1. Institute of Applied Physics

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    1. Mentioned In 154 Articles

    2. Slow axis displacement correction for stripe artefact removal in optical coherence angiography

      Slow axis displacement correction for stripe artefact removal in optical coherence angiography
      The method for displacement correction along the slow axis of optical coherence tomography (OCT) data volumes is presented. The method is based on the recursive replacement of the next displaced OCT measurements by the weighted summation of itself and the previous OCT measurement in the slow axis dimension already corrected for the displacement. The values of the appropriate weight multipliers were defined from the local correlation of the two measurements ...
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    3. Calibration of Lateral Scanning in Optical Coherence Tomography Devices

      Calibration of Lateral Scanning in Optical Coherence Tomography Devices
      Methods for determining the dependence of the lateral-scan coordinate on the A-scan number from tomographic images of test samples are investigated and techniques for compensating for horizontal distortions of tomographic images caused by uneven speed of the probing-beam displacement are proposed. An opal-glass Ronchi ruling and an inclined flat surface of the volume-scattering plate were used as test samples .
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    4. Depth-resolved approach for the attenuation coefficient calculation from the Optical Coherence Tomography data and its application for the brain imaging

      Depth-resolved approach for the attenuation coefficient calculation from the Optical Coherence Tomography data and its application for the brain imaging
      Optical coherence tomography (OCT) is a promising tool for intraoperative tissue morphology determination. Several studies suggest that the attenuation coefficient, derived from the OCT images can differentiate between normal and tumorous tissues, as well as between gray and white brain matter. The methods used for attenuation coefficient derivation in these studies follow the assumption that the optical properties of the specimen are uniform within the OCT imaging depth range. Although ...
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    5. Strain and elasticity imaging in compression optical coherence elastography: the two‐decade perspective and recent advances

      Strain and elasticity imaging in compression optical coherence elastography: the two‐decade perspective and recent advances
      Quantitative mapping of deformation and elasticity in optical coherence tomography has attracted much attention of researchers during the last two decades. However, despite intense effort it took ~15years to demonstrate optical coherence elastography (OCE) as a practically useful technique. Similarly to medical ultrasound, where elastography was first realized using the quasi‐static compression principle and later shear‐wave‐based systems were developed, in OCE these two approaches also developed in ...
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    6. Histological validation of in vivo assessment of cancer tissue inhomogeneity and automated morphological segmentation enabled by Optical Coherence Elastography

      Histological validation of in vivo assessment of cancer tissue inhomogeneity and automated morphological segmentation enabled by Optical Coherence Elastography
      We present a non-invasive (albeit contact) method based on Optical Coherence Elastography (OCE) enabling the in vivo segmentation of morphological tissue constituents, in particular, monitoring of morphological alterations during both tumor development and its response to therapies. The method uses compressional OCE to reconstruct tissue stiffness map as the first step. Then the OCE-image is divided into regions, for which the Youngs modulus (stiffness) falls in specific ranges corresponding to ...
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    7. Magnetic Resonance Contrast Agents in Optical Clearing: Prospects for Multimodal Tissue Imaging

      Magnetic Resonance Contrast Agents in Optical Clearing: Prospects for Multimodal Tissue Imaging
      Skin optical clearing effect ex vivo and in vivo was achieved by topical application of low molecular weight paramagnetic magnetic resonance contrast agents. This novel feature has not been explored before. By using collimated transmittance the diffusion coefficients of three clinically used magnetic resonance contrast agents, i.e. Gadovist, Magnevist and Dotarem as well as X‐ray contrast agent Visipaque in mouse skin were determined ex vivo as (4.290 ...
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    8. Determination and correction of aberrations in full field OCT using phase gradient autofocus by maximizing the likelihood function

      Determination and correction of aberrations in full field OCT using phase gradient autofocus by maximizing the likelihood function
      A method for numerical estimation and correction of aberrations of the eye in fundus imaging with optical coherence tomography (OCT) is presented. Aberrations are determined statistically by using the estimate based on likelihood function maximization. The method can be considered as an extension of the phase gradient autofocusing algorithm in synthetic aperture radar imaging to 2D optical aberration correction. The efficacy of the proposed method has been demonstrated in OCT ...
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    9. TRANS-SEROSAL MULTIMODAL OPTICAL COHERENCE TOMOGRAPHY FOR VISUALIZATION OF MICROSTRUCTURE AND BLOOD CIRCULATION OF THE SMALL INTESTINE WALL

