1. Featured Articles

    25-48 of 113 « 1 2 3 4 5 »
    1. Full-Field Optical Coherence Tomography of Human Donor and Pathological Corneas

      Full-Field Optical Coherence Tomography of Human Donor and Pathological Corneas

      Purpose : To evaluate the performance of a full-field optical coherence tomography (FF-OCT) system in the study of human donor and pathological corneas and assess its suitability for use in eye banks. Methods : Our study was carried out using an FF-OCT system developed for non-invasive imaging of tissue structures in depth with ultrahigh resolution (1 µm in all directions). Images were acquired from eight stored human donor corneas (either edematous or after deswelling) and five surgical specimens of corneas with various diseases (bullous keratopathy, lattice corneal dystrophy, stromal scar after keratitis, keratoconus and Fuchs dystrophy). They were compared with standard histology ...

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    2. Capabilities, limitations, and misconceptions of using OCT to assess vulnerable plaques

      Capabilities, limitations, and misconceptions of using OCT to assess vulnerable plaques

      Serious concerns exist about the Review by Otsuka et al . (Clinical classification of plaque morphology in coronary disease. Nat. Rev. Cardiol. 11, 379–389; 2014 ), 1 some of which are discussed in this Correspondence. The concerns are predominately about the authors' understanding of the principles and application of optical coherence tomography (OCT),

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    3. Automated identification of basal cell carcinoma by polarization-sensitive optical coherence tomography

      Automated identification of basal cell carcinoma by polarization-sensitive optical coherence tomography

      We report an automated classifier to detect the presence of basal cell carcinoma in images of mouse skin tissue samples acquired by polarization-sensitive optical coherence tomography (PS-OCT). The sensitivity and specificity of the classifier based on combined information of the scattering intensity and birefringence properties of the samples are significantly higher than when intensity or birefringence information are used alone. The combined information offers a sensitivity of 94.4% and specificity of 92.5%, compared to 78.2% and 82.2% for intensity-only information and 85.5% and 87.9% for birefringence-only information. These results demonstrate that analysis of the ...

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    4. 3D Polymer Weld Seam Characterization Based on Optical Coherence Tomography for Laser Transmission Welding Applications

      3D Polymer Weld Seam Characterization Based on Optical Coherence Tomography for Laser Transmission Welding Applications

      Laser transmission welding is an established single-stage plastic joining process, which enables hermetically sealed joints under the workpiece surface. The process requires joining partners with proper degrees of transmission and absorption to the processing wavelength. For reaching a stable process an in-process quality assurance is very valuable. Current monitoring systems have a limited usage, as no quantitative information of the weld itself is obtained without its destruction. In medical and pharmaceutical applications a weld with leakage is e.g. unacceptable. The main objective of this paper is the presentation of the optical coherence tomography as a tool for the quality ...

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    5. In vivo analysis of burns in a mouse model using spectroscopic optical coherence tomography

      In vivo analysis of burns in a mouse model using spectroscopic optical coherence tomography

      Spectroscopic analysis of biological tissues can provide insight into changes in structure and function due to disease or injury. Depth-resolved spectroscopic measurements can be implemented for tissue imaging using optical coherence tomography (OCT). Here, spectroscopic OCT is applied to in vivo measurement of burn injury in a mouse model. Data processing and analysis methods are compared for their accuracy. Overall accuracy in classifying burned tissue was found to be as high as 91%, producing an area under the curve of a receiver operating characteristic curve of 0.97. The origins of the spectral changes are identified by correlation with histopathology.

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    6. Orion is in Beta - Voxeleron prepares the release of their advanced OCT analysis software

      Orion is in Beta - Voxeleron prepares the release of their advanced OCT analysis software

      Orion™, Voxeleron’s advanced optical coherence tomography (OCT) analysis software, is currently being beta tested at a number of sites in the USA and Europe in preparation for release. Orion™ is an application that offers fully-automated, rapid and accurate segmentation of seven layers in OCT images of the human retina. Following the successful release of InSight , Voxeleron’s animal OCT package, Orion™ establishes Voxeleron as leaders in the development of OCT image analysis software. "The Orion software gives us the ability to measure the thickness of the nuclear layers in isolation, so is a welcome addition to our quantification tools ...

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    7. Two-dimensional optical coherence tomography for real-time structural dynamical characterization

      Two-dimensional optical coherence tomography for real-time structural dynamical characterization

      We present a two-dimensional optical coherence vibration tomography (2DOCVT) system with an ultra-precision displacement resolution of ~0.1 nm that is capable of in site real-time absolute displacement measurement of structural line vibrations. Experimental results of sinusoidal, sweep and impulse vibrations were reported. The key figures of merit such as the 2DOCVT system could obtain fast line vibration measurement without scanning and it also could be used to capture structural modal parameters in one single impulse excitation measurement without any vibration excitation input information, making it attractive for the application in low-frequency vibration measurement and response-only modal analysis.

