1. Featured Articles

    25-41 of 41 « 1 2
    1. An efficient phase analysis-based wavenumber linearization scheme for swept source optical coherence tomography systems

      An efficient phase analysis-based wavenumber linearization scheme for swept source optical coherence tomography systems

      This letter reports an efficient phase analysis-based direct time domain resampling scheme for swept source-based optical coherence tomography (SS-OCT) systems. The unwrapped phase values, representing non-linear frequency sweeping of the laser, are extracted from the calibration signal generated by a Mach–Zehnder interferometer. Equidistant wavenumber spaces are calculated by normalizing obtained phase values followed by scaling to the maximum number of sampling points. The non-uniform fractional time index values corresponding to the uniformly distributed phase values are computed directly from the linearizer coordinates in order to eliminate the use of the polynomial fitting approach that is used in existing phase-based ...

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    2. HAAG-STREIT SURGICAL: iOCT® camera receives 510(k) clearance

      HAAG-STREIT SURGICAL: iOCT® camera receives 510(k) clearance

      HAAG-STREIT SURGICAL announced its intraoperative-OCT camera has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) for marketing on the largest medical device market in the world. The intraoperative Optical Coherence Tomography (iOCT®) is already being successfully used for cataract operations, lamellar keratoplasties, membrane peelings, and for the treatment of retinal disorders. The ASCRS congress, to be held in San Diego (18 – 21 April 2015), marks the launch of the iOCT® system in the US. During the course of the surgical procedure, the iOCT® system allows non-invasive, contact-free imaging so that the structures and layers within ...

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    3. Wasatch Photonics launches travel grants to celebrate International Year of Light

      Wasatch Photonics launches travel grants to celebrate International Year of Light

      Wasatch Photonics Inc. , a leading provider for gratings, spectrometer and optical coherence tomography instrumentation, is celebrating the International Year of Light and Light-based Technologies by launching its Travel and Publication Grant Program. The United Nations General Assembly proclaimed 2015 to be the International Year of Light and Light-based Technologies in December 2013. Mike Sullivan, general manager of Wasatch Photonics, said the Wasatch program supports research exchange by providing special grants to some of its customers for travel to academic meetings and publications. "The grants will support part of travel or publication cost. Wasatch has made it clear that while the ...

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    4. Internal fingerprint zone detection in optical coherence tomography fingertip scans

      Internal fingerprint zone detection in optical coherence tomography fingertip scans

      Optical coherence tomography (OCT) is a high-resolution imaging technology capable of capturing a three-dimensional (3-D) representation of fingertip skin. The papillary junction—a junction layer of skin containing the same topographical features as the surface fingerprint—is contained within this representation. The top edge of the papillary junction contains the topographical information pertinent to the internal fingerprint. Extracting the internal fingerprint from OCT fingertip scans has been shown to be possible. Currently, acquiring the internal fingerprint involves manually defining the region containing it. This manner of definition is inefficient. Perfect knowledge of the location of the papillary junction is hypothesized ...

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    5. Ultra-high resolution Fourier domain optical coherence tomography for old master paintings

      Ultra-high resolution Fourier domain optical coherence tomography for old master paintings

      In the last 10 years, Optical Coherence Tomography (OCT) has been successfully applied to art conservation, history and archaeology. OCT has the potential to become a routine non-invasive tool in museums allowing cross-section imaging anywhere on an intact object where there are no other methods of obtaining subsurface information. While current commercial OCTs have shown potential in this field, they are still limited in depth resolution (> 4 μm in paint and varnish) compared to conventional microscopic examination of sampled paint cross-sections (~1 μm). An ultra-high resolution fiber-based Fourier domain optical coherence tomography system with a constant axial resolution of 1 ...

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    6. Iowa State University veterinary researchers study retinal scans as early detection method for mad cow disease

      Iowa State University veterinary researchers study retinal scans as early detection method for mad cow disease

      New research from Iowa State University shows that a fatal neurological disease in cows can be detected earlier by examining the animal’s retinas. Bovine spongiform encephalopathy (BSE), known more commonly as mad cow disease, is an untreatable neurodegenerative disorder caused by misfolded brain proteins known as prions. Classic BSE incubates for years before producers or veterinarians notice symptoms, usually discovered when the animal can no longer stand on its own. But Heather Greenlee, an associate professor of biomedical sciences in Iowa State’s College of Veterinary Medicine , said studying the retinas of cattle can identify infected animals up to ...

