Microscopy -Optical Coherence Tomography News

Articles in category: Microscopy

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1. 250 kHz, 1.5 µm resolution SD-OCT for in-vivo cellular imaging of the human cornea
  
  Explore OSA | OSA Publishing Nov 29 2018 Microscopy , Ophthalmology
  
  We present the first spectral domain optical coherence tomography (SD-OCT) system that combines an isotropic imaging resolution of ~1.5 µm in biological tissue with a 250 kHz image acquisition rate, for in vivo non-contact, volumetric imaging of the cellular structure of the human cornea. OCT images of the healthy human cornea acquired with this system reveal the cellular structure of the corneal epithelium, cellular debris and mucin clusters in the tear film, the shape, size and spatial distribution of the sub-basal corneal nerves and keratocytes in the corneal stroma, as well as reflections from endothelial nuclei. The corneal images ...
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  Mentions: University of Waterloo Singapore Eye Research Institute Kostadinka K. Bizheva
2. Superparamagnetic graphene quantum dot as a dual‐modality contrast agent for confocal fluorescence microscopy and magnetomotive optical coherence tomography
  
  Explore Wiley Online Library Oct 22 2018 Microscopy
  
  A magnetic graphene quantum dot (MGQD) nanoparticle, synthesized by hydrothermally reducing and cutting graphene oxide‐iron oxide sheet, was demonstrated to possess the capabilities of simultaneous confocal fluorescence and magnetomotive optical coherence tomography (MMOCT) imaging. This MGQD shows low toxicity, significant tunable blue fluorescence and superparamagnetism, which can thus be used as a dual‐modality contrast agent for confocal fluorescence microscopy (CFM) and MMOCT. The feasibility of applying MGQD as a tracer of cells is shown by imaging and visualizing MGQD labeled cells using CFM and our in‐house MMOCT. Since MMOCT and CFM can offer anatomical structure and intracellular ...
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  Mentions: University of Sheffield Steven J. Matcher
3. Computer-Aided Diagnosis of Label-Free 3-D Optical Coherence Microscopy Images of Human Cervical Tissue
  
  Explore arxiv.org Oct 2 2018 Gynecology , Microscopy
  
  : Ultrahigh-resolution optical coherence microscopy (OCM) has recently demonstrated its potential for accurate diagnosis of human cervical diseases. One major challenge for clinical adoption, however, is the steep learning curve clinicians need to overcome to interpret OCM images. Developing an intelligent technique for computer-aided diagnosis (CADx) to accurately interpret OCM images will facilitate clinical adoption of the technology and improve patient care. Methods: 497 high-resolution 3-D OCM volumes (600 cross-sectional images each) were collected from 159 ex vivo specimens of 92 female patients. OCM image features were extracted using a convolutional neural network (CNN) model, concatenated with patient information (e.g ...
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  Mentions: Lehigh University Chao Zhou
4. A Novel OCT Design for Cultural Heritage Applications
  
  Explore Cambridge University Press Aug 12 2018 Art , Microscopy , NDE/NDT
  
  The object challenges presented by cultural heritage materials can serve as a catalyst for the development of novel characterization techniques.
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  Mentions: Northwestern University
5. Multimodal Optical Imaging for Pretreatment Evaluation for Cutaneous Microparticle Delivery
  
  Explore Home - ClinicalTrials.gov Jun 29 2018 Dermatology , Microscopy , Clinical Trials
  
  Brief Summary: The purpose of this study is to investigate how pretreatment with a topical medication for acne affects application and delivery of gold microparticles to the skin in acne patients. In addition, the investigators want to investigate the biodistribution of gold microparticles in pretreated skin and compare this with the biodistribution of untreated skin using the non-invasive imaging techniques optical coherence tomography and reflectance confocal microscopy. Reflectance Confocal Microscopy (RCM) and Optical Coherence Tomography (OCT) are non-invasive imaging technologies allowing for imaging of the upper skin layers. Gold microparticles have been shown to have a contrast effect on the ...
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6. Volumetric optical coherence microscopy with a high space-bandwidth-time product enabled by hybrid adaptive optics
  
  Explore OSA | OSA Publishing Jun 19 2018 Microscopy
  
  Optical coherence microscopy (OCM) is a promising modality for high resolution imaging, but has limited ability to capture large-scale volumetric information about dynamic biological processes with cellular resolution. To enhance the throughput of OCM, we implemented a hybrid adaptive optics (hyAO) approach that combines computational adaptive optics with an intentionally aberrated imaging beam generated via hardware adaptive optics. Using hyAO, we demonstrate the depth-equalized illumination and collection ability of an astigmatic beam compared to a Gaussian beam for cellular-resolution imaging. With this advantage, we achieved volumetric OCM with a higher space-bandwidth- time product compared to Gaussian-beam acquisition that employed focus-scanning ...
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  Mentions: Cornell University Steven G. Adie
7. Surface emitting laser, laser array, light source device, information acquisition device, and optical coherence tomography apparatus
  