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    8. Detection of plasmonic nanoparticles with full field-OCT: optical and photothermal detection

      Detection of plasmonic nanoparticles with full field-OCT: optical and photothermal detection

      Detecting the signal backscattered by nanoparticles immersed in highly scattering media such as biological tissue remains a challenge. In this article we report on the use of Full Field OCT (FF-OCT) to slice in depth in phantoms and in tissues in order a) to selectively observe the particles through the backscattered light at suitable wavelengths, and b) to detect the effects of the time-dependent response to full field optical heating through the strong absorption cross-section of these plasmonic nanoparticles. The analysis of the thermal wave behavior leads to the localization of the heat sources even when FF-OCT signals cannot reach ...

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    9. St. Jude Medical Announces Launch of OPTIS Integrated System

      St. Jude Medical Announces Launch of OPTIS Integrated System

      The OPTIS™ Integrated System combines OCT imaging with angiography to provide more detailed, on-demand coronary assessment for more accurate PCI guidanc e St. Jude Medical, Inc. (NYSE:STJ), a global medical device company, today announced the company has secured CE Mark and FDA clearance for the new OPTIS Integrated System. The system is a departure from traditional, mobile cart-based diagnostic tools and advances percutaneous coronary intervention (PCI) optimization via direct installation into a hospital’s cardiac catheterization laboratory, fully integrating optical coherence tomography (OCT) and fractional flow reserve (FFR) into PCI workflow. The approval of the OPTIS Integrated system marks ...

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    10. Quantitative measurements of strain and birefringence with common-path polarization-sensitive optical coherence tomography

      Quantitative measurements of strain and birefringence with common-path polarization-sensitive optical coherence tomography

      We demonstrate the first system for optical coherence tomography (OCT) that enables simultaneous measurement of quantitative birefringence and strain in biological samples using a common-path configuration. Owing to its superior phase stability, common-path polarization sensitive optical coherence tomography (CoPPSe-OCT) achieves a sub-nanometer displacement sensitivity of 0.52 nm at an SNR of 48 dB. We utilize CoPPSe-OCT to measure reflectance, birefringence, and strain for distinguishing burnt regions in a birefringent biological sample (chicken breast muscle).

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    11. In vivo functional microangiography by visible-light optical coherence tomography

      In vivo functional microangiography by visible-light optical coherence tomography

      Although hemoglobin oxygen saturation (sO 2 ) in the microvasculature is an essential physiological parameter of local tissue functions, non-invasive measurement of microvascular sO 2 is still challenging. Here, we demonstrated that visible-light optical coherence tomography (vis-OCT) can simultaneously provide three-dimensional anatomical tissue morphology, visualize microvasculature at the capillary level, and measure sO 2 from the microvasculature in vivo . We utilized speckle contrast caused by the moving blood cells to enhance microvascular imaging. We applied a series of short-time inverse Fourier transforms to obtain the spectroscopic profile of blood optical attenuation, from which we quantified sO 2 . We validated the sO ...

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    12. Point-of-care and point-of-procedure optical imaging technologies for primary care and global health

      Point-of-care and point-of-procedure optical imaging technologies for primary care and global health

      Leveraging advances in consumer electronics and wireless telecommunications, low-cost, portable optical imaging devices have the potential to improve screening and detection of disease at the point of care in primary health care settings in both low- and high-resource countries. Similarly, real-time optical imaging technologies can improve diagnosis and treatment at the point of procedure by circumventing the need for biopsy and analysis by expert pathologists, who are scarce in developing countries. Although many optical imaging technologies have been translated from bench to bedside, industry support is needed to commercialize and broadly disseminate these from the patient level to the population ...

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    13. Fully automated detection of diabetic macular edema and dry age-related macular degeneration from optical coherence tomography images

      Fully automated detection of diabetic macular edema and dry age-related macular degeneration from optical coherence tomography images

      We present a novel fully automated algorithm for the detection of retinal diseases via optical coherence tomography (OCT) imaging. Our algorithm utilizes multiscale histograms of oriented gradient descriptors as feature vectors of a support vector machine based classifier. The spectral domain OCT data sets used for cross-validation consisted of volumetric scans acquired from 45 subjects: 15 normal subjects, 15 patients with dry age-related macular degeneration (AMD), and 15 patients with diabetic macular edema (DME). Our classifier correctly identified 100% of cases with AMD, 100% cases with DME, and 86.67% cases of normal subjects. This algorithm is a potentially impactful ...

