo; Xu, Xiao-Xuan; Wang, Bin; Yang, Yan-Yong; Yu, Gang; Zhang, Cun-Zhou; Li, Jie

    2005-01-01

    Depth analysis of confocal Raman micro-spectroscopy was applied to chirography identification. The result indicated that depth analysis has potential application to forensic science field, especially in longitudinal identification of ink and inkpad. No matter what the spatial distributions of the signature pen and inkpad are, confocal Raman micro-spectroscopy can longitudinally distinguish those spatial differences. All those suggested that confocal Raman micro-spectroscopy is a fast, simple, high sensitive and non-destructive technique.

  19. Investigation by in vivo reflectance confocal microscopy: melanocytes at the edges of solar lentigines.

    PubMed

    Nakajima, Akiko; Funasaka, Yoko; Kawana, Seiji

    2012-07-01

    In vivo reflectance confocal microscopy (RCM) provides high-resolution, real-time optical sections of the skin in a non-invasive manner, allowing visualization of the skin in its native state. Highly reflective skin components including melanin, collagen and keratin appear bright (white) in RCM images. RCM examination of solar lentigines is known to show features that correlate well with histologic findings such as supranuclear melanin caps, but there are a limited number of reports on melanocyte dendrites. In this study, we utilized RCM to investigate the melanocyte dendricity and distribution within solar lentigines. Seventeen healthy Japanese females who had fairly large solar lentigines on their faces were recruited to join our clinical study, and we examined them by using RCM on their non-lesional areas, and the inside and the outer rim of the lesional areas. As a result, we discovered that dendritic melanocytes were rarely seen in the center of a solar lentigo (SL), but were seen at a very high frequency in the outer rim of a SL. The results suggest that the melanocytes are more active at the edge of a SL, produce more melanin, and often spread their dendrites widely in a horizontal direction. The findings in this report might shed light on the dynamic pathomechanisms of solar lentigines in vivo.

  20. In vivo reflectance confocal microscopy detects pigmentary changes in melasma at a cellular level resolution.

    PubMed

    Kang, Hee Young; Bahadoran, Philippe; Suzuki, Itaru; Zugaj, Didier; Khemis, Abdallah; Passeron, Thierry; Andres, Philippe; Ortonne, Jean-Paul

    2010-08-01

    Melasma is a frequent pigmentary disorder caused by abnormal melanin deposits in the skin. In vivo reflectance confocal microscopy (RCM) is a repetitive imaging tool that provides real-time images of the skin at nearly histological resolution. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders are the most suitable candidates for RCM examination but RCM features of melasma have never been reported. This study investigates the pilot use of RCM in melasma to provide a set of well-described morphological criteria with histological correlations. RCM images were acquired from melasma skin and compared to adjacent control skin in 26 patients. Skin biopsies were obtained from eight patients. In the epidermis, RCM showed in all patients a significant increase in hyperrefractile cobblestoning cells. These cells corresponded to hyperpigmented basal keratinocytes in histology. In six patients, dendritic cells corresponding to activated melanocytes were also found in the epidermis. In the dermis, RCM identified in nine patients plump bright cells corresponding to melanophages. Interestingly, for a given patient, the topographic distribution of melanophages in melasma lesions was very heterogeneous. RCM also showed a significant increase in solar elastosis and blood vessels in the dermis. RCM is a non-invasive technique that detects pigmentary changes in melasma at a cellular level resolution. Therefore, RCM provides an innovative way to classify melasma by pigment changes.

  1. Image segmentation for integrated multiphoton microscopy and reflectance confocal microscopy imaging of human skin in vivo

    PubMed Central

    Chen, Guannan; Lui, Harvey

    2015-01-01

    Background Non-invasive cellular imaging of the skin in vivo can be achieved in reflectance confocal microscopy (RCM) and multiphoton microscopy (MPM) modalities to yield complementary images of the skin based on different optical properties. One of the challenges of in vivo microscopy is the delineation (i.e., segmentation) of cellular and subcellular architectural features. Methods In this work we present a method for combining watershed and level-set models for segmentation of multimodality images obtained by an integrated MPM and RCM imaging system from human skin in vivo. Results Firstly, a segmentation model based on watershed is introduced for obtaining the accurate structure of cell borders from the RCM image. Secondly,, a global region based energy level-set model is constructed for extracting the nucleus of each cell from the MPM image. Thirdly, a local region-based Lagrange Continuous level-set approach is used for segmenting cytoplasm from the MPM image. Conclusions Experimental results demonstrated that cell borders from RCM image and boundaries of cytoplasm and nucleus from MPM image can be obtained by our segmentation method with better accuracy and effectiveness. We are planning to use this method to perform quantitative analysis of MPM and RCM images of in vivo human skin to study the variations of cellular parameters such as cell size, nucleus size and other mophormetric features with skin pathologies. PMID:25694949

  2. Progress in reflectance confocal microscopy for imaging oral tissues in vivo

    NASA Astrophysics Data System (ADS)

    Peterson, Gary; Zanoni, Daniella K.; Migliacci, Jocelyn; Cordova, Miguel; Rajadhyaksha, Milind; Patel, Snehal

    2016-02-01

    We report progress in development and feasibility testing of reflectance confocal microscopy (RCM) for imaging in the oral cavity of humans. We adapted a small rigid relay telescope (120mm long x 14mm diameter) and a small water immersion objective lens (12mm diameter, NA 0.7) to a commercial handheld RCM scanner (Vivascope 3000, Caliber ID, Rochester NY). This scanner is designed for imaging skin but we adapted the front end (the objective lens and the stepper motor that axially translates) for intra-oral use. This adaption required a new approach to address the loss of the automated stepper motor for acquisition of images in depth. A helical spring-like cap (with a coverslip to contact tissue) was designed for approximately 150 um of travel. Additionally other methods for focusing optics were designed and evaluated. The relay telescope optics is being tested in a clinical setting. With the capture of video and "video-mosaicing", extended areas can be imaged. The feasibility of imaging oral tissues was initially investigated in volunteers. RCM imaging in buccal mucosa in vivo shows nuclear and cellular detail in the epithelium and epithelial junction, and connective tissue and blood flow in the underlying lamina propria. Similar detail, including filiform and fungiform papillae, can be seen on the tongue in vivo. Clinical testing during head and neck surgery is now in progress and patients are being imaged for both normal tissue and cancerous margins in lip and tongue mucosa.

  3. Analysis of surface microtopography of biodegradable polymer matrices using confocal reflection microscopy.

    PubMed

    Semler, E J; Tjia, J S; Moghe, P V

    1997-01-01

    Currently, synthetic degradable polymers are frequently employed as culture substrates prior to cell transplantation and as implantable scaffolds for cellular infiltration during soft and hard tissue repair. The surface microstructure of matrices based on such polymers may be important in controlling cellular anchorage, spreading, and growth on the external surface, as well as infiltration into the voids of porous polymer scaffolds. While the chemistry, bulk structure, and mechanical properties of such polymers have been extensively studied, the surface microstructure has not yet been systematically examined, particularly following polymer degradation. In this study, we present the first account of the use of confocal laser-scanning reflection microscopy (CLSM) to visualize and quantitate the microtopography of the surface of porous matrices of poly(lactic acid)/poly(glycolic acid) (PLAGA) copolymers following polymer degradation. Utilizing this technique, we report that the surface morphology of PLAGA matrices changes significantly upon degradation, with increased local clustering of textured regions. Our quantitative analysis suggests that polymer degradation results in a lower spatially-averaged surface roughness, with significant cyclical variations observed at later time points. The computed surface correlation function was observed to increase upon degradation, confirming the results from our morphological studies. Finally, we demonstrate the efficacy of CLSM to concomitantly image both the polymer surface and locally attached cells, in real time.

  4. In vivo reflectance confocal microscopy evaluation of cheilitis glandularis: a report of 5 cases.

    PubMed

    Lourenço, Silvia V; Kos, Eliana; Borguezan Nunes, Thais; Bologna, Sheyla B; Sangueza, Martin; Nico, Marcello M S

    2015-03-01

    Cheilitis glandularis (CG) is an uncommon condition of unknown origin; it is clinically characterized by variable degrees of macrocheilia associated with red dilated ostia of minor salivary glands on the vermilion area, which secrete viscous saliva. Histopathological characteristics of CG are comprised of chronic sialadenitis with engorged acinar lobules and dilated ducts; CG also features chronic sun damage (actinic cheilitis and squamous cell carcinoma). These changes may be localized, and a punch biopsy specimen might fail to reveal enough criteria to support the diagnosis of CG. Reflectance confocal microscopy (RCM) is a noninvasive imaging technique that enables an in vivo en face visualization of tissues with a resolution close to conventional histopathology. Its use allows analysis of the entire lip, without excision. We reported the evaluation of 5 cases of CG based on clinical RCM and histopathological correlation. RCM examination of the lip vermilion mainly revealed a bright aspect of the superficial epithelial layers, which corresponded to labial keratosis. Alteration of the classical epithelial honeycomb pattern was observed in RCM, which corresponded to epithelial changes in actinic cheilitis at histopathology. Round, dark empty spaces intermingling the epithelium, corresponded to the ectopic excretory salivary gland ducts that open their ostia within the lip vermilion. In the lamina propria, the most striking feature was superficial salivary gland lobules, seen as dark gray lobular structures. Our study, demonstrated the use of RCM in the evaluation of CG, showing that a correlation between the clinical, digital RCM images and histopathology improved the diagnostic skills in CG evaluation.

  5. In vivo assessment of the structure of skin microcirculation by reflectance confocal-laser-scanning microscopy

    NASA Astrophysics Data System (ADS)

    Sugata, Keiichi; Osanai, Osamu; Kawada, Hiromitsu

    2012-02-01

    One of the major roles of the skin microcirculation is to supply oxygen and nutrition to the surrounding tissue. Regardless of the close relationship between the microcirculation and the surrounding tissue, there are few non-invasive methods that can evaluate both the microcirculation and its surrounding tissue at the same site. We visualized microcapillary plexus structures in human skin using in vivo reflectance confocal-laser-scanning microscopy (CLSM), Vivascope 3000® (Lucid Inc., USA) and Image J software (National Institutes of Health, USA) for video image processing. CLSM is a non-invasive technique that can visualize the internal structure of the skin at the cellular level. In addition to internal morphological information such as the extracellular matrix, our method reveals capillary structures up to the depth of the subpapillary plexus at the same site without the need for additional optical systems. Video images at specific depths of the inner forearm skin were recorded. By creating frame-to-frame difference images from the video images using off-line video image processing, we obtained images that emphasize the brightness depending on changes of intensity coming from the movement of blood cells. Merging images from different depths of the skin elucidates the 3-dimensional fine line-structure of the microcirculation. Overall our results show the feasibility of a non-invasive, high-resolution imaging technique to characterize the skin microcirculation and the surrounding tissue.

  6. A new wide field-of-view confocal imaging system and its applications in drug discovery and pathology

    NASA Astrophysics Data System (ADS)

    Li, Gang; Damaskinos, Savvas; Dixon, Arthur E.; Lee, Lucy E. J.

    2005-11-01

    Conventional widefield light microscopy and confocal scanning microscopy have been indispensable for pathology and drug discovery research. Clinical specimens from diseased tissues are examined, new drug candidates are tested on drug targets, and the morphological and molecular biological changes of cells and tissues are observed. High throughput screening of drug candidates requires highly efficient screening instruments. A standard biomedical slide is 1 by 3 inches (25.4 by 76.2 mm) in size. A typical tissue specimen is 10 mm in diameter. To form a high resolution image of the entire specimen, a conventional widefield light microscope must acquire a large number of small images of the specimen, and then tile them together, which is tedious, inefficient and error-prone. A patented new wide field-of-view confocal scanning laser imaging system has been developed for tissue imaging, which is capable of imaging an entire microscope slide without tiling. It is capable of operating in brightfield, reflection and epi-fluorescence imaging modes. Three (red, green and blue (RGB)) lasers are used to produce brightfield and reflection images, and to excite various fluorophores. This new confocal system makes examination of large biomedical specimens more efficient, and makes fluorescence examination of large specimens possible for the first time without tiling. Description of the new confocal technology and applications of the imaging system in pathology and drug discovery research, for example, imaging large tissue specimens, tissue microarrays, and zebrafish sections, are reported in this paper.

  7. Clinical usefulness of reflectance confocal microscopy in the management of facial lentigo maligna melanoma.

    PubMed

    Alarcón, I; Carrera, C; Puig, S; Malvehy, J

    2014-04-01

    Facial lentigo maligna melanoma can be a diagnostic challenge in daily clinical practice as it has similar clinical and morphological features to other lesions such as solar lentigines and pigmented actinic keratoses. Confocal microscopy is a noninvasive technique that provides real-time images of the epidermis and superficial dermis with cellular-level resolution. We describe 3 cases of suspected facial lentigo maligna that were assessed using dermoscopy and confocal microscopy before histopathology study. In the first case, diagnosed as lentigo maligna melanoma, presurgical mapping by confocal microscopy was performed to define the margins more accurately. In the second and third cases, with a clinical and dermoscopic suspicion of lentigo maligna melanoma, confocal microscopy was used to identify the optimal site for biopsy.

  8. Morphological characterization of solar lentigines by in vivo reflectance confocal microscopy: a longitudinal approach.

    PubMed

    Pollefliet, C; Corstjens, H; González, S; Hellemans, L; Declercq, L; Yarosh, D

    2013-04-01

    Solar lentigines are benign hyperpigmented skin lesions. Despite their widespread distribution, knowledge on the mechanisms of development is largely unknown. A clinical study was designed in which solar lentigines were characterized using various non-invasive clinical techniques. A subset of solar lentigines was followed over a 5-year time period. One hundred and twenty-eight solar lentigines were evaluated using in vivo reflectance confocal microscopy (RCM) for the evaluation of the length and density of their dermal papillae as well as the deformation of the alignment pattern of hyperrefractive basal cells. Skin colour, colour contrast, the size of the solar lentigo, epidermal proliferation rate, melanin and haemoglobin content were quantified. RCM imaging of solar lentigines revealed a profound structural deformation of the dermal papillae, as the alignment pattern of hyperrefractive basal cells shifted from a circle in non-lesional skin to an irregular non-circular shape in solar lentigines. There was a rise in the number of dermal papillae, and these dermal papillae were significantly longer. Solar lentigines had increased melanin and haemoglobin levels and a higher rate of epidermal proliferation. For a subset of nineteen solar lentigines, a longitudinal study was set-up in which these measurements were repeated 5 years after the first evaluation. The deformation and the number of the hyperrefractive dermal papillary rings increased significantly over the 5-year time span. The size of the lesion increased, and the skin colour became darker. RCM is a useful non-invasive clinical tool for the characterization of solar lentigines, in particular the compressive deformation of the dermal papillae. This deformation became more severe over a time period of 5 years. To our knowledge, this is the first time that the in vivo time-dependent progression of solar lentigines was supported by RCM images, contributing to an improved understanding of the formation and

  9. Fast intracellular motion in the living cell by video rate reflection confocal laser scanning microscopy

    PubMed Central

    VESELY, PAVEL; BOYDE, ALAN

    2001-01-01

    Fast intracellular motion (FIM) was first revealed by back scattered light (BSL) imaging in video rate confocal scanning laser microscopy (VRCSLM), beyond the limits of spatial and temporal resolution obtainable with conventional optical microscopy. BSL imaging enabled visualisation of intra and extracellular motion with resolution in space down to 0.2 μm and in time to 1/25th of a second. Mapping the cell space at 0.2 μm×0.2 μm (XY = in instantaneous best focal plane)×0.5 μm (Z = height/depth, optic axis direction) volume steps revealed a communication layer above the known contact layer and an integrated dynamic spatial network (IDSN) towards the cell centre. FIM was originally observed as localised quasichaotic dancing (dithering) or reflecting patches/spots in the cell centre, faster in the darker nuclear space. Later, a second type of FIM was recognised which differed by the presence of a varied proportion of centrifugal and centripetal directional movements and/or jumping of patches/spots in the cell centre and outside the nuclear space. The first type is characteristic for cells in slightly adverse conditions while the second type has so far only been found in eutrophic cells. Temporal speeding up and coarsening of FIM, followed by slowing and eventually cessation at cell death, was found on exposure to strong stressors. It was concluded that the state of FIM provides instantaneous information about individual cell reactions to actual treatment and about cell survival. A putative switch between the first and second type FIM could be considered as an indicator of timing of cellular processes. The significance of FIM for the biology of the cell is seen in the rapid assessment of the condition of an individual live cell investigated by combination of various methods. Requirements for further development of this approach are outlined. PMID:11465857

  10. Compressive sensing in reflectance confocal microscopy of skin images: a preliminary comparative study

    NASA Astrophysics Data System (ADS)

    Arias, Fernando X.; Sierra, Heidy; Rajadhyaksha, Milind; Arzuaga, Emmanuel

    2016-03-01

    Compressive Sensing (CS)-based technologies have shown potential to improve the efficiency of acquisition, manipulation, analysis and storage processes on signals and imagery with slight discernible loss in data performance. The CS framework relies on the reconstruction of signals that are presumed sparse in some domain, from a significantly small data collection of linear projections of the signal of interest. As a result, a solution to the underdetermined linear system resulting from this paradigm makes it possible to estimate the original signal with high accuracy. One common approach to solve the linear system is based on methods that minimize the L1-norm. Several fast algorithms have been developed for this purpose. This paper presents a study on the use of CS in high-resolution reflectance confocal microscopy (RCM) images of the skin. RCM offers a cell resolution level similar to that used in histology to identify cellular patterns for diagnosis of skin diseases. However, imaging of large areas (required for effective clinical evaluation) at such high-resolution can turn image capturing, processing and storage processes into a time consuming procedure, which may pose a limitation for use in clinical settings. We present an analysis on the compression ratio that may allow for a simpler capturing approach while reconstructing the required cellular resolution for clinical use. We provide a comparative study in compressive sensing and estimate its effectiveness in terms of compression ratio vs. image reconstruction accuracy. Preliminary results show that by using as little as 25% of the original number of samples, cellular resolution may be reconstructed with high accuracy.

  11. The invisible basal cell carcinoma: how reflectance confocal microscopy improves the diagnostic accuracy of clinically unclear facial macules and papules.

    PubMed

    Ruini, C; Hartmann, D; Saral, S; Krammer, S; Ruzicka, T; von Braunmühl, T

    2016-11-01

    Difficult to diagnose and early non-melanoma skin cancer lesions are frequently seen in daily clinical practice. Besides precancerous lesions such as actinic keratosis, basal cell carcinomas (BCCs) score the highest frequency in skin tumors. While infiltrative and nodular BCCs require a surgical treatment with a significant impact on the patients' quality of life, early and superficial BCCs might benefit from numerous conservative treatments, such as topical immune-modulators or photodynamic therapy. Dermoscopy has shown a high sensitivity and specificity in the diagnosis of early BCCs, and non-invasive imaging techniques like reflectance confocal microscopy (RCM) have proven to be helpful. The aim of our study was to investigate the importance of RCM in the diagnosis of BCCs with indistinct clinical and dermoscopic features. We retrospectively examined 27 histologically proven BCCs in which diagnosis was not possible based on naked eye examination; we separately reviewed clinical, dermoscopic, and confocal microscopy features and evaluated the lesions meeting the common diagnostic criteria for BCCs, and our diagnostic confidence. All lesions were clinically unclear, with no characteristic features suggestive for BCC; dermoscopy showed in most cases unspecific teleangiectasias (74 %) and micro-erosions (52 %). Confocal microscopy revealed in most of the cases the presence of specific criteria: peripheral palisading of the nuclei (89 %), clefting (70 %), stromal reaction (70 %), dark silhouettes (70 %), inflammatory particles (70 %), and tumor islands (67 %). In the absence of significant diagnostic clinical signs and with unclear dermoscopic features, specific confocal patterns were present in most of the lesions and enabled a correct diagnosis. In the absence of significant clinical features of BCC and in the case of uncertain dermoscopy, striking confocal features are detectable and easy to recognize in most cases. Confocal microscopy can therefore be

  12. Clinical applications of in vivo fluorescence confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Oh, Chilhwan; Park, Sangyong; Kim, Junhyung; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Chun, Byungseon; Gweon, Daegab

    2008-02-01

    Living skin for basic and clinical research can be evaluated by Confocal Laser Scanning Microscope (CLSM) non-invasively. CLSM imaging system can achieve skin image its native state either "in vivo" or "fresh biopsy (ex vivo)" without fixation, sectioning and staining that is necessary for routine histology. This study examines the potential fluorescent CLSM with a various exogenous fluorescent contrast agent, to provide with more resolution images in skin. In addition, in vivo fluorescent CLSM researchers will be extended a range of potential clinical application. The prototype of our CLSM system has been developed by Prof. Gweon's group. The operating parameters are composed of some units, such as illuminated wavelength 488 nm, argon illumination power up to 20mW on the skin, objective lens, 0.9NA oil immersion, axial resolution 1.0μm, field of view 200μm x 100μm (lateral resolution , 0.3μm). In human volunteer, fluorescein sodium was administrated topically and intradermally. Animal studies were done in GFP transgenic mouse, IRC mouse and pig skin. For imaging of animal skin, fluorescein sodium, acridine orange, and curcumine were used for fluorescein contrast agent. We also used the GFP transgenic mouse for fluorescein CLSM imaging. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. Acridin Orange can be highlight nuclei in viable keratinocyte. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, hair and eccrine gland. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. In

  13. Line-Scanning Reflectance Confocal Microscopy of Human Skin: Comparison of Full-pupil and Divided-pupil Configurations

    PubMed Central

    Gareau, Daniel S.; Abeytunge, Sanjee; Rajadhyaksha, Milind

    2009-01-01

    Line-scanning, with pupil engineering and the use of linear array detectors, may enable simple, small and low-cost confocal microscopes for clinical imaging of human epithelial tissues. However, a fundamental understanding of line-scanning performance within the highly scattering and aberrating conditions of human tissue is necessary, to translate from benchtop instrumentation to clinical implementation. The results of a preliminary investigation for reflectance imaging in skin are reported. PMID:19838284

  14. In vivo reflectance confocal microscopy of shave biopsy wounds: feasibility of intra-operative mapping of cancer margins

    PubMed Central

    Scope, A; Mahmood, U; Gareau, DS; Kenkre, M; Lieb, JA; Nehal, KS; Rajadhyaksha, M

    2010-01-01

    Background Reflectance confocal microscopy (RCM) images skin at cellular resolution and has shown utility for the diagnosis of nonmelanoma skin cancer in-vivo. Topical application of Aluminum Chloride (AlCl3) enhances contrast in RCM images by brightening nuclei. Objective To investigate feasibility of RCM imaging of shave biopsy wounds using AlCl3 as a contrast agent. Methods AlCl3 staining was optimized, in terms of concentration versus immersion time, on excised tissue ex-vivo. RCM imaging protocol was tested in patients undergoing shave biopsies. The RCM images were retrospectively analyzed and compared to the corresponding histopathology. Results For 35% AlCl3, routinely used for hemostasis in clinic, minimum immersion time was determined to be 1 minute. We identified 3 consistent patterns of margins on RCM mosaic images by varying depths: epidermal margins, peripheral dermal margins, and deep dermal margins. Tumour islands of basal cell carcinoma were identified at peripheral or deep dermal margins, correlating on histopathology with aggregates of neoplastic basaloid cells. Atypical cobblestone or honeycomb pattern were identified at the epidermal margins, correlating with a proliferation of atypical keratinocytes extending to biopsy margins. Conclusions RCM imaging of shave biopsy wounds is feasible and demonstrates the future possibility of intra-operative mapping in surgical wounds. PMID:20874785

  15. Concurrent Reflectance Confocal Microscopy and Laser Doppler Flowmetry to Improve Skin Cancer Imaging: A Monte Carlo Model and Experimental Validation

    PubMed Central

    Mowla, Alireza; Taimre, Thomas; Lim, Yah Leng; Bertling, Karl; Wilson, Stephen J.; Prow, Tarl W.; Soyer, H. Peter; Rakić, Aleksandar D.

    2016-01-01

    Optical interrogation of suspicious skin lesions is standard care in the management of skin cancer worldwide. Morphological and functional markers of malignancy are often combined to improve expert human diagnostic power. We propose the evaluation of the combination of two independent optical biomarkers of skin tumours concurrently. The morphological modality of reflectance confocal microscopy (RCM) is combined with the functional modality of laser Doppler flowmetry, which is capable of quantifying tissue perfusion. To realize the idea, we propose laser feedback interferometry as an implementation of RCM, which is able to detect the Doppler signal in addition to the confocal reflectance signal. Based on the proposed technique, we study numerical models of skin tissue incorporating two optical biomarkers of malignancy: (i) abnormal red blood cell velocities and concentrations and (ii) anomalous optical properties manifested through tissue confocal reflectance, using Monte Carlo simulation. We also conduct a laboratory experiment on a microfluidic channel containing a dynamic turbid medium, to validate the efficacy of the technique. We quantify the performance of the technique by examining a signal to background ratio (SBR) in both the numerical and experimental models, and it is shown that both simulated and experimental SBRs improve consistently using this technique. This work indicates the feasibility of an optical instrument, which may have a role in enhanced imaging of skin malignancies. PMID:27598157

  16. “Twin lesions”: Which one is the bad one? Improvement of clinical diagnosis with reflectance confocal microscopy

    PubMed Central

    Saral, Secil; Hartmann, Daniela; Letulè, Valerie; Ruzicka, Thomas; Ruini, Cristel; von Braunmühl, Tanja

    2017-01-01

    Background In vivo reflectance confocal microscopy (RCM) is a novel non-invasive diagnostic tool, which is used to differentiate skin lesions. Even in lesions with similar dermatoscopic images, RCM may improve diagnostic accuracy. Methods Three sets of false “twin lesions” with similar macroscopic and dermatoscopic images are matched. All lesions are evaluated with RCM and lesions are excised for further evaluation. Corresponding features in confocal images, dermatoscopy and histopathology are discussed. Results In all matched pairs, one of the lesions was diagnosed as melanoma with the observation of melanoma findings such as: epidermal disarray, pagetoid cells in epidermis and cellular atypia at the junction. Benign lesions were differentiated easily with RCM imaging. Conclusion Examining dermatoscopically difficult and/or similar lesions with RCM facilitates diagnostic and therapeutic decision making. Using RCM in daily practice may contribute to a decrease in unnecessary excisions. PMID:28243488

  17. A confocal video-rate laser-beam scanning reflected-light microscope with no moving parts.

    PubMed

    Goldstein, S R; Hubin, T; Rosenthal, S; Washburn, C

    1990-01-01

    A no-moving-parts, 30 frames/s, laser-beam scanning confocal reflected-light microscope has been developed. In principle, the technique can be extended to fluorescence and transmission light microscopy. Acousto-optic beam deflectors controlled by digital electronics move a laser beam in a 512-line interlaced 8.5 x 8.5-mm raster. The light passes through a beam splitter, enters an inverted microscope through the side camera port, and is imaged at the object by the microscope objective. Reflected light returns through the objective, exits the camera port, is reflected off the beam splitter, and is imaged on to the photocathode of an image dissector tube (IDT). Confocality is provided by raster scanning the IDT aperture coincident with the congruent image of the laser beam incident on the object. Real-time jitter-free reflected light images of a variety of biological objects have been produced. Computer-controlled alignment of the laser scan and IDT is performed in several seconds.

  18. Validation study of automated dermal/epidermal junction localization algorithm in reflectance confocal microscopy images of skin

    NASA Astrophysics Data System (ADS)

    Kurugol, Sila; Rajadhyaksha, Milind; Dy, Jennifer G.; Brooks, Dana H.

    2012-02-01

    Reflectance confocal microscopy (RCM) has seen increasing clinical application for noninvasive diagnosis of skin cancer. Identifying the location of the dermal-epidermal junction (DEJ) in the image stacks is key for effective clinical imaging. For example, one clinical imaging procedure acquires a dense stack of 0.5x0.5mm FOV images and then, after manual determination of DEJ depth, collects a 5x5mm mosaic at that depth for diagnosis. However, especially in lightly pigmented skin, RCM images have low contrast at the DEJ which makes repeatable, objective visual identification challenging. We have previously published proof of concept for an automated algorithm for DEJ detection in both highly- and lightly-pigmented skin types based on sequential feature segmentation and classification. In lightly-pigmented skin the change of skin texture with depth was detected by the algorithm and used to locate the DEJ. Here we report on further validation of our algorithm on a more extensive collection of 24 image stacks (15 fair skin, 9 dark skin). We compare algorithm performance against classification by three clinical experts. We also evaluate inter-expert consistency among the experts. The average correlation across experts was 0.81 for lightly pigmented skin, indicating the difficulty of the problem. The algorithm achieved epidermis/dermis misclassification rates smaller than 10% (based on 25x25 mm tiles) and average distance from the expert labeled boundaries of ~6.4 μm for fair skin and ~5.3 μm for dark skin, well within average cell size and less than 2x the instrument resolution in the optical axis.

  19. A simple method for overcoming some problems when observing thick reflective biological samples with a confocal scanning laser microscope.

    PubMed

    Rumio, C; Morini, M; Miani, A; Barajon, I; Castano, P

    1995-01-01

    A simple device is described, which allows the range of depth of scanning to be reduced when observing thick reflecting biological samples with a confocal scanning laser microscope (CSLM). Thick histological sections of human skin and rat brain stem were mounted between two coverslips ('sandwich' style) and the optical tomography was performed from both sides by turning the 'sandwich' upside-down. The samples were impregnated using standard Golgi-Cox, 'rapid Golgi' or other silver methods. The ability to turn the 'sandwich' upside-down is particularly useful when the reflective structure inspected is deep inside the section, i.e., near the lower surface of the specimen, or when it is opaque to the laser beam or excessively reflective.

  20. Combined reflectance confocal microscopy-optical coherence tomography for delineation of basal cell carcinoma margins: an ex vivo study

    PubMed Central

    Iftimia, Nicusor; Peterson, Gary; Chang, Ernest W.; Maguluri, Gopi; Fox, William; Rajadhyaksha, Milind

    2016-01-01

    Abstract. We present a combined reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) approach, integrated within a single optical layout, for diagnosis of basal cell carcinomas (BCCs) and delineation of margins. While RCM imaging detects BCC presence (diagnoses) and its lateral spreading (margins) with measured resolution of ∼1  μm, OCT imaging delineates BCC depth spreading (margins) with resolution of ∼7  μm. When delineating margins in 20 specimens of superficial and nodular BCCs, depth could be reliably determined down to ∼600  μm, and agreement with histology was within about ±50  μm. PMID:26780224

  1. Detection of living Sarcoptes scabiei larvae by reflectance mode confocal microscopy in the skin of a patient with crusted scabies

    NASA Astrophysics Data System (ADS)

    Levi, Assi; Mumcuoglu, Kosta Y.; Ingber, Arieh; Enk, Claes D.

    2012-06-01

    Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity reaction to infestation of the skin by the mite Sarcoptes scabiei. The diagnosis of scabies is established clinically and confirmed by identifying mites or eggs by microscopic examination of scrapings from the skin or by surface microscopy using a dermatoscope. Reflectance-mode confocal microscopy is a novel technique used for noninvasive imaging of skin structures and lesions at a resolution compatible to that of conventional histology. Recently, the technique was employed for the confirmation of the clinical diagnosis of scabies. We demonstrate the first ever documentation of a larva moving freely inside the skin of a patient infected with scabies.

  2. Combined reflectance confocal microscopy-optical coherence tomography for delineation of basal cell carcinoma margins: an ex vivo study

    NASA Astrophysics Data System (ADS)

    Iftimia, Nicusor; Peterson, Gary; Chang, Ernest W.; Maguluri, Gopi; Fox, William; Rajadhyaksha, Milind

    2016-01-01

    We present a combined reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) approach, integrated within a single optical layout, for diagnosis of basal cell carcinomas (BCCs) and delineation of margins. While RCM imaging detects BCC presence (diagnoses) and its lateral spreading (margins) with measured resolution of ˜1 μm, OCT imaging delineates BCC depth spreading (margins) with resolution of ˜7 μm. When delineating margins in 20 specimens of superficial and nodular BCCs, depth could be reliably determined down to ˜600 μm, and agreement with histology was within about ±50 μm.

  3. Confocal reflectance and two-photon microscopy studies of a songbird skull for preparation of transcranial imaging

    NASA Astrophysics Data System (ADS)

    Abi-Haidar, Darine; Oliver, Thomas

    2009-05-01

    We present experiments and analyses of confocal reflectance and two-photon microscopy studies of zebra finch skull samples. The thin and hollow structure of these birds' skulls is quite translucent, which can allow in vivo transcranial two-photon imaging for brain activation monitoring. However, the skull structure is also quite complex, with high refractive index changes on a macroscopic scale. These studies aim at exploring the geometrical and scattering properties of these skull samples with the use of several confocal microscopy contrasts. Moreover, the study of the axial reflectance exponential decay is used to estimate the scattering coefficients of the bone. Finally, two-photon imaging experiments of a fluorescent object located beneath the skull are carried out. It reveals that two-photon fluorescence can be collected through the skull with a strong signal. It also reveals that the spatial resolution loss is quite high and cannot be fully explained by the bulk scattering properties of the bone, but also by the presence of the high refractive index inhomogeneity of this pneumatic skull structure. Even if the optical properties of the skull are different during in vivo experiments, these preliminary studies are aimed at preparing and optimizing transcranial brain activation monitoring experiments on songbirds.

  4. Detectability of contrast agents for video-rate confocal reflectance microscopy of skin and microcirculation in vivo

    NASA Astrophysics Data System (ADS)

    Rajadhyaksha, Milind M.; Gonzalez, Salvador

    2003-06-01

    The lack of structure-specific contrast limits the usefulness of confocal reflectance microscopy to morphologic investigations at the cellular- and nuclear-level in human and animal skin in vivo. Morphologic and functional imaging at specific organelle- and ultrastructure-levels will require contrast agents that may be used and detected in vivo. High-resolution confocal reflectance imaging is based on the detection of singly back-scattered photons, where contrast is provided by variations in the refractive indices of microstructures. We carried out a quantitative Mie back-scatter analysis and imaging experiments to understand signal detectability of reflectance contrast agents for visualizing human skin and animal microcirculation. When imaging at video-rate with illumination of 10 milliwatts at 1064 nm, we detect 100-104 photons/pixel from the epidermis to dermis, relative to a background of 100 photons; this provides a signal-to-noise ratio of 3-40 and signal-to-background of 1-100. Organelles of size (d) 0.1-1.0 μm with refractive indices (n) of 1.34-1.45 (relative to n=1.34 for epidermis, n=1.38 for dermis) back-scatter 10-104 photons/pixel. Exogenous contrast agents such as liposomes (n=1.41, d=0.7 μm) and polystyrene microspheres (d=0.2-1.0 μm, n=1.57; 100-105 photons/pixel) are detectable and they strongly enhance the contrast of microcirculation in the dermis of Sprague-Dawley rats. Topically applied 5% acetic acid causes the intra-nuclear 30-100 nm-thin chromatin filaments to condense into 1-5 μm-thick strands, increasing back-scattered signal from 100 to 104 photons/pixels, making the nuclei appear bright and easily detectable in basal cell cancers. Such analyses provide a basis for optimizing confocal microscope design for detectability of contrast agents in vivo.

  5. Analysis of the efficiency of hair removal by different optical methods: comparison of Trichoscan, reflectance confocal microscopy, and optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Kuck, Monika; Schanzer, Sabine; Ulrich, Martina; Bartels, Natalie Garcia; Meinke, Martina C.; Fluhr, Joachim; Krah, Martin; Blume-Peytavi, Ulrike; Stockfleth, Eggert; Lademann, Jürgen

    2012-10-01

    Noninvasive diagnostic tools, such as Trichoscan, reflectance confocal microscopy (RCM), and optical coherence tomography (OCT), are efficient methods of hair shaft and growth evaluation. The aim of this study was to carry out a comparative assessment of these three medical procedures by measuring the hair shaft and hair growth after hair removal for a defined period of five days. The application of these techniques was demonstrated by measuring hair growth on the lower leg of six female volunteers. After removal of the hair shaft with a shaving system, the hair follicle infundibula and the length of the growing hairs were measured with the Trichoscan, RCM, and OCT method. All three methods are reliable hair measuring tools after hair removal. Trichoscan is best suited in the implementation of hair growth measurement and RCM in the analysis of hair follicles, whereas the OCT system can be consulted as an additional measurement for the evaluation of the hair follicle and length.

  6. In vivo confocal microscopy in dermatology: from research to clinical application

    NASA Astrophysics Data System (ADS)

    Ulrich, Martina; Lange-Asschenfeldt, Susanne

    2013-06-01

    Confocal laser scanning microscopy (CLSM) represents an emerging technique for the noninvasive histomorphological analysis of skin in vivo and has shown its applicability for dermatological research as well as its value as an adjunct tool in the clinical management of skin cancer patients. Herein, we aim to give an overview on the current clinical indications for CLSM in dermatology and also highlight the diverse applications of CLSM in dermatological research.

  7. Combined analysis of in situ hybridization, cell cycle and structural markers using reflectance and immunofluorescence confocal microscopy.

    PubMed

    Linares-Cruz, G; Millot, G; De Cremoux, P; Vassy, J; Olofsson, B; Rigaut, J P; Calvo, F

    1995-01-01

    A method for the simultaneous detection of mRNA by reflectance in situ hybridization (RISH), cell cycle and structural markers by immunofluorescence using confocal laser scanning microscopy is presented. The mRNA expression of two ras-related genes rhoB and rhoC was analysed in human breast cancer cell lines and human histological specimens (breast cancer tissues and skin biopsies). In breast cancer cell lines, the conditions were optimized to detect RNA-RNA hybrids and DNA synthesis after pulse-labelling with bromodeoxyuridine. Endonuclease-exonuclease digestion, which allows the accessibility to specific antibodies of halogenated pyrimidine molecules, was carried out following ISH. Finally, cytokeratin or vimentin staining was performed. The detection of signals, arising from 1-nm colloidal gold particles without silver enhancement, by reflectance confocal laser scanning microscopy is described. Bromodeoxybiridine DNA markers and cytokeratin/vimentin staining were detected concomitantly using different fluorochromes. To allow comparative expression of two related genes, the mRNA of rhoB and rhoC were detected using digoxigenin- or biotin-labelled riboprobes and, after 3-D imaging, a detailed analysis by optical horizontal (x, y) and vertical (x, z) sectioning was undertaken. The subsequent bromodeoxyuridine detection procedure permitted to us explore the specific transcription of these two genes during S and non-S phases. This method allows the identification and localization of several subcellular components in cells within a complex tissue structure and makes it possible to analyse further transcript localization in relation to the function of the encoded protein and to the cell cycle.

  8. Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy.

    PubMed

    Nakao, Madoka; Yoshida, Shigeto; Tanaka, Shinji; Takemura, Yoshito; Oka, Shiro; Yoshihara, Masaharu; Chayama, Kazuaki

    2008-01-01

    Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compare prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. 20 sites in the esophagus and 40 sites in the stomach are examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan) is used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei are visualized. In nine of the ten normal esophageal mucosa, cell membranes are visualized, and in five of the ten esophageal cancers, cell membranes are visualized. In all normal gastric mucosa, nuclei and cell membranes are not visualized, but in ten of the 20 gastric cancers, nuclei are visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy.

  9. Video rate confocal laser scanning reflection microscopy in the investigation of normal and neoplastic living cell dynamics.

    PubMed

    Vesely, P; Boyde, A

    1996-01-01

    The introduction of video rate confocal laser scanning microscopes (VRCLSM) used in reflection mode with high magnification, high aperture objective lenses and with further magnification by a zoom facility allowed the first detailed observations of the activity of living cytoplasm and offered a new tool for investigation of the structural transition from the living state to the specimen fixed for electron microscopy (EM). We used a Noran Odyssey VRCLSM in reflection (backscattered) mode. A greater degree of oversampling and more comfortable viewing of the liver or taped video image was achieved at zoom factor 5, giving a display monitor field width of 10 microns. A series of mesenchyme derived cell lines--from normal cells to sarcoma cells of different malignancy--was used to compare behaviour of the observed intracellular structures and results of fixation. We contrasted the dynamic behaviour of fine features in the cytoplasm of normal and neoplastic living cells and changes induced by various treatments. The tubulomembraneous 3D structure of cytoplasm in living cells is dynamic with motion observable at the new limits of resolution provided by VRCLSM. All organelles appear integrated into one functional compartment supporting the continuous 3D trafficking of small particles (vesicles). This integrated dynamic spatial network (IDSN) was found to be largest in neoplastic cells.

  10. A novel technique using potassium permanganate and reflectance confocal microscopy to image biofilm extracellular polymeric matrix reveals non-eDNA networks in Pseudomonas aeruginosa biofilms

    PubMed Central

    Swearingen, Matthew C.; Mehta, Ajeet; Mehta, Amar; Nistico, Laura; Hill, Preston J.; Falzarano, Anthony R.; Wozniak, Daniel J.; Hall-Stoodley, Luanne; Stoodley, Paul

    2015-01-01

    Biofilms are etiologically important in the development of chronic medical and dental infections. The biofilm extracellular polymeric substance (EPS) determines biofilm structure and allows bacteria in biofilms to adapt to changes in mechanical loads such as fluid shear. However, EPS components are difficult to visualize microscopically because of their low density and molecular complexity. Here, we tested potassium permanganate, KMnO4, for use as a non-specific EPS contrast-enhancing stain using confocal laser scanning microscopy in reflectance mode. We demonstrate that KMnO4 reacted with EPS components of various strains of Pseudomonas, Staphylococcus and Streptococcus, yielding brown MnO2 precipitate deposition on the EPS, which was quantifiable using data from the laser reflection detector. Furthermore, the MnO2 signal could be quantified in combination with fluorescent nucleic acid staining. COMSTAT image analysis indicated that KMnO4 staining increased the estimated biovolume over that determined by nucleic acid staining alone for all strains tested, and revealed non-eDNA EPS networks in Pseudomonas aeruginosa biofilm. In vitro and in vivo testing indicated that KMnO4 reacted with poly-N-acetylglucosamine and Pseudomonas Pel polysaccharide, but did not react strongly with DNA or alginate. KMnO4 staining may have application as a research tool and for diagnostic potential for biofilms in clinical samples. PMID:26536894

  11. A novel technique using potassium permanganate and reflectance confocal microscopy to image biofilm extracellular polymeric matrix reveals non-eDNA networks in Pseudomonas aeruginosa biofilms.

    PubMed

    Swearingen, Matthew C; Mehta, Ajeet; Mehta, Amar; Nistico, Laura; Hill, Preston J; Falzarano, Anthony R; Wozniak, Daniel J; Hall-Stoodley, Luanne; Stoodley, Paul

    2016-02-01

    Biofilms are etiologically important in the development of chronic medical and dental infections. The biofilm extracellular polymeric substance (EPS) determines biofilm structure and allows bacteria in biofilms to adapt to changes in mechanical loads such as fluid shear. However, EPS components are difficult to visualize microscopically because of their low density and molecular complexity. Here, we tested potassium permanganate, KMnO4, for use as a non-specific EPS contrast-enhancing stain using confocal laser scanning microscopy in reflectance mode. We demonstrate that KMnO4 reacted with EPS components of various strains of Pseudomonas, Staphylococcus and Streptococcus, yielding brown MnO2 precipitate deposition on the EPS, which was quantifiable using data from the laser reflection detector. Furthermore, the MnO2 signal could be quantified in combination with fluorescent nucleic acid staining. COMSTAT image analysis indicated that KMnO4 staining increased the estimated biovolume over that determined by nucleic acid staining alone for all strains tested, and revealed non-eDNA EPS networks in Pseudomonas aeruginosa biofilm. In vitro and in vivo testing indicated that KMnO4 reacted with poly-N-acetylglucosamine and Pseudomonas Pel polysaccharide, but did not react strongly with DNA or alginate. KMnO4 staining may have application as a research tool and for diagnostic potential for biofilms in clinical samples.

  12. Pilot study of semiautomated localization of the dermal/epidermal junction in reflectance confocal microscopy images of skin

    NASA Astrophysics Data System (ADS)

    Kurugol, Sila; Dy, Jennifer G.; Brooks, Dana H.; Rajadhyaksha, Milind

    2011-03-01

    Reflectance confocal microscopy (RCM) continues to be translated toward the detection of skin cancers in vivo. Automated image analysis may help clinicians and accelerate clinical acceptance of RCM. For screening and diagnosis of cancer, the dermal/epidermal junction (DEJ), at which melanomas and basal cell carcinomas originate, is an important feature in skin. In RCM images, the DEJ is marked by optically subtle changes and features and is difficult to detect purely by visual examination. Challenges for automation of DEJ detection include heterogeneity of skin tissue, high inter-, intra-subject variability, and low optical contrast. To cope with these challenges, we propose a semiautomated hybrid sequence segmentation/classification algorithm that partitions z-stacks of tiles into homogeneous segments by fitting a model of skin layer dynamics and then classifies tile segments as epidermis, dermis, or transitional DEJ region using texture features. We evaluate two different training scenarios: 1. training and testing on portions of the same stack; 2. training on one labeled stack and testing on one from a different subject with similar skin type. Initial results demonstrate the detectability of the DEJ in both scenarios with epidermis/dermis misclassification rates smaller than 10% and average distance from the expert labeled boundaries around 8.5 μm.

  13. Reflectance confocal microscopy and dermoscopy for in vivo, non-invasive skin imaging of superficial basal cell carcinoma

    PubMed Central

    GHITA, MIHAELA A.; CARUNTU, CONSTANTIN; ROSCA, ADRIAN E.; KALESHI, HARILLAQ; CARUNTU, ANA; MORARU, LILIANA; DOCEA, ANCA OANA; ZURAC, SABINA; BODA, DANIEL; NEAGU, MONICA; SPANDIDOS, DEMETRIOS A.; TSATSAKIS, ARISTIDIS M.

    2016-01-01

    Superficial basal cell carcinoma (sBCC) is the second most frequent histological type of basal cell carcinoma (BCC), usually requiring a skin biopsy to confirm the diagnosis. It usually appears on the upper trunk and shoulders as erythematous and squamous lesions. Although it has a slow growth and seldom metastasizes, early diagnosis and management are of crucial importance in preventing local invasion and subsequent disfigurement. Dermoscopy is nowadays an indispensable tool for the dermatologist when evaluating skin tumors. Reflectance confocal microscopy (RCM) is a novel imaging technique that allows the non-invasive, in vivo quasi-microscopic morphological and dynamic assessment of superficial skin tumors. Moreover, it offers the advantage of performing infinite repeatable determinations to monitor disease progression and non-surgical treatment for sBCC. Herein, we present three lesions of sBCC evaluated using in vivo and non-invasive imaging techniques, emphasizing the usefulness of combining RCM with dermoscopy for increasing the diagnostic accuracy of sBCC. PMID:27123056

  14. In vivo detection of basal cell carcinoma: comparison of a reflectance confocal microscope and a multiphoton tomograph.

    PubMed

    Ulrich, Martina; Klemp, Marisa; Darvin, Maxim E; König, Karsten; Lademann, Jürgen; Meinke, Martina C

    2013-06-01

    The standard diagnostic procedure for basal cell carcinoma (BCC) is invasive tissue biopsy with time-consuming histological examination. To reduce the number of biopsies, noninvasive optical methods have been developed providing high-resolution skin examination. We present direct comparison of a reflectance confocal microscope (RLSM) and a multiphoton tomograph (MPT) for BCC diagnosis. Both systems are applied to nine patients prior to surgery, and the results are analyzed, including histological results. Both systems prove suitable for detecting typical characteristics of BCC in various stages. The RLSM allows large horizontal overview images to be obtained, enabling the investigator to find the regions of interest quickly, e.g., BCC nests. Elongated cells and palisading structures are easily recognized using both methods. Due to the higher resolution, changes in nucleus diameter or cytoplasm could be visualized with the MPT. Therefore, the nucleus diameter, nucleus/cytoplasm ratio, and cell density are estimated for normal and BCC cells using the MPT. The nucleus of elongated BCC cells is significantly longer than other measured normal skin cells, whereas the cell density and nucleus/cytoplasm ratio of BCC cannot be significantly distinguished from granular cells.

  15. In vivo detection of basal cell carcinoma: comparison of a reflectance confocal microscope and a multiphoton tomograph

    NASA Astrophysics Data System (ADS)

    Ulrich, Martina; Klemp, Marisa; Darvin, Maxim E.; König, Karsten; Lademann, Jürgen; Meinke, Martina C.

    2013-06-01

    The standard diagnostic procedure for basal cell carcinoma (BCC) is invasive tissue biopsy with time-consuming histological examination. To reduce the number of biopsies, noninvasive optical methods have been developed providing high-resolution skin examination. We present direct comparison of a reflectance confocal microscope (RLSM) and a multiphoton tomograph (MPT) for BCC diagnosis. Both systems are applied to nine patients prior to surgery, and the results are analyzed, including histological results. Both systems prove suitable for detecting typical characteristics of BCC in various stages. The RLSM allows large horizontal overview images to be obtained, enabling the investigator to find the regions of interest quickly, e.g., BCC nests. Elongated cells and palisading structures are easily recognized using both methods. Due to the higher resolution, changes in nucleus diameter or cytoplasm could be visualized with the MPT. Therefore, the nucleus diameter, nucleus/cytoplasm ratio, and cell density are estimated for normal and BCC cells using the MPT. The nucleus of elongated BCC cells is significantly longer than other measured normal skin cells, whereas the cell density and nucleus/cytoplasm ratio of BCC cannot be significantly distinguished from granular cells.

  16. Application of chromatic confocal displacement sensor in measurement of tip clearance

    NASA Astrophysics Data System (ADS)

    Bi, Chao; Li, Di; Fang, Jianguo; Zhang, Bin

    2016-10-01

    In the field of aeronautics, the tip clearance of rotor exerts a crucial influence on the performance of the aero engine. As defined as the radial distance between the top of the blade and the inner wall of the casing, the tip clearance of too large or small size will adversely affect the normal running of the engine. In order to realize accurate measurement of the tip clearance in a simple way, a non-contact measuring method by the chromatic confocal displacement sensor is proposed in the paper. The sensor possesses the advantages such as small volume, good signal-to-noise ratio, high accuracy and response frequency etc., which make it be widely used in engineering and industry. For testing the performance and potential application of the sensor, a simulation testing platform is established. In the platform, a simulation blisk is installed on the air bearing spindle and a chromatic confocal displacement sensor is fixed on the platform to measure the displacement variation of the blade tip, which can be used to characterize the variation of the tip clearance. In the simulation experiments, both of single and continuous measurement of the tip clearance of the 36 blades on the blisk is executed. As the results of experiments show, the chromatic confocal displacement sensor can meet the requirements of measuring task, in which both of high measuring efficiency and accuracy could be achieved. Therefore, the measuring method proposed in the paper can be utilized in the actual assembling sites of the aero engine.

  17. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model.

    PubMed

    Guilbert, Marie; Roig, Blandine; Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-02-23

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models.

  18. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model

    PubMed Central

    Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D.; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-01-01

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models. PMID:26885896

  19. Imaging In focus: Reflected light imaging: Techniques and applications.

    PubMed

    Guggenheim, Emily J; Lynch, Iseult; Rappoport, Joshua Z

    2017-02-01

    Reflectance imaging is a broad term that describes the formation of images by the detection of illumination light that is back-scattered from reflective features within a sample. Reflectance imaging can be performed in a variety of different configurations, such as confocal, oblique angle illumination, structured illumination, interferometry and total internal reflectance, permitting a plethora of biomedical applications. Reflectance imaging has proven indispensable for critical investigations into the safety and understanding of biomedically and environmentally relevant nano-materials, an area of high priority and investment. The non-destructive in vivo imaging ability of reflectance techniques permits alternative diagnostic strategies that may eventually facilitate the eradication of some invasive biopsy procedures. Reflectance can also provide additional structural information and clarity necessary in fluorescent based in vivo studies. Near-coverslip interrogation techniques, such as reflectance interferometry and total internal reflection, have provided a label free means to investigate cell-surface contacts, cell motility and vesicle trafficking in vivo and in vitro. Other key advances include the ability to acquire superresolution reflectance images providing increased spatial resolution.

  20. Overview of confocal microscopy.

    PubMed

    Swaim, William D

    2010-01-01

    Born out of the need to overcome an imaging problem in the 1950s, confocal microscopes today allow researchers to go beyond simple imaging and ask biochemical questions. This chapter provides background information on the development of modern confocal microscopes, their uses and applications. Sample preparation and observation are also discussed. Information is also provided about more advanced applications such as FRAP, FRET and 2-photon imaging. The requirements for setting up a confocal laboratory and the instrumentation needs are also discussed.

  1. Evaluation of the therapeutic results of actinic keratosis treated with topical 5% fluorouracil by reflectance confocal laser microscopy: preliminary study*

    PubMed Central

    Ishioka, Priscila; Maia, Marcus; Rodrigues, Sarita Bartholomei; Marta, Alessandra Cristina; Hirata, Sérgio Henrique

    2015-01-01

    Topical treatment for actinic keratosis with 5% fluorouracil has a recurrence rate of 54% in 12 months of follow-up. This study analyzed thirteen actinic keratoses on the upper limbs through confocal microscopy, at the time of clinical diagnosis and after 4 weeks of treatment with fluorouracil. After the treatment was established and evidence of clinical cure was achieved, in two of the nine actinic keratoses, confocal microscopy enabled visualization of focal areas of atypical honeycomb pattern in the epidermis indicating therapeutic failure. Preliminary data suggest the use of confocal microscopy as a tool for diagnosis and therapeutic control of actinic keratosis. PMID:26131881

  2. Quantification of Confocal Images Using LabVIEW for Tissue Engineering Applications.

    PubMed

    Sfakis, Lauren; Kamaldinov, Tim; Larsen, Melinda; Castracane, James; Khmaladze, Alexander

    2016-11-01

    Quantifying confocal images to enable location of specific proteins of interest in three-dimensional (3D) is important for many tissue engineering (TE) applications. Quantification of protein localization is essential for evaluation of specific scaffold constructs for cell growth and differentiation for application in TE and tissue regeneration strategies. Although obtaining information regarding protein expression levels is important, the location of proteins within cells grown on scaffolds is often the key to evaluating scaffold efficacy. Functional epithelial cell monolayers must be organized with apicobasal polarity with proteins specifically localized to the apical or basolateral regions of cells in many organs. In this work, a customized program was developed using the LabVIEW platform to quantify protein positions in Z-stacks of confocal images of epithelial cell monolayers. The program's functionality is demonstrated through salivary gland TE, since functional salivary epithelial cells must correctly orient many proteins on the apical and basolateral membranes. Bio-LabVIEW Image Matrix Evaluation (Bio-LIME) takes 3D information collected from confocal Z-stack images and processes the fluorescence at each pixel to determine cell heights, nuclei heights, nuclei widths, protein localization, and cell count. As a demonstration of its utility, Bio-LIME was used to quantify the 3D location of the Zonula occludens-1 protein contained within tight junctions and its change in 3D position in response to chemical modification of the scaffold with laminin. Additionally, Bio-LIME was used to demonstrate that there is no advantage of sub-100 nm poly lactic-co-glycolic acid nanofibers over 250 nm fibers for epithelial apicobasal polarization. Bio-LIME will be broadly applicable for quantification of proteins in 3D that are grown in many different contexts.

  3. In vivo reflectance-mode confocal microscopy assessments: impact of overweight on human skin microcirculation and histomorphology

    NASA Astrophysics Data System (ADS)

    Altintas, Ahmet A.; Aust, Matthias C.; Krämer, Robert; Vogt, Peter M.; Altintas, Mehmet A.

    2016-03-01

    Reflectance-mode confocal microscopy (RCM) enables in vivo assessment of the human skin. Impact of overweight on both human skin microcirculation and histomorphology has not been investigated in vivo. The purpose of this study is to evaluate both microcirculation and histomorphology in vivo in overweight. In 10 normotensive overweight nondiabetic individuals (OW-group, BMI 29.1±2.7 kg/m2) and 10 age- and sex-matched healthy lean controls (CO-group, BMI 20.4±1.9 kg/m2) the following parameters were evaluated using RCM: dermal blood cell flow (DBCF), density of dermal capillaries (DDC), epidermal thickness (ET), and epidermal cell size (ECS). DBCF was counted at 63.11±4.14 cells/min in OW-group and at 51.06±3.84 cells/min in CO-group (P<0.05). DDC was reduced in OW-group (4.91±0.39 capillaries/mm2) compared to the controls (6.02±0.64 capillaries/mm2, P<0.05). Histometric evaluation of ET reveals thickening in OW-group compared to the CO-group (54.79±4.25 μm versus 44.03±3.11 μm, P<0.05). ECS differed significantly (P<0.05) in OW-group (821.3±42.02 μm2) compared to the controls (772.6±34.79 μm2). Inverse correlation of dermal capillary density and overweight point to reduced total tissue perfusion while positive related blood cell flow reveals vasodilatation. Increase of both ET and cell size indicates remodeling of cutaneous histomorphology, maybe as an early stage of adiposity-related skin condition.

  4. Diagnosis of Basal Cell Carcinoma by Reflectance Confocal Microscopy: Study Design and Protocol of a Randomized Controlled Multicenter Trial

    PubMed Central

    Alkemade, Hans A.C; Maessen-Visch, Birgitte; Hendriks, Jan C.M; van Erp, Piet E.J; Adang, Eddy M.M; Gerritsen, Marie-Jeanne P

    2016-01-01

    Background Skin cancer, including basal cell carcinoma (BCC), has become a major health care problem. The limitations of a punch biopsy (at present the gold standard) as diagnostic method together with the increasing incidence of skin cancer point out the need for more accurate, cost-effective, and patient friendly diagnostic tools. In vivo reflectance confocal microscopy (RCM) is a noninvasive imaging technique that has great potential for skin cancer diagnosis. Objective To investigate whether in vivo RCM can correctly identify the subtype of BCC and to determine the cost-effectiveness of RCM compared with punch biopsy (usual care). Study design: Randomized controlled multicenter trial. Methods On the basis of 80% power and an alpha of 0.05, 329 patients with lesions clinically suspicious for BCC will be included in this study. Patients will be randomized for RCM or for a punch biopsy (usual care). When a BCC is diagnosed, surgical excision will follow and a follow-up visit will be planned 3 months later. Several questionnaires will be filled in (EQ-5D, EQ-5D VAS, iMTA PCQ, and TSQM-9). We will perform statistical analysis, cost-effectiveness, and patient outcome analysis after data collection. Results This research started in January 2016 and is ethically approved. We expect to finish this study at the end of 2018. Conclusions In this study, we will investigate whether RCM is at least as good in identifying BCC subtypes as conventional pathological investigation of skin biopsies. Anticipating that RCM is found to be a cost-effective alternative, it saves on direct medical consumption like labor of the pathologist and other medical personnel as well as materials related to treatment failure with at least equal effectiveness. Trial Registration Clinicaltrials.gov NCT02623101; https://clinicaltrials.gov/ct2/show/NCT02623101 (Archived by WebCite at http://www.webcitation.org/6id54WQa2) PMID:27363577

  5. An unsupervised machine learning method for delineating stratum corneum in reflectance confocal microscopy stacks of human skin in vivo

    NASA Astrophysics Data System (ADS)

    Bozkurt, Alican; Kose, Kivanc; Fox, Christi A.; Dy, Jennifer; Brooks, Dana H.; Rajadhyaksha, Milind

    2016-02-01

    Study of the stratum corneum (SC) in human skin is important for research in barrier structure and function, drug delivery, and water permeability of skin. The optical sectioning and high resolution of reflectance confocal microscopy (RCM) allows visual examination of SC non-invasively. Here, we present an unsupervised segmentation algorithm that can automatically delineate thickness of the SC in RCM images of human skin in-vivo. We mimic clinicians visual process by applying complex wavelet transform over non-overlapping local regions of size 16 x 16 μm called tiles, and analyze the textural changes in between consecutive tiles in axial (depth) direction. We use dual-tree complex wavelet transform to represent textural structures in each tile. This transform is almost shift-invariant, and directionally selective, which makes it highly efficient in texture representation. Using DT-CWT, we decompose each tile into 6 directional sub-bands with orientations in +/-15, 45, and 75 degrees and a low-pass band, which is the decimated version of the input. We apply 3 scales of decomposition by recursively transforming the low-pass bands and obtain 18 bands of different directionality at different scales. We then calculate mean and variance of each band resulting in a feature vector of 36 entries. Feature vectors obtained for each stack of tiles in axial direction are then clustered using spectral clustering in order to detect the textural changes in depth direction. Testing on a set of 15 RCM stacks produced a mean error of 5.45+/-1.32 μm, compared to the "ground truth" segmentation provided by a clinical expert reader.