      TRANS-SEROSAL MULTIMODAL OPTICAL COHERENCE TOMOGRAPHY FOR VISUALIZATION OF MICROSTRUCTURE AND BLOOD CIRCULATION OF THE SMALL INTESTINE WALL
      The aim of the study was to evaluate the performance of trans-serosal multimodal OCT (MM OCT) in in vivo detecting of changes in microstructure and blood circulation of the small intestine wall caused by arteriovenous ischemia resulted from intestine strangulation. Materials and Methods. In experiments on Wistar rats (n=22), we examined the small intestine wall in vivo using MM OCT; the access to the intestine was reached through laparotomy ...
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    10. Application of Phase Correction for Compensation of Motion Artifacts in Spectral-Domain Optical Coherence Tomography

      Application of Phase Correction for Compensation of Motion Artifacts in Spectral-Domain Optical Coherence Tomography
      The application of computational methods to correct distortions in spectral-domain optical coherence tomography due to fast probe movements relative to a studied object is described. This technique is intended for use in endoscopy or in the study of external biological tissues using a handheld probe. The effectiveness of the method was confirmed experimentally.
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    11. Low-scattering volumes visualisation from optical coherence tomography data and its applications in otolaryngology

      Low-scattering volumes visualisation from optical coherence tomography data and its applications in otolaryngology
      The method for visualization of the low-scattering objects inside the bulk of the high-scattering tissue is presented. The method can contrast the low-scattering object of interest not only from the high scattering surroundings but from the noise region below the tissue image as well. The proposed method was applied for the visualization of the rodent and human cochlea volume.
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    12. Numerical method for axial motion artifact correction in retinal spectral-domain optical coherence tomography

      Numerical method for axial motion artifact correction in retinal spectral-domain optical coherence tomography
      A numerical method that compensates image distortions caused by random fluctuations of the distance to an object in spectral-domain optical coherence tomography (SD OCT) has been proposed and verified experimentally. The proposed method is based on the analysis of the phase shifts between adjacent scans that are caused by micrometer-scale displacements and the subsequent compensation for the displacements through phase-frequency correction in the spectral space. The efficiency of the method ...
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    13. Optical coherence angiography for pre-treatment assessment and treatment monitoring following photodynamic therapy: a basal cell carcinoma patient study

      Optical coherence angiography for pre-treatment assessment and treatment monitoring following photodynamic therapy: a basal cell carcinoma patient study
      Microvascular networks of human basal cell carcinomas (BCC) and surrounding skin were assessed with optical coherence angiography (OCA) in conjunction with photodynamic therapy (PDT). OCA images were collected and analyzed in 31 lesions pre-treatment, and immediately/24hours/312 months post-treatment. Pre-treatment OCA enabled differentiation between prevalent subtypes of BCC (nodular and superficial) and nodular-with-necrotic-core BCC subtypes with a diagnostic accuracy of 78%; this can facilitate more accurate biopsy reducing sampling ...
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    14. Spectral domain optical coherence tomography based imaging biomarkers for diabetic retinopathy

      Spectral domain optical coherence tomography based imaging biomarkers for diabetic retinopathy
      To evaluate the role of central subfield thickness (CST), cube average thickness (CAT), and cube volume (CV) as imaging biomarkers for severity of diabetic retinopathy within the ETDRS-based grades of retinopathy using spectral domain optical coherence tomography (SD-OCT). This study aims to evaluate the role of macular CST, CAT, and CV on SD-OCT as imaging biomarkers for severity of DR. One hundred ninety-four consecutive cases of type 2 diabetes mellitus ...
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    15. Full-Field Optical Coherence Tomography Based on a MII-4 Microprofilometer Using Microlenses with Air Immersion

      Full-Field Optical Coherence Tomography Based on a MII-4 Microprofilometer Using Microlenses with Air Immersion
      A modernized Linnik microprofilometer (MII-4) allowing the performing of tomographic investigation of transparent and relatively turbid media by the methods of low-coherence interferometry has been presented. The design of the reference channel of the standard MII-4 has been revised. A dynamic adjustment of the reference arm length has been added to compensate for the effect of divergence between focal and coherent volumes, as well as spherical aberration that occurs when ...
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  2. About Institute of Applied Physics

    Institute of Applied Physics

    Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS) was created by a Decree of the Soviet Government on July 28, 1976. Annually the IAP RAS performs about 350 scientific projects, funded by federal special programs, academic, industry, international and other programs and projects. Among the most prominent achievements of the Institute of Applied Physics RAS are the invention of gyrotrons and gyroklystrons and their upgrading to a high technical level, the development of effective methods to convert and transport powerful electromagnetic radiation, the elaboration of physical principles for excitation and reception of low-frequency sound fields in the ocean and the creation of hardware for hydroacoustics and long-term acoustical monitoring in the ocean, complexes for research of noise radiation characteristics of moving objects, the development of high-rate growth and precision processing of water-soluble crystals, developmet of optical coherent tomography to image biotissue structures and designing an optical tomograph for medical diagnostics of human internal organs  See IAP RAS OCT link HERE.