1. Articles from Raju Poddar

    1-12 of 12
    1. Investigation of Puccinia triticina contagion on wheat leaves using swept source optical coherence tomography

      Investigation of Puccinia triticina contagion on wheat leaves using swept source optical coherence tomography

      We present an investigation on applicability of swept-source optical coherence tomography (SSOCT) to examine the internal structures of plant leaves. This study helps to identify the growth and spread of the leaf rust disease in leaves of wheat plants, caused by Puccinia triticina . The epidermal cell layer and parenchyma cell layer of the acquired OCT images are correlated with the histological images to show distinctive leaf morphological boundaries. In the OCT images, the thickness of the parenchyma cell layer in healthy and infected samples are compared and analyzed. Accurate morphological and quantitative information are obtained with our developed system for ...

      Read Full Article
      Mentions: Raju Poddar
    2. Zinc oxide nanoparticles (ZnONPs) as contrast agent for imaging of animal tissue using swept source optical coherence tomography (SSOCT)

      Zinc oxide nanoparticles (ZnONPs) as contrast agent for imaging of animal tissue using swept source optical coherence tomography (SSOCT)

      We present applicability of ZnO nanoparticles (ZnONPs) as a potential contrast agent for Optical Coherence Tomography (OCT) imaging. A 1064 nm laser source was used in a swept source configuration capable of a scanning rate of 100 kHz (100,000 A-lines/s). Swept Source Optical Coherence Tomography (SSOCT) is a variation of OCT, offering greater scan rates, higher resolution and signal-to-noise ratios. To enhance the contrast of an OCT frame, ZnO nanoparticles were used as an exogeneous contrast agent, which were fabricated using zinc acetic acid derivation and oxalic acid via precipitation. The particles were characterized using UV–vis Spectroscopy ...

      Read Full Article
      Mentions: Raju Poddar
    3. Imaging of human finger nail-fold with MHz A-scan rate swept source optical coherence tomography

      Imaging of human finger nail-fold with MHz A-scan rate swept source optical coherence tomography

      We present a non-invasive three-dimensional depth-resolved micro-structure and micro-vasculature imaging of a human fingernail-fold with a swept-source optical coherence tomography (ssOCT) system at a 1064 nm center wavelength. A phase variance OCT angiography (OCTA) method was implemented for motion contrast OCT imaging. A Fourier-domain mode-locked light source with an A-scan rate of 1.7 MHz (1 700 000 A-scans s −1 ) was utilized for imaging. The experimental setup demonstrates OCT and OCTA imaging with an area of ~5 mm   ×   5 mm (within the Nyquist limit). Details of the ssOCTA system such as system parameters, scanning protocols, acquisition time, challenges, and ...

      Read Full Article
      Mentions: Raju Poddar
    4. TiO2 nanoparticles as exogenous contrast agent for 1 µm swept source optical coherence tomography: an in vitro study

      TiO2 nanoparticles as exogenous contrast agent for 1 µm swept source optical coherence tomography: an in vitro study

      Optical coherence tomography (OCT) is a rapidly evolving, robust technology that has profoundly changed the practice of medical imaging. Swept source OCT (SSOCT) combines the standard time domain and the spatially encoded frequency domain OCT. We have employed a high-speed SSOCT system that utilizes a swept source laser with an A-scan rate of 100 kHz and a central wavelength of 1060 nm for the imaging of the tissue. SSOCT at 1060 nm allows for high penetration in the tissue. TiO 2 nanoparticles (NPs) are mostly used for various experimental purposes as an exogenous imaging contrast agent. The in vitro imaging ...

      Read Full Article
      Mentions: Raju Poddar
    5. Silver nanoparticles (AgNPs) as a contrast agent for imaging of animal tissue using swept-source optical coherence tomography (SSOCT)

      Silver nanoparticles (AgNPs) as a contrast agent for imaging of animal tissue using swept-source optical coherence tomography (SSOCT)

      We present noninvasive three-dimensional depth-resolved imaging of animal tissue with a swept-source optical coherence tomography system at 1064 nm center wavelength and silver nanoparticles (AgNPs) as a potential contrast agent. A swept-source laser light source is used to enable an imaging rate of 100 kHz (100 000 A-scans s −1 ). Swept-source optical coherence tomography is a new variant of the optical coherence tomography (OCT) technique, offering unique advantages in terms of sensitivity, reduction of motion artifacts, etc. To enhance the contrast of an OCT image, AgNPs are utilized as an exogeneous contrast agent. AgNPs are synthesized using a modified Tollens ...

