1. University of Tsukuba

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    1. Mentioned In 143 Articles

    2. Generation and optimization of superpixels as image processing kernels for Jones matrix optical coherence tomography

      Explore OSA | OSA Publishing
      Generation and optimization of superpixels as image processing kernels for Jones matrix optical coherence tomography
      Jones matrix-based polarization sensitive optical coherence tomography (JM-OCT) simultaneously measures optical intensity, birefringence, degree of polarization uniformity, and OCT angiography. The statistics of the optical features in a local region, such as the local mean of the OCT intensity, are frequently used for image processing and the quantitative analysis of JM-OCT. Conventionally, local statistics have been computed with fixed-size rectangular kernels. However, this results in a trade-off between image sharpness ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    3. Introduction to the feature issue on the 25 year anniversary of optical coherence tomography

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      Introduction to the feature issue on the 25 year anniversary of optical coherence tomography
      This feature issue commemorates the approximately 25 year history of Optical Coherence Tomography (OCT), one of the most successful biophotonic technologies. While OCT has technological origins traceable to ultrafast laser development and fiber optic system test instrumentation of the 1980s, innovations in low coherence interferometry for optical ranging and imaging for biomedical applications in the U.S., Europe and Japan by the early 1990s led to coinage of the now ...
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      Mentions: Brett E. Bouma Johannes F. de Boer Joseph A. Izatt

    4. Multi-contrast imaging of human posterior eye by Jones matrix optical coherence tomography

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      Multi-contrast imaging of human posterior eye by Jones matrix optical coherence tomography
      A multi-contrast imaging of pathologic posterior eyes is demonstrated by Jones matrix optical coherence tomography (Jones matrix OCT). The Jones matrix OCT provides five tomographies, which includes scattering, local attenuation, birefringence, polarization uniformity, and optical coherence angiography, by a single scan. The hardware configuration, algorithms of the Jones matrix OCT as well as its application to ophthalmology is discussed.
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      Mentions: Yoshiaki Yasuno University of Tsukuba

    5. Noise-bias and polarization-artifact corrected optical coherence tomography by maximum a-posteriori intensity estimation

      Explore OSA | OSA Publishing Ophthalmology
      Noise-bias and polarization-artifact corrected optical coherence tomography by maximum a-posteriori intensity estimation
      We propose using maximum a-posteriori (MAP) estimation to improve the image signal-to-noise ratio (SNR) in polarization diversity (PD) optical coherence tomography. PD-detection removes polarization artifacts, which are common when imaging highly birefringent tissue or when using a flexible fiber catheter. However, dividing the probe power to two polarization detection channels inevitably reduces the SNR. Applying MAP estimation to PD-OCT allows for the removal of polarization artifacts while maintaining and improving ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno Masahiro Miura

    6. Three-dimensional eye motion correction by Lissajous scan optical coherence tomography

      Explore OSA | OSA Publishing Ophthalmology
      Three-dimensional eye motion correction by Lissajous scan optical coherence tomography
      A three-dimensional optical coherence tomography imaging method based on Lissajous scanning is presented. This method was designed to correct eye motion in OCT images. A Lissajous scanning pattern, which has a trajectory that frequently overlaps with itself, is adopted as the OCT scanning protocol to obtain measurement data. Eye motion artifacts are then corrected automatically by software. By comparing the images without and with motion correction, we show the effectiveness ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    7. Polarization sensitive optical coherence tomography – a review [Invited]

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      Polarization sensitive optical coherence tomography – a review [Invited]
      Optical coherence tomography (OCT) is now a well-established modality for high-resolution cross-sectional and three-dimensional imaging of transparent and translucent samples and tissues. Conventional, intensity based OCT, however, does not provide a tissue-specific contrast, causing an ambiguity with image interpretation in several cases. Polarization sensitive (PS) OCT draws advantage from the fact that several materials and tissues can change the lights polarization state, adding an additional contrast channel and providing quantitative ...
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      Mentions: Johannes F. de Boer Christoph K. Hitzenberger Yoshiaki Yasuno

    8. High contrast and polarization-artifact-free optical coherence tomography by maximum a-posteriori estimation

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      High contrast and polarization-artifact-free optical coherence tomography by maximum a-posteriori estimation
      We propose a maximum a-posteriori (MAP) intensity estimator to improve the image contrast of polarization diversity (PD)-OCT imaging to achieve high contrast polarization-artifact-free images. The MAP estimator compensates for the inevitable reduction of signal-to-noise ratio (SNR) in PD-OCT caused by the splitting of power into two polarization detection channels. It also has low noise-offset in low intensity regions such as the vitreous. This method is applied to posterior eye ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno Masahiro Miura

    9. Birefringence and vascular imaging of in vivo human skin by Jones-matrix optical coherence tomography

      Explore Conference Proceedings Dermatology
      Birefringence and vascular imaging of in vivo human skin by Jones-matrix optical coherence tomography
      A customized 1310-nm Jones-matrix optical coherence tomography (JM-OCT) for dermatological investigation was constructed and used for in vivo normal human skin tissue imaging. This system can simultaneously measure the threedimensional depth-resolved local birefringence, complex-correlation based OCT angiography (OCT-A), degree-ofpolarization- uniformity (DOPU) and scattering OCT intensity. By obtaining these optical properties of tissue, the morphology, vasculature, and collagen content of skin can be deduced and visualized. Structures in the deep layers ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    10. Motion-corrected en face optical coherence tomography angiography imaging based on the modified Lissajous scanning pattern

