1. Articles from Alexander I. Omelchenko

    1-3 of 3
    1. Optical coherence elastography for strain dynamics measurements in laser correction of cornea shape

      Optical coherence elastography for strain dynamics measurements in laser correction of cornea shape

      We describe the use of elastographic processing in phase-sensitive optical coherence tomography (OCT) for visualizing dynamics of strain and tissue-shape changes during laser-induced photothermal corneal reshaping, for applications in the emerging field of non-destructive and non-ablative (non-LASIK) laser vision correction. The proposed phase-processing approach based on fairly sparse data acquisition enabled rapid data processing and near-real-time visualization of dynamic strains. The approach avoids conventional phase unwrapping, yet allows for mapping strains even for significantly supra-wavelength inter-frame displacements of scatterers accompanied by multiple phase-wrapping. These developments bode well for real-time feedback systems for controlling the dynamics of corneal deformation with 10 ...

      Read Full Article
    2. Multiparameter thermo-mechanical OCT-based characterization of laser-induced cornea reshaping

      Multiparameter thermo-mechanical OCT-based characterization of laser-induced cornea reshaping

      Phase-sensitive optical coherence tomography (OCT) is used for visualizing dynamic and cumulative strains and corneashape changes during laser-produced tissue heating. Such non-destructive (non-ablative) cornea reshaping can be used as a basis of emerging technologies of laser vision correction. In experiments with cartilaginous samples, polyacrilamide phantoms and excised rabbit eyes we demonstrate ability of the developed OCT system to simultaneously characterize transient and cumulated strain distributions, surface displacements, scattering tissue properties and possibility of temperature estimation via thermal-expansion measurements. The proposed approach can be implemented in perspective real-time OCT systems for ensuring safety of new methods of laser reshaping of cornea.

      Read Full Article
    3. Optical coherence tomography for visualizing transient strains and measuring large deformations in laser-induced tissue reshaping

      Optical coherence tomography for visualizing transient strains and measuring large deformations in laser-induced tissue reshaping

      In the context of the development of emerging laser-assisted thermo-mechanical technologies for non-destructive reshaping of avascular collagenous tissues (cartilages and cornea), we report the first application of phase-sensitive optical coherence tomography (OCT) for visualizing transient strains involving supra-wavelength inter-frame displacements of scatterers. Usually phase-sensitive OCT assumes the visualization of sub-pixel and even sub-wavelength displacements of scatterers and fairly small strains (say, <10 −3 ), which conventionally implies the necessity of averaging for enhancing the effective signal-to-noise ratio and, correspondingly, the application of small-amplitude actuators producing periodic deformations. The original approach used here allows for direct estimation of elevated strains ~10 −2 ...

      Read Full Article
    1-3 of 3
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Topics in the News

    1. (3 articles) Grigory V. Gelikonov
    2. (2 articles) Nizhny Novgorod State Medical Academy
    3. (2 articles) Institute of Applied Physics
    4. (2 articles) University of Toronto
    5. (2 articles) I. Alex Vitkin
  3. Popular Articles

  4. Picture Gallery

    Optical coherence tomography for visualizing transient strains and measuring large deformations in laser-induced tissue reshaping Multiparameter thermo-mechanical OCT-based characterization of laser-induced cornea reshaping Optical coherence elastography for strain dynamics measurements in laser correction of cornea shape Measurement of the Shrinkage of Natural and Simulated Lesions on Root Surfaces using CP-OCT Optic-Net: A Novel Convolutional Neural Network for Diagnosis of Retinal Diseases from Optical Tomography Images Double layer sign: A new optical coherence tomography finding in active tubercular serpiginous-like choroiditis to monitor activity Influence of Epiretinal Membranes on the Retinal Nerve Fiber Layer Thickness Measured by Spectral Domain Optical Coherence Tomography in Glaucoma High signal-to-noise ratio reconstruction of low bit-depth optical coherence tomography using deep learning New Method of Quantitative Analysis of Hard Exudate Using Optical Coherence Tomography: Application in Diabetic Macular Edema Characterization and oxygen saturation study of human retinal blood vessels evaluated by spectroscopic Optical Coherence Tomography Angiography Optical coherence tomography angiography and arterial hypertension: A role in identifying subclinical microvascular damage? Enhanced Depth Imaging Optical Coherence Tomography of Optic Nerve Head Drusen in Children