1. Articles from K. Divakar Rao

    1-11 of 11
    1. Investigation of sputtering target re-deposits by Optical Coherence Tomography and Grazing Incident X-ray Diffraction

      Investigation of sputtering target re-deposits by Optical Coherence Tomography and Grazing Incident X-ray Diffraction

      The sputtering target re-deposit grown by cumulative sputtering has been investigated in this work by studying both fresh and rigorously sputtered zirconium oxide target by Fourier Domain Optical Coherence Tomography (FDOCT), a depth resolved optical imaging modality. The Optical Coherence Tomography (OCT) depth profiles have further been analyzed to extract optical attenuation coefficient of sputtered target surface as well as fresh target surface. Re-deposited sputtered target surface shows larger optical attenuation coefficient in the range of 1.5-4.4 mm −1 as opposed to that of 1.1 mm −1 for fresh ZrO 2 target. The same sputtered target surfaces ...

      Read Full Article
      Mentions: K. Divakar Rao
    2. Perspectives of optical coherence tomography imaging and Raman spectroscopy in cancer diagnosis

      Perspectives of optical coherence tomography imaging and Raman spectroscopy in cancer diagnosis

      Biomedical optical imaging and optical spectroscopy are rapidly emerging as strong contenders for non-invasive optical biopsy. In biomedical imaging, Optical Coherence Tomography (OCT) is an established imaging modality for non-contact depth-resolved three-dimensional imaging with micrometer scale resolution. OCT provides label-free micro-structural morphological information of the tissue. Raman spectroscopy is a complementary tool for obtaining molecular-specific information for diagnosis. This article provides a brief overview of the underlying principles of OCT and Raman spectroscopy, their instrumentation with representative latest developments in cancer diagnosis. 

      Read Full Article
      Mentions: K. Divakar Rao
    3. Optical coherence tomography for shape and radius of curvature measurements of deeply curved machined metallic surfaces: a comparison with two-beam laser interferometry

      Optical coherence tomography for shape and radius of curvature measurements of deeply curved machined metallic surfaces: a comparison with two-beam laser interferometry

      An application of optical coherence tomography (OCT) for measuring shape and the radius of curvature of deeply curved metallic surfaces in precision mechanical components is demonstrated. Measurements carried out by OCT technique on concave and convex hemispherical metallic surfaces generated by diamond turning process is presented. The technique is compared with a two-beam laser interferometric method for determinations of shape errors and radius of curvature. It is shown that OCT is a useful tool for three-dimensional shape determinations for deeply curved surfaces such as hemispheres and has advantages over two-beam laser interferometric method.

      Read Full Article
      Mentions: K. Divakar Rao
    4. Depth-sensitive Raman spectroscopy combined with optical coherence tomography for layered tissue analysis

      Depth-sensitive Raman spectroscopy combined with optical coherence tomography for layered tissue analysis

      Complete characterization of a layered tissue requires probing both the biochemical and the morphological information from its different layers at various depths. We report the development of a combined Raman spectroscopy (RS) and optical coherence tomography (OCT) system that is capable of measuring depth-sensitive Raman signal from the tissue layers imaged by the OCT. The sample arm of a real-time time-domain OCT system was modified to allow for co-alignment of the OCT with the Raman probe beam. The depth sensitivity of Raman was obtained by incorporating confocal Raman configuration that minimized out-of-focus Raman scattered light. The system was first validated ...

      Read Full Article
    5. Feature Of The Week 11/13/11: OCT Used for Analysis of Developmental Defects in Zebrafish Embryos

      Feature Of The Week 11/13/11: OCT Used for Analysis of Developmental Defects in Zebrafish Embryos
      It is known that consumption of alcohol during pregnancy can lead to several disorders ranging from Fetal Alcohol Syndrome (FAS), alcohol related birth defects, and neuro developmental defects. Zebrafish is a popular model to understand the mechanisms of embryonic ethanol exposure generated disorders. To track these developmental defects, a noninvasive imaging technique like OCT could be useful, as it provides high-resolution cross-sectional images of tissues. Further, current high-speed OCT technology enables repeated imaging studies to be performed on the same specimen and can be useful for imaging the internal anatomical structures such as eye.Researchers at Raja Ramanna Centre for ...
      Read Full Article
    6. Imaging of human breast tissue using polarization sensitive optical coherence tomography

      Imaging of human breast tissue using polarization sensitive optical coherence tomography
      Abstract  We report a study on the use of polarization sensitive optical coherence tomography (PSOCT) for discriminating malignant (invasive ductal carcinoma), benign (fibroadenoma) and normal (adipocytes) breast tissue sites. The results show that while conventional OCT, that utilizes only the intensity of light back-scattered from tissue microstructures, is able to discriminate breast tissues as normal (adipocytes) and abnormal (malignant and benign) tissues, PS-OCT helps in discriminating between malignant and benign tissue sites also. The estimated values of birefringence obtained from the PSOCT imaging show that benign breast tissue samples have significantly higher birefringence as compared to the malignant tissue samples.
      Read Full Article
    7. Noninvasive imaging of ethanol-induced developmental defects in zebrafish embryos using optical coherence tomography