      Explore Conference Proceedings Ophthalmology
      Motion-corrected en face optical coherence tomography angiography imaging based on the modified Lissajous scanning pattern
      A motion - corrected en face optical coherence tomography angiography (OCT - A) imaging method is presented in this paper. This method was designed to correct eye motion artifacts in en face OCT - A images automatically using a software. A modified Lissajous scanning pattern, which is compatible with OCT - A, was adopted as the scanning protocol for the optical coherence tomography (OCT) machine to obtain the OCT - A data. The OCT - A ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    11. Evaluation of intraretinal migration of retinal pigment epithelial cells with Jones matrix optical coherence tomography

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      Evaluation of intraretinal migration of retinal pigment epithelial cells with Jones matrix optical coherence tomography
      We evaluated intraretinal RPE migration in AMD using multimodal imaging including polarimetric images. Depolarized light images were computed using a PS-SLO. M-DOPU was calculated using multifunctional Jones-matrix OCT. RPE migration was detected in 59 of 155 eyes. Focal similarities could be confirmed among en-face projection images of minimum M-DOPU, depolarized light images, and NIR-AF images.
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      Mentions: Shuichi Makita Yoshiaki Yasuno Masahiro Miura

    12. Three-dimensional multi-contrast imaging of in vivo human skin by Jones matrix optical coherence tomography

      Explore OSA | OSA Publishing Dermatology
      Three-dimensional multi-contrast imaging of in vivo human skin by Jones matrix optical coherence tomography
      A custom made dermatological Jones matrix optical coherence tomography (JM-OCT) is presented. It uses a passive-polarization-delay component based swept-source JM-OCT configuration, but is specially designed for in vivo human skin measurement. The center wavelength of its probe beam is 1310 nm and the A-line rate is 49.6 kHz. The JM-OCT is capable of simultaneously providing birefringence (local retardation) tomography, degree-of-polarization-uniformity tomography, complex-correlation-based optical coherence angiography, and conventional scattering OCT ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    13. Noise stochastic corrected maximum a posteriori estimator for birefringence imaging using polarization-sensitive optical coherence tomography

      Explore OSA | OSA Publishing
      Noise stochastic corrected maximum a posteriori estimator for birefringence imaging using polarization-sensitive optical coherence tomography
      This paper presents a noise-stochastic corrected maximum a posteriori estimator for birefringence imaging using Jones matrix optical coherence tomography. The estimator described in this paper is based on the relationship between probability distribution functions of the measured birefringence and the effective signal to noise ratio (ESNR) as well as the true birefringence and the true ESNR. The Monte Carlo method is used to numerically describe this relationship and adaptive 2D ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    14. Full-range ultrahigh-resolution spectral-domain optical coherence tomography in 1.7 µm wavelength region for deep-penetration and high-resolution imaging of turbid tissues

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      Full-range ultrahigh-resolution spectral-domain optical coherence tomography in 1.7 µm wavelength region for deep-penetration and high-resolution imaging of turbid tissues
      For the first time, we developed a full-range ultrahigh-resolution (UHR) spectral-domain optical coherence tomography (SD-OCT) technique working in the 1.7 m wavelength region. This technique allowed high-resolution, deep-tissue imaging. By using a supercontinuum source operating at a wavelength of 1.7 m, an axial resolution of 3.6 m in a tissue specimen was achieved. To enhance the imaging depth of UHR-SD-OCT, we performed full-range OCT imaging based on ...
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      Mentions: Shuichi Makita Yoshiaki Yasuno University of Tsukuba

    15. Quantitative Evaluation of Phase Retardation in Filtering Blebs Using Polarization-Sensitive Optical Coherence Tomography

      Explore IOVS Journal Ophthalmology
      Quantitative Evaluation of Phase Retardation in Filtering Blebs Using Polarization-Sensitive Optical Coherence Tomography
      Purpose : Polarization-sensitive optical coherence tomography (PS-OCT) can detect and evaluate scar fibrosis of the filtering blebs after glaucoma surgery. Although the change in phase retardation reportedly reflects bleb function, quantitative assessment of phase retardation in ocular tissues has not been conducted. We aimed to establish quantitative methods to investigate changes in phase retardation in the blebs after surgery using PS-OCT. Methods : Twenty-two blebs of 22 patients who had undergone glaucoma ...
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      Mentions: Yoshiaki Yasuno University of Tsukuba Deepa K. Kasaragod

    16. Program for correcting data measured by PS-OCT and PS-OCT system equipped with the program

      Explore uspto.gov Patents
      Program for correcting data measured by PS-OCT and PS-OCT system equipped with the program
      Data measured by PS-OCT is corrected in a non-linear manner to enhance the quantitative analysis capability of PS-OCT and permit accurate quantitative diagnosis, including diagnosis of disease stage of lesions, as a useful means for computer diagnosis. Even when retardation per PS-OCT 1 contains error and becomes noise and its distribution is not normal or symmetrical around the true value, measured data is converted using a distribution conversion function obtained ...
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      Mentions: Yoshiaki Yasuno University of Tsukuba
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  4. 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.

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