  6. Semi-automated algorithm for localization of dermal/epidermal junction in reflectance confocal microscopy images of human skin

    NASA Astrophysics Data System (ADS)

    Kurugol, Sila; Dy, Jennifer G.; Rajadhyaksha, Milind; Gossage, Kirk W.; Weissmann, Jesse; Brooks, Dana H.

    2011-03-01

    The examination of the dermis/epidermis junction (DEJ) is clinically important for skin cancer diagnosis. Reflectance confocal microscopy (RCM) is an emerging tool for detection of skin cancers in vivo. However, visual localization of the DEJ in RCM images, with high accuracy and repeatability, is challenging, especially in fair skin, due to low contrast, heterogeneous structure and high inter- and intra-subject variability. We recently proposed a semi-automated algorithm to localize the DEJ in z-stacks of RCM images of fair skin, based on feature segmentation and classification. Here we extend the algorithm to dark skin. The extended algorithm first decides the skin type and then applies the appropriate DEJ localization method. In dark skin, strong backscatter from the pigment melanin causes the basal cells above the DEJ to appear with high contrast. To locate those high contrast regions, the algorithm operates on small tiles (regions) and finds the peaks of the smoothed average intensity depth profile of each tile. However, for some tiles, due to heterogeneity, multiple peaks in the depth profile exist and the strongest peak might not be the basal layer peak. To select the correct peak, basal cells are represented with a vector of texture features. The peak with most similar features to this feature vector is selected. The results show that the algorithm detected the skin types correctly for all 17 stacks tested (8 fair, 9 dark). The DEJ detection algorithm achieved an average distance from the ground truth DEJ surface of around 4.7μm for dark skin and around 7-14μm for fair skin.

  7. Application of confocal X-ray fluorescence micro-spectroscopy to the investigation of paint layers.

    PubMed

    Sun, Tianxi; Liu, Zhiguo; Wang, Guangfu; Ma, Yongzhong; Peng, Song; Sun, Weiyuan; Li, Fangzuo; Sun, Xuepeng; Ding, Xunliang

    2014-12-01

    A confocal micro X-ray fluorescence (MXRF) spectrometer based on polycapillary X-ray optics was used for the identification of paint layers. The performance of the confocal MXRF was studied. Multilayered paint fragments of a car were analyzed nondestructively to demonstrate that this confocal MXRF instrument could be used in the discrimination of the various layers in multilayer paint systems.

  8. Analysis of the efficiency of hair removal by different optical methods: comparison of Trichoscan, reflectance confocal microscopy, and optical coherence tomography.

    PubMed

    Kuck, Monika; Schanzer, Sabine; Ulrich, Martina; Garcia Bartels, Natalie; Meinke, Martina C; Fluhr, Joachim; Krah, Martin; Blume-Peytavi, Ulrike; Stockfleth, Eggert; Lademann, Jürgen

    2012-10-01

    Noninvasive diagnostic tools, such as Trichoscan®, reflectance confocal microscopy (RCM), and optical coherence tomography (OCT), are efficient methods of hair shaft and growth evaluation. The aim of this study was to carry out a comparative assessment of these three medical procedures by measuring the hair shaft and hair growth after hair removal for a defined period of five days. The application of these techniques was demonstrated by measuring hair growth on the lower leg of six female volunteers. After removal of the hair shaft with a shaving system, the hair follicle infundibula and the length of the growing hairs were measured with the Trichoscan®, RCM, and OCT method. All three methods are reliable hair measuring tools after hair removal. Trichoscan® is best suited in the implementation of hair growth measurement and RCM in the analysis of hair follicles, whereas the OCT system can be consulted as an additional measurement for the evaluation of the hair follicle and length.

  9. Pharmaceutical applications of confocal laser scanning microscopy: the physical characterisation of pharmaceutical systems.

    PubMed

    Pygall, Samuel R; Whetstone, Joanne; Timmins, Peter; Melia, Colin D

    2007-12-10

    The application of confocal laser scanning microscopy (CLSM) to the physicochemical characterisation of pharmaceutical systems is not as widespread as its application within the field of cell biology. However, methods have been developed to exploit the imaging capabilities of CLSM to study a wide range of pharmaceutical systems, including phase-separated polymers, colloidal systems, microspheres, pellets, tablets, film coatings, hydrophilic matrices, and chromatographic stationary phases. Additionally, methods to measure diffusion in gels, bioadhesives, and for monitoring microenvironmental pH change within dosage forms have been utilised. CLSM has also been used in the study of the physical interaction of dosage forms with biological barriers such as the eye, skin and intestinal epithelia, and in particular, to determine the effectiveness of a plethora of pharmaceutical systems to deliver drugs through these barriers. In the future, there is continuing scope for wider exploitation of existing techniques, and continuing advancements in instrumentation.

  10. Reflective coatings for solar applications

    SciTech Connect

    Jorgensen, G.

    1993-05-01

    Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals, it is desirable to maintain and increase the involvement of industrial organizations in reflective materials R D related to the conversion of solar resources to useful energy. Toward this end, NREL has recently initiated several collaborative efforts with industry to develop advanced reflector materials.

  11. Reflective coatings for solar applications

    SciTech Connect

    Jorgensen, G.

    1993-05-01

    Many applications of solar energy require large mirrors to provide high levels of concentrated sunlight. The success of such conversion systems hinges on the optical durability and economic viability of the reflector materials. A major effort at the National Renewable Energy Laboratory (NREL) has been to improve the existing reflector materials technology and to identify candidates that retain optical performance and durability criteria and offer potential for reduced cost. To attain the goals, it is desirable to maintain and increase the involvement of industrial organizations in reflective materials R&D related to the conversion of solar resources to useful energy. Toward this end, NREL has recently initiated several collaborative efforts with industry to develop advanced reflector materials.

  12. Image restoration for confocal microscopy: improving the limits of deconvolution, with application to the visualization of the mammalian hearing organ.

    PubMed Central

    Boutet de Monvel, J; Le Calvez, S; Ulfendahl, M

    2001-01-01

    Deconvolution algorithms have proven very effective in conventional (wide-field) fluorescence microscopy. Their application to confocal microscopy is hampered, in biological experiments, by the presence of important levels of noise in the images and by the lack of a precise knowledge of the point spread function (PSF) of the system. We investigate the application of wavelet-based processing tools to deal with these problems, in particular wavelet denoising methods, which turn out to be very effective in application to three-dimensional confocal images. When used in combination with more classical deconvolution algorithms, these methods provide a robust and efficient restoration scheme allowing one to deal with difficult imaging conditions. To make our approach applicable in practical situations, we measured the PSF of a Biorad-MRC1024 confocal microscope under a large set of imaging conditions, including in situ acquisitions. As a specific biological application, we present several examples of restorations of three-dimensional confocal images acquired inside an intact preparation of the hearing organ. We also provide a quantitative assessment of the gain in quality achieved by wavelet-aided restorations over classical deconvolution schemes, based on a set of numerical experiments that we performed with test images. PMID:11325744

  13. A Marked Poisson Process Driven Latent Shape Model for 3D Segmentation of Reflectance Confocal Microscopy Image Stacks of Human Skin.

    PubMed

    Ghanta, Sindhu; Jordan, Michael I; Kose, Kivanc; Brooks, Dana H; Rajadhyaksha, Milind; Dy, Jennifer G

    2016-10-05

    Segmenting objects of interest from 3D datasets is a common problem encountered in biological data. Small field of view and intrinsic biological variability combined with optically subtle changes of intensity, resolution and low contrast in images make the task of segmentation difficult, especially for microscopy of unstained living or freshly excised thick tissues. Incorporating shape information in addition to the appearance of the object of interest can often help improve segmentation performance. However, shapes of objects in tissue can be highly variable and design of a flexible shape model that encompasses these variations is challenging. To address such complex segmentation problems, we propose a unified probabilistic framework that can incorporate the uncertainty associated with complex shapes, variable appearance and unknown locations. The driving application which inspired the development of this framework is a biologically important segmentation problem: the task of automatically detecting and segmenting the dermal-epidermal junction (DEJ) in 3D reflectance confocal microscopy (RCM) images of human skin. RCM imaging allows noninvasive observation of cellular, nuclear and morphological detail. The DEJ is an important morphological feature as it is where disorder, disease and cancer usually start. Detecting the DEJ is challenging because it is a 2D surface in a 3D volume which has strong but highly variable number of irregularly spaced and variably shaped "peaks and valleys". In addition, RCM imaging resolution, contrast and intensity vary with depth. Thus a prior model needs to incorporate the intrinsic structure while allowing variability in essentially all its parameters. We propose a model which can incorporate objects of interest with complex shapes and variable appearance in an unsupervised setting by utilizing domain knowledge to build appropriate priors of the model. Our novel strategy to model this structure combines a spatial Poisson process with

  14. A Marked Poisson Process Driven Latent Shape Model for 3D Segmentation of Reflectance Confocal Microscopy Image Stacks of Human Skin.

    PubMed

    Ghanta, Sindhu; Jordan, Michael I; Kose, Kivanc; Brooks, Dana H; Rajadhyaksha, Milind; Dy, Jennifer G

    2017-01-01

    Segmenting objects of interest from 3D data sets is a common problem encountered in biological data. Small field of view and intrinsic biological variability combined with optically subtle changes of intensity, resolution, and low contrast in images make the task of segmentation difficult, especially for microscopy of unstained living or freshly excised thick tissues. Incorporating shape information in addition to the appearance of the object of interest can often help improve segmentation performance. However, the shapes of objects in tissue can be highly variable and design of a flexible shape model that encompasses these variations is challenging. To address such complex segmentation problems, we propose a unified probabilistic framework that can incorporate the uncertainty associated with complex shapes, variable appearance, and unknown locations. The driving application that inspired the development of this framework is a biologically important segmentation problem: the task of automatically detecting and segmenting the dermal-epidermal junction (DEJ) in 3D reflectance confocal microscopy (RCM) images of human skin. RCM imaging allows noninvasive observation of cellular, nuclear, and morphological detail. The DEJ is an important morphological feature as it is where disorder, disease, and cancer usually start. Detecting the DEJ is challenging, because it is a 2D surface in a 3D volume which has strong but highly variable number of irregularly spaced and variably shaped "peaks and valleys." In addition, RCM imaging resolution, contrast, and intensity vary with depth. Thus, a prior model needs to incorporate the intrinsic structure while allowing variability in essentially all its parameters. We propose a model which can incorporate objects of interest with complex shapes and variable appearance in an unsupervised setting by utilizing domain knowledge to build appropriate priors of the model. Our novel strategy to model this structure combines a spatial Poisson

  15. Applicability of confocal laser scanning microscopy for evaluation and monitoring of cutaneous wound healing

    NASA Astrophysics Data System (ADS)

    Lange-Asschenfeldt, Susanne; Bob, Adrienne; Terhorst, Dorothea; Ulrich, Martina; Fluhr, Joachim; Mendez, Gil; Roewert-Huber, Hans-Joachim; Stockfleth, Eggert; Lange-Asschenfeldt, Bernhard

    2012-07-01

    There is a high demand for noninvasive imaging techniques for wound assessment. In vivo reflectance confocal laser scanning microscopy (CLSM) represents an innovative optical technique for noninvasive evaluation of normal and diseased skin in vivo at near cellular resolution. This study was designed to test the feasibility of CLSM for noninvasive analysis of cutaneous wound healing in 15 patients (7 male/8 female), including acute and chronic, superficial and deep dermal skin wounds. A commercially available CLSM system was used for the assessment of wound bed and wound margins in order to obtain descriptive cellular and morphological parameters of cutaneous wound repair noninvasively and over time. CLSM was able to visualize features of cutaneous wound repair in epidermal and superficial dermal wounds, including aspects of inflammation, neovascularisation, and tissue remodelling in vivo. Limitations include the lack of mechanic fixation of the optical system on moist surfaces restricting the analysis of chronic skin wounds to the wound margins, as well as a limited optical resolution in areas of significant slough formation. By describing CLSM features of cutaneous inflammation, vascularisation, and epithelialisation, the findings of this study support the role of CLSM in modern wound research and management.

  16. Neurosurgical confocal endomicroscopy: A review of contrast agents, confocal systems, and future imaging modalities

    PubMed Central

    Zehri, Aqib H.; Ramey, Wyatt; Georges, Joseph F.; Mooney, Michael A.; Martirosyan, Nikolay L.; Preul, Mark C.; Nakaji, Peter

    2014-01-01

    Background: The clinical application of fluorescent contrast agents (fluorescein, indocyanine green, and aminolevulinic acid) with intraoperative microscopy has led to advances in intraoperative brain tumor imaging. Their properties, mechanism of action, history of use, and safety are analyzed in this report along with a review of current laser scanning confocal endomicroscopy systems. Additional imaging modalities with potential neurosurgical utility are also analyzed. Methods: A comprehensive literature search was performed utilizing PubMed and key words: In vivo confocal microscopy, confocal endomicroscopy, fluorescence imaging, in vivo diagnostics/neoplasm, in vivo molecular imaging, and optical imaging. Articles were reviewed that discussed clinically available fluorophores in neurosurgery, confocal endomicroscopy instrumentation, confocal microscopy systems, and intraoperative cancer diagnostics. Results: Current clinically available fluorescent contrast agents have specific properties that provide microscopic delineation of tumors when imaged with laser scanning confocal endomicroscopes. Other imaging modalities such as coherent anti-Stokes Raman scattering (CARS) microscopy, confocal reflectance microscopy, fluorescent lifetime imaging (FLIM), two-photon microscopy, and second harmonic generation may also have potential in neurosurgical applications. Conclusion: In addition to guiding tumor resection, intraoperative fluorescence and microscopy have the potential to facilitate tumor identification and complement frozen section analysis during surgery by providing real-time histological assessment. Further research, including clinical trials, is necessary to test the efficacy of fluorescent contrast agents and optical imaging instrumentation in order to establish their role in neurosurgery. PMID:24872922

  17. Research and application on imaging technology of line structure light based on confocal microscopy

    NASA Astrophysics Data System (ADS)

    Han, Wenfeng; Xiao, Zexin; Wang, Xiaofen

    2009-11-01

    In 2005, the theory of line structure light confocal microscopy was put forward firstly in China by Xingyu Gao and Zexin Xiao in the Institute of Opt-mechatronics of Guilin University of Electronic Technology. Though the lateral resolution of line confocal microscopy can only reach or approach the level of the traditional dot confocal microscopy. But compared with traditional dot confocal microscopy, it has two advantages: first, by substituting line scanning for dot scanning, plane imaging only performs one-dimensional scanning, with imaging velocity greatly improved and scanning mechanism simplified, second, transfer quantity of light is greatly improved by substituting detection hairline for detection pinhole, and low illumination CCD is used directly to collect images instead of photoelectric intensifier. In order to apply the line confocal microscopy to practical system, based on the further research on the theory of the line confocal microscopy, imaging technology of line structure light is put forward on condition of implementation of confocal microscopy. Its validity and reliability are also verified by experiments.

  18. 3D Imaging of Porous Media Using Laser Scanning Confocal Microscopy with Application to Microscale Transport Processes

    SciTech Connect

    Fredrich, J.T.

    1999-02-10

    We present advances in the application of laser scanning confocal microscopy (LSCM) to image, reconstruct, and characterize statistically the microgeometry of porous geologic and engineering materials. We discuss technical and practical aspects of this imaging technique, including both its advantages and limitations. Confocal imaging can be used to optically section a material, with sub-micron resolution possible in the lateral and axial planes. The resultant volumetric image data, consisting of fluorescence intensities for typically {approximately}50 million voxels in XYZ space, can be used to reconstruct the three-dimensional structure of the two-phase medium. We present several examples of this application, including studying pore geometry in sandstone, characterizing brittle failure processes in low-porosity rock deformed under triaxial loading conditions in the laboratory, and analyzing the microstructure of porous ceramic insulations. We then describe approaches to extract statistical microgeometric descriptions from volumetric image data, and present results derived from confocal volumetric data sets. Finally, we develop the use of confocal image data to automatically generate a three-dimensional mesh for numerical pore-scale flow simulations.

  19. Design, operation and applications of a visible-light confocal scanning Fourier transform Raman microscope for volumetric Raman spectrochemical imaging

    NASA Astrophysics Data System (ADS)

    Brenan, Colin John Herbert

    A new type of confocal Raman microscope called a Fourier transform confocal Raman microscope (FT-CRM) was designed, built and characterized with respect to its spatio-spectral imaging properties. Several different applications of the FT-CRM are presented that take advantage of its unique spectral and spatial imaging characteristics. The instrument combines focused illumination with spatially-filtered detection in a confocal optical configuration to collect photons scattered from a diffraction-limited volume in the sample (typically [<]5×10-18/ m3) and reject photons from outside that region. The molecular vibrational information encoded in the inelastic, or Raman, spectral component of light scattered from the confocal volume is measured with a visible light Fourier transform Raman spectrometer. By scanning the sample relative to the confocal volume, a volumetric Raman spectrochemical image of the sample can be constructed. Raman scattering is an inherently inefficient process; hence an optimal radius pinhole must be found that balances the FT-CRM optical throughput against the microscope spatial resolution and image contrast. Detailed experimental measurements mapped out the FT-CRM spatial response (axial and lateral), optical throughput and image signal-to-background and signal-to-noise ratios as a function of pinhole radius. Excellent agreement was found between these measurements and the predictions of a theoretical microscope model also developed as part of this thesis. Several applications of the FT-CRM included volumetric compositional imaging of three-dimensional chemically inhomogeneous materials such as cellulose and polyester fibers in water or two immiscible optically- similar liquids, water and trichloroehthylene, in a porous quartz sandstone matrix. The potential of the FT- CRM for non-invasive spectrochemical detection and imaging through a turbid tissue-like medium was demonstrated and a new spectral estimator, Fast Orthogonal Search, was evaluated

  20. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR QUANTIFYING CYTOMETRIC APPLICATIONS WITH SPECTROSCOPIC INSTRUMENTS

    EPA Science Inventory

    The confocal laser-scanning microscopy (CLSM) has enormous potential in many biological fields. The goal of a CLSM is to acquire and quantify fluorescence and in some instruments acquire spectral characterization of the emitted signal. The accuracy of these measurements demands t...

  1. Application and development of a spectrally-resolved confocal microscope: A study of lipofuscin emission properties

    NASA Astrophysics Data System (ADS)

    Haralampus-Grynaviski, Nicole Marie

    A unique spectrally-resolved confocal microscope is developed for use in biophysical applications. This microscope enables the rapid collection of the complete emission spectra for every pixel in a fluorescence image. The basic optical design and function of the device are assessed through examination of fluorescently labeled beads, using both one- and two-photon excitation. The spatial resolution of the device is found to approach the diffraction limit in the lateral plane and ˜2 mum in the axial plane. This device can readily distinguish between overlapping emissions which are not easily differentiated using standard filter techniques. The potential of this device to be used as a detection method in DNA sequence experiments is demonstrated. Images of a human skin tissue section and a mouse kidney section are presented which demonstrate the structure and spectra of biologic samples can be resolved. The emission properties of human ocular lipofuscin, LF, a heterogeneous auto-fluorescent material associated with age-related macular degeneration is investigated in detail. Isolated LF granules show substantial variation in emission spectra. Near-field scanning microscopy experiments find the emissive regions on a single LF granule are homogeneous on the ˜150 nm scale and confirm results obtained on the microscope developed here. For ˜100 studied LF deposits, the histogram of the measured peak emission is centered around 18,000 cm-1 (555 nm). The average emission spectra for large LF aggregates (peak 17,150 cm-1) is red-shifted compared to the average emission from small individual granules (peak 17,600 cm-1). The average LF granule emission observed here is similar to previously reported bulk LF emission and the emission of a previously identified LF chromophore, A2E. Individual LF granules show a broad range in emission maximum whether the LF is isolated from multiple donors or examined within the cells of a single donor. Multiple as yet unidentified chromophores

  2. Confocal Raman spectroscopic analysis of cross-linked ultra-high molecular weight polyethylene for application in artificial hip joints.

    PubMed

    Pezzotti, Giuseppe; Kumakura, Tsuyoshi; Yamada, Kiyotaka; Tateiwa, Toshiyuki; Puppulin, Leonardo; Zhu, Wenliang; Yamamoto, Kengo

    2007-01-01

    Confocal spectroscopic techniques are applied to selected Raman bands to study the microscopic features of acetabular cups made of ultra-high molecular weight polyethylene (UHMWPE) before and after implantation in vivo. The micrometric lateral resolution of a laser beam focused on the polymeric surface (or subsurface) enables a highly resolved visualization of 2-D conformational population patterns, including crystalline, amorphous, orthorhombic phase fractions, and oxidation index. An optimized confocal probe configuration, aided by a computational deconvolution of the optical probe, allows minimization of the probe size along the in-depth direction and a nondestructive evaluation of microstructural properties along the material subsurface. Computational deconvolution is also attempted, based on an experimental assessment of the probe response function of the polyethylene Raman spectrum, according to a defocusing technique. A statistical set of high-resolution microstructural data are collected on a fully 3-D level on gamma-ray irradiated UHMWPE acetabular cups both as-received from the maker and after retrieval from a human body. Microstructural properties reveal significant gradients along the immediate material subsurface and distinct differences are found due to the loading history in vivo, which cannot be revealed by conventional optical spectroscopy. The applicability of the confocal spectroscopic technique is valid beyond the particular retrieval cases examined in this study, and can be easily extended to evaluate in-vitro tested components or to quality control of new polyethylene brands. Confocal Raman spectroscopy may also contribute to rationalize the complex effects of gamma-ray irradiation on the surface of medical grade UHMWPE for total joint replacement and, ultimately, to predict their actual lifetime in vivo.

  3. Confocal scanning laser microscopy and quantitative image analysis: application to cream cheese microstructure investigation.

    PubMed

    Fenoul, F; Le Denmat, M; Hamdi, F; Cuvelier, G; Michon, C

    2008-04-01

    The naked eye observation of cream cheese confocal scanning laser microscopy images only provides qualitative information about its microstructure. Because those products are dense dairy gels, confocal scanning laser microscopy images of 2 different cream cheeses may appear close. Quantitative image analysis is then necessary to compensate for human eye deficiency (e.g., lack of precision, subjectivity). Two kinds of quantitative image analysis were performed in this study: high-order statistical methods and grayscale mathematical morphology. They were applied to study the microstructure of 3 different cream cheeses (same manufacturing process, same dry matter content, but different fat and protein contents). Advantages and drawbacks of both methods are reviewed. The way they may be used to describe cream cheese microstructure is also presented.

  4. Application of laser differential confocal technique in back vertex power measurement for phoropters

    NASA Astrophysics Data System (ADS)

    Li, Fei; Li, Lin; Ding, Xiang; Liu, Wenli

    2012-10-01

    A phoropter is one of the most popular ophthalmic instruments used in optometry and the back vertex power (BVP) is one of the most important parameters to evaluate the refraction characteristics of a phoropter. In this paper, a new laser differential confocal vertex-power measurement method which takes advantage of outstanding focusing ability of laser differential confocal (LDC) system is proposed for measuring the BVP of phoropters. A vertex power measurement system is built up. Experimental results are presented and some influence factor is analyzed. It is demonstrated that the method based on LDC technique has higher measurement precision and stronger environmental anti-interference capability compared to existing methods. Theoretical analysis and experimental results indicate that the measurement error of the method is about 0.02m-1.

  5. Application of regularized Richardson–Lucy algorithm for deconvolution of confocal microscopy images

    PubMed Central

    Laasmaa, M; Vendelin, M; Peterson, P

    2011-01-01

    Although confocal microscopes have considerably smaller contribution of out-of-focus light than widefield microscopes, the confocal images can still be enhanced mathematically if the optical and data acquisition effects are accounted for. For that, several deconvolution algorithms have been proposed. As a practical solution, maximum-likelihood algorithms with regularization have been used. However, the choice of regularization parameters is often unknown although it has considerable effect on the result of deconvolution process. The aims of this work were: to find good estimates of deconvolution parameters; and to develop an open source software package that would allow testing different deconvolution algorithms and that would be easy to use in practice. Here, Richardson–Lucy algorithm has been implemented together with the total variation regularization in an open source software package IOCBio Microscope. The influence of total variation regularization on deconvolution process is determined by one parameter. We derived a formula to estimate this regularization parameter automatically from the images as the algorithm progresses. To assess the effectiveness of this algorithm, synthetic images were composed on the basis of confocal images of rat cardiomyocytes. From the analysis of deconvolved results, we have determined under which conditions our estimation of total variation regularization parameter gives good results. The estimated total variation regularization parameter can be monitored during deconvolution process and used as a stopping criterion. An inverse relation between the optimal regularization parameter and the peak signal-to-noise ratio of an image is shown. Finally, we demonstrate the use of the developed software by deconvolving images of rat cardiomyocytes with stained mitochondria and sarcolemma obtained by confocal and widefield microscopes. PMID:21323670

  6. Scanning computed confocal imager

    DOEpatents

    George, John S.

    2000-03-14

    There is provided a confocal imager comprising a light source emitting a light, with a light modulator in optical communication with the light source for varying the spatial and temporal pattern of the light. A beam splitter receives the scanned light and direct the scanned light onto a target and pass light reflected from the target to a video capturing device for receiving the reflected light and transferring a digital image of the reflected light to a computer for creating a virtual aperture and outputting the digital image. In a transmissive mode of operation the invention omits the beam splitter means and captures light passed through the target.

  7. [Application of confocal micro-beam X-ray fluorescence in nondestructive scanning analysis of the distribution of elements in a single hair].

    PubMed

    Liu, He-He; Liu, Zhi-Guo; Sun, Tian-Xi; Peng, Song; Zhao, Wei-Gang; Sun, Wei-Yuan; Li, Yu-De; Lin, Xiao-Yan; Zhao, Guang-Cui; Luo, Ping; Ding, Xun-Liang

    2013-11-01

    The confocal micro X-ray fluorescence (XRF) based on polycapillary X-ray lens and conventional X-ray source was used to carry out the scanning analysis of the distribution of the elements in a single hair. The elemental distribution in the single hair was obtained. In the confocal micro XRF technology, the output focal spot of the polycapillary focusing X-ray lens and the input focal spot of the polycapillary parallel X-ray lens were adjusted confocally. The detector could only detect the X-rays from the overlapping foci. This confocal structure decreased the effects of the background on the X-ray spectra, and was accordingly helpful for improving the accuracy of this XRF technology. A polycapillary focusing X-ray lens with a high gain in power density was used to decrease the requirement of power of the X-ray source used in this confocal technology, and made it possible to perform such confocal micro XRF analysis by using the conventional X-ray source with low cost. Experimental results indicated that the confocal micro X-ray fluorescence based on polycapillary X-ray lens had potential applications in analyzing the elemental distribution of individual hairs.

  8. EUS-Guided Needle-Based Confocal Laser Endomicroscopy: A Novel Technique With Emerging Applications.

    PubMed

    Bhutani, Manoop S; Koduru, Pramoda; Joshi, Virendra; Karstensen, John G; Saftoiu, Adrian; Vilmann, Peter; Giovannini, Marc

    2015-04-01

    Endoscopic ultrasound (EUS) has emerged as an excellent tool for imaging the gastrointestinal tract, as well as surrounding structures. EUS-guided fine-needle aspiration (EUS-FNA) has become the standard of care for the tissue sampling of a variety of masses and lymph nodes within and around the gut, providing further diagnostic and staging information. Confocal laser endomicroscopy (CLE) is a novel endoscopic method that enables imaging at a subcellular level of resolution during endoscopy, allowing up to 1000-fold magnification of tissue and providing an optical biopsy. A new procedure that has been developed in the past few years is needle-based confocal laser endomicroscopy (nCLE), which involves a mini-CLE probe that can be passed through a 1 9-gauge needle during EUS-FNA. This enables the real-time visualization of tissue at a microscopic level, with the potential to further improve the diagnostic accuracy of EUS-FNA. The device has been studied in animals as well as in humans, and the results so far have been promising. Recently, this method has also been used for the visualization of regulatory proteins and receptors in the pancreas, setting a cornerstone for nCLE in molecular imaging. The aim of this article is to review the role of EUS-guided nCLE in modern endoscopy and its implications in molecular imaging.

  9. Infrared Reflective Filter and Its Applications

    NASA Astrophysics Data System (ADS)

    Honda, Kiyokazu; Ishizaki, Ariyoshi; Yuge, Youji; Saitoh, Tokuyoshi

    1983-12-01

    A thin film, which reflects infra-red ray while transmits visible light, is discussed in a background of energy saving incandescent lamps. The film which consists of multi-layer Ti02-Si02 film reflects infra-red ray effectively and has a high heat resistance. This film is formed from organometallic solutions by dipping method. In order to carry out multi-layer coatings, the organometallic solutions are improved. A film on a substrate turns into a metalic oxide film having desired optical thickness and refractive index. The optical properties of this film and its application to tubular tungsten halogen lamps are discussed in this paper.

  10. Total internal reflection ellipsometry: principles and applications.

    PubMed

    Arwin, Hans; Poksinski, Michal; Johansen, Knut

    2004-05-20

    A concept for a measurement technique based on ellipsometry in conditions of total internal reflection is presented. When combined with surface plasmon resonance (SPR) effects, this technique becomes powerful for monitoring and analyzing adsorption and desorption on thin semitransparent metal films as well as for analyzing the semitransparent films themselves. We call this technique total internal reflection ellipsometry (TIRE). The theory of ellipsometry under total internal reflection combined with SPR is discussed for some simple cases. For more advanced cases and to prove the concept, simulations are performed with the Fresnel formalism. The use of TIRE is exemplified by applications in protein adsorption, corrosion monitoring, and adsorption from opaque liquids on metal surfaces. Simulations and experiments show greatly enhanced thin-film sensitivity compared with ordinary ellipsometry.

  11. Towards real-time image deconvolution: application to confocal and STED microscopy

    PubMed Central

    Zanella, R.; Zanghirati, G.; Cavicchioli, R.; Zanni, L.; Boccacci, P.; Bertero, M.; Vicidomini, G.

    2013-01-01

    Although deconvolution can improve the quality of any type of microscope, the high computational time required has so far limited its massive spreading. Here we demonstrate the ability of the scaled-gradient-projection (SGP) method to provide accelerated versions of the most used algorithms in microscopy. To achieve further increases in efficiency, we also consider implementations on graphic processing units (GPUs). We test the proposed algorithms both on synthetic and real data of confocal and STED microscopy. Combining the SGP method with the GPU implementation we achieve a speed-up factor from about a factor 25 to 690 (with respect the conventional algorithm). The excellent results obtained on STED microscopy images demonstrate the synergy between super-resolution techniques and image-deconvolution. Further, the real-time processing allows conserving one of the most important property of STED microscopy, i.e the ability to provide fast sub-diffraction resolution recordings. PMID:23982127

  12. Improving Diagnostic Accuracy of Dermoscopically Equivocal Pink Cutaneous Lesions with Reflectance Confocal Microscopy in Telemedicine Settings: Double Reader Concordance Evaluation of 316 Cases

    PubMed Central

    Roterman-Konieczna, I.; Bassoli, S.

    2016-01-01

    Background Solitary pink lesions in differential diagnosis with hypopigmented/amelanotic melanoma present a diagnostic challenge in daily practice and are regularly referred for second expert opinion. Reflectance confocal microscopy (RCM) has been shown to improve diagnostic accuracy of dermoscopically equivocal pink lesions. No studies have been performed to evaluate the effect of adding a second expert reader and automatic removal of lesions with discordant management recommendations and its potential effect on diagnostic sensitivity and final management of these lesions in retrospective or telemedicine settings. Objective To improve diagnostic accuracy and reduce potential mismanagement of dermoscopically equivocal pink cutaneous lesions by implementing double reader concordance evaluation of RCM images. Methods 316 dermoscopically equivocal pink lesions with dermoscopy-RCM image sets were evaluated retrospectively. Accuracy of three readers was evaluated by single reader evaluation of dermoscopy only and dermoscopy-RCM image sets and finally by double reader evaluation of dermoscopy-RCM image sets. Lesions with discordant diagnosis between two readers were automatically recommended for excision. Results Dermoscopy only evaluation resulted in an overall sensitivity of 95.9% and specificity of 33.6%, with 1 of 12 amelanotic melanomas mismanaged. Dermoscopy-RCM image set single reader evaluation resulted in an overall sensitivity of 93.9% and overall specificity of 54.2%, with 1 of 12 melanomas mismanaged. Dermoscopy-RCM image set double reader concordance evaluation resulted in an overall sensitivity of 98.3% and specificity of 42.7%, with no amelanotic melanoma mismanagement. Conclusion Evaluation of dermoscopy-RCM image sets of equivocal pink lesions by a single reader in telemedicine settings is limited by the potential for misdiagnosis of dangerous malignant lesions. Double reader concordance evaluation with automatic referral of lesions for removal in the

  13. Rheology and confocal reflectance microscopy as probes of mechanical properties and structure during collagen and collagen/hyaluronan self-assembly.

    PubMed

    Yang, Ya-li; Kaufman, Laura J

    2009-02-18

    In this work, the gelation of three-dimensional collagen and collagen/hyaluronan (HA) composites is studied by time sweep rheology and time lapse confocal reflectance microscopy (CRM). To investigate the complementary nature of these techniques, first collagen gel formation is investigated at concentrations of 0.5, 1.0, and 1.5 mg/mL at 37 degrees C and 32 degrees C. The following parameters are used to describe the self-assembly process in all gels: the crossover time (t(c)), the slope of the growth phase (k(g)), and the arrest time (t(a)). The first two measures are determined by rheology, and the third by CRM. A frequency-independent rheological measure of gelation, t(g), is also measured at 37 degrees C. However, this quantity cannot be straightforwardly determined for gels formed at 32 degrees C, indicating that percolation theory does not fully capture the dynamics of collagen network formation. The effects of collagen concentration and gelation temperature on k(g), t(c), and t(a) as well as on the mechanical properties and structure of these gels both during gelation and at equilibrium are elucidated. Composite collagen/HA gels are also prepared, and their properties are monitored at equilibrium and during gelation at 37 degrees C and 32 degrees C. We show that addition of HA subtly alters mechanical properties and structure of these systems both during the gelation process and at equilibrium. This occurs in a temperature-dependent manner, with the ratio of HA deposited on collagen fibers versus that distributed homogeneously between fibers increasing with decreasing gelation temperature. In addition to providing information on collagen and collagen/HA structure and mechanical properties during gelation, this work shows new ways in which rheology and microscopy can be used complementarily to reveal details of gelation processes.

  14. Dermoscopy-guided reflectance confocal microscopy of skin using high-NA objective lens with integrated wide-field color camera

    NASA Astrophysics Data System (ADS)

    Dickensheets, David L.; Kreitinger, Seth; Peterson, Gary; Heger, Michael; Rajadhyaksha, Milind

    2016-02-01

    Reflectance Confocal Microscopy, or RCM, is being increasingly used to guide diagnosis of skin lesions. The combination of widefield dermoscopy (WFD) with RCM is highly sensitive (~90%) and specific (~ 90%) for noninvasively detecting melanocytic and non-melanocytic skin lesions. The combined WFD and RCM approach is being implemented on patients to triage lesions into benign (with no biopsy) versus suspicious (followed by biopsy and pathology). Currently, however, WFD and RCM imaging are performed with separate instruments, while using an adhesive ring attached to the skin to sequentially image the same region and co-register the images. The latest small handheld RCM instruments offer no provision yet for a co-registered wide-field image. This paper describes an innovative solution that integrates an ultra-miniature dermoscopy camera into the RCM objective lens, providing simultaneous wide-field color images of the skin surface and RCM images of the subsurface cellular structure. The objective lens (0.9 NA) includes a hyperhemisphere lens and an ultra-miniature CMOS color camera, commanding a 4 mm wide dermoscopy view of the skin surface. The camera obscures the central portion of the aperture of the objective lens, but the resulting annular aperture provides excellent RCM optical sectioning and resolution. Preliminary testing on healthy volunteers showed the feasibility of combined WFD and RCM imaging to concurrently show the skin surface in wide-field and the underlying microscopic cellular-level detail. The paper describes this unique integrated dermoscopic WFD/RCM lens, and shows representative images. The potential for dermoscopy-guided RCM for skin cancer diagnosis is discussed.

  15. Skin healing and collagen changes of rats after fractional erbium:yttrium aluminum garnet laser: observation by reflectance confocal microscopy with confirmed histological evidence.

    PubMed

    Yang, Jing; Wang, Sha; Dong, Liyun; An, Xiangjie; Li, Yan; Li, Jun; Tu, Yating; Tao, Juan

    2016-08-01

    The fractional erbium:yttrium aluminum garnet (Er:YAG) laser is widely applied. Microstructural changes after laser treatment have been observed with histopathology. Epidermal and dermal microstructures have also been analyzed using reflectance confocal microscopy (RCM). However, no studies have compared these two types of microstructural changes in the same subject at multiple time points after irradiation, and it is unclear if these two types of changes are consistent. We use RCM to observe the effect of different laser energies on skin healing and collagen changes in the skin of Sprague-Dawley rats that had been irradiated by fractional Er:YAG lasering at different energies. RCM was used to observe skin healing and detect collagen changes at different time points. Collagen changes were observed using hematoxylin and eosin (H&E) staining and quantitatively analyzed by western blot. RCM showed that, irrespective of laser energy, microscopic treatment zones (MTZs) were larger at 1 day after irradiation. The MTZs then reduced in size from 3 to 7 days after irradiation. The higher the energy, the larger the MTZ area. The amount of collagen also increased with time from 1 day to 8 weeks. However, the increase in the collagen amount on both RCM and H&E staining was not influenced by the laser energy. Western blotting confirmed that the amount of type I and type III collagens increased over time, but there were no significant differences between the different energy groups (p > 0.05). In conclusion, RCM is a reliable technique for observing and evaluating skin healing and collagen expression after laser irradiation.

  16. A fully automated tortuosity quantification system with application to corneal nerve fibres in confocal microscopy images.

    PubMed

    Annunziata, Roberto; Kheirkhah, Ahmad; Aggarwal, Shruti; Hamrah, Pedram; Trucco, Emanuele

    2016-08-01

    Recent clinical research has highlighted important links between a number of diseases and the tortuosity of curvilinear anatomical structures like corneal nerve fibres, suggesting that tortuosity changes might detect early stages of specific conditions. Currently, clinical studies are mainly based on subjective, visual assessment, with limited repeatability and inter-observer agreement. To address these problems, we propose a fully automated framework for image-level tortuosity estimation, consisting of a hybrid segmentation method and a highly adaptable, definition-free tortuosity estimation algorithm. The former combines an appearance model, based on a Scale and Curvature-Invariant Ridge Detector (SCIRD), with a context model, including multi-range learned context filters. The latter is based on a novel tortuosity estimation paradigm in which discriminative, multi-scale features can be automatically learned for specific anatomical objects and diseases. Experimental results on 140 in vivo confocal microscopy images of corneal nerve fibres from healthy and unhealthy subjects demonstrate the excellent performance of our method compared to state-of-the-art approaches and ground truth annotations from 3 expert observers.

  17. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    SciTech Connect

    Shur, V. Ya. Zelenovskiy, P. S.

    2014-08-14

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  18. Novel application of confocal laser scanning microscopy and 3D volume rendering toward improving the resolution of the fossil record of charcoal.

    PubMed

    Belcher, Claire M; Punyasena, Surangi W; Sivaguru, Mayandi

    2013-01-01

    Variations in the abundance of fossil charcoals between rocks and sediments are assumed to reflect changes in fire activity in Earth's past. These variations in fire activity are often considered to be in response to environmental, ecological or climatic changes. The role that fire plays in feedbacks to such changes is becoming increasingly important to understand and highlights the need to create robust estimates of variations in fossil charcoal abundance. The majority of charcoal based fire reconstructions quantify the abundance of charcoal particles and do not consider the changes in the morphology of the individual particles that may have occurred due to fragmentation as part of their transport history. We have developed a novel application of confocal laser scanning microscopy coupled to image processing that enables the 3-dimensional reconstruction of individual charcoal particles. This method is able to measure the volume of both microfossil and mesofossil charcoal particles and allows the abundance of charcoal in a sample to be expressed as total volume of charcoal. The method further measures particle surface area and shape allowing both relationships between different size and shape metrics to be analysed and full consideration of variations in particle size and size sorting between different samples to be studied. We believe application of this new imaging approach could allow significant improvement in our ability to estimate variations in past fire activity using fossil charcoals.

  19. Clinical applicability of in vivo fluorescence confocal microscopy for noninvasive diagnosis and therapeutic monitoring of nonmelanoma skin cancer.

    PubMed

    Astner, Susanne; Dietterle, Susanne; Otberg, Nina; Röwert-Huber, Hans-Joachim; Stockfleth, Eggert; Lademann, Jürgen

    2008-01-01

    Excisional biopsies and routine histology remains the gold standard for the histomorphologic evaluation of normal and diseased skin. However, there is increasing interest in the development of noninvasive optical technologies for evaluation, diagnosis, and monitoring of skin disease in vivo. Fluorescent confocal microscopy is an innovative optical technology that has previously been used for morphologic evaluation of live human tissue. We evaluate the clinical applicability of a fluorescent confocal laser scanning microscope (FLSM) for a systematic evaluation of normal and diseased skin in vivo and in correlation with routine histology. A total of 40 patients were recruited to participate in the study. Skin sites of 10 participants with no prior history of skin disease served as controls and to evaluate topographic variations of normal skin in vivo. Thirty patients with a suspected diagnosis of nonmelanoma skin cancer were evaluated, whereby FLSM features of actinic keratoses (AK) and basal cell carcinoma (BCC) were recorded in an observational analysis. Selected BCCs were monitored for their skin response to topical therapy using Imiquimod as an immune-response modifier. A commercially available fluorescence microscope (OptiScan Ltd., Melbourne, Australia) was used to carry out all FLSM evaluations. Common FLSM features to AK and BCC included nuclear pleomorphism at the level of the granular and spinous layer and increased vascularity in the superficial dermal compartment. Even though the presence of superficial disruption and mere atypia of epidermal keratinocytes was more indicative of AK, the nesting of atypical basal cells, increased blood vessel tortuosity, and nuclear polarization were more typical for BCC. All diagnoses were confirmed by histology. FLSM allowed a monitoring of the local immune response following therapy with Imiquimod and demonstrated a continuous normalization of diseased skin on repeated evaluations over time. This study illustrates

  20. Application of confocal laser scanning microscopy for the diagnosis of amyloidosis.

    PubMed

    Castellani, Chiara; Fedrigo, Marny; Frigo, Anna Chiara; Barbera, Mila Della; Thiene, Gaetano; Valente, Marialuisa; Adami, Fausto; Angelini, Annalisa

    2017-02-20

    We analysed specificity and sensitivity of confocal laser microscopy (CLSM) on tissue sections for a diagnosis of amyloidosis, in an attempt to reduce technical errors and better standardise pathological diagnosis. We first set up a protocol for the use of CLSM on this type of specimen, using a group of 20 amyloid negative and 20 positive samples. Of all specimens, 2, 4 and 8-μm sections were cut. Sections were stained with Congo red (CR) and thioflavin-T (ThT) and observed by cross-polarised light microscopy (CR-PL), epifluorescence microscopy (CRF-epiFM and ThT-epiFM) and CLSM (CRF-CLSM and ThT-CLSM). To validate the method in a diagnostic setting, we examined tissue samples from 116 consecutive patients with clinical suspicion of amyloidosis, selected from the period 2005 to 2014 from the database of the Pathology Unit of the University of Padua. The results were compared with those of transmission electron microscopy (TEM), which we consider as reference. We found that with CRF-CLSM, the false negative rate was reduced from 17 to 5%, while the sensitivity of detection increased to 12%. The results were in complete agreement with those of TEM ThT-CLSM; both sensitivity and specificity were 100%. Finally, ThT-CLSM results did not vary with section thickness, and small amounts of amyloid could even be detected in 2-μm sections. In conclusion, we found ThT-CLSM to be more sensitive as a screening method for amyloidosis than CR and ThT epifluorescence optical imaging. The method was easier to standardise, provided images with better resolution and resulted in more consistent pathologist diagnoses.

  1. Enhanced quantitative confocal microscopy and its application for the measurement of tympanic membrane thickness

    NASA Astrophysics Data System (ADS)

    Kuypers, Liesbeth

    2005-11-01

    This work shows that confocal microscopy allows a quantitative study of delicate 3D-biotissue in fresh condition, thus avoiding histological preparation processes. The developed procedure results in exact and accurate thickness data for mum-sized objects with a measuring error of less than 1mum. It is, however, necessary to take into account the effect of focal shift in the case of refractive index mismatch to obtain such precise data. The use of the proposed method is advised instead of the use of a paraxial approximation for the axial scale correction because the method improves measurement precision by a factor of four. The axial scaling correction factors obtained in this work show that for most practical situations the correction cannot be ignored when one wants to obtain precise quantitative data. The thickness correction method can also be used to determine with high accuracy the index of refraction of biological tissue. The thickness measurement method was applied to fresh, untreated tympanic membranes of the gerbil, the cat and the human. Thickness had to be measured at many points as it differs strongly across the membrane. Similar thickness distributions were found in all pars tensas measured even across the species studied: (1) a very thin, central region with a rather constant thickness, curving as a horse shoe upwards around the manubrium (thickness: gerbil: about 7mum, cat: about 10mum, human: large inter-specimen variation: 40mum-120mum), (2) a thinnest zone at the inferior side, (3) a thicker zone at the supero-anterior side, (4) superior to the umbo, an anterior region thicker than the posterior region, (5) maximal thicknesses in a very small region near the entire manubrium and the entire annular periphery. The pars flaccida is found to be thicker than the pars tensa. It shows no central homogeneous zone: the thickness varies irregularly and very rapidly over short distances. Arbitrarily spaced bumps and notches are present over the entire pars

  2. Reflection imaging of China ink-perfused brain vasculature using confocal laser-scanning microscopy after clarification of brain tissue by the Spalteholz method.

    PubMed

    Gutierre, R C; Vannucci Campos, D; Mortara, R A; Coppi, A A; Arida, R M

    2017-01-05

    Confocal laser-scanning microscopy is a useful tool for visualizing neurons and glia in transparent preparations of brain tissue from laboratory animals. Currently, imaging capillaries and venules in transparent brain tissues requires the use of fluorescent proteins. Here, we show that vessels can be imaged by confocal laser-scanning microscopy in transparent cortical, hippocampal and cerebellar preparations after clarification of China ink-injected specimens by the Spalteholz method. This method may be suitable for global, three-dimensional, quantitative analyses of vessels, including stereological estimations of total volume and length and of surface area of vessels, which constitute indirect approaches to investigate angiogenesis.

  3. Label-free and non-invasive discrimination of HaCaT and melanoma cells in a co-culture model by hyperspectral confocal reflectance microscopy.

    PubMed

    Bertani, Francesca R; Botti, Elisabetta; Ferrari, Luisa; Mussi, Valentina; Costanzo, Antonio; D'Alessandro, Marco; Cilloco, Francesco; Selci, Stefano

    2016-06-01

    A novel hyperspectral confocal microscopy method to separate different cell populations in a co-culture model is presented here. The described methodological and instrumental approach allows discrimination of different cell types using a non-invasive, label free method with good accuracy with a single cell resolution. In particular, melanoma cells are discriminated from HaCaT cells by hyperspectral confocal imaging, principal component analysis and optical frequencies signing, as confirmed by fluorescence labelling cross check. The identification seems to be quite robust to be insensitive to the cellular shape within the studied samples, enabling to separate cells according to their cytotype down to a single cell sensitivity. Set of hyperspectral images of melanoma-keratinocytes co-culture model (left), score plot of principal component analysis and spectral analysis of principal components coefficients (center), label-free spectral identification of cell populations (right).

  4. Confocal Microscopy Of The Eye.

    NASA Astrophysics Data System (ADS)

    Masters, Barry R.

    1989-12-01

    A laser scanning confocal microscope was used to study the structure of human donor eyes and enucleated rabbit eyes. Reflected light confocal images were obtained with a Leitz water immersion objective (50X, NA 1.0). A drop of bicarbonate Ringer's was placed between the objective and the tissue to optically couple the tissue. The confocal microscope was used to image the following objects within the eye: superficial epithelial cells, super basal and basal epithelial cells, basement membrane, stromal nerve plexus, nerve fibers, nuclei and cell bodies of stromal keratocytes, cell processes of stromal keratocytes, Descemet's membrane, and the endothelial cells. In addition, the ocular lens and excised retina were imaged. The confocal microscope produces images of the eye with the following enhanced features: increased lateral resolution, decreased depth of field, and increased contrast of transparent ocular structures. It is concluded that confocal imaging systems are an improvement over traditional optical instruments, and they may develop into a new tool for basic visual science and clinical ophthalmology.

  5. Reflection: Its Concepts and Applications in Geometry

    ERIC Educational Resources Information Center

    Man, Yiu Kwong

    2004-01-01

    This paper discusses the basic concepts of reflection and its related concepts in optics. It aims at providing examples on how to apply the principle of reflection in geometry. Explorations of the concepts involved via dynamic geometry software are also included.

  6. Nonscanning confocal ranging system

    NASA Astrophysics Data System (ADS)

    Sun, P. C.; Arons, E.

    1995-03-01

    We demonstrate a nonscanning confocal ranging system based on spatially incoherent interferometry. Such a system has significant advantages over the conventional confocal imaging system and other interferometric systems. We develop the theory in terms of coherence cells and demonstrate the equivalence of our method to the conventional confocal methods. Experimental results are also provided.

  7. Video-rate Scanning Confocal Microscopy and Microendoscopy

    PubMed Central

    Nichols, Alexander J.; Evans, Conor L.

    2011-01-01

    Confocal microscopy has become an invaluable tool in biology and the biomedical sciences, enabling rapid, high-sensitivity, and high-resolution optical sectioning of complex systems. Confocal microscopy is routinely used, for example, to study specific cellular targets1, monitor dynamics in living cells2-4, and visualize the three dimensional evolution of entire organisms5,6. Extensions of confocal imaging systems, such as confocal microendoscopes, allow for high-resolution imaging in vivo7 and are currently being applied to disease imaging and diagnosis in clinical settings8,9. Confocal microscopy provides three-dimensional resolution by creating so-called "optical sections" using straightforward geometrical optics. In a standard wide-field microscope, fluorescence generated from a sample is collected by an objective lens and relayed directly to a detector. While acceptable for imaging thin samples, thick samples become blurred by fluorescence generated above and below the objective focal plane. In contrast, confocal microscopy enables virtual, optical sectioning of samples, rejecting out-of-focus light to build high resolution three-dimensional representations of samples. Confocal microscopes achieve this feat by using a confocal aperture in the detection beam path. The fluorescence collected from a sample by the objective is relayed back through the scanning mirrors and through the primary dichroic mirror, a mirror carefully selected to reflect shorter wavelengths such as the laser excitation beam while passing the longer, Stokes-shifted fluorescence emission. This long-wavelength fluorescence signal is then passed to a pair of lenses on either side of a pinhole that is positioned at a plane exactly conjugate with the focal plane of the objective lens. Photons collected from the focal volume of the object are collimated by the objective lens and are focused by the confocal lenses through the pinhole. Fluorescence generated above or below the focal plane will

  8. Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach

    PubMed Central

    Nonaka, Kouichi; Ohata, Ken; Ban, Shinichi; Ichihara, Shin; Takasugi, Rumi; Minato, Yohei; Tashima, Tomoaki; Matsuyama, Yasushi; Takita, Maiko; Matsuhashi, Nobuyuki; Neumann, Helmut

    2015-01-01

    Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared

  9. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: APPLICATIONS FOR IMAGING MORPHOLOGY AND DEATH IN EMBRYOS AND REPRODUCTIVE TISSUE/ORGANS

    EPA Science Inventory

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. It is remarkable that procedures to test the performance of these machines are not done routinely by most investigators and thus many of the machines in the field are working at level...

  10. DURIP: A Confocal Imaging System for Ultra-Fast Three-Dimensional Transport Studies in Thermal Management Applications

    DTIC Science & Technology

    2011-12-01

    microelectronic devices. We studied evaporation of the water droplets on a micro-patterned Pyrex structure using the confocal microscope system. The micro...Phase-change.” American Physical Society, Spring, March 2011. 3. E.N. Wang, “Nanoengineered Surfaces for Microfluidics and Energy Systems.” Ontario-on-a-Chip, Toronto, CA, June 2011 (Invited keynote).

  11. Clinical applications of a real-time scanning-slit confocal microscope designed for real-time observations of the in-vivo human cornea

    NASA Astrophysics Data System (ADS)

    Masters, Barry R.

    1995-05-01

    We describe a new, real-time, flying slit confocal microscope, that has unique features and imaging characteristics for in vivo human ocular imaging. In vivo real-time confocal microscopy is currently used to investigate the tear film, renewal of the ocular surface, the role of epithelial innervation in epithelial cell proliferation, wound healing, kinetics of drug penetration, the effects of laser refractive surgery on the keratocyte activation and distribution in the stroma, and the nature of endothelial defects. The following clinical examples will be presented and discussed: confocal microscopy of normal human basal and wing cells in the epithelium, confocal microscopy of lamellar and penetrating corneal grafts, confocal microscopy of corneal ulcer, confocal microscopy of scar formation after herpes keratitis, and confocal microscopy of corneal innervation. The use of scanning slit confocal microscopes has unique advantages over other instrumental systems based on pinhole-containing Nipkow disks (tandem-scanning confocal microscopes) for clinical in vivo confocal microscopy.

  12. Application of confocal Raman microscopy to investigate casein micro-particles in blend casein/pectin films.

    PubMed

    Zhuang, Yu; Sterr, Julia; Kulozik, Ulrich; Gebhardt, Ronald

    2015-03-01

    Pectin triggers formation of casein micro-particles during solution casting. Confocal Raman microscopy revealed their composition and spatial dimension in resulting films. Peaks in the Raman spectra corresponded to those found in films prepared by either casein or pectin. This suggested that no conformational changes occurred after mixing. Raman images revealed incompatibility of both polymers because particles consisted of casein only and the surrounding matrix of pectin. Deformation of micro-particles into an oblate shape took place during film formation. In dried films, an empty space between casein and pectin was found in lateral dimension. In contrast, casein micro-particles overlapped with the pectin matrix in the vertical dimension.

  13. The application of in vivo laser confocal microscopy to the diagnosis and evaluation of meibomian gland dysfunction

    PubMed Central

    Matsumoto, Yukihiro; Sato, Enrique Adan; Ibrahim, Osama M.A.; Tsubota, Kazuo

    2008-01-01

    Purpose To evaluate the morphological changes of the meibomian glands (MG) in patients with meibomian gland dysfunction (MGD) compared to normal subjects by in vivo confocal microscopy and to investigate the relation of these changes to the clinical ocular surface findings and tear functions. Methods Twenty MGD patients and 15 normal subjects were recruited into this prospective study. Patients and controls underwent slit lamp examinations, tear film break-up time (BUT) measurements, fluorescein and Rose-Bengal stainings, Schirmer test I without anesthesia, tear evaporation rate assessment (TEROS), tear film lipid layer interferometry (DR-1), transillumination of the lids (meibography), MG expressibility test, and in vivo laser confocal microscopy of the lids (HRTII-RCM). Results The BUT, DR-1 tear film lipid layer interferometry grades, fluorescein and Rose-Bengal staining scores, MG drop out grade in meibography, and MG expressibility grades were significantly worse in MGD patients compared to normal controls (p<0.05). The severity of both MG dropout and MG expressibility related significantly with the BUT, DR-1 grades, and TEROS (p<0.05). The mean density of acinar units of MGs as measured by HRTII-RCM was significantly lower in MGD patients (47.6±26.6/mm2) than in control subjects (101.3±33.8/mm2; p<0.05). The mean acinar unit diameter as determined by HRTII-RCM was significantly larger in MGD patients (98.2±53.3 μm) than in controls (41.6±11.9 μm; p<0.05). Both the density and diameter of MG acinar units related significantly with the severity of MG dropout and MG expression grades (p<0.05). Conclusions In vivo confocal microscopy can effectively demonstrate the morphological changes of the MG in patients with MGD. Glandular acinar density and acinar unit diameter seemed to be promising new parameters of in vivo confocal microscopy, which is significantly related to the clinical ocular surface and tear function findings of MGD. PMID:18618006

  14. Transparent superhydrophobic surfaces for applications of controlled reflectance.

    PubMed

    Gou, Steven; Mossman, Michele; Whitehead, Lorne

    2012-04-10

    This work involves a new optical application for transparent superhydrophobic materials, which enables low-energy optical contact between a liquid and solid surface. The new technique described here uses this surface property to control the reflectance of a surface using frustration of total internal reflection. Surface chemistry and appropriate micro-scale and nano-scale geometries are combined to produce interfaces with low adhesion to water and the degree to which incident light is reflected at this interface is controlled by the movement of water, thereby modifying the optical characteristics at the interface. The low adhesion of water to superhydrophobic surfaces is particularly advantageous in imaging applications where power use must be minimized. This paper describes the general approach, as well as a proof-of-principle experiment in which the reflectance was controlled by moving a water drop into and out of contact with a superhydrophobic surface by variation of applied electrostatic pressure.

  15. CRAFT: Multimodality confocal skin imaging for early cancer diagnosis.

    PubMed

    Peng, Tong; Xie, Hao; Ding, Yichen; Wang, Weichao; Li, Zhiming; Jin, Dayong; Tang, Yuanhe; Ren, Qiushi; Xi, Peng

    2012-05-01

    Although histological analysis serves as a gold standard to cancer diagnosis, its application on skin cancer detection is largely prohibited due to its invasive nature. To obtain both the structural and pathological information in situ, a Confocal Reflectance/Auto-Fluorescence Tomography (CRAFT) system was established to examine the skin sites in vivo with both reflectance and autofluorescence modes simultaneously. Nude mice skin with cancerous sites and normal skin sites were imaged and compared with the system. The cellular density and reflective intensity in cancerous sites reflects the structural change of the tissue. With the decay coefficient analysis, the corresponding NAD(P)H decay index for cancerous sites is 1.65-fold that of normal sites, leading to a 97.8% of sensitivity and specificity for early cancer diagnosis. The results are verified by the followed histological analysis. Therefore, CRAFT may provide a novel method for the in vivo, non-invasive diagnosis of early cancer.

  16. Confocal microscopy in microgravity research.

    PubMed

    Goede, A P; Brakenhoff, G J; Woldringh, C L; Aalders, J W; Imhof, J P; van Kralingen, P; Mels, W A; Schreinemakers, P; Zegers, A

    1992-01-01

    We have studied the application and the feasibility of confocal scanning laser microscopy (CSLM) in microgravity research. Its superior spatial resolution and 3D imaging capabilities and its use of light as a probe, render this instrument ideally suited for the study of living biological material on a (sub-)cellular level. In this paper a number of pertinent biological microgravity experiments is listed, concentrating on the direct observation of developing cells and cellular structures under microgravity condition. A conceptual instrument design is also presented, aimed at sounding rocket application followed by Biorack/Biolab application at a later stage.

  17. Expanding imaging capabilities for microfluidics: applicability of darkfield internal reflection illumination (DIRI) to observations in microfluidics.

    PubMed

    Kawano, Yoshihiro; Otsuka, Chino; Sanzo, James; Higgins, Christopher; Nirei, Tatsuo; Schilling, Tobias; Ishikawa, Takuji

    2015-01-01

    Microfluidics is used increasingly for engineering and biomedical applications due to recent advances in microfabrication technologies. Visualization of bubbles, tracer particles, and cells in a microfluidic device is important for designing a device and analyzing results. However, with conventional methods, it is difficult to observe the channel geometry and such particles simultaneously. To overcome this limitation, we developed a Darkfield Internal Reflection Illumination (DIRI) system that improved the drawbacks of a conventional darkfield illuminator. This study was performed to investigate its utility in the field of microfluidics. The results showed that the developed system could clearly visualize both microbubbles and the channel wall by utilizing brightfield and DIRI illumination simultaneously. The methodology is useful not only for static phenomena, such as clogging, but also for dynamic phenomena, such as the detection of bubbles flowing in a channel. The system was also applied to simultaneous fluorescence and DIRI imaging. Fluorescent tracer beads and channel walls were observed clearly, which may be an advantage for future microparticle image velocimetry (μPIV) analysis, especially near a wall. Two types of cell stained with different colors, and the channel wall, can be recognized using the combined confocal and DIRI system. Whole-slide imaging was also conducted successfully using this system. The tiling function significantly expands the observing area of microfluidics. The developed system will be useful for a wide variety of engineering and biomedical applications for the growing field of microfluidics.