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    7. Dimensional metrology of lab-on-a-chip internal structures: a comparison of optical coherence tomography with confocal fluorescence microscopy

      Dimensional metrology of lab-on-a-chip internal structures: a comparison of optical coherence tomography with confocal fluorescence microscopy

      Summary The characterization of internal structures in a polymeric microfluidic device, especially of a final product, will require a different set of optical metrology tools than those traditionally used for microelectronic devices. We demonstrate that optical coherence tomography (OCT) imaging is a promising technique to characterize the internal structures of poly(methyl methacrylate) devices where the subsurface structures often cannot be imaged by conventional wide field optical microscopy. The structural details of channels in the devices were imaged with OCT and analyzed with an in-house written ImageJ macro in an effort to identify the structural details of the channel. The ...

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    8. A Promising Future for Optical Coherence Tomography Angiography

      A Promising Future for Optical Coherence Tomography Angiography

      This Viewpoint reports on optical coherence tomography angiography and how its use could greatly enrich our understanding of the ischemic processes affecting different layers of the retinal vasculature. Fluorescein angiography has been the gold standard imaging modality for the retinal vasculature since its groundbreaking introduction in 1961 by Alvis and Novotny and has revolutionized our ability to diagnose diseases of the retinal vasculature and to identify retinal and choroidal neovascularization. 1 Its greatest advantage may lie in its ability to detect dynamic patterns of dye transit and leakage. Various innovations have broadened the use of angiography, including the application of ...

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    9. 4D optical coherence tomography-based micro-angiography achieved by 1.6-MHz FDML swept source

      4D optical coherence tomography-based micro-angiography achieved by 1.6-MHz FDML swept source

      We demonstrate the use of an ultra-high-speed swept-source optical coherence tomography (OCT) to achieve optical micro-angiography (OMAG) of microcirculatory tissue beds in vivo . The system is based on a 1310-nm Fourier domain mode-locking (FDML) laser with 1.6-MHz A-line rate, providing a frame rate of 3.415 KHz, an axial resolution of ∼ 10     μ m and signal to noise ratio of 102 dB. Motion from blood flow causes change in OCT signals between consecutive B-frames acquired at the same location. Intensity-based inter-frame subtraction algorithm is applied to extract blood flow from tissue background without any motion correction. We demonstrate the capability ...

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    10. Optical coherence tomography for nondestructive evaluation of fuel rod degradation

      Optical coherence tomography for nondestructive evaluation of fuel rod degradation

      Nuclear power plants regularly inspect fuel rods to ensure safe and reliable operation. Excessive corrosion can cause fuel failures which can have significant repercussions for the plant, including impacts on plant operation, worker exposure to radiation, and the plant's INPO rating. While plants typically inspect for fuel rod corrosion using eddy current techniques, these techniques have known issues with reliability in the presence of tenacious, ferromagnetic crud layers that can deposit during operation, and the nondestructive evaluation (NDE) inspection results can often be in error by a factor of 2 or 3. For this reason, alternative measurement techniques, such ...

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    11. Systems Engineer Position Opening at Topcon Medical Systems in Oakland, New Jersey

      Systems Engineer Position Opening at Topcon Medical Systems in Oakland, New Jersey

      An exciting opportunity for a highly motivated system engineer to work creatively within a dedicated R&D laboratory (Topcon Advanced Biomedical Imaging Laboratory, Oakland, NJ) contributing to interdisciplinary projects with global impact. Primary responsibilities include system development for ophthalmic imaging devices, supporting both prototype and commercial system development efforts. The position requires diverse engineering and programming experience including system integration, data acquisition and test equipment control, signal and image processing, and image analysis algorithm development. While this position has an emphasis on system development, the successful candidate is also expected to participate in advanced ophthalmic imaging techniques and imaging analysis ...

