1. University of Tsukuba

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    1. Mentioned In 126 Articles

    2. Objective Evaluation of Functionality of Filtering Bleb Based on Polarization-Sensitive Optical Coherence Tomography

      Objective Evaluation of Functionality of Filtering Bleb Based on Polarization-Sensitive Optical Coherence Tomography
      Purpose : The fibrosis score is a new diagnostic score that we have developed to evaluate the function of bleb structures after glaucoma filtration surgery using polarization-sensitive optical coherence tomography (PS-OCT). This study aims to assess the efficacy of the fibrosis score in discriminating nonfunctional from the functional blebs. Methods : A total of 20 patients who had undergone glaucoma filtration surgery were imaged at different time periods after surgery using PS-OCT ...
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    3. Eye motion corrected OCT imaging with Lissajous scan pattern

      Eye motion corrected OCT imaging with Lissajous scan pattern
      Ophthalmic optical coherence tomography (OCT) is a powerful tool which provides high resolution three dimensional (3D) volumetric image of human retina. However, the measurement data of OCT suffer motion artifact due to the involuntary eye motion during data acquisition. To eliminate this motion artifact and provide the true shape of retinal image, an eye motion corrected OCT imaging method based on Lissajous scan pattern is proposed in this paper. In ...
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    4. Quantitative optical coherence tomography by maximum a-posteriori estimation of signal intensity

      Quantitative optical coherence tomography by maximum a-posteriori estimation of signal intensity
      A maximum a-posteriori (MAP) estimator for signal amplitude of optical coherence tomography (OCT) is presented. This estimator provides an accurate and low bias estimation of the correct OCT signal amplitude even at very low signal-tonoise ratios. As a result, contrast improvement of retinal OCT images is demonstrated. In addition, this estimation method allows for an estimation reliability to be calculated. By combining the MAP estimator with a previously demonstrated attenuation ...
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    5. Noise-immune complex correlation for vasculature imaging based on standard and Jones-matrix optical coherence tomography

      Noise-immune complex correlation for vasculature imaging based on standard and Jones-matrix optical coherence tomography
      A new optical coherence angiography (OCA) method, called correlation mapping OCA (cmOCA), is presented by using the SNR-corrected complex correlation. An SNR-correction theory for the complex correlation calculation is presented. The method also integrates a motion-artifact-removal method for the sample motion induced decorrelation artifact. The theory is further extended to compute more reliable correlation by using multi- channel OCT systems, such as Jones-matrix OCT. The high contrast vasculature imaging of ...
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    6. Quantitative polarization and flow evaluation of choroid and sclera by multifunctional Jones matrix optical coherence tomography

      Quantitative polarization and flow evaluation of choroid and sclera by multifunctional Jones matrix optical coherence tomography
      Quantitative evaluation of optical properties of choroid and sclera are performed by multifunctional optical coherence tomography. Five normal eyes, five glaucoma eyes and one choroidal atrophy eye are examined. The refractive error was found to be correlated with choroidal birefringence, polarization uniformity, and flow in addition to scleral birefringence among normal eyes. The significant differences were observed between the normal and the glaucoma eyes, as for choroidal polarization uniformity, flow ...
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    7. Three-dimensional multifunctional optical coherence tomography for skin imaging

      Three-dimensional multifunctional optical coherence tomography for skin imaging
      Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by ...
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    8. Maximum a posteriori estimator for high-contrast image composition of optical coherence tomography

      Maximum a posteriori estimator for high-contrast image composition of optical coherence tomography
      A quantitative signal amplitude estimator for optical coherence tomography (OCT) is presented. It is based on a statistical model of OCT signal and noise, using a Bayesian maximum a posteriori (MAP) estimation framework. Multiple OCT images are used for estimation, similar to the widely utilized intensity averaging method. The estimator is less biased especially at low-intensity regions, where intensity averaging approaches the noise power and hence is biased. The estimator ...
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    9. Birefringence imaging of posterior eye by multi-functional Jones matrix optical coherence tomography

      Birefringence imaging of posterior eye by multi-functional Jones matrix optical coherence tomography
      A clinical grade prototype of posterior multifunctional Jones matrix optical coherence tomography (JM-OCT) is presented. This JM-OCT visualized depth-localized birefringence in addition to conventional cumulative phase retardation imaging through local Jones matrix analysis. In addition, it simultaneously provides a sensitivity enhanced scattering OCT, a quantitative polarization uniformity contrast, and OCT-based angiography. The probe beam is at 1- m wavelength band. The measurement speed and the depth-resolution were 100,000 A-lines ...
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    10. Noninvasive vascular imaging of ruptured retinal arterial macroaneurysms by Doppler optical coherence tomography