  Explore uspto.gov Jun 5 2018 Microscopy , Patents , Tunable Sources
  
  Provided is a surface emitting laser that is to be excited by an external light source and in which a light-emitting position is defined. A surface emitting laser includes a pair of reflecting mirrors (11, 15) and an active layer (13) that is arranged between the pair of reflecting mirrors (11, 15) and that is to be excited by light that is radiated from an external light source. A gap is formed between the active layer and one of the pair of reflecting mirrors (15), the oscillation wavelength of the surface emitting laser is changed, and a defining structure (20 ...
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  Mentions: Canon Medical Systems
8. Microscopy system with auto-focus adjustment by low-coherence interferometry
  
  Explore uspto.gov Jun 5 2018 Microscopy , Patents
  
  Disclosed are several technical approaches of using low coherence interferometry techniques to create an autofocus apparatus for optical microscopy. These approaches allow automatic focusing on thin structures that are positioned closely to reflective surfaces and behind refractive material like a cover slip, and automated adjustment of focus position into the sample region without disturbance from reflection off adjacent surfaces. The measurement offset induced by refraction of material that covers the sample is compensated for. Proposed are techniques of an instrument that allows the automatic interchange of imaging objectives in a low coherence interferometry autofocus system, which is of major interest ...
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  Mentions: Thorlabs Alex E. Cable James Y. Jiang
9. Optical coherence tomography systems integrated with surgical microscopes
  
  Explore uspto.gov Mar 27 2018 Microscopy , Patents
  
  Some embodiments of the present inventive concept provide optical coherence tomography (OCT) systems for integration with a microscope. The OCT system includes a sample arm coupled to the imaging path of a microscope. The sample arm includes an input beam zoom assembly including at least two movable lenses configured to provide shape control for an OCT signal beam; a scan assembly including at least one scanning mirror and configured for telecentric scanning of the OCT signal beam; and a beam expander configured to set the OCT signal beam diameter incident on the microscope objective. The shape control includes separable controls ...
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  Mentions: Eric L. Buckland Bioptigen
10. Clinical Translation of Tethered Confocal Microscopy Capsule for Unsedated Diagnosis of Eosinophilic Esophagitis
  
  Explore Nature Publishing Group Feb 8 2018 Gastroenterology , Microscopy
  
  Esophagogastroduodenoscopy (EGD) is a widely used procedure, posing significant financial burden on both healthcare systems and patients. Moreover, EGD is time consuming, sometimes difficult to tolerate, and suffers from an imperfect diagnostic yield as the limited number of collected biopsies does not represent the whole organ. In this paper, we report on technological and clinical feasibility of a swallowable tethered endomicroscopy capsule, which is administered without sedation, to image large regions of esophageal and gastric mucosa at the cellular level. To demonstrate imaging capabilities, we conducted a human pilot study (n = 17) on Eosinophilic Esophagitis (EoE) patients and healthy volunteers ...
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  Mentions: Guillermo J. Tearney Massachusetts General Hospital Harvard University
11. Actinic Keratosis and Non-Invasive Diagnostic Techniques: An Update
  
  Explore MDPI Open Access Journals Platform Jan 8 2018 Dermatology , Microscopy , Oncology
  
  Actinic keratosis represents the earliest manifestation of non-melanoma skin cancer. Because of their risk of progression to invasive squamous cell carcinoma, an earlier diagnosis and treatment are mandatory. Their diagnosis sometimes could represent a challenge even for expert dermatologists. Dermoscopy, confocal laser microscopy and optical coherence tomography could help clinicians in diagnosis. .
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12. Visible Light Optical Coherence Microscopy of the Brain with Isotropic Femtoliter Resolution In Vivo
  
  Explore OSA | OSA Publishing Dec 2 2017 Microscopy , Neurology
  
  Most flying-spot Optical Coherence Tomography (OCT) and Optical Coherence Microscopy (OCM) systems use a symmetric confocal geometry, where the detection path retraces the illumination path starting from and ending with the spatial mode of a single mode optical fiber. Here, we describe a visible light OCM instrument that breaks this symmetry to improve transverse resolution without sacrificing collection efficiency. This was achieved by overfilling a water immersion objective on the illumination path, while maintaining a conventional Gaussian mode detection path (1/e2 intensity diameter ~0.82 Airy disks), enabling ~1.1 μm full-width at half-maximum (FWHM) transverse resolution. At the ...
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  Mentions: Vivek J. Srinivasan Stanford University UC Davis
13. Interferometric synthetic aperture microscopy for extended focus optical coherence microscopy
  