      Noninvasive imaging of ethanol-induced developmental defects in zebrafish embryos using optical coherence tomography
      In this article, we report the use of optical coherence tomography for noninvasive cross-sectional real-time imaging of ethanol-induced developmental defects in zebrafish embryos larvae. For ethanol concentration of over 300 mM, developmental defects of eye (shrinkage and retinal abnormalities), malformation of the notochord and ataxia arising due to the toxic effects of ethanol were observed in OCT images from 3 days post fertilization onwards. The results suggest that OCT could be a valuable tool for noninvasive assessment of birth defects in small animal systems.
      Read Full Article
    8. Use of common path phase sensitive spectral domain optical coherence tomography for refractive index measurements

      Use of common path phase sensitive spectral domain optical coherence tomography for refractive index measurements
      We report the use of a common path phase sensitive spectral domain optical coherence tomography setup for the measurement of the refractive index (RI) of a biomimetic material (glucose solution in water having intralipid as the scattering medium) and a single biological cell (keratinocyte). The RI of glucose solutions could be measured with a precision of ∼0.00015, which corresponds to a precision of ∼2 nm in the optical path length measurement in our setup. The precision obtained in the measurement of the RI of a single keratinocyte cell was ∼0.0004.
      Read Full Article
    9. Feature Of The Week 4/11/10: Noninvasive Assessment of Healing of Bacteria Infected and Uninfected Wounds using Optical Coherence Tomography

      Feature Of The Week 4/11/10: Noninvasive Assessment of Healing of Bacteria Infected and Uninfected Wounds using Optical Coherence Tomography
      Feature Of The Week 4/11/10: Microbial infection is one of the major factors for the impairment of wound healing as the microbial toxins have a detrimental effect on collagen in the wounded tissue. Infected wounds can cause increased trauma, could severely compromise the overall health of an individual as well as increase the cost of treatment. To facilitate a faster healing of wounds it will be desirable if the signatures of microbial infection in wounds can be monitored non-invasively. OCT is an ideal non-invasive imaging technique for this purpose as it provides high-resolution cross-sectional images of tissues with ...
      Read Full Article
    10. Real-time in vivo imaging of adult Zebrafish brain using optical coherence tomography

      Real-time in vivo imaging of adult Zebrafish brain using optical coherence tomography

      We report noninvasive imaging of the brain of adult Zebrafish (Danio rerio) using real time optical coherence tomography (OCT) capable of acquiring cross sectional 2D OCT images @ 8 frames/sec. Anatomic features such as telencephalon, tectum opticum, eminentia Granularis and cerebellum were clearly resolved in the OCT images. A 3D model of Zebrafish brain was reconstructed, for the first time to our knowledge, using these 2D OCT images.

      Read Full Article
    11. Optical coherence tomography using a tapered single mode fiber tip

      Optical coherence tomography using a tapered single mode fiber tip
      We report the use of a chemically etched tapered single mode fiber tip for enhancing lateral resolution in optical coherence tomography (OCT). The important advantage of this approach is that high lateral resolution is achieved, without compromising the depth of imaging, as is the case with the use of high numerical aperture objectives. Use of the tapered tip in the sample arm of a single mode fiber based set-up allowed visualization of intracellular structures of Elodea densa plant leaf that could not be seen by the conventional OCT,
      Read Full Article
    1-11 of 11
  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. (11 articles) K. Divakar Rao
    2. (8 articles) Pradeep K. Gupta
    3. (7 articles) Raja Ramanna Centre for Advanced Technology
    4. (5 articles) Yogesh Verma
    5. (4 articles) Mrinalini Sharma
    6. (1 articles) Cardiff University
    7. (1 articles) Gwangju Institute of Science and Technology
    8. (1 articles) Khageswar Sahu
    9. (1 articles) Aneesh Alex
    10. (1 articles) University of Sydney
    11. (1 articles) University of Zurich
    12. (1 articles) UCSD
    13. (1 articles) University of Pittsburgh
    14. (1 articles) L V Prasad Eye Institute
    15. (1 articles) Giuseppe Querques
    16. (1 articles) Carl Zeiss Meditec
  3. Popular Articles

  4. Picture Gallery

    Real-time in vivo imaging of adult Zebrafish brain using optical coherence tomography Optical coherence tomography using a tapered single mode fiber tip Feature Of The Week 4/11/10: Noninvasive Assessment of Healing of Bacteria Infected and Uninfected Wounds using Optical Coherence Tomography Use of common path phase sensitive spectral domain optical coherence tomography for refractive index measurements Noninvasive imaging of ethanol-induced developmental defects in zebrafish embryos using optical coherence tomography Imaging of human breast tissue using polarization sensitive optical coherence tomography Feature Of The Week 11/13/11: OCT Used for Analysis of Developmental Defects in Zebrafish Embryos Depth-sensitive Raman spectroscopy combined with optical coherence tomography for layered tissue analysis Optical coherence tomography for shape and radius of curvature measurements of deeply curved machined metallic surfaces: a comparison with two-beam laser interferometry Perspectives of optical coherence tomography imaging and Raman spectroscopy in cancer diagnosis Optical coherence tomography features of neovascularization in proliferative diabetic retinopathy: a systematic review Retinal microvascular metrics in untreated essential hypertensives using optical coherence tomography angiography