      Noninvasive vascular imaging of ruptured retinal arterial macroaneurysms by Doppler optical coherence tomography
      Background To describe Doppler optical coherence tomography (OCT) imaging of ruptured retinal arterial macroaneurysms (RAMs). Methods Four eyes of four patients with ruptured RAMs were prospectively studied. Vascular imaging was obtained using swept-source Doppler OCT, and compared with indocyanine green angiography images. Results En face projection of Doppler OCT images clearly showed RAMs at the corresponding locations of lesions in the indocyanine green angiography images. In Doppler OCT images, RAMs ...
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    11. Noninvasive Vascular Imaging of Polypoidal Choroidal Vasculopathy by Doppler Optical Coherence Tomography

      Noninvasive Vascular Imaging of Polypoidal Choroidal Vasculopathy by Doppler Optical Coherence Tomography
      Purpose. To noninvasively investigate the vascular architecture of polypoidal lesions in polypoidal choroidal vasculopathy (PCV) using Doppler optical coherence tomography (OCT), and to evaluate the clinical usefulness of Doppler OCT for the assessment of therapeutic effects in PCV. Methods. Fifteen eyes of 15 patients with treatment-nave PCV were prospectively studied. Vascular imaging was obtained using 1060-nm swept-source Doppler OCT, and compared with indocyanine green angiography (ICGA) images. The therapeutic effect ...
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    12. Repeatability of Corneal Phase Retardation Measurements by Polarization-Sensitive Optical Coherence Tomography

      Repeatability of Corneal Phase Retardation Measurements by Polarization-Sensitive Optical Coherence Tomography
      Purpose. Polarization-sensitive optical coherence tomography (PS-OCT) can evaluate internal tissue structures of the cornea, such as collagen fibers, by phase retardation measurement. In this study, we assessed the repeatability of corneal phase retardation measurements using anterior segment PS-OCT. Methods. A total of 173 eyes of 173 patients were measured using PS-OCT. In total, 58 eyes of young subjects with normal corneas, 28 eyes of old subjects with normal corneas, 26 ...
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    13. Doppler Optical Coherence Tomography Imaging of Feeder Vessels in Exudative Macular Disease

      Doppler Optical Coherence Tomography Imaging of Feeder Vessels in Exudative Macular Disease
      We evaluated the three-dimensional vascular architecture of feeder vessels in exudative macular disease. A case of polypoidal choroidal vasculopathy with choroidal neovascularization was examined with Doppler optical coherence tomography (OCT), and the three-dimensional architecture of the feeder vessels could be clearly visualized in the Doppler OCT angiography image, showing the site of growth of the feeder vessels passing through Bruchs membrane. Together, the results demonstrated in this case report that ...
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    14. Depth-Resolved Dynamics of Aceto-Whitening in Rabbit Cornea Studied by 1300 nm Optical Coherence Tomography

      Depth-Resolved Dynamics of Aceto-Whitening in Rabbit Cornea Studied by 1300 nm Optical Coherence Tomography
      In many developing parts of the world, colposcopy supplemented by aceto-whitening remains the most widespread means of reliably diagnosing cervical dysplasia, potentially leading to cervical cancer. The use of aceto-whitening to enhance detection rates for Barretts esophagus is also emerging in recent years. Here we quantitatively study the aceto-whitening phenomenon using 1300 nm optical coherence tomography. By exposing a simple epithelial tissue model (excised rabbit cornea) to 0.5 M ...
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  2. About University of Tsukuba

    University of Tsukuba

    University of Tsukuba is located in the city of Tsukuba. The university is ranked one of the top Asian universities in the "Academic Ranking of World Universities" and is ranked 102-150 in the world. The University of Tsukuba has had several Nobel Prize winners so far, namely Leo Esaki, Hideki Shirakawa and Sin-Itiro Tomonaga, which is extremely rare among universities in Asia, where there have been fewer Nobel laureates than in European and American universities. 

    The Computational Optics Group (COG)  at the University of Tsukuba formed in 1999 as a division of applied optics laboratory, institute of applied physics, university of Tsukuba. On that moment we were not COG but spatio-temporal optics group, and our main research subject was spatio-temporal optical computing.   In 2000, we started a optical measurement project using spatio-temporal optical computing technologies, and in 2002, we changed our direction to more computationally.   Since 2002, our main research interest is computer assisted optical measurment. We are trying to introduce computational technologies into optical measurement.  Since 2007, we are an independent research group and no longer a part of Applied Optics Laboratory of University of Tsukuba.