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    14. Automatic detection of bioresorbable vascular scaffold struts in intravascular optical coherence tomography pullback runs

      Automatic detection of bioresorbable vascular scaffold struts in intravascular optical coherence tomography pullback runs

      Bioresorbable vascular scaffolds (BVS) have gained significant interest in both the technical and clinical communities as a possible alternative to metallic stents. For accurate BVS analysis, intravascular optical coherence tomography (IVOCT) is currently the most suitable imaging technique due to its high resolution and the translucency of polymeric BVS struts for near infrared light. However, given the large number of struts in an IVOCT pullback run, quantitative analysis is only feasible when struts are detected automatically. In this paper, we present an automated method to detect and measure BVS struts based on their black cores in IVOCT images. Validated using ...

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    15. Bioptigen Introduces Deep Imaging OCT System for Contact Lens Metrology

      Bioptigen Introduces Deep Imaging OCT System for Contact Lens Metrology

      Bioptigen announced today the availability of a newly developed deep imaging OCT system for the optical device metrology and pre-clinical ophthalmic research markets. The Envisu S4410 SDOCT for Contact Lens Metrology is designed for non-destructive, non-contact, full immersion measurements for standard and high complexity contact lens, IOL structures, and donor tissues. The metrology system allows imaging of a complete contact lens immersed in a hydration bath (saline), automated segmentation of anterior and posterior surfaces, and quantification of curvatures across both surfaces. The system delivers 5 um axial pixel resolution, 11 mm scan depth in saline, and a full 20mm lateral ...

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      Mentions: Bioptigen
    16. Tornado Spectral Systems Announces Investment by Beauvest & Roadmap Captial

      Tornado Spectral Systems Announces Investment by Beauvest & Roadmap Captial

      Strategic Growth Round to Accelerate Global Expansion of Process Analyzers and Spectrometers-On-Chip Tornado Spectral Systems Inc., an emerging tech company developing radically superior tools for measuring the chemical composition and structure of materials in real-time for a variety of demanding industrial processes, announced additional funding led by venture capital firms BeauVest and Roadmap Capital. The new investments will be used to finance Tornado’s continued growth in North America and globally. With proprietary optical and nanophotonic technologies that overcome the limitations of conventional spectroscopy-based analyzers, Tornado Spectral Systems has developed a new class of instruments that can acquire chemical signatures ...

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    17. Optical coherence tomography: A new strategy to image planarian regeneration

      Optical coherence tomography: A new strategy to image planarian regeneration

      The planarian is widely used as a model for studying tissue regeneration. In this study, we used optical coherence tomography (OCT) for the real-time, high-resolution imaging of planarian tissue regeneration. Five planaria were sliced transversely to produce 5 head and 5 tail fragments. During a 2-week regeneration period, OCT images of the planaria were acquired to analyze the signal attenuation rates, intensity ratios, and image texture features (including contrast, correlation, homogeneity, energy, and entropy) to compare the primitive and regenerated tissues. In the head and tail fragments, the signal attenuation rates of the regenerated fragments decreased from −0.2 dB ...

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    18. OCT 3-D surface topography of isolated human crystalline lenses

      OCT 3-D surface topography of isolated human crystalline lenses

      Quantitative 3-D Optical Coherence Tomography was used to measure surface topography of 36 isolated human lenses, and to evaluate the relationship between anterior and posterior lens surface shape and their changes with age. All lens surfaces were fitted to 6th order Zernike polynomials. Astigmatism was the predominant surface aberration in anterior and posterior lens surfaces (accounting for ~55% and ~63% of the variance respectively), followed by spherical terms, coma, trefoil and tetrafoil. The amount of anterior and posterior surface astigmatism did not vary significantly with age. The relative angle between anterior and posterior surface astigmatism axes was on average 36 ...

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    19. Video Interview on Optical coherence tomography as a tool for in vivo staging and grading of upper urinary tract urothelial cell carcinoma: Comparison with biopsies and histopathology of the resected specimen

      Video Interview on Optical coherence tomography as a tool for in vivo staging and grading of upper urinary tract urothelial cell carcinoma: Comparison with biopsies and histopathology of the resected specimen

      Introduction and Objectives: Optical Coherence Tomography (OCT) has potential to provide real-time information on UUT-UC grade and stage. In this study we compare a) biopsy and b) OCT with gold standard histopathology of the resected specimen (HRS) for grading and staging of low- and high-grade UUT-UC. Methods: 16 patients with UUT-UC underwent diagnostic URS, including OCT and biopsy of places with visible tumour. The 2.7 Fr OCT probe was delivered through the ureteroscopes work channel. Subsequently biopsy was performed. At a later stage, patients underwent nephroureterectomy. For staging by OCT, in-house developed protocols were used and visible lesions were ...

