1. Articles from roman v. kuranov

    1-14 of 14
    1. Visible-Light Optical Coherence Tomography Fibergraphy for Quantitative Imaging of Retinal Ganglion Cell Axon Bundles

      Visible-Light Optical Coherence Tomography Fibergraphy for Quantitative Imaging of Retinal Ganglion Cell Axon Bundles

      Purpose : To develop a practical technique for visualizing and quantifying retinal ganglion cell (RGC) axon bundles in vivo. Methods : We applied visible-light optical coherence tomography (vis-OCT) to image the RGC axon bundles, referred to as vis-OCT fibergraphy, of healthy wild-type C57BL/6 mice. After vis-OCT imaging, retinas were flat-mounted, immunostained with anti-beta-III tubulin (Tuj1) antibody for RGC axons, and imaged with confocal microscopy. We quantitatively compared the RGC axon bundle networks imaged by in vivo vis-OCT and ex vivo confocal microscopy using semi-log Sholl analysis. Results : Side-by-side comparison of ex vivo confocal microscopy and in vivo vis-OCT confirmed that vis-OCT ...

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    2. Designing visible-light optical coherence tomography towards clinics

      Designing visible-light optical coherence tomography towards clinics

      Background: The capabilities of visible-light optical coherence tomography (vis-OCT) in noninvasive anatomical and functional retinal imaging have been demonstrated by multiple groups in both rodents and healthy human subjects. Translating laboratory prototypes to an integrated clinical-environment-friendly system is required to explore the full potential of vis-OCT in disease management. Methods: We developed and optimized a portable vis-OCT system for human retinal imaging in clinical settings. We acquired raster- and circular-scan images from both healthy and diseased human eyes. Results: The new vis-OCT provided high-quality retinal images of both subjects without any known eye diseases and patients with various retinal diseases ...

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    3. Group Refractive Index Measurement of Liquids Using Common-Path Swept Source Optical Coherence Tomography

      Group Refractive Index Measurement of Liquids Using Common-Path Swept Source Optical Coherence Tomography

      A fiber-optic based common-path swept source optical coherence tomography for a simple and high-resolution measurement of the group refractive indices of liquids has been investigated. The group refractive index measurement has been based on the optical length change before and after injection of liquid into a transparent glass tube. The gas-cell referenced fiber based common-path swept source optical coherence tomography instrument was utilized to obtain the group refractive indices of liquids. The standard deviations of the group refractive indices measured by this method were about 1 × 10–4. The measurement results on the group refractive indices of liquids showed an ...

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    4. Feature Of The Week 5/26/2013: University of Texas at Austin Investigates Dual-Wavelength Photothermal OCT for Imaging Microvasculature Blood Oxygen Saturation

      Feature Of The Week 5/26/2013: University of Texas at Austin Investigates Dual-Wavelength Photothermal OCT for Imaging Microvasculature Blood Oxygen Saturation

      A swept-source dual-wavelength photothermal optical coherence tomography (DWP-OCT) is demonstrated for imaging and measurement of microvasculature oxygen saturation (SO2). DWP-OCT is capable of recording three-dimensional images of tissue and depth-resolved phase variation in response to photothermal excitations in two different wavelengths (770 and 800 nm). Two phantom microvessels with different inner-diameter size (50 and 300 μm) were constructed, porcine blood with various SO2 levels were prepared for the experiment. Phantom microvessels were imaged and blood SO2 levels measured using DWP-OCT are compared with values provided by a commercial oximeter. Propagation error analysis suggests DWP-OCT is feasible for measurement of blood ...

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    5. Dual-wavelength photothermal optical coherence tomography for imaging microvasculature blood oxygen saturation

      Dual-wavelength photothermal optical coherence tomography for imaging microvasculature blood oxygen saturation

      A swept-source dual-wavelength photothermal (DWP) optical coherence tomography (OCT) system is demonstrated for quantitative imaging of microvasculature oxygen saturation. DWP-OCT is capable of recording three-dimensional images of tissue and depth-resolved phase variation in response to photothermal excitation. A 1,064-nm OCT probe and 770-nm and 800-nm photothermal excitation beams are combined in a single-mode optical fiber to measure microvasculature hemoglobin oxygen saturation ( SO 2 ) levels in phantom blood vessels with a range of blood flow speeds (0 to 17     mm / s ). A 50- μ m-diameter blood vessel phantom is imaged, and SO 2 levels are measured using DWP-OCT and compared with ...