  18. Application of a reflectance model to the sensor planning system

    NASA Astrophysics Data System (ADS)

    Koutecký, Tomáś; Paloušek, David; Brandejs, Jan

    2015-05-01

    This study describes a new sensor planning system for the automatic generation of scanning positions based on a computer model of the part for digitization of sheet metal parts. The focus of this paper is in the application of a reflectance model into this sensor planning system. The goal of this sensor planning system and application of this model is to ensure fast, complete and accurate digitization of the parts for their inspection during serial-line production, especially in the automotive industry. A methodology of the sensor planning system consists of positions planning, their simulation for true visibility of the part elements using a reflectance model, and a simulation of the positions for robot reachability. Compared to previous studies, visual properties of the scanned parts' surface can be simulated precisely. The Nayar model is used as a reflectance model. This model is suitable for materials that are characterized by the combination of diffuse and specular reflections and uses three components of reflection: diffuse, specular lobe and specular spike. Results of the scanning that were obtained using an ATOS III Triple Scan fringe projection 3D scanner and a KUKA KR 60 HA industrial robot were compared to the simulation. The comparison based on the correspondence of the polygons area acquired in each sensor position (in simulation and in scanning) shows that in the performed measurements the median of differences between simulation and scanning is around 16%.

  19. Reflectance of metallic indium for solar energy applications

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.; Hasegawa, T.

    1984-01-01

    An investigation has been conducted in order to compile quantitative data on the reflective properties of metallic indium. The fabricated samples were of sufficiently high quality that differences from similar second-surface silvered mirrors were not apparent to the human eye. Three second-surface mirror samples were prepared by means of vacuum deposition techniques, yielding indium thicknesses of approximately 1000 A. Both hemispherical and specular measurements were made. It is concluded that metallic indium possesses a sufficiently high specular reflectance to be potentially useful in many solar energy applications.

  20. Reflectance Diffuse Optical Tomography: Its Application to Human Brain Mapping

    NASA Astrophysics Data System (ADS)

    Ueda, Yukio; Yamanaka, Takeshi; Yamashita, Daisuke; Suzuki, Toshihiko; Ohmae, Etsuko; Oda, Motoki; Yamashita, Yutaka

    2005-09-01

    We report the successful application of reflectance diffuse optical tomography (DOT) using near-infrared light with the new reconstruction algorithm that we developed to the observation of regional hemodynamic changes in the brain under specific mental tasks. Our results reveal the heterogeneous distribution of oxyhemoglobin and deoxyhemoglobin in the brain, showing complementary images of oxyhemoglobin and deoxyhemoglobin changes in certain regions. We conclude that our reflectance DOT has practical potential for human brain mapping, as well as in the diagnostic imaging of brain diseases.

  1. Classification of nanoparticle diffusion processes in vital cells by a multifeature random forests approach: application to simulated data, darkfield, and confocal laser scanning microscopy

    NASA Astrophysics Data System (ADS)

    Wagner, Thorsten; Kroll, Alexandra; Wiemann, Martin; Lipinski, Hans-Gerd

    2016-04-01

    Darkfield and confocal laser scanning microscopy both allow for a simultaneous observation of live cells and single nanoparticles. Accordingly, a characterization of nanoparticle uptake and intracellular mobility appears possible within living cells. Single particle tracking makes it possible to characterize the particle and the surrounding cell. In case of free diffusion, the mean squared displacement for each trajectory of a nanoparticle can be measured which allows computing the corresponding diffusion coefficient and, if desired, converting it into the hydrodynamic diameter using the Stokes-Einstein equation and the viscosity of the fluid. However, within the more complex system of a cell's cytoplasm unrestrained diffusion is scarce and several other types of movements may occur. Thus, confined or anomalous diffusion (e.g. diffusion in porous media), active transport, and combinations thereof were described by several authors. To distinguish between these types of particle movement we developed an appropriate classification method, and simulated three types of particle motion in a 2D plane using a Monte Carlo approach: (1) normal diffusion, using random direction and step-length, (2) subdiffusion, using confinements like a reflective boundary with defined radius or reflective objects in the closer vicinity, and (3) superdiffusion, using a directed flow added to the normal diffusion. To simulate subdiffusion we devised a new method based on tracks of different length combined with equally probable obstacle interaction. Next we estimated the fractal dimension, elongation and the ratio of long-time / short-time diffusion coefficients. These features were used to train a random forests classification algorithm. The accuracy for simulated trajectories with 180 steps was 97% (95%-CI: 0.9481-0.9884). The balanced accuracy was 94%, 99% and 98% for normal-, sub- and superdiffusion, respectively. Nanoparticle tracking analysis was used with 100 nm polystyrene particles

  2. High-speed multispectral confocal biomedical imaging

    PubMed Central

    Carver, Gary E.; Locknar, Sarah A.; Morrison, William A.; Krishnan Ramanujan, V.; Farkas, Daniel L.

    2014-01-01

    Abstract. A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues. PMID:24658777

  3. Crosswell seismic reflection/diffraction tomography: A reservoir characterization application

    SciTech Connect

    Tura, M.A.C. . Dept. of Earth Sciences); Greaves, R.J. . Earth Resources Lab.); Beydoun, W.B. )

    1994-03-01

    A crosswell seismic experiment at the San Emidio oil field in Bakersfield, California, is carried out to evaluate crosswell reflection/diffraction tomography and image the interwell region to locate a possible pinchout zone. In this experiment, the two wells used are 2,500 ft (762 m) apart, and the zone to be imaged is 11,000 ft (3,350 m) to 13,000 ft (3,960 m) deep. With the considered distances, this experiment forms the first large scale reservoir characterization application of crosswell reflection/diffraction tomography. A subset of the intended data, formed of two common receiver gathers and one common shot gather, was collected at the San Emidio oil field. The cross-well data display a wide variety of wave modes including tube waves, singly and multiply reflected/diffracted waves, and refracted waves. The data are processed using frequency filters, median filters, and spatial muting filters to enhance the reflected/diffracted energy. With the encouraging results obtained from synthetic data, the ERBMI method, with the smooth background velocity model is used next to image the processed field data. Images obtained from the crosswell data show a good match with the reflected field in the zero-offset VSPs and with migrated surface seismic data. From the interpretation of these images, the potential of this crosswell seismic method for answering questions regarding reservoir continuity and existence of pinchout zones can be seen.

  4. Shallow subsurface applications of high-resolution seismic reflection

    NASA Astrophysics Data System (ADS)

    Steeples, Don

    2002-11-01

    Shallow seismic reflection surveys have been applied to a wide variety of problems. For example, in many geologic settings, variations and discontinuities on the surface of bedrock can influence the transport and eventual fate of contaminants introduced at or near the ground surface. Using seismic methods to determine the nature and location of anomalous bedrock can be an essential component of hydrologic characterization. Shallow seismic surveys can also be used to detect earthquake faults and to image underground voids. During the early 1980s, the advent of digital engineering seismographs designed for shallow, high-resolution surveying spurred significant improvements in engineering and environmental reflection seismology. Commonly, shallow seismic reflection methods are used in conjunction with other geophysical and geological methods, supported by a well-planned drilling-verification effort. To the extent that seismic reflection, refraction, and surface-wave methods can constrain shallow stratigraphy, geologic structure, engineering properties, and relative permeability, these methods are useful in civil-engineering applications and in characterizing environmental sites. Case histories from Kansas, California, and Texas illustrate how seismic reflection can be used to map bedrock beneath alluvium at hazardous waste sites, detect abandoned coal mines, follow the top of the saturated zone during an alluvial aquifer pumping test, and map shallow faults that serve as contaminant flowpaths.

  5. Re-scan confocal microscopy: scanning twice for better resolution

    PubMed Central

    De Luca, Giulia M.R.; Breedijk, Ronald M.P.; Brandt, Rick A.J.; Zeelenberg, Christiaan H.C.; de Jong, Babette E.; Timmermans, Wendy; Azar, Leila Nahidi; Hoebe, Ron A.; Stallinga, Sjoerd; Manders, Erik M.M.

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity while maintaining the sectioning capability of a standard confocal microscope. This simple technology is typically useful for biological applications where the combination high-resolution and high-sensitivity is required. PMID:24298422

  6. Clinical applications of lightguide diffuse reflectance spectrophotometry in vascular disease

    NASA Astrophysics Data System (ADS)

    Harrison, David K.; Delaney, Colin; Brown, Linda; Newton, David J.; McCollum, Peter T.

    1994-02-01

    There is enormous potential for application of lightguide tissue reflectance spectrophotometry in the diagnosis and treatment of peripheral vascular disease. In the present study, measurements were carried out in 10 such pre-amputation patients to compare the use of micro-lightguide spectrophotometry with the macro-lightguide technique. These preliminary results show excellent agreement between the new, non-invasive micro-lightguide technique and the `gold standard' skin blood flow measurements. This technique could thus provide a more functional, non-invasive assessment of healing potential than skin blood flow measurement.

  7. Olivine-metal mixtures: Spectral reflectance properties and application to asteroid reflectance spectra

    NASA Astrophysics Data System (ADS)

    Cloutis, Edward A.; Sanchez, Juan A.; Reddy, Vishnu; Gaffey, Michael J.; Binzel, Richard P.; Burbine, Thomas H.; Hardersen, Paul S.; Hiroi, Takahiro; Lucey, Paul G.; Sunshine, Jessica M.; Tait, Kimberly T.

    2015-05-01

    Olivine-rich asteroids appear to be common in the main asteroid belt as well as present in the near-Earth asteroid population. There are a number of meteorite classes that are dominated by olivine ± metal. To determine whether relationships exist between these asteroids and meteorites, we spectrally characterized a number of olivine + meteoritic metal powder intimate and areal mixtures, pallasite slabs, and olivine powders on a metal slab. Our goal is to understand the spectral characteristics of olivine + metal assemblages and develop spectral metrics that can be used to analyze reflectance spectra of olivine-dominated asteroids. We found that the major olivine absorption band in the 1 μm region is resolvable in intimate mixtures for metal abundances as high as ∼90 wt.%. The wavelength position of the 1 μm region olivine absorption band center is sensitive to Fa content but insensitive to other variables. However, the band minimum position moves to shorter wavelengths with increasing metal abundance due to changes in spectral slope. The full width at half maximum (FWHM) of this band and reflectance at 1.8 μm are both most sensitive to olivine Fa content, metal abundance, and grain size, and much less to the presence of nanophase iron that reddens spectra. Reflectance at 0.56 μm and the 1.8/0.56 μm reflectance ratio are sensitive to these same parameters as well as to nanophase iron-associated spectral reddening. The wavelength position of the local reflectance maximum in the 0.7 μm region moves to longer wavelengths with increasing metal abundance and is most useful for constraining metal abundance in high metal-content mixtures. Pallasite slab spectra differ in a number of respects from powdered assemblages and multiple spectral parameters can be used to discriminate them. The spectra of increasingly fine-grained olivine + metal assemblages and those involving low-Fa olivine show increasing spectral dominance by metal. Systematic application of multiple

  8. Laser data transmission with the application of reflectance modulator

    NASA Astrophysics Data System (ADS)

    Knysak, Piotr; Mierczyk, Zygmunt; Zygmunt, Marek; Wojtanowski, Jacek; Traczyk, Maciej

    2016-12-01

    The article presents the main aspects related to the development of nonconventional asymmetric laser data transmission system. It describes the principle of data transmission in both the direction away from the laser transmitter, wherein a pulse position modulation is used, and in the opposite direction, where the modulation of the reflected radiation is performed. The results presented in the article confirm the possibility of using the described technology in the civilian area for monitoring and telemetry, where devices without radiation sources are taken into account. In military applications, the system can be used to identify own objects and forces on the battlefield by the application of pulsed laser rangefinders which are currently a standard battle equipment.

  9. Novel design for a confocal endoscope

    NASA Astrophysics Data System (ADS)

    Pillers, Russell B.; Publicover, Nelson G.

    2006-02-01

    Confocal imaging in an endoscopic format is currently under-utilized as a clinical investigative tool. This is due mainly to the complex, sensitive and costly scanning systems required to produce images. We hypothesize that design potential exists for an endoscope without any type of scanning system and that consequently can simultaneously acquire an entire confocal image frame. Our design exploits the parallel structure of fiber-optic image guides to eliminate all scanning hardware. The design is based upon developing a novel method to form a miniscule aperture on the end of each fiber in an image bundle. This process creates out-of-focus light rejection space between each fiber without changing the fiber spacing or the original outer diameter of the image guide. Our modified image guide can then be incorporated into an essentially typical endoscopic system. Using parallel apertures, a confocal endoscope or "conscope" can acquire images at a rate limited only by light intensity and the acquisition rate of a camera. The research presented in this paper shows the effects of adjusting pinhole diameter on confocal performance. The marriage of endoscopes, confocal imaging, parallel optical fibers, and the conscope design offers life science an ability to quickly observe deep, in-vivo cellular structures in their natural state. Although originally intended for endoscope applications, our design may benefit other forms of microscopy as well.

  10. Tunable fiber confocal sensor with LED

    NASA Astrophysics Data System (ADS)

    Weng, Chun-Jen; Lan, Tzu-Hsien; Hwang, Chi-Hung; Chu, Nien-Nan; Huang, Chien-Yao; Cheng, Pi-Ying

    2015-07-01

    A novel concept of confocal sensor based on focal lens is proposed to measure the displacement. The light source is a stabilized fiber coupled LED. A 1x2 graded-index multimode fiber optic coupler is used in this sensor. One port is a LED input port via SMA connector, another port is a LED output port connected to a reflective collimator and the other port is a reflective sensor port connected to a photo detector. The focusing sensor head is the cascade of a focal lens and a 20X objective lens. In this confocal displacement sensor, LED passes through a focal lens and an objective lens so that the LED beam focuses at a fixed focal point. A test target is placed after the objective lens. The displacement between the sensor head and a target can be measured quickly by detecting the reflective power according to the confocal principle. The long-term stability of LED is under 0.5%. The effective back focal length is varied from 5.67mm to 6.57mm by 0-290mA current driving so that the measuring range is about 0.9mm. The FWHM resolution of displacement is about 50μm. This sensor has the features of low cost, high stability, high precision and compact.

  11. Bidirectional Reflectance Functions for Application to Earth Radiation Budget Studies

    NASA Technical Reports Server (NTRS)

    Manalo-Smith, N.; Tiwari, S. N.; Smith, G. L.

    1997-01-01

    Reflected solar radiative fluxes emerging for the Earth's top of the atmosphere are inferred from satellite broadband radiance measurements by applying bidirectional reflectance functions (BDRFs) to account for the anisotropy of the radiation field. BDRF's are dependent upon the viewing geometry (i.e. solar zenith angle, view zenith angle, and relative azimuth angle), the amount and type of cloud cover, the condition of the intervening atmosphere, and the reflectance characteristics of the underlying surface. A set of operational Earth Radiation Budget Experiment (ERBE) BDRFs is available which was developed from the Nimbus 7 ERB (Earth Radiation Budget) scanner data for a three-angle grid system, An improved set of bidirectional reflectance is required for mission planning and data analysis of future earth radiation budget instruments, such as the Clouds and Earth's Radiant Energy System (CERES), and for the enhancement of existing radiation budget data products. This study presents an analytic expression for BDRFs formulated by applying a fit to the ERBE operational model tabulations. A set of model coefficients applicable to any viewing condition is computed for an overcast and a clear sky scene over four geographical surface types: ocean, land, snow, and desert, and partly cloudy scenes over ocean and land. The models are smooth in terms of the directional angles and adhere to the principle of reciprocity, i.e., they are invariant with respect to the interchange of the incoming and outgoing directional angles. The analytic BDRFs and the radiance standard deviations are compared with the operational ERBE models and validated with ERBE data. The clear ocean model is validated with Dlhopolsky's clear ocean model. Dlhopolsky developed a BDRF of higher angular resolution for clear sky ocean from ERBE radiances. Additionally, the effectiveness of the models accounting for anisotropy for various viewing directions is tested with the ERBE along tract data. An area

  12. Confocal coded aperture imaging

    DOEpatents

    Tobin, Jr., Kenneth William; Thomas, Jr., Clarence E.

    2001-01-01

    A method for imaging a target volume comprises the steps of: radiating a small bandwidth of energy toward the target volume; focusing the small bandwidth of energy into a beam; moving the target volume through a plurality of positions within the focused beam; collecting a beam of energy scattered from the target volume with a non-diffractive confocal coded aperture; generating a shadow image of said aperture from every point source of radiation in the target volume; and, reconstructing the shadow image into a 3-dimensional image of the every point source by mathematically correlating the shadow image with a digital or analog version of the coded aperture. The method can comprise the step of collecting the beam of energy scattered from the target volume with a Fresnel zone plate.

  13. Applications of microstructured silicon wafers as internal reflection elements in attenuated total reflection Fourier transform infrared spectroscopy.

    PubMed

    Schumacher, Henrik; Künzelmann, Ulrich; Vasilev, Boris; Eichhorn, Klaus-Jochen; Bartha, Johann W

    2010-09-01

    A novel internal reflection element (IRE) for attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectral acquisition is introduced and applied for several surface-sensitive measurements. It is based on microstructured double-side-polished (100) silicon wafers with v-shaped grooves of {111} facets on their backside. These facets of the so-called "microstructured single-reflection elements" (mSRE) are formed by a crystal-oriented anisotropic wet etching process within a conventional wafer structuring process. They are used to couple infrared radiation into and out of the IRE. In contrast to the application of the commonly used silicon multiple-reflection elements (MRE), the new elements provide single-reflection ATR measurements at the opposite wafer side by using simple reflection accessories without any special collimation. Due to the short light path, the spectral range covers the entire mid-infrared region with a high optical throughput, including the range of silicon lattice vibrations from 300 to 1500 cm(-1). In addition to typical ATR applications, i.e., the measurement of bulk liquids and soft materials, the new reflection elements can be effectively used and customer-specifically designed for in situ and ex situ investigations of aqueous solutions, thin films, and monolayers on Si. Examples presented in this article are in situ etching of native as well as thermal SiO(2) and characterization of polydimethylsiloxane (PDMS) films on Si under various measuring conditions.

  14. The design and construction of a cost-efficient confocal laser scanning microscope

    NASA Astrophysics Data System (ADS)

    Xi, Peng; Rajwa, Bartlomiej; Jones, James T.; Robinson, J. Paul

    2007-03-01

    The optical dissection ability of confocal microscopy makes it a powerful tool for biological materials. However, the cost and complexity of confocal scanning laser microscopy hinders its wide application in education. We describe the construction of a simplified confocal scanning laser microscope and demonstrate three-dimensional projection based on cost-efficient commercial hardware, together with available open source software.

  15. Confocal microscopy and exfoliative cytology

    PubMed Central

    Reddy, Shyam Prasad; Ramani, Pratibha; Nainani, Purshotam

    2013-01-01

    Context: Early detection of potentially malignant lesions and invasive squamous-cell carcinoma in the oral cavity could be greatly improved through techniques that permit visualization of subtle cellular changes indicative of the neoplastic transformation process. One such technique is confocal microscopy. Combining rapidity with reliability, an innovative idea has been put forward using confocal microscope in exfoliative cytology. Aims: The main objective of this study was to assess confocal microscopy for cytological diagnosis and the results were compared with that of the standard PAP stain. Settings and Design: Confocal microscope, acridine orange (AO) stain, PAP (Papanicolaou) stain. The study was designed to assess confocal microscopy for cytological diagnosis. In the process, smears of patients with (clinically diagnosed and/or suspected) oral squamous cell carcinoma as well as those of controls (normal people) were stained with acridine orange and observed under confocal microscope. The results were compared with those of the standard PAP method. Materials and Methods: Samples of buccal mucosa smears from normal patients and squamous cell carcinoma patients were made, fixed in 100% alcohol, followed by AO staining. The corresponding set of smears was stained with PAP stain using rapid PAP stain kit. The results obtained were compared with those obtained with AO confocal microscopy. Results: The study had shown nuclear changes (malignant cells) in the smears of squamous cell carcinoma patients as increased intensity of fluorescence of the nucleus, when observed under confocal microscope. Acridine orange confocal microscopy showed good amount of sensitivity and specificity (93%) in identifying malignant cells in exfoliative cytological smears. Conclusion: Confocal microscopy was found to have good sensitivity in the identification of cancer (malignant) cells in exfoliative cytology, at par with the PAP method. The rapidity of processing and screening a

  16. The comet assay: Reflections on its development, evolution and applications.

    PubMed

    Singh, Narendra P

    2016-01-01

    The study of DNA damage and its repair is critical to our understanding of human aging and cancer. This review reflects on the development of a simple technique, now known as the comet assay, to study the accumulation of DNA damage and its repair. It describes my journey into aging research and the need for a method that sensitively quantifies DNA damage on a cell-by-cell basis and on a day-by-day basis. My inspirations, obstacles and successes on the path to developing this assay and improving its reliability and sensitivity are discussed. Recent modifications, applications, and the process of standardizing the technique are also described. What was once untried and unknown has become a technique used around the world for understanding and monitoring DNA damage. The comet assay's use has grown exponentially in the new millennium, as emphasis on studying biological phenomena at the single-cell level has increased. I and others have applied the technique across cell types (including germ cells) and species (including bacteria). As it enters new realms and gains clinical relevance, the comet assay may very well illuminate human aging and its prevention.

  17. Interference Confocal Microscope Integrated with Spatial Phase Shifter

    PubMed Central

    Wang, Weibo; Gu, Kang; You, Xiaoyu; Tan, Jiubin; Liu, Jian

    2016-01-01

    We present an interference confocal microscope (ICM) with a new single-body four-step simultaneous phase-shifter device designed to obtain high immunity to vibration. The proposed ICM combines the respective advantages of simultaneous phase shifting interferometry and bipolar differential confocal microscopy to obtain high axis resolution, large dynamic range, and reduce the sensitivity to vibration and reflectance disturbance seamlessly. A compact single body spatial phase shifter is added to capture four phase-shifted interference signals simultaneously without time delay and construct a stable and space-saving simplified interference confocal microscope system. The test result can be obtained by combining the interference phase response and the bipolar property of differential confocal microscopy without phase unwrapping. Experiments prove that the proposed microscope is capable of providing stable measurements with 1 nm of axial depth resolution for either low- or high-numerical aperture objective lenses. PMID:27563909

  18. In Vivo Confocal Microscopy in Chloroquine-Induced Keratopathy

    PubMed Central

    Paladini, Iacopo; Menchini, Ugo; Mencucci, Rita

    2013-01-01

    In vivo confocal microscopy is becoming a mandatory examination to study corneal abnormalities such as drug deposits in systemic disease. A female diagnosed with fibromyalgia on systemic chloroquine for 9 months presented for an ophthalmic examination. Confocal microscopy was performed using the Confoscan 4 (Nidek Co. Ltd., Gamagori, Japan) and multiple highly reflective deposits in the epithelial basal cells were found, that were consistent with choloquine. Deposits were also present in the wing cell layer. In the anterior stroma these deposits were rare. Atypically shaped and branched nerves were also present in the anterior stroma. Corneal deposits of chloroquine can be evaluated by confocal microscopy. Confocal microscopy provides information on corneal metabolism and physiology. Chloroquine keratopathy can affect the anterior stroma in addition to the epithelium. PMID:23580857

  19. Interference Confocal Microscope Integrated with Spatial Phase Shifter.

    PubMed

    Wang, Weibo; Gu, Kang; You, Xiaoyu; Tan, Jiubin; Liu, Jian

    2016-08-24

    We present an interference confocal microscope (ICM) with a new single-body four-step simultaneous phase-shifter device designed to obtain high immunity to vibration. The proposed ICM combines the respective advantages of simultaneous phase shifting interferometry and bipolar differential confocal microscopy to obtain high axis resolution, large dynamic range, and reduce the sensitivity to vibration and reflectance disturbance seamlessly. A compact single body spatial phase shifter is added to capture four phase-shifted interference signals simultaneously without time delay and construct a stable and space-saving simplified interference confocal microscope system. The test result can be obtained by combining the interference phase response and the bipolar property of differential confocal microscopy without phase unwrapping. Experiments prove that the proposed microscope is capable of providing stable measurements with 1 nm of axial depth resolution for either low- or high-numerical aperture objective lenses.

  20. The role of confocal microscopy in the dermato-oncology practice.

    PubMed

    Diaconeasa, A; Boda, D; Neagu, M; Constantin, C; Căruntu, C; Vlădău, L; Guţu, D

    2011-01-01

    Reflectance-mode confocal microscopy (RCM) is a new in vivo skin imaging technique. We present our one-year experience in RCM examinations in skin tumors and the retrospective analysis of patients enrolled in the Dermatological Department of 'N. Paulescu' Institute using the Fotofinder Dermoscope IIŴ for the dermatoscopy analysis and VivaScope 1500Ŵ for in vivo RCM. We established the rank of RCM in the complex algorithm of skin cancer diagnose, showing that the presented experience can open new possibilities to implement this automated image analyzing system in the routine practice. Our analyzed cases clearly showed that confocal microscopy, therefore, optical biopsy, could guide the clinician towards an accurate diagnosis before surgical removal. Moreover, we emphasized that the development of this technique increases the potential of future teledermatologic applications.

  1. Reflectance spectroscopy: quantitative analysis techniques for remote sensing applications.

    USGS Publications Warehouse

    Clark, R.N.; Roush, T.L.

    1984-01-01

    Several methods for the analysis of remotely sensed reflectance data are compared, including empirical methods and scattering theories, both of which are important for solving remote sensing problems. The concept of the photon mean path length and the implications for use in modeling reflectance spectra are presented.-from Authors

  2. Twin-photon confocal microscopy.

    PubMed

    Simon, D S; Sergienko, A V

    2010-10-11

    A recently introduced two-channel confocal microscope with correlated detection promises up to 50% improvement in transverse spatial resolution [Simon, Sergienko, Optics Express 18, 9765 (2010)] via the use of photon correlations. Here we achieve similar results in a different manner, introducing a triple-confocal correlated microscope which exploits the correlations present in optical parametric amplifiers. It is based on tight focusing of pump radiation onto a thin sample positioned in front of a nonlinear crystal, followed by coincidence detection of signal and idler photons, each focused onto a pinhole. This approach offers further resolution enhancement in confocal microscopy.

  3. Pigmented eccrine poroma: dermoscopic and confocal features

    PubMed Central

    Bombonato, Caterina; Piana, Simonetta; Moscarella, Elvira; Lallas, Aimillios; Argenziano, Giuseppe; Longo, Caterina

    2016-01-01

    Eccrine poroma is a rare benign adnexal tumor of epithelial cells originating from the terminal ductal portion of the sweat glands that is typically located on palms and soles, although other cutaneous sites can be affected [1]. It is usually nonpigmented even if there is a pigmented variant that corresponds to 17% of cases and it is usually underdiagnosed, since it is mistakenly confused with other pigmented tumors [2,3]. Dermoscopy and reflectance confocal microscopy (RCM) may assist in the correct diagnosis of this tumor. Herein, we report one case of pigmented eccrine poroma (PEP) that simulated clinically a cutaneous melanoma or a basal cell carcinoma. Dermoscopy and RCM excluded the possibilities of those two diagnoses; the overall confocal findings were suggestive for a benign epithelial tumor. Histology was fundamental to diagnose this lesion as a pigmented eccrine poroma. Even if the diagnosis of eccrine poroma remains histopathological still, as in this case report, noninvasive tools such as dermoscopy and RCM examinations can be of help to rule out the diagnosis of melanoma. Larger studies on this rare pigmented variant of eccrine poroma could shed new light on the identification of specific diagnostic dermoscopic and confocal features. PMID:27648386

  4. Assessing asymmetry using reflection and rotoinversion in biomedical engineering applications.

    PubMed

    Hill, Shannon; Franco-Sepulveda, Esteban; Komeili, Amin; Trovato, Alexandra; Parent, Eric; Hill, Doug; Lou, Edmond; Adeeb, Samer

    2014-05-01

    Symmetry is a trait that has been extensively reviewed, especially clinically, as an indication of ideal geometry and health. Many geometric symmetry assessment techniques rely on two-dimensional measurements that do not account for the three-dimensional nature of the object. In this article, two methods, reflection and a process termed rotoinversion, a combination of reflection and rotation, are presented as potential methods to assess an object's deviation from symmetry. With reflection, the geometric models are reflected about a calculated best plane of symmetry. With rotoinversion, the models are reflected about an arbitrary plane and then rigidly translated and rotated to best align the translated and original models. The methods give the same results for bilaterally symmetric objects, but different results for bilaterally and rotationally symmetric objects. The two methods are applied to assess asymmetry in adolescent idiopathic scoliosis torso geometric models, producing similar results. There was an angle of 0.408° between the normal to the plane of reflection from the reflection process and the normal from the rotoinversion process and average rotation of 0.067° from rotoinversion. The most appropriate method depends on the purpose of the symmetry assessment and must be determined on a case-by-case basis.

  5. Confocal microscopy in transmitted light

    NASA Astrophysics Data System (ADS)

    Dodt, Hans-Ulrich; Becker, Klaus

    2003-10-01

    We developed a confocal microscope for transmitted light to visualize fine details in phase objects like unstained biological specimens. The main difficulty of confocal microscopy in transmission is the alignment of illumination and detector pinholes. This alignment was achieved by using "electronic pinholes" on the detector side. As a first step, we were able to image cells in onion skin at greater depths and with higher resolution than by using conventional microscopy.

  6. Optical tweezers for confocal microscopy

    NASA Astrophysics Data System (ADS)

    Hoffmann, A.; Meyer zu Hörste, G.; Pilarczyk, G.; Monajembashi, S.; Uhl, V.; Greulich, K. O.

    2000-11-01

    In confocal laser scanning microscopes (CLSMs), lasers can be used for image formation as well as tools for the manipulation of microscopic objects. In the latter case, in addition to the imaging lasers, the light of an extra laser has to be focused into the object plane of the CLSM, for example as optical tweezers. Imaging as well as trapping by optical tweezers can be done using the same objective lens. In this case, z-sectioning for 3D imaging shifts the optical tweezers with the focal plane of the objective along the optical axis, so that a trapped object remains positioned in the focal plane. Consequently, 3D imaging of trapped objects is impossible without further measures. We present an experimental set-up keeping the axial trapping position of the optical tweezers at its intended position whilst the focal plane can be axially shifted over a distance of about 15 μm. It is based on fast-moving correctional optics synchronized with the objective movement. First examples of application are the 3D imaging of chloroplasts of Elodea densa (Canadian waterweed) in a vigorous cytoplasmic streaming and the displacement of zymogen granules in pancreatic cancer cells (AR42 J).

  7. Combined Confocal and Magnetic Resonance Microscopy

    SciTech Connect

    Wind, Robert A.; Majors, Paul D.; Minard, Kevin R.; Ackerman, Eric J.; Daly, Don S.; Holtom, Gary R.; Thrall, Brian D.; Weber, Thomas J.

    2002-05-12

    Confocal and magnetic resonance microscopy are both used to study live cells in a minimally invasive way. Both techniques provide complementary information. Therefore, by examining cells simultaneously with both methodologies, more detailed information is obtained than is possible with each of the microscopes individually. In this paper two configurations of a combined confocal and magnetic resonance microscope described. In both cases the sample compartment is part of a temperature regulated perfusion system. The first configuration is capable of studying large single cells or three-dimensional cell agglomerates, whereas with the second configuration monolayers of mammalian cells can be investigated . Combined images are shown of Xenopus laevis frog oocytes, model JB6 tumor spheroids, and a single layer of Chinese hamster ovary cells. Finally, potential applications of the combined microscope are discussed.

  8. Any Way You Slice It—A Comparison of Confocal Microscopy Techniques

    PubMed Central

    Jonkman, James

    2015-01-01

    The confocal fluorescence microscope has become a popular tool for life sciences researchers, primarily because of its ability to remove blur from outside of the focal plane of the image. Several different kinds of confocal microscopes have been developed, each with advantages and disadvantages. This article will cover the grid confocal, classic confocal laser-scanning microscope (CLSM), the resonant scanning-CLSM, and the spinning-disk confocal microscope. The way each microscope technique works, the best applications the technique is suited for, the limitations of the technique, and new developments for each technology will be presented. Researchers who have access to a range of different confocal microscopes (e.g., through a local core facility) should find this paper helpful for choosing the best confocal technology for specific imaging applications. Others with funding to purchase an instrument should find the article helpful in deciding which technology is ideal for their area of research. PMID:25802490

  9. A New Multichannel Spectral Imaging Laser Scanning Confocal Microscope

    PubMed Central

    Zhang, Yunhai; Hu, Bian; Dai, Yakang; Yang, Haomin; Huang, Wei; Xue, Xiaojun; Li, Fazhi; Zhang, Xin; Jiang, Chenyu; Gao, Fei; Chang, Jian

    2013-01-01

    We have developed a new multichannel spectral imaging laser scanning confocal microscope for effective detection of multiple fluorescent labeling in the research of biological tissues. In this paper, the design and key technologies of the system are introduced. Representative results on confocal imaging, 3-dimensional sectioning imaging, and spectral imaging are demonstrated. The results indicated that the system is applicable to multiple fluorescent labeling in biological experiments. PMID:23585775

  10. Confocal Raman microspectrometry: a vectorial electromagnetic treatment of the light focused and collected through a planar interface and its application to the study of a thin coating.

    PubMed

    Sourisseau, C; Maraval, P

    2003-11-01

    In-depth confocal Raman microspectrometry (CRM) studies through a planar interface between materials of mismatched refraction indices are known to be affected by a decrease of both the collected Raman intensity and the axial resolution as a function of the penetration depth. Following a previous model, which takes the refraction, diffraction, and spherical aberration effects into account when focusing a Gaussian incident laser beam with a high numerical aperture objective lens, a complete vectorial treatment of these phenomena is considered. It is demonstrated that off-axis refraction effects cannot be neglected and that the dimension of the confocal pinhole aperture plays a crucial role on the effective focal plane position and on the collection efficiency. We thus propose a more rigorous and complete approach to the problem, and we find a very good agreement between experimental and theoretical Raman intensity variations for a thick polyethylene sample as a function of the penetration depth. As compared with calculations where only refraction was considered, we confirm that the lengthening of the focus even for a large penetration depth is significantly reduced upon diffraction effects. As an illustrative example, the theoretical Raman responses for a thin coating of approximately 20 microns on a polymer substrate were investigated and compared to experimental results already published. Even though the interfacial region is spread over approximately 5-6 microns when using a 100x objective and a confocal pinhole of 200 microns diameter, it is definitively concluded that the apparent axial resolution is not drastically deteriorated with increasing depth and that the coating thickness may be directly estimated with a precision of approximately 1.0 micron (5%).

  11. Metasurface with Reconfigurable Reflection Phase for High-Power Microwave Applications (Briefing Charts)

    DTIC Science & Technology

    2014-06-25

    Metasurfaces with Reconfigurable Reflection Phase for High-Power Microwave Applications Kenneth L. Morgan, Clinton P. Scarborough, Micah D...TITLE AND SUBTITLE Metasurface with Reconfigurable Reflection Phase for High- Power Microwave Applications 5a. CONTRACT NUMBER 5b...Examples that demonstrate theoretical methods for extending the operating power levels of metasurface reflectarrays have been given •The proposed

  12. In vivo confocal imaging of the retina in animal models using scanning laser ophthalmoscopy.

    PubMed

    Seeliger, Mathias W; Beck, Susanne C; Pereyra-Muñoz, Naira; Dangel, Susann; Tsai, Jen-Yue; Luhmann, Ulrich F O; van de Pavert, Serge A; Wijnholds, Jan; Samardzija, Marijana; Wenzel, Andreas; Zrenner, Eberhart; Narfström, Kristina; Fahl, Edda; Tanimoto, Naoyuki; Acar, Niyazi; Tonagel, Felix

    2005-12-01

    Scanning-laser ophthalmoscopy is a technique for confocal imaging of the eye in vivo. The use of lasers of different wavelengths allows to obtain information about specific tissues and layers due to their reflection and transmission characteristics. In addition, fluorescent dyes excitable in the blue and infrared range offer a unique access to the vascular structures associated with each layer. In animal models, a further enhancement in specificity can be obtained by GFP expression under control of tissue-specific promotors. Important fields of application are studies in retinal degenerations and the follow-up of therapeutic intervention.

  13. Further understanding of the adsorption mechanism of N719 sensitizer on anatase TiO2 films for DSSC applications using vibrational spectroscopy and confocal Raman imaging.

    PubMed

    Lee, Kee Eun; Gomez, Mario A; Elouatik, Samir; Demopoulos, George P

    2010-06-15

    Vibrational spectroscopic studies of N719 dye-adsorbed TiO(2) films have been carried out by using SERRS, ATR-FTIR, and confocal Raman imaging. The high wavenumber region (3000-4000 cm(-1)) of dye adsorbed TiO(2) is analyzed via Raman and IR spectroscopy to investigate the role of surface hydroxyl groups in the anchoring mode. As a complementary technique, confocal Raman imaging is employed to study the distribution features of key dye groups (COO-, bipyridine, and C=O) on the anatase surface. Sensitized TiO(2) films made from two different nanocrystalline anatase powders are investigated: a commercial one (Dyesol) and our synthetic variety produced through aqueous synthesis. It is proposed the binding of the N719 dye to TiO(2) to occur through two neighboring carboxylic acid/carboxylate groups via a combination of bidentate-bridging and H-bonding involving a donating group from the N719 (and/or Ti-OH) units and acceptor from the Ti-OH (and/or N719) groups. The Raman imaging distribution of COO(-)(sym) on TiO(2) was used to show the covalent bonding, while the distribution of C=O mode was applied to observe the electrostatically bonded groups.

  14. In vivo/ex vivo targeting of Langerhans cells after topical application of the immune response modifier TMX-202: confocal Raman microscopy and histology analysis

    NASA Astrophysics Data System (ADS)

    Darvin, Maxim E.; Thiede, Gisela; Ascencio, Saul Mujica; Schanzer, Sabine; Richter, Heike; Vinzón, Sabrina E.; Hasche, Daniel; Rösl, Frank; May, Roberto; Hazot, Yohan; Tamarkin, Dov; Lademann, Juergen

    2016-05-01

    The increased ability of TMX-202 (derivative of imiquimod) to penetrate the intact stratum corneum (SC) and the follicular orifices of porcine ear skin was shown ex vivo using confocal Raman microscopy and laser scanning microscopy. Moreover, to assess whether TMX-202 is able to reach the immune cells, Langerhans cells extracted from pretreated human skin were investigated ex vivo using confocal Raman microscopy combined with multivariate statistical methods. Tracking the Raman peak of dimethyl sulfoxide centered at 690 cm-1, the absorption of TMX-202 containing formulation by Langerhans cells was shown. To answer the question whether the TMX-202 active ingredient is able to reach Langerhans cells, the attraction of immune cells to TMX-202 containing formulation treated skin was measured in the in vivo rodent model Mastomys coucha. The results show that TMX-202 active ingredient is able to reach Langerhans cells after penetrating through the intact skin and subsequently attract immune cells. Both the intercellular/transcellular as well as the follicular pathways allow the penetration through the intact barrier of the SC.

  15. Rapid observation of unfixed, unstained human skin biopsy specimens with confocal microscopy and visualization

    NASA Astrophysics Data System (ADS)

    Masters, Barry R.; Aziz, David J.; Gmitro, Arthur F.; Kerr, James H.; O'Grady, Terence C.; Goldman, Leon

    1997-10-01

    The use of reflected light confocal microscopy is proposed to rapidly observe unfixed, unstained biopsy specimens of human skin. Reflected light laser scanning confocal microscopy was used to compare a freshly excised, unfixed, unstained biopsy specimen, and in vivo human skin. Optical sections from the ex vivo biopsy specimen of human skin and in vivo human skin were converted to red-green anaglyphs for 3D visualization. Contrast was derived from intrinsic differences in the scattering properties of the organelles and cells within the tissue. Individual cellular layers were observed in both tissues from the surface to the papillary dermis. Confocal microscopy of an unfixed, unstained biopsy specimen showed cells and cell nuclei of the stratum spinosum. Confocal microscopy of in vivo human skin demonstrated optical sectioning through a hair shaft on the upper hand. The combination of reflected light confocal microscopy and 3D visualization with red-green anaglyphs provides a rapid technique for observing fresh biopsies of human skin.

  16. Instrumentation for Reflectance Spectroscopy and Microspectroscopy with Application to Astrobiology

    NASA Technical Reports Server (NTRS)

    Mouroulis, Pantazis; Blaney, Diana L.; Green, Robert O.

    2008-01-01

    We present instrument concepts for in-situ reflectance spectroscopy over a spatial resolution range from several meters to tens of micrometers. These have been adapted to the low mass and power requirements of rover or similar platforms. Described are a miniaturized imaging spectrometer for rover mast, a combined mast and arm point spectrometer, and an imaging microspectrometer for the rover arm.

  17. Pre-therapy: the application of contact reflections.

    PubMed

    Prouty, Garry

    2007-01-01

    Contact Reflections are the primary method of Pre-Therapy. There are five formalized techniques: situational, facial, word-for-word, body, and reiterative. Together they form a web of psychological contact enabling the development of therapeutic relationships. A case history of treatment with a client with retardation and psychosis is presented with a discussion of the therapist's innovative technique.

  18. Confocal Microscopy and Molecular-Specific Optical Contrast Agents for the Detection of Oral Neoplasia

    PubMed Central

    Carlson, Alicia L.; Gillenwater, Ann M.; Williams, Michelle D.; El-Naggar, Adel K.; Richards-Kortum, R. R.

    2009-01-01

    Using current clinical diagnostic techniques, it is difficult to visualize tumor morphology and architecture at the cellular level, which is necessary for diagnostic localization of pathologic lesions. Optical imaging techniques have the potential to address this clinical need by providing real-time, sub-cellular resolution images. This paper describes the use of dual mode confocal microscopy and optical molecular-specific contrast agents to image tissue architecture, cellular morphology, and sub-cellular molecular features of normal and neoplastic oral tissues. Fresh tissue slices were prepared from 33 biopsies of clinically normal and abnormal oral mucosa obtained from 14 patients. Reflectance confocal images were acquired after the application of 6% acetic acid, and fluorescence confocal images were acquired after the application of a fluorescence contrast agent targeting the epidermal growth factor receptor (EGFR). The dual imaging modes provided images similar to light microscopy of hematoxylin and eosin and immunohistochemistry staining, but from thick fresh tissue slices. Reflectance images provided information on the architecture of the tissue and the cellular morphology. The nuclear-to-cytoplasmic (N/C) ratio from the reflectance images was at least 7.5 times greater for the carcinoma than the corresponding normal samples, except for one case of highly keratinized carcinoma. Separation of carcinoma from normal and mild dysplasia was achieved using this ratio (p<0.01). Fluorescence images of EGFR expression yielded a mean fluorescence labeling intensity (FLI) that was at least 2.7 times higher for severe dysplasia and carcinoma samples than for the corresponding normal sample, and could be used to distinguish carcinoma from normal and mild dysplasia (p<0.01). Analyzed together, the N/C ratio and the mean FLI may improve the ability to distinguish carcinoma from normal squamous epithelium. PMID:17877424

  19. Application of multispectral reflectance for early detection of tomato disease

    NASA Astrophysics Data System (ADS)

    Xu, Huirong; Zhu, Shengpan; Ying, Yibin; Jiang, Huanyu

    2006-10-01

    Automatic diagnosis of plant disease is important for plant management and environmental preservation in the future. The objective of this study is to use multispectral reflectance measurements to make an early discrimination between the healthy and infected plants by the strain of tobacco mosaic virus (TMV-U1) infection. There were reflectance changes in the visible (VIS) and near infrared spectroscopy (NIR) between the healthy and infected plants. Discriminant models were developed using discriminant partial least squares (DPLS) and Mahalanobis distance (MD). The DPLS models had a root mean square error of calibration (RMSEC) of 0.397 and correlation coefficient (r) of 0.59 and the MD model correctly classified 86.7% healthy plants and up to 91.7% infected plants.

  20. Application of acoustic reflection tomography to sonar imaging.

    PubMed

    Ferguson, Brian G; Wyber, Ron J

    2005-05-01

    Computer-aided tomography is a technique for providing a two-dimensional cross-sectional view of a three-dimensional object through the digital processing of many one-dimensional views (or projections) taken at different look directions. In acoustic reflection tomography, insonifying the object and then recording the backscattered signal provides the projection information for a given look direction (or aspect angle). Processing the projection information for all possible aspect angles enables an image to be reconstructed that represents the two-dimensional spatial distribution of the object's acoustic reflectivity function when projected on the imaging plane. The shape of an idealized object, which is an elliptical cylinder, is reconstructed by applying standard backprojection, Radon transform inversion (using both convolution and filtered backprojections), and direct Fourier inversion to simulated projection data. The relative merits of the various reconstruction algorithms are assessed and the resulting shape estimates compared. For bandpass sonar data, however, the wave number components of the acoustic reflectivity function that are outside the passband are absent. This leads to the consideration of image reconstruction for bandpass data. Tomographic image reconstruction is applied to real data collected with an ultra-wideband sonar transducer to form high-resolution acoustic images of various underwater objects when the sonar and object are widely separated.

  1. Short-pulsed diode lasers as an excitation source for time-resolved fluorescence applications and confocal laser scanning microscopy in PDT

    NASA Astrophysics Data System (ADS)

    Kress, Matthias; Meier, Thomas H.; El-Tayeb, Tarek A. A.; Kemkemer, Ralf; Steiner, Rudolf W.; Rueck, Angelika C.

    2001-11-01

    This article describes a setup for subcellular time-resolved fluorescence spectroscopy and fluorescence lifetime measurements using a confocal laser scanning microscope in combination with a short pulsed diode laser for fluorescence excitation and specimen illumination. The diode laser emits pulses at 398 nm wavelength with 70 ps full width at half maximum (FWHM) duration. The diode laser can be run at a pulse repetition rate of 40 MHz down to single shot mode. For time resolved spectroscopy a spectrometer setup consisting of an Czerny Turner spectrometer and a MCP-gated and -intensified CCD camera was used. Subcellular fluorescence lifetime measurements were achieved using a time-correlated single photon counting (TCSPC) module instead of the spectrometer setup. The capability of the short pulsed diode laser for fluorescence imaging, fluorescence lifetime measurements and time-resolved spectroscopy in combination with laser scanning microscopy is demonstrated by fluorescence analysis of several photosensitizers on a single cell level.

  2. Laboratory laser reflectance measurement and applications to asteroid surface analysis

    NASA Astrophysics Data System (ADS)

    Shaw, A.; Daly, M. G.; Cloutis, E. A.; Tait, K. T.; Izawa, M. R. M.; Barnouin, O. S.; Hyde, B. C.; Nicklin, I.

    2014-07-01

    Introduction Laboratory reflectance measurement of asteroid analogs is an important tool for interpreting the reflectance of asteroids. One dominant factor affecting how measured reflectance changes as a function of phase angle (180° minus the scattering angle) is surface roughness [1], which is related to grain size. A major goal of this study is to be able to use the angular distributions (phase functions) of scattered light from various regions on an asteroid surface to determine the relative grain size between those regions. Grain size affects the spectral albedo and continuum slopes of surface materials, has implications in terms of understanding geologic processes on asteroids and is also valuable for the planning and operations of upcoming missions to asteroids, such as the New Frontiers OSIRIS-REx sample return mission to the asteroid (101955) Bennu [2]. Information on surface roughness is particularly powerful when combined with other datasets, such as thermal inertia maps (e.g., a smooth, low-backscatter surface of low thermal inertia likely contains fine grains). Approach To better constrain the composition and surface texture of Bennu, we are conducting experiments to investigate the laser return signature of terrestrial and meteorite analogs to Bennu. The objective is to understand the nature of laser returns given possible compositional, grain size and slope distributions on the surface of Bennu to allow surface characterization, particularly surface grain size, which would significantly aid efforts to identify suitable sites for sampling by the OSIRIS-REx mission. Setup A 1064-nm laser is used to determine the reflectance of Bennu analogs and their constituents (1064 nm is the wavelength of many laser altimeters including the one planned to fly on OSIRIS-REx). Samples of interest include serpentinites (greenalite, etc.), magnetite, and shungite. To perform the experiments, a goniometer has been built. This instrument allows reflectance measurements

  3. Simple fiber-optic confocal microscopy with nanoscale depth resolution beyond the diffraction barrier.

    PubMed

    Ilev, Ilko; Waynant, Ronald; Gannot, Israel; Gandjbakhche, Amir

    2007-09-01

    A novel fiber-optic confocal approach for ultrahigh depth-resolution (confocal microscope approach that is compatible with a differential confocal microscope technique. To improve the dynamic range of the resolving laser power and to achieve a high resolution in the nanometric range, we have designed a simple apertureless reflection confocal microscope with a highly sensitive single-mode-fiber confocal output. The fiber-optic design is an effective alternative to conventional pinhole-based confocal systems and offers a number of advantages in terms of spatial resolution, flexibility, miniaturization, and scanning potential. Furthermore, the design is compatible with the differential confocal pinhole microscope based on the use of the sharp diffraction-free slope of the axial confocal response curve rather than the area around the maximum of that curve. Combining the advantages of ultrahigh-resolution fiber-optic confocal microscopy, we can work beyond the diffraction barrier in the subwavelength (below 200 nm) nanometric range exploiting confocal nanobioimaging of single cell and intracellular analytes.

  4. Effects of Reflection Category and Reflection Quality on Learning Outcomes during Web-Based Portfolio Assessment Process: A Case Study of High School Students in Computer Application Course

    ERIC Educational Resources Information Center

    Chou, Pao-Nan; Chang, Chi-Cheng

    2011-01-01

    This study examines the effects of reflection category and reflection quality on learning outcomes during Web-based portfolio assessment process. Experimental subjects consist of forty-five eight-grade students in a "Computer Application" course. Through the Web-based portfolio assessment system, these students write reflection, and join…

  5. The Application of Reflected GPS Signals to Ocean Remote Sensing

    NASA Technical Reports Server (NTRS)

    Garrison, James L.; Katzberg, Stephen J.

    1998-01-01

    The L-band broadcast signal from the Global Positioning System (GPS) which has reflected off of the sea surface is under study for use as a ocean, coastal and wetlands remote sensing tool. The reflected signal from a given GPS satellite is cross-correlated with the pseudorandom noise code uniquely identifying that satellite. The shape of this cross-correlation, ordinarily a very sharp triangle when tracking a direct line of sight signal, becomes wider and smoother as the mean square slope of the reflecting surface increases. It is proposed that the surface wind speed can be determined by matching the recorded shape of this cross-correlation to that predicted by theoretical models as a function of wind speed and direction. The significance of these effects increases with altitude of the receiver. Experimental data have been collected using a specially modified GPS receiver on aircraft and on a balloon at altitudes of up to 25 km. These data compare favorably with predictions of analytical models and demonstrate the dependence of the waveform shape on surface wind speed and receiver altitude. The advantages that this measurement technique has over conventional scatterometers is the small size, low cost and simplicity of the receiver hardware, no requirement for a transmitter, and the ability to simultaneously collect data from usually 10 or more points (from a low earth orbiting satellite). This number could if the Russian GLONASS (Global Navigation Satellite System) satellites are also considered as additional sources of radiation. Furthermore, the bistatic scattering geometry is complementary to the backscatter used by conventional scatterometers.

  6. Custom-made modification of a commercial confocal microscope to photolyze caged compounds using the conventional illumination module and its application to the observation of Inositol 1,4,5-trisphosphate-mediated calcium signals

    NASA Astrophysics Data System (ADS)

    Sigaut, Lorena; Barella, Mariano; Espada, Rocío; Ponce, María Laura; Dawson, Silvina Ponce

    2011-06-01

    The flash photolysis of ``caged'' compounds is a powerful experimental technique for producing rapid changes in concentrations of bioactive signaling molecules. These caged compounds are inactive and become active when illuminated with ultraviolet light. This paper describes an inexpensive adaptation of an Olympus confocal microscope that uses as source of ultraviolet light the mercury lamp that comes with the microscope for conventional fluorescence microscopy. The ultraviolet illumination from the lamp (350 - 400 nm) enters through an optical fiber that is coupled to a nonconventional port of the microscope. The modification allows to perform the photolysis of caged compounds over wide areas (~200 μm) and obtain confocal fluorescence images simultaneously. By controlling the ultraviolet illumination exposure time and intensity it is possible to regulate the amount of photolyzed compounds. In the paper we characterize the properties of the system and show its capabilities with experiments done in aqueous solution and in Xenopus Laevis oocytes. The latter demonstrate its applicability for the study of Inositol 1,4,5-trisphosphate-mediated intracellular calcium signals.

  7. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY

    EPA Science Inventory

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The goal of a CLSM is to acquire and quantify fluorescence and in some instruments acquire spectral characterization of emitted signals. The accuracy of these measurements demands that...

  8. Two-layer anti-reflection strategies for implant applications

    NASA Astrophysics Data System (ADS)

    Guerrero, Douglas J.; Smith, Tamara; Kato, Masakazu; Kimura, Shigeo; Enomoto, Tomoyuki

    2006-03-01

    A two-layer bottom anti-reflective coating (BARC) concept in which a layer that develops slowly is coated on top of a bottom layer that develops more rapidly was demonstrated. Development rate control was achieved by selection of crosslinker amount and BARC curing conditions. A single-layer BARC was compared with the two-layer BARC concept. The single-layer BARC does not clear out of 200-nm deep vias. When the slower developing single-layer BARC was coated on top of the faster developing layer, the vias were cleared. Lithographic evaluation of the two-layer BARC concept shows the same resolution advantages as the single-layer system. Planarization properties of a two-layer BARC system are better than for a single-layer system, when comparing the same total nominal thicknesses.

  9. Affine reflection groups for tiling applications: Knot theory and DNA

    NASA Astrophysics Data System (ADS)

    Bodner, M.; Patera, J.; Peterson, M.

    2012-01-01

    We present in this paper some non-conventional applications of affine Weyl groups Waff of rank 2, the symmetry group of the tiling/lattice. We first develop and present the tools for applications requiring tilings of a real Euclidean plane {R}^2. We then elucidate the equivalence of these tilings with 2D projections of knots. The resulting mathematical structure provides a framework within which is encompassed recent work utilizing knot theory for modeling the structure and function of genetic molecules, specifically the action of particular enzymes in altering the topology of DNA in site-specific recombination.

  10. Real-Time Confocal Imaging Of The Living Eye

    NASA Astrophysics Data System (ADS)

    Jester, James V.; Cavanagh, H. Dwight; Essepian, John; Shields, William J.; Lemp, Michael A.

    1989-12-01

    In 1986, we adapted the Tandem Scanning Reflected Light Microscope of Petran and Hadraysky to permit non-invasive, confocal imaging of the living eye in real-time. We were first to obtain stable, confocal optical sections in vivo, from human and animal eyes. Using confocal imaging systems we have now studied living, normal volunteers, rabbits, cats and primates sequentially, non-invasively, and in real-time. The continued development of real-time confocal imaging systems will unlock the door to a new field of cell biology involving for the first time the study of dynamic cellular processes in living organ systems. Towards this end we have concentrated our initial studies on three areas (1) evaluation of confocal microscope systems for real-time image acquisition, (2) studies of the living normal cornea (epithelium, stroma, endothelium) in human and other species; and (3) sequential wound-healing responses in the cornea in single animals to lamellar-keratectomy injury (cellular migration, inflammation, scarring). We believe that this instrument represents an important, new paradigm for research in cell biology and pathology and that it will fundamentally alter all experimental and clinical approaches in future years.

  11. Use of probe-based confocal laser endomicroscopy (pCLE) in gastrointestinal applications. A consensus report based on clinical evidence

    PubMed Central

    Wang, Kenneth K; Carr-Locke, David L; Singh, Satish K; Neumann, Helmut; Bertani, Helga; Arsenescu, Razvan I; Caillol, Fabrice; Chang, Kenneth J; Chaussade, Stanislas; Coron, Emmanuel; Costamagna, Guido; Dlugosz, Aldona; Ian Gan, S; Giovannini, Marc; Gress, Frank G; Haluszka, Oleh; Ho, Khek Y; Kahaleh, Michel; Konda, Vani J; Prat, Frederic; Shah, Raj J; Sharma, Prateek; Slivka, Adam; Wolfsen, Herbert C; Zfass, Alvin

    2015-01-01

    Background Probe-based confocal laser endomicroscopy (pCLE) provides microscopic imaging during an endoscopic procedure. Its introduction as a standard modality in gastroenterology has brought significant progress in management strategies, affecting many aspects of clinical care and requiring standardisation of practice and training. Objective This study aimed to provide guidance on the standardisation of its practice and training in Barrett’s oesophagus, biliary strictures, colorectal lesions and inflammatory bowel diseases. Methods Initial statements were developed by five group leaders, based on the available clinical evidence. These statements were then voted and edited by the 26 participants, using a modified Delphi approach. After two rounds of votes, statements were validated if the threshold of agreement was higher than 75%. Results Twenty-six experts participated and, among a total of 77 statements, 61 were adopted (79%) and 16 were rejected (21%). The adoption of each statement was justified by the grade of evidence. Conclusion pCLE should be used to enhance the diagnostic arsenal in the evaluation of these indications, by providing microscopic information which improves the diagnostic performance of the physician. In order actually to implement this technology in the clinical routine, and to ensure good practice, standardised initial and continuing institutional training programmes should be established. PMID:26137298

  12. Application of 3D reflection seismic methods to mineral exploration

    NASA Astrophysics Data System (ADS)

    Urosevic, Milovan

    2013-04-01

    Seismic exploration for mineral deposits is often tested by excessively complex structures, regolith heterogeneity, intrinsically low signal to noise ratio, ground relief and accessibility. In brown fields, where the majority of the seismic surveys have been conducted, existing infrastructure, old pits and tailings, heavy machinery in operation, mine drainage and other mine related activities are further challenging the application of seismic methods and furthermore increasing its cost. It is therefore not surprising that the mining industry has been reluctant to use seismic methods, particularly 3D for mineral exploration, primarily due to the high cost, but also because of variable performance, and in some cases ambiguous interpretation results. However, shallow mineral reserves are becoming depleted and exploration is moving towards deeper targets. Seismic methods will be more important for deeper investigations and may become the primary exploration tool in the near future. The big issue is if we have an appropriate seismic "strategy" for exploration of deep, complex mineral reserves. From the existing case histories worldwide we know that massive ore deposits (VMS, VHMS) constitute the best case scenario for the application of 3D seismic. Direct targeting of massive ore bodies from seismic has been documented in several case histories. Sediment hosted deposits could, in some cases, can also produce a detectable seismic signature. Other deposit types such as IOCG and skarn are much more challenging for the application of seismic methods. The complexity of these deposits requires new thinking. Several 3D surveys acquired over different deposit types will be presented and discussed.

  13. Measurement and application of bidirectional reflectance distribution function

    NASA Astrophysics Data System (ADS)

    Liao, Fei; Li, Lin; Lu, Chengwen

    2016-10-01

    When a beam of light with certain intensity and distribution reaches the surface of a material, the distribution of the diffused light is related to the incident angle, the receiving angle, the wavelength of the light and the types of the material. Bidirectional Reflectance Distribution Function (BRDF) is a method to describe this distribution. For an optical system, the optical and mechanical materials' BRDF are unique, and if we want to calculate stray light of the system we should know the correct BRDF data of the whole materials. There are fundamental significances in the area of space remote sensor where BRDF is needed in the precise radiation calibration. It is also important in the military field where BRDF can be used in the object identification and target tracking, etc. In this paper, 11 kinds of aerospace materials' BRDF are measured and more than 310,000 groups of BRDF data are achieved , and also a BRDF database is established in China for the first time. With the BRDF data of the database, we can create the detector model, build the stray light radiation surface model in the stray light analysis software. In this way, the stray radiation on the detector can be calculated correctly.

  14. Diffuse reflectance spectroscopy: towards clinical application in breast cancer.

    PubMed

    Evers, Daniel J; Nachabe, Rami; Vranken Peeters, Marie-Jeanne; van der Hage, Jos A; Oldenburg, Hester S; Rutgers, Emiel J; Lucassen, Gerald W; Hendriks, Benno H W; Wesseling, Jelle; Ruers, Theo J M

    2013-01-01

    Diffuse reflectance spectroscopy (DRS) is a promising new technique for breast cancer diagnosis. However, inter-patient variation due to breast tissue heterogeneity may interfere with the accuracy of this technique. To tackle this issue, we aim to determine the diagnostic accuracy of DRS in individual patients. With this approach, DRS measurements of normal breast tissue in every individual patient are directly compared with measurements of the suspected malignant tissue. Breast tissue from 47 female patients was analysed ex vivo by DRS. A total of 1,073 optical spectra were collected. These spectra were analyzed for each patient individually as well as for all patients collectively and results were compared to the pathology analyses. Collective patient data analysis for discrimination between normal and malignant breast tissue resulted in a sensitivity of 90 %, a specificity of 88 %, and an overall accuracy of 89 %. In the individual analyses all measurements per patient were categorized as either benign or malignant. The discriminative accuracy of these individual analyses was nearly 100 %. The diagnosis was classified as uncertain in only one patient. Based on the results presented in this study, we conclude that the analysis of optical characteristics of different tissue classes within the breast of a single patient is superior to an analysis using the results of a cohort data analysis. When integrated into a biopsy device, our results demonstrate that DRS may have the potential to improve the diagnostic workflow in breast cancer.