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    12. Assessing microstructures of the cornea with Gabor-domain optical coherence microscopy: pathway for corneal physiology and diseases

      Assessing microstructures of the cornea with Gabor-domain optical coherence microscopy: pathway for corneal physiology and diseases

      Gabor-domain optical coherence microscopy (GD-OCM) was applied ex vivo in the investigation of corneal cells and their surrounding microstructures with particular attention to the corneal endothelium. Experiments using fresh pig eyeballs, excised human corneal buttons from patients with Fuchs’ endothelial dystrophy (FED), and healthy donor corneas were conducted. Results show in a large field of view ( 1     mm × 1     mm ) high definition images of the different cell types and their surrounding microstructures through the full corneal thickness at both the central and peripheral locations of porcine corneas. Particularly, an image of the endothelial cells lining the bottom of the cornea ...

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    13. 1.7-μm spectroscopic spectral-domain optical coherence tomography for imaging lipid distribution within blood vessel

      1.7-μm spectroscopic spectral-domain optical coherence tomography for imaging lipid distribution within blood vessel

      We have developed a spectroscopic optical coherence tomography (OCT) for imaging lipid distribution within blood vessel in order to detect coronary artery plaque. A 1.7-μm spectral-domain OCT with A-scan rate of 47 kHz is fabricated using a broadband light source based on super-luminescent diodes and spectrometers based on extended InGaAs line sensors. We demonstrate imaging of lipid distribution in an in vitro artery model with lipid. The sensitivity and specificity in the differentiation between artery and lipid are 87% and 90% in the training, respectively. The validation test also shows detection of lipid with an accuracy over 90%.

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    14. Blood flow velocity vector field reconstruction from dual-beam bidirectional Doppler OCT measurements in retinal veins

      Blood flow velocity vector field reconstruction from dual-beam bidirectional Doppler OCT measurements in retinal veins

      In this paper, we demonstrate the possibility to reconstruct the actual blood flow velocity vector field in retinal microvessels from dual-beam bidirectional Doppler optical coherence tomography measurements. First, for a better understanding of measured phase patterns, several flow situations were simulated on the basis of the known dual beam measurement geometry. We were able to extract the vector field parameters that determine the measured phase pattern, allowing for the development of an algorithm to reconstruct the velocity vector field from measured phase data. In a next step, measurements were performed at a straight vessel section and at a venous convergence ...

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    15. The Arden Photonics OCT validation Phantom

      The Arden Photonics OCT validation Phantom

      The Arden Photonics OCT validation Phantom has been developed to assure the performance standards of your instruments throughout their life. This unique product uses a laser-inscribed calibration pattern embedded in a stable silica substrate, allowing inspection with an optical microscope. Independent verification can therefore, easily be used to check the accuracy of the phantom when conducting tests. With the OCT validation Phantom from Arden Photonics, you can be assured of the accuracy of your OCT images. Features and benefits: Four different patterns in one small slide gives comprehensive assessment of your OCT instrumentation Patterns laser-inscribed in silica for excellent stability ...

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      Mentions: Arden Photonics
    16. John S. Werner, UC Davis neuroscientist recognized for color vision and aging contributions

      John S. Werner, UC Davis neuroscientist recognized for color vision and aging contributions

      John S. Werner, a UC Davis neuroscientist and international authority on visual perception, has been selected to receive the 2015 Verriest Medal from the International Colour Vision Society for his contributions to understanding the structural and functional basis of color vision, how and why vision changes across the life span, and factors that contribute to loss of vision associated with disease. He will receive the award at the society’s biennial symposium in Sendai, Japan, in July. John Werner Understanding, monitoring visual mechanisms A distinguished professor at the UC Davis Eye Center and director of the Vision Science and Advanced ...

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    17. Ultrahigh speed en face OCT capsule for endoscopic imaging

      Ultrahigh speed en face OCT capsule for endoscopic imaging

      Depth resolved and en face OCT visualization in vivo may have important clinical applications in endoscopy. We demonstrate a high speed, two-dimensional (2D) distal scanning capsule with a micromotor for fast rotary scanning and a pneumatic actuator for precision longitudinal scanning. Longitudinal position measurement and image registration were performed by optical tracking of the pneumatic scanner. The 2D scanning device enables high resolution imaging over a small field of view and is suitable for OCT as well as other scanning microscopies. Large field of view imaging for screening or surveillance applications can also be achieved by proximally pulling back or ...

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    25-41 of 41 « 1 2
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