Microscopy -Optical Coherence Tomography News

Articles in category: Microscopy

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1. Methods and systems for characterizing laser machining properties by measuring keyhole dynamics using interferometry
  
  Explore uspto.gov Sep 12 2017 Microscopy , Patents
  
  A method, apparatus, and system are provided to monitor and characterize the dynamics of a phase change region (PCR) created during laser welding, specifically keyhole welding, and other material modification processes, using low-coherence interferometry. By directing a measurement beam to multiple locations within and overlapping with the PCR, the system, apparatus, and method are used to determine, in real time, spatial and temporal characteristics of the weld such as keyhole depth, length, width, shape and whether the keyhole is unstable, closes or collapses. This information is important in determining the quality and material properties of a completed finished weld. It ...
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  Mentions: Queen's University Canada
2. In vivo multiphoton microscopy using a handheld scanner with lateral and axial motion compensation
  
  Explore Wiley Online Library Aug 31 2017 Microscopy , Ophthalmology
  
  This paper reports a handheld multiphoton fluorescence microscope designed for clinical imaging that incorporates axial motion compensation and lateral image stabilization. Spectral domain optical coherence tomography is employed to track the axial position of the skin surface, and lateral motion compensation is realised by imaging the speckle pattern arising from the optical coherence tomography beam illuminating the sample. Our system is able to correct lateral sample velocities of up to ~65 μm s -1 . Combined with the use of negative curvature microstructured optical fibre to deliver tunable ultrafast radiation to the handheld multiphoton scanner without the need of a dispersion ...
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  Mentions: Imperial College London
3. Label-free three-dimensional imaging of Caenorhabditis elegans with visible optical coherence microscopy
  
  Explore Journals | PLOS Jul 20 2017 Microscopy
  
  Fast, label-free, high-resolution, three-dimensional imaging platforms are crucial for high-throughput in vivo time-lapse studies of the anatomy of Caenorhabditis elegans , one of the most commonly used model organisms in biomedical research. Despite the needs, methods combining all these characteristics have been lacking. Here, we present label-free imaging of live Caenorhabditis elegans with three-dimensional sub-micrometer resolution using visible optical coherence microscopy (visOCM). visOCM is a versatile optical imaging method which we introduced recently for tomography of cell cultures and tissue samples. Our method is based on Fourier domain optical coherence tomography, an interferometric technique that provides three-dimensional images with high sensitivity ...
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  Mentions: National Institutes of Health Thorlabs Cambridge Technology
4. Microscopic surgery system and navigation method guided by optical coherence tomography (OCT) and automated OCT imaging field calibration
  
  Explore uspto.gov Jul 4 2017 Microscopy , Patents
  
  Provided are a microscopic surgery system and a navigation method guided by optical coherence tomography. The microscopic surgery system may include: an object lens; a surgical microscope unit configured to perform two-dimensional imaging on an area to operate on via the object lens; an optical coherence tomography unit configured to perform two-dimensional tomography imaging on the area via the object lens, with an imaging field calibrated according to that of the surgical microscope unit; a processor configured to obtain navigation information based on the two-dimensional imaging by the surgical microscope unit and the two-dimensional tomography imaging by the optical coherence ...
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  Mentions: Chinese Academy of Sciences
5. Optical coherence microscopy as a novel, non-invasive method for the 4D live imaging of early mammalian embryos
  
  Explore Nature Publishing Group Jun 29 2017 Developmental Biology , Microscopy
  
  Imaging of living cells based on traditional fluorescence and confocal laser scanning microscopy has delivered an enormous amount of information critical for understanding biological processes in single cells. However, the requirement for a high numerical aperture and fluorescent markers still limits researchers’ ability to visualize the cellular architecture without causing short- and long-term photodamage. Optical coherence microscopy (OCM) is a promising alternative that circumvents the technical limitations of fluorescence imaging techniques and provides unique access to fundamental aspects of early embryonic development, without the requirement for sample pre-processing or labeling. In the present paper, we utilized the internal motion of ...
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  Mentions: Maciej Wojtkowski Nicolaus Copernicus University Maciej Szkulmowski
6. Temporal evolution of low-coherence reflectrometry signals in photoacoustic remote sensing microscopy
  
