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Digital Imaging Systems (digital + imaging_system)
Selected AbstractsDigital imaging in transmission electron microscopyJOURNAL OF MICROSCOPY, Issue 1 2000G. Y. Fan The digital revolution currently under way, as evidenced by the rapid development of the Internet and the world-wide-web technologies, is undoubtedly impacting the field of transmission electron microscopy (TEM). Digital imaging systems based on charge-coupled device (CCD) technologies, with pixel array size up to 2 k × 2 k at the present and increasing, are available for TEM applications and offer many attractions. Is it time to phase out film cameras on TEMs and close the darkrooms for good? This paper reviews digital imaging technologies for TEM at different voltages, and contrasts the performance of digital imaging systems with that of TEM film. The performance characteristics of CCD-based digital imaging systems, as well as methods for assessing them, are discussed. Other approaches to digital imaging are also briefly reviewed. [source] A Quantitative Study of the Medial Surface Dynamics of an In Vivo Canine Vocal Fold during Phonation,THE LARYNGOSCOPE, Issue 9 2005Michael Doellinger PhD Abstract Objectives/Hypothesis: The purpose of this study was to measure the medial surface dynamics of a canine vocal fold during phonation. In particular, displacements, velocities, accelerations, and relative phase velocities of vocal fold fleshpoints were reported across the entire medial surface. Although the medial surface dynamics have a profound influence on voice production, such data are rare because of the inaccessibility of the vocal folds. Study Design: Medial surface dynamics were investigated during both normal and fry-like phonation as a function of innervation to the recurrent laryngeal nerve for conditions of constant glottal airflow. Methods: An in vivo canine model was used. The larynx was dissected similar to methods described in previous excised hemilarynx experiments. Phonation was induced with artificial airflow and innervation to the recurrent laryngeal nerve. The recordings were obtained using a high-speed digital imaging system. Three dimensional coordinates were computed for fleshpoints along the entire medial surface. The trajectories of the fleshpoints were preprocessed using the method of Empirical Eigenfunctions. Results: Although considerable variability existed within the data, in general, the medial-lateral displacements and vertical displacements of the vocal fold fleshpoints were large compared with anterior-posterior displacements. For both normal and fry-like phonation, the largest displacements and velocities were concentrated in the upper medial portion. During normal phonation, the mucosal wave propagated primarily in a vertical direction. Above a certain threshold of subglottal pressure (or stimulation to the recurrent laryngeal nerve), an abrupt transition from chest-like to fry-like phonation was observed. Conclusions: The study reports unique, quantitative data regarding the medial surface dynamics of an in vivo canine vocal fold during phonation, capturing both chest-like and fry-like vibration patterns. These data quantify a complex set of dynamics. The mathematical modeling of such complexity is still in its infancy and requires quantitative data of this nature for development, validation, and testing. [source] Comparison of the corneal endothelial protective effects of Healon-D and ViscoatCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 4 2009Carolee M Cutler Peck MD MPH Abstract Background:, The use of dispersive ophthalmic viscosurgical devices (OVDs) has been shown to provide significant protection against air bubble damage to the corneal endothelium when compared with cohesive OVDs. We compared the corneal endothelial protective effects of a new dispersive OVD, Healon-D, with Viscoat. Methods:, Healon-D and Viscoat were used in a randomized and masked fashion in the anterior chamber of 40 rabbit eyes during a procedure where ultrasound at 70% continuous energy was delivered for 2 min. Two millilitres of air bubbles were injected into the anterior chamber during the first minute of the procedure on each eye. Corneas were then stained with trypan blue and alizarin red and evaluated via light microscopy for endothelial injury. Both denuding of the endothelial layer, as well as damage to endothelial cells were quantified by using the Evaluation of Posterior Capsule Opacification digital imaging system. Results:, The denuded area for eyes treated with Healon-D and Viscoat were not significantly different (medians of 0.004167and 0.003333, respectively, P = 0.8908). There was no significant difference in the area of endothelial cell damaged (medians of 0.02183 and 0.01433, respectively, P = 0.4565). When the denuded and damaged areas were calculated together, there was also no difference in the total injured area (medians of 0.05817 and 0.05821, respectively, P = 0.5740). Conclusion:, The new dispersive OVD Healon-D is equally as effective as Viscoat in protecting the corneal endothelial layer from denuding and damage from air bubbles during anterior segment surgery. [source] Digital imaging in transmission electron microscopyJOURNAL OF MICROSCOPY, Issue 1 2000G. Y. Fan The digital revolution currently under way, as evidenced by the rapid development of the Internet and the world-wide-web technologies, is undoubtedly impacting the field of transmission electron microscopy (TEM). Digital imaging systems based on charge-coupled device (CCD) technologies, with pixel array size up to 2 k × 2 k at the present and increasing, are available for TEM applications and offer many attractions. Is it time to phase out film cameras on TEMs and close the darkrooms for good? This paper reviews digital imaging technologies for TEM at different voltages, and contrasts the performance of digital imaging systems with that of TEM film. The performance characteristics of CCD-based digital imaging systems, as well as methods for assessing them, are discussed. Other approaches to digital imaging are also briefly reviewed. [source] Megapixels, Millimetres and Microsieverts: Packaging Digital Photogrammetry for Emerging Industrial MarketsTHE PHOTOGRAMMETRIC RECORD, Issue 95 2000D. P. Chapman As the performance of megapixel digital imaging systems continues to improve, the rapid growth of high-end consumer markets drives prices ever lower. When such cameras are married with emerging, desktop "photogrammetric" software packages, the close range photogrammetric community is faced with many new challenges and opportunities. The dramatic changes in the technological arena are matched by a rapidly changing business environment in which concepts such as "Partnering" and "Supply chain management" have become key themes. As organizations of all sizes seek to thrive within this new business landscape, there appears to be a willingness to think more flexibly about the client-supplier relationship and the sharing of risks and rewards. This, in turn, has encouraged the development of highly customized measurement solutions across a wide range of market sectors. In each of these solutions the emphasis is not on a generic photogrammetric product, but on a highly tailored system tightly coupled to existing workflows, and focused on the specific needs of the client. Such systems pose particular challenges to their designers, since they are frequently operated by users with relatively little photogrammetric background and yet must always meet the challenging requirement of producing an output which is "fit for purpose". Thus this paper hopes to show how novel megapixel imaging systems can be configured to deliver flexible measurement systems capable of millimetric level accuracy within the challenging engineering environments typical of the nuclear and process industries (hence the microsievert component of the title). [source] Near-IR spectroscopic imaging for skin hydration: The long and the short of itBIOPOLYMERS, Issue 2 2002E. Michael Attas Abstract Near-IR spectroscopic methods have been developed to determine the degree of hydration of human skin in vivo. Noncontact reflectance spectroscopic imaging was used to investigate the distribution of skin moisture as a function of location. A human study in a clinical setting has generated quantitative data showing the effects of a drying agent and a moisturizer on delineated regions of the forearms of eight volunteers. Two digital imaging systems equipped with liquid-crystal tunable filters were used to collect stacks of monochromatic images at 10-nm intervals over the 650,1050 and 960,1700 nm wavelength bands. Synthetic images generated from measurements of water absorption band areas at three different near-IR wavelengths (970, 1200, and 1450 nm) showed obvious differences in the apparent distribution of water in the skin. Changes resulting from the skin treatments were much more evident in the long-wavelength images than in the short-wavelength ones. The variable sensitivity of the method at different wavelengths has been interpreted as being the result of different penetration depths of the IR light used in the reflectance studies. © 2002 John Wiley & Sons, Inc. Biopolymers (Biospectroscopy) 67: 96,106, 2002 [source] | ||||||||||