1. University of Tsukuba

    0 Comments Leave a Comment

    1-15 of 157 1 2 3 4 ... 9 10 11 »
    1. Mentioned In 157 Articles

    2. Jones matrix OCT system and program for carrying out image processing on measured data obtained by said OCT

      Jones matrix OCT system and program for carrying out image processing on measured data obtained by said OCT
      A Jones matrix OCT offers improved image stability, image quality, and depth range of image, wherein light from a wavelength-scanning light source is split into two optical paths, and a reference arm is provided along one optical path, while a probe arm that irradiates and reflects light onto the measuring target to generate object light is provided along the other optical path. The probe arm has a polarization delay unit ...
      Read Full Article
    3. Polarization-sensitive optical coherence elastography

      Polarization-sensitive optical coherence elastography
      Polarization-sensitive optical coherence elastography (PS-OCE) is developed for improved tissue discrimination. It integrates Jones matrix-based PS-optical coherence tomography (PS-OCT) with compression OCE. The method simultaneously measures the OCT intensity, attenuation coefficient, birefringence, and microstructural deformation (MSD) induced by tissue compression. Ex vivo porcine aorta and esophagus tissues were investigated by PS-OCE and histological imaging. The tissue properties measured by PS-OCE are shown as cross-sectional images and a three-dimensional (3-D) depth-trajectory ...
      Read Full Article
    4. Evaluation of Retinal Pigment Epithelium Layer Change in Vogt-Koyanagi-Harada Disease With Multicontrast Optical Coherence Tomography

      Evaluation of Retinal Pigment Epithelium Layer Change in Vogt-Koyanagi-Harada Disease With Multicontrast Optical Coherence Tomography
      Purpose : Clinical evaluation of retinal pigment epithelium (RPE) change is important for the therapeutic management of chronic Vogt-Koyanagi-Harada (VKH) disease. We evaluated long-term change in the RPE layer in VKH disease, using near-infrared (NIR; 817 nm) images and autofluorescence images at 488 nm (short-wavelength [SW]-AF) and 785 nm (NIR-AF), and compared those images with images from multicontrast optical coherence tomography (MC-OCT). MC-OCT is capable of simultaneous measurement of OCT ...
      Read Full Article
    5. Multi-scale and -contrast sensorless adaptive optics optical coherence tomography

      Multi-scale and -contrast sensorless adaptive optics optical coherence tomography
      Background: The roles of the retinal microvasculature and the retinal pigment epithelium (RPE) in maintaining the health and metabolic activity of the retina lend great clinical value to their high-resolution visualization. Methods: By integrating polarization diversity detection (PDD) into multi-scale and -contrast sensorless adaptive optics optical coherence tomography (MSC-SAO-OCT), we have developed a novel multi-contrast SAO OCT system for imaging pigment in the RPE as well as flow in the ...
      Read Full Article
    6. Optical coherence tomography apparatus for selectively visualizing and analyzing vascular network of choroidal layer, and image-processing program and image-processing method for the same

      Optical coherence tomography apparatus for selectively visualizing and analyzing vascular network of choroidal layer, and image-processing program and image-processing method for the same
      From OCT-measured data, only the image data of the choroidal vascular network present in the layer of the choroidal layer is selectively extracted, thereby accurately obtaining the thickness of the choroidal vessels and thickness of the choroidal vascular network from the image data, to allow for quantitative evaluation of the choroidal vascular network. The optical coherence tomography apparatus has an optical coherence tomography device, and a computer that processes the ...
      Read Full Article
    7. Clinical prototype of pigment and flow imaging optical coherence tomography for posterior eye investigation

      Clinical prototype of pigment and flow imaging optical coherence tomography for posterior eye investigation
      Measurements of the randomness of polarization (RP) obtained using polarization-sensitive optical coherence tomography (PS-OCT) are applied in several applications, and RP is attractive for posterior eye imaging. The addition of RP without retardation requires a minimal extension to standard OCT; therefore, we developed a prototype OCT system with a simplified scheme for RP measurement. A compact polarization-diversity receiver module is the only required hardware extension to a standard OCT system ...
      Read Full Article
    8. Machine-learning based segmentation of the optic nerve head using multi-contrast Jones matrix optical coherence tomography with semi-automatic training dataset generation