  Explore OSA | OSA Publishing Jun 17 2017 Microscopy
  
  Recently, a new noncontact reflection-mode imaging modality called photoacoustic remote sensing (PARS) microscopy was introduced providing optical absorption contrast. Unlike previous modalities, which rely on interferometric detection of a probe beam to measure surface oscillations, the PARS technique detects photoacoustic initial pressures induced by a pulsed laser at their origin by monitoring intensity modulations of a reflected probe beam. In this paper, a model describing the temporal evolution from a finite excitation pulse is developed with consideration given to the coherence length of the interrogation beam. Analytical models are compared with approximations, finite-difference time-domain (FDTD) simulations, and experiments with good ...
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  Mentions: University of Alberta
7. When pressure meets light: detecting the photoacoustic effect at the origin
  
  Explore Nature Publishing Group Jun 1 2017 Microscopy
  
  Modern optical microscopy¹, including confocal microscopy, two-photon microscopy and optical coherence tomography (OCT), has revolutionized life sciences by providing detailed information of biological samples with cellular and subcellular resolutions, and has become an essential tool for biomedical research labs. However, optical microscopy typically has a limited penetration depth of ~1 mm in biological tissue due to strong optical scattering^2, 3. Moreover, with respective contrast mechanisms, confocal and two-photon microscopy usually rely on fluorescent labeling of the samples and OCT still lacks sensitivity to many biological functions. In contrast, optical-resolution photoacoustic microscopy (OR-PAM) has emerged over the last decade ...
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  Mentions: Duke University
8. Perth Researchers Developed the World's Smallest Microscope
  
  Explore Latest Science News and Science Articles Apr 11 2017 Microscopy , Oncology
  
  One in four women who have a lump removed from their breast needs more surgery to remove remaining cancer cells. That’s a pretty scary statistic for patients. And it’s one Professor David Sampson believes could be better. “One of the main reasons [breast cancer patients need extra surgery] is because all of the tumour is not being identified. Because it can’t all be seen. Because you don’t have the resolution to see it.” David explains. “So in many instances, resolution – being able to see very small things – is a key part of improving those guidance procedures ...
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  Mentions: David D. Sampson University of Western Australia
9. Advances in Surgical Microscopes Pave the Way to Improved Outcomes
  
  Explore Photonics.com Apr 7 2017 Microscopy , Ophthalmology
  
  The new generation of devices can heighten resolution, integrate patient data with intraoperative images and allow for more exact localization of surgical targets. By integrating intelligence, video, intraoperative-imaging and navigation technologies, today’s surgical microscopes provide surgeons with insights to improve their decision-making at the point of care and provide patients with the best possible outcomes. Surgical microscopes enable physicians to perform delicate surgery through tiny incisions. With a microscope, a surgeon can visualize anatomy within small cavities not perceptible by the human eye alone. They have long been used for ophthalmology.
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  Mentions: Bioptigen Carl Zeiss Meditec Leica
10. Intraoperative 4-Dimensional Microscope-Integrated Optical Coherence TomographyGuided 27-Gauge Transvitreal Choroidal Biopsy for Choroidal Melanoma
  
  Explore LWW Online Mar 24 2017 Dermatology , Microscopy , Oncology , Ophthalmology
  
  Tissue sampling is desireable to understand prognostic genetic alternations in uveal melanoma...
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  Mentions: Joseph A. Izatt Duke University Cynthia A. Toth
11. Microscope-Integrated OCT Feasibility and Utility With the EnFocus System in the DISCOVER Study
  
  Explore Healio.com Mar 16 2017 Microscopy , Ophthalmology
  
  BACKGROUND AND OBJECTIVE: To evaluate the feasibility and utility of a novel microscope-integrated intraoperative optical coherence tomography (OCT) system. PATIENTS AND METHODS: The DISCOVER study is an investigational device study evaluating microscope-integrated intraoperative OCT systems for ophthalmic surgery. This report focuses on subjects imaged with the EnFocus prototype system (Leica Microsystems/Bioptigen, Morrisville, NC). OCT was performed at surgeon-directed milestones. Surgeons completed a questionnaire after each case to evaluate the impact of OCT on intraoperative management. RESULTS: Fifty eyes underwent imaging with the EnFocus system. Successful imaging was obtained in 46 of 50 eyes (92%). In eight cases (16%), surgical ...
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  Mentions: Cleveland Clinic Justis P. Ehlers Sunil K. Srivastava
12. 3D wide field-of-view Gabor-domain optical coherence microscopy advancing real-time in-vivo imaging and metrology
  