  15. Benefits of metal reflective surfaces for concentrating solar applications

    NASA Astrophysics Data System (ADS)

    Braendle, Stefan

    2010-08-01

    Concentrating photovoltaic (CPV) companies are constantly making gains in efficiency and a lower levelized cost of energy, but continue to face questions of reliability and efficiency at scale remain. New technologies such as highly efficient aluminum mirrors help CPV companies fulfill both of these demands by allowing for performance and reliability gains, while also enabling high volume production for scaled deployment. In testing, metal mirrors have shown to be good matches for concentrating applications while performing at the same level as glass mirrors in accelerated weather tests. When combined with the inherent lighter weight and formability of aluminum, these new mirrors provide CPV solutions with a compelling advantage in the field.

  16. Automated cellular pathology in noninvasive confocal microscopy

    NASA Astrophysics Data System (ADS)

    Ting, Monica; Krueger, James; Gareau, Daniel

    2014-03-01

    A computer algorithm was developed to automatically identify and count melanocytes and keratinocytes in 3D reflectance confocal microscopy (RCM) images of the skin. Computerized pathology increases our understanding and enables prevention of superficial spreading melanoma (SSM). Machine learning involved looking at the images to measure the size of cells through a 2-D Fourier transform and developing an appropriate mask with the erf() function to model the cells. Implementation involved processing the images to identify cells whose image segments provided the least difference when subtracted from the mask. With further simplification of the algorithm, the program may be directly implemented on the RCM images to indicate the presence of keratinocytes in seconds and to quantify the keratinocytes size in the en face plane as a function of depth. Using this system, the algorithm can identify any irregularities in maturation and differentiation of keratinocytes, thereby signaling the possible presence of cancer.

  17. Optical Electronic Bragg Reflection Sensor System with Hydrodynamic Flow Applications

    NASA Technical Reports Server (NTRS)

    Lyons, D. R.

    2003-01-01

    This project, as described in the following report, involved design and fabrication of fiber optic sensors for the detection and measurement of dynamic fluid density variations. These devices are created using UV (ultraviolet) ablation and generally modified transverse holographic fiber grating techniques. The resulting phase gratings created on or immediately underneath the flat portion of D-shaped optical waveguides are characterized as evanescent field sensing devices. The primary applications include the sensor portion of a real-time localized or distributed measurement system for hydrodynamic flow, fluid density measurements, and phase change phenomena. Several design modifications were implemented in an attempt to accomplish the tasks specified in our original proposal. In addition, we have established key collaborative relationships with numerous people and institutions.

  18. Time-resolved confocal fluorescence microscopy: novel technical features and applications for FLIM, FRET and FCS using a sophisticated data acquisition concept in TCSPC

    NASA Astrophysics Data System (ADS)

    Koberling, Felix; Krämer, Benedikt; Kapusta, Peter; Patting, Matthias; Wahl, Michael; Erdmann, Rainer

    2007-05-01

    In recent years time-resolved fluorescence measurement and analysis techniques became a standard in single molecule microscopy. However, considering the equipment and experimental implementation they are typically still an add-on and offer only limited possibilities to study the mutual dependencies with common intensity and spectral information. In contrast, we are using a specially designed instrument with an unrestricted photon data acquisition approach which allows to store spatial, temporal, spectral and intensity information in a generalized format preserving the full experimental information. This format allows us not only to easily study dependencies between various fluorescence parameters but also to use, for example, the photon arrival time for sorting and weighting the detected photons to improve the significance in common FCS and FRET analysis schemes. The power of this approach will be demonstrated for different techniques: In FCS experiments the concentration determination accuracy can be easily improved by a simple time-gated photon analysis to suppress the fast decaying background signal. A more detailed analysis of the arrival times allows even to separate FCS curves for species which differ in their fluorescence lifetime but, for example, cannot be distinguished spectrally. In multichromophoric systems like a photonic wire which undergoes unidirectional multistep FRET the lifetime information complements significantly the intensity based analysis and helps to assign the respective FRET partners. Moreover, together with pulsed excitation the time-correlated analysis enables directly to take advantage of alternating multi-colour laser excitation. This pulsed interleaved excitation (PIE) can be used to identify and rule out inactive FRET molecules which cause interfering artefacts in standard FRET efficiency analysis. We used a piezo scanner based confocal microscope with compact picosecond diode lasers as excitation sources. The timing performance

  19. Optimization of In Vivo Confocal Autofluorescence Imaging of the Ocular Fundus in Mice and Its Application to Models of Human Retinal Degeneration

    PubMed Central

    Issa, Peter Charbel; Singh, Mandeep S.; Lipinski, Daniel M.; Chong, Ngaihang V.; Delori, François C.; Barnard, Alun R.; MacLaren, Robert E.

    2012-01-01

    Purpose. To investigate the feasibility and to identify sources of experimental variability of quantitative and qualitative fundus autofluorescence (AF) assessment in mice. Methods. Blue (488 nm) and near-infrared (790 nm) fundus AF imaging was performed in various mouse strains and disease models (129S2, C57Bl/6, Abca4−/−, C3H-Pde6brd1/rd1, Rho−/−, and BALB/c mice) using a commercially available scanning laser ophthalmoscope. Gray-level analysis was used to explore factors influencing fundus AF measurements. Results. A contact lens avoided cataract development and resulted in consistent fundus AF recordings. Fundus illumination and magnification were sensitive to changes of the camera position. Standardized adjustment of the recorded confocal plane and consideration of the pupil area allowed reproducible recording of fundus AF from the retinal pigment epithelium with an intersession coefficient of repeatability of ±22%. Photopigment bleaching occurred during the first 1.5 seconds of exposure to 488 nm blue light (∼10 mW/cm2), resulting in an increase of fundus AF. In addition, there was a slight decrease in fundus AF during prolonged blue light exposure. Fundus AF at 488 nm was low in animals with an absence of a normal visual cycle, and high in BALB/c and Abca4−/− mice. Degenerative alterations in Pde6brd1/rd1 and Rho−/− were reminiscent of findings in human retinal disease. Conclusions. Investigation of retinal phenotypes in mice is possible in vivo using standardized fundus AF imaging. Correlation with postmortem analysis is likely to lead to further understanding of human disease phenotypes and of retinal degenerations in general. Fundus AF imaging may be useful as an outcome measure in preclinical trials, such as for monitoring effects aimed at lowering lipofuscin accumulation in the retinal pigment epithelium. PMID:22169101

  20. Application of Kubelka-Munk theory of diffuse reflectance to geologic problems - The role of scattering

    NASA Technical Reports Server (NTRS)

    Morris, R. V.; Mendell, W. W.; Neely, S. C.

    1982-01-01

    An understanding of the reflectance spectra of scattering media is vital for the appropriate interpretation of the reflectance spectra of planetary surfaces. When the absorption coefficient (k) and the mean size of the scattering centers are small, the Kubelka-Munk (K-M) theory of diffuse reflectance is valid. Since small values of k are characteristic of a wide variety of geologically important materials over a significant range of wavelength, the K-M theory should be applicable to appropriate portions of the reflectance spectra of these media if the dimensions of the scattering centers are sufficiently small. To test the utility of the K-M theory, a comparison is conducted of a set of theoretically generated spectra with a set of independently measured experimental spectra. The similarities found in the behavior of the two sets of spectra demonstrate the applicability of the K-M theory to the understanding of physical phenomena. Aspects of wavelength-dependent scattering are investigated.

  1. Confocal Raman microspectroscopy of the skin.

    PubMed

    Förster, Matthias; Bolzinger, Marie-Alexandrine; Montagnac, Gilles; Briançon, Stéphanie

    2011-01-01

    Confocal Raman spectroscopy is a technique with considerable potential for the non-invasive study of biological tissues and skin samples in vitro or in vivo. It can be used to study skin physiology and possible pathological conditions and to obtain data about molecular composition and the structure of skin, for example, water content, moisturization and changes in the skin barrier function can all be observed. In-depth measurements also allow biopharmaceutical studies, such as analyzing the rate of penetration of a drug and the biochemical changes that may be induced by an applied formulation. Confocal Raman microspectroscopy is now at such a stage of refinement that it opens up new vistas. The big leap forward in its ease of use enables this technology to be used as an analytical method by more and more non-specialist laboratories. This review gives an overview of the state of the art of this technology by presenting an update on the principles of Raman spectroscopy and then by looking at examples of new developments in in vivo and in vitro applications.

  2. The relaxed confocal scanning laser ophthalmoscope.

    PubMed

    Van de Velde, F J

    2006-01-01

    The development of the Scanning Laser Ophthalmoscope is reviewed from a historical perspective. Since a flying-spot scanning principle for an electro-optical ophthalmoscope was first disclosed in 1950, enabling milestones have included the introduction of the laser and inversion of the usual Gullstrand's configuration of optical pupils in 1977, and the application of the optical principle of confocality by means of double or de-scanning in 1983. As a result, high resolution and high contrast confocal infra-red ophthalmoscopy with a 790 nm diode laser, at video rates, is a major novel imaging modality when compared to traditional optical techniques. This imaging mode is ideal to provide the necessary fiducial landmarks for microperimetry, therapeutic laser and SD-OCT based optical sectioning of the retina. DPSS or He-Ne lasers emitting at 532, 543, 561 or 575 nm are used for complimentary red-free fundus imaging. The diode 790 nm and DPSS 490 nm lasers are also used for fluorescence excitation.

  3. Cross-polarization confocal imaging of subsurface flaws in silicon nitride.

    SciTech Connect

    Liu, Z.; Sun, J. G.; Pei, Z.

    2011-03-01

    A cross-polarization confocal microscopy (CPCM) method was developed to image subsurface flaws in optically translucent silicon nitride (Si{sub 3}N{sub 4}) ceramics. Unlike conventional confocal microscopy, which measures reflected light so is applicable only to transparent and semi-transparent materials, CPCM detects scattered light from subsurface while filtering out the reflected light from ceramic surface. For subsurface imaging, the refractive-index mismatch between imaging (air) and imaged (ceramic) medium may cause image distortion and reduce resolution in the depth direction. This effect, characterized by an axial scaling factor (ASF), was analyzed and experimentally determined for glass and Si{sub 3}N{sub 4} materials. The experimental CPCM system was used to image Hertzian C-cracks generated by various indentation loads in the subsurface of a Si{sub 3}N{sub 4} specimen. It was demonstrated that CPCM may provide detailed information of subsurface cracks, such as crack angle and path, and subsurface microstructural variations.

  4. Frames-Based Denoising in 3D Confocal Microscopy Imaging.

    PubMed

    Konstantinidis, Ioannis; Santamaria-Pang, Alberto; Kakadiaris, Ioannis

    2005-01-01

    In this paper, we propose a novel denoising method for 3D confocal microscopy data based on robust edge detection. Our approach relies on the construction of a non-separable frame system in 3D that incorporates the Sobel operator in dual spatial directions. This multidirectional set of digital filters is capable of robustly detecting edge information by ensemble thresholding of the filtered data. We demonstrate the application of our method to both synthetic and real confocal microscopy data by comparing it to denoising methods based on separable 3D wavelets and 3D median filtering, and report very encouraging results.

  5. Simple method for modeling radar reflections in a homogeneous halfspace, with applications

    NASA Astrophysics Data System (ADS)

    Greenfield, Roy J.; Moran, Mark L.; Davis, J. L.

    2000-04-01

    We have developed a method to rapidly compute synthetic radar records from complex reflecting surfaces. The approach is a 3- D time domain Hemholtz-Kirchhoff (HK) representation, similar to Hilterman (1981), that includes the radiation characteristics of GPR dipoles on the surface of a uniform dielectric halfspace. Validity is established by making comparisons with published model results and by comparisons with field data. Comparison to the ray theory results of Zeng et al. (1997) show excellent agreement in reflection arrival times for pipes of various diameters. We also reproduce the non-specular reflection results of Schleicher et al. (1991), which show that large amplitude reflections can originate from the inflection points of curved surfaces. Our comparisons with field data use reflection records taken at a test site in Borden, Ontario, over horizontally oriented buried metal drums. The H-plane reflection data were collected using shielded 700-MHz dipoles. Our raw synthetic amplitude trends show reasonable agreement to the field data, but are not perfect. Using a small diameter synthetic dipole array, we show that the mismatch is most likely caused by antenna shielding effects. The versatility of the HK method is demonstrated by giving results for a number of interesting applications. These include synthetic records for crisscrossing pipes buried at various depths, reflection synthetics from a truncated cone representing the slag heaps in Daniels and Brower (1998), and reflections from a rough surface. The slag heap models demonstrate the effect of antenna polarization on reflections from sloping surfaces. Analysis of synthetic reflections from rough surfaces shows that the coda following the first impulsive arrival can be used to estimate the surface roughness. This is of interest for interpreting reflections from glacier data. Our results demonstrate that the HK method is useful in interpreting data, as well as for developing field survey strategies.

  6. Enlightening the Pink: Use of Confocal Microscopy in Pink Lesions.

    PubMed

    Gill, Melissa; González, Salvador

    2016-10-01

    Solitary pink lesions can pose a particular challenge to dermatologists because they may be almost or completely featureless clinically and dermoscopically, previously requiring biopsy to exclude malignancy. However, these lesions usually are not particularly challenging histopathologically. Thus, the incorporation of in vivo reflectance confocal microscopy into the clinical practice, which allows for noninvasive examination of the skin at the cellular level revealing features previously seen only on histopathology, is particularly useful for this subset of clinically difficult lesions.

  7. Automated Confocal Microscope Bias Correction

    NASA Astrophysics Data System (ADS)

    Dorval, Thierry; Genovesio, Auguste

    2006-10-01

    Illumination artifacts systematically occur in 2D cross-section confocal microscopy imaging . These bias can strongly corrupt an higher level image processing such as a segmentation, a fluorescence evaluation or even a pattern extraction/recognition. This paper presents a new fully automated bias correction methodology based on large image database preprocessing. This method is very appropriate to the High Content Screening (HCS), method dedicated to drugs discovery. Our method assumes that the amount of pictures available is large enough to allow a reliable statistical computation of an average bias image. A relevant segmentation evaluation protocol and experimental results validate our correction algorithm by outperforming object extraction on non corrupted images.

  8. Confocal fluctuation spectroscopy and imaging.

    PubMed

    Földes-Papp, Zeno; Liao, Shih-Chu Jeff; You, Tiefeng; Terpetschnig, Ewald; Barbieri, Beniamino

    2010-09-01

    Currently, work with subnanomolar concentrations is routine while femtomolar and even single-molecule studies are possible with some efforts getting high on single-molecule biophysics and biochemistry. Methodological breakthroughs, such as reducing the background light contribution in single-molecule studies, which has plagued many studies of molecular fluorescence in dilute solution, and particularly in live cells, have recently described by us. We first demonstrated how optimized time-gating of the fluorescence signal, together with time-correlated, single-photon counting, can be used to substantially boost the experimental signal-to-noise ratio about 140-fold, making it possible to measure analyte concentrations that are as low as 15 pM. By detection of femtomolar bulk concentrations, confocal microsopy has the potential to address the observation of one and the same molecule in dilute solution without immobilization or hydrodynamic/electrokinetic focusing at longer observation times than currently available. We present relevant physics. The equations are derived using Einstein's approach showing how it fits with Fick's law and the autocorrelation function. An improved technology is being developed at ISS for femtomolar microscopy. The general concepts and provided experimental examples should help to compare our approach to those used in conventional confocal microscopy.

  9. Polarization-based index of refraction and reflection angle estimation for remote sensing applications.

    PubMed

    Thilak, Vimal; Voelz, David G; Creusere, Charles D

    2007-10-20

    A passive-polarization-based imaging system records the polarization state of light reflected by objects that are illuminated with an unpolarized and generally uncontrolled source. Such systems can be useful in many remote sensing applications including target detection, object segmentation, and material classification. We present a method to jointly estimate the complex index of refraction and the reflection angle (reflected zenith angle) of a target from multiple measurements collected by a passive polarimeter. An expression for the degree of polarization is derived from the microfacet polarimetric bidirectional reflectance model for the case of scattering in the plane of incidence. Using this expression, we develop a nonlinear least-squares estimation algorithm for extracting an apparent index of refraction and the reflection angle from a set of polarization measurements collected from multiple source positions. Computer simulation results show that the estimation accuracy generally improves with an increasing number of source position measurements. Laboratory results indicate that the proposed method is effective for recovering the reflection angle and that the estimated index of refraction provides a feature vector that is robust to the reflection angle.

  10. Intravital Confocal and Two-photon Imaging of Dual-color Cells and Extracellular Matrix Mimics

    PubMed Central

    Bal, Ufuk; Andresen, Volker; Baggett, Brenda; Utzinger, Urs

    2013-01-01

    To optimize imaging of cells in three dimensional culture we studied confocal backscattering, Second Harmonic Generation (SHG) and autofluorescence as source of contrast in extracellular matrix (ECM) mimics and evaluated the attenuation as well as bleaching of endogenous cellular fluorescence signals. All common ECM mimics exhibit contrast observable with confocal reflectance microscopy. SHG imaging on collagen I based hydrogels provides high contrast and good optical penetration depth. Agarose is a useful embedding medium because it allows for large optical penetration and exhibits minimal autofluorescence while still providing good reflectance to detect voids in the embedding medium. We labeled breast cancer cells’ outline with DsRed2 and nucleus with eGFP. DsRed2 can be excited with confocal imaging at 568nm, and with two photon excitation (TPE) in the red and longer NIR. eGFP was excited at 488nm for confocal and in the NIR for TPE. While there is small difference in the bleaching rate for eGFP between confocal and TPE we observed significant difference for DsRed2 where bleaching is strongest during TPE in the red wavelengths and smallest during confocal imaging. After a few hundred microns depth in a collagen I hydrogel, TPE fluorescence becomes twice as strong compared to confocal imaging. PMID:23380006

  11. Applications of high power lasers. [using reflection holograms for machining and surface treatment

    NASA Technical Reports Server (NTRS)

    Angus, J. C.

    1979-01-01

    The use of computer generated, reflection holograms in conjunction with high power lasers for precision machining of metals and ceramics was investigated. The Reflection holograms which were developed and made to work at both optical wavelength (He-Ne, 6328 A) and infrared (CO2, 10.6) meet the primary practical requirement of ruggedness and are relatively economical and simple to fabricate. The technology is sufficiently advanced now so that reflection holography could indeed be used as a practical manufacturing device in certain applications requiring low power densities. However, the present holograms are energy inefficient and much of the laser power is lost in the zero order spot and higher diffraction orders. Improvements of laser machining over conventional methods are discussed and addition applications are listed. Possible uses in the electronics industry include drilling holes in printed circuit boards making soldered connections, and resistor trimming.

  12. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    NASA Astrophysics Data System (ADS)

    Dhara, Sangita; Misra, N. L.; Maind, S. D.; Kumar, Sanjukta A.; Chattopadhyay, N.; Aggarwal, S. K.

    2010-02-01

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 μL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO 3/HClO 4, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1 σ) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

  13. Evaluating hybrid bermudagrass using spectral reflectance under different mowing heights and trinexapac-ethyl applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative spectral reflectance data has the potential to improve the evaluation of turfgrass variety trials when management practices are factors in the testing of turf aesthetics and functionality. However, the practical application of this methodology has not been well-developed. The objectives...

  14. "Knowing Is Not Enough; We Must Apply": Reflections on a Failed Action Learning Application

    ERIC Educational Resources Information Center

    Reese, Simon

    2015-01-01

    This paper reflects upon a sub-optimal action learning application with a strategic business re-design project. The objective of the project was to improve the long-term business performance of a subsidiary business and build the strategic plan. Action learning was introduced to aid the group in expanding their view of the real problems…

  15. Universal Design for Learning in Postsecondary Education: Reflections on Principles and their Application

    ERIC Educational Resources Information Center

    Rose, David H.; Harbour, Wendy S.; Johnston, Catherine Sam; Daley, Samantha G.; Abarbanell, Linda

    2006-01-01

    Authored by the teaching staff of T-560: Meeting the Challenge of Individual Differences at the Harvard Graduate School of Education, this article reflects on potential applications of universal design for learning (UDL) in university courses, illustrating major points with examples from T-560. The article explains the roots of UDL in cognitive…

  16. Promoting Reflective Thinking Skills by Using Web 2.0 Application

    ERIC Educational Resources Information Center

    Abdullah, Mohamed

    2015-01-01

    The study aims to investigate are using Web 2.0 applications promoting reflective thinking skills for higher education student in faculty for education. Although the literature reveals that technology integration is a trend in higher education and researchers and educators have increasingly shared their ideas and examples of implementations of Web…

  17. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: PRETTY PICTURES OR CONFOCAL QA

    EPA Science Inventory

    Evaluation of confocal microscopy system performance: Pretty pictures or confocal QA?

    Robert M. Zucker

    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, N...

  18. Confocal imaging of butterfly tissue.

    PubMed

    Brunetti, Craig R

    2014-01-01

    To understand the molecular events responsible for morphological change requires the ability to examine gene expression in a wide range of organisms in addition to model systems to determine how the differences in gene expression correlate with phenotypic differences. There are approximately 12,000 species of butterflies, most, with distinct patterns on their wings. The most important tool for studying gene expression in butterflies is confocal imaging of butterfly tissue by indirect immunofluorescence using either cross-reactive antibodies from closely related species such as Drosophila or developing butterfly-specific antibodies. In this report, we describe how indirect immunofluorescence protocols can be used to visualize protein expression patterns on the butterfly wing imaginal disc and butterfly embryo.

  19. Confocal endomicroscopy of the larynx

    NASA Astrophysics Data System (ADS)

    Just, T.; Wiechmann, T.; Stachs, O.; Stave, J.; Guthoff, R.; Hüttmann, G.; Pau, H. W.

    2012-02-01

    Beside the good image quality with the confocal laser scanning microscope (HRTII) and the Rostock Cornea Module (RCM), this technology can not be used to investigate the human larynx in vivo. To accomplish this, a rigid custom-made endoscope (KARL STORZ GmbH & Co. KG; Tuttlingen Germany) was developed. A connector was developed to connect the scanner head of the HRTII to the rigid endoscope. With the connector, the starting plane can be set manually. To achieve optical sectioning of the laryngeal tissue (80 μm per volume scan), the scanning mechanism of the HRTII needs to be activated using a foot switch. The devices consisting of the endoscope, HRTII, and the connector supply images of 400 x 400 μm and reach average penetration depths of 100-300 μm (λ/4 plate of the scanner head of the HRTII was removed). The lateral and axial resolutions are about 1-2 μm and 2 μm, respectively. In vivo rigid confocal endoscopy is demonstrated with an acquisition time for a volume scan of 6 s. The aim of this study was to differentiate pre-malignant laryngeal lesions from micro-invasive carcinoma of the larynx. 22 patients with suspicious lesions of the true vocal cords were included. This pilot study clearly demonstrates the possibility to detect dysplastic cells close to the basal cell layer and within the subepithelial space in lesions with small leukoplakia (thin keratin layer). These findings may have an impact on microlaryngoscopy to improve the precision for biopsy and on microlaryngoscopic laser surgery of the larynx to identify the margins of the pre-malignant lesion.

  20. Needle-based confocal laser endomicroscopy

    PubMed Central

    Giovannini, Marc

    2015-01-01

    New applications of confocal laser endomicroscopy were developed as pCLE in the bile duct and nCLE for pancreatic cystic tumors, pancreatic masses and lymph nodes. The aim of this paper would be to give you an update in this new technology and to try to define its place in the diagnosis of cystic and solid pancreatic masses. The material used was a 19G EUS-needle in which the stylet was replaced by the Confocal mini-probe. The mini-probe (0.632 mm of diameter) is pre-loaded and screwed by a locking device in the EUS-Needle and guided endosonographically in the target. Regarding pancreatic cystic lesion, the presence of epithelial villous structures based on nCLE was associated with pancreatic cystic neoplasm (IPMN) (P = 0.004) and provided a sensitivity of 59%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. A superficial vascular network pattern visualized on nCLE was identified in serous cystadenomas. It corresponded on pathological specimen to a dense and subepithelial capillary vascularization. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of this sign for the diagnosis of SCA were 87%, 69%, 100%, 100%, and 82%, respectively. In pancreatic adenocarcinomas, nCLE found vascular leakage with irregular vessels with leakage of fluorescein into the tumor, large dark clumps which correspond to humps of malignant cells. These criteria correlate with the histological structure of those tumors which are characterized by tumoral glands, surrounded by fibrosis in case of fibrous stroma tumor. Neuroendocrine tumors showed a dense network of small vessels on a dark background, which fits with the histological structure based on cord of cells surrounded by vessels and by fibrosis. nCLE is feasible during a EUS examination; these preliminary results are very encouraging and may be used in the future in case of inconclusive EUS-FNA. PMID:26643694

  1. Clinical feasibility of rapid confocal melanoma feature detection

    NASA Astrophysics Data System (ADS)

    Hennessy, Ricky; Jacques, Steve; Pellacani, Giovanni; Gareau, Daniel

    2010-02-01

    In vivo reflectance confocal microscopy shows promise for the early detection of malignant melanoma. One diagnostic trait of malignancy is the presence of pagetoid melanocytes in the epidermis. For automated detection of MM, this feature must be identified quantitatively through software. Beginning with in vivo, noninvasive confocal images from 10 unequivocal MMs and benign nevi, we developed a pattern recognition algorithm that automatically identified pagetoid melanocytes in all four MMs and identified none in five benign nevi. One data set was discarded due to artifacts caused by patient movement. With future work to bring the performance of this pattern recognition technique to the level of the clinicians on difficult lesions, melanoma diagnosis could be brought to primary care facilities and save many lives by improving early diagnosis.

  2. Multimodal confocal mosaicing microscopy: an emphasis on squamous cell carcinoma

    NASA Astrophysics Data System (ADS)

    Chen, Nathaniel W.; Sensibaugh, Jordan; Ardeshiri, Ardaland; Blanchard, Adam; Jacques, Steven; Gareau, Daniel

    2010-02-01

    Our previous study reported a sensitivity of 96.6% and a specificity of 89.2% in rapidly detecting Basal Cell Carcinomas (BCCs) when nuclei were stained with acridine orange. Squamous Cell Carcinomas (SCCs) and infiltrative BCCs remain difficult to detect. More complete screening can be achieved utilizing both acridine orange for nuclei staining and eosin for cytoplasmic contrast, using two lasers to excite the two stains independently. Nuclear fluorescence is achieved by staining with acridine orange (0.5mM, 60 s), and cytoplasmic fluorescence is achieved by staining with eosin working solution (30 s). This work shows good morphological contrast of SCC and infiltrative BCC with eosin, acridine orange, and reflectance, and presents a means for rapid SCC and infiltrative BCC detection in fresh skin excisions using multimodal confocal microscopy. In addition, digital staining is shown to effectively simulate hematoxylin and eosin (H&E) histology with confocal mosaics.

  3. Confocal Microscope Alignment of Nanocrystals for Coherent Diffraction Imaging

    NASA Astrophysics Data System (ADS)

    Beitra, Loren; Watari, Moyu; Matsuura, Takashi; Shimamoto, Naonobu; Harder, Ross; Robinson, Ian

    2010-06-01

    We have installed and tested an Olympus LEXT confocal microscope at the 34-ID-C beamline of the Advanced Photon Source (APS). The beamline is for Coherent X-ray Diffraction (CXD) experiments in which a nanometre-sized crystal is aligned inside a focussed X-ray beam. The microscope was required for three-dimensional (3D) sample alignment to get around sphere-of-confusion issues when locating Bragg peaks in reciprocal space. In this way, and by use of strategic sample preparations, we have succeeded in measuring six Bragg peaks from a single 200 nm gold crystal and obtained six projections of its internal displacement field. This enables the clear identification of stacking-fault bands within the crystal. The confocal alignment method will allow a full determination of the strain tensor provided three or more Bragg reflections from the same crystal are found.

  4. EVALUATION OF CONFOCAL MICROSCOPY SYSTEM PERFORMANCE

    EPA Science Inventory

    BACKGROUND. The confocal laser scanning microscope (CLSM) has enormous potential in many biological fields. Currently there is a subjective nature in the assessment of a confocal microscope's performance by primarily evaluating the system with a specific test slide provided by ea...

  5. Single-material multilayer ZnS as anti-reflective coating for solar cell applications

    NASA Astrophysics Data System (ADS)

    Salih, Ammar T.; Najim, Aus A.; Muhi, Malek A. H.; Gbashi, Kadhim R.

    2017-04-01

    Multilayer Zinc Sulfide (ZnS) is a promising low cost antireflective coating for solar cell applications, in this work; thin films with novel structure containing cubic and hexagonal phases were successfully deposited by thermal evaporation technique with three different layers. XRD analysis confirms the existence of both phases and high specific surface area. AFM analysis reveals that films with three layers have lower roughness and average grain size than other films. The optical measurements obtained by UV-vis, the calculated values of refractive index and reflectivity using some well known refractive index-band gap relations indicate that thin films with triple layer TL-ZnS have lower refractive index and reflectivity than other films, empirical equations were suggested and show the quantum confinement effects on band gap and reflectivity.

  6. Multiplanar OCT/confocal ophthalmoscope in the clinic

    NASA Astrophysics Data System (ADS)

    Rosen, Richard B.; Podoleanu, Adrian Gh.; Rogers, John A.; Dunne, Shane; Dobre, George M.; Cucu, Radu G.; Jackson, David A.; Garcia, Patricia; Orlock, Dennis A.; Yannuzzi, Lawrence A.; Fisher, Yale; Nieto, Juan; Gentile, Ronald C.; Rosenthal, Jeanne L.; Muldoona, Thomas O.; Walsh, Joseph B.; Costa, Danielle; Huang, Sheau; Slakter, Jason; Spaide, Richard

    2003-07-01

    This paper demonstrates the clinical application of a multiplanar imaging system, which simultaneously acquires en-face (C-scan) OCT and corresponding confocal ophthalmoscopic images along with cross-sectional (B-scan) OCT at cursor designated locations on the confocal image. Advantages of the simultaneous OCT/confocal acquisition as well as the challenges of interpreting the C-scan OCT images are discussed. Variations in tissue inclination with respect to th coherence wave surface alters the sampling of structures within the depth in the retina, producing novel slice orientations which are often challenging to interpret. We evaluate for the first time the utility of C-scan OCT for a variety of pathologies including exudative ARMD, macular hole, central serous retinopathy, diabetic retinopathy, polypoidal choroidal vasculopathy and macular pucker. Several remarkable observations of new aspects of clinical anatomy were noted. The versatility of selective capture of C-scan OCT images and B-scan OCT images at precise points on the confocal image affords the clinician a more complete and interactive tool for 3D imaging of retinal pathology.

  7. Performance of dual axes confocal microscope for in vivo molecular and cellular imaging

    NASA Astrophysics Data System (ADS)

    Kino, Gordon S.; Wang, Thomas D.; Contag, Chris H.; Mandella, Michael; Chan, Ning Y.

    2004-07-01

    The application of conventional confocal microscopes with high numerical aperture (NA) to in vivo imaging is limited by the objectiveís large physical dimensions and short working distance. We are developing a confocal microscope that uses simple low NA lenses oriented in a dual axes configuration for miniaturization and in vivo imaging. This architecture achieves a long working distance, micron level axial resolution, and reduced noise from scattered light outside the focal volume. Combined with the novel method of post-objective scanning, this design can be scaled down to millimeter dimensions. We derive the dual axes response from diffraction theory, and construct two tabletop prototypes to demonstrate the performance of this approach. We collect images from freshly excised biopsy specimens of human esophagus and transgenic mouse cerebellum expressing GFP. With horizontal cross-sectional images, we achieve 1 to 2 μm resolution and collect reflectance and fluorescence images. With vertical cross-sectional images, we achieve 4 to 5 μm resolution, dynamic range of 70 dB, and tissue penetration over 1 mm. An instrument miniaturized with this configuration could be used for in vivo cellular and molecular imaging.

  8. Measured energy savings from the application of reflective roofsin 2 small non-residential buildings

    SciTech Connect

    Akbari, Hashem

    2003-01-14

    Energy use and environmental parameters were monitored in two small (14.9 m{sup 2}) non-residential buildings during the summer of 2000. The buildings were initially monitored for about 1 1/2 months to establish a base condition. The roofs of the buildings were then painted with a white coating and the monitoring was continued. The original solar reflectivities of the roofs were about 26%; after the application of roof coatings the reflectivities increased to about 72%. The monitored electricity savings were about 0.5kWh per day (33 Wh/m2 per day). The estimated annual savings are about 125kWh per year (8.4 kWh/m2); at a cost of $0.1/kWh, savings are about $0.86/m2 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote locations of these buildings. However, since the prefabricated roofs are already painted green at the factory, painting them a white (reflective) color would bring no additional cost. Hence, a reflective roof saves energy at no incremental cost.

  9. Application of backward diffuse reflection spectroscopy for monitoring the state of tissues in photodynamic therapy

    SciTech Connect

    Stratonnikov, Aleksandr A; Meerovich, G A; Ryabova, A V; Savel'eva, T A; Loshchenov, V B

    2006-12-31

    The application of backward diffuse reflection (BDR) spectroscopy for in vivo monitoring the degree of haemoglobin oxygenation and concentration of photosensitisers in tissues subjected to photodynamic therapy is demonstrated. A simple experimental technique is proposed for measuring diffuse reflection spectra. The measurements are made under steady-state conditions using a fibreoptic probe with one transmitting and one receiving fibre separated by a fixed distance. Although this approach does not ensure the separation of contributions of scattering and absorption to the spectra being measured, it can be used for estimating the degree of haemoglobin oxygenation and concentration of photosensitisers in the tissues. Simple expressions for estimating the concentration of photosensitisers from the BDR spectra are presented and the accuracy of this approach is analysed. The results of application of BDR spectroscopy for monitoring various photosensitisers are considered. (special issue devoted to multiple radiation scattering in random media)

  10. Submillimeter Confocal Imaging Active Module

    NASA Technical Reports Server (NTRS)

    Hong, John; Mehdi, Imran; Siegel, Peter; Chattopadhyay, Goutam; Cwik, Thomas; Rowell, Mark; Hacker, John

    2009-01-01

    The term submillimeter confocal imaging active module (SCIAM) denotes a proposed airborne coherent imaging radar system that would be suitable for use in reconnaissance, surveillance, and navigation. The development of the SCIAM would include utilization and extension of recent achievements in monolithic microwave integrated circuits capable of operating at frequencies up to and beyond a nominal radio frequency of 340 GHz. Because the SCIAM would be primarily down-looking (in contradistinction to primarily side-looking), it could be useful for imaging shorter objects located between taller ones (for example, objects on streets between buildings). The SCIAM would utilize a confocal geometry to obtain high cross-track resolution, and would be amenable to synthetic-aperture processing of its output to obtain high along-track resolution. The SCIAM (see figure) would include multiple (two in the initial version) antenna apertures, separated from each other by a cross-track baseline of suitable length (e.g., 1.6 m). These apertures would both transmit the illuminating radar pulses and receive the returns. A common reference oscillator would generate a signal at a controllable frequency of (340 GHz + (Delta)f)/N, where (Delta)f is an instantaneous swept frequency difference and N is an integer. The output of this oscillator would be fed to a frequency- multiplier-and-power-amplifier module to obtain a signal, at 340 GHz + (Delta)f, that would serve as both the carrier signal for generating the transmitted pulses and a local-oscillator (LO) signal for a receiver associated with each antenna aperture. Because duplexers in the form of circulators or transmit/receive (T/R) switches would be lossy and extremely difficult to implement, the antenna apertures would be designed according to a spatial-diplexing scheme, in which signals would be coupled in and out via separate, adjacent transmitting and receiving feed horns. This scheme would cause the transmitted and received beams

  11. Studies in Confocal Scanning Optical Microscopy

    NASA Astrophysics Data System (ADS)

    Corle, Timothy Richard

    Optical microscopes have been used as measurement tools in many areas of science of the past 300 years. Despite their maturity, there is still active research in the field. In particular the development of confocal scanning optical microscopes (CSOMs) in the 1970's has extended the usefulness of optical microscopes by giving them depth imaging capabilities. In a CSOM a defocused image disappears rather than blurring as it does with a standard microscope. The shallow depth of focus allows structures with a height difference smaller than one wavelength to be imaged independently, and thus quantitative measurements of height can be made. The design and construction of two CSOMs is discussed. The first is a mechanically scanned single pinhole microscope. This instrument was developed as a test bed on which to try out ideas relating to phase contrast imaging. The second is a Nipkow disk based real-time confocal scanning optical microscope (RSOM). These two microscopes were used to investigate the transverse and depth resolution of CSOMs. It is demonstrated that although they do not intrinsically have any better transverse resolution than a standard optical microscope, CSOMs produce a visually sharper image with increased contrast. The depth response of the CSOM is also investigated. A vector theory for the depth response is derived and compared with experimental results. It is shown that previously unexplained asymmetries in the sidelobe structure of this response can be accounted for by aberrations in the microscope objective. Phase contrast images can be generated by periodically defocusing the microscope, either mechanically or electro -optically and detecting a signal at the modulation frequency. A new electro-optic phase contrast microscope is described. The microscope is used to quantitatively measure both the height and width of thin film gratings. The depth response and point spread function of this microscope are also derived. It is shown that the sidelobe

  12. Reflectance-based skin detection in the short wave infrared band and its application to video

    NASA Astrophysics Data System (ADS)

    Langston, Tye

    2016-10-01

    Robust reflectance-based skin detection is a potentially powerful tool for security and search and rescue applications, especially when applied to video. However, to be useful it must be able to account for the variations of human skin, as well as other items in the environment that could cause false detections. This effort focused on identifying a robust skin detection scheme that is appropriate for video application. Skin reflectance was modeled to identify unique skin features and compare them to potential false positive materials. Based on these comparisons, specific wavelength bands were selected and different combinations of two and three optical filters were used for actively identifying skin, as well as identifying and removing potential false positive materials. One wavelength combination (1072/1250 nm) was applied to video using both single- and dual-camera configurations based on its still image performance, as well as its appropriateness for video application. There are several important factors regarding the extension of still image skin detection to video, including light available for detection (solar irradiance and reflectance intensity), overall intensity differences between different optical filters, optical component light loss, frame rate, time lag when switching between filters, image coregistration, and camera auto gain behavior.

  13. Comparative evaluation of two simple diffuse reflectance models for biological tissue applications.

    PubMed

    Zonios, George; Bassukas, Ioannis; Dimou, Aikaterini

    2008-09-20

    We present a comparative evaluation of two simple diffuse reflectance models for biological tissue applications. One model is based on a widely accepted and used in biomedical optics implementation of diffusion theory, and the other one is based on a semiempirical approach derived from basic physical principles. We test the models on tissue phantoms and on human skin, utilizing a standard six-around-one optical fiber probe for light delivery and collection. We show that both models are suitable for use with an optical fiber probe and illustrate the potential, applicability, and validity range of the models.

  14. The design of broad band anti-reflection coatings for solar cell applications

    NASA Astrophysics Data System (ADS)

    Siva Rama Krishna, Angirekula; Sabat, Samrat Lagnajeet; Ghanashyam Krishna, Mamidipudi

    2017-01-01

    The design of broadband anti-reflection coatings (ARCs) for solar cell applications using multiobjective differential evolutionary (MODE) algorithms is reported. The effect of thickness and refractive index contrast within the layers of the ARC on the bandwidth of reflectance is investigated in detail. In the case of the hybrid plasmonic ARC structures the effect of size, shape and filling fraction of silver (Ag) nanoparticles on the reflectance is studied. Bandwidth is defined as the spectral region of wavelengths over which the reflectance is below 2%. Single, two and three layers ARCs (consisting of MgF2, Al2O3, Si3N4, TiO2 and ZnS or combinations of these materials) were simulated for performance evaluation on an a-Si photovoltaic cell. It is observed that the three layer ARC consisting of MgF2/Si3N4/TiO2(ZnTe) of 81/42/36 nm thicknesses, respectively, exhibited a weighted reflectance of 1.9% with a bandwidth of 450 nm over the wavelength range of 300-900 nm. The ARC bandwidth could be further improved by embedding randomly distributed Ag nanoparticles of size between 100 and 120 nm on a two layer ARC consisting of Al2O3/TiO2 with thickness of 42 nm and 56 nm respectively. This plasmon-dielectric hybrid ARC design exhibited a weighted reflectance of 0.6% with a bandwidth of 560 nm over the wavelength range of 300-900 nm.

  15. Measured Energy Savings from the Application of Reflective Roofs in 3 AT and T Regeneration Buildings

    SciTech Connect

    Akbari, Hashen; Rainer, Leo

    2000-11-01

    Energy use and environmental parameters were monitored in three AT and T regeneration buildings during the summer of 2000. These buildings are constructed with concrete and are about 14.9 m2 (160 f2; 10x16 ft)in size. The buildings were initially monitored for about 1 1/2 months to establish a base condition. Then, the roofs of the buildings were painted with a white coating and the monitoring was continued. The original roof reflectances were about 26 percent; after the application of roof coatings the reflectivities increased to about 72 percent. In two of these buildings, we monitored savings of about 0.5kWh per day (8.6 kWh/m2 [0.8 kWh/ft2]). The third building showed a reduction in air-conditioning energy use of about 13kWh per day. These savings probably resulted from the differences in the performance (EER) of the two dissimilar AC units in this building. The estimated annual savings for two of the buildings are about 125kWh per year; at a cost of dollar 0.1/kWh, savings are about dollar 12.5 per year. Obviously, it costs significantly more than this amount to coat the roofs with reflective coating, particularly because of the remote location of the buildings. However, since the prefabricated roofs are already painted green at the factory, painting them with white (reflective) color would bring no additional cost. Hence the payback time for having reflective roofs is nil, and the reflective roofs save an accumulated 370kWh over 30 years of the life of the roof.

  16. Live confocal imaging of Arabidopsis flower buds.

    PubMed

    Prunet, Nathanaël; Jack, Thomas P; Meyerowitz, Elliot M

    2016-11-01

    Recent advances in confocal microscopy, coupled with the development of numerous fluorescent reporters, provide us with a powerful tool to study the development of plants. Live confocal imaging has been used extensively to further our understanding of the mechanisms underlying the formation of roots, shoots and leaves. However, it has not been widely applied to flowers, partly because of specific challenges associated with the imaging of flower buds. Here, we describe how to prepare and grow shoot apices of Arabidopsis in vitro, to perform both single-point and time-lapse imaging of live, developing flower buds with either an upright or an inverted confocal microscope.

  17. Chromatic confocal microscope using hybrid aspheric diffractive lenses

    NASA Astrophysics Data System (ADS)

    Rayer, Mathieu; Mansfield, Daniel

    2014-05-01

    A chromatic confocal microscope is a single point non-contact distance measurement sensor. For three decades the vast majority of the chromatic confocal microscope use refractive-based lenses to code the measurement axis chromatically. However, such an approach is limiting the range of applications. In this paper the performance of refractive, diffractive and Hybrid aspheric diffractive are compared. Hybrid aspheric diffractive lenses combine the low geometric aberration of a diffractive lens with the high optical power of an aspheric lens. Hybrid aspheric diffractive lenses can reduce the number of elements in an imaging system significantly or create large hyper- chromatic lenses for sensing applications. In addition, diffractive lenses can improve the resolution and the dynamic range of a chromatic confocal microscope. However, to be suitable for commercial applications, the diffractive optical power must be significant. Therefore, manufacturing such lenses is a challenge. We show in this paper how a theoretical manufacturing model can demonstrate that the hybrid aspheric diffractive configuration with the best performances is achieved by step diffractive surface. The high optical quality of step diffractive surface is then demonstrated experimentally. Publisher's Note: This paper, originally published on 5/10/14, was replaced with a corrected/revised version on 5/19/14. If you downloaded the original PDF but are unable to access the revision, please contact SPIE Digital Library Customer Service for assistance.

  18. In vivo 783-channel diffuse reflectance imaging system and its application

    NASA Astrophysics Data System (ADS)

    Yang, Joon-Mo; Han, Yong-Hui; Yoon, Gilwon; Ahn, Byung Soo; Lee, Byung-Cheon; Soh, Kwang-Sup

    2007-08-01

    A fiber-based reflectance imaging system was constructed to produce in vivo absorption spectroscopic images of biological tissues with diffuse light in the cw domain. The principal part of this system is the 783-channel fiber probe, composed of 253 illumination fibers and 530 detection fibers distributed in a 20×20 mm square region. During illumination with the 253 illumination fibers, diffuse reflected lights are collected by the 530 detection fibers and recorded simultaneously as an image with an electron multiplying CCD camera for fast data acquisition. After signal acquisition, a diffuse reflectance image was reconstructed by applying the spectral normalization method we devised. To test the applicability of the spectral normalization, we conducted two phantom experiments with chicken breast tissue and white Delrin resin by using animal blood as an optical inhomogeneity. In the Delrin phantom experiment, we present images produced by two methods, spectral normalization and reference signal normalization, along with a comparison of the two. To show the feasibility of our system for biomedical applications, we took images of a human vein in vivo with the spectral normalization method.

  19. Big five personality traits reflected in job applicants' social media postings.

    PubMed

    Stoughton, J William; Thompson, Lori Foster; Meade, Adam W

    2013-11-01

    Job applicants and incumbents often use social media for personal communications allowing for direct observation of their social communications "unfiltered" for employer consumption. As such, these data offer a glimpse of employees in settings free from the impression management pressures present during evaluations conducted for applicant screening and research purposes. This study investigated whether job applicants' (N=175) personality characteristics are reflected in the content of their social media postings. Participant self-reported social media content related to (a) photos and text-based references to alcohol and drug use and (b) criticisms of superiors and peers (so-called "badmouthing" behavior) were compared to traditional personality assessments. Results indicated that extraverted candidates were prone to postings related to alcohol and drugs. Those low in agreeableness were particularly likely to engage in online badmouthing behaviors. Evidence concerning the relationships between conscientiousness and the outcomes of interest was mixed.

  20. Electromagnetic reflection and transmission at interfaces involving graded dielectrics with applications to planetary radar astronomy

    NASA Technical Reports Server (NTRS)

    Simpson, R. A.

    1976-01-01

    Reflection and transmission of electromagnetic waves at an interface between two homogeneous materials is modified when a transition zone of linearly increasing permittivity is inserted between the half spaces. Mathematical expressions for reflection and transmission coefficients are derived for waves at arbitrary incidence angles and polarized either in or perpendicular to the plane of incidence. Discontinuities in permittivity at the transition-zone boundaries are allowed. There is efficient transmission between the two half-spaces for transition-zone thicknesses of a wavelength or greater. For sharper changes, the matching layer has diminishing effect and the wave-interface interaction is characterized by the difference in properties between the two half-spaces. Examples applicable to lunar radar astronomy and airborne terrestrial remote sensing are used to illustrate the relationship between wavelength and thickness of the transition layer.

  1. Large Area Microencapsulated Reflective Guest-Host Liquid Crystal Displays and Their Applications

    NASA Astrophysics Data System (ADS)

    Nakai, Yutaka; Tanaka, Masao; Enomoto, Shintaro; Iwanaga, Hiroki; Hotta, Aira; Kobayashi, Hitoshi; Oka, Toshiyuki; Kizaki, Yukio; Kidzu, Yuko; Naito, Katsuyuki

    2002-07-01

    We have developed reflective liquid crystal displays using microencapsulated guest-host liquid crystals, whose size was sufficiently large for viewing documents. A high-brightness image can be realized because there is no need for polarizers. Easy fabrication processes, consisting of screen-printing of microencapsulated liquid crystal and film adhesion, have enabled the realization of thinner and lighter cell structures. It has been confirmed that the display is tolerant of the pressures to which it would be subject in actual use. The optimization of fabrication processes has enabled the realization of reflectance uniformity in the display area and reduction of the driving voltage. Our developed display is suitable for portable information systems, such as electronic book applications.

  2. Diffractive elements performance in chromatic confocal microscopy

    NASA Astrophysics Data System (ADS)

    Garzón, J.; Duque, D.; Alean, A.; Toledo, M.; Meneses, J.; Gharbi, T.

    2011-01-01

    The Confocal Laser Scanning Microscopy (CLSM) has been widely used in the semiconductor industry and biomedicine because of its depth discrimination capability. Subsequent to this technique has been developed in recent years Chromatic Confocal Microscopy. This method retains the same principle of confocal and offers the added advantage of removing the axial movement of the moving system. This advantage is usually accomplished with an optical element that generates a longitudinal chromatic aberration and a coding system that relates the axial position of each point of the sample with the wavelength that is focused on each. The present paper shows the performance of compact chromatic confocal microscope when some different diffractive elements are used for generation of longitudinal chromatic aberration. Diffractive elements, according to the process and manufacturing parameters, may have different diffraction efficiency and focus a specific wavelength in a specific focal position. The performance assessment is carried out with various light sources which exhibit an incoherent behaviour and a broad spectral width.

  3. Point scanning confocal microscopy facilitates 3D human hair follicle imaging in tissue sections.

    PubMed

    Kloepper, Jennifer E; Bíró, Tamás; Paus, Ralf; Cseresnyés, Zoltán

    2010-07-01

    Efficiency is a key factor in determining whether a scientific method becomes widely accepted in practical applications. In dermatology, morphological characterisation of intact hair follicles by traditional methods can be rather inefficient. Samples are embedded, sliced, imaged and digitally reconstructed, which can be time-consuming. Confocal microscopy, on the other hand, is more efficient and readily applicable to study intact hair follicles. Modern confocal microscopes deliver and collect light very efficiently and thus allow high spatial resolution imaging of relatively thick samples. In this letter, we report that we successfully imaged entire intact human hair follicles using point scanning confocal microscopy. Light delivery and light-collection were further improved by preparing the samples in 2,2'-Thiodiethanol (TDE), thus reducing refractive index gradients. The relatively short total scan times and the high quality of the acquired 3D images make confocal microscopy a desirable method for studying intact hair follicles under normal and pathological conditions.

  4. Confocal Raman Microspectroscopy of Oral Streptococci

    NASA Astrophysics Data System (ADS)

    Beier, Brooke D.

    Raman spectroscopy has been used in a variety of applications throughout the field of biomedical optics. It has the ability to acquire chemically-specific information in a non-invasive manner, without the need for exogenous markers. This makes it useful in the identification of bacterial species, as well as in the study of tissues and other cells. In this work, a species identification model has been created in order to discriminate between the oral bacterial species Streptococcus sanguinis and Streptococcus mutans. These are two of the most prevalent species within the human mouth and their relative concentrations can be an indicator of a patient's oral health and risk of tooth decay. They are predominantly found within plaque on the tooth's surface. To study a simplified model for dental plaque, we have examined S. sanguinis and S. mutans grown in biofilm forms. Raman spectroscopy has been implemented here through a confocal microscope. The optical system has been equipped with computationally controlled stages to allow for automated scanning, including autofocusing to probe a consistent depth within a sample. A spectrum has been acquired from each position within a scan and sent for spectral preprocessing before being submitted for species identification. This preprocessing includes an algorithm that has been developed to remove fluorescence features from known contaminants within the confocal volume, to include signal from a fluorescent substrate. Species classification has been accomplished using a principal component score-fed logistic regression model constructed from a variety of biofilm samples that have been transferred and allowed to dry, as might occur with the study of plaque samples. This binary classification model has been validated on other samples with identical preparations. The model has also been transferred to determine the species of hydrated biofilms studied in situ. Artificially mixed biofilms have been examined to test the spatial

  5. In vivo confocal microscopy of toxic keratopathy

    PubMed Central

    Chen, Y; Le, Q; Hong, J; Gong, L; Xu, J

    2017-01-01

    Purpose To explore the morphological characteristics of toxic keratopathy (TK), which clinically presented as superficial punctate keratopathy (SPK), with the application of in vivo laser-scanning confocal microscopy (LSCM), and evaluate its potential in the early diagnosis of TK. Patients and methods This was a cross-sectional study involving 16 patients with TK and 16 patients with dry eye (DE), demonstrating SPK under slit-lamp observation, and 10 normal eyes were enrolled in the study. All participants underwent history interviews, fluorescein staining, tear film break-up time (BUT) tests, Schirmer tests, and in vivo LSCM. Results The area grading of corneal fluorescein punctate staining was higher in the TK group than the DE group. Measured by in vivo LSCM, superficial epithelial cell density was lower in the TK group than that of DE group. The sub-basal nerve presented lower density and tortuosity in the TK group than the DE group. Most notably, deposits with a snow-like appearance were observed in the epithelium in 12/16 (75.0%) of the TK cases, but none in the DE group (P<0.05). Conclusion The SPK in TK patients was characterized by more widespread punctate staining, a lower density of superficial epithelial cells and sub-basal nerves, and a typical snow-like pattern of deposits in the epithelium by LSCM. These features might facilitate early diagnosis of TK from other disorders manifested as SPK. PMID:27740620

  6. Confocal microlaparoscope for imaging the fallopian tube

    NASA Astrophysics Data System (ADS)

    Wu, Tzu-Yu; Schafer, Rachel; Rouse, Andrew R.; Gmitro, Arthur F.

    2012-02-01

    Recent evidence suggests that epithelial ovarian cancer may originate in the fimbriated end of the fallopian tube1. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. We have previously reported on a rigid confocal microlaparoscope system that is currently undergoing a clinical trial to image the epithelial surface of the ovary2. In order to gain in vivo access to the fallopian tubes we have developed a new confocal microlaparoscope with an articulating distal tip. The new instrument builds upon the technology developed for the existing confocal microlaparoscope. It has an ergonomic handle fabricated by a rapid prototyping printer. While maintaining compatibility with a 5 mm trocar, the articulating distal tip of the instrument consists of a 2.2 mm diameter bare fiber bundle catheter with automated dye delivery for fluorescence imaging. This small and flexible catheter design should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Early ex vivo mages of human fallopian tube and in vivo imaging results from recent open surgeries using the rigid confocal microlaparoscope system are presented. Ex vivo images from animal models using the new articulating bare fiber system are also presented. These high quality images collected by the new flexible system are similar in quality to those obtained from the epithelial surface of ovaries with the rigid clinical confocal microlaparoscope.

  7. Modular Scanning Confocal Microscope with Digital Image Processing.

    PubMed

    Ye, Xianjun; McCluskey, Matthew D

    2016-01-01

    In conventional confocal microscopy, a physical pinhole is placed at the image plane prior to the detector to limit the observation volume. In this work, we present a modular design of a scanning confocal microscope which uses a CCD camera to replace the physical pinhole for materials science applications. Experimental scans were performed on a microscope resolution target, a semiconductor chip carrier, and a piece of etched silicon wafer. The data collected by the CCD were processed to yield images of the specimen. By selecting effective pixels in the recorded CCD images, a virtual pinhole is created. By analyzing the image moments of the imaging data, a lateral resolution enhancement is achieved by using a 20 × / NA = 0.4 microscope objective at 532 nm laser wavelength.

  8. Modular Scanning Confocal Microscope with Digital Image Processing

    PubMed Central

    McCluskey, Matthew D.

    2016-01-01

    In conventional confocal microscopy, a physical pinhole is placed at the image plane prior to the detector to limit the observation volume. In this work, we present a modular design of a scanning confocal microscope which uses a CCD camera to replace the physical pinhole for materials science applications. Experimental scans were performed on a microscope resolution target, a semiconductor chip carrier, and a piece of etched silicon wafer. The data collected by the CCD were processed to yield images of the specimen. By selecting effective pixels in the recorded CCD images, a virtual pinhole is created. By analyzing the image moments of the imaging data, a lateral resolution enhancement is achieved by using a 20 × / NA = 0.4 microscope objective at 532 nm laser wavelength. PMID:27829052

  9. Confocal microscopy of skin cancers: Translational advances toward clinical utility

    PubMed Central

    Rajadhyaksha, Milind

    2014-01-01

    Recent advances in translational research in and technology for confocal microscopy of skin cancers, toward clinical applications, are described. Advances in translational research are in diagnosis of melanoma in vivo, pre-operative mapping of lentigo maligna melanoma margins to guide surgery and intra-operative imaging of residual basal cell carcinomas to guide shave-biopsy. Advances in technology include mosaicing microscopy for detection of basal cell carcinomas in large areas of excised tissue, toward rapid pathology-at-the-bedside, and development of small, simple and low-cost line-scanning confocal microscopes for worldwide use in diverse primary healthcare settings. Current limitations and future opportunities and challenges for both clinicians and technologists are discussed. PMID:19964286

  10. Multiband enhanced absorption of monolayer graphene with attenuated total reflectance configuration and sensing application

    NASA Astrophysics Data System (ADS)

    Wang, Nan; Bu, Lingbing; Chen, Yunyun; Zheng, Gaige; Zou, Xiujuan; Xu, Linhua; Wang, Jicheng

    2017-01-01

    An enhanced absorption of monolayer graphene is obtained in a multilayer film-based attenuated total reflectance configuration in the visible wavelength range. The enhanced absorption under transverse magnetic and electric conditions is associated with the excitation of the waveguide mode in the thin-film layer, which is verified by the numerical calculation of field profiles. The obtained results manifest that the model induces a high field enhancement at the graphene-dielectric interface with the resonant angle, which implies potential sensing applications. The magnitude of the figure of merit is found to be three times higher than that of a conventional surface plasmon sensor.

  11. Application of the Empirical Mode Decomposition to Seismic Reflection and Ground Penetrating Radar Data

    NASA Astrophysics Data System (ADS)

    Battista, B. M.; Addison, A.; Knapp, C.; McGee, T.

    2006-12-01

    Advancements in signal processing may allow for improved imaging and analysis of complex geologic targets found in seismic reflection and ground penetrating radar data (GPR). A recent contribution to signal processing is the Empirical Mode Decomposition (EMD). The EMD empirically reduces a time series to several sub- signals whose sum yield the original time series. The benefit of such a process is to empirically develop signal-dependent, time-variant filters in the time domain. The objective of this work is to determine whether the EMD allows for empirically derived characteristics to be used in filter design and application, resulting in better filter performance and enhanced signal-to-noise ratio. Two data sets are used to show successful application of the EMD to geophysical data. Nonlinear cable strum is removed from one data set while the other is used to remove WOW noise from GPR data. Comparison to traditional techniques demonstrates the effectiveness of the technique.

  12. Re-scan confocal microscopy (RCM) improves the resolution of confocal microscopy and increases the sensitivity

    NASA Astrophysics Data System (ADS)

    De Luca, Giulia; Breedijk, Ronald; Hoebe, Ron; Stallinga, Sjoerd; Manders, Erik

    2017-03-01

    Re-scan confocal microscopy (RCM) is a new super-resolution technique based on a standard confocal microscope extended with a re-scan unit in the detection path that projects the emitted light onto a sensitive camera. In this paper the fundamental properties of RCM, lateral resolution, axial resolution and signal-to-noise ratio, are characterized and compared with properties of standard confocal microscopy. The results show that the lateral resolution of RCM is ~170 nm compared to ~240 nm of confocal microscopy for 488 nm excitation and 1.49 NA. As the theory predicts, this improved lateral resolution is independent of the pinhole diameter. In standard confocal microscopy, the same lateral resolution can only be achieved with an almost closed pinhole and, consequently, with a major loss of signal. We show that the sectioning capabilities of the standard confocal microscope are preserved in RCM and that the axial resolution of RCM is slightly better (~15%) than the standard confocal microscope. Furthermore, the signal-to-noise ratio in RCM is a factor of 2 higher than in standard confocal microscopy, also due to the use of highly sensitive modern cameras. In case the pinhole of a confocal microscope is adjusted in such way that the lateral resolution is comparable to that of RCM, the signal-to-noise ratio in RCM is 4 times higher than standard confocal microscopy. Therefore, RCM offers a good alternative to standard confocal microscopy for higher lateral resolution with the main advantage of strongly improved sensitivity.

  13. Multidepth imaging by chromatic dispersion confocal microscopy

    NASA Astrophysics Data System (ADS)

    Olsovsky, Cory A.; Shelton, Ryan L.; Saldua, Meagan A.; Carrasco-Zevallos, Oscar; Applegate, Brian E.; Maitland, Kristen C.