      Machine-learning based segmentation of the optic nerve head using multi-contrast Jones matrix optical coherence tomography with semi-automatic training dataset generation
      A pixel-by-pixel tissue classification framework using multiple contrasts obtained by Jones matrix optical coherence tomography (JM-OCT) is demonstrated. The JM-OCT is an extension of OCT that provides OCT, OCT angiography, birefringence tomography, degree-of-polarization uniformity tomography, and attenuation coefficient tomography, simultaneously. The classification framework consists of feature engineering, k -means clustering that generates a training dataset, training of a tissue classifier using the generated training dataset, and tissue classification by the ...
      Read Full Article
    9. Pixel-wise segmentation of severely pathologic retinal pigment epithelium and choroidal stroma using multi-contrast Jones matrix optical coherence tomography

      Pixel-wise segmentation of severely pathologic retinal pigment epithelium and choroidal stroma using multi-contrast Jones matrix optical coherence tomography
      Tissue segmentation of retinal optical coherence tomography (OCT) is widely used in ophthalmic diagnosis. However, its performance in severe pathologic cases is still insufficient. We propose a pixel-wise segmentation method that uses the multi-contrast measurement capability of Jones matrix OCT (JM-OCT). This method is applicable to both normal and pathologic retinal pigment epithelium (RPE) and choroidal stroma. In this method, features, which are sensitive to specific tissues of interest, are ...
      Read Full Article
    10. Comparison of intensity, phase retardation, and local birefringence images for filtering blebs using polarization-sensitive optical coherence tomography

      Comparison of intensity, phase retardation, and local birefringence images for filtering blebs using polarization-sensitive optical coherence tomography
      Polarization-sensitive optical coherence tomography (PS-OCT) allows the recording of depth-resolved polarimetric measurements. It has been reported that phase retardation and local birefringence images can noninvasively detect fibrotic area in blebs after glaucoma surgery. Evaluation of scar fibrosis in blebs is important not only for predicting bleb function, but also for planning revision trabeculectomy. Herein, we characterize the intensity, phase retardation, and local birefringence images of blebs using PS-OCT. A total ...
      Read Full Article
    11. Simultaneous tissue birefringence and deformation measurement by polarization sensitive optical coherence elastography with active compression

      Simultaneous tissue birefringence and deformation measurement by polarization sensitive optical coherence elastography with active compression
      Polarization sensitive optical coherence tomography (PS-OCT) measures tissue birefringence, while optical coherence elastography (OCE) reveals the mechanical property of the tissue. Since both birefringence and mechanical properties are associated with tissue microstructures such as collagen, simultaneous PS-OCT and OCE measurement will provide useful insight for the tissue microstructures. In this paper, we present a combined PS-OCT and OCE technique. The PS-OCT is based on Jones matrix OCT theory. It measures ...
      Read Full Article
    12. Objective evaluation of choroidal melanin contents with polarization-sensitive optical coherence tomography

      Objective evaluation of choroidal melanin contents with polarization-sensitive optical coherence tomography
      We non-invasively evaluated choroidal melanin contents in human eyes with PS-OCT. We calculated the percentage area of low DOPU in the choroidal interstitial stroma for Vogt-Koyanagi- Harada disease with sunset glow fundus, without sunset glow fundus, control group and tessellated fundus with high myopia. The mean percentage area of low DOPU in the sunset group was significantly lower than the other groups. PS-OCT provides an in vivo objective evaluation of ...
      Read Full Article
    13. Eye-motion-corrected optical coherence tomography angiography using Lissajous scanning

      Eye-motion-corrected optical coherence tomography angiography using Lissajous scanning
      To correct eye motion artifacts in en face optical coherence tomography angiography (OCT-A) images, a Lissajous scanning method with subsequent software-based motion correction is proposed. The standard Lissajous scanning pattern is modified to be compatible with OCT-A and a corresponding motion correction algorithm is designed. The effectiveness of our method was demonstrated by comparing en face OCT-A images with and without motion correction. The method was further validated by comparing ...
      Read Full Article
    14. Generation and optimization of superpixels as image processing kernels for Jones matrix optical coherence tomography

      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 ...
      Read Full Article
    15. 1-15 of 157 1 2 3 4 ... 9 10 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. 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.