  Explore Conference Proceedings Mar 1 2017 Microscopy
  
  Real-time volumetric high-definition wide-field-of-view in-vivo cellular imaging requires micron-scale resolution in 3D. Compactness of the handheld device and distortion-free images with cellular resolution are also critically required for onsite use in clinical applications. By integrating a custom liquid lens-based microscope and a dual-axis MEMS scanner in a compact handheld probe, Gabor-domain optical coherence microscopy (GD-OCM) breaks the lateral resolution limit of optical coherence tomography through depth, overcoming the tradeoff between numerical aperture and depth of focus, enabling advances in biotechnology. Furthermore, distortion-free imaging with no post-processing is achieved with a compact, lightweight handheld MEMS scanner that obtained a 12-fold reduction ...
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  Mentions: University of Rochester Jannick P. Rolland UCLA
13. White matter segmentation by estimating tissue optical attenuation from volumetric OCT massive histology of whole rodent brains
  
  Explore Conference Proceedings Mar 1 2017 Microscopy , Neurology
  
  A whole rodent brain was imaged using an automated massive histology setup and an Optical Coherence Tomography (OCT) microscope. Thousands of OCT volumetric tiles were acquired, each covering a size of about 2.5x2.5x0.8 mm3 with a sampling resolution of 4.9x4.9x6.5 microns. This paper shows the techniques for reconstruction, attenuation compensation and segmentation of the sliced brains. The tile positions within the mosaic were evaluated using a displacement model of the motorized stage and pairwise coregistration. Volume blending was then performed by solving the 3D Laplace equation, and consecutive slices were assembled using the cross-correlation ...
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  Mentions: Polytechnique Montreal Frédéric Lesage
14. Optical coherence microscopy with extended focus for in vivo embryonic imaging
  
  Explore Conference Proceedings Feb 16 2017 Developmental Biology , Microscopy
  
  Optical coherence microscopy (OCM) has unique advantages of high-resolution volumetric imaging without relying on exogenous labels or dyes. It combines the coherence-gated depth discrimination of optical coherence tomography (OCT) with the high lateral resolution of confocal microscopy, offering an excellent balance between the resolutions and imaging depth. However, as the lateral resolution becomes higher, the imaging depth of OCM decreases and its three-dimensional imaging capability is greatly degraded. To overcome this limitation, we used amplitude apodization to create quasi-Bessel beam illumination in order to extend the depth of focus. The lateral and axial resolutions of our OCM system were measured ...
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  Mentions: University of Southern California Yu Chen Scott E. Fraser
15. Optical coherence tomography technique
  
  Explore uspto.gov Feb 7 2017 Microscopy , Ophthalmology , Patents
  
  An optical coherence tomography device comprises a light generator, a dispersive medium, an optical coupler and a detector. The light generator is adapted to generate a series of input pulses of coherent light, each input pulse having an input pulse width. The dispersive medium has an input that is optically coupled to the light generator and an output for output pulses. The dispersive medium is adapted to stretch the input pulse width to an output pulse width of each of the output pulses by chromatic dispersion. The optical coupler is adapted to couple the output pulses into a reference arm ...
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  Mentions: Henning Wisweh
16. Measurement of dynamic cell-induced 3D displacement fields in vitro for traction force optical coherence microscopy
  
  Explore OSA | OSA Publishing Feb 3 2017 Microscopy
  
  Traction force microscopy (TFM) is a method used to study the forces exerted by cells as they sense and interact with their environment. Cell forces play a role in processes that take place over a wide range of spatiotemporal scales, and so it is desirable that TFM makes use of imaging modalities that can effectively capture the dynamics associated with these processes. To date, confocal microscopy has been the imaging modality of choice to perform TFM in 3D settings, although multiple factors limit its spatiotemporal coverage. We propose traction force optical coherence microscopy (TF-OCM) as a novel technique that may ...
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  Mentions: Cornell University Steven G. Adie
17. Articular Cartilage Surface Topography and Roughness in Frozen Tissue Samples Using Optical Coherence Microscopy
  
  Explore nahje.com Feb 2 2017 Microscopy
  
  This paper describes a method to visualize the topography of the surface of cartilage. Optical Coherence Microscopy (OCM) technique has been used to get two dimensional images of frozen tissue samples of bovine articular cartilage. Optical Coherence Microscopy (OCM) is a combination of optical coherence tomography and confocal microscopy. Coherence gate from OCT and confocal gate from confocal microscopy can achieve higher resolution and deeper penetration depth. The precise three-dimensional topography of the cartilage surfaces has been obtained. The full-image roughness, for frozen samples has been obtained.
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18. Microscope-less wide field-of-view surgical OCT visualization system
  