    2012-03-01

    Confocal microscopy has shown potential as an imaging technique to detect precancer. Imaging cellular features throughout the depth of epithelial tissue may provide useful information for diagnosis. However, the current in vivo axial scanning techniques for confocal microscopy are cumbersome, time-consuming, and restrictive when attempting to reconstruct volumetric images acquired in breathing patients. Chromatic dispersion confocal microscopy (CDCM) exploits severe longitudinal chromatic aberration in the system to axially disperse light from a broadband source and, ultimately, spectrally encode high resolution images along the depth of the object. Hyperchromat lenses are designed to have severe and linear longitudinal chromatic aberration, but have not yet been used in confocal microscopy. We use a hyperchromat lens in a stage scanning confocal microscope to demonstrate the capability to simultaneously capture information at multiple depths without mechanical scanning. A photonic crystal fiber pumped with a 830nm wavelength Ti:Sapphire laser was used as a supercontinuum source, and a spectrometer was used as the detector. The chromatic aberration and magnification in the system give a focal shift of 140μm after the objective lens and an axial resolution of 5.2-7.6μm over the wavelength range from 585nm to 830nm. A 400x400x140μm3 volume of pig cheek epithelium was imaged in a single X-Y scan. Nuclei can be seen at several depths within the epithelium. The capability of this technique to achieve simultaneous high resolution confocal imaging at multiple depths may reduce imaging time and motion artifacts and enable volumetric reconstruction of in vivo confocal images of the epithelium.

  14. Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

    PubMed

    Abd El-Maksoud, Rania H

    2016-02-20

    In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided.

  15. An addressable confocal microscope for functional imaging of neuronal activity

    NASA Astrophysics Data System (ADS)

    Bansal, Vivek

    2005-07-01

    The study of computation occurring in single neurons and small networks of interconnected neurons is often limited by (1) the number of sites that can be simultaneously probed with electrophysiology tools such as patch pipettes and (2) the recording speed of fluorescence imaging tools such as confocal or multiphoton microscopy. Even in the line scan mode of galvanometer-based scanners, where one scan dimension is sacrificed to gain overall speed, the effective frame rate is limited to less than 1 kHz with no flexibility in site selection. To overcome these limitations and allow the study of many sites throughout the dendritic arbor, we have developed an addressable confocal laser-scanning microscope that permits recording from user-selected sites-of-interest at high frame rates, in addition to conventional full frame imaging. Our system utilizes acousto-optic deflectors (AODs) in the illumination pathway to allow for rapid user-defined positioning of a focused laser spot. However, since AODs rely on diffraction to steer a laser beam, they cannot effectively descan the fluorescence emission spectrum as done in mirror-based systems which utilize reflection; this prevents the use of a stationary pinhole as a spatial filter. Instead, we implement an addressable spatial filter using a digital micromirror device (DMD) in conjunction with the AODs to achieve confocality. A registration algorithm synchronizes the AODs and DMD such that point illumination and point detection are always colocalized in conjugate image planes. The current version of the confocal system has a spatial resolution of ˜1 mum. Furthermore, by letting the user tailor which sites are visited, we have shown that recordings can be made at an aggregate frame rate of ˜40 kHz. We have successfully demonstrated that the system is capable of optical sectioning and thus exhibits the main advantage of a confocal microscope for light-scattering biological tissue. This property was used to create three

  16. Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics

    PubMed Central

    Hayashi, Shinichi; Okada, Yasushi

    2015-01-01

    Most current superresolution (SR) microscope techniques surpass the diffraction limit at the expense of temporal resolution, compromising their applications to live-cell imaging. Here we describe a new SR fluorescence microscope based on confocal microscope optics, which we name the spinning disk superresolution microscope (SDSRM). Theoretically, the SDSRM is equivalent to a structured illumination microscope (SIM) and achieves a spatial resolution of 120 nm, double that of the diffraction limit of wide-field fluorescence microscopy. However, the SDSRM is 10 times faster than a conventional SIM because SR signals are recovered by optical demodulation through the stripe pattern of the disk. Therefore a single SR image requires only a single averaged image through the rotating disk. On the basis of this theory, we modified a commercial spinning disk confocal microscope. The improved resolution around 120 nm was confirmed with biological samples. The rapid dynamics of micro­tubules, mitochondria, lysosomes, and endosomes were observed with temporal resolutions of 30–100 frames/s. Because our method requires only small optical modifications, it will enable an easy upgrade from an existing spinning disk confocal to a SR microscope for live-cell imaging. PMID:25717185

  17. Ultrafast superresolution fluorescence imaging with spinning disk confocal microscope optics.

    PubMed

    Hayashi, Shinichi; Okada, Yasushi

    2015-05-01

    Most current superresolution (SR) microscope techniques surpass the diffraction limit at the expense of temporal resolution, compromising their applications to live-cell imaging. Here we describe a new SR fluorescence microscope based on confocal microscope optics, which we name the spinning disk superresolution microscope (SDSRM). Theoretically, the SDSRM is equivalent to a structured illumination microscope (SIM) and achieves a spatial resolution of 120 nm, double that of the diffraction limit of wide-field fluorescence microscopy. However, the SDSRM is 10 times faster than a conventional SIM because SR signals are recovered by optical demodulation through the stripe pattern of the disk. Therefore a single SR image requires only a single averaged image through the rotating disk. On the basis of this theory, we modified a commercial spinning disk confocal microscope. The improved resolution around 120 nm was confirmed with biological samples. The rapid dynamics of micro-tubules, mitochondria, lysosomes, and endosomes were observed with temporal resolutions of 30-100 frames/s. Because our method requires only small optical modifications, it will enable an easy upgrade from an existing spinning disk confocal to a SR microscope for live-cell imaging.

  18. Confocal microlaparoscope for imaging the fallopian tube

    NASA Astrophysics Data System (ADS)

    Wu, Tzu-Yu; Rouse, Andrew R.; Chambers, Setsuko K.; Hatch, Kenneth D.; Gmitro, Arthur F.

    2014-11-01

    Recent evidence suggests that ovarian cancer can originate in the fallopian tube. Unlike many other cancers, poor access to the ovary and fallopian tubes has limited the ability to study the progression of this deadly disease and to diagnosis it during the early stage when it is most amenable to therapy. A rigid confocal microlaparoscope system designed to image the epithelial surface of the ovary in vivo was previously reported. A new confocal microlaparoscope with an articulating distal tip has been developed to enable in vivo access to human fallopian tubes. The new microlaparoscope is compatible with 5-mm trocars and includes a 2.2-mm-diameter articulating distal tip consisting of a bare fiber bundle and an automated dye delivery system for fluorescence confocal imaging. This small articulating device should enable the confocal microlaparoscope to image early stage ovarian cancer arising inside the fallopian tube. Ex vivo images of animal tissue and human fallopian tube using the new articulating device are presented along with in vivo imaging results using the rigid confocal microlaparoscope system.

  19. Multi-spectral confocal microendoscope for in-vivo imaging

    NASA Astrophysics Data System (ADS)

    Rouse, Andrew Robert

    The concept of in-vivo multi-spectral confocal microscopy is introduced. A slit-scanning multi-spectral confocal microendoscope (MCME) was built to demonstrate the technique. The MCME employs a flexible fiber-optic catheter coupled to a custom built slit-scan confocal microscope fitted with a custom built imaging spectrometer. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The design and performance of the miniature objective and focus assembly are discussed. The 3mm diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope. The confocal nature of the system provides optical sectioning with 3mum lateral resolution and 30mum axial resolution. The prism based multi-spectral detection assembly is typically configured to collect 30 spectral samples over the visible chromatic range. The spectral sampling rate varies from 4nm/pixel at 490nm to 8nm/pixel at 660nm and the minimum resolvable wavelength difference varies from 7nm to 18nm over the same spectral range. Each of these characteristics are primarily dictated by the dispersive power of the prism. The MCME is designed to examine cellular structures during optical biopsy and to exploit the diagnostic information contained within the spectral domain. The primary applications for the system include diagnosis of disease in the gastro-intestinal tract and female reproductive system. Recent data from the grayscale imaging mode are presented. Preliminary multi-spectral results from phantoms, cell cultures, and excised human tissue are presented to demonstrate the potential of in-vivo multi-spectral imaging.

  20. Application of scanning cytometry and confocal-microscopy-based image analysis for investigation the role of cytoskeletal elements during equine herpesvirus type 1 (EHV-1) infection of primary murine neurons.

    PubMed

    Słońska, A; Cymerys, J; Godlewski, M M; Bańbura, M W

    2016-11-01

    Equine herpesvirus type 1 (EHV-1), a member of Alphaherpesvirinae, has a broad host range in vitro, allowing for study of the mechanisms of productive viral infection, including intracellular transport in various cell cultures. In the current study, quantitative methods (scanning cytometry and real-time PCR) and confocal-microscopy-based image analysis were used to investigate the contribution of microtubules and neurofilaments in the transport of virus in primary murine neurons separately infected with two EHV-1 strains. Confocal-microscopy analysis revealed that viral antigen co-localized with the β-tubulin fibres within the neurites of infected cells. Alterations in β-tubulin and neurofilaments were evaluated by confocal microscopy and scanning cytometry. Real-time PCR analysis demonstrated that inhibitor-induced (nocodazole, EHNA) disruption of microtubules and dynein significantly reduced EHV-1 replication in neurons. Our results suggest that microtubules together with the motor protein - dynein, are involved in EHV-1 replication process in neurons. Moreover, the data presented here and our earlier results support the hypothesis that microtubules and actin filaments play an important role in the EHV-1 transport in primary murine neurons, and that both cytoskeletal structures complement each-other.

  1. 3D Image Analysis of Geomaterials using Confocal Microscopy

    NASA Astrophysics Data System (ADS)

    Mulukutla, G.; Proussevitch, A.; Sahagian, D.

    2009-05-01

    Confocal microscopy is one of the most significant advances in optical microscopy of the last century. It is widely used in biological sciences but its application to geomaterials lingers due to a number of technical problems. Potentially the technique can perform non-invasive testing on a laser illuminated sample that fluoresces using a unique optical sectioning capability that rejects out-of-focus light reaching the confocal aperture. Fluorescence in geomaterials is commonly induced using epoxy doped with a fluorochrome that is impregnated into the sample to enable discrimination of various features such as void space or material boundaries. However, for many geomaterials, this method cannot be used because they do not naturally fluoresce and because epoxy cannot be impregnated into inaccessible parts of the sample due to lack of permeability. As a result, the confocal images of most geomaterials that have not been pre-processed with extensive sample preparation techniques are of poor quality and lack the necessary image and edge contrast necessary to apply any commonly used segmentation techniques to conduct any quantitative study of its features such as vesicularity, internal structure, etc. In our present work, we are developing a methodology to conduct a quantitative 3D analysis of images of geomaterials collected using a confocal microscope with minimal amount of prior sample preparation and no addition of fluorescence. Two sample geomaterials, a volcanic melt sample and a crystal chip containing fluid inclusions are used to assess the feasibility of the method. A step-by-step process of image analysis includes application of image filtration to enhance the edges or material interfaces and is based on two segmentation techniques: geodesic active contours and region competition. Both techniques have been applied extensively to the analysis of medical MRI images to segment anatomical structures. Preliminary analysis suggests that there is distortion in the

  2. Confocal multiview light-sheet microscopy

    PubMed Central

    Medeiros, Gustavo de; Norlin, Nils; Gunther, Stefan; Albert, Marvin; Panavaite, Laura; Fiuza, Ulla-Maj; Peri, Francesca; Hiiragi, Takashi; Krzic, Uros; Hufnagel, Lars

    2015-01-01

    Selective-plane illumination microscopy has proven to be a powerful imaging technique due to its unsurpassed acquisition speed and gentle optical sectioning. However, even in the case of multiview imaging techniques that illuminate and image the sample from multiple directions, light scattering inside tissues often severely impairs image contrast. Here we combine multiview light-sheet imaging with electronic confocal slit detection implemented on modern camera sensors. In addition to improved imaging quality, the electronic confocal slit detection doubles the acquisition speed in multiview setups with two opposing illumination directions allowing simultaneous dual-sided illumination. Confocal multiview light-sheet microscopy eliminates the need for specimen-specific data fusion algorithms, streamlines image post-processing, easing data handling and storage. PMID:26602977

  3. Performance of "Moth Eye" Anti-Reflective Coatings for Solar Cell Applications

    SciTech Connect

    Clark, E.; Kane, M.; Jiang, P.

    2011-03-14

    An inexpensive, effective anti-reflective coating (ARC) has been developed at the University of Florida to significantly enhance the absorption of light by silicon in solar cells. This coating has nano-scale features, and its microstructure mimics that of various night active insects (e.g. a moth's eye). It is a square array of pillars, each about 700 nm high and having a diameter of about 300 nm. Samples of silicon having this coating were exposed either to various combinations of either elevated temperature and humidity or to gamma irradiation ({sup 60}Co) at the Savannah River National Laboratory, or to a broad spectrum ultraviolet light and to a 532 nm laser light at the University of Florida. The anti-reflective properties of the coatings were unaffected by any of these environmental stresses, and the microstructure of the coating was also unaffected. In fact, the reflectivity of the gamma irradiated ARC became lower (advantageous for solar cell applications) at wavelengths between 400 and 1000 nm. These results show that this coating is robust and should be tested in actual systems exposed to either weather or a space environment. Structural details of the ARCs were studied to optimize their performance. Square arrays performed better than hexagonal arrays - the natural moth-eye coating is indeed a square array. The optimal depth of the templated nanopillars in the ARC was investigated. A wet etching technology for ARC formation was developed that would be less expensive and much faster than dry etching. Theoretical modeling revealed that dimple arrays should perform better than nipple arrays. A method of fabricating both dimple and nipple arrays having the same length was developed, and the dimple arrays performed better than the nipple arrays, in agreement with the modeling. The commercial viability of the technology is quite feasible, since the technology is scalable and inexpensive. This technology is also compatible with current industrial fabrication of

  4. Multiple-reflection time-of-flight mass spectrometry for in situ applications

    NASA Astrophysics Data System (ADS)

    Dickel, T.; Plaß, W. R.; Lang, J.; Ebert, J.; Geissel, H.; Haettner, E.; Jesch, C.; Lippert, W.; Petrick, M.; Scheidenberger, C.; Yavor, M. I.

    2013-12-01

    Multiple-reflection time-of-flight mass spectrometers (MR-TOF-MS) have recently been installed at different low-energy radioactive ion beam facilities. They are used as isobar separators with high ion capacity and as mass spectrometers with high mass resolving power and accuracy for short-lived nuclei. Furthermore, MR-TOF-MS have a huge potential for applications in other fields, such as chemistry, biology, medicine, space science, and homeland security. The development, commissioning and results of an MR-TOF-MS is presented, which serves as proof-of-principle to show that very high mass resolving powers (∼105) can be achieved in a compact device (length ∼30 cm). Based on this work, an MR-TOF-MS for in situ application has been designed. For the first time, this device combines very high mass resolving power (>105), mobility, and an atmospheric pressure inlet in one instrument. It will enable in situ measurements without sample preparation at very high mass accuracy. Envisaged applications of this mobile MR-TOF-MS are discussed.

  5. Cross-Disciplinary Exploration and Application of Reflection as a High Impact Pedagogy

    ERIC Educational Resources Information Center

    Summers, Sarah E.; Chenette, Heather C. S.; Ingram, Ella L.; McCormack, Jay P.; Cunningham, Patrick J.

    2016-01-01

    Reflection is a high-impact practice in education. This paper explores the premise, approach, and outcomes of a learning community centered on scholarly engagement with the literature of reflection. Using the reflection model operationalized by a national consortium, we developed, implemented, and assessed reflection activities designed to create…

  6. Acid-degradable hyperbranched polymer and its application in bottom anti-reflective coatings

    NASA Astrophysics Data System (ADS)

    Mercado, Ramil-Marcelo L.; Xu, Hao; Lowes, Joyce A.; Meador, Jim D.; Guerrero, Douglas J.

    2008-11-01

    A photosensitive developer-soluble bottom anti-reflective coating (DBARC) system is described for KrF and ArF lithographic applications. The system contains an acid-degradable branched polymer that is self-crosslinked into a polymeric film after spin coating and baking at high temperature, rendering a solvent-insoluble coating. The DBARC coating is tunable in terms having the appropriate light absorption (k value) and thickness for desirable reflection control. After the exposure of the resist, the DBARC layer decrosslinks into developer-soluble small molecules in the presence of photoacid generator (PAG). Thus the DBARC layer is removed simultaneously with the photoresist in the development process, instead of being etched away in a plasma-etching chamber in the case of traditional BARC layers. The etch budget is significantly improved so that a thin resist can be used for better resolution. Alternatively, the etch step can be omitted in the case of the formation of layers that may be damaged by exposure to plasma.

  7. Application of Neutron Reflectivity for Studies of Biomolecular Structures and Functions at Interfaces

    SciTech Connect

    Johs, Alexander; Liang, Liyuan; Gu, Baohua; Ankner, John Francis; Wang, Wei

    2009-01-01

    Structures and functions of cell membranes are of central importance in understanding processes such as cell signaling, chemotaxis, redox transformation, biofilm formation, and mineralization occurring at interfaces. This chapter provides an overview of the application of neutron reflectivity (NR) as a unique tool for probing biomolecular structures and mechanisms as a first step toward understanding protein protein, protein lipid, and protein mineral interactions at the membrane substrate interfaces. Emphasis is given to the review of existing literature on the assembly of biomimetic membrane systems, such as supported membranes for NR studies, and demonstration of model calculations showing the potential of NR to elucidate molecular fundamentals of microbial cell mineral interactions and structure functional relationships of electron transport pathways. The increased neutron flux afforded by current and upcoming neutron sources holds promise for elucidating detailed processes such as phase separation, formation of microdomains, and membrane interactions with proteins and peptides in biological systems.

  8. Total-Internal-Reflection Platforms for Chemical and Biological Sensing Applications

    NASA Astrophysics Data System (ADS)

    Sapsford, Kim E.

    Sensing platforms based on the principle of total internal reflection (TIR) represent a fairly mature yet still expanding and exciting field of research. Sensor development has mainly been driven by the need for rapid, stand-alone, automated devices for application in the fields of clinical diagnosis and screening, food and water safety, environmental monitoring, and chemical and biological warfare agent detection. The technologies highlighted in this chapter are continually evolving, taking advantage of emerging advances in microfabrication, lab-on-a-chip, excitation, and detection techniques. This chapter describes many of the underlying principles of TIR-based sensing platforms and additionally focusses on planar TIR fluorescence (TIRF)-based chemical and biological sensors.

  9. Infrared Reflection-Absorption Spectroscopy: Principles and Applications to Lipid-Protein Interaction in Langmuir Films

    PubMed Central

    Mendelsohn, Richard; Mao, Guangru; Flach, Carol R.

    2010-01-01

    Infrared reflection-absorption spectroscopy (IRRAS) of lipid/protein monolayer films in situ at the air/water interface provides unique molecular structure and orientation information from the film constituents. The technique is thus well suited for studies of lipid/protein interaction in a physiologically relevant environment. Initially, the nature of the IRRAS experiment is described and the molecular structure information that may be obtained is recapitulated. Subsequently, several types of applications, including the determination of lipid chain conformation and tilt as well as elucidation of protein secondary structure are reviewed. The current article attempts to provide the reader with an understanding of the current capabilities of IRRAS instrumentation and the type of results that have been achieved to date from IRRAS studies of lipids, proteins and lipid/protein films of progressively increasing complexity. Finally, possible extensions of the technology are briefly considered. PMID:20004639

  10. Confocal acoustic radiation force optical coherence elastography using a ring ultrasonic transducer

    SciTech Connect

    Qi, Wenjuan; Li, Rui; Ma, Teng; Kirk Shung, K.; Zhou, Qifa; Chen, Zhongping

    2014-03-24

    We designed and developed a confocal acoustic radiation force optical coherence elastography system. A ring ultrasound transducer was used to achieve reflection mode excitation and generate an oscillating acoustic radiation force in order to generate displacements within the tissue, which were detected using the phase-resolved optical coherence elastography method. Both phantom and human tissue tests indicate that this system is able to sense the stiffness difference of samples and quantitatively map the elastic property of materials. Our confocal setup promises a great potential for point by point elastic imaging in vivo and differentiation of diseased tissues from normal tissue.

  11. Three-dimensional measurement and visualization of internal flow of a moving droplet using confocal micro-PIV.

    PubMed

    Kinoshita, Haruyuki; Kaneda, Shohei; Fujii, Teruo; Oshima, Marie

    2007-03-01

    This paper presents a micro-flow diagnostic technique, 'high-speed confocal micro-particle image velocimetry (PIV)', and its application to the internal flow measurement of a droplet passing through a microchannel. A confocal micro-PIV system has been successfully constructed wherein a high-speed confocal scanner is combined with the conventional micro-PIV technique. The confocal micro-PIV system enables us to obtain a sequence of sharp and high-contrast cross-sectional particle images at 2000 frames s(-1). This study investigates the confocal depth, which is a significant parameter to determine the out-of-plane measurement resolution in confocal micro-PIV. Using the present confocal micro-PIV system, we can measure velocity distributions of micro-flows in a 228 microm x 171 microm region with a confocal depth of 1.88 microm. We also propose a three-dimensional velocity measurement method based on the confocal micro-PIV and the equation of continuity. This method enables us to measure three velocity components in a three-dimensional domain of micro flows. The confocal micro-PIV system is applied to the internal flow measurement of a droplet. We have measured three-dimensional distributions of three-component velocities of a droplet traveling in a 100 microm (width) x 58 microm (depth) channel. A volumetric velocity distribution inside a droplet is obtained by the confocal micro-PIV and the three-dimensional flow structure inside the droplet is investigated. The measurement results suggest that a three-dimensional and complex circulating flow is formed inside the droplet.

  12. Three-dimensional confocal optical imagery of precambrian microscopic organisms.

    PubMed

    Schopf, J William; Tripathi, Abhishek B; Kudryavtsev, Anatoliy B

    2006-02-01

    A major difficulty that has long hindered studies of organic-walled Precambrian microbes in petrographic thin sections is the accurate documentation of their three-dimensional morphology. To address this need, we here demonstrate the use of confocal laser scanning microscopy. This technique, both non-intrusive and non-destructive, can provide data by which to objectively characterize, in situ and at submicron-scale resolution, the cellular and organismal morphology of permineralized (petrified) microorganisms. Application of this technique can provide information in three dimensions about the morphology, taphonomy, and fidelity of preservation of such fossils at a spatial resolution unavailable by any other means.

  13. Synthetic-aperture chirp confocal imaging.

    PubMed

    Chien, Wei-Chen; Dilworth, D S; Liu, Elson; Leith, E N

    2006-01-20

    An imaging system that combines synthetic-aperture imaging, holography, and an optical chirp with confocal imaging is described and analyzed. Comparisons are made with synthetic-aperture radar systems. Adaptation of several synthetic-aperture radar techniques to the optical counterparts is suggested.

  14. Active confocal imaging for visual prostheses.

    PubMed

    Jung, Jae-Hyun; Aloni, Doron; Yitzhaky, Yitzhak; Peli, Eli

    2015-06-01

    There are encouraging advances in prosthetic vision for the blind, including retinal and cortical implants, and other "sensory substitution devices" that use tactile or electrical stimulation. However, they all have low resolution, limited visual field, and can display only few gray levels (limited dynamic range), severely restricting their utility. To overcome these limitations, image processing or the imaging system could emphasize objects of interest and suppress the background clutter. We propose an active confocal imaging system based on light-field technology that will enable a blind user of any visual prosthesis to efficiently scan, focus on, and "see" only an object of interest while suppressing interference from background clutter. The system captures three-dimensional scene information using a light-field sensor and displays only an in-focused plane with objects in it. After capturing a confocal image, a de-cluttering process removes the clutter based on blur difference. In preliminary experiments we verified the positive impact of confocal-based background clutter removal on recognition of objects in low resolution and limited dynamic range simulated phosphene images. Using a custom-made multiple-camera system based on light-field imaging, we confirmed that the concept of a confocal de-cluttered image can be realized effectively.

  15. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    EPA Science Inventory

    Laser power abstract
    The reliability of the confocal laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one ...

  16. Quantitative phase-contrast confocal microscope

    PubMed Central

    Liu, Changgeng; Marchesini, Stefano; Kim, Myung K.

    2014-01-01

    We present a quantitative phase-contrast confocal microscope (QPCCM) by combining a line-scanning confocal system with digital holography (DH). This combination can merge the merits of these two different imaging modalities. High-contrast intensity images with low coherent noise, and the optical sectioning capability are made available due to the confocality. Phase profiles of the samples become accessible thanks to DH. QPCCM is able to quantitatively measure the phase variations of optical sections of the opaque samples and has the potential to take high-quality intensity and phase images of non-opaque samples such as many biological samples. Because each line scan is recorded by a hologram that may contain the optical aberrations of the system, it opens avenues for a variety of numerical aberration compensation methods and development of full digital adaptive optics confocal system to emulate current hardware-based adaptive optics system for biomedical imaging, especially ophthalmic imaging. Preliminary experiments with a microscope objective of NA 0.65 and 40 × on opaque samples are presented to demonstrate this idea. The measured lateral and axial resolutions of the intensity images from the current system are ~0.64μm and ~2.70μm respectively. The noise level of the phase profile by QPCCM is ~2.4nm which is better than the result by DH. PMID:25089404

  17. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: AXIAL RESOLUTION

    EPA Science Inventory

    Abstract

    Confocal Microscopy System Performance: Axial resolution.
    Robert M. Zucker, PhD

    Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Re...

  18. Confocal microscopy imaging of solid tissue

    EPA Science Inventory

    Confocal laser scanning microscopy (CLSM) is a technique that is capable of generating serial sections of whole-mount tissue and then reassembling the computer acquired images as a virtual 3-dimensional structure. In many ways CLSM offers an alternative to traditional sectioning ...

  19. Active confocal imaging for visual prostheses

    PubMed Central

    Jung, Jae-Hyun; Aloni, Doron; Yitzhaky, Yitzhak; Peli, Eli

    2014-01-01

    There are encouraging advances in prosthetic vision for the blind, including retinal and cortical implants, and other “sensory substitution devices” that use tactile or electrical stimulation. However, they all have low resolution, limited visual field, and can display only few gray levels (limited dynamic range), severely restricting their utility. To overcome these limitations, image processing or the imaging system could emphasize objects of interest and suppress the background clutter. We propose an active confocal imaging system based on light-field technology that will enable a blind user of any visual prosthesis to efficiently scan, focus on, and “see” only an object of interest while suppressing interference from background clutter. The system captures three-dimensional scene information using a light-field sensor and displays only an in-focused plane with objects in it. After capturing a confocal image, a de-cluttering process removes the clutter based on blur difference. In preliminary experiments we verified the positive impact of confocal-based background clutter removal on recognition of objects in low resolution and limited dynamic range simulated phosphene images. Using a custom-made multiple-camera system, we confirmed that the concept of a confocal de-cluttered image can be realized effectively using light field imaging. PMID:25448710

  20. Vibrometry using a chromatic confocal sensor

    NASA Astrophysics Data System (ADS)

    Berkovic, G.; Zilberman, S.; Shafir, E.; Cohen-Sabban, J.

    2014-05-01

    We demonstrate vibrometry using a chromatic confocal sensor which measures displacements with 0.1 μm resolution at a rate of 10 kHz. This technique was used to study the vibration of a musical tuning fork with a resonance at 523 Hz. Other examples presented include vibration of water waves and multiple point vibrometry of a vibrating steel rod.

  1. Confocal microscopy of Aspergillus fumigatus keratitis

    PubMed Central

    Avunduk, A M; Beuerman, R W; Varnell, E D; Kaufman, H E

    2003-01-01

    Aim: To use a confocal microscope to characterise the treated and untreated courses of fungal keratitis. Methods: In the first experiment, Aspergillus fumigatus stromal keratitis was produced in both eyes of seven New Zealand white rabbits. In the second experiment, keratitis was induced in right eyes of 20 rabbits. Group 1 rabbits were treated with topical fluconazole, group 2 rabbits received oral fluconazole, and group 3 rabbits were used as controls. The rabbits were examined with a slit lamp and confocal microscope 2, 6, 10, 14, and 20 days after inoculation. The corneal cultures were taken on days 2, 14, and 20 and biopsies were taken on days 2 and 22. Results: On days 14 and 22 confocal microscopy was more sensitive than culture technique in both treated and untreated animals, since not all cases of fungal keratitis can be cultured. Conclusion: This study indicates that confocal microscopy is a rapid and sensitive diagnostic tool for both the early diagnosis and non-invasive follow up of fungal keratitis PMID:12642300

  2. Extending Whole Slide Imaging: Color Darkfield Internal Reflection Illumination (DIRI) for Biological Applications

    PubMed Central

    Namiki, Kana; Miyawaki, Atsushi; Ishikawa, Takuji

    2017-01-01

    Whole slide imaging (WSI) is a useful tool for multi-modal imaging, and in our work, we have often combined WSI with darkfield microscopy. However, traditional darkfield microscopy cannot use a single condenser to support high- and low-numerical-aperture objectives, which limits the modality of WSI. To overcome this limitation, we previously developed a darkfield internal reflection illumination (DIRI) microscope using white light-emitting diodes (LEDs). Although the developed DIRI is useful for biological applications, substantial problems remain to be resolved. In this study, we propose a novel illumination technique called color DIRI. The use of three-color LEDs dramatically improves the capability of the system, such that color DIRI (1) enables optimization of the illumination color; (2) can be combined with an oil objective lens; (3) can produce fluorescence excitation illumination; (4) can adjust the wavelength of light to avoid cell damage or reactions; and (5) can be used as a photostimulator. These results clearly illustrate that the proposed color DIRI can significantly extend WSI modalities for biological applications. PMID:28085892

  3. Extending Whole Slide Imaging: Color Darkfield Internal Reflection Illumination (DIRI) for Biological Applications.

    PubMed

    Kawano, Yoshihiro; Namiki, Kana; Miyawaki, Atsushi; Ishikawa, Takuji

    2017-01-01

    Whole slide imaging (WSI) is a useful tool for multi-modal imaging, and in our work, we have often combined WSI with darkfield microscopy. However, traditional darkfield microscopy cannot use a single condenser to support high- and low-numerical-aperture objectives, which limits the modality of WSI. To overcome this limitation, we previously developed a darkfield internal reflection illumination (DIRI) microscope using white light-emitting diodes (LEDs). Although the developed DIRI is useful for biological applications, substantial problems remain to be resolved. In this study, we propose a novel illumination technique called color DIRI. The use of three-color LEDs dramatically improves the capability of the system, such that color DIRI (1) enables optimization of the illumination color; (2) can be combined with an oil objective lens; (3) can produce fluorescence excitation illumination; (4) can adjust the wavelength of light to avoid cell damage or reactions; and (5) can be used as a photostimulator. These results clearly illustrate that the proposed color DIRI can significantly extend WSI modalities for biological applications.

  4. Experimental design for reflection measurements of highly reactive liquid or solid substances with application to liquid sodium

    SciTech Connect

    Chan, S.H.; Gossler, A.A.

    1980-06-30

    A versatile goniometer system with associated electronic components and mechanical instruments has been assembled. It is designed to measure spectral, specular reflectances of highly reactive liquid or solid substances over a spectral range of 0.3 to 9 ..mu.. and incidence angles of 12 to 30/sup 0/ off the normal direction. The capability of measuring reflectances of liquid substances clearly distinguishes this experimental design from conventional systems which are applicable only to solid substances. This design has been used to measure the spectral, specular reflectance of liquid sodium and preliminary results obtained are compared with those of solid sodium measured by other investigators.

  5. Measurement of steep edges and undercuts in confocal microscopy.

    PubMed

    Mueller, T; Jordan, M; Schneider, T; Poesch, A; Reithmeier, E

    2016-05-01

    Confocal microscopy is widely used to measure the surface topography of specimen with a precision in the micrometer range. The measurement uncertainty and quality of the acquired data of confocal microscopy depends on various effects, such as optical aberrations, vibrations of the measurement setup and variations in the surface reflectivity. In this article, the influence of steep edges and undercuts on measurement results is examined. Steep edges on the specimen's surface lead to a reduced detector signal which influences the measurement accuracy and undercuts cause surface regions, which cannot be captured in a measurement. The article describes a method to overcome the negative effects of steep edges and undercuts by capturing several measurements of the surface with different angles between the surface and the optical axis of the objective. An algorithm is introduced which stitches different angle measurements together without knowledge of the exact position and orientation of the rotation axis. Thus, the measurement uncertainty due to steep edges and undercuts can be avoided without expensive high-precision rotation stages and time consuming adjustment of the measurement setup.

  6. Cosmetic assessment of the human hair by confocal microscopy.

    PubMed

    Hadjur, Christophe; Daty, Gérard; Madry, Geneviève; Corcuff, Pierre

    2002-01-01

    The optical sectioning property of the confocal microscope offers a breakthrough from the classic observation of the hair in a scanning electron microscope (SEM). Confocal microscopy requires minimal sampling preparation, and the hair can be observed in its natural environment with less damage than by other microscopic methods such as SEM. While used in the reflection mode, the true morphology of the cuticle and the various exogenous deposits at the surface can be identified and quantified. This relatively noninvasive, nondestructive technique is routinely used by us to monitor the efficiency of cleansing shampoos, to assess the homogeneity of layering polymers, and to evaluate the changes they induce in the optical properties of the hair surface in terms of opacity, transparency, and brilliancy. A second important field of investigation uses the fluorescence channel which reveals the internal structure of the hair. Fluorescent probes (rhodamine and its derivatives) demonstrate the routes of penetration and outline the geometry of cortical cells and of the medulla according to their lipophilic or hydrophilic properties. A volume rendering of a hair cylinder provides a better understanding of the interrelationships between cuticle cells, cortical cells, and the medullar channel. This recent technology is becoming an invaluable tool for the cosmetic assessment of the hair.

  7. Imaging intracellular protein dynamics by spinning disk confocal microscopy

    PubMed Central

    Stehbens, Samantha; Pemble, Hayley; Murrow, Lindsay; Wittmann, Torsten

    2012-01-01

    The palette of fluorescent proteins has grown exponentially over the last decade, and as a result live imaging of cells expressing fluorescently tagged proteins is becoming more and more main stream. Spinning disk confocal microscopy (SDC) is a high speed optical sectioning technique, and a method of choice to observe and analyze intracellular fluorescent protein dynamics at high spatial and temporal resolution. In an SDC system, a rapidly rotating pinhole disk generates thousands of points of light that scan the specimen simultaneously, which allows direct capture of the confocal image with low noise scientific grade cooled charged-coupled device (CCD) cameras, and can achieve frame rates of up 1000 frames per second. In this chapter we describe important components of a state-of-the-art spinning disk system optimized for live cell microscopy, and provide a rationale for specific design choices. We also give guidelines how other imaging techniques such as total internal reflection (TIRF) microscopy or spatially controlled photoactivation can be coupled with SDC imaging, and provide a short protocol on how to generate cell lines stably expressing fluorescently tagged proteins by lentivirus-mediated transduction. PMID:22264541

  8. Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials.

    PubMed

    Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

    2014-08-14

    This work studies the applicability of a Diffuse Reflectance Infrared Fourier Transform handheld device to perform in situ analyses on Cultural Heritage assets. This portable diffuse reflectance spectrometer has been used to characterise and diagnose the conservation state of (a) building materials of the Guevara Palace (15th century, Segura, Basque Country, Spain) and (b) different 19th century wallpapers manufactured by the Santa Isabel factory (Vitoria-Gasteiz, Basque Country, Spain) and by the well known Dufour and Leroy manufacturers (Paris, France), all of them belonging to the Torre de los Varona Castle (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection.

  9. Applicability of a Diffuse Reflectance Infrared Fourier Transform handheld spectrometer to perform in situ analyses on Cultural Heritage materials

    NASA Astrophysics Data System (ADS)

    Arrizabalaga, Iker; Gómez-Laserna, Olivia; Aramendia, Julene; Arana, Gorka; Madariaga, Juan Manuel

    2014-08-01

    This work studies the applicability of a Diffuse Reflectance Infrared Fourier Transform handheld device to perform in situ analyses on Cultural Heritage assets. This portable diffuse reflectance spectrometer has been used to characterise and diagnose the conservation state of (a) building materials of the Guevara Palace (15th century, Segura, Basque Country, Spain) and (b) different 19th century wallpapers manufactured by the Santa Isabel factory (Vitoria-Gasteiz, Basque Country, Spain) and by the well known Dufour and Leroy manufacturers (Paris, France), all of them belonging to the Torre de los Varona Castle (Villanañe, Basque Country, Spain). In all cases, in situ measurements were carried out and also a few samples were collected and measured in the laboratory by diffuse reflectance spectroscopy (DRIFT) in order to validate the information obtained by the handheld instrument. In the analyses performed in situ, distortions in the diffuse reflectance spectra can be observed due to the presence of specular reflection, showing the inverted bands caused by the Reststrahlen effect, in particular on those IR bands with the highest absorption coefficients. This paper concludes that the results obtained in situ by a diffuse reflectance handheld device are comparable to those obtained with laboratory diffuse reflectance spectroscopy equipment and proposes a few guidelines to acquire good spectra in the field, minimising the influence caused by the specular reflection.

  10. Two-photon confocal microscopy in the study of the volume characteristics of semiconductors

    NASA Astrophysics Data System (ADS)

    Kalinushkin, V. P.; Uvarov, O. V.

    2016-12-01

    Zn-Se crystals are used to analyze prospects for application of two-photon confocal microscopy in the study of plane and volume interband and impurity luminescence in semiconductors. Such maps can be formed with a depth step and planar spatial resolution of several micrometers at distances of up to 1 mm from the surface. The method is used to detect luminescence-active inhomogeneities in crystals and study their structure and luminescence characteristics. Prospects for the application of the two-photon confocal microscopy in the study of direct-band-semiconductors and materials of the fourth group are discussed.

  11. Laser confocal microscope with wavelet-profiled point spread function

    NASA Astrophysics Data System (ADS)

    Romero, Mary Jacquiline; Bautista, Godofredo; Daria, Vincent Ricardo; Saloma, Caesar

    2010-04-01

    We report a laser-scanning confocal reflectance microscope with a wavelet-profiled point spread function (PSF) for rapid multi-resolution extraction and analysis of microscopic object features. The PSF is generated via holography by encoding a π-phase shifting disk unto a collimated laser beam via a phase-only spatial light modulator (SLM) that is positioned at the pupil plane of the focusing objective lens. Scaling of the transverse PSF distribution is achieved by selecting a suitable ratio of the π-phase shifting disk radius and the pupil aperture radius. With one and the same objective lens and one SLM to control the phase profile of the pupil function, we produce amplitude PSF distributions that are accurate scaled representations of the circularly-symmetric Mexican hat mother wavelet.

  12. Capillary array electrophoresis with confocal fluorescence rotary scanner.

    PubMed

    Wang, Jun; Sun, Guangming; Bai, Jiling; Wang, Li

    2003-12-01

    A capillary array electrophoresis system with a rotary confocal fluorescence scanner is reported. A high speed direct current rotary motor, combined with a rotary encoder and a reflection mirror, has been designed to direct the excitation laser beam precisely to a round array of capillaries which are symmetrically distributed around the motor. The rotary encoder is introduced to accurately orientate the position of each capillary and its output signal triggers the data acquisition system to record the fluorescence signal corresponding to each capillary. Separation of enantiomers of glutamic acid, methionine and tryptophan with different additives are demonstrated by this system. The experimental results indicate that this setup can be used to optimize separation methods for capillary electrophoresis as quickly as possible.

  13. Surface microstructure profilometry based on laser confocal feedback

    NASA Astrophysics Data System (ADS)

    Wang, Weiping; Zhang, Shulian; Li, Yan

    2015-10-01

    We demonstrate a surface microstructure profile measurement method, which utilizes the positioning ability of confocal technology and the high sensitivity of frequency-shift feedback of a microchip laser. The surface profile is measured by combination of the amplitude and phase information of the feedback light reflected by the sample. The amplitude information is used for coarse measurement and to determine the integral number of half lasing wavelengths contained in the sample profile variation. The phase information is used for fine measurement and to determine the fractional number. The measurement realizes both a large axial measuring range of tens of microns and a high axial resolution of ˜2 nm. Meanwhile, a heterodyne phase measurement approach is introduced to compensate for environmental disturbance and to realize high axial resolution measurement under common room conditions. The surface profile of a grating is measured and proves the feasibility of the method.

  14. Endoscopic probe optics for spectrally encoded confocal microscopy.

    PubMed

    Kang, Dongkyun; Carruth, Robert W; Kim, Minkyu; Schlachter, Simon C; Shishkov, Milen; Woods, Kevin; Tabatabaei, Nima; Wu, Tao; Tearney, Guillermo J

    2013-01-01

    Spectrally encoded confocal microscopy (SECM) is a form of reflectance confocal microscopy that can achieve high imaging speeds using relatively simple probe optics. Previously, the feasibility of conducting large-area SECM imaging of the esophagus in bench top setups has been demonstrated. Challenges remain, however, in translating SECM into a clinically-useable device; the tissue imaging performance should be improved, and the probe size needs to be significantly reduced so that it can fit into luminal organs of interest. In this paper, we report the development of new SECM endoscopic probe optics that addresses these challenges. A custom water-immersion aspheric singlet (NA = 0.5) was developed and used as the objective lens. The water-immersion condition was used to reduce the spherical aberrations and specular reflection from the tissue surface, which enables cellular imaging of the tissue deep below the surface. A custom collimation lens and a small-size grating were used along with the custom aspheric singlet to reduce the probe size. A dual-clad fiber was used to provide both the single- and multi- mode detection modes. The SECM probe optics was made to be 5.85 mm in diameter and 30 mm in length, which is small enough for safe and comfortable endoscopic imaging of the gastrointestinal tract. The lateral resolution was 1.8 and 2.3 µm for the single- and multi- mode detection modes, respectively, and the axial resolution 11 and 17 µm. SECM images of the swine esophageal tissue demonstrated the capability of this device to enable the visualization of characteristic cellular structural features, including basal cell nuclei and papillae, down to the imaging depth of 260 µm. These results suggest that the new SECM endoscopic probe optics will be useful for imaging large areas of the esophagus at the cellular scale in vivo.

  15. Endoscopic probe optics for spectrally encoded confocal microscopy

    PubMed Central

    Kang, DongKyun; Carruth, Robert W.; Kim, Minkyu; Schlachter, Simon C.; Shishkov, Milen; Woods, Kevin; Tabatabaei, Nima; Wu, Tao; Tearney, Guillermo J.

    2013-01-01

    Spectrally encoded confocal microscopy (SECM) is a form of reflectance confocal microscopy that can achieve high imaging speeds using relatively simple probe optics. Previously, the feasibility of conducting large-area SECM imaging of the esophagus in bench top setups has been demonstrated. Challenges remain, however, in translating SECM into a clinically-useable device; the tissue imaging performance should be improved, and the probe size needs to be significantly reduced so that it can fit into luminal organs of interest. In this paper, we report the development of new SECM endoscopic probe optics that addresses these challenges. A custom water-immersion aspheric singlet (NA = 0.5) was developed and used as the objective lens. The water-immersion condition was used to reduce the spherical aberrations and specular reflection from the tissue surface, which enables cellular imaging of the tissue deep below the surface. A custom collimation lens and a small-size grating were used along with the custom aspheric singlet to reduce the probe size. A dual-clad fiber was used to provide both the single- and multi- mode detection modes. The SECM probe optics was made to be 5.85 mm in diameter and 30 mm in length, which is small enough for safe and comfortable endoscopic imaging of the gastrointestinal tract. The lateral resolution was 1.8 and 2.3 µm for the single- and multi- mode detection modes, respectively, and the axial resolution 11 and 17 µm. SECM images of the swine esophageal tissue demonstrated the capability of this device to enable the visualization of characteristic cellular structural features, including basal cell nuclei and papillae, down to the imaging depth of 260 µm. These results suggest that the new SECM endoscopic probe optics will be useful for imaging large areas of the esophagus at the cellular scale in vivo. PMID:24156054

  16. Assessing the tissue-imaging performance of confocal microscope architectures via Monte Carlo simulations.

    PubMed

    Chen, Ye; Wang, Danni; Liu, Jonathan T C

    2012-11-01

    Various confocal microscope architectures have been developed for in vivo tissue imaging, including single-axis confocal (SAC) and dual-axis confocal (DAC) configurations utilizing both point-scanning (PS) and line-scanning (LS) approaches. While it is known that these design variations lead to tradeoffs in imaging performance, a quantitative comparison of the imaging performance of these configurations in highly turbid media would be of value. Here, we perform Monte Carlo simulations to evaluate the optical-sectioning capability of these various confocal microscope architectures in reflectance mode. In particular, we investigate the axial and transverse responses of these configurations to reflective targets at various depths within a homogenous scattering medium. We find that the DAC-PS configuration results in superior rejection of multiply scattered background light compared to all other configurations, followed in performance by the SAC-PS, the DAC-LS, and then the SAC-LS. Line scanning with both the DAC and SAC configurations leads to photon crosstalk between pixels. However, at shallow depths, the axial and transverse resolution of all configurations is maintained in a homogeneous scattering medium.

  17. The application of visible wavelength reflectance hyperspectral imaging for the detection and identification of blood stains.

    PubMed

    Li, Bo; Beveridge, Peter; O'Hare, William T; Islam, Meez

    2014-12-01

    Current methods of detection and identification of blood stains rely largely on visual examination followed by presumptive tests such as Kastle-Meyer, Leuco-malachite green or luminol. Although these tests are useful, they can produce false positives and can also have a negative impact on subsequent DNA tests. A novel application of visible wavelength reflectance hyperspectral imaging has been used for the detection and positive identification of blood stains in a non contact and non destructive manner on a range of coloured substrates. The identification of blood staining was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. Images illustrating successful discrimination of blood stains from nine red substances are included. It has also been possible to distinguish between blood and approximately 40 other reddish stains. The technique was also successfully used to detect latent blood stains deposited on white filter paper at dilutions of up to 1 in 512 folds and on red tissue at dilutions of up to 1 in 32 folds. Finally, in a blind trial, the method successfully detected and identified a total of 9 blood stains on a red T-shirt.

  18. Application of a wide-field phantom eye for optical coherence tomography and reflectance imaging

    NASA Astrophysics Data System (ADS)

    Corcoran, Anthony; Muyo, Gonzalo; van Hemert, Jano; Gorman, Alistair; Harvey, Andrew R.

    2015-12-01

    Optical coherence tomography (OCT) and reflectance imaging are used in clinical practice to measure the thickness and transverse dimensions of retinal features. The recent trend towards increasing the field of view (FOV) of these devices has led to an increasing significance of the optical aberrations of both the human eye and the device. We report the design, manufacture and application of the first phantom eye that reproduces the off-axis optical characteristics of the human eye, and allows the performance assessment of wide-field ophthalmic devices. We base our design and manufacture on the wide-field schematic eye, [Navarro, R. J. Opt. Soc. Am. A, 1985, 2.] as an accurate proxy to the human eye and enable assessment of ophthalmic imaging performance for a ? external FOV. We used multi-material 3D-printed retinal targets to assess imaging performance of the following ophthalmic instruments: the Optos 200Tx, Heidelberg Spectralis, Zeiss FF4 fundus camera and Optos OCT SLO and use the phantom to provide an insight into some of the challenges of wide-field OCT.

  19. Applications of Bayesian Procrustes shape analysis to ensemble radar reflectivity nowcast verification

    NASA Astrophysics Data System (ADS)

    Fox, Neil I.; Micheas, Athanasios C.; Peng, Yuqiang

    2016-07-01

    This paper introduces the use of Bayesian full Procrustes shape analysis in object-oriented meteorological applications. In particular, the Procrustes methodology is used to generate mean forecast precipitation fields from a set of ensemble forecasts. This approach has advantages over other ensemble averaging techniques in that it can produce a forecast that retains the morphological features of the precipitation structures and present the range of forecast outcomes represented by the ensemble. The production of the ensemble mean avoids the problems of smoothing that result from simple pixel or cell averaging, while producing credible sets that retain information on ensemble spread. Also in this paper, the full Bayesian Procrustes scheme is used as an object verification tool for precipitation forecasts. This is an extension of a previously presented Procrustes shape analysis based verification approach into a full Bayesian format designed to handle the verification of precipitation forecasts that match objects from an ensemble of forecast fields to a single truth image. The methodology is tested on radar reflectivity nowcasts produced in the Warning Decision Support System - Integrated Information (WDSS-II) by varying parameters in the K-means cluster tracking scheme.

  20. Application of a wide-field phantom eye for optical coherence tomography and reflectance imaging.

    PubMed

    Corcoran, Anthony; Muyo, Gonzalo; van Hemert, Jano; Gorman, Alistair; Harvey, Andrew R

    2015-12-15

    Optical coherence tomography (OCT) and reflectance imaging are used in clinical practice to measure the thickness and transverse dimensions of retinal features. The recent trend towards increasing the field of view (FOV) of these devices has led to an increasing significance of the optical aberrations of both the human eye and the device. We report the design, manufacture and application of the first phantom eye that reproduces the off-axis optical characteristics of the human eye, and allows the performance assessment of wide-field ophthalmic devices. We base our design and manufacture on the wide-field schematic eye, [Navarro, R. J. Opt. Soc. Am. A, 1985,2.] as an accurate proxy to the human eye and enable assessment of ophthalmic imaging performance for a [Formula: see text] external FOV. We used multi-material 3D-printed retinal targets to assess imaging performance of the following ophthalmic instruments: the Optos 200Tx, Heidelberg Spectralis, Zeiss FF4 fundus camera and Optos OCT SLO and use the phantom to provide an insight into some of the challenges of wide-field OCT.

  1. Confocal imaging of mouse mandibular condyle cartilage

    PubMed Central

    He, Y.; Zhang, M.; Huang, A. Y.; Cui, Y.; Bai, D.; Warman, M. L.

    2017-01-01

    Mice are commonly used to study the temporomandibular joint (TMJ) and to model human TMJ disease. However, evaluating TMJ pathology in mice using standard histologic methods is time consuming, labor intensive, and dependent upon investigators’ expertise at consistently orienting and sectioning across tiny specimens. We describe a method that uses confocal microscopy to rapidly and reliably assess indicators of mandibular condyle cartilage pathology in mice. We demonstrate the utility of this method for detecting abnormalities in chondrocyte distribution in mice lacking lubricin (Prg4), the major boundary lubricant of articular cartilage. We further show that the method can provide information about recombination sites and efficiency in mandibular cartilage for Cre-driver strains. Because specimen preparation and data acquisition with confocal microscopy are simple and fast, the method can serve as a primary screening tool for TMJ pathology, before proceeding to complicated, time consuming, secondary analyses. PMID:28266618

  2. In-vivo multi-spectral confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rouse, Andrew R.; Udovich, Joshua A.; Gmitro, Arthur F.

    2005-03-01

    A multi-spectral confocal microendoscope (MCME) for in-vivo imaging has been developed. The MCME employs a flexible fiber-optic catheter coupled to a slit-scan confocal microscope with an imaging spectrometer. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The focus mechanism allows for imaging to a maximum tissue depth of 200 microns. The 3mm diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope. The confocal nature of the system provides optical sectioning with 3 micron lateral resolution and 30 micron axial resolution. The system incorporates two laser sources and is therefore capable of simultaneous acquisition of spectra from multiple dyes using dual excitation. The prism based multi-spectral detection assembly is typically configured to collect 30 spectral samples over the visible range. The spectral sampling rate varies from 4nm/pixel at 490nm to 8nm/pixel at 660nm and the minimum resolvable wavelength difference varies from 8nm to 16nm over the same spectral range. Each of these characteristics are primarily dictated by the dispersion characteristics of the prism. The MCME is designed to examine cellular structures during optical biopsy and to exploit the diagnostic information contained within the spectral domain. The primary applications for the system include diagnosis of disease in the gastro-intestinal tract and female reproductive system. In-vitro, and ex-vivo multi-spectral results are presented.

  3. Probe based confocal laser endomicroscopy of the pancreatobiliary system

    PubMed Central

    Almadi, Majid A; Neumann, Helmut

    2015-01-01

    AIM: To review applications of confocal laser endomicroscopy (CLE) in pancreatobiliary lesions and studies that assessed training and interpretation of images. METHODS: A computerized literature search was performed using OVID MEDLINE, EMBASE, Cochrane library, and the ISI Web of Knowledge from 1980 to October 2014. We also searched abstracts from major meetings that included the Digestive Disease Week, Canadian Digestive Disease Week and the United European Gastroenterology Week using a combination of controlled vocabulary and text words related to pCLE, confocal, endomicroscopy, probe-based confocal laser endomicroscopy, and bile duct to identify reports of trials. In addition, recursive searches and cross-referencing was performed, and manual searches of articles identified after the initial search was also completed. We included fully published articles and those in abstract form. Given the relatively recent introduction of CLE we included randomized trials and cohort studies. RESULTS: In the evaluation of indeterminate pancreatobiliary strictures CLE with ERCP compared to ERCP alone can increase the detection of cancerous strictures with a sensitivity of (98% vs 45%) and has a negative predictive value (97% vs 69%), but decreased the specificity (67% vs 100%) and the positive predictive value (71% vs 100%) when compared to index pathology. Modifications in the classification systems in indeterminate biliary strictures have increased the specificity of pCLE from 67% to 73%. In pancreatic cystic lesions there is a need to develop similar systems to interpret and characterize lesions based on CLE images obtained. The presence of superficial vascular network predicts serous cystadenomas accurately. Also training in acquiring and interpretation of images is feasible in those without any prior knowledge in CLE in a relatively simple manner and computer-aided diagnosis software is a promising innovation. CONCLUSION: The role of pCLE in the evaluation of

  4. Metasurface with Reconfigurable Reflection Phase for High-Power Microwave Applications

    DTIC Science & Technology

    2014-01-07

    Paper 3. DATES COVERED (From - To) 15-08-2012 to 07-01-2014 4. TITLE AND SUBTITLE Metasurface with Reconfigurable Reflection Phase for High- Power...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT We propose a metasurface with reconfigurable reflection phase that can be utilized in high...the metasurface has a reflection phase tuning range of approximately 300 degrees with an associated change in capacitance of 2.7 pF. 15. SUBJECT

  5. Will algorithms modified with soil and weather information improve in-field reflectance-sensing corn nitrogen applications?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrogen (N) needs to support corn (Zea mays L.) production can be highly variable within fields. Canopy reflectance sensing for assessing crop N health has been implemented on many farmers’ fields to side-dress or top-dress variable-rate N application, but at times farmers report the performance of...

  6. High harmonic terahertz confocal gyrotron with nonuniform electron beam

    SciTech Connect

    Fu, Wenjie; Guan, Xiaotong; Yan, Yang

    2016-01-15

    The harmonic confocal gyrotron with nonuniform electron beam is proposed in this paper in order to develop compact and high power terahertz radiation source. A 0.56 THz third harmonic confocal gyrotron with a dual arc section nonuniform electron beam has been designed and investigated. The studies show that confocal cavity has extremely low mode density, and has great advantage to operate at high harmonic. Nonuniform electron beam is an approach to improve output power and interaction efficiency of confocal gyrotron. A dual arc beam magnetron injection gun for designed confocal gyrotron has been developed and presented in this paper.

  7. Materials and corrosion characterization using the confocal resonator

    SciTech Connect

    Tigges, C.P.; Sorensen, N.R.; Hietala, V.M.; Plut, T.A.

    1997-05-01

    Improved characterization and process control is important to many Sandia and DOE programs related to manufacturing. Many processes/structures are currently under-characterized including thin film growth, corrosion and semiconductor structures, such as implant profiles. A sensitive tool is required that is able to provide lateral and vertical imaging of the electromagnetic properties of a sample. The confocal resonator is able to characterize the surface and near-surface impedance of materials. This device may be applied to a broad range of applications including in situ evaluation of thin film processes, physical defect detection/characterization, the characterization of semiconductor devices and corrosion studies. In all of these cases, the technology should work as a real-time process diagnostic or as a feedback mechanism regarding the quality of a manufacturing process. This report summarizes the development and exploration of several diagnostic applications.

  8. Analysis for Mar Vel Black and acetylene soot low reflectivity surfaces for star tracker sunshade applications

    NASA Technical Reports Server (NTRS)

    Yung, E.

    1974-01-01

    Mar Vel Black is a revolutionary new extremely low reflectivity anodized coating developed by Martin Marietta of Denver. It is of great interest in optics in general, and in star trackers specifically because it can reduce extraneous light reflections. A sample of Mar Vel Black was evaluated. Mar Vel Black looks much like a super black surface with many small peaks and very steep sides so that any light incident upon the surface will tend to reflect many times before exiting that surface. Even a high reflectivity surface would thus appear to have a very low reflectivity under such conditions. Conversely, acetylene soot does not have the magnified surface appearance of a super black surface. Its performance is, however, predictable from the surface structure, considering the known configuration of virtually pure carbon.

  9. Characterization and Application of a Grazing Angle Objective for Quantitative Infrared Reflection Microspectroscopy

    NASA Technical Reports Server (NTRS)

    Pepper, Stephen V.

    1995-01-01

    A grazing angle objective on an infrared microspectrometer is studied for quantitative spectroscopy by considering the angular dependence of the incident intensity within the objective's angular aperture. The assumption that there is no angular dependence is tested by comparing the experimental reflectance of Si and KBr surfaces with the reflectance calculated by integrating the Fresnel reflection coefficient over the angular aperture under this assumption. Good agreement was found, indicating that the specular reflectance of surfaces can straight-forwardly be quantitatively integrated over the angular aperture without considering non-uniform incident intensity. This quantitative approach is applied to the thickness determination of dipcoated Krytox on gold. The infrared optical constants of both materials are known, allowing the integration to be carried out. The thickness obtained is in fair agreement with the value determined by ellipsometry in the visible. Therefore, this paper illustrates a method for more quantitative use of a grazing angle objective for infrared reflectance microspectroscopy.

  10. Hexagonal arrays of round-head silicon nanopillars for surface anti-reflection applications

    NASA Astrophysics Data System (ADS)

    Yan, Wensheng; Dottermusch, Stephan; Reitz, Christian; Richards, Bryce S.

    2016-10-01

    We designed and fabricated an anti-reflection surface of hexagonal arrays of round-head silicon nanopillars. The measurements show a significant reduction in reflectivity across a broad spectral range. However, we then grew a conformal titanium dioxide coating via atomic layer deposition to achieve an extremely low weighted average reflection of 2.1% over the 460-1040 nm wavelength range. To understand the underlying reasons for the reduced reflectance, the simulations were conducted and showed that it is due to strong forward scattering of incident light into the silicon substrate. The calculated normalized scattering cross section demonstrates a broadband distribution feature, and the peak has a red-shift to longer wavelengths. Finally, we report two-dimensional weighted average reflectance as a function of both wavelength and angle of incidence and present the resulting analysis contour map.

  11. Study of neutron noise from reflected, metal assemblies with criticality safety applications in mind

    SciTech Connect

    Barnett, C.S.

    1985-08-20

    The author studied the statistics of detected neutrons that leaked from four subcritical reflected, enriched-uranium assemblies, to explore the feasibility of developing a criticality warning system based on neutron noise analysis. The calculated multiplication factors of the assemblies are 0.59, 0.74, 0.82, and 0.92. The author studied three possible discriminators, i.e., three signatures that might be used to discriminate among assemblies of various multiplications. They are: (1) variance-to-mean ratio of the counts in a time bin (V/M); (2) covariance-to-mean ratio of the counts in a common time bin from two different detectors (C/M); and (3) covariance-to-mean ratio of the counts from a single detector in two adjacent time bins of equal length, which the author calls the serial-covariance-to-mean ratio (SC/M). The performances of the three discriminators were not greatly different, but a hierarchy did emerge: SC/M greater than or equal to V/M greater than or equal to C/M. An example of some results: in the neighborhood of k = 0.6 the ..delta..k required for satisfactory discrimination varies from about 3% to 7% as detector solid angle varies from 19% to 5%. In the neighborhood of k = 0.8 the corresponding ..delta..ks are 1% and 2%. The noise analysis techniques studied performed well enough in deeply subcritical situations to deserve testing in an applications environment. They have a good chance of detecting changes in reactivity that are potentially dangerous. One can expect sharpest results when doing comparisons, i.e., when comparing two records, one taken in the past under circumstances known to be normal and one taken now to search for change.

  12. Thermal maturity of Tasmanites microfossils from confocal laser scanning fluorescence microscopy

    USGS Publications Warehouse

    Hackley, Paul C.; Kus, Jolanta

    2015-01-01

    We report here, for the first time, spectral properties of Tasmanites microfossils determined by confocal laser scanning fluorescence microscopy (CLSM, using Ar 458 nm excitation). The Tasmanites occur in a well-characterized natural maturation sequence (Ro 0.48–0.74%) of Devonian shale (n = 3 samples) from the Appalachian Basin. Spectral property λmax shows excellent agreement (r2 = 0.99) with extant spectra from interlaboratory studies which used conventional fluorescence microscopy techniques. This result suggests spectral measurements from CLSM can be used to infer thermal maturity of fluorescent organic materials in geologic samples. Spectra of regions with high fluorescence intensity at fold apices and flanks in individual Tasmanites are blue-shifted relative to less-deformed areas in the same body that have lower fluorescence intensity. This is interpreted to result from decreased quenching moiety concentration at these locations, and indicates caution is needed in the selection of measurement regions in conventional fluorescence microscopy, where it is common practice to select high intensity regions for improved signal intensity and better signal to noise ratios. This study also documents application of CLSM to microstructural characterization of Tasmanites microfossils. Finally, based on an extant empirical relation between conventional λmax values and bitumen reflectance, λmax values from CLSM of Tasmanites microfossils can be used to calculate a bitumen reflectance equivalent value. The results presented herein can be used as a basis to broaden the future application of CLSM in the geological sciences into hydrocarbon prospecting and basin analysis.