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    6. Dual-wavelength photothermal optical coherence tomography for blood oxygen saturation measurement

      Dual-wavelength photothermal optical coherence tomography for blood oxygen saturation measurement

      We report design and demonstration of a dual wavelength photothermal (DWP) optical coherence tomography (OCT) system for imaging of a phantom microvessel and measurement of hemoglobin oxygen saturation (SO 2 ) level. The DWP-OCT system contains a swept-source (SS) two-beam phase-sensitive (PhS) OCT system (1060 nm) and two intensity modulated photothermal excitation lasers (770 nm and 800 nm). The PhS-OCT probe beam (1060 nm) and photothermal excitation beams are combined into one single-mode optical fiber. A galvanometer based two-dimensional achromatic scanning system is designed to provide 14 μm lateral resolution for the PhS-OCT probe beam (1060 nm) and 13 μm lateral ...

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    7. Feature Of The Week 1/22/12: In vivo depth-resolved oxygen saturation by dual-wavelength photothermal (DWP) OCT.

      Feature Of The Week 1/22/12: In vivo depth-resolved oxygen saturation by dual-wavelength photothermal (DWP) OCT.
      All mammalian tissues need oxygen for survival. The human body has a delicately organized vascular network that supplies our tissue with oxygen and other nutrients as well as removing waist products. Not surprisingly, aberrations in vascular oxygen supply are implicated in at least 70 diseases and that number continues to grow. The oxygen distribution from vascular hemoglobin to the parenchymal cells begins with oxygen diffusion first from arterioles with diameters less than 50 µm, and second from capillaries, with deoxygenated blood draining back to venules where the blood is redirected to the lungs for re-oxygenation. The earliest abnormalities in oxygen ...
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    8. In vivo depth-resolved oxygen saturation by dual-wavelength photothermal (DWP) OCT

      In vivo depth-resolved oxygen saturation by dual-wavelength photothermal (DWP) OCT
      Microvasculature hemoglobin oxygen saturation (SaO2) is important in the progression of various pathologies. Non-invasive depth-resolved measurement of SaO2 levels in tissue microvasculature has the potential to provide early biomarkers and a better understanding of the pathophysiological processes allowing improved diagnostics and prediction of disease progression. We report proof-of-concept in vivo depth-resolved measurement of SaO2 levels in selected 30 µm diameter arterioles in the murine brain using Dual-Wavelength Photothermal (DWP) Optical Coherence Tomography (OCT) with 800 nm and 770 nm photothermal excitation wavelengths. Depth location of back-reflected light from a target arteriole was confirmed using Doppler and speckle contrast OCT images ...
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    9. Depth-resolved blood oxygen saturation measurement by dual-wavelength photothermal (DWP) optical coherence tomography

      Depth-resolved blood oxygen saturation measurement by dual-wavelength photothermal (DWP) optical coherence tomography
      Non-invasive depth-resolved measurement of hemoglobin oxygen saturation (SaO2) levels in discrete blood vessels may have implications for diagnosis and treatment of various pathologies. We introduce a novel Dual-Wavelength Photothermal (DWP) Optical Coherence Tomography (OCT) for non-invasive depth-resolved measurement of SaO2 levels in a blood vessel phantom. DWP OCT SaO2 is linearly correlated with blood-gas SaO2 measurements. We demonstrate 6.3% precision in SaO2 levels measured a phantom blood vessel using DWP-OCT with 800 and 765 nm excitation wavelengths. Sources of uncertainty in SaO2 levels measured with DWP-OCT are identified and characterized.
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    10. Comparison of pulsed photothermal radiometry, optical coherence tomography and ultrasound for melanoma thickness measurement in PDMS tissue phantoms

      Comparison of pulsed photothermal radiometry, optical coherence tomography and ultrasound for melanoma thickness measurement in PDMS tissue phantoms

      Melanoma accounts for 75% of all skin cancer deaths. Pulsed photothermal radiometry (PPTR), optical coherence tomography (OCT) and ultrasound (US) are non-invasive imaging techniques that may be used to measure melanoma thickness, thus, determining surgical margins. We constructed a series of PDMS tissue phantoms simulating melanomas of different thicknesses. PPTR, OCT and US measurements were recorded from PDMS tissue phantoms and results were compared in terms of axial imaging range, axial resolution and imaging time. A Monte Carlo simulation and three-dimensional heat transfer model was constructed to simulate PPTR measurement. Experimental results show that PPTR and US can provide a ...