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    20. Performance of megahertz amplified optical time-stretch optical coherence tomography (AOT-OCT)

      Performance of megahertz amplified optical time-stretch optical coherence tomography (AOT-OCT)

      Enabled by the ultrahigh-speed all-optical wavelength-swept mechanism and broadband optical amplification, amplified optical time-stretch optical coherence tomography (AOT-OCT) has recently been demonstrated as a practical alternative to achieve ultrafast A-scan rate of multi-MHz in OCT. With the aim of identifying the optimal scenarios for MHz operation in AOT-OCT, we here present a theoretical framework to evaluate its performance metric. In particular, the analysis discusses the unique features of AOT-OCT, such as its superior coherence length, and the relationship between the optical gain and the A-scan rate. More importantly, we evaluate the sensitivity of AOT-OCT in the MHz regime under the ...

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    21. Postdoctoral and PhD-student positions at Utsunomiya University, Japan

      Postdoctoral and PhD-student positions at Utsunomiya University, Japan

      PhD graduates with experience in retinal imaging, adaptive optics or polarization are invited to apply for a postdoctoral position. PhD positions are available for MSc students with a degree in optics, applied physics, computer science or electrical engineering. We also regularly have students and postdocs visit for a short-term internship (3 months, 6 months, etc). Please inquire if you are interested in an internship. Our goal is to build practical OCT instrumentation for the early detection of retinal diseases such as glaucoma and age related macular degeneration. To achieve this goal, we are using optical technologies: optical coherence tomography, polarization ...

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      Mentions: Barry Cense
    22. Optical diagnostics for Upper Urinary Tract Urothelial cancer: technology, thresholds and clinical applications

      Optical diagnostics for Upper Urinary Tract Urothelial cancer: technology, thresholds and clinical applications

      Purpose: Developments in optical diagnostics have potential for less invasive diagnose of upper urinary tract urothelial carcinoma (UUT-UC). This systematic review provides an overview of technology, applications and limitations of recently developed optical diagnostics in the upper urinary tract and outlines their potential for future clinical applications. In addition, current evidence was evaluated. Literature search: A PubMed literature search was performed and papers on Narrow Band Imaging (NBI), Photodynamic Diagnosis (PDD), Storz Professional Imaging Enhancement System (SPIES), Optical Coherence Tomography (OCT) and Confocal Laser Endomicroscopy (CLE) regarding UUT-UC were reviewed for data extraction. Study quality was reviewed according to QUADAS ...

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    23. Endothelial Shear Stress and Coronary Plaque Characteristics in Humans: A Combined Frequency-Domain Optical Coherence Tomography and Computational Fluid Dynamics Study

      Endothelial Shear Stress and Coronary Plaque Characteristics in Humans: A Combined Frequency-Domain Optical Coherence Tomography and Computational Fluid Dynamics Study

      Background —Despite the exposure of the entire vasculature to the atherogenic effects of systemic risk factors, atherosclerotic plaques preferentially develop at sites with disturbed flow. This study aimed at exploring in vivo the relationship between local endothelial shear stress (ESS) and coronary plaque characteristics in humans, using computational fluid dynamics and frequency-domain optical coherence tomography (FD-OCT). Methods and Results —Three-dimensional coronary artery reconstruction was performed in 21 patients (24 arteries) presenting with acute coronary syndrome using FD-OCT and coronary angiography. Each coronary artery was divided into sequential 3-mm segments, and analyzed for the assessment of local ESS and plaque characteristics ...

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    24. Post-Doc Position for biomedical engineer / vision scientist in small animal High-Resolution Retinal Imaging Group at University of California, Davis

      Post-Doc Position for biomedical engineer / vision scientist in small animal High-Resolution Retinal Imaging Group at University of California, Davis

      Applications are invited for a post-doctoral research associate position in the UC Davis EyePod Small Animal Imaging Laboratory in the Department of Cell Biology and Human Anatomy at the UC Davis Main Campus. The goal of our research is to develop the next generation in vivo small animal cellular resolution multimodal retinal imaging instruments to study age-related changes in vision and retinal disorders. The ideal candidate will have strong skills in some combination of retinal/microscopic imaging modalities, including but not limited to adaptive optics (AO), OCT, SLO, multispectral imaging, fluorescence, etc. Knowledge of programming languages (e.g. C++, LabView ...

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    25-48 of 113 « 1 2 3 4 5 »
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