  13. Optical clearing assisted confocal microscopy of ex vivo transgenic mouse skin

    NASA Astrophysics Data System (ADS)

    Song, Eunjoo; Ahn, YoonJoon; Ahn, Jinhyo; Ahn, Soyeon; Kim, Changhwan; Choi, Sanghoon; Boutilier, Richard Martin; Lee, Yongjoong; Kim, Pilhan; Lee, Ho

    2015-10-01

    We examined the optical clearing assisted confocal microscopy of the transgenic mouse skin. The pinna and dorsal skin were imaged with a confocal microscope after the application of glycerol and FocusClear. In case of the glycerol-treated pinna, the clearing was minimal due to the inefficient permeability. However, the imaging depth was improved when the pinna was treated with FocusClear. In case of dorsal skin, we were able to image deeply to the subcutaneous connective tissue with both agents. Various skin structures such as the vessel, epithelium cells, cartilage, dermal cells, and hair follicles were clearly imaged.

  14. Identification of focal viral infections by confocal microscopy for subsequent ultrastructural analysis.

    PubMed

    Miller, S E; Levenson, R M; Aldridge, C; Hester, S; Kenan, D J; Howell, D N

    1997-01-01

    A correlative microscopy method for the ultrastructural analysis of focal viral tissue infections is presented. Using a confocal scanning laser microscope, foci of infection are identified in tissue sections prior to embedment; a variety of techniques can be employed for viral detection, including staining with standard histochemical reagents and fluorescently labeled antibodies. Areas of infection identified using confocal microscopy are excised from the tissue sections, embedded, and examined by transmission electron microscopy. Applications of this technique in both diagnostic and basic research settings are described.

  15. Design and Demonstration of a Miniature Catheter for a Confocal Microendoscope

    NASA Astrophysics Data System (ADS)

    Rouse, Andrew R.; Kano, Angelique; Udovich, Joshua A.; Kroto, Shona M.; Gmitro, Arthur F.

    2004-11-01

    The fluorescence confocal microendoscope provides high-resolution, in vivo imaging of cellular pathology during optical biopsy. The confocal microendoscope employs a flexible fiber-optic catheter coupled to a custom-built slit-scan confocal microscope. The catheter consists of a fiber-optic imaging bundle linked to a miniature objective and focus assembly. The 3-mm-diameter catheter may be used on its own or routed though the instrument channel of a commercial endoscope, adding microscopic imaging capability to conventional endoscopy. The design and performance of the miniature objective and focus assembly are discussed. Primary applications of the system include diagnosis of disease in the gastrointestinal tract and female reproductive system.

  16. Crystals and collimators for X-ray spectrometry. [Bragg reflection properties and design for astronomical applications

    NASA Technical Reports Server (NTRS)

    Mckenzie, D. L.; Landecker, P. B.; Underwood, J. H.

    1976-01-01

    Results of the measurement of Bragg reflection properties of crystals suitable for use in X-ray astronomy are presented. Measurements with a double crystal spectrometer were performed on rubidium acid phthalate and thallium acid phthalate to yield values of the integrated reflectivity and diffraction width in the range 8-18 A, and measurements of integrated reflectivity were also performed on ammonium dihydrogen phosphate. The theory and design of an arc-minute range multigrid collimator to be flown on a rocket for solar X-ray studies are also described, along with a method for determining the collimator's X-ray axis.

  17. Reflectance spectroscopy - Quantitative analysis techniques for remote sensing applications. [in planetary surface geology

    NASA Technical Reports Server (NTRS)

    Clark, R. N.; Roush, T. L.

    1984-01-01

    The empirical methods and scattering theories that are important for solving remote sensing problems are among the methods for remotely sensed reflectance data analysis presently compared. In the case of the photon mean optical path length concept's implications for reflectance spectra modeling, it is shown that the mean optical path length in a particulate surface is in roughly inverse proportion to the square root of the absorption coefficient. Absorption bands, which are Gaussian in shape when plotted as true absorptance vs photon energy, are also Gaussians in apparent absorptance, although they have a smaller intensity. An apparent continuum in a reflectance spectrum is modeled as a mathematical function that is used to isolate a particular absorption feature for analysis, and it is noted that this continuum should be removed by dividing it into the reflectance spectrum.

  18. Reflectance spectroscopy: application of the Kubelka-Munk theory to the rates of photoprocesses of powders.

    PubMed

    Simmons, E L

    1976-04-01

    The Kubelka-Munk theory of reflectance spectroscopy is used to derive an approximate equation that describes the rate of the photoprocess of a powdered sample in terms of the remission function. The equation is compared with one obtained using the particle model theory of diffuse reflectance and with experimental data for the photochemical reaction of powdered K(3)[Fe(C(2)O(4))(3)]-3H(2)O.

  19. Detection limits of confocal surface plasmon microscopy

    PubMed Central

    Pechprasarn, Suejit; Somekh, Michael G.

    2014-01-01

    This paper applies rigorous diffraction theory to evaluate the minimum mass sensitivity of a confocal optical microscope designed to excite and detect surface plasmons operating on a planar metallic substrate. The diffraction model is compared with an intuitive ray picture which gives remarkably similar predictions. The combination of focusing the surface plasmons and accurate phase measurement mean that under favorable but achievable conditions detection of small numbers of molecules is possible, however, we argue that reliable detection of single molecules will benefit from the use of structured surfaces. System configurations needed to optimize performance are discussed. PMID:24940537

  20. Applications of shallow high-resolution seismic reflection to various environmental problems

    USGS Publications Warehouse

    Miller, R.D.; Steeples, D.W.

    1994-01-01

    Shallow seismic reflection has been successfully applied to environmental problems in a variety of geologic settings. Increased dynamic range of recording equipment and decreased cost of processing hardware and software have made seismic reflection a cost-effective means of imaging shallow geologic targets. Seismic data possess sufficient resolution in many areas to detect faulting with displacement of less than 3 m and beds as thin as 1 m. We have detected reflections from depths as shallow as 2 m. Subsurface voids associated with abandoned coal mines at depths of less than 20 m can be detected and mapped. Seismic reflection has been successful in mapping disturbed subsurface associated with dissolution mining of salt. A graben detected and traced by seismic reflection was shown to be a preferential pathway for leachate leaking from a chemical storage pond. As shown by these case histories, shallow high-resolution seismic reflection has the potential to significantly enhance the economics and efficiency of preventing and/or solving many environmental problems. ?? 1994.

  1. Diffusion of photoacid generators by laser scanning confocal microscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Ping L.; Webber, Stephen E.; Mendenhall, J.; Byers, Jeffrey D.; Chao, Keith K.

    1998-06-01

    Diffusion of the photogenerated acid during the period of time between exposure and development can cause contrast loss and ultimately loss of the latent image. This is especially relevant for chemically amplified photoresists that require a post-exposure baking step, which in turn facilitates acid diffusion due to the high temperature normally employed. It is thus important to develop techniques with good spatial resolution to monitor the photogeneration of acid. More precisely, we need techniques that provide two distinct types of information: spatial resolution on various length scales within the surface layer and also sufficient depth resolution so that one can observe the transition from very surface layer to bulk structure in the polymer blend coated on silicon substrate. Herein laser scanning confocal microscopy is used to evaluate the resist for the first time. We report the use of the confocal microscopy to map the pag/dye distribution in PHS matrices, with both reflectance images and fluorescence images. A laser beam is focused onto a small 3D volume element, termed a voxel. It is typically 200 nm X 200 nm laterally and 800 nm axially. The illuminated voxel is viewed such that only signals emanating from this voxel are detected, i.e., signal from outside the probed voxel is not detected. By adjusting the vertical position of the laser focal point, the voxel can be moved to the designated lateral plane to produce an image. Contrast caused by topology difference between the exposed and unexposed area can be eliminated. Bis-p-butylphenyl iodonium triflat (7% of polyhydroxystyrene) is used as photoacid generators. 5% - 18% (by weight, PHS Mn equals 13 k) resist in PGMEA solution is spin cast onto the treated quartz disk with thickness of 1.4 micrometers , 5 micrometers space/10 micrometers pitch chrome mask is used to generate the pattern with mercury DUV illumination. Fluoresceinamine, the pH-sensitive dye, is also used to enhance the contrast of

  2. Reflections on current and future applications of multiangle imaging to aerosol and cloud remote sensing

    NASA Astrophysics Data System (ADS)

    Diner, David

    2010-05-01

    The Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global Earth data from NASA's Terra satellite since February 2000. With its 9 along-track view angles, 4 spectral bands, intrinsic spatial resolution of 275 m, and stable radiometric and geometric calibration, no instrument that combines MISR's attributes has previously flown in space, nor is there is a similar capability currently available on any other satellite platform. Multiangle imaging offers several tools for remote sensing of aerosol and cloud properties, including bidirectional reflectance and scattering measurements, stereoscopic pattern matching, time lapse sequencing, and potentially, optical tomography. Current data products from MISR employ several of these techniques. Observations of the intensity of scattered light as a function of view angle and wavelength provide accurate measures of aerosol optical depths (AOD) over land, including bright desert and urban source regions. Partitioning of AOD according to retrieved particle classification and incorporation of height information improves the relationship between AOD and surface PM2.5 (fine particulate matter, a regulated air pollutant), constituting an important step toward a satellite-based particulate pollution monitoring system. Stereoscopic cloud-top heights provide a unique metric for detecting interannual variability of clouds and exceptionally high quality and sensitivity for detection and height retrieval for low-level clouds. Using the several-minute time interval between camera views, MISR has enabled a pole-to-pole, height-resolved atmospheric wind measurement system. Stereo imagery also makes possible global measurement of the injection heights and advection speeds of smoke plumes, volcanic plumes, and dust clouds, for which a large database is now available. To build upon what has been learned during the first decade of MISR observations, we are evaluating algorithm updates that not only refine retrieval

  3. Nondestructive Sectioning Of Fixed And Living Specimens Using A Confocal Scanning Laser Fluorescence Microscope: Microtomoscopy

    NASA Astrophysics Data System (ADS)

    Stelzer, Ernst H...; Wijnaendts-Van-Resandt, Roelof W.

    1987-08-01

    Modern molecular biologists and in particular cell biologists have a large set of experimental tools at their disposal. Immunocytochemistry, fluorescence labels, and microscopy are only subsets of the entire spectrum of methods. Depending on the fields in which biologists work a lot of results are obtained with classical biochemistry, gel electrophoresis and blotting techniques. Gathering morphological data may not be the least important task, but will in many cases be considered only after all other methods have failed. With the advent of video microscopes and the availability of high speed image processing devices, microscopy can also be used for quantitation. Confocal scanning laser fluorescence microscopy (Ft-CSCM) [Cox 1984] is in fact another technique or method that is entering the rapidly developing field of quantitative microscopy. It is therefore very important to understand the physical properties of the CSCLM in detail and to compare a confocal microscope not only with other confocal microscopes, but also with all the other techniques and methods. The confocal microscope has to find its particular application and it should be understood that it will replace neither conventional microscopy, nor video microscopy, nor electron microscopy. It will not be used for every application and every type of investigation. The CSCM has to find its niche in the laboratories and this paper will present two applications in which it proves its usefulness.

  4. Comparison of line-scanned and point-scanned dual-axis confocal microscope performance.

    PubMed

    Wang, D; Chen, Y; Wang, Y; Liu, J T C

    2013-12-15

    The point-scanned dual-axis confocal (PS-DAC) microscope has been shown to exhibit superior capability to reject out-of-focus and multiply scattered light in comparison to its conventional single-axis counterpart. However, the slow frame rate (typically <5 Hz) resulting from point-by-point data collection makes these systems vulnerable to motion artifacts. While video-rate point-scanned confocal microscopy is possible, a line-scanned dual-axis confocal (LS-DAC) microscope provides a simpler means of achieving high-speed imaging through line-by-line data collection, but sacrifices contrast due to loss of confocality along one dimension. Here we evaluate the performance trade-offs between an LS-DAC and PS-DAC microscope with identical spatial resolutions. Characterization experiments of the LS-DAC and PS-DAC microscopes with tissue phantoms, in reflectance mode, are shown to match results from Monte Carlo scattering simulations of the systems. Fluorescence images of mouse brain vasculature, obtained using resolution-matched LS-DAC and PS-DAC microscopes, demonstrate the comparable performance of LS-DAC and PS-DAC microscopy at shallow depths.

  5. Effects of photon reabsorption phenomena in confocal micro-photoluminescence measurements in crystalline silicon

    NASA Astrophysics Data System (ADS)

    Roigé, A.; Alvarez, J.; Jaffré, A.; Desrues, T.; Muñoz, D.; Martín, I.; Alcubilla, R.; Kleider, J.-P.

    2017-02-01

    Confocal micro-photoluminescence (PL) spectroscopy has become a powerful characterization technique for studying novel photovoltaic (PV) materials and structures at the micrometer level. In this work, we present a comprehensive study about the effects and implications of photon reabsorption phenomena on confocal micro-PL measurements in crystalline silicon (c-Si), the workhorse material of the PV industry. First, supported by theoretical calculations, we show that the level of reabsorption is intrinsically linked to the selected experimental parameters, i.e., focusing lens, pinhole aperture, and excitation wavelength, as they define the spatial extension of the confocal detection volume, and therefore, the effective photon traveling distance before collection. Second, we also show that certain sample properties such as the reflectance and/or the surface recombination velocity can also have a relevant impact on reabsorption. Due to the direct relationship between the reabsorption level and the spectral line shape of the resulting PL emission signal, reabsorption phenomena play a paramount role in certain types of micro-PL measurements. This is demonstrated by means of two practical and current examples studied using confocal PL, namely, the estimation of doping densities in c-Si and the study of back-surface and/or back-contacted Si devices such as interdigitated back contact solar cells, where reabsorption processes should be taken into account for the proper interpretation and quantification of the obtained PL data.

  6. Imaging System With Confocally Self-Detecting Laser.

    DOEpatents

    Webb, Robert H.; Rogomentich, Fran J.

    1996-10-08

    The invention relates to a confocal laser imaging system and method. The system includes a laser source, a beam splitter, focusing elements, and a photosensitive detector. The laser source projects a laser beam along a first optical path at an object to be imaged, and modulates the intensity of the projected laser beam in response to light reflected from the object. A beam splitter directs a portion of the projected laser beam onto a photodetector. The photodetector monitors the intensity of laser output. The laser source can be an electrically scannable array, with a lens or objective assembly for focusing light generated by the array onto the object of interest. As the array is energized, its laser beams scan over the object, and light reflected at each point is returned by the lens to the element of the array from which it originated. A single photosensitive detector element can generate an intensity-representative signal for all lasers of the array. The intensity-representative signal from the photosensitive detector can be processed to provide an image of the object of interest.

  7. Reflecting Reflective Practice

    ERIC Educational Resources Information Center

    Galea, Simone

    2012-01-01

    This paper demystifies reflective practice on teaching by focusing on the idea of reflection itself and how it has been conceived by two philosophers, Plato and Irigaray. It argues that reflective practice has become a standardized method of defining the teacher in teacher education and teacher accreditation systems. It explores how practices of…

  8. Line-scanning, stage scanning confocal microscope

    NASA Astrophysics Data System (ADS)

    Carucci, John A.; Stevenson, Mary; Gareau, Daniel

    2016-03-01

    We created a line-scanning, stage scanning confocal microscope as part of a new procedure: video assisted micrographic surgery (VAMS). The need for rapid pathological assessment of the tissue on the surface of skin excisions very large since there are 3.5 million new skin cancers diagnosed annually in the United States. The new design presented here is a confocal microscope without any scanning optics. Instead, a line is focused in space and the sample, which is flattened, is physically translated such that the line scans across its face in a direction perpendicular to the line its self. The line is 6mm long and the stage is capable of scanning 50 mm, hence the field of view is quite large. The theoretical diffraction-limited resolution is 0.7um lateral and 3.7um axial. However, in this preliminary report, we present initial results that are a factor of 5-7 poorer in resolution. The results are encouraging because they demonstrate that the linear array detector measures sufficient signal from fluorescently labeled tissue and also demonstrate the large field of view achievable with VAMS.

  9. Confocal Raman imaging for cancer cell classification

    NASA Astrophysics Data System (ADS)

    Mathieu, Evelien; Van Dorpe, Pol; Stakenborg, Tim; Liu, Chengxun; Lagae, Liesbet

    2014-05-01

    We propose confocal Raman imaging as a label-free single cell characterization method that can be used as an alternative for conventional cell identification techniques that typically require labels, long incubation times and complex sample preparation. In this study it is investigated whether cancer and blood cells can be distinguished based on their Raman spectra. 2D Raman scans are recorded of 114 single cells, i.e. 60 breast (MCF-7), 5 cervix (HeLa) and 39 prostate (LNCaP) cancer cells and 10 monocytes (from healthy donors). For each cell an average spectrum is calculated and principal component analysis is performed on all average cell spectra. The main features of these principal components indicate that the information for cell identification based on Raman spectra mainly comes from the fatty acid composition in the cell. Based on the second and third principal component, blood cells could be distinguished from cancer cells; and prostate cancer cells could be distinguished from breast and cervix cancer cells. However, it was not possible to distinguish breast and cervix cancer cells. The results obtained in this study, demonstrate the potential of confocal Raman imaging for cell type classification and identification purposes.

  10. Ultra-thin anisotropic metasurface for polarized beam splitting and reflected beam steering applications

    NASA Astrophysics Data System (ADS)

    Guo, Wenlong; Wang, Guangming; Li, Tangjing; Li, Haipeng; Zhuang, Yaqiang; Hou, Haisheng

    2016-10-01

    In this paper, we propose a polarization beam splitter utilizing an ultra-thin anisotropic metasurface. The proposed anisotropic element is composed of triple-layered rectangular patches spaced with double-layered dielectric isolators. By tailoring the metallic patches, the cell is capable of transmitting x-polarized waves efficiently and reflecting y-polarized beams with almost 100% efficiency at 15 GHz. In addition to this, the reflected phases can be modulated by adjusting the size of the element, which contributes to beam steering in reflection mode. By assigning gradient phases on the metasurface, the constructed sample has the ability to refract x-polarized waves normally and reflect y-polarized beams anomalously. For verification, a sample with a size of 240 × 240 mm2 is fabricated and measured. Consistent numerical and experimental results have both validated the efficiently anomalous reflection for y-polarized waves and normal refraction for x-polarized beams operating from 14.6-15.4 GHz. Furthermore, the proposed sample has a thickness of 0.1λ at 15 GHz, which provides a promising approach for steering and splitting beams in a compact size.

  11. Quantitative single-molecule imaging by confocal laser scanning microscopy.

    PubMed

    Vukojevic, Vladana; Heidkamp, Marcus; Ming, Yu; Johansson, Björn; Terenius, Lars; Rigler, Rudolf

    2008-11-25

    A new approach to quantitative single-molecule imaging by confocal laser scanning microscopy (CLSM) is presented. It relies on fluorescence intensity distribution to analyze the molecular occurrence statistics captured by digital imaging and enables direct determination of the number of fluorescent molecules and their diffusion rates without resorting to temporal or spatial autocorrelation analyses. Digital images of fluorescent molecules were recorded by using fast scanning and avalanche photodiode detectors. In this way the signal-to-background ratio was significantly improved, enabling direct quantitative imaging by CLSM. The potential of the proposed approach is demonstrated by using standard solutions of fluorescent dyes, fluorescently labeled DNA molecules, quantum dots, and the Enhanced Green Fluorescent Protein in solution and in live cells. The method was verified by using fluorescence correlation spectroscopy. The relevance for biological applications, in particular, for live cell imaging, is discussed.

  12. Improving and Understanding Three Dimensional Spatial Resolution in a Confocal Raman Microscopy and Raman Hyperspectral Imaging I

    NASA Astrophysics Data System (ADS)

    Lee, Eunah; Roussel, Bernard; Froigneux, Emmanuel; Adar, Fran; Mamedov, Sergey; Whitley, Andrew

    2010-08-01

    Confocal Raman microscopy provides a high spatial resolution because it operates in short wavelength region and utilizes confocal optics. However, the spatial resolution of a confocal Raman microscopy is not well understood, and often confused with the smallest measurable sample size. When performing Raman hyperspectral imaging with a confocal Raman microscope, it is also confused with the smallest distance a mapping stage can step. While all these parameters are pertinent to record a good Raman spectrum or a good Raman map, they are not spatial resolution, and thus have different impacts to the data and results. In this and subsequent papers, we will begin with the theoretical definition, examine the instrumental implementations and present the empirical applications of these parameters with examples.

  13. Application of the IMM-JPDA filter to multiple target tracking in total internal reflection fluorescence microscopy images.

    PubMed

    Rezatofighi, Seyed Hamid; Gould, Stephen; Hartley, Richard; Mele, Katarina; Hughes, William E

    2012-01-01

    We propose a multi-target tracking method using an Interacting Multiple Model Joint Probabilistic Data Association (IMM-JPDA) filter for tracking vesicles in total internal reflection fluorescence microscopy (TIRFM) sequences. We enhance the accuracy and reliability of the algorithm by tailoring an appropriate framework to this application. Evaluation of our algorithm is performed on both realistic synthetic data and real TIRFM data. Our results are compared against related methods and a commercial tracking software.

  14. Numerical study of a confocal ultrasonic setup for creation of cavitation

    SciTech Connect

    Lafond, Maxime Chavrier, Françoise; Prieur, Fabrice; Mestas, Jean-Louis; Lafon, Cyril

    2015-10-28

    Acoustic cavitation is used for various therapeutic applications such as local enhancement of drug delivery, histotripsy or hyperthermia. One of the utmost important parameter for cavitation creation is the rarefaction pressure. The typical magnitude of the rarefaction pressure required to initiate cavitation from gas dissolved in tissue is beyond the range of the megapascal. Because nonlinear effects need to be taken into account, a numerical simulator based on the Westervelt equation was used to study the pressure waveform and the acoustic field generated by a setup for creation of cavitation consisting of two high intensity focused ultrasound transducers mounted confocally. At constant acoustic power, simulations with only one and both transducers from the confocal setup showed that the distortion of the pressure waveform due to the combined effects of nonlinearity and diffraction is less pronounced when both confocal transducers are used. Consequently, the confocal setup generates a greater peak negative pressure at focus which is more favorable for cavitation initiation. Comparison between the confocal setup and a single transducer with the same total emitting surface puts in evidence the role of the spatial separation of the two beams. Furthermore, it has been previously shown that the location of the peak negative pressure created by a single transducer shifts from focus towards the transducers in the presence of nonlinear effects. The simulator was used to study a configuration where the acoustical axes of transducers intersect on the peak negative pressure instead of the geometrical focus. For a representative confocal setup, namely moderate nonlinear effects, a 2% increase of the peak negative pressure and 8% decrease of the peak positive pressure resulted from this configuration. These differences tend to increase by increasing nonlinear effects. Although the optimal position of the transducers varies with the nonlinear regimen, the intersection point

  15. In vivo confocal microscopy for the oral cavity: Current state of the field and future potential.

    PubMed

    Maher, N G; Collgros, H; Uribe, P; Ch'ng, S; Rajadhyaksha, M; Guitera, P

    2016-03-01

    Confocal microscopy (CM) has been shown to correlate with oral mucosal histopathology in vivo. The purposes of this review are to summarize what we know so far about in vivo CM applications for oral mucosal pathologies, to highlight some current developments with CM devices relevant for oral applications, and to formulate where in vivo CM could hold further application for oral mucosal diagnosis and management. Ovid Medline® and/or Google® searches were performed using the terms 'microscopy, confocal', 'mouth neoplasms', 'mouth mucosa', 'leukoplakia, oral', 'oral lichen planus', 'gingiva', 'cheilitis', 'taste', 'inflammatory oral confocal', 'mucosal confocal' and 'confocal squamous cell oral'. In summary, inclusion criteria were in vivo use of any type of CM for the human oral mucosa and studies on normal or pathological oral mucosa. Experimental studies attempting to identify proteins of interest and microorganisms were excluded. In total 25 relevant articles were found, covering 8 main topics, including normal oral mucosal features (n=15), oral dysplasia or neoplasia (n=7), inflamed oral mucosa (n=3), taste impairment (n=3), oral autoimmune conditions (n=2), pigmented oral pathology/melanoma (n=1), delayed type hypersensitivity (n=1), and cheilitis glandularis (n=1). The evidence for using in vivo CM in these conditions is poor, as it is limited to mainly small descriptive studies. Current device developments for oral CM include improved probe design. The authors propose that future applications for in vivo oral CM may include burning mouth syndrome, intra-operative mapping for cancer surgery, and monitoring and targeted biopsies within field cancerization.

  16. Particular features of the application of IR reflection spectroscopy methods in studies in archeology and paleontology

    NASA Astrophysics Data System (ADS)

    Zolotarev, V. M.; Khlopachev, G. A.

    2013-06-01

    We have considered an optical model of a porous rough surface with optical properties of objects (bone, flint) that are typical of archeology and paleontology. We have formulated an approach that makes it possible to perform mathematical processing of the IR reflection spectra of objects of this kind using standard algorithms and determine criteria that ensure obtaining reliable information on objects with a rough surface in the course of interpretation of frequencies in their IR reflection spectra. The potential of the approach has been demonstrated using as an example an investigation by the IR Fourier-transform reflection spectroscopy of mineralization processes of mammoth tusks from two paleolithic sites (14000 and 16000 BCE) located by the town of Yudinovo, Bryansk oblast, Russia.

  17. [Application of near infrared reflectance spectroscopy to predict meat chemical compositions: a review].

    PubMed

    Tao, Lin-Li; Yang, Xiu-Juan; Deng, Jun-Ming; Zhang, Xi

    2013-11-01

    In contrast to conventional methods for the determination of meat chemical composition, near infrared reflectance spectroscopy enables rapid, simple, secure and simultaneous assessment of numerous meat properties. The present review focuses on the use of near infrared reflectance spectroscopy to predict meat chemical compositions. The potential of near infrared reflectance spectroscopy to predict crude protein, intramuscular fat, fatty acid, moisture, ash, myoglobin and collagen of beef, pork, chicken and lamb is reviewed. This paper discusses existing questions and reasons in the current research. According to the published results, although published results vary considerably, they suggest that near-infrared reflectance spectroscopy shows a great potential to replace the expensive and time-consuming chemical analysis of meat composition. In particular, under commercial conditions where simultaneous measurements of different chemical components are required, near infrared reflectance spectroscopy is expected to be the method of choice. The majority of studies selected feature-related wavelengths using principal components regression, developed the calibration model using partial least squares and modified partial least squares, and estimated the prediction accuracy by means of cross-validation using the same sample set previously used for the calibration. Meat fatty acid composition predicted by near-infrared spectroscopy and non-destructive prediction and visualization of chemical composition in meat using near-infrared hyperspectral imaging and multivariate regression are the hot studying field now. On the other hand, near infrared reflectance spectroscopy shows great difference for predicting different attributes of meat quality which are closely related to the selection of calibration sample set, preprocessing of near-infrared spectroscopy and modeling approach. Sample preparation also has an important effect on the reliability of NIR prediction; in particular

  18. [Application of near-infrared diffuse reflectance spectroscopy to the detection and identification of transgenic corn].

    PubMed

    Rui, Yu-kui; Luo, Yun-bo; Huang, Kun-lun; Wang, Wei-min; Zhang, Lu-da

    2005-10-01

    With the rapid development of the GMO, more and more GMO food has been pouring into the market. Much attention has been paid to GMO labeling under the controversy of GMO safety. Transgenic corns and their parents were scanned by continuous wave of near infrared diffuse reflectance spectroscopy range of 12000-4000 cm(-1); the resolution was 4 cm(-1); scanning was carried out for 64 times; BP algorithm was applied for data processing. The GMO food was easily resolved. Near-infrared diffuse reflectance spectroscopy is unpolluted and inexpensive compared with PCR and ELISA, so it is a very promising detection method for GMO food.

  19. Confocal imaging of benign and malignant proliferative skin lesions in vivo

    NASA Astrophysics Data System (ADS)

    Gonzalez, Salvador; Rajadhyaksha, Milind M.; Anderson, R. Rox

    1999-06-01

    Near-infrared confocal reflectance microscopy (CM) provides non- invasive real-time images of thin en-face tissue sections with high resolution and contrast. Imaging of cells, nuclei, other organelles, microvessels, and hair follicles has been possible at resolution comparable to standard histology, to a maximum depth of 250-300 μm in human skin in vivo. We have characterized psoriasis as a prototype of benign proliferative skin conditions, and non-pigmented skin malignancies in vivo based on their unstained, native histologic features using CM. Our data shows that reflectance CM may potentially diagnose and morphometrically evaluate proliferative skin lesions in vivo.

  20. An approximate form of the Rayleigh reflection loss and its phase: application to reverberation calculation.

    PubMed

    Harrison, Chris H

    2010-07-01

    A useful approximation to the Rayleigh reflection coefficient for two half-spaces composed of water over sediment is derived. This exhibits dependence on angle that may deviate considerably from linear in the interval between grazing and critical. It shows that the non-linearity can be expressed as a separate function that multiplies the linear loss coefficient. This non-linearity term depends only on sediment density and does not depend on sediment sound speed or volume absorption. The non-linearity term tends to unity, i.e., the reflection loss becomes effectively linear, when the density ratio is about 1.27. The reflection phase in the same approximation leads to the well-known "effective depth" and "lateral shift." A class of closed-form reverberation (and signal-to-reverberation) expressions has already been developed [C. H. Harrison, J. Acoust. Soc. Am. 114, 2744-2756 (2003); C. H. Harrison, J. Comput. Acoust. 13, 317-340 (2005); C. H. Harrison, IEEE J. Ocean. Eng. 30, 660-675 (2005)]. The findings of this paper enable one to convert these reverberation expressions from simple linear loss to more general reflecting environments. Correction curves are calculated in terms of sediment density. These curves are applied to a test case taken from a recent ONR-funded Reverberation Workshop.

  1. Numerical Modeling of Sub-Wavelength Anti-Reflective Structures for Solar Module Applications.

    PubMed

    Han, Katherine; Chang, Chih-Hung

    2014-01-29

    This paper reviews the current progress in mathematical modeling of anti-reflective subwavelength structures. Methods covered include effective medium theory (EMT), finite-difference time-domain (FDTD), transfer matrix method (TMM), the Fourier modal method (FMM)/rigorous coupled-wave analysis (RCWA) and the finite element method (FEM). Time-based solutions to Maxwell's equations, such as FDTD, have the benefits of calculating reflectance for multiple wavelengths of light per simulation, but are computationally intensive. Space-discretized methods such as FDTD and FEM output field strength results over the whole geometry and are capable of modeling arbitrary shapes. Frequency-based solutions such as RCWA/FMM and FEM model one wavelength per simulation and are thus able to handle dispersion for regular geometries. Analytical approaches such as TMM are appropriate for very simple thin films. Initial disadvantages such as neglect of dispersion (FDTD), inaccuracy in TM polarization (RCWA), inability to model aperiodic gratings (RCWA), and inaccuracy with metallic materials (FDTD) have been overcome by most modern software. All rigorous numerical methods have accurately predicted the broadband reflection of ideal, graded-index anti-reflective subwavelength structures; ideal structures are tapered nanostructures with periods smaller than the wavelengths of light of interest and lengths that are at least a large portion of the wavelengths considered.

  2. Being In-Between: Reflecting on Time, Space and Career during the Tenure Application Process

    ERIC Educational Resources Information Center

    Eichler, Mathew

    2015-01-01

    Part of the process of becoming a tenured faculty member is applying for tenure. This reflective essay reports on the period after the submission of tenure materials for review but before the review process for tenure is completed. This is an "in-between" space, where the race of the tenure track is no longer present, but the role of…

  3. Numerical Modeling of Sub-Wavelength Anti-Reflective Structures for Solar Module Applications

    PubMed Central

    Han, Katherine; Chang, Chih-Hung

    2014-01-01

    This paper reviews the current progress in mathematical modeling of anti-reflective subwavelength structures. Methods covered include effective medium theory (EMT), finite-difference time-domain (FDTD), transfer matrix method (TMM), the Fourier modal method (FMM)/rigorous coupled-wave analysis (RCWA) and the finite element method (FEM). Time-based solutions to Maxwell’s equations, such as FDTD, have the benefits of calculating reflectance for multiple wavelengths of light per simulation, but are computationally intensive. Space-discretized methods such as FDTD and FEM output field strength results over the whole geometry and are capable of modeling arbitrary shapes. Frequency-based solutions such as RCWA/FMM and FEM model one wavelength per simulation and are thus able to handle dispersion for regular geometries. Analytical approaches such as TMM are appropriate for very simple thin films. Initial disadvantages such as neglect of dispersion (FDTD), inaccuracy in TM polarization (RCWA), inability to model aperiodic gratings (RCWA), and inaccuracy with metallic materials (FDTD) have been overcome by most modern software. All rigorous numerical methods have accurately predicted the broadband reflection of ideal, graded-index anti-reflective subwavelength structures; ideal structures are tapered nanostructures with periods smaller than the wavelengths of light of interest and lengths that are at least a large portion of the wavelengths considered.

  4. 3D imaging of neutron tracks using confocal microscopy

    NASA Astrophysics Data System (ADS)

    Gillmore, Gavin; Wertheim, David; Flowers, Alan

    2016-04-01

    Neutron detection and neutron flux assessment are important aspects in monitoring nuclear energy production. Neutron flux measurements can also provide information on potential biological damage from exposure. In addition to the applications for neutron measurement in nuclear energy, neutron detection has been proposed as a method of enhancing neutrino detectors and cosmic ray flux has also been assessed using ground-level neutron detectors. Solid State Nuclear Track Detectors (or SSNTDs) have been used extensively to examine cosmic rays, long-lived radioactive elements, radon concentrations in buildings and the age of geological samples. Passive SSNTDs consisting of a CR-39 plastic are commonly used to measure radon because they respond to incident charged particles such as alpha particles from radon gas in air. They have a large dynamic range and a linear flux response. We have previously applied confocal microscopy to obtain 3D images of alpha particle tracks in SSNTDs from radon track monitoring (1). As a charged particle traverses through the polymer it creates an ionisation trail along its path. The trail or track is normally enhanced by chemical etching to better expose radiation damage, as the damaged area is more sensitive to the etchant than the bulk material. Particle tracks in CR-39 are usually assessed using 2D optical microscopy. In this study 6 detectors were examined using an Olympus OLS4100 LEXT 3D laser scanning confocal microscope (Olympus Corporation, Japan). The detectors had been etched for 2 hours 50 minutes at 85 °C in 6.25M NaOH. Post etch the plastics had been treated with a 10 minute immersion in a 2% acetic acid stop bath, followed by rinsing in deionised water. The detectors examined had been irradiated with a 2mSv neutron dose from an Am(Be) neutron source (producing roughly 20 tracks per mm2). We were able to successfully acquire 3D images of neutron tracks in the detectors studied. The range of track diameter observed was between 4

  5. Improving the linearity of infrared diffuse reflection spectroscopy data for quantitative analysis: an application in quantifying organophosphorus contamination in soil.

    PubMed

    Samuels, Alan C; Zhu, Changjiang; Williams, Barry R; Ben-David, Avishai; Miles, Ronald W; Hulet, Melissa

    2006-01-15

    Diffuse reflection data are presented for ethyl methylphosphonate in a fine Utah dirt sample as a model system for organophosphate-contaminated soil. The data revealed a chemometric artifact when the spectra were represented in Kubelka-Munk units that manifests as a linear dependence of spectral peak height on variations in the observed baseline position (i.e., the position of the observed transmission intensity where no absorption features occur in the sample spectrum). We believe that this artifact is the result of the mathematical process by which the raw data are converted into Kubelka-Munk units, and we developed a numerical strategy for compensating for the observed effect and restoring chemometric precision to the diffuse reflection data for quantitative analysis while retaining the benefits of linear calibration afforded by the Kubelka-Munk approach. We validated our Kubelka-Munk correction strategy by repeating the experiment using a simpler system--pure caffeine in potassium bromide. The numerical preprocessing includes conventional multiplicative scatter correction coupled with a baseline offset correction that facilitates the use of quantitative diffuse reflection data in the Kubelka-Munk formalism for the quantitation of contaminants in a complex soil matrix, but is also applicable to more fundamental diffuse reflection quantitative analysis experiments.

  6. Bidirectional Reflectance of Flat, Optically Thick Particulate Layers: An Efficient Radiative Transfer Solution and Applications to Snow and Soil Surfaces

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael I.; Dlugach, Janna M.; Yanovitsku, Edgard G.; Zakharova, Nadia T.

    1999-01-01

    We describe a simple and highly efficient and accurate radiative transfer technique for computing bidirectional reflectance of a macroscopically flat scattering layer composed of nonabsorbing or weakly absorbing, arbitrarily shaped, randomly oriented and randomly distributed particles. The layer is assumed to be homogeneous and optically semi-infinite, and the bidirectional reflection function (BRF) is found by a simple iterative solution of the Ambartsumian's nonlinear integral equation. As an exact Solution of the radiative transfer equation, the reflection function thus obtained fully obeys the fundamental physical laws of energy conservation and reciprocity. Since this technique bypasses the computation of the internal radiation field, it is by far the fastest numerical approach available and can be used as an ideal input for Monte Carlo procedures calculating BRFs of scattering layers with macroscopically rough surfaces. Although the effects of packing density and coherent backscattering are currently neglected, they can also be incorporated. The FORTRAN implementation of the technique is available on the World Wide Web at http://ww,,v.giss.nasa.gov/-crmim/brf.html and can be applied to a wide range of remote sensing, engineering, and biophysical problems. We also examine the potential effect of ice crystal shape on the bidirectional reflectance of flat snow surfaces and the applicability of the Henyey-Greenstein phase function and the 6-Eddington approximation in calculations for soil surfaces.

  7. Research progress of cholesteric liquid crystals with broadband reflection characteristics in application of intelligent optical modulation materials

    NASA Astrophysics Data System (ADS)

    Zhang, Lan-Ying; Gao, Yan-Zi; Song, Ping; Wu, Xiao-Juan; Yuan, Xiao; He, Bao-Feng; Chen, Xing-Wu; Hu, Wang; Guo, Ren-Wei; Ding, Hang-Jun; Xiao, Jiu-Mei; Yang, Huai

    2016-09-01

    Cholesteric liquid crystals (CLCs) have recently sparked an enormous amount of interest in the development of soft matter materials due to their unique ability to self-organize into a helical supra-molecular architecture and their excellent selective reflection of light based on the Bragg relationship. Nowadays, by the virtue of building the self-organized nanostructures with pitch gradient or non-uniform pitch distribution, extensive work has already been performed to obtain CLC films with a broad reflection band. Based on authors’ many years’ research experience, this critical review systematically summarizes the physical and optical background of the CLCs with broadband reflection characteristics, methods to obtain broadband reflection of CLCs, as well as the application in the field of intelligent optical modulation materials. Combined with the research status and the advantages in the field, the important basic and applied scientific problems in the research direction are also introduced. Project supported by the National Natural Science Foundation of China (Grant Nos. 51573006, 51573003, 51203003, 51303008, 51302006, 51402006, 51272026, and 51273022), the Major Project of Beijing Science and Technology Program, China (Grant Nos. Z151100003315023 and Z141100003814011), and the Fok Ying Tung Education Foundation, China (Grant No. 142009).

  8. Research and Development Data to Define the Thermal Performance of Reflective Materials Used to Conserve Energy in Building Applications

    SciTech Connect

    Eisenberg, J

    2001-04-09

    A comprehensive experimental laboratory study has been conducted on the thermal performance of reflective insulation systems. The goal of this study was to develop test and evaluation protocols and to obtain thermal performance data on a selected number of idealized and commercial systems containing reflective airspaces for use in analytical models. Steady-state thermal resistance has been measured on 17 different test panels using two guarded hot boxes. Additional instrumentation was installed to measure the temperature of critical locations inside the test panels. The test parameters which have been studied are heat flow direction (horizontal, up, and down), number of airspaces comprising the cavity, airspace effective emittance, airspace aspect ratio, airspace mean temperature and temperature difference, and the thermal resistance of the stud material. Tests have also been performed on similar constructions with mass insulation. Two one-dimensional calculation techniques (ASHRAE and proposed ASTM) have been employed to determine the cavity thermal resistance from the measured test panel results. The measured cavity thermal resistance is compared with literature data which is commonly employed to calculate the thermal resistance of reflective airspace assemblies. A consumer-oriented handbook pertaining to reflective insulation for building and commercial applications has also been prepared as part of this study.

  9. Confocal Terahertz Imaging of Ancient Manuscripts

    NASA Astrophysics Data System (ADS)

    Flammini, Mariano; Bonsi, Claudia; Ciano, Chiara; Giliberti, Valeria; Pontecorvo, Emanuele; Italia, Paola; DelRe, Eugenio; Ortolani, Michele

    2016-11-01

    Terahertz imaging has the potential to identify and decipher portions of ancient manuscripts, which may be unreadable at infrared and visible wavelengths. We use a scanning confocal terahertz microscope to scan a medieval parchment with music notes and pentagrams written with different inks. The microscope is based on a continuous-wave solid-state source at 0.3 THz, emitting in the free space with a horn antenna, and a high numerical-aperture ellipsoidal reflector. We present terahertz images with diffraction-limited lateral resolution of approximately 0.5 mm, where the different inks all give similar high contrast. Symbols written on the "verso" side of the parchment, barely glimpsed in the near-infrared photograph, leave a clear imprint in the terahertz images. Artifacts due to imperfect flatness of the parchment are also briefly discussed.

  10. Visualizing Cochlear Mechanics Using Confocal Microscopy

    NASA Astrophysics Data System (ADS)

    Ulfendahl, M.; Boutet de Monvel, J.; Fridberger, A.

    2003-02-01

    The sound-evoked vibration pattern of the hearing organ is based on complex mechanical interactions between different cellular structures. To explore the structural changes occurring within the organ of Corti during basilar-membrane motion, stepwise alterations of the scala tympani pressure were applied in an in vitro preparation of the guinea-pig temporal bone. Confocal images were acquired at each pressure level. In this way, the motion of several structures could be simultaneously observed with high resolution in a nearly intact system. Images were analyzed using a novel wavelet-based optical-flow estimation algorithm. Under the present experimental conditions, the reticular lamina moved as a stiff plate with a center of rotation in the region of the inner hair cells. The outer hair cells appeared non-rigid and the basal, synaptic regions of these cells displayed significant radial motion indicative of cellular bending and internal shearing.

  11. Three-dimensional scanning confocal laser microscope

    DOEpatents

    Anderson, R. Rox; Webb, Robert H.; Rajadhyaksha, Milind

    1999-01-01

    A confocal microscope for generating an image of a sample includes a first scanning element for scanning a light beam along a first axis, and a second scanning element for scanning the light beam at a predetermined amplitude along a second axis perpendicular to the first axis. A third scanning element scans the light beam at a predetermined amplitude along a third axis perpendicular to an imaging plane defined by the first and second axes. The second and third scanning element are synchronized to scan at the same frequency. The second and third predetermined amplitudes are percentages of their maximum amplitudes. A selector determines the second and third predetermined amplitudes such that the sum of the percentages is equal to one-hundred percent.

  12. Confocal Terahertz Imaging of Ancient Manuscripts

    NASA Astrophysics Data System (ADS)

    Flammini, Mariano; Bonsi, Claudia; Ciano, Chiara; Giliberti, Valeria; Pontecorvo, Emanuele; Italia, Paola; DelRe, Eugenio; Ortolani, Michele

    2017-04-01

    Terahertz imaging has the potential to identify and decipher portions of ancient manuscripts, which may be unreadable at infrared and visible wavelengths. We use a scanning confocal terahertz microscope to scan a medieval parchment with music notes and pentagrams written with different inks. The microscope is based on a continuous-wave solid-state source at 0.3 THz, emitting in the free space with a horn antenna, and a high numerical-aperture ellipsoidal reflector. We present terahertz images with diffraction-limited lateral resolution of approximately 0.5 mm, where the different inks all give similar high contrast. Symbols written on the "verso" side of the parchment, barely glimpsed in the near-infrared photograph, leave a clear imprint in the terahertz images. Artifacts due to imperfect flatness of the parchment are also briefly discussed.

  13. Confocal reference free traction force microscopy

    PubMed Central

    Bergert, Martin; Lendenmann, Tobias; Zündel, Manuel; Ehret, Alexander E.; Panozzo, Daniele; Richner, Patrizia; Kim, David K.; Kress, Stephan J. P.; Norris, David J.; Sorkine-Hornung, Olga; Mazza, Edoardo; Poulikakos, Dimos; Ferrari, Aldo

    2016-01-01

    The mechanical wiring between cells and their surroundings is fundamental to the regulation of complex biological processes during tissue development, repair or pathology. Traction force microscopy (TFM) enables determination of the actuating forces. Despite progress, important limitations with intrusion effects in low resolution 2D pillar-based methods or disruptive intermediate steps of cell removal and substrate relaxation in high-resolution continuum TFM methods need to be overcome. Here we introduce a novel method allowing a one-shot (live) acquisition of continuous in- and out-of-plane traction fields with high sensitivity. The method is based on electrohydrodynamic nanodrip-printing of quantum dots into confocal monocrystalline arrays, rendering individually identifiable point light sources on compliant substrates. We demonstrate the undisrupted reference-free acquisition and quantification of high-resolution continuous force fields, and the simultaneous capability of this method to correlatively overlap traction forces with spatial localization of proteins revealed using immunofluorescence methods. PMID:27681958

  14. Fluorescence confocal endomicroscopy in biological imaging

    NASA Astrophysics Data System (ADS)

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

    2007-02-01

    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 <1mm diameter to transfer the confocal imaging plane to tissue in intact small animal organs, albeit at lower resolution (30,000 sampling points/image). In rodent models, imaging was performed using various fluorescent staining protocols including fluorescently labelled receptor ligands, labelled antibodies, FITC-dextrans, vital dyes and labelled cells administered topically or intravenously. Abdominal organs of large animals were accessed laparoscopically and contrasted using i.v. fluorescein-sodium. Articular cartilage of sheep and pigs was fluorescently stained with calcein-AM or fluorescein. Surface and sub-surface cellular and

  15. Dual-detection confocal microscopy: high-speed surface profiling without depth scanning

    NASA Astrophysics Data System (ADS)

    Lee, Dong-Ryoung; Gweon, Dae-Gab; Yoo, Hongki

    2016-03-01

    We propose a new method for three-dimensional (3-D) imaging without depth scanning that we refer to as the dual-detection confocal microscopy (DDCM). Compared to conventional confocal microscopy, DDCM utilizes two pinholes of different sizes. DDCM generates two axial response curves which have different stiffness according to the pinhole diameters. The two axial response curves can draw the characteristics curve of the system which shows the relationship between the axial position of the sample and the intensity ratio. Utilizing the characteristic curve, the DDCM reconstructs a 3-D surface profile with a single 2-D scanning. The height of each pixel is calculated by the intensity ratio of the pixel and the intensity ratio curve. Since the height information can be obtained directly from the characteristic curve without depth scanning, a major advantage of DDCM over the conventional confocal microscopy is a speed. The 3-D surface profiling time is dramatically reduced. Furthermore, DDCM can measure 3-D images without the influence of the sample condition since the intensity ratio is independent of the quantum yield and reflectance. We present two types of DDCM, such as a fluorescence microscopy and a reflectance microscopy. In addition, we extend the measurement range axially by varying the pupil function. Here, we demonstrate the working principle of DDCM and the feasibility of the proposed methods.

  16. Development and applications of retro-reflective surfaces for ultrasound in LBE

    SciTech Connect

    2015-07-01

    The Belgian Nuclear Research Centre SCK-CEN is in the process of developing MYRRHA - a fast flux research reactor to replace the aging BR2. MYRRHA is conceptualized as an accelerator driven system cooled by lead bismuth eutectic mixture (LBE). As LBE is opaque to visual light, ultrasonic measurement techniques are employed as the main technology to provide feedback to submerged operations when needed. Conceptually, MYRRHA is a pool type reactor divided in a cold lower plenum and hot upper plenum separated by a diaphragm that forces the main flow through the core. The main flow is cooled by four heat exchangers and driven by two liquid metal pumps. One of the tasks tackled using ultrasound is locating a potentially lost fuel assembly to assist a recovery operation. As all fuel manipulations in MYRRHA are performed in the lower plenum, a potentially lost fuel assembly is located in the lower plenum. Buoyancy will force the lost fuel assembly to float against the diaphragm unless it is still partially inserted in the core. Because of the latter situation, an ultrasonic scan localizing the fuel assembly should be performed from a large distance to avoid a collision with such a partially inserted fuel assembly. Unfortunately, standard machined stainless steel objects, such as a fuel assembly, reflect an ultrasonic pulse in a specular way which induces stringent requirements on the alignment of the ultrasonic sensor with respect to the fuel assembly as we cannot rely on diffuse reflections and/or scattering of the ultrasonic pulse. Moreover, increasing the distance also increases geometric spreading and absorption of the pulse weakening the signal amplitude even faster to noise levels when deviating from perfect alignment. An alternative approach consists in relying on reflections from the known surroundings: a lost fuel assembly will block the line-of-sight to the diaphragm resulting in an anomaly in the reflection - either a shorter than expected time-of-flight of the

  17. Near-infrared reflectance spectra-applications to problems in asteroid-meteorite relationships

    NASA Technical Reports Server (NTRS)

    Mcfadden, Lucy A.; Chamberlin, Alan; Vilas, Faith

    1991-01-01

    Near-infrared spectral reflectance data were collected at the Infrared Telescope Facility (IRTF) at Mauna Kea Observatories in 1985 and 1986 for the purpose of searching the region near the 3:1 Kirkwood gap for asteroids with the spectral signatures of ordinary chondrite parent bodies. Twelve reflectance spectra are observed. The presence of ordinary chondrite parent bodies among this specific set of observed asteroids is not obvious, though the sample is biased towards the larger asteroids in the region due to limitations imposed by detector sensitivity. The data set, which was acquired with the same instrumentation used for the 52-color asteroid survey (Bell et al., 1987), also presents some additional findings. The range of spectral characteristics that exist among asteroids of the same taxonomic type is noted. Conclusions based on the findings are discussed.

  18. Application of the Total Reflection X-ray Fluorescence technique to trace elements determination in tobacco

    NASA Astrophysics Data System (ADS)

    Martinez, T.; Lartigue, J.; Zarazua, G.; Avila-Perez, P.; Navarrete, M.; Tejeda, S.

    2008-12-01

    Many studies have identified an important number of toxic elements along with organic carcinogen molecules and radioactive isotopes in tobacco. In this work we have analyzed by Total Reflection X-Ray Fluorescence 9 brands of cigarettes being manufactured and distributed in the Mexican market. Two National Institute of Standards and Technology standards and a blank were equally treated at the same time. Results show the presence of some toxic elements such as Pb and Ni. These results are compared with available data for some foreign brands, while their implications for health are discussed. It can be confirmed that the Total Reflection X-Ray Fluorescence method provides precise (reproducible) and accuracy (trueness) data for 15 elements concentration in tobacco samples.

  19. Optimization and application of reflective LSPR optical fiber biosensors based on silver nanoparticles.

    PubMed

    Chen, Jiangping; Shi, Se; Su, Rongxin; Qi, Wei; Huang, Renliang; Wang, Mengfan; Wang, Libing; He, Zhimin

    2015-05-26

    In this study, we developed a reflective localized surface plasmon resonance (LSPR) optical fiber sensor, based on silver nanoparticles (Ag NPs). To enhance the sensitivity of the LSPR optical sensor, two key parameters were optimized, the length of the sensing area and the coating time of the Ag NPs. A sensing length of 1.5 cm and a 1-h coating time proved to be suitable conditions to produce highly sensitive sensors for biosensing. The optimized sensor has a high refractive index sensitivity of 387 nm/RIU, which is much higher than that of other reported individual silver nanoparticles in solutions. Moreover, the sensor was further modified with antigen to act as a biosensor. Distinctive wavelength shifts were found after each surface modification step. In addition, the reflective LSPR optical fiber sensor has high reproducibility and stability.

  20. Application of transcutaneous diffuse reflectance spectroscopy in the measurement of blood glucose concentration

    NASA Astrophysics Data System (ADS)

    Chen, Wenliang; Liu, Rong; Cui, Houxin; Xu, Kexin; Lv, Lina

    2004-07-01

    In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/l, respectively.

  1. Accurate Sizing of Nanoparticles Using Confocal Correlation Spectroscopy

    PubMed Central

    Kuyper, Christopher L.; Fujimoto, Bryant S.; Zhao, Yiqiong; Schiro, Perry G.; Chiu, Daniel T.

    2008-01-01

    The ability to size accurately low concentrations of nanoscale particles in small volumes is useful for a broad range of disciplines. Here, we characterize confocal correlation spectroscopy (CCS), which is capable of measuring sizes of both fluorescent and non-fluorescent particles, such as quantum dots, gold colloids, latex spheres, and fluorescent beads. We measured accurately particles ranging in diameter from 11 nm to 300 nm, a size range that had been difficult to probe, owing to a phenomenon coined biased diffusion that causes diffusion times, or particle size, to deviate as a function of laser power. At low powers, artifacts mimicking biased diffusion are caused by saturation of the detector, which is especially problematic when probing highly fluorescent or highly scattering nanoparticles. At higher powers (>1 mW), however, autocorrelation curves in both resonant and non-resonant conditions show a structure indicative of an increased contribution from longer correlation times coupled with a decrease in shorter correlation times. We propose this change in the autocorrelation curve is due to partial trapping of the particles as they transit the probe volume. Furthermore, we found only a slight difference in the effect of biased diffusion when comparing resonant and non-resonant conditions. Simulations suggest the depth of trapping potential necessary for biased diffusion is >1 kBT. Overcoming artifacts from detector saturation and biased diffusion, confocal correlation spectroscopy is particularly advantageous due to its ability to size particles in small volumes characteristic of microfluidic channels and aqueous microdroplets. We believe the method will find increasing use in a wide range of applications in measuring nanoparticles and macromolecular systems. PMID:17134198

  2. Confocal bioimaging the living cornea with autofluorescence and specific fluorescent probes

    NASA Astrophysics Data System (ADS)

    Masters, Barry R.; Paddock, Stephen W.

    1990-08-01

    Confocal bioimaging of the fine structure of the living rabbit cornea with both reflected light and fluorescent light has been demonstrated with a laser scanning confocal imaging system. Kalman averaging was used to reduce the noise in the images. Superficial epithelial, basal epithelial cells, stromal keratocytes, and endothelial cells were imaged. These cells and their subcellular structures were imaged in the two modes for comparison. The superficial epithelial cells were imaged by their autofluorescence (488/520 nm). This fluorescence signal may be due to the mitochondrial flavoproteins and can be used as a noninvasive indicator of cellular oxidative function. Thiazole orange was used to stain cell nuclei for fluorescence imaging. DiOC6 was used to stain the endoplasmic reticulum for fluorescence imaging. Fluorescein- conjugated phalloidin was used to stain actin for fluorescence imaging.

  3. Advances in far-ultraviolet reflective and transmissive coatings for space applications

    NASA Astrophysics Data System (ADS)

    Rodríguez-de Marcos, Luis; Aznárez, José A.; Méndez, José A.; Larruquert, Juan I.; Vidal-Dasilva, M.; Malvezzi, A. Marco; Giglia, Angelo; Capobianco, Gerardo; Massone, Giuseppe; Fineschi, Silvano; Nannarone, Stefano

    2016-07-01

    Exploitation of far ultraviolet (FUV, 100-200 nm) observations extends to most areas of modern astronomy, from detailed observations of Solar System objects, the interstellar medium, exoplanets, stars and galaxies, to studies of crucial cosmological relevance. Despite several developments in recent decades, yet many observations are not possible due to technical limitations, of which one of the most important is the lack of optical coatings with high throughput. Development and optimization of such efficient FUV coatings have been identified in several roadmap reports as a key goal for future missions. The success of this development will ultimately improve the performance of nowadays feasible optical instruments and will enable new scientific imaging capabilities. GOLD's research is devoted to developing novel coatings with enhanced performance for space optics. Several deposition systems are available for the deposition of multilayer coatings. A deposition system was developed to deposit FUV coatings to satisfy space requirements. It consists of a 75-cm-diameter deposition chamber pumped with a cryo-pump and placed in an ISO-6 clean room. This chamber is available for deposition by evaporation of top-requirement coatings such as Al/ MgF2 mirrors or (Al/MgF2)n multilayer coatings for transmittance filters. A plan to add an Ion-Beam-Sputtering system in this chamber is under way. In this and other chambers at GOLD the following FUV coatings can be prepared: Transmittance filters based on (Al/MgF2)n multilayer coatings. These filters can be designed to have a peak at the FUV spectral line or band of interest and a high peak-to-visible transmittance ratio. Filters can be designed with a peak transmittance at a wavelength as short as 120 nm and with a transmittance in the visible smaller than 10-5. Narrowband reflective coatings peaked close to H Lyman β (102.6 nm) with a reflectance at H Lyman α (121.6 nm) two orders of magnitude below the one at 102.6 nm. Other

  4. Total reflection X-ray fluorescence trace mercury determination by trapping complexation: Application in advanced oxidation technologies

    NASA Astrophysics Data System (ADS)

    Custo, Graciela; Litter, Marta I.; Rodríguez, Diana; Vázquez, Cristina

    2006-11-01

    It is well known that Hg species cause high noxious effects on the health of living organisms even at very low levels (5 μg/L). Quantification of this element is an analytical challenge due to the peculiar physicochemical properties of all Hg species. The regulation of the maximal allowable Hg concentration led to search for sensitive methods for its determination. Total reflection X-ray fluorescence is a proved instrumental analytical tool for the determination of trace elements. In this work, the use of total reflection X-ray fluorescence for Hg quantification is investigated. However, experimental determination by total reflection X-ray fluorescence requires depositing a small volume of sample on the reflector and evaporation of the solvent until dryness to form a thin film. Because of volatilization of several Hg forms, a procedure to capture these volatile species in liquid samples by using complexing agents is proposed. Acetate, oxalic acid, ethylenediaminetetracetic acid and ammonium pyrrolidine-dithiocarbamate were assayed for trapping the analytes into the solution during the preparation of the sample and onto the reflector during total reflection X-ray fluorescence measurements. The proposed method was applied to evaluate Hg concentration during TiO 2-heterogeneous photocatalysis, one of the most known advanced oxidation technologies. Advanced oxidation technologies are processes for the treatment of effluents in waters and air that involve the generation of very active oxidative and reductive species. In heterogeneous photocatalysis, Hg is transformed to several species under ultraviolet illumination in the presence of titanium dioxide. Total reflection X-ray fluorescence was demonstrated to be applicable in following the extent of the heterogeneous photocatalysis reaction by determining non-transformed Hg in the remaining solution.

  5. CONFOCAL LASER SCANNING MICROSCOPY OF RAT FOLLICLE DEVELOPMENT

    EPA Science Inventory

    This study used confocal laser scanning microscopy (CLSM) to study follicular development in millimeter pieces of rat ovary. To use this technology, it is essential to stain the tissue before laser excitation with the confocal microscope. Various fluorescent stains (Yo-Pro, Bo-Pr...

  6. Evaluation and purchase of confocal microscopes: Numerous factors to consider

    EPA Science Inventory

    The purchase of a confocal microscope can be a complex and difficult decision for an individual scientist, group or evaluation committee. This is true even for scientists that have used confocal technology for many years. The task of reaching the optimal decision becomes almost i...

  7. Simultaneous Confocal Scanning Laser Ophthalmoscopy Combined with High-Resolution Spectral-Domain Optical Coherence Tomography: A Review

    PubMed Central

    Castro Lima, Verônica; Rodrigues, Eduardo B.; Nunes, Renata P.; Sallum, Juliana F.; Farah, Michel E.; Meyer, Carsten H.