      Read Full Article
      Mentions: Raju Poddar
    6. Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate

      Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate

      We present noninvasive, three-dimensional, depth-resolved imaging of human retinal and choroidal blood circulation with a swept-source optical coherence tomography (OCT) system at 1065-nm center wavelength. Motion contrast OCT imaging was performed with the phase-variance OCT angiography method. A Fourier-domain mode-locked light source was used to enable an imaging rate of 1.7 MHz. We experimentally demonstrate the challenges and advantages of wide-field OCT angiography (OCTA). In the discussion, we consider acquisition time, scanning area, scanning density, and their influence on visualization of selected features of the retinal and choroidal vascular networks. The OCTA imaging was performed with a field of ...

      Read Full Article
    7. Implementation of the swept source optical coherence tomography (SSOCT) system with a statistical method to analyze optical properties of turbid media

      Implementation of the swept source optical coherence tomography (SSOCT) system with a statistical method to analyze optical properties of turbid media

      We present a spectroscopic OCT (sOCT) system to extract spectroscopic properties of turbid media using principle component analysis (PCA) and swept source optical coherence tomography (SSOCT). Extracted results are well comparable with the standard photo spectrometer technique. This system has potential for real time measurement of blood oxygen saturation and monitoring of relative concentration for other metabolic compounds inside human body.

      Read Full Article
      Mentions: Raju Poddar
    8. In vivo volumetric depth-resolved vasculature imaging of human limbus and sclera with 1μm swept source phase-variance optical coherence angiography

      In vivo volumetric depth-resolved vasculature imaging of human limbus and sclera with 1μm swept source phase-variance optical coherence angiography

      We present in vivo volumetric depth-resolved vasculature images of the anterior segment of the human eye acquired with phase-variance based motion contrast using a high-speed (100 kHz, 10 5 A-scans/s) swept source optical coherence tomography system (SSOCT). High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. The human corneo–scleral junction and sclera were imaged with swept source phase-variance optical coherence angiography and compared with slit lamp images from the same eyes of normal subjects. Different features of the rich vascular system in the conjunctiva and episclera were visualized and described. This system ...

      Read Full Article
    9. In vivo imaging of human vasculature in the chorioretinal complex using phase-variance contrast method with phase-stabilized 1-μm swept-source optical coherence tomography

      In vivo imaging of human vasculature in the chorioretinal complex using phase-variance contrast method with phase-stabilized 1-μm swept-source optical coherence tomography

      We present a noninvasive phase-variance (pv)–based motion contrast method for depth-resolved imaging of the human chorioretinal complex microcirculation with a newly developed phase-stabilized high speed (100-kHz A-scans/s) 1 - μ m swept-source optical coherence tomography (SSOCT) system. Compared to our previous spectral-domain (spectrometer based) pv-spectral domain OCT (SDOCT) system, this system has the advantages of higher sensitivity, reduced fringe wash-out for high blood flow speeds and deeper penetration in choroid. High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. This process does not require additional calibration hardware and complex numerical procedures. Our phase stabilization ...

      Read Full Article
    10. In vitro 3D anterior segment imaging in lamb eye with extended depth range swept source optical coherence tomography

      In vitro 3D anterior segment imaging in lamb eye with extended depth range swept source optical coherence tomography

      A complex conjugate resolved, extended depth range, high speed 1 μm swept-source optical coherence tomography (SSOCT) provides a dense three-dimensional (3-D) imaging of the entire anterior segment of eye. SSOCT system utilizes “coherence revival” characteristics of the light source (external cavity tunable laser, ECTL), which is automatically phase modulated. We describe implementation of this with a common swept laser with built-in k-clock to allow imaging in high depth range, 10.5 mm in air, without any external MZI clock. The system is capable of generating long depth range without any modulators or frequency shifter. Most of the commercially available OCT ...