  Explore uspto.gov Jan 31 2017 Microscopy , Patents
  
  A surgical imaging system can comprise a light source, configured to generate an imaging light beam; a beam guidance system, configured to guide the imaging light beam from the light source; a beam scanner, configured to receive the imaging light from the beam guidance system, and to generate a scanned imaging light beam; a beam coupler, configured to redirect the scanned imaging light beam; and a wide field of view (WFOV) lens, configured to guide the redirected scanned imaging light beam into a target region of a procedure eye.
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  Mentions: Lingfeng Yu
19. En face coherence microscopy [Invited]
  
  Explore OSA | OSA Publishing Jan 7 2017 Microscopy
  
  En face coherence microscopy or flying spot or full field optical coherence tomography or microscopy (FF-OCT/FF-OCM) belongs to the OCT family because the sectioning ability is mostly linked to the source coherence length. In this article we will focus our attention on the advantages and the drawbacks of the following approaches: en face versus B scan tomography in terms of resolution, coherent versus incoherent illumination and influence of aberrations, and scanning versus full field imaging. We then show some examples to illustrate the diverse applications of en face coherent microscopy and show that endogenous or exogenous contrasts can add ...
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  Mentions: Claude Boccara ESPCI ParisTech Kate Grieve
20. Postdoctoral Research Fellowships in In Vivo Microscopy at Massachusetts General Hosptial
  
  Explore Optical Coherence Tomography News Jan 4 2017 Microscopy , Jobs & Studentships
  
  Employer Description Until recently, visualizing the architectural and cellular morphology of human tissue has required histopathological examination. Samples would be excised from the patient, processed, sectioned, stained and viewed under a microscope. In addition to being invasive, time consuming and costly, the static nature of conventional pathology prohibits the study of biological dynamics and function. The Tearney Laboratory at Massachusetts General Hospital has led the way in transforming the current diagnostic paradigm through the invention and translation of new noninvasive, high-resolution optical imaging modalities that enable disease diagnosis from living patients without excising tissues from the body. Led by Guillermo ...
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  Mentions: Guillermo J. Tearney Massachusetts General Hospital Harvard University
21. Are patients capable and comfortable using mobile teledermoscopy?
  
  Explore Wiley Online Library Dec 19 2016 Dermatology , Microscopy , Oncology
  
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22. Introducing 3-D OCT to live surgery
  
  Explore Ophthalmology Times Dec 1 2016 Microscopy , Ophthalmology
  
  No doubt the commercialization of optical coherence tomography (OCT) has forever changed the clinical management of retinal disorders. Its introduction into the surgical realm may be a game changer in its own right, said Pravin U. Dugel, MD. Modern microscopes limit the surgeon’s view, and “axial information must be inferred from instrument shadowing and other indirect cues.” 1 As advances in OCT technology have increased the ability of these devices to image ocular structures better, the category as a whole has moved into a wide variety of applications, including the ability to assess subretinal fluid, pigment epithelial detachments, and ...
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  Mentions: University of Southern California
23. Imaging Microscopic Features of Keratoconic Corneal Morphology
  
  Explore LWW Online Nov 26 2016 Microscopy , Ophthalmology
  
  Purpose: To search for gold-standard histology indicators using alternative imaging modalities in keratoconic corneas. Methods: Prospective observational case–control study. Fourteen keratoconic corneas and 20 normal corneas (10 in vivo healthy subjects and 10 ex vivo donor corneas) were examined. Images of corneas were taken by spectral domain optical coherence tomography (SD-OCT) and in vivo confocal microscopy (IVCM) before keratoplasty. The same removed corneal buttons were imaged after keratoplasty with full-field optical coherence microscopy (FFOCM) and then fixed and sent for histology. Controls consisted of normal subjects imaged in vivo with IVCM and donor corneas imaged ex vivo with FFOCM ...
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  Mentions: National Institutes of Health Optovue University of Sheffield
24. Using light to map the circuitry of the brain
  
  Explore EurekAlert! Nov 18 2016 Microscopy , Neurology
  
  Lehigh University bio-engineers are first to explore the use of highly-sensitive, non-invasive optical coherence tomography (OCT) to examine neuron-to-neuron communication in live tissue. Scientific progress has provided a solid understanding of the anatomy of the brain. However, there is still no reliable way to examine neuron to neuron communication, as it happens--a key to understanding the correlation between brain structure and brain function. Chao Zhou , assistant professor of bioengineering at Lehigh University, likens our current brain-mapping ability to a Global Positioning System (GPS) that can help a user locate a city, but cannot offer a street-level view. With current imaging ...
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  Mentions: National Institutes of Health Lehigh University Chao Zhou
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