    2011-01-01

    We aimed to evaluate technical aspects and the clinical relevance of a simultaneous confocal scanning laser ophthalmoscope and a high-speed, high-resolution, spectral-domain optical coherence tomography (SDOCT) device for retinal imaging. The principle of confocal scanning laser imaging provides a high resolution of retinal and choroidal vasculature with low light exposure. Enhanced contrast, details, and image sharpness are generated using confocality. The real-time SDOCT provides a new level of accuracy for assessment of the angiographic and morphological correlation. The combined system allows for simultaneous recordings of topographic and tomographic images with accurate correlation between them. Also it can provide simultaneous multimodal imaging of retinal pathologies, such as fluorescein and indocyanine green angiographies, infrared and blue reflectance (red-free) images, fundus autofluorescence images, and OCT scans (Spectralis HRA + OCT; Heidelberg Engineering, Heidelberg, Germany). The combination of various macular diagnostic tools can lead to a better understanding and improved knowledge of macular diseases. PMID:22132313

  8. MEMS-BASED 3D CONFOCAL SCANNING MICROENDOSCOPE USING MEMS SCANNERS FOR BOTH LATERAL AND AXIAL SCAN

    PubMed Central

    Liu, Lin; Wang, Erkang; Zhang, Xiaoyang; Liang, Wenxuan; Li, Xingde; Xie, Huikai

    2014-01-01

    A fiber-optic 3D confocal scanning microendoscope employing MEMS scanners for both lateral and axial scan was designed and constructed. The MEMS 3D scan engine achieved a lateral scan range of over ± 26° with a 2D MEMS scanning micromirror and a depth scan of over 400 μm with a 1D MEMS tunable microlens. The lateral resolution and axial resolution of this system were experimentally measured as 1.0 μm and 7.0 μm, respectively. 2D and 3D confocal reflectance images of micro-patterns, micro-particles, onion skins and acute rat brain tissue were obtained by this MEMS-based 3D confocal scanning microendoscope. PMID:25013304

  9. Three-dimensional reconstruction from multiple reflected views within a realist painting: an application to Scott Fraser's "Three way vanitas"

    NASA Astrophysics Data System (ADS)

    Smith, Brandon M.; Stork, David G.; Zhang, Li

    2009-01-01

    The problem of reconstructing a three-dimensional scene from single or multiple views has been thoroughly studied in the computer vision literature, and recently has been applied to problems in the history of art. Criminisi pioneered the application of single-view metrology to reconstructing the fictive spaces in Renaissance paintings, such as the vault in Masaccio's Trinità and the plaza in Piero della Francesca's Flagellazione. While the vast majority of realist paintings provide but a single view, some provide multiple views, through mirrors depicted within their tableaus. The contemporary American realist Scott Fraser's Three way vanitas is a highly realistic still-life containing three mirrors; each mirror provides a new view of the objects in the tableau. We applied multiple-view reconstruction methods to the direct image and the images reflected by these mirrors to reconstruct the three-dimensional tableau. Our methods estimate virtual viewpoints for each view using the geometric constraints provided by the direct view of the mirror frames, along with the reflected images themselves. Moreover, our methods automatically discover inconsistencies between the different views, including ones that might elude careful scrutiny by eye, for example the fact that the height of the water in the glass differs between the direct view and that in the mirror at the right. We believe our work provides the first application of multiple-view reconstruction to a single painting and will have application to other paintings and questions in the history of art.

  10. Quantification of confocal images of biofilms grown on irregular surfaces

    PubMed Central

    Ross, Stacy Sommerfeld; Tu, Mai Han; Falsetta, Megan L.; Ketterer, Margaret R.; Kiedrowski, Megan R.; Horswill, Alexander R.; Apicella, Michael A.; Reinhardt, Joseph M.; Fiegel, Jennifer

    2014-01-01

    Bacterial biofilms grow on many types of surfaces, including flat surfaces such as glass and metal and irregular surfaces such as rocks, biological tissues and polymers. While laser scanning confocal microscopy can provide high-resolution images of biofilms grown on any surface, quantification of biofilm-associated bacteria is currently limited to bacteria grown on flat surfaces. This can limit researchers studying irregular surfaces to qualitative analysis or quantification of only the total bacteria in an image. In this work, we introduce a new algorithm called modified connected volume filtration (MCVF) to quantify bacteria grown on top of an irregular surface that is fluorescently labeled or reflective. Using the MCVF algorithm, two new quantification parameters are introduced. The modified substratum coverage parameter enables quantification of the connected-biofilm bacteria on top of the surface and on the imaging substratum. The utility of MCVF and the modified substratum coverage parameter were shown with Pseudomonas aeruginosa and Staphylococcus aureus biofilms grown on human airway epithelial cells. A second parameter, the percent association, provides quantified data on the colocalization of the bacteria with a labeled component, including bacteria within a labeled tissue. The utility of quantifying the bacteria associated with the cell cytoplasm was demonstrated with Neisseria gonorrhoeae biofilms grown on cervical epithelial cells. This algorithm provides more flexibility and quantitative ability to researchers studying biofilms grown on a variety of irregular substrata. PMID:24632515

  11. Gold nanoparticles sensing with diffusion reflection measurement as a new medical diagnostics application

    NASA Astrophysics Data System (ADS)

    Fixler, Dror

    2014-02-01

    The ability to quantitatively and noninvasively detect nanoparticles in vivo has important implications on their development as optical sensors for medical diagnostics. We suggest a new method for cancer detection based on diffusion reflection (DR) measurements of gold nanorods (GNR). In our talk, the ability to extract optical properties of phantoms and their GNR concentrations from DR measurements will demonstrate. We will report, for the first time, GNR detection through upper tissue-like phantom layers, as well as the detection of a tumor presented as highly concentrated GNR placed deep within a phantom.

  12. Beamforming with a volumetric array of massless laser spark sources--Application in reflection tracking.

    PubMed

    Eskelinen, Joona; Hæggström, Edward; Delikaris-Manias, Symeon; Bolaños, Javier Gómez; Pulkki, Ville

    2015-06-01

    A volumetric array of laser-induced air breakdown sparks is used to produce a directional and steerable acoustic source. The laser breakdown array element is broadband, point-like, and massless. It produces an impulse-like waveform in midair, thus generating accurate spatio-temporal information for acoustic beamforming. A laser-spark scanning setup and the concept of a massless steerable source are presented and evaluated with a cubic array by using an off-line far field delay-and-sum beamforming method. This virtual acoustic array with minimal source influence can, for instance, produce narrow transmission beams to obtain localized and directional impulse response information by reflection tracking.

  13. Fabrication of highly transparent diamond-like carbon anti-reflecting coating for Si solar cell application

    SciTech Connect

    Banerjee, Amit Das, Debajyoti

    2014-04-24

    ARC grade highly transparent unhydrogenated diamond-like carbon (DLC) films were produced, directly from a-C target, using RF magnetron sputtering deposition technique, for optoelectronic applications. Optical band gap, transmittance, reflectance, sp{sup 3} fraction, I{sub D}/I{sub G}, density, and refractive index of the films have been estimated with the help of optical tools like Uv-vis spectrophotometer, ellipsometer and micro-Raman. Optimum ARC-qualities have been identified in low-temperature grown DLC films at an Ar pressure of 4 mTorr in the reactor, accomplishing its key requirements for use in silicon solar cells.

  14. Resonant loop mirror with narrow-band reflections and its application in single-frequency fiber lasers

    SciTech Connect

    Paschotta, R.; Brinck, D.J.; Farwell, S.G.; Hanna, D.C.

    1997-01-01

    We present a new form of loop mirror (to be realized with all-fiber or integrated optics technology) that can produce narrow-band reflections and could find an application in single-frequency fiber lasers, allowing for a standing-wave design with a long doped section and eliminating the need for a Faraday isolator or a fiber grating. We discuss the main features of such a loop mirror and present experimental results that agree well with the theory. {copyright} 1997 Optical Society of America

  15. A Generic Approach for Inversion of Surface Reflectance over Land: Overview, Application and Validation Using MODIS and LANDSAT8 Data

    NASA Technical Reports Server (NTRS)

    Vermote, E.; Roger, J. C.; Justice, C. O.; Franch, B.; Claverie, M.

    2016-01-01

    This paper presents a generic approach developed to derive surface reflectance over land from a variety of sensors. This technique builds on the extensive dataset acquired by the Terra platform by combining MODIS and MISR to derive an explicit and dynamic map of band ratio's between blue and red channels and is a refinement of the operational approach used for MODIS and LANDSAT over the past 15 years. We will present the generic approach and the application to MODIS and LANDSAT data and its validation using the AERONET data.

  16. Simulation of attenuated total reflection infrared absorbance spectra: applications to automotive clear coat forensic analysis.

    PubMed

    Lavine, Barry K; Fasasi, Ayuba; Mirjankar, Nikhil; Nishikida, Koichi; Campbell, Jay

    2014-01-01

    Attenuated total reflection (ATR) is a widely used sampling technique in infrared (IR) spectroscopy because minimal sample preparation is required. Since the penetration depth of the ATR analysis beam is quite shallow, the outer layers of a laminate or multilayered paint sample can be preferentially analyzed with the entire sample intact. For this reason, forensic laboratories are taking advantage of ATR to collect IR spectra of automotive paint systems that may consist of three or more layers. However, the IR spectrum of a paint sample obtained by ATR will exhibit distortions, e.g., band broadening and lower relative intensities at higher wavenumbers, compared with its transmission counterpart. This hinders library searching because most library spectra are measured in transmission mode. Furthermore, the angle of incidence for the internal reflection element, the refractive index of the clear coat, and surface contamination due to inorganic contaminants can profoundly influence the quality of the ATR spectrum obtained for automotive paints. A correction algorithm to allow ATR spectra to be searched using IR transmission spectra of the paint data query (PDQ) automotive database is presented. The proposed correction algorithm to convert transmission spectra from the PDQ library to ATR spectra is able to address distortion issues such as the relative intensities and broadening of the bands, and the introduction of wavelength shifts at lower frequencies, which prevent library searching of ATR spectra using archived IR transmission data.

  17. Dye-enhanced multimodal confocal microscopy for noninvasive detection of skin cancers in mouse models

    NASA Astrophysics Data System (ADS)

    Park, Jesung; Mroz, Pawel; Hamblin, Michael R.; Yaroslavsky, Anna N.

    2010-03-01

    Skin cancer is the most common form of human cancer. Its early diagnosis and timely treatment is of paramount importance for dermatology and surgical oncology. In this study, we evaluate the use of reflectance and fluorescence confocal microscopy for detecting skin cancers in an in-vivo trial with B16F10 melanoma and SCCVII squamous cell carcinoma in mice. For the experiments, the mice are anesthetized, then the tumors are infiltrated with aqueous solution of methylene blue and imaged. Reflectance images are acquired at 658 nm. Fluorescence is excited at 658 nm and registered in the range between 690 and 710 nm. After imaging, the mice are sacrificed. The tumors are excised and processed for hematoxylin and eosin histopathology, which is compared to the optical images. The results of the study indicate that in-vivo reflectance images provide valuable information on vascularization of the tumor, whereas the fluorescence images mimic the structural features seen in histopathology. Simultaneous dye-enhanced reflectance and fluorescence confocal microscopy shows promise for the detection, demarcation, and noninvasive monitoring of skin cancer development.

  18. Transmissive grating-reflective mirror-based fiber optic accelerometer for stable signal acquisition in industrial applications

    NASA Astrophysics Data System (ADS)

    Lee, Yeon-Gwan; Kim, Dae-Hyun; Kim, Chun-Gon

    2012-05-01

    This paper discusses an applicable fiber-optic accelerometer composed of a transmissive grating panel, a reflection mirror, and two optical fibers with a separation of quarter grating pitch as transceivers that monitor the low-frequency accelerations of civil engineering structures. This sensor structure brings together the advantages of both a simple sensor structure, which leads to simplified cable design by 50% in comparison with the conventional transmission-type fiber optic accelerometer, and a stable reflected signals acquisition with repeatability in comparison to the researched grating-reflection type fiber optic accelerometer. The vibrating displacement and sinusoidal acceleration measured from the proposed fiber optic sensor demonstrated good agreement with those of a commercial laser displacement sensor and a MEMS accelerometer without electromagnetic interference. The developed fiber optic accelerometer can be used in frequency ranges below 4.0 Hz with a margin of error that is less than 5% and a high sensitivity of 5.06 rad/(m/s)2.

  19. Anti-resonant reflecting guidance in alcohol-filled hollow core photonic crystal fiber for sensing applications.

    PubMed

    Liu, Shuhui; Wang, Ying; Hou, Maoxiang; Guo, Jiangtao; Li, Zhihua; Lu, Peixiang

    2013-12-16

    Mechanism and sensing applications of antiresonant reflecting guidance in an alcohol-filled simplified hollow-core (SHC) photonic crystal fiber (PCF) are demonstrated. By filling one air hole in the air cladding of the PCF with alcohol, anti-resonant reflecting guidance of light can be achieved and energy leakage of the core modes can be induced at resonant wavelengths of the Fabry-Pérot (F-P) resonator formed by the alcohol-filled layer combined with the silica cladding in the cross-section of the PCF. The proposed structure exhibits periodic lossy dips in the transmission spectrum, of which the visibilities are sensitive to the refractive index of surrounding medium due to the reflectivity variation of the F-P resonator. Water level sensing is experimentally realized with this principle and the lossy dip exhibits a linear decrease against water level with a sensitivity of 1.1 dB/mm. The sensor is also sensitive to environmental temperature and a temperature sensitivity of -0.48 nm/°C is obtained between room temperature and 60 °C.

  20. Critical Reflectance Derived from MODIS: Application for the Retrieval of Aerosol Absorption over Desert Regions

    NASA Technical Reports Server (NTRS)

    Wells, Kelley C.; Martins, J. Vanderlei; Remer, Lorraine A.; Kreidenweis, Sonia M.; Stephens, Graeme L.

    2012-01-01

    Aerosols are tiny suspended particles in the atmosphere that scatter and absorb sunlight. Smoke particles are aerosols, as are sea salt, particulate pollution and airborne dust. When you look down at the earth from space sometimes you can see vast palls of whitish smoke or brownish dust being transported by winds. The reason that you can see these aerosols is because they are reflecting incoming sunlight back to the view in space. The reason for the difference in color between the different types of aerosol is that the particles arc also absorbing sunlight at different wavelengths. Dust appears brownish or reddish because it absorbs light in the blue wavelengths and scatters more reddish light to space, Knowing how much light is scattered versus how much is absorbed, and knowin that as a function of wavelength is essential to being able to quantify the role aerosols play in the energy balance of the earth and in climate change. It is not easy measuring the absorption properties of aerosols when they are suspended in the atmosphere. People have been doing this one substance at a time in the laboratory, but substances mix when they are in the atmosphere and the net absorption effect of all the particles in a column of air is a goal of remote sensing that has not yet been completely successful. In this paper we use a technique based on observing the point at which aerosols change from brightening the surface beneath to darkening it. If aerosols brighten a surface. they must scatter more light to space. If they darken the surface. they must be absorbing more. That cross over point is called the critical reflectance and in this paper we show that critical reflectance is a monotonic function of the intrinsic absorption properties of the particles. This parameter we call the single scattering albedo. We apply the technique to MODIS imagery over the Sahara and Sahel regions to retrieve the single scattering albedo in seven wavelengths, compare these retrievals to ground

  1. Photonic topological insulators and their applications: from delay lines to reflections-free resonators (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Shvets, Gennady B.

    2016-09-01

    Electromagnetic (EM) waves propagating through an inhomogeneous medium inevitably scatter whenever the medium's electromagnetic properties change on the scale of a single wavelength. This fundamental phenomenon constrains how optical structures are designed and interfaced with each other. Recent theoretical work indicates that electromagnetic structures collectively known as photonic topological insulators (PTIs) can be employed to overcome this fundamental limitation, thereby paving the way for ultra-compact photonic structures that no longer have to be wavelength-scale smooth. I will review some of the recent developments in the field of topological photonics and discuss several novel directions. Those include the first experimental realization of the topologically robust (i.e. reflections- and interference-free) delay line that enables nearly-arbitrary engineering of the optical phase along the light's path. Novel concepts such as all-dielectric PTIs that emulate the valley degree of freedom, as well as topologically protected high-Q cavities will also be discussed.

  2. Application of ultraviolet reflectivity measurements from Nimbus-7 to determine cloud amount

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K.; Eck, T. F.; Hwang, P. H.; Stowe, L. L.

    1983-01-01

    A technique is described that uses scene reflectivity derived from the Total Ozone Mapping Spectrometer (TOMS) measurements from aboard the Nimbus-7 satellite to improve the estimation of cloud amounts from the data taken by the Temperature Humidity IR Radiometer (THIR) onboard the same satellite. TOMS operates in six 1 nm wide spectral bands in the UV (380, 360, 340, 331, 318, and 313 nm) and provides information for inference of directional albedos. Moreover, the features of the TOMS images are paralleled with those obtained by the Geostationary Operational Environmental Satellite (GEOS) visible images. It is noted that by use of such a multisensor approach relatively thin or broken low clouds (below 2 km) can be detected with an rms error of about 10 percent when compared to the GOES visible and IR images.

  3. First application of proton reflection magnetometry with MESSENGER to estimate Mercury's surface magnetic field strength (Invited)

    NASA Astrophysics Data System (ADS)

    Winslow, R. M.; Johnson, C. L.; Anderson, B. J.; Gershman, D. J.; Raines, J. M.; Lillis, R. J.; Korth, H.; Slavin, J. A.; Solomon, S. C.

    2013-12-01

    We present the first use of proton reflection magnetometry, a novel adaptation of electron reflectometry, to estimate Mercury's surface field strength. We use measurements of protons by MESSENGER's Fast Imaging Plasma Spectrometer (FIPS) in 8-s integration times. Because of the limited field of view of FIPS, we average pitch-angle distributions by accumulating proton data from multiple integration periods and orbits over selected geographical regions. Proton loss cones are evident in both the northern hemisphere cusp region as well as on the nightside at low latitudes in the southern hemisphere. The existence of the loss cones provides confirmation of proton precipitation to the surface in these regions. The loss cone pitch-angle cut-offs are gradual rather than sharp, which we attribute in part to wave-particle scattering causing pitch-angle diffusion. Fitting diffusion curves to the pitch-angle distributions yields estimates of both the cut-off pitch angle, αc, and an average Dαt, where Dα is the pitch-angle diffusion coefficient and t is the diffusion time. The in-situ magnetic field together with αc provide an estimate of the surface magnetic field strength. The results are within 10% of a magnetospheric model for the surface field at the mapped surface locations, but are systematically lower than the model predictions. This discrepancy is consistent with the presence of near-surface plasma, which locally lowers the actual total magnetic field at the surface but is not included in the vacuum-field magnetospheric model. As consistency checks, we have confirmed that the loss cone size decreases with increasing altitude and that the surface magnetic field strength increases with increasing latitude. Our results confirm the offset dipole structure at the surface and demonstrate that proton reflection magnetometry is a practical method for inferring the surface magnetic field strength at Mercury. Further observations may resolve regional-scale structure in the

  4. Historical perspective and modern applications of Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR).

    PubMed

    Blum, Marc-Michael; John, Harald

    2012-01-01

    Vibrational spectroscopy has a long history as an important spectroscopic method in chemical and pharmaceutical analysis. Instrumentation for infrared (IR) spectroscopy was revolutionized by the introduction of Fourier Transform Infrared (FTIR) spectrometers. In addition, easier sampling combined with better sample-to-sample reproducibility and user-to-user spectral variation became available with attenuated total reflectance (ATR) probes and their application for in situ IR spectroscopy. These innovations allow many new applications in chemical and pharmaceutical analysis, such as the use of IR spectroscopy in Process Analytical Chemistry (PAC), the quantitation of drugs in complex matrix formulations, the analysis of protein binding and function and in combination with IR microscopy to the emergence of IR imaging technologies. The use of ATR-FTIR instruments in forensics and first response to 'white powder' incidents is also discussed. A short overview is given in this perspective article with the aim to renew and intensify interest in IR spectroscopy.

  5. Deep stroma investigation by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Rossi, Francesca; Tatini, Francesca; Pini, Roberto; Valente, Paola; Ardia, Roberta; Buzzonetti, Luca; Canovetti, Annalisa; Malandrini, Alex; Lenzetti, Ivo; Menabuoni, Luca

    2015-03-01

    Laser assisted keratoplasty is nowadays largely used to perform minimally invasive surgery and partial thickness keratoplasty [1-3]. The use of the femtosecond laser enables to perform a customized surgery, solving the specific problem of the single patient, designing new graft profiles and partial thickness keratoplasty (PTK). The common characteristics of the PTKs and that make them eligible respect to the standard penetrating keratoplasty, are: the preservation of eyeball integrity, a reduced risk of graft rejection, a controlled postoperative astigmatism. On the other hand, the optimal surgical results after these PTKs are related to a correct comprehension of the deep stroma layers morphology, which can help in the identification of the correct cleavage plane during surgeries. In the last years some studies were published, giving new insights about the posterior stroma morphology in adult subjects [4,5]. In this work we present a study performed on two groups of tissues: one group is from 20 adult subjects aged 59 +/- 18 y.o., and the other group is from 15 young subjects, aged 12+/-5 y.o.. The samples were from tissues not suitable for transplant in patients. Confocal microscopy and Environmental Scanning Electron Microscopy (ESEM) were used for the analysis of the deep stroma. The preliminary results of this analysis show the main differences in between young and adult tissues, enabling to improve the knowledge of the morphology and of the biomechanical properties of human cornea, in order to improve the surgical results in partial thickness keratoplasty.

  6. Silicon-based reflective polymer-dispersed LC display for portable low-power applications

    NASA Astrophysics Data System (ADS)

    Van Doorselaer, Geert P. S.; Carchon, Nadine; Van den Steen, Jean; Cuypers, Dieter; Vanfleteren, Jan M.; De Smet, Herbert; Van Calster, Andre

    1999-03-01

    Recently LCOS microdisplays are becoming available for personal IT applications, despite some problems which are less critical in poly silicon or amorphous silicon based displays. The most common problems which must be encountered are the polarization of the pixels and the light shielding of the silicon substrate. In this paper a methods proposed which solves the light shielding and pixel flatness problem. A non-critical back-end processing which can be applied outside the silicon foundry has been developed. The effectiveness of the light shielding on a working demonstrator display is shown. To avoid light losses caused by a polarization filter, a polymer dispersed LC has been chosen. By decreasing the cell gap we made the PDLC voltage compatible with a standard 3 micrometers CMOS process and its response fast enough to be used for video applications. It is shown that this choice is very suited in direct view and portable applications. The realized prototype has 3 bit grey levels and is video compatible and can be used in a number of applications, such as personal viewers, PDAs and data displays.

  7. Retrieving the optical parameters of biological tissues using diffuse reflectance spectroscopy and Fourier series expansions. I. theory and application.

    PubMed

    Muñoz Morales, Aarón A; Vázquez Y Montiel, Sergio

    2012-10-01

    The determination of optical parameters of biological tissues is essential for the application of optical techniques in the diagnosis and treatment of diseases. Diffuse Reflection Spectroscopy is a widely used technique to analyze the optical characteristics of biological tissues. In this paper we show that by using diffuse reflectance spectra and a new mathematical model we can retrieve the optical parameters by applying an adjustment of the data with nonlinear least squares. In our model we represent the spectra using a Fourier series expansion finding mathematical relations between the polynomial coefficients and the optical parameters. In this first paper we use spectra generated by the Monte Carlo Multilayered Technique to simulate the propagation of photons in turbid media. Using these spectra we determine the behavior of Fourier series coefficients when varying the optical parameters of the medium under study. With this procedure we find mathematical relations between Fourier series coefficients and optical parameters. Finally, the results show that our method can retrieve the optical parameters of biological tissues with accuracy that is adequate for medical applications.

  8. Estimating the water content of geologic materials using near-infrared reflectance spectroscopy: Applications to laboratory and spacecraft data

    NASA Astrophysics Data System (ADS)

    Milliken, Ralph Edward

    Visible-near infrared reflectance spectroscopy has been used to relate the absorption strength of the 3 micrometer hydration feature to absolute water content (weight percent) of hydrated geologic materials. Complicating factors of albedo, particle size, and composition were examined individually. Laboratory results combining spectral measurements of materials under ambient, low relative humidity, and heated conditions with measurements of water content provide a method to link changes in band strength to changes in water content for materials under varying hydration states. Primary results indicate that reflectance spectra should be converted to single scattering albedo in order to accurately estimate water content for a wide variety of clay minerals, sulfates, zeolites, and hydrated volcanic materials. These methods are applicable to both laboratory and remotely sensed reflectance spectra. Application of our hydration model to high-resolution Mars Express OMEGA spectra of the martian surface reveal that bright and dark regions have similar water contents in the equatorial latitudes (2--4 wt. %), hydration increases with latitude poleward of ˜60°N (up to 8--15 wt. %), and local outcrops of sulfate and phyllosilicate material exhibit water contents of 5--8 wt. %. Furthermore, high latitude surfaces exhibit seasonal changes in water content on the order of 2--3 wt. %, likely the result of water vapor exchange between the regolith and atmosphere. The methods and model presented here provide a robust, non-destructive technique for estimating the water content of particulate samples spanning a wide albedo range (0.07--0.9), particle size (<250 mum), and composition (well-ordered to poorly crystalline). Applying these models to laboratory samples and spacecraft data will provide insight into the hydration state of terrestrial and planetary materials and the location, amount, and role of water in the solar system under current and past conditions.

  9. Reflections on clinical applications of yoga in voice therapy with MTD.

    PubMed

    Moore, Carmelle

    2012-12-01

    This paper explores the application of modified yoga techniques, as an adjunct to voice therapy, by a speech pathologist who is also a yoga teacher. Yoga practices, with effects that may be short-term, are not considered a substitute for comprehensive and integrated somatic retraining systems (such as the Alexander Technique or Feldenkrais ATM). However, when yoga is conducted emphasizing kinaesthetic and proprioceptive awareness, the client may achieve an 'awareness state' that facilitates the learning of vocal remediation techniques (for example, by more easily 'tuning in' to the subtle sensations of supralaryngeal deconstriction). Core yoga elements and clinical applications are identified. The potential benefits and considerations when using yoga as an adjunct to the treatment of muscle tension dysphonia (MTD) are explored.

  10. Penetration of resin-based materials into initial erosion lesion: A confocal microscopic study.

    PubMed

    Ionta, Franciny Querobim; Boteon, Ana Paula; Moretto, Marcelo Juliano; Júnior, Odair Bim; Honório, Heitor Marques; Silva, Thiago Cruvinel; Wang, Linda; Rios, Daniela

    2016-02-01

    The application of resin-based materials is an alternative of treatment for eroded lesions. Nevertheless, there are no studies about the penetration of these materials into eroded lesion, which might affect its adhesion. Therefore, this study evaluated the penetration of four resin-based materials, with and without enamel etching. By using an in vitro protocol, types of treatment were studied at five levels (AdheSE(®) , Tetric N-Bond(®) , Single Bond 2(®) , Helioseal Clear(®) , Icon(®) ) and types of enamel etching in two levels (with and without). Materials were stained with 0.02 mg/mL ethanolic solution of tetramethylrhodamine isothiocyanate. Bovine enamel samples (4 × 4 mm) were immersed in 0.01 M HCl, pH 2.3, for 30 seconds to produce initial eroded lesions. Afterward, the materials were applied on half of sample enamel surface following the manufacturer's instructions. On the other half of sample, the materials were applied without etching the enamel. Materials penetration into the enamel was assessed by Confocal Laser Scanning Microscopy on reflection and fluorescence modes. The penetration depth (PD) was measured using ImageJ software. Data were analyzed by two-way ANOVA and Tukey test (P < 0.05). Regardless of the material, etched enamel resulted in higher PD than non-etched (P < 0.05). Icon(®) showed the highest PD in enamel followed by Helioseal Clear(®) (P < 0.05), with significant difference between them (P < 0.05) and no difference was found among AdheSE(®) , Tetric N-Bond(®) , and Single Bond 2(®) (P > 0.05). It can be concluded that prior enamel etching increased the materials penetration into eroded enamel and the Icon(®) -infiltrant presented highest penetration.

  11. Confocal Microscopy of Unfixed Breast Needle Core Biopsies: A Comparison to Fixed and Stained Sections

    PubMed Central

    2009-01-01

    Background Needle core biopsy, often in conjunction with ultrasonic or stereotactic guided techniques, is frequently used to diagnose breast carcinoma in women. Confocal scanning laser microscopy (CSLM) is a technology that provides real-time digital images of tissues with cellular resolution. This paper reports the progress in developing techniques to rapidly screen needle core breast biopsy and surgical specimens at the point of care. CSLM requires minimal tissue processing and has the potential to reduce the time from excision to diagnosis. Following imaging, specimens can still be submitted for standard histopathological preparation. Methods Needle core breast specimens from 49 patients were imaged at the time of biopsy. These lesions had been characterized under the Breast Imaging Reporting And Data System (BI-RADS) as category 3, 4 or 5. The core biopsies were imaged with the CSLM before fixation. Samples were treated with 5% citric acid and glycerin USP to enhance nuclear visibility in the reflectance confocal images. Immediately following imaging, the specimens were fixed in buffered formalin and submitted for histological processing and pathological diagnosis. CSLM images were then compared to the standard histology. Results The pathologic diagnoses by standard histology were 7 invasive ductal carcinomas, 2 invasive lobular carcinomas, 3 ductal carcinomas in-situ (CIS), 21 fibrocystic changes/proliferative conditions, 9 fibroadenomas, and 5 other/benign; two were excluded due to imaging difficulties. Morphologic and cellular features of benign and cancerous lesions were identified in the confocal images and were comparable to standard histologic sections of the same tissue. Conclusion CSLM is a technique with the potential to screen needle core biopsy specimens in real-time. The confocal images contained sufficient information to identify stromal reactions such as fibrosis and cellular proliferations such as intra-ductal and infiltrating carcinoma, and

  12. Calculation of confocal microscope images of cholesteric blue phases

    NASA Astrophysics Data System (ADS)

    Fukuda, Jun-ichi; Okumura, Yasushi; Kikuchi, Hirotsugu

    2016-03-01

    Real-space images of bulk cholesteric blue phases (BPs) have been successfully obtained by confocal microscopy observations using structural color without doping fluorescent dye. However, theoretical interpretation of these images (for example, the understanding of the relation between intensity distribution and the ordering of BPs) remains challenging because typical lattice spacing of BPs is of the order of the wavelength of visible light, and therefore geometrical optics is entirely useless. In this work, we present a numerical approach to calculate the confocal images of BPs by solving the Maxwell equations. Calculated confocal images are consistent with experimental observations in terms of in-plane symmetry.

  13. Terahertz interferometric synthetic aperture tomography for confocal imaging systems.

    PubMed

    Heimbeck, M S; Marks, D L; Brady, D; Everitt, H O

    2012-04-15

    Terahertz (THz) interferometric synthetic aperture tomography (TISAT) for confocal imaging within extended objects is demonstrated by combining attributes of synthetic aperture radar and optical coherence tomography. Algorithms recently devised for interferometric synthetic aperture microscopy are adapted to account for the diffraction-and defocusing-induced spatially varying THz beam width characteristic of narrow depth of focus, high-resolution confocal imaging. A frequency-swept two-dimensional TISAT confocal imaging instrument rapidly achieves in-focus, diffraction-limited resolution over a depth 12 times larger than the instrument's depth of focus in a manner that may be easily extended to three dimensions and greater depths.

  14. Near infrared reflectance spectra: Applications to problems in asteroid-meteorite relationships

    NASA Technical Reports Server (NTRS)

    Mcfadden, Lucy A.; Chamberlin, Alan B.

    1992-01-01

    An observing program designed to search for evidence of ordinary chondrite parent bodies near the 3:1 Kirkwood Gap was carried out in 1985 and 1986. Studies by Wisdom (1985), Wetherill (1985), and subsequent work by Milani et al. (1989) indicate that the 3:1 Kirkwood gap is the most probable source region for the majority of ordinary chondrite meteorites. The diversity of the reflectance spectra among this small data set is surprising. Early work by Gaffey and McCord (1978) showed that the inner region of the main asteroid belt is dominated by high albedo objects with mafic silicate surfaces. One would expect to see mostly spectra with 1- and 2-micron absorption bands based on this earlier work. Only 5 (of 12) spectra have these expected features. The distribution of taxonomic types presented by Gradie and Tedesco (1982) is in most cases a useful simplification of the compositional structure of the asteroid belt. The range of spectral characteristics seen with higher resolution in the near-IR has not been previously reported and is not represented in the standard asteroid taxonomy. Near-IR spectra contain valuable mineralogical information which enhances knowledge of the composition and structure of asteroids.

  15. Applicability of diffusion approximation in analysis of diffuse reflectance spectra from healthy human skin

    NASA Astrophysics Data System (ADS)

    Naglič, Peter; Vidovič, Luka; Milanič, Matija; Randeberg, Lise L.; Majaron, Boris

    2013-11-01

    Measurement of diffuse reflectance spectra (DRS) is a common experimental approach for non-invasive determination of tissue optical properties, as well as objective monitoring of various tissue malformations. Propagation of light in scattering media is often treated in diffusion approximation (DA). The major advantage of this approach is that it leads to enclosed analytical solutions for tissues with layered structure, which includes human skin. Despite the fact that DA solutions were shown to be inaccurate near tissue boundaries, the practicality of this approach makes it quite popular, especially when attempting extraction of specific chromophore concentrations from measured DRS. In this study we analyze the discrepancies between DRS spectra as obtained by using the DA solutions for three-layer skin model and more accurate predictions from Monte Carlo (MC) modeling. Next, we analyze the artifacts which result from the above discrepancies when extracting the parameters of skin structure and composition by fitting the DA solutions to the MC spectra. The reliability and usefulness of such a fit is then tested also on measurements of seasonal changes in otherwise healthy human skin.

  16. Variational modelling of extreme waves through oblique interaction of solitary waves: application to Mach reflection

    NASA Astrophysics Data System (ADS)

    Gidel, Floriane; Bokhove, Onno; Kalogirou, Anna

    2017-01-01

    In this work, we model extreme waves that occur due to Mach reflection through the intersection of two obliquely incident solitary waves. For a given range of incident angles and amplitudes, the Mach stem wave grows linearly in length and amplitude, reaching up to 4 times the amplitude of the incident waves. A variational approach is used to derive the bidirectional Benney-Luke equations, an asymptotic equivalent of the three-dimensional potential-flow equations modelling water waves. This nonlinear and weakly dispersive model has the advantage of allowing wave propagation in two horizontal directions, which is not the case with the unidirectional Kadomtsev-Petviashvili (KP) equation used in most previous studies. A variational Galerkin finite-element method is applied to solve the system numerically in Firedrake with a second-order Störmer-Verlet temporal integration scheme, in order to obtain stable simulations that conserve the overall mass and energy of the system. Using this approach, we are able to get close to the 4-fold amplitude amplification predicted by Miles.

  17. Determination of element levels in human serum: Total reflection X-ray fluorescence applications

    NASA Astrophysics Data System (ADS)

    Majewska, U.; Łyżwa, P.; Łyżwa, K.; Banaś, D.; Kubala-Kukuś, A.; Wudarczyk-Moćko, J.; Stabrawa, I.; Braziewicz, J.; Pajek, M.; Antczak, G.; Borkowska, B.; Góźdź, S.

    2016-08-01

    Deficiency or excess of elements could disrupt proper functioning of the human body and could lead to several disorders. Determination of their concentrations in different biological human fluids and tissues should become a routine practice in medical treatment. Therefore the knowledge about appropriate element concentrations in human organism is required. The purpose of this study was to determine the concentration of several elements (P, S, Cl, K, Ca, Cr, Fe, Cu, Zn, Se, Br, Rb, Pb) in human serum and to define the reference values of element concentration. Samples of serum were obtained from 105 normal presumably healthy volunteers (66 women aged between 15 and 78 years old; 39 men aged between 15 and 77 years old). Analysis has been done for the whole studied population and for subgroups by sex and age. It is probably first so a wide study of elemental composition of serum performed in the case of Świętokrzyskie region. Total reflection X-ray fluorescence (TXRF) method was used to perform the elemental analysis. Spectrometer S2 Picofox (Bruker AXS Microanalysis GmbH) was used to identify and measure elemental composition of serum samples. Finally, 1st and 3rd quartiles were accepted as minimum and maximum values of concentration reference range.

  18. Laser scanning confocal microscope with programmable amplitude, phase, and polarization of the illumination beam.

    PubMed

    Boruah, B R; Neil, M A A

    2009-01-01

    We describe the design and construction of a laser scanning confocal microscope with programmable beam forming optics. The amplitude, phase, and polarization of the laser beam used in the microscope can be controlled in real time with the help of a liquid crystal spatial light modulator, acting as a computer generated hologram, in conjunction with a polarizing beam splitter and two right angled prisms assembly. Two scan mirrors, comprising an on-axis fast moving scan mirror for line scanning and an off-axis slow moving scan mirror for frame scanning, configured in a way to minimize the movement of the scanned beam over the pupil plane of the microscope objective, form the XY scan unit. The confocal system, that incorporates the programmable beam forming unit and the scan unit, has been implemented to image in both reflected and fluorescence light from the specimen. Efficiency of the system to programmably generate custom defined vector beams has been demonstrated by generating a bottle structured focal volume, which in fact is the overlap of two cross polarized beams, that can simultaneously improve both the lateral and axial resolutions if used as the de-excitation beam in a stimulated emission depletion confocal microscope.

  19. 3D image reconstruction using optical sectioning in confocal scanning microscopy

    NASA Astrophysics Data System (ADS)

    Seo, Jungwoo; Kang, Dong Kyun; Park, Sunglim; Gweon, Dae gab

    2001-10-01

    Confocal scanning microscopy (CSM) has been used in biological application, materials science, semiconductor quality measurement and other non-destructive microscopic application. Small spot of light illuminates a sample, and a small detector that is ideally a point detector collects the reflected or transmitted light having the information of specimen. An image distribution can be reconstructed by a correlation analysis of spots with the high bandwidth. The mechanism for two-dimensional beam scanning and optical sectioning has an important role in CSM as the three-dimensional profiler. The parasitic motion of focus on the detector gives rise to the fatal distortion of an image profile named the extinction effect while using acousto-optical (AO) deflector. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. We propose the progressive methods for the high quality image as the following. At first, for having the corrected image, small spot and long scan range, this paper shows that the optimal design having the multi-objects can be used by choosing the unitary lens device in CSM. At second, in order to compensate for the intensity cancellation at the end profile that may be the cause of waviness for the optical image, this paper shows that it is efficient to schedule the frequency of scan. According to characteristics of the extinction curve and axial/lateral response having the error property, we can define the frequency and sensitivity of as their robustness. Finally, the axial response gives an important motive for the optical section, and the limit of

  20. Microelectrophoresis of Silica Rods Using Confocal Microscopy

    PubMed Central

    2017-01-01

    The electrophoretic mobility and the zeta potential (ζ) of fluorescently labeled colloidal silica rods, with an aspect ratio of 3.8 and 6.1, were determined with microelectrophoresis measurements using confocal microscopy. In the case where the colloidal particles all move at the same speed parallel to the direction of the electric field, we record a xyz-stack over the whole depth of the capillary. This method is faster and more robust compared to taking xyt-series at different depths inside the capillary to obtain the parabolic flow profile, as was done in previous work from our group. In some cases, rodlike particles do not move all at the same speed in the electric field, but exhibit a velocity that depends on the angle between the long axis of the rod and the electric field. We measured the orientation-dependent velocity of individual silica rods during electrophoresis as a function of κa, where κ–1 is the double layer thickness and a is the radius of the rod associated with the diameter. Thus, we determined the anisotropic electrophoretic mobility of the silica rods with different sized double layers. The size of the double layer was tuned by suspending silica rods in different solvents at different electrolyte concentrations. We compared these results with theoretical predictions. We show that even at already relatively high κa when the Smoluchowski limiting law is assumed to be valid (κa > 10), an orientation dependent velocity was measured. Furthermore, we observed that at decreasing values of κa the anisotropy in the electrophoretic mobility of the rods increases. However, in low polar solvents with κa < 1, this trend was reversed: the anisotropy in the electrophoretic mobility of the rods decreased. We argue that this decrease is due to end effects, which was already predicted theoretically. When end effects are not taken into account, this will lead to strong underestimation of the experimentally determined zeta potential. PMID:28045541

  1. Correcting spaceborne reflectivity measurements for application in solar ultraviolet radiation levels calculations at ground level

    NASA Astrophysics Data System (ADS)

    den Outer, P. N.; van Dijk, A.; Slaper, H.; Lindfors, A. V.; de Backer, H.; Bais, A. F.; Feister, U.; Koskela, T.; Josefsson, W.

    2012-01-01

    The Lambertian Equivalent Reflection (LER) produced by satellite-carried instruments is used to determine cloud effects on ground level UltraViolet (UV) radiation. The focus is on data use from consecutive operating instruments: the Total Ozone Mapping Spectrometers (TOMS) flown on Nimbus 7 from 1979 to 1992, TOMS on Earth Probe from 1996 to 2005, and the Ozone Monitoring Instrument (OMI) flown on Aura since 2004. The LER data produced by TOMS on Earth Probe is only included until 2002. The possibility to use the Radiative Cloud Fraction (RCF)-product of OMI is also investigated. A comparison is made with cloud effects inferred from ground-based pyranometer measurements at over 83 World Radiation Data Centre stations. Modelled UV irradiances utilizing LER data are compared with measurements of UV irradiances at eight European low elevation stations. The LER data set of the two TOMS instruments shows a consistent agreement, and the required corrections are of low percentage i.e. 2-3%. In contrast, the LER data of OMI requires correction of 7-10%, and a solar angle dependency therein is more pronounced. These corrections were inferred from a comparison with pyranometer data, and tested using the UV measurements. The RCF product of OMI requires a large correction but can then be implemented as a cloud effect proxy. However, a major drawback of RCF is the large number of clipped data, i.e. 18%, and results are not better than those obtained with the corrected LER product of OMI. The average reduction of UV radiation due to clouds for all sites together indicate a small trend: a diminishing cloudiness, in line with ground-based UV observations. Uncorrected implementation of LER would have indicated the opposite. An optimal field of view of 1.25° was established for LER data to calculate UV radiations levels. The corresponding area can be traversed within 5-7 h at the average wind speeds found for the West European continent.

  2. In vivo confocal microscopy of meibomian glands in primary blepharospasm

    PubMed Central

    Lin, Tong; Gong, Lan

    2016-01-01

    Abstract The aim of the study was to evaluate the morphological changes of meibomian glands (MGs) in primary blepharospasm (PBS) by in vivo laser scanning confocal microscopy (LSCM) and to investigate the correlations between clinical data of PBS and LSCM parameters of MGs. This prospective and case–control study recruited 30 consecutive PBS patients and 30 age- and gender-matched healthy controls. After questionnaire assessments of ocular surface disease index (OSDI), Jankovic rating scale, and blepharospasm disability index, all subjects underwent blink rate evaluation, tear film break-up time (TBUT), corneal fluorescein staining (CFS), Schirmer test, MG expressibility, meibum quality, MG dropout, and LSCM examination of the MGs. The main LSCM outcomes included the mean MG acinar area and density, orifice diameter, meibum secretion reflectivity, acinar irregularity, and inhomogeneity of interstice and acinar wall. The PBS patients had significantly higher blink rate, higher OSDI and CFS scores, lower TBUT and Schirmer test value, and worse MG expressibility than the controls (All P < 0.05), whereas meibum quality showed no difference (P > 0.05). The PBS patients showed lower values of MG acinar area, orifice diameter and meibum secretion reflectivity, and higher scores of acinar irregularity and inhomogeneity of interstices than the controls (All P < 0.05). For the PBS patients, the severity of blepharospasm evaluated by JCR scale was strong correlated with MG acinar area (P < 0.001), orifice diameter (P = 0.002), meibum secretion reflectivity (P = 0.002), and MG acinar irregularity (P = 0.013). The MG expressibility was significantly correlated to MG acinar area (P = 0.039), orifice diameter (P < 0.001), and MG acinar irregularity (P = 0.014). The OSDI score was moderate correlated with MG acinar irregularity (P = 0.016), whereas the TBUT value was positively correlated with MG acinar area (P = 0.045) and negatively correlated to MG acinar

  3. Personal reflections on the highlights and changes in radiation and radioisotope measurement applications

    NASA Astrophysics Data System (ADS)

    Gardner, Robin P.; Lee, Kyoung O.

    2015-11-01

    This paper describes the recent changes that the authors have perceived in the use of radiation and radioisotope measurement applications. The first change is that due to the increased use of Monte Carlo simulation which has occurred from a normal evolutionary process. This is due in large part to the increased accuracy that is being obtained by the use of detector response functions (DRFs) and the simultaneous increased computational efficiency that has become available with these DRFs, the availability of a greatly improved weight windows variance reduction method, and the availability of inexpensive computer clusters. This first change is a happy one. The other change that is occurring is in response to recent terrorist activities. That change is the replacement or major change in the use of long-lived radioisotopes in radioisotope measurement and other radioisotope source applications. In general this can be done by improving the security of these radioisotope sources or by replacing them altogether by using machine sources of radiation. In either case one would like to preclude altogether or at least minimize the possibility of terrorists being able to obtain radioisotopes and use them for clandestine purposes.

  4. Confocal and dermoscopic features of basal cell carcinoma in Gorlin-Goltz syndrome: A case report.

    PubMed

    Casari, Alice; Argenziano, Giuseppe; Moscarella, Elvira; Lallas, Aimilios; Longo, Caterina

    2016-01-14

    Gorlin-Goltz (GS) syndrome is an autosomal dominant disease linked to a mutation in the PTCH gene. Major criteria include the onset of multiple basal cell carcinoma (BCC), keratocystic odontogenic tumours in the jaws and bifid ribs. Dermoscopy and reflectance confocal microscopy represent imaging tools that are able to increase the diagnostic accuracy of skin cancer in a totally noninvasive manner, without performing punch biopsies. Here we present a case of a young woman in whom the combined approach of dermoscopy and RCM led to the identification of multiple small inconspicuous lesions as BCC and thus to the diagnosis of GS syndrome.

  5. Bidirectional Reflectance of a Macroscopically Flat, High-Albedo Particulate Surface: An Efficient Radiative Transfer Solution and Applications to Regoliths

    NASA Technical Reports Server (NTRS)

    Mishchenko, Michael I.; Zakharova, Nadia T.

    1999-01-01

    Many remote sensing applications rely on accurate knowledge of the bidirectional reflection function (BRF) of surfaces composed of discrete, randomly positioned scattering particles. Theoretical computations of BRFs for plane-parallel particulate layers are usually reduced to solving the radiative transfer equation (RTE) using one of existing exact or approximate techniques. Since semi-empirical approximate approaches are notorious for their low accuracy, violation of the energy conservation law, and ability to produce unphysical results, the use of numerically exact solutions of RTE has gained justified popularity. For example, the computation of BRFs for macroscopically flat particulate surfaces in many geophysical publications is based on the adding-doubling (AD) and discrete ordinate (DO) methods. A further saving of computer resources can be achieved by using a more efficient technique to solve the plane-parallel RTE than the AD and DO methods. Since many natural particulate surfaces can be well represented by the model of an optically semi-infinite, homogeneous scattering layer, one can find the BRF directly by solving the Ambartsumian's nonlinear integral equation using a simple iterative technique. In this way, the computation of the internal radiation field is avoided and the computer code becomes highly efficient and very accurate and compact. Furthermore, the BRF thus obtained fully obeys the fundamental physical laws of energy conservation and reciprocity. In this paper, we discuss numerical aspects and the computer implementation of this technique, examine the applicability of the Henyey-Greenstein phase function and the sigma-Eddington approximation in BRF and flux calculations, and describe sample applications demonstrating the potential effect of particle shape on the bidirectional reflectance of flat regolith surfaces. Although the effects of packing density and coherent backscattering are currently neglected, they can also be incorporated. The

  6. Divided-aperture differential confocal fast-imaging microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Qiu, Lirong; Zhao, Xiangye; Zhao, Weiqian

    2017-03-01

    A new method, laser divided-aperture differential confocal microscopy (DDCM), is proposed to achieve high-resolution 3D imaging of microstructures of large-scale sample surfaces. This method uses a divided-aperture confocal structure to significantly improve the axial resolution of confocal microscopy and keep a long working distance simultaneously; uses two radically offset point detectors to achieve differential detection to further improve the axial response sensitivity and realize fast imaging of a large-scale sample surface with a big axial scan-step interval. Theoretical analyses and experimental results show that the DDCM can reach an axial resolution of 5 nm with a 3.1 mm working distance with a 3 times imaging speed of a confocal system with the same resolution.

  7. WAVELENGTH AND ALIGNMENT TESTS FOR CONFOCAL SPECTRAL IMAGING SYSTEMS

    EPA Science Inventory

    Confocal spectral imaging (CSI) microscope systems now on the market delineate multiple fluorescent proteins, labels, or dyes within biological specimens by performing spectral characterizations. However, we find that some CSI present inconsistent spectral profiles of reference s...

  8. Anti-confocal assessment of middle ear inflammation

    PubMed Central

    Jung, David S.; Crowe, John A.; Birchall, John P.; Somekh, Michael G.; See, Chung W.

    2016-01-01

    To improve the diagnostic prediction of recurrence of otitis media with effusion after surgery, an anti-confocal system combined with spectroscopic measurements is proposed to reject unwanted signals from the eardrum and assess the blood content. The anti-confocal system was experimentally evaluated on both optical middle ear phantom and human skin. Results showed effective rejection of signals from the eardrum using a central stop replacing the confocal pinhole, while still detecting signals from the middle ear mucosa. The system is sensitive to changes in blood content, but scattering and absorption characteristics of the eardrum can distort the measurement. Confocal detection of eardrum properties was shown to be a promising approach to correct measurements. PMID:28101414

  9. CALIBRATION AND VALIDATION OF CONFOCAL SPECTRAL IMAGING SYSTEMS

    EPA Science Inventory

    Confocal spectral imaging (CSI) microscope systems now on the market can perform spectral characterization of biological specimens containing fluorescent proteins, labels or dyes. Some CSI have been found to present inconsistent spectral characterizations within a particular syst...

  10. CONFOCAL LASER SCANNING MICROSCOPY OF APOPTOSIS IN WHOLE MOUSE OVARIES

    EPA Science Inventory

    Confocal Laser Scanning Microscopy of Apoptosis in Whole Mouse Ovaries. Robert M. Zucker Susan C. Jeffay and Sally D. Perreault Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle...

  11. Development of optical fiber Bragg grating force-reflection sensor system of medical application for safe minimally invasive robotic surgery

    NASA Astrophysics Data System (ADS)

    Song, Hoseok; Kim, Kiyoung; Lee, Jungju

    2011-07-01

    Force feedback plays a very important role in medical surgery. In minimally invasive surgery (MIS), however, the very long and stiff bars of surgical instruments greatly diminish force feedback for the surgeon. In the case of minimally invasive robotic surgery (MIRS), force feedback is totally eliminated. Previous researchers have reported that the absence of force feedback increased the average force magnitude applied to the tissue by at least 50%, and increased the peak force magnitude by at least a factor of two. Therefore, it is very important to provide force information in MIRS. Recently, many sensors are being developed for MIS and MIRS, but some obstacles to their application in actual medical surgery must be surmounted. The most critical problems are size limit and sterilizability. Optical fiber sensors are among the most suitable sensors for the surgical environment. The optical fiber Bragg grating (FBG) sensor, in particular, offers an important additional advantage over other optical fiber sensors in that it is not influenced by the intensity of the light source. In this paper, we present the initial results of a study on the application of a FBG sensor to measure reflected forces in MIRS environments and suggest the possibility of successful application to MIRS systems.

  12. Probing chirality of a lipid tubular by confocal Raman microscopy.

    PubMed

    Kiang-ia, Jarinee; Hailong, Hu; Bin, Yan; Jantippana, Yuwathida; Pantu, Piboon; Limtrakul, Jumras; Chattham, Nattaporn; Zexiang, Shen; Ting, Yu

    2010-11-01

    The chiral phospholipids 1,2-bis-(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9 PC) can self assemble into lipid nanotubules. This hollow cylindrical supramolecular structure shows promise in a number of biotechnological applications. The mechanism of lipid tubule formation was initiated by assembling of lipid bilayer sheets from amphiphilic solution. Upon cooling, small ribbons were detached from the sheets and rolled up into helical tubules. The lipid tubules obtained were 0.6-0.8 microm in diameter and approximately 50 microm in length. Raman spectra of individual polymerized lipid tubules were measured by focused laser excitation of 532 nm leading to intense and reproducible Raman spectra. The chirality of lipid tubules was investigated by atomic force microscopy (AFM) and confocal Raman microscopy. We report the Raman mapping images revealing helical tubular profiles of C=C stretching and C[triple bond]C stretching of lipid tubules. Circular dichroism property of lipid tubules has also been probed with a 532 nm laser.

  13. Confocal fluorescence microscopy for detection of cervical preneoplastic lesions

    NASA Astrophysics Data System (ADS)

    Sheikhzadeh, Fahime; Ward, Rabab K.; Carraro, Anita; Chen, Zhaoyang; van Niekerk, Dirk; MacAulay, Calum; Follen, Michele; Lane, Pierre; Guillaud, Martial

    2015-03-01

    We examined and established the potential of ex-vivo confocal fluorescence microscopy for differentiating between normal cervical tissue, low grade Cervical Intraepithelial Neoplasia (CIN1), and high grade CIN (CIN2 and CIN3). Our objectives were to i) use Quantitative Tissue Phenotype (QTP) analysis to quantify nuclear and cellular morphology and tissue architecture in confocal microscopic images of fresh cervical biopsies and ii) determine the accuracy of high grade CIN detection via confocal microscopy. Cervical biopsy specimens of colposcopically normal and abnormal tissues obtained from 15 patients were evaluated by confocal fluorescence microscopy. Confocal images were analyzed and about 200 morphological and architectural features were calculated at the nuclear, cellular, and tissue level. For the purpose of this study, we used four features to delineate disease grade including nuclear size, cell density, estimated nuclear-cytoplasmic (ENC) ratio, and the average of three nearest Delaunay neighbors distance (3NDND). Our preliminary results showed ENC ratio and 3NDND correlated well with histopathological diagnosis. The Spearman correlation coefficient between each of these two features and the histopathological diagnosis was higher than the correlation coefficient between colposcopic appearance and histopathological diagnosis. Sensitivity and specificity of ENC ratio for detecting high grade CIN were both equal to 100%. QTP analysis of fluorescence confocal images shows the potential to discriminate high grade CIN from low grade CIN and normal tissues. This approach could be used to help clinicians identify HGSILs in clinical settings.

  14. Confocal laser endomicroscopy and immunoendoscopy for real-time assessment of vascularization in gastrointestinal malignancies.

    PubMed

    Gheonea, Dan Ionuţ; Cârţână, Tatiana; Ciurea, Tudorel; Popescu, Carmen; Bădărău, Anca; Săftoiu, Adrian

    2011-01-07

    Gastrointestinal cancers represent a major cause of morbidity and mortality, with incomplete response to chemotherapy in the advanced stages and poor prognosis. Angiogenesis plays a crucial part in tumor growth and metastasis, with most gastrointestinal cancers depending strictly on the development of a new and devoted capillary network. Confocal laser endomicroscopy is a new technology which allows in vivo microscopic analysis of the gastrointestinal mucosa and its microvascularization during ongoing endoscopy by using topically or systemically administered contrast agents. Targeting markers of angiogenesis in association with confocal laser endomicroscopic examination (immunoendoscopy), as a future challenge, will add functional analysis to the morphological aspect of the neoplastic process. This review describes previous experience in endomicroscopic examination of the upper and lower digestive tract with emphasis on vascularization, resulting in a broad spectrum of potential clinical applications, and also preclinical research that could be translated to human studies.

  15. Dental pulp stem cells (DPSCs) differentiation study by confocal Raman microscopy

    NASA Astrophysics Data System (ADS)

    Salehi, H.; Collart-Dutilleul, P.-Y.; Gergely, C.; Cuisinier, F. J. G.

    2014-03-01

    Regenerative medicine brings a huge application for Mesenchymal stem cells such as Dental Pulp Stem Cells (DPSCs). Confocal Raman microscopy, a non-invasive, label free , real time and high spatial resolution imaging technique is used to study osteogenic differentiation of DPSCs. Integrated Raman intensities in the 2800-3000 cm-1 region (C-H stretching) and 960 cm-1 peak (phosphate PO4 3-) were collected. In Dental Pulp Stem Cells 21st day differentiated in buffer solution, phosphate peaks ν1 PO4 3- (first vibrational mode) at 960cm-1 and ν2 PO4 3- at 430cm-1 and ν4 PO4 3- at 585cm-1 are obviously present. Confocal Raman microscopy enables the detection of cell differentiation and it can be used to investigate clinical stem cell research.

  16. Confocal Raman microscopy to monitor extracellular matrix during dental pulp stem cells differentiation

    NASA Astrophysics Data System (ADS)

    Salehi, Hamideh; Collart-Dutilleul, Pierre-Yves; Gergely, Csilla; Cuisinier, Frédéric J. G.

    2015-07-01

    Regenerative medicine brings promising applications for mesenchymal stem cells, such as dental pulp stem cells (DPSCs). Confocal Raman microscopy, a noninvasive technique, is used to study osteogenic differentiation of DPSCs. Integrated Raman intensities in the 2800 to 3000 cm-1 region (C-H stretching) and the 960 cm-1 peak (ν1 PO43-) were collected (to image cells and phosphate, respectively), and the ratio of two peaks 1660 over 1690 cm-1 (amide I bands) to measure the collagen cross-linking has been calculated. Raman spectra of DPSCs after 21 days differentiation reveal several phosphate peaks: ν1 (first stretching mode) at 960 cm-1, ν2 at 430 cm-1, and ν4 at 585 cm-1 and collagen cross-linking can also be calculated. Confocal Raman microscopy enables monitoring osteogenic differentiation in vitro and can be a credible tool for clinical stem cell based research.

  17. Laser ablation of basal cell carcinomas guided by confocal microscopy

    NASA Astrophysics Data System (ADS)

    Sierra, Heidy; Cordova, Miguel; Nehal, Kishwer; Rossi, Anthony; Chen, Chih-Shan Jason; Rajadhyaksha, Milind

    2016-02-01

    Laser ablation offers precise and fast removal of superficial and early nodular types of basal cell carcinomas (BCCs). Nevertheless, the lack of histological confirmation has been a limitation. Reflectance confocal microscopy (RCM) imaging combined with a contrast agent can offer cellular-level histology-like feedback to detect the presence (or absence) of residual BCC directly on the patient. We conducted an ex vivo bench-top study to provide a set of effective ablation parameters (fluence, number of passes) to remove superficial BCCs while also controlling thermal coagulation post-ablation to allow uptake of contrast agent. The results for an Er:YAG laser (2.9 um and pulse duration 250us) show that with 6 passes of 25 J/cm2, thermal coagulation can be effectively controlled, to allow both the uptake of acetic acid (contrast agent) and detection of residual (or absence) BCCs. Confirmation was provided with histological examination. An initial in vivo study on 35 patients shows that the uptake of contrast agent aluminum chloride) and imaging quality is similar to that observed in the ex vivo study. The detection of the presence of residual tumor or complete clearance was confirmed in 10 wounds with (additional) histology and in 25 lesions with follow-up imaging. Our results indicate that resolution is sufficient but further development and use of appropriate contrast agent are necessary to improve sensitivity and specificity. Advances in RCM technology for imaging of lateral and deep margins directly on the patient may provide less invasive, faster and less expensive image-guided approaches for treatment of BCCs.

  18. Application of Reflectance Transformation Imaging Technique to Improve Automated Edge Detection in a Fossilized Oyster Reef

    NASA Astrophysics Data System (ADS)

    Djuricic, Ana; Puttonen, Eetu; Harzhauser, Mathias; Dorninger, Peter; Székely, Balázs; Mandic, Oleg; Nothegger, Clemens; Molnár, Gábor; Pfeifer, Norbert

    2016-04-01

    The world's largest fossilized oyster reef is located in Stetten, Lower Austria excavated during field campaigns of the Natural History Museum Vienna between 2005 and 2008. It is studied in paleontology to learn about change in climate from past events. In order to support this study, a laser scanning and photogrammetric campaign was organized in 2014 for 3D documentation of the large and complex site. The 3D point clouds and high resolution images from this field campaign are visualized by photogrammetric methods in form of digital surface models (DSM, 1 mm resolution) and orthophoto (0.5 mm resolution) to help paleontological interpretation of data. Due to size of the reef, automated analysis techniques are needed to interpret all digital data obtained from the field. One of the key components in successful automation is detection of oyster shell edges. We have tested Reflectance Transformation Imaging (RTI) to visualize the reef data sets for end-users through a cultural heritage viewing interface (RTIViewer). The implementation includes a Lambert shading method to visualize DSMs derived from terrestrial laser scanning using scientific software OPALS. In contrast to shaded RTI no devices consisting of a hardware system with LED lights, or a body to rotate the light source around the object are needed. The gray value for a given shaded pixel is related to the angle between light source and the normal at that position. Brighter values correspond to the slope surfaces facing the light source. Increasing of zenith angle results in internal shading all over the reef surface. In total, oyster reef surface contains 81 DSMs with 3 m x 2 m each. Their surface was illuminated by moving the virtual sun every 30 degrees (12 azimuth angles from 20-350) and every 20 degrees (4 zenith angles from 20-80). This technique provides paleontologists an interactive approach to virtually inspect the oyster reef, and to interpret the shell surface by changing the light source direction

  19. Reflective Packaging

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The aluminized polymer film used in spacecraft as a radiation barrier to protect both astronauts and delicate instruments has led to a number of spinoff applications. Among them are aluminized shipping bags, food cart covers and medical bags. Radiant Technologies purchases component materials and assembles a barrier made of layers of aluminized foil. The packaging reflects outside heat away from the product inside the container. The company is developing new aluminized lines, express mailers, large shipping bags, gel packs and insulated panels for the building industry.