      Read Full Article
      Mentions: Raju Poddar
    11. Improved in vivo imaging of human blood circulation in the chorioretinal complex using phase variance method with new phase stabilized 1 μm swept-source optical coherence tomography (pv-SSOCT)

      Improved in vivo imaging of human blood circulation in the chorioretinal complex using phase variance method with new phase stabilized 1 μm swept-source optical coherence tomography (pv-SSOCT)

      We demonstrate the feasibility of our newly developed phase stabilized high-speed (100 kHz A-scans/s) 1 μm sweptsource optical coherence tomography (SSOCT) system with the phase-variance based motion contrast method for visualization of human chorioretinal complex microcirculation. Compared to our previously reported spectral domain (spectrometer based) phase-variance (pv)-SDOCT system it has advantages of higher sensitivity, reduced fringe washout for high blood flow speeds and deeper penetration in choroid. High phase stability SSOCT imaging was achieved by using a computationally efficient phase stabilization approach. This process does not require additional calibration hardware and complex numerical procedures. Our phase stabilization method ...

      Read Full Article
    12. Application of full range swept source optical coherence tomography for imaging of the anterior eye segment in patients with type I Boston Keratoprosthesis

      Application of full range swept source optical coherence tomography for imaging of the anterior eye segment in patients with type I Boston Keratoprosthesis

      We present a high-speed complex conjugate resolved 1 μm swept source optical coherence tomography [SS-OCT] system using coherence revival of the light source for clinical imaging of the anterior segment of the eye. High-speed of 100,000 A-scans/sec and 1 μm imaging window of OCT permits dense 3D imaging of the anterior segment, minimizing the influence of motion artifacts and deep penetration of images for topographic analysis. The swept laser performance with internal clocking was adapted to achieve extended imaging depth requirements. The feasibility of our instrument for visualization of the anterior segment of patients with the Boston Keratoprosthesis ...

      Read Full Article
    1-12 of 12
  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. (12 articles) Raju Poddar
    2. (5 articles) UC Davis
    3. (5 articles) John S. Werner
    4. (4 articles) Robert J. Zawadzki
    5. (2 articles) Dae Yu Kim
    6. (1 articles) California Institute of Technology
    7. (1 articles) Daniel M. Schwartz
    8. (1 articles) Iwona Gorczynska
    9. (1 articles) University of Tübingen
    10. (1 articles) University of Western Australia
    11. (1 articles) Tufts University
    12. (1 articles) University of Michigan
    13. (1 articles) FDA
    14. (1 articles) Barry Cense
    15. (1 articles) Jerome Sherman
    16. (1 articles) Optovue
    17. (1 articles) Carl Zeiss Meditec
    18. (1 articles) Optos
  3. Popular Articles

  4. Picture Gallery

    Application of full range swept source optical coherence tomography for imaging of the anterior eye segment in patients with type I Boston Keratoprosthesis Improved in vivo imaging of human blood circulation in the chorioretinal complex using phase variance method with new phase stabilized 1 μm swept-source optical coherence tomography (pv-SSOCT) In vitro 3D anterior segment imaging in lamb eye with extended depth range swept source optical coherence tomography In vivo imaging of human vasculature in the chorioretinal complex using phase-variance contrast method with phase-stabilized 1-μm swept-source optical coherence tomography In vivo volumetric depth-resolved vasculature imaging of human limbus and sclera with 1μm swept source phase-variance optical coherence angiography Implementation of the swept source optical coherence tomography (SSOCT) system with a statistical method to analyze optical properties of turbid media Challenges and advantages in wide-field optical coherence tomography angiography imaging of the human retinal and choroidal vasculature at 1.7-MHz A-scan rate Silver nanoparticles (AgNPs) as a contrast agent for imaging of animal tissue using swept-source optical coherence tomography (SSOCT) TiO2 nanoparticles as exogenous contrast agent for 1 µm swept source optical coherence tomography: an in vitro study Imaging of human finger nail-fold with MHz A-scan rate swept source optical coherence tomography Phenotyping of Mouse Models with OCT Retinal imaging with optical coherence tomography and low‐loss adaptive optics using a 2.8‐mm beam size