  Explore OSA | OSA Publishing Nov 28 2017 Microscopy
  
  Optical coherence microscopy (OCM) is an interferometric technique providing 3D images of biological samples with micrometric resolution and penetration depth of several hundreds of micrometers. OCM differs from optical coherence tomography (OCT) in that it uses a high numerical aperture (NA) objective to achieve high lateral resolution. However, the high NA also reduces the depth-of-field (DOF), scaling with 1/NA 2 . Interferometric synthetic aperture microscopy (ISAM) is a computed imaging technique providing a solution to this trade-off between resolution and DOF. An alternative hardware method to achieve an extended DOF is to use a non-Gaussian illumination. Extended focus OCM (xfOCM ...
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  Mentions: Ecole Polytechnique Fédérale de Lausanne Theo Lasser
14. Surgical microscope with integrated optical coherence tomography and display systems
  
  Explore uspto.gov Nov 28 2017 Microscopy , Ophthalmology , Patents
  
  An ophthalmic surgical microscope includes a beam coupler positioned along an optical path of the surgical microscope between a first eyepiece and magnifying/focusing optics, the beam coupler operable to direct the OCT imaging beam along a first portion of the optical path of the surgical microscope between the beam coupler and a patient's eye (an OCT image being generated based on a reflected portion of the OCT imaging beam). The surgical microscope additionally includes a real-time data projection unit operable to project the OCT image generated by the OCT system and a beam splitter positioned along the optical ...
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  Mentions: Lingfeng Yu
15. Real-time and non-invasive measurements of cell mechanical behaviour with optical coherence phase microscopy
  
  Explore ScienceDirect Nov 21 2017 Microscopy
  
  Cell mechanical behaviour is increasingly recognised as a central biophysical parameter in cancer and stem cell research, and methods of investigating their mechanical behaviour are therefore needed. We have developed a novel qualitative method based on quantitative phase imaging which is capable of investigating cell mechanical behaviour in real-time at cellular resolution using optical coherence phase microscopy (OCPM), and stimulating the cells non-invasively using hydrostatic pressure. The method was exemplified to distinguish between cells with distinct mechanical properties, and transient change induced by Cytochalasin D. We showed the potential of quantitative phase imaging to detect nanoscale intracellular displacement induced by ...
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16. Spectrally Encoded Coherence Tomography and Reflectometry (SECTR): simultaneous en face and cross-sectional imaging at 2 gigapixels-per-second
  
  Explore Wiley Online Library Nov 17 2017 Microscopy
  
  Non-invasive biological imaging is crucial for understanding in vivo structure and function. Optical coherence tomography (OCT) and reflectance confocal microscopy are two of the most widely used optical modalities for exogenous contrast-free high-resolution three-dimensional imaging in non-fluorescent scattering tissues. However, sample motion remains a critical barrier to raster-scanned acquisition and reconstruction of wide-field anatomically accurate volumetric datasets. We introduce spectrally encoded coherence tomography and reflectometry (SECTR), a high-speed multimodality system for simultaneous OCT and spectrally-encoded reflectance (SER) imaging. SECTR utilizes a robust system design consisting of shared optical relays, scanning mirrors, swept-laser, and digitizer to achieve the fastest reported in ...
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  Mentions: Vanderbilt University Yuankai K. Tao
17. Non-invasive evaluation of Secukinumab efficacy in severe plaque psoriasis with confocal microscopy and optical coherence tomography: A case report
  
  Explore Wiley Online Library Oct 25 2017 Dermatology , Microscopy
  
  Letter to the editor.
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18. Microscope-integrated intraoperative optical coherence tomography-guided small-incision lenticule extraction: New surgical technique
  
  Explore Journal of Cataract & Refractive Surgery Oct 1 2017 Microscopy , Ophthalmology
  
  We describe the surgical technique of microscope-integrated intraoperative optical coherence tomography (OCT)-guided small-incision lenticule extraction. The technique enables manual tracking of surgical instruments and identification of the desired dissection plane. It also helps discern the relation between the dissector and the intrastromal lenticule. The dissection plane becomes hyperreflective on dissection, ensuring complete separation of the intrastromal lenticule from the overlying and underlying stroma. Inadvertent posterior plane entry, cap–lenticule adhesion, incomplete separation of the lenticule, creation of a false plane, and lenticule remnants may be recognized intraoperatively so corrective steps can be taken immediately. In cases with a hazy ...
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19. 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
20. 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 Benjamin E. Sherlock
21. 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
22. 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
23. 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
24. 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
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