  20. Application of Hapke photometric model to three geologic surfaces using PARABOLA bidirectional reflection data

    NASA Technical Reports Server (NTRS)

    Shepard, Michael K.; Arvidson, Raymond E.; Deering, Donald W.

    1991-01-01

    The Geologic Remote Sensing Field Experiment (GRSFE) was conducted in July and September of 1989 to collect data with both ground and airborne instrumentation. A major objective of GRSFE was to collect data which could be used to test radiative transfer models for the extraction of composition and textural surface properties from remotely acquired data. Reported here are the initial results from an application of the Hapke photometric model, using data from the Portable Apparatus for Remote Acquisition of Bidirectional Observations of Land and Atmosphere (PARABOLA), a ground based radiometer with three spectral channels. PARABOLA data was collected in the Lunar Crater Volcanic Field in Nevada, specifically from the region of Lunar Lake, a playa. The Hapke model was found to be inadequate for three relatively common geologic surfaces (a clay-rich, hard packed surface with decimeter sized mudcracks; a cobble site, similar to a playa site, but strewn with basaltic cobbles and pebbles; and a surface mantled basalt lava flow). The model is not at fault; rather, the complexity of most geologic surfaces is not accounted for in the initial assumptions.

  1. Correction of terrestrial LiDAR intensity channel using Oren-Nayar reflectance model: An application to lithological differentiation

    NASA Astrophysics Data System (ADS)

    Carrea, Dario; Abellan, Antonio; Humair, Florian; Matasci, Battista; Derron, Marc-Henri; Jaboyedoff, Michel

    2016-03-01

    Ground-based LiDAR has been traditionally used for surveying purposes via 3D point clouds. In addition to XYZ coordinates, an intensity value is also recorded by LiDAR devices. The intensity of the backscattered signal can be a significant source of information for various applications in geosciences. Previous attempts to account for the scattering of the laser signal are usually modelled using a perfect diffuse reflection. Nevertheless, experience on natural outcrops shows that rock surfaces do not behave as perfect diffuse reflectors. The geometry (or relief) of the scanned surfaces plays a major role in the recorded intensity values. Our study proposes a new terrestrial LiDAR intensity correction, which takes into consideration the range, the incidence angle and the geometry of the scanned surfaces. The proposed correction equation combines the classical radar equation for LiDAR with the bidirectional reflectance distribution function of the Oren-Nayar model. It is based on the idea that the surface geometry can be modelled by a relief of multiple micro-facets. This model is constrained by only one tuning parameter: the standard deviation of the slope angle distribution (σslope) of micro-facets. Firstly, a series of tests have been carried out in laboratory conditions on a 2 m2 board covered by black/white matte paper (perfect diffuse reflector) and scanned at different ranges and incidence angles. Secondly, other tests were carried out on rock blocks of different lithologies and surface conditions. Those tests demonstrated that the non-perfect diffuse reflectance of rock surfaces can be practically handled by the proposed correction method. Finally, the intensity correction method was applied to a real case study, with two scans of the carbonate rock outcrop of the Dents-du-Midi (Swiss Alps), to improve the lithological identification for geological mapping purposes. After correction, the intensity values are proportional to the intrinsic material reflectance

  2. Three-dimensional imaging and image analysis of hippocampal neurons: confocal and digitally enhanced wide field microscopy.

    PubMed

    Turner, J N; Szarowski, D H; Turner, T J; Ancin, H; Lin, W C; Roysam, B; Holmes, T J

    1994-11-01

    The microscopy of biological specimens has traditionally been a two-dimensional imaging method for analyzing what are in reality three-dimensional (3-D) objects. This has been a major limitation of the application of one of science's most widely used tools. Nowhere has this limitation been more acute than in neurobiology, which is dominated by the necessity of understanding both large- and small-scale 3-D anatomy. Fortunately, recent advances in optical instrumentation and computational methods have provided the means for retrieving the third dimension, making full 3-D microscopic imaging possible. Optical designs have concentrated on the confocal imaging mode while computational methods have made 3-D imaging possible with wide field microscopes using deconvolution methods. This work presents a brief review of these methods, especially as applied to neurobiology, and data using both approaches. Specimens several hundred micrometers thick can be sampled allowing essentially intact neurons to be imaged. These neurons or selected components can be contrasted with either fluorescent, absorption, or reflection stains. Image analysis in 3-D is as important as visualization in 3-D. Automated methods of cell counting and analysis by nuclear detection as well as tracing of individual neurons are presented.

  3. Wideband energy reflectance measurements: effects of negative middle ear pressure and application of a pressure compensation procedure.

    PubMed

    Shaver, Mark D; Sun, Xiao-Ming

    2013-07-01

    The wideband energy reflectance (ER) technique has become popular as a tool for evaluating middle ear function. Negative middle ear pressure (MEP) is a prevalent form of middle ear dysfunction, which may impact application of ER measurements in differential diagnosis. A negative MEP may be countervailed by application of an equivalent negative ear canal pressure. The present study examined ER in the same ears under normal and experimentally induced negative MEP conditions. Thirty-five subjects produced at least one negative MEP each (-40 to -225 daPa). Negative MEP significantly altered ER in a frequency-specific manner that varied with MEP magnitude. ER increased for low- to mid-frequencies with the largest change (~0.20 to 0.40) occurring between 1 and 1.5 kHz. ER decreased for frequencies above 3 kHz with the largest change (~-0.10 to -0.25) observed between 4.5 and 5.5 kHz. Magnitude of changes increased as MEP became more negative, as did the frequencies at which maximum changes occurred, and the frequency at which enhancement transitioned to reduction. Ear canal pressure compensation restored ER to near baseline values. This suggests that the compensation procedure adequately mitigates the effects of negative MEP on ER. Theoretical issues and clinical implications are discussed.

  4. Internal features of graphite in cast irons. Confocal microscopy: useful tool for graphite growth imaging.

    PubMed

    Llorca-Isern, N; Tartera, J; Espanol, M; Marsal, M; Bertran, G; Castel, S

    2002-01-01

    Spherulitic crystallisation is a mode of growth of crystals from the melt. Considerable attention has been given to spheroidal graphite formation, providing detailed information about the internal microstructure of the spherulites in spheroidal (SG irons) and compacted graphite irons (CG irons) (Stefanescu, D., 1990. Cast Irons. ASM Handbook, 10th ed., vol. 1). Nevertheless, the mechanisms responsible for this mode of crystallisation are not fully understood. This study deals with the inoculation mechanisms, with particular emphasis on the study of the inclusions for the heterogeneous nucleation of graphite. It is shown that the graphite nuclei are sulfide products of the nodularizing treatment. It has been observed that when rare-earth treatment is applied, the central nucleus consists of a core and an envelope from which the graphite grows. Confocal Scanning Laser Microscopy (CSLM), in reflection mode, was used to study the internal features of the spheroidal graphite growth. Confocal reflection imaging, which has a capacity for optical sectioning of the sample, provides high-resolution images of surface and subsurface regions of interest contained within a semi-transparent sample. Furthermore, three-dimensional reconstruction of these optical sections can provide insight into the mechanism of graphite growth mechanism interpretation. With CSLM the radial growth of graphite was seen. Other techniques, such as TEM, SEM-EDS, WDS, AES and SAM were also used to corroborate the results.

  5. High resolution fundus imaging by confocal scanning laser ophthalmoscopy in the mouse.

    PubMed

    Paques, Michel; Simonutti, Manuel; Roux, Michel J; Picaud, Serge; Levavasseur, Etienne; Bellman, Caren; Sahel, José-Alain

    2006-04-01

    We evaluated fundus imaging using a modified confocal scanning laser ophthalmoscope (cSLO) in mice. Examinations were performed in conscious, untrained mice. The largest field of view measured 1,520 x 1,520 mu, with a significant interindividual variability, itself correlated to biometric variability. The composite field of view extended up to the ora serrata. The reflectance imaging associated light reflection from nerve fiber bundles and vessel walls, and absorption by hemoglobin and melanin. Light absorption by the pigment epithelium indeed increased the contrast of the nerve fiber layer, but impaired viewing of the choroid. Due to the confocal mode, fluorescence angiograms with clear separation of retinal and choroidal fluorescence could be obtained even in albino mice. Micrometric-scale transverse resolution and several planes of optical sectioning within the retina were obtained. This permitted for instance tridimensional, subcellular viewing of gfp-expressing retinal microglial cells in CX(3)CR1 mice. We concluded that cSLO is a promising tool for noninvasive, multimodal intravital microscopy of the fundus in the mouse.

  6. Reflection Coefficients.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1994-01-01

    Discusses and provides an example of reflectivity approximation to determine whether reflection will occur. Provides a method to show thin-film interference on a projection screen. Also applies the reflectivity concepts to electromagnetic wave systems. (MVL)

  7. Confocal soft X-ray scanning transmission microscopy: setup, alignment procedure and limitations

    PubMed Central

    Späth, Andreas; Raabe, Jörg; Fink, Rainer H.

    2015-01-01

    Zone-plate-based scanning transmission soft X-ray microspectroscopy (STXM) is a well established technique for high-contrast imaging of sufficiently transparent specimens (e.g. ultrathin biological tissues, polymer materials, archaeometric specimens or magnetic thin films) with spatial resolutions in the regime of 20 nm and high spectroscopic or chemical sensitivity. However, due to the relatively large depth of focus of zone plates, the resolution of STXM along the optical axis so far stays unambiguously behind for thicker X-ray transparent specimens. This challenge can be addressed by the implementation of a second zone plate in the detection pathway of the beam, resulting in a confocal arrangement. Within this paper a first proof-of-principle study for a confocal STXM (cSTXM) and an elaborate alignment procedure in transmission and fluorescence geometry are presented. Based on first confocal soft X-ray micrographs of well known specimens, the advantage and limitation of cSTXM as well as further development potentials for future applications are discussed. PMID:25537596

  8. Opto-photo-thermo-elastic displacement detection using coherent confocal microscope

    NASA Astrophysics Data System (ADS)

    Eliyahu, Igal; DiMarzio, Charles A.

    2009-02-01

    Photothermal spectroscopy is a powerful tool to investigate the optical absorption and thermal characteristics of a sample. The photo-thermal effect, that is the basis for photothermal spectroscopy, is the conversion of optical energy into heat. Photothermal spectroscopy is implemented in a variety of methods. Biomedical imaging applications commonly implement the Photo-Thermo-Acoustic (PTA) method, that is based on measuring the acoustic pressure wave that propagates due to the photothermal effect, caused by absorption of energy from a heating laser. This research demonstrates photothermal elastic displacement measurement using a coherent confocal microscope, as a first step towered pothothermal spectroscopy. The high accuracy of the interferometer, that is the heart of the coherent confocal microscope, in detecting small changes in position makes it intrinsically adequate to measure the thermoelastic expansion of the sample that results from the photothermal process. In this research Polyvinyl-Chloride Plastisol (PVCP) samples, constructed with different absorption coefficients, were tested using different heating light fluences. The results are compared against an approximate theoretical model and are found to be in good agreement. The Opto-Photo-Thermo-Elastic (Optical detection of elastic displacement changes due to the phototheraml process) technique is demonstrated in this research as a first step toward extending the capability of confocal microscopes to image deeper into tissues than is presently possible, and to detect new modes of contrast.

  9. Super-resolution mapping of glutamate receptors in C. elegans by confocal correlated PALM

    PubMed Central

    Vangindertael, Jeroen; Beets, Isabel; Rocha, Susana; Dedecker, Peter; Schoofs, Liliane; Vanhoorelbeeke, Karen; Hofkens, Johan; Mizuno, Hideaki

    2015-01-01

    Photoactivated localization microscopy (PALM) is a super-resolution imaging technique based on the detection and subsequent localization of single fluorescent molecules. PALM is therefore a powerful tool in resolving structures and putative interactions of biomolecules at the ultimate analytical detection limit. However, its limited imaging depth restricts PALM mostly to in vitro applications. Considering the additional need for anatomical context when imaging a multicellular organism, these limitations render the use of PALM in whole animals difficult. Here we integrated PALM with confocal microscopy for correlated imaging of the C. elegans nervous system, a technique we termed confocal correlated PALM (ccPALM). The neurons, lying below several tissue layers, could be visualized up to 10 μm deep inside the animal. By ccPALM, we visualized ionotropic glutamate receptor distributions in C. elegans with an accuracy of 20 nm, revealing super-resolution structure of receptor clusters that we mapped onto annotated neurons in the animal. Pivotal to our results was the TIRF-independent detection of single molecules, achieved by genetic regulation of labeled receptor expression and localization to effectively reduce the background fluorescence. By correlating PALM with confocal microscopy, this platform enables dissecting biological structures with single molecule resolution in the physiologically relevant context of whole animals. PMID:26323790

  10. Fibre optic confocal imaging (FOCI) for subsurface microscopy of the colon in vivo.

    PubMed Central

    Delaney, P M; King, R G; Lambert, J R; Harris, M R

    1994-01-01

    Fibre optic confocal imaging (FOCI) is a new type of microscopy which has been recently developed (Delaney et al. 1993). In contrast to conventional light microscopy, FOCI and other confocal techniques allow clear imaging of subsurface structures within translucent objects. However, unlike conventional confocal microscopes which are bulky (because of a need for accurate alignment of large components) FOCI allows the imaging end to be miniaturised and relatively mobile. FOCI is thus particularly suited for clear subsurface imaging of structures within living animals or subjects. The aim of the present study was to assess the suitability of using FOCI for imaging of subsurface structures within the colon, both in vitro (human and rat biopsies) and in vivo (in rats). Images were obtained in fluorescence mode (excitation 488 nm, detection above 515 nm) following topical application of fluorescein. By this technique the glandular structure of the colon was imaged. FOCI is thus suitable for subsurface imaging of the colon in vivo. Images Fig. 2 Fig. 3 PMID:8157487

  11. Digital adaptive optics line-scanning confocal imaging system.

    PubMed

    Liu, Changgeng; Kim, Myung K

    2015-01-01

    A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea.

  12. Digital adaptive optics line-scanning confocal imaging system

    PubMed Central

    Liu, Changgeng; Kim, Myung K.

    2015-01-01

    Abstract. A digital adaptive optics line-scanning confocal imaging (DAOLCI) system is proposed by applying digital holographic adaptive optics to a digital form of line-scanning confocal imaging system. In DAOLCI, each line scan is recorded by a digital hologram, which allows access to the complex optical field from one slice of the sample through digital holography. This complex optical field contains both the information of one slice of the sample and the optical aberration of the system, thus allowing us to compensate for the effect of the optical aberration, which can be sensed by a complex guide star hologram. After numerical aberration compensation, the corrected optical fields of a sequence of line scans are stitched into the final corrected confocal image. In DAOLCI, a numerical slit is applied to realize the confocality at the sensor end. The width of this slit can be adjusted to control the image contrast and speckle noise for scattering samples. DAOLCI dispenses with the hardware pieces, such as Shack–Hartmann wavefront sensor and deformable mirror, and the closed-loop feedbacks adopted in the conventional adaptive optics confocal imaging system, thus reducing the optomechanical complexity and cost. Numerical simulations and proof-of-principle experiments are presented that demonstrate the feasibility of this idea. PMID:26140334

  13. Automated identification of neurons in 3D confocal datasets from zebrafish brainstem

    PubMed Central

    KAMALI, M.; DAY, L. J.; BROOKS, D. H.; ZHOU, X.; O’MALLEY, D. M.

    2009-01-01

    Summary Many kinds of neuroscience data are being acquired regarding the dynamic behaviour and phenotypic diversity of nerve cells. But as the size, complexity and numbers of 3D neuroanatomical datasets grow ever larger, the need for automated detection and analysis of individual neurons takes on greater importance. We describe here a method that detects and identifies neurons within confocal image stacks acquired from the zebrafish brainstem. The first step is to create a template that incorporates the location of all known neurons within a population – in this case the population of reticulospinal cells. Once created, the template is used in conjunction with a sequence of algorithms to determine the 3D location and identity of all fluorescent neurons in each confocal dataset. After an image registration step, neurons are segmented within the confocal image stack and subsequently localized to specific locations within the brainstem template – in many instances identifying neurons as specific, individual reticulospinal cells. This image-processing sequence is fully automated except for the initial selection of three registration points on a maximum projection image. In analysing confocal image stacks that ranged considerably in image quality, we found that this method correctly identified on average ~80% of the neurons (if we assume that manual detection by experts constitutes ‘ground truth’). Because this identification can be generated approximately 100 times faster than manual identification, it offers a considerable time savings for the investigation of zebrafish reticulospinal neurons. In addition to its cell identification function, this protocol might also be integrated with stereological techniques to enhance quantification of neurons in larger databases. Our focus has been on zebrafish brainstem systems, but the methods described should be applicable to diverse neural architectures including retina, hippocampus and cerebral cortex. PMID:19196418

  14. Method and tool to reverse the charges in anti-reflection films used for solar cell applications

    DOEpatents

    Sharma, Vivek; Tracy, Clarence

    2017-01-31

    A method is provided for making a solar cell. The method includes providing a stack including a substrate, a barrier layer disposed on the substrate, and an anti-reflective layer disposed on the barrier layer, where the anti-reflective layer has charge centers. The method also includes generating a corona with a charging tool and contacting the anti-reflective layer with the corona thereby injecting charge into at least some of the charge centers in the anti-reflective layer. Ultra-violet illumination and temperature-based annealing may be used to modify the charge of the anti-reflective layer.

  15. Tri-modal confocal margin screening for the presence of residual squamous cell carcinoma in Mohs surgical excisions

    NASA Astrophysics Data System (ADS)

    Bar, Anna; Snavely, Nicholas; Chen, Nathaniel; Jacques, Steven; Gareau, Daniel S.

    2012-03-01

    Screening cancer in excision margins may be done with confocal microscopy to save time and cost over the gold standard histopathology (H&E). However, diagnostic accuracy requires sufficient contrast. Reflectance mode enables detection of large (>500um) nodular tumors. Enhanced nuclear contrast with acridine orange fluorescence mode additionally enables detection of tiny (<50um) basal cell carcinomas. Here, we present a novel combination of three modes to detect squamous cell carcinoma (SCC). Accurate screening of SCC requires eosin fluorescence, reflectance and acridine orange fluorescence to enable contrast for cytoplasm, collagen and nuclei respectively. Combining these signals replicates H&E for rapid clinical translation.

  16. Confocal photoacoustic microscopy using a single multifunctional lens.

    PubMed

    Xi, Lei; Song, Chaolong; Jiang, Huabei

    2014-06-01

    Photoacoustic microscopy (PAM) has remained one of the fastest developing biomedical imaging modalities in the past decade. The confocal strategy of optical illumination and acoustic detection is a way to boost the sensitivity of PAM. To achieve confocal PAM, current PAM systems utilize separate acoustic and optical converging devices, making the systems bulky and complicated. In this Letter, we demonstrate the use of a single-liquid lens to successfully achieve acoustic and optical confocal configuration for optical-resolution PAM (ORPAM). Using the lens with a numerical aperture of 0.43, we show that the resolution of the ORPAM system is 4.8 μm with a significantly improved sensitivity of acoustic detection. We also apply this compact ORPAM system to in vivo imaging of the vasculature of a rat ear.

  17. Simple high-speed confocal line-scanning microscope.

    PubMed

    Im, Kang-Bin; Han, Sumin; Park, Hwajoon; Kim, Dongsun; Kim, Beop-Min

    2005-06-27

    Using a line scan camera and an acousto-optic deflector (AOD), we constructed a high-speed confocal laser line-scanning microscope that can generate confocal images (512 x 512 pixels) with up to 191 frames/s without any mechanically moving parts. The line scanner consists of an AOD and a cylindrical lens, which creates a line focus sweeping over the sample. The measured resolutions in z (depth), x (perpendicular to line focus), and y (direction of line focus) directions are 3.3 mum, 0.7 mum and 0.9 mum, respectively, with a 50x objective lens. This confocal microscope may be useful for analyzing fast phenomena during biological and chemical interactions and for fast 3D image reconstruction.

  18. Applicability of near-infrared reflectance spectroscopy (NIRS) for determination of crude protein content in cowpea (Vigna unguiculata) leaves.

    PubMed

    Towett, Erick K; Alex, Merle; Shepherd, Keith D; Polreich, Severin; Aynekulu, Ermias; Maass, Brigitte L

    2013-01-01

    There is uncertainty on how generally applicable near-infrared reflectance spectroscopy (NIRS) calibrations are across genotypes and environments, and this study tests how well a single calibration performs across a wide range of conditions. We also address the optimization of NIRS to perform the analysis of crude protein (CP) content in a variety of cowpea accessions (n = 561) representing genotypic variation as well as grown in a wide range of environmental conditions in Tanzania and Uganda. The samples were submitted to NIRS analysis and a predictive calibration model developed. A modified partial least-squares regression with cross-validation was used to evaluate the models and identify possible spectral outliers. Calibration statistics for CP suggests that NIRS can predict this parameter in a wide range of cowpea leaves from different agro-ecological zones of eastern Africa with high accuracy (R (2)cal = 0.93; standard error of cross-validation = 0.74). NIRS analysis improved when a calibration set was developed from samples selected to represent the range of spectral variability. We conclude from the present results that this technique is a good alternative to chemical analysis for the determination of CP contents in leaf samples from cowpea in the African context, as one of the main advantages of NIRS is the large number of compounds that can be measured at once in the same sample, thus substantially reducing the cost per analysis. The current model is applicable in predicting the CP content of young cowpea leaves for human nutrition from different agro-ecological zones and genetic materials, as cowpea leaves are one of the popular vegetables in the region.

  19. Confocal microscopy reveals persisting stromal changes after myopic photorefractive keratectomy in zero haze corneas

    PubMed Central

    Bohnke, M.; Thaer, A.; Schipper, I.

    1998-01-01

    AIMS—Micromorphological examination of the central cornea in myopic patients 8-43 months after excimer laser photorefractive keratectomy (PRK), using the slit scanning confocal microscope.
METHODS—Patients were selected from a larger cohort of individuals on the basis of full corneal clarity (haze grading 0 to +1; mean 0.3) and their willingness to participate in the study. 15 eyes of 10 patients with myopic PRK (−4 to −11 D; mean 6.7) and an uneventful postoperative interval of 8-43 months (mean 26) were examined. Contact lenses had been worn by eight of the 10 patients for 4-11 years (mean 6.7) before surgery. Controls included the five untreated fellow eyes of PRK patients, 10 healthy, age matched volunteers without a history of ocular inflammation or contact lens wear, and 20 patients who had worn rigid gas permeable (n=10) or soft contact lenses (n=10) for 2-11 years. Subjects were examined with a real time flying slit, scanning confocal microscope using ×25 and ×50 objectives.
RESULTS—In PRK treated patients and contact lens wearers, basal layer epithelial cells sporadically displayed enhanced reflectivity. The subepithelial nerve plexus was observed in all individuals, but was usually less well contrasted in the PRK group, owing to the presence of a very discrete layer of subepithelial scar tissue, which patchily enhanced background reflectivity. Within all layers of the stroma, two distinct types of abnormal reflective bodies were observed in all PRK treated eyes, but in none of the controls. One had the appearance of long (>= 50 µm), slender (2-8 µm in diameter) dimly reflective rods, which sometimes contained bright, punctate, crystal-like inclusions, arranged linearly and at irregular intervals. The other was shorter (<25 µm), more slender in form (<1 µm in diameter), and highly reflective; these so called needles were composed of crystal-like granules in linear array, with an individual appearance similar to the bright

  20. Application of Fresnel diffraction from a 2D array of reflective disks in optical profilometry of a flat surface

    NASA Astrophysics Data System (ADS)

    Darudi, Ahmad; Asgari, Pegah; Pourvais, Yousef

    2015-05-01

    Optical methods of three-dimensional profilometry have been of growing interest in both industrial and scientific applications. These techniques provide absolutely non-destructive measurement due to their non-contact nature and maintain their high precision in a large field of view. Most of these techniques however, are based on interferometry which happens to be considerably sensitive to environmental noises such as turbulence and vibration. We have used the phenomena of Fresnel diffraction from phase-steps instead of interferometry to maintain a higher precision and reduce sensitivity to environmental noises. This phenomena has been recently introduced as a method for precise measurement of wavelength, thickness and refractive index. A 2D array of reflective disks are placed above the test surface to provide the required phase-steps. In this paper, theoretical principles of Fresnel diffraction from phase-steps are discussed and the experimental results of testing an optical flat surface are presented. A flat mirror surface has been tested as an optical test surface and is been profiled. The results show that the method is precise and is not sensitive to environmental noises such as vibration and turbulence. Furthermore, the method seems to be a powerful means for testing of curved surfaces, too.

  1. A Pico Projector Source for Confocal Fluorescence and Ophthalmic Imaging.

    PubMed

    Muller, Matthew S

    2012-09-02

    A Pico digital light projector has been implemented as an integrated illumination source and spatial light modulator for confocal imaging. The target is illuminated with a series of rapidly projected lines or points to simulate scanning. Light returning from the target is imaged onto a 2D rolling shutter CMOS sensor. By controlling the spatio-temporal relationship between the rolling shutter and illumination pattern, light returning from the target is spatially filtered. Confocal retinal, fluorescence, and Fourier-domain optical coherence tomography implementations of this novel imaging technique are presented.

  2. Confocal Raman imaging of crystalline an glassy materials

    SciTech Connect

    Bradley, N.L.; Morris, M.D.

    1995-12-31

    Spatial distribution of materials components can be measured by confocal Raman imaging. We describe a confocal line-imaging system in which the spectrograph entrance slit functions as a spatial filter. The instrument uses a scanning galvanometer mirror to generate uniform intensity line illumination. A flexure mount with better than 0.1 micrometer positioning accuracy moves the sample under the fixed optical system. The Raman scatter is collected and projected along the entrance slit of an axial transmissive spectrograph. A CCD collects spatially resolved spectra.

  3. Generalized model for incoherent detection in confocal optical microscopy.

    PubMed

    Hammoum, Rachid; Hamady, Sidi Ould Saad; Fontana, Marc D

    2010-06-01

    We develop a generalized model in order to calculate the point spread functions in both the focal and the detection planes for the electric field strengths. In these calculations, based on the generalized Jones matrices, we introduce all of the interdependent parameters that could influence the spatial resolution of a confocal optical microscope. Our proposed model is more nearly complete, since we make no approximations of the scattered electric fields. These results can be successfully applied to standard confocal optical techniques to get a better understanding for more quantitative interpretations of the probe.

  4. A Pico Projector Source for Confocal Fluorescence and Ophthalmic Imaging

    PubMed Central

    Muller, Matthew S.

    2013-01-01

    A Pico digital light projector has been implemented as an integrated illumination source and spatial light modulator for confocal imaging. The target is illuminated with a series of rapidly projected lines or points to simulate scanning. Light returning from the target is imaged onto a 2D rolling shutter CMOS sensor. By controlling the spatio-temporal relationship between the rolling shutter and illumination pattern, light returning from the target is spatially filtered. Confocal retinal, fluorescence, and Fourier-domain optical coherence tomography implementations of this novel imaging technique are presented. PMID:24236223

  5. Note: development of high speed confocal 3D profilometer.

    PubMed

    Ang, Kar Tien; Fang, Zhong Ping; Tay, Arthur

    2014-11-01

    A high-speed confocal 3D profilometer based on the chromatic confocal technology and spinning Nipkow disk technique has been developed and tested. It can measure a whole surface topography by taking only one image that requires less than 0.3 s. Surface height information is retrieved based on the ratios of red, green, and blue color information. A new vector projection technique has developed to enhance the vertical resolution of the measurement. The measurement accuracy of the prototype system has been verified via different test samples.

  6. Confocal mosaicing microscopy of human skin ex vivo: spectral analysis for digital staining to simulate histology-like appearance

    NASA Astrophysics Data System (ADS)

    Bini, Jason; Spain, James; Nehal, Kishwer; Hazelwood, Vikki; Dimarzio, Charles; Rajadhyaksha, Milind

    2011-07-01

    Confocal mosaicing microscopy enables rapid imaging of large areas of fresh tissue, without the processing that is necessary for conventional histology. Mosaicing may offer a means to perform rapid histology at the bedside. A possible barrier toward clinical acceptance is that the mosaics are based on a single mode of grayscale contrast and appear black and white, whereas histology is based on two stains (hematoxylin for nuclei, eosin for cellular cytoplasm and dermis) and appears purple and pink. Toward addressing this barrier, we report advances in digital staining: fluorescence mosaics that show only nuclei, are digitally stained purple and overlaid on reflectance mosaics, which show only cellular cytoplasm and dermis, and are digitally stained pink. With digital staining, the appearance of confocal mosaics mimics the appearance of histology. Using multispectral analysis and color matching functions, red, green, and blue (RGB) components of hematoxylin and eosin stains in tissue were determined. The resulting RGB components were then applied in a linear algorithm to transform fluorescence and reflectance contrast in confocal mosaics to the absorbance contrast seen in pathology. Optimization of staining with acridine orange showed improved quality of digitally stained mosaics, with good correlation to the corresponding histology.

  7. Analysis and design of nonlinear fiber Bragg gratings and their application for optical compression of reflected pulses.

    PubMed

    Rosenthal, Amir; Horowitz, Moshe

    2006-05-01

    We demonstrate a novel split-step solution for analyzing nonlinear fiber Bragg gratings. The solution is used for designing nonlinear fiber Bragg gratings with a low reflectivity. The structure of the grating is designed according to the profiles of the incident and reflected pulses. We demonstrate our method for nonlinear compression of a pulse reflected from a fiber Bragg grating. The method allows us to obtain compressed pulses with a very low wing intensity.

  8. Sensitivity and Specificity of Cardiac Tissue Discrimination Using Fiber-Optics Confocal Microscopy

    PubMed Central

    Huang, Chao; Sachse, Frank B.; Hitchcock, Robert W.; Kaza, Aditya K.

    2016-01-01

    Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy and extracellular fluorophores. Here, we applied this approach to investigate sensitivity and specificity of human and automated classification in discriminating images of atrial working myocardium and specialized tissue of the conduction system. Two-dimensional image sequences from atrial working myocardium and nodal tissue of isolated perfused rodent hearts were acquired using a fiber-optics confocal microscope (Leica FCM1000). We compared two methods for local application of extracellular fluorophores: topical via pipette and with a dye carrier. Eight blinded examiners evaluated 162 randomly selected images of atrial working myocardium (n = 81) and nodal tissue (n = 81). In addition, we evaluated the images using automated classification. Blinded examiners achieved a sensitivity and specificity of 99.2±0.3% and 98.0±0.7%, respectively, with the dye carrier method of dye application. Sensitivity and specificity was similar for dye application via a pipette (99.2±0.3% and 94.0±2.4%, respectively). Sensitivity and specificity for automated methods of tissue discrimination were similarly high. Human and automated classification achieved high sensitivity and specificity in discriminating atrial working myocardium and nodal tissue. We suggest that our findings facilitate clinical translation of fiber-optics confocal microscopy as an intraoperative imaging modality to reduce the incidence of conduction disturbances during surgical correction of congenital heart disease. PMID:26808149

  9. Sensitivity and Specificity of Cardiac Tissue Discrimination Using Fiber-Optics Confocal Microscopy.

    PubMed

    Huang, Chao; Sachse, Frank B; Hitchcock, Robert W; Kaza, Aditya K

    2016-01-01

    Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy and extracellular fluorophores. Here, we applied this approach to investigate sensitivity and specificity of human and automated classification in discriminating images of atrial working myocardium and specialized tissue of the conduction system. Two-dimensional image sequences from atrial working myocardium and nodal tissue of isolated perfused rodent hearts were acquired using a fiber-optics confocal microscope (Leica FCM1000). We compared two methods for local application of extracellular fluorophores: topical via pipette and with a dye carrier. Eight blinded examiners evaluated 162 randomly selected images of atrial working myocardium (n = 81) and nodal tissue (n = 81). In addition, we evaluated the images using automated classification. Blinded examiners achieved a sensitivity and specificity of 99.2 ± 0.3% and 98.0 ± 0.7%, respectively, with the dye carrier method of dye application. Sensitivity and specificity was similar for dye application via a pipette (99.2 ± 0.3% and 94.0 ± 2.4%, respectively). Sensitivity and specificity for automated methods of tissue discrimination were similarly high. Human and automated classification achieved high sensitivity and specificity in discriminating atrial working myocardium and nodal tissue. We suggest that our findings facilitate clinical translation of fiber-optics confocal microscopy as an intraoperative imaging modality to reduce the incidence of conduction disturbances during surgical correction of congenital heart disease.

  10. Reflection-contrast limit of fiber-optic image guides

    PubMed Central

    Lane, Pierre M.; MacAulay, Calum E.

    2009-01-01

    Fiber-optic image guides in confocal reflectance endomicroscopes introduce background backscatter that limits the achievable contrast in these devices. We show the dominant source of backscatter from the image guide is due to Rayleigh scattering at short wavelengths and terminal reflections of the fibers at long wavelengths. The effective Rayleigh scattering coefficient and the wavelength-independent reflectivity due terminal reflections are measured experimentally in a commercial image guide. The Rayleigh scattering component of backscatter can be accurately predicted using the fractional refractive-index difference and length of the fibers in the image guide. We also presented a simple model that can be used to predict signal-to-background ratio in a fiber-optic confocal reflectance endomicroscope for biologically relevant tissues and contrast agents that cover a wide range of reflectivity. PMID:20059266

  11. The Reflective Learning Continuum: Reflecting on Reflection

    ERIC Educational Resources Information Center

    Peltier, James W.; Hay, Amanda; Drago, William

    2005-01-01

    The importance of reflection to marketing educators is increasingly recognized. However, there is a lack of empirical research that considers reflection within the context of both the marketing and general business education literature. This article describes the use of an instrument that can be used to measure four identified levels of a…

  12. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR MEASUREMENTS, QUANTITATION AND SPECTROSCOPY

    EPA Science Inventory

    The confocal laser-scanning microscopy (CLSM) has enormous potential in many biological fields. The goal of a CLSM is to acquire and quantify fluorescence and in some instruments acquire spectral characterization of the emitted signal. The accuracy of these measurements demands t...

  13. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, Richard A.; Peck, Konan

    1992-01-01

    A fluorescent scanner for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier including a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from said volume to provide a display of the separated sample.

  14. Axial resolution of a chromatic dispersion confocal microscopy

    NASA Astrophysics Data System (ADS)

    Garzon Reyes, Johnson; Meneses, J.; Plata, Arturo; Tribillon, Gilbert M.; Gharbi, Tijani

    2004-10-01

    An analysis of the axial resolution of a chromatic dispersion confocal microscopy is presented. The system is based on the principle of focus multiplexing by wavelength encoding due to a phase Fresnel lens. The axial resolution is related with the measure of the FWHM value of every spectral response.

  15. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: SPECTROSCOPY AND FOUNDATIONS FOR QUANTITATION

    EPA Science Inventory

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The reliability of the CLSM to obtain specific measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. For man...

  16. Laser excited confocal microscope fluorescence scanner and method

    DOEpatents

    Mathies, R.A.; Peck, K.

    1992-02-25

    A fluorescent scanner is designed for scanning the fluorescence from a fluorescence labeled separated sample on a sample carrier. The scanner includes a confocal microscope for illuminating a predetermined volume of the sample carrier and/or receiving and processing fluorescence emissions from the volume to provide a display of the separated sample. 8 figs.

  17. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: QA TESTS, QUANTITATION AND SPECTROSCOPY

    EPA Science Inventory

    Confocal Microscopy System Performance: QA tests, Quantitation and Spectroscopy.

    Robert M. Zucker 1 and Jeremy M. Lerner 2,
    1Reproductive Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research Development, U.S. Environmen...

  18. In vivo confocal microscopy of the human cornea

    PubMed Central

    Jalbert, I; Stapleton, F; Papas, E; Sweeney, D F; Coroneo, M

    2003-01-01

    Aims: To describe the optics of in vivo confocal microscopy, its advantages over previous methods, and to summarise the literature that arose from its use for the observation of the human cornea. A critical review of the clinical usefulness of this new technology for the corneal examination is undertaken. Methods: Confocal microscopes obtain increased resolution by limiting the illumination and observation systems to a single point. Rapid scanning is used to reconstruct a full field of view and allows for “real time” viewing. Results: Coronal sections of the in situ epithelium, Bowman’s membrane, stroma, and endothelium can be visualised at a resolution of 1–2 μm. A backscattered light intensity curve allows objective measurements of sublayer thickness and corneal haze to be taken. In vivo confocal microscopy is therefore particularly useful in the areas of infective keratitis, corneal dystrophies, refractive surgery, and contact lens wear, where it aids in differential diagnosis and detection of subtle short and long term changes. Real time endothelial cell assessment can also be performed. Conclusion: Because of their ability to visualise living tissue at cellular levels, confocal microscopes have proved useful additions to the current clinical tools. PMID:12543757

  19. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: FOUNDATIONS FOR CALIBRATION, QUANTITATION AND SPECTROSCOPY

    EPA Science Inventory

    The confocal laser-scanning microscope (CLSM) has enormous potential in many biological fields. The goal of a CLSM is to acquire and quantify fluorescence and in some instruments acquire spectral characterization of emitted signals. The accuracy of these measurements demands that...

  20. Application of CO2 Snow Jet Cleaning in Conjunction with Laboratory Based Total Reflection X-Ray Fluorescence

    NASA Technical Reports Server (NTRS)

    Schmeling, M.; Burnett, D. S.; Allton, J. H.; Rodriquez, M.; Tripa, C. E.; Veryovkin, I. V.

    2013-01-01

    The Genesis mission was the first mission returning solar material to Earth since the Apollo program [1,2]. Unfortunately the return of the space craft on September 8, 2004 resulted in a crash landing, which shattered the samples into small fragments and exposed them to desert soil and other debris. Thus only small fragments of the original collectors are available, each having different degrees of surface contamination. Thorough surface cleaning is required to allow for subsequent analysis of solar wind material embedded within. An initial cleaning procedure was developed in coordination with Johnson Space Center which focused on removing larger sized particulates and a thin film organic contamination acquired during collection in space [3]. However, many of the samples have additional residues and more rigorous and/or innovative cleaning steps might be necessary. These cleaning steps must affect only the surface to avoid leaching and re-distribution of solar wind material from the bulk of the collectors. To aid in development and identification of the most appropriate cleaning procedures each sample has to be thoroughly inspected before and after each cleaning step. Laboratory based total reflection X-ray fluorescence (TXRF) spectrometry lends itself to this task as it is a non-destructive and surface sensitive analytical method permitting analysis of elements from aluminum onward present at and near the surface of a flat substrate [4]. The suitability of TXRF has been demonstrated for several Genesis solar wind samples before and after various cleaning methods including acid treatment, gas cluster ion beam, and CO2 snow jet [5 - 7]. The latter one is non-invasive and did show some promise on one sample [5]. To investigate the feasibility of CO2 snow jet cleaning further, several flown Genesis samples were selected to be characterized before and after CO2 snow application with sample 61052 being discussed below.

  1. Solar Confocal interferometers for Sub-Picometer-Resolution Spectral Filters

    NASA Technical Reports Server (NTRS)

    Gary, G. Allen; Pietraszewski, Chris; West, Edward A.; Dines. Terence C.

    2007-01-01

    The confocal Fabry-Perot interferometer allows sub-picometer spectral resolution of Fraunhofer line profiles. Such high spectral resolution is needed to keep pace with the higher spatial resolution of the new set of large-aperture solar telescopes. The line-of-sight spatial resolution derived for line profile inversions would then track the improvements of the transverse spatial scale provided by the larger apertures. In particular, profile inversion allows improved velocity and magnetic field gradients to be determined independent of multiple line analysis using different energy levels and ions. The confocal interferometer's unique properties allow a simultaneous increase in both etendue and spectral power. The higher throughput for the interferometer provides significant decrease in the aperture, which is important in spaceflight considerations. We have constructed and tested two confocal interferometers. A slow-response thermal-controlled interferometer provides a stable system for laboratory investigation, while a piezoelectric interferometer provides a rapid response for solar observations. In this paper we provide design parameters, show construction details, and report on the laboratory test for these interferometers. The field of view versus aperture for confocal interferometers is compared with other types of spectral imaging filters. We propose a multiple etalon system for observing with these units using existing planar interferometers as pre-filters. The radiometry for these tests established that high spectral resolution profiles can be obtained with imaging confocal interferometers. These sub-picometer spectral data of the photosphere in both the visible and near-infrared can provide important height variation information. However, at the diffraction-limited spatial resolution of the telescope, the spectral data is photon starved due to the decreased spectral passband.

  2. High throughput, detailed, cell-specific neuroanatomy of dendritic spines using microinjection and confocal microscopy

    PubMed Central

    Dumitriu, Dani; Rodriguez, Alfredo; Morrison, John H.

    2012-01-01

    Morphological features such as size, shape and density of dendritic spines have been shown to reflect important synaptic functional attributes and potential for plasticity. Here we describe in detail a protocol for obtaining detailed morphometric analysis of spines using microinjection of fluorescent dyes, high resolution confocal microscopy, deconvolution and image analysis using NeuronStudio. Recent technical advancements include better preservation of tissue resulting in prolonged ability to microinject, and algorithmic improvements that compensate for the residual Z-smear inherent in all optical imaging. Confocal imaging parameters were probed systematically for the identification of both optimal resolution as well as highest efficiency. When combined, our methods yield size and density measurements comparable to serial section transmission electron microscopy in a fraction of the time. An experiment containing 3 experimental groups with 8 subjects in each can take as little as one month if optimized for speed, or approximately 4 to 5 months if the highest resolution and morphometric detail is sought. PMID:21886104

  3. Chromatic confocal microscopy for multi-depth imaging of epithelial tissue.

    PubMed

    Olsovsky, Cory; Shelton, Ryan; Carrasco-Zevallos, Oscar; Applegate, Brian E; Maitland, Kristen C

    2013-05-01

    We present a novel chromatic confocal microscope capable of volumetric reflectance imaging of microstructure in non-transparent tissue. Our design takes advantage of the chromatic aberration of aspheric lenses that are otherwise well corrected. Strong chromatic aberration, generated by multiple aspheres, longitudinally disperses supercontinuum light onto the sample. The backscattered light detected with a spectrometer is therefore wavelength encoded and each spectrum corresponds to a line image. This approach obviates the need for traditional axial mechanical scanning techniques that are difficult to implement for endoscopy and susceptible to motion artifact. A wavelength range of 590-775 nm yielded a >150 µm imaging depth with ~3 µm axial resolution. The system was further demonstrated by capturing volumetric images of buccal mucosa. We believe these represent the first microstructural images in non-transparent biological tissue using chromatic confocal microscopy that exhibit long imaging depth while maintaining acceptable resolution for resolving cell morphology. Miniaturization of this optical system could bring enhanced speed and accuracy to endomicroscopic in vivo volumetric imaging of epithelial tissue.

  4. Ultrahigh-speed, phase-sensitive full-field interferometric confocal microscopy for quantitative microscale physiology

    PubMed Central

    Sencan, Ikbal; Huang, Brendan K.; Bian, Yong; Mis, Emily; Khokha, Mustafa K.; Cao, Hui; Choma, Michael

    2016-01-01

    We developed ultra-high-speed, phase-sensitive, full-field reflection interferometric confocal microscopy (FFICM) for the quantitative characterization of in vivo microscale biological motions and flows. We demonstrated 2D frame rates in excess of 1 kHz and pixel throughput rates up to 125 MHz. These fast FFICM frame rates were enabled by the use of a low spatial coherence, high-power laser source. Specifically, we used a dense vertical cavity surface emitting laser (VCSEL) array that synthesized low spatial coherence light through a large number of narrowband, mutually-incoherent emitters. Off-axis interferometry enabled single-shot acquisition of the complex-valued interferometric signal. We characterized the system performance (~2 μm lateral resolution, ~8 μm axial gating depth) with a well-known target. We also demonstrated the use of this highly parallelized confocal microscopy platform for visualization and quantification of cilia-driven surface flows and cilia beat frequency in an important animal model (Xenopus embryos) with >1 kHz frame rate. Such frame rates are needed to see large changes in local flow velocity over small distance (high shear flow), in this case, local flow around a single ciliated cell. More generally, our results are an important demonstration of low-spatial coherence, high-power lasers in high-performance, quantitative biomedical imaging. PMID:27896006

  5. Technique of laser confocal and Raman spectroscopy for living cell analysis

    NASA Astrophysics Data System (ADS)

    Meng, Xiaochen; Zhu, Lianqing

    2013-10-01

    Because of the shortcomings of the main methods used to analysis single cell, the need of single living cell analysis with no damage, unmarked and in situ dynamic multi-parameter measurement is urgent in the life sciences and biomedical advanced research field. And the method of for living cells analysis is proposed. The spectral pretreatment technology of living cell is the key work of laser confocal Raman spectroscopy. To study the spectrum processing methods for Raman spectrum on single living cell and develop the pre-process techniques to enhance the signal-to-noise ratio, sensitivity, and decrease the influence of fluorescence, elimination the cosmic rays was used to improve the spectrum. The classification, average and filtration of spectrum were applied to enhance signal-to-noise ratio. The fluorescence was depressed for quantity analysis or utilized for analysis by comparing the background and the spectrum. The results show that the proposed technique for laser confocal Raman spectrum of single cell can perform the sensitive and weak intensity peaks and reflect the information of molecules structures very well.

  6. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy.

    PubMed

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 μm. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

  7. Spectral imaging technique for retinal perfusion detection using confocal scanning laser ophthalmoscopy

    NASA Astrophysics Data System (ADS)

    Rasta, Seyed Hossein; Manivannan, Ayyakkannu; Sharp, Peter F.

    2012-11-01

    To evaluate retinal perfusion in the human eye, a dual-wavelength confocal scanning laser ophthalmoscope (cSLO) was developed that provides spectral imaging of the fundus using a combination of red (670 nm) and near-infrared (810 nm) wavelengths. The image of the ocular fundus was analyzed to find out if quantitative measurements of the reflectivity of tissue permit assessment of the oxygen perfusion of tissue. We explored problems that affect the reproducibility of patient measurements such as non-uniformity errors on the image. For the first time, an image processing technique was designed and used to minimize the errors of oxygen saturation measurements by illumination correction in retina wide field by increasing SNR. Retinal images were taken from healthy and diabetic retinopathy eyes using the cSLO with a confocal aperture of 100 μm. The ratio image (RI) of red/IR, as oxygen saturation (SO2) index, was calculated for normal eyes. The image correction technique improved the reproducibility of the measurements. Average RI intensity variation of healthy retina tissue was determined within a range of about 5.5%. The capability of the new technique to discriminate oxygenation levels of retinal artery and vein was successfully demonstrated and showed good promise in the diagnosis of the perfused retina.

  8. Confocal mosaicing microscopy in skin excisions: a demonstration of rapid surgical pathology

    PubMed Central

    Gareau, D.S.; Patel, Y.G.; Li, Y.; Aranda, I.; Halpern, A.C.; Nehal, K.S.; Rajadhyaksha, M.

    2009-01-01

    Summary Precise micro-surgical removal of tumour with minimal damage to the surrounding normal tissue requires a series of excisions, each guided by an examination of frozen histology of the previous. An example is Mohs surgery for the removal of basal cell carcinomas (BCCs) in skin. The preparation of frozen histology is labour-intensive and slow. Confocal microscopy may enable rapid detection of tumours directly in surgical excisions with minimal need for frozen histology. Mosaicing of images enables observation of nuclear and cellular morphology in large areas of surgically excised tissue. In skin, the use of 10–1% acetic acid as a reflectance contrast agent brightens nuclei in 0.5–5 min and enhances nuclear-to-dermis contrast and detectability of BCCs. A tissue fixture was engineered for precisely mounting surgical excisions to enable mosaicing of 36 × 36 images to create a field of view of 12 × 12 mm. This large field of view displays the excision at 2× magnification, similar to that routinely used by Mohs surgeons when examining frozen histology. Comparison of mosaics to histology demonstrates detectability of BCCs. Confocal mosaicing presently requires 9 min, instead of 20–45 min per excision for preparing frozen histology, and thus may provide a means for rapid pathology-at-the-bedside to expedite and guide surgery. PMID:19196421

  9. Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy

    SciTech Connect

    Sarmiento, Raymund; Cemine, Vernon Julius; Tagaca, Imee Rose; Salvador, Arnel; Mar Blanca, Carlo; Saloma, Caesar

    2007-11-01

    We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change.We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emittingp-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity.

  10. Confocal Laser Microscope Scanning Applied To Three-Dimensional Studies Of Biological Specimens.

    NASA Astrophysics Data System (ADS)

    Franksson, Olof; Liljeborg, Anders; Carlsson, Kjell; Forsgren, Per-Ola

    1987-08-01

    The depth-discriminating property of confocal laser microscope scanners can be used to record the three-dimensional structure of specimens. A number of thin sections (approx. 1 μm thick) can be recorded by a repeated process of image scanning and refocusing of the microscope. We have used a confocal microscope scanner in a number of feasibility studies to investigate its possibilities and limitations. It has proved to be well suited for examining fluorescent specimens with a complicated three-dimensional structure, such as nerve cells. It has also been used to study orchid seeds, as well as cell colonies, greatly facilitating evaluation of such specimens. Scanning of the specimens is performed by a focused laser beam that is deflected by rotating mirrors, and the reflected or fluorescent light from the specimen is detected. The specimen thus remains stationary during image scanning, and is only moved stepwise in the vertical direction for refocusing between successive sections. The scanned images consist of 256*256 or 512*512 pixels, each pixel containing 8 bits of data. After a scanning session a large number of digital images, representing consecutive sections of the specimen, are stored on a disk memory. In a typical case 200 such 256*256 images are stored. To display and process this information in a meaningful way requires both appropriate software and a powerful computer. The computer used is a 32-bits minicomputer equipped with an array processor (FPS 100). The necessary software was developed at our department.

  11. Elastic moduli of collagen gels can be predicted from two-dimensional confocal microscopy.

    PubMed

    Yang, Ya-Li; Leone, Lindsay M; Kaufman, Laura J

    2009-10-07

    We quantitatively compare data obtained from imaging two-dimensional slices of three-dimensional unlabeled and fluorescently labeled collagen gels with confocal reflectance microscopy (CRM) and/or confocal fluorescence microscopy (CFM). Different network structures are obtained by assembling the gels over a range of concentrations at various temperatures. Comparison between CRM and CFM shows that the techniques are not equally sensitive to details of network structure, with CFM displaying higher fidelity in imaging fibers parallel to the optical axis. Comparison of CRM of plain and labeled collagen gels shows that labeling itself induces changes in gel structure, chiefly through inhibition of fibril bundling. Despite these differences, image analyses carried out on two-dimensional CFM and CRM slices of collagen gels reveal identical trends in structural parameters as a function of collagen concentration and gelation temperature. Fibril diameter approximated from either CRM or CFM is in good accord with that determined via electron microscopy. Two-dimensional CRM images are used to show that semiflexible polymer theory can relate network structural properties to elastic modulus successfully. For networks containing bundled fibrils, it is shown that average structural diameter, rather than fibril diameter, is the length scale that sets the magnitude of the gel elastic modulus.

  12. In vivo fluorescence confocal microscopy: indocyanine green enhances the contrast of epidermal and dermal structures

    NASA Astrophysics Data System (ADS)

    Skvara, Hans; Kittler, Harald; Schmid, Johannes A.; Plut, Ulrike; Jonak, Constanze

    2011-09-01

    In recent years, in vivo skin imaging devices have been successfully implemented in skin research as well as in clinical routine. Of particular importance is the use of reflectance confocal microscopy (RCM) and fluorescence confocal microscopy (FCM) that enable visualization of the tissue with a resolution comparable to histology. A newly developed commercially available multi-laser device in which both technologies are integrated now offers the possibility to directly compare RCM with FCM. The fluorophore indocyanine green (ICG) was intradermally injected into healthy forearm skin of 10 volunteers followed by in vivo imaging at various time points. In the epidermis, accurate assessment of cell morphology with FCM was supplemented by identification of pigmented cells and structures with RCM. In dermal layers, only with FCM connective tissue fibers were clearly contoured down to a depth of more than 100 μm. The fluorescent signal still provided a favorable image contrast 24 and 48 hours after injection. Subsequently, ICG was applied to different types of skin diseases (basal cell carcinoma, actinic keratosis, seborrhoeic keratosis, and psoriasis) in order to demonstrate the diagnostic benefit of FCM when directly compared with RCM. Our data suggest a great impact of FCM in combination with ICG on clinical and experimental dermatology in the future.

  13. Automated detection of malignant features in confocal microscopy on superficial spreading melanoma versus nevi

    NASA Astrophysics Data System (ADS)

    Gareau, Dan; Hennessy, Ricky; Wan, Eric; Pellacani, Giovanni; Jacques, Steven L.

    2010-11-01

    In-vivo reflectance confocal microscopy (RCM) shows promise for the early detection of superficial spreading melanoma (SSM). RCM of SSM shows pagetoid melanocytes (PMs) in the epidermis and disarray at the dermal-epidermal junction (DEJ), which are automatically quantified with a computer algorithm that locates depth of the most superficial pigmented surface [DSPS(x,y)] containing PMs in the epidermis and pigmented basal cells near the DEJ. The algorithm uses 200 noninvasive confocal optical sections that image the superficial 200 μm of ten skin sites: five unequivocal SSMs and five nevi. The pattern recognition algorithm automatically identifies PMs in all five SSMs and finds none in the nevi. A large mean gradient ψ (roughness) between laterally adjacent points on DSPS(x,y) identifies DEJ disruption in SSM ψ = 11.7 +/- 3.7 [-] for n = 5 SSMs versus a small ψ = 5.5 +/- 1.0 [-] for n = 5 nevi (significance, p = 0.0035). Quantitative endpoint metrics for malignant characteristics make digital RCM data an attractive diagnostic asset for pathologists, augmenting studies thus far, which have relied largely on visual assessment.

  14. Plasmon resonance and the imaging of metal-impregnated neurons with the laser scanning confocal microscope

    PubMed Central

    Thompson, Karen J; Harley, Cynthia M; Barthel, Grant M; Sanders, Mark A; Mesce, Karen A

    2015-01-01

    The staining of neurons with silver began in the 1800s, but until now the great resolving power of the laser scanning confocal microscope has not been utilized to capture the in-focus and three-dimensional cytoarchitecture of metal-impregnated cells. Here, we demonstrate how spectral confocal microscopy, typically reserved for fluorescent imaging, can be used to visualize metal-labeled tissues. This imaging does not involve the reflectance of metal particles, but rather the excitation of silver (or gold) nanoparticles and their putative surface plasmon resonance. To induce such resonance, silver or gold particles were excited with visible-wavelength laser lines (561 or 640 nm), and the maximal emission signal was collected at a shorter wavelength (i.e., higher energy state). Because the surface plasmon resonances of noble metal nanoparticles offer a superior optical signal and do not photobleach, our novel protocol holds enormous promise of a rebirth and further development of silver- and gold-based cell labeling protocols. DOI: http://dx.doi.org/10.7554/eLife.09388.001 PMID:26670545

  15. Application of Sol-Gel Method as a Protective Layer on a Specular Reflective Surface for Secondary Reflector in a Solar Receiver

    SciTech Connect

    Afrin, Samia; Dagdelen, John; Ma, Zhiwen; Kumar, Vinod

    2017-01-01

    Highly-specular reflective surfaces that can withstand elevated-temperatures are desirable for many applications including reflective heat shielding in solar receivers and secondary reflectors, which can be used between primary concentrators and heat collectors. A high-efficiency, high-temperature solar receiver design based on arrays of cavities needs a highly-specular reflective surface on its front section to help sunlight penetrate into the absorber tubes for effective flux spreading. Since this application is for high-temperature solar receivers, this surface needs to be durable and to maintain its optical properties through the usable life. Degradation mechanisms associated with elevated temperatures and thermal cycling, which include cracking, delamination, corrosion/oxidation, and environmental effects, could cause the optical properties of surfaces to degrade rapidly in these conditions. Protected mirror surfaces for these applications have been tested by depositing a thin layer of SiO2 on top of electrodeposited silver by means of the sol-gel method. To obtain an effective thin film structure, this sol-gel procedure has been investigated extensively by varying process parameters that affect film porosity and thickness. Endurance tests have been performed in a furnace at 150 degrees C for thousands of hours. This paper presents the sol-gel process for intermediate-temperature specular reflective coatings and provides the long-term reliability test results of sol-gel protected silver-coated surfaces.

  16. Submerged Reflectance

    DTIC Science & Technology

    1976-08-01

    at 450 and viewed at 0* (i.e., viewed nor1al to the surface). Instruments for performing this particular bi-directional reflectance measurement are...are described below. 3.1 THEORY OF ABSOLUTE SUBMERGED REFLECTANCE MEASUREMENT An absolute measurement of the reflectance of a surface can be obtained by...relative reflectance measurement is shown in Figure 2. The irradiance across the target will vary within the field of view of the photometer because

  17. Synthesis of optical system from reflective surfaces

    NASA Astrophysics Data System (ADS)

    Zverev, Victor A.; Pozhinskaya, Irina I.; Sobolev, Kirill; Jurova, Svetlana

    1996-10-01

    The possible element of telescope optical system with the composite aperture can be two-mirror system, consisting of two confocal paraboloids (Mersen system). This system is an aplanatic anastigmat for infinite target. Its obvious deficiency is the image field curvature. The ways of its elimination are defined by the application of optical system. The possible versions of their constructive realization are considered.

  18. Focused ultrasonic beam behavior at a stress-free boundary and applicability for measuring nonlinear parameter in a reflection mode

    NASA Astrophysics Data System (ADS)

    Jeong, Hyunjo; Zhang, Shuzeng; Li, Xiongbing

    2017-02-01

    In this work, we employ a focused beam theory to modify the phase reversal at the stress-free boundary, and consequently enhance the second harmonic generation during its back-propagation toward the initial source position. We first confirmed this concept through experiment by using a spherically focused beam at the water-air interface, and measuring the reflected second harmonic and comparing with a planar wave reflected from the same stress-free or a rigid boundary. In order to test the feasibility of this idea for measuring the nonlinearity parameter of solids in a reflection mode, a focused nonlinear ultrasonic beam is modeled for focusing at and reflection from a stress-free boundary. A nonlinearity parameter expression is then defined together with diffraction and attenuation corrections.

  19. Photometric phase functions of common geologic minerals and applications to quantitative analysis of mineral mixture reflectance spectra

    NASA Technical Reports Server (NTRS)

    Mustard, John F.; Pieters, Carle M.

    1989-01-01

    The mass fractional abundance of components in intimately mixed, particulate surfaces is calculated from laboratory reflectance spectra using Hapke's (1981) model for bidirectional reflectance. It is found that a simplified version of the model is accurate to within 7 percent for mixtures not containing low albedo components. The model is not appropriate for mixtures with very low and high albedo components. Consideration is given to the possible improvement of the method's accuracy by using an empirical single-particle phase function to describe the scattering characteristics of all minerals, or by solving for the single-particle phase function of the minerals involved exactly using extensive bidirectional reflectance measurements and Hapke's equations for bidirectional reflectance. Also, the results are used to examine the general scattering behavior of particulate mineral surfaces.

  20. Design and error analysis of adjustable reflection-type magneto-optical photonic crystals for optical isolator application

    NASA Astrophysics Data System (ADS)

    Zamani, Mehdi; Ghanaatshoar, Majid

    2014-05-01

    We have performed a theoretical study on the case of reflection-type one-dimensional magnetophotonic crystals (MPCs) to establish a practical magneto-optical isolator (MOI). We have introduced thin MPC structures with concurrent high reflectance and large Kerr rotation for oblique incidence, and with the capability of being adjusted to perfect MOIs. It has been shown that the adjustment technique can also provide a framework for establishment of MPCs which are stable against fabrication and setup errors.