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    11. Gas-Cell Referenced Swept Source Phase Sensitive Optical Coherence Tomography

      Gas-Cell Referenced Swept Source Phase Sensitive Optical Coherence Tomography
      Distinct reference and signal interferometers in combination with a gas-cell spectral reference are employed to increase sensitivity and environmental stability of a swept source phase-sensitive optical coherence tomography. A displacement sensitivity (DS) of 65 pm at 280- $muhbox{m}$ depth and DS degradation with depth of 0.0015 rad/mm is achieved. Differential DS of 234 pm in a 127-$muhbox{m}$ -thick scattering phantom is six-fold superior to previously reported values. DS degradation with a depth of 0.026 rad/mm is reported for tissue-like scattering phantoms. Measured depth-dependent DS suggests that digitization time jitter noise contributes to degradation ...
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    12. Near infrared femtosecond laser ablation of urinary calculi in water

      Pulsed light emitted from a near infrared (=800nm) femtosecond laser is capable of plasma induced photodisruption of various materials. We used femtosecond laser pulses to ablate human urinary calculi. Femtosecond pulsed laser interaction with urinary calculi was investigated with various stone compositions, different incident fluences and number of applied pulses. Spectral-domain optical coherence tomography was used to image cross sections of ablation craters on the surface of urinary calculi. Our results indicate that femtosecond laser pulses can ablate various calculi compositions. Crater diameter and depth varies from tens of microns to several hundred microns when up to 1000 pulses were ...

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    13. Effect on blood glucose monitoring of skin pressure exerted by an optical coherence tomography probe

      Veronika V. Sapozhnikova, Roman V. Kuranov, Inga Cicenaite et al. We proposed to use optical coherence tomography (OCT) for continuous noninvasive blood glucose monitoring, and recently we significantly improved the sensitivity of this technique. The accuracy of OCT glucose monitoring is limited by several factors, including variation of tissue pressure exerted by ... [J. Biomed. Opt. 13, 021112 (2008)] published Fri Apr 25, 2008.
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    1-14 of 14
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  2. Topics in the News

    1. (14 articles) Roman V. Kuranov
    2. (11 articles) University of Texas at Austin
    3. (11 articles) Thomas E. Milner
    4. (5 articles) University of Texas Health Science Center
    5. (3 articles) Biwei Yin
    6. (2 articles) Northwestern University
    7. (2 articles) Hao F. Zhang
    8. (2 articles) Tianyi Wang
    9. (2 articles) Volcano Corporation
    10. (2 articles) Zhejiang University
    11. (2 articles) Raju Poddar
    12. (1 articles) University of Texas Medical Branch
    13. (1 articles) Duke University
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    Gas-Cell Referenced Swept Source Phase Sensitive Optical Coherence Tomography Comparison of pulsed photothermal radiometry, optical coherence tomography and ultrasound for melanoma thickness measurement in PDMS tissue phantoms Depth-resolved blood oxygen saturation measurement by dual-wavelength photothermal (DWP) optical coherence tomography In vivo depth-resolved oxygen saturation by dual-wavelength photothermal (DWP) OCT Feature Of The Week 1/22/12: In vivo depth-resolved oxygen saturation by dual-wavelength photothermal (DWP) OCT. Dual-wavelength photothermal optical coherence tomography for blood oxygen saturation measurement Dual-wavelength photothermal optical coherence tomography for imaging microvasculature blood oxygen saturation Feature Of The Week 5/26/2013: University of Texas at Austin Investigates Dual-Wavelength Photothermal OCT for Imaging Microvasculature Blood Oxygen Saturation High performance OCTA enabled by combining features of shape, intensity, and complex decorrelation A Novel 3D Segmentation Approach for Extracting Retinal Layers from Optical Coherence Tomography Images Assessing the Outcomes of Focused Heating of the Skin by a Long-Pulsed 1064 nm Laser with an Integrated Scanner, Infrared Thermal Guidance, and Optical Coherence Tomography Albumin‐PEG‐Based Biomaterial for Laser‐Tissue Soldering and Its Real‐Time Monitoring With Swept‐Source Optical Coherence Tomography