1. Articles from Toyohiko Yatagai

    1-13 of 13
    1. Ultra-high resolution spectral domain optical coherence tomography using supercontinuum light source

      Ultra-high resolution spectral domain optical coherence tomography using supercontinuum light source

      An ultra-high resolution spectral domain optical coherence tomography (SD-OCT) was developed using a cost-effective supercontinuum laser. A spectral filter consists of a dispersive prism, a cylindrical lens and a right-angle prism was built to transmit the wavelengths in range 680–940 nm to the OCT system. The SD-OCT has achieved 1.9 μm axial resolution and the sensitivity was estimated to be 91.5 dB. A zero-crossing fringes matching method which maps the wavelengths to the pixel indices of the spectrometer was proposed for the OCT spectral calibration. A double sided foam tape as a static sample and the tip ...

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    2. Three-dimensional retina image generation device

      Three-dimensional retina image generation device

      An optical coherence eye-fundus tomography device has a high resolution and a good operability, as well as be miniaturized and be produced at a low cost. The optical coherence eye-fundus tomography device includes: a light source unit which emits a source light beam; a reference-light unit which reflects a reference light beam; an inspection unit which illuminates an object with an object scanning light beam, reflected the object scanning light beam; and a detection unit which obtains a tomographic image of the object on the basis of the interference light beam produced by interfering the reflected reference light beam with ...

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    3. Developmental and morphological studies in Japanese medaka with ultra-high resolution optical coherence tomography

      Developmental and morphological studies in Japanese medaka with ultra-high resolution optical coherence tomography

      We propose ultra-high resolution optical coherence tomography to study the morphological development of internal organs in medaka fish in the post-embryonic stages at micrometer resolution. Different stages of Japanese medaka were imaged after hatching in vivo with an axial resolution of 2.8 µm in tissue. Various morphological structures and organs identified in the OCT images were then compared with the histology. Due to the medaka’s close resemblance to vertebrates, including humans, these morphological features play an important role in morphogenesis and can be used to study diseases that also occur in humans.

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      Mentions: Barry Cense
    4. Dental optical coherence tomograph

      Dental optical coherence tomograph
      A dental optical coherence tomography apparatus for measuring tissue in a stomatognathic region of a living body or an artificial composition in the stomatognathic region as a measured object includes: a variable wavelength light source (15); a light splitting portion (19) that splits light-source light emitted from the variable wavelength light source (15) into reference light (29) and measuring light (28); an interference portion (19) that causes the measuring light (28) and the reference light (29) to interfere with each other, thereby generating interference light; a photodetection portion (41) that measures the interference light; and an arithmetic portion (27b) that ...
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    5. Optical image measuring device, optical image measuring program, fundus observation device, and fundus observation program

      Optical image measuring device, optical image measuring program, fundus observation device, and fundus observation program
      An optical image measuring device which can form a highly reliable image even if an object moves during scanning of a signal light is provided. An optical image forming device 1 comprises: an interferometer that splits a low coherence light L0 into a signal light LS and a reference light LR and generates an interference light LC by overlaying the signal light LS reflected by a fundus oculi with the reference light LR reflected by a reference mirror 14; a CCD 34 which receives the interference light LC and outputs a detection signal; Galvanometer mirrors 22 and 23 to scan ...
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    6. Multiplexing spectrum interference optical coherence tomography

      Multiplexing spectrum interference optical coherence tomography
      The present invention achieves multiplexing spectrum interference optical coherence tomography capable of full-range OCT measurement that causes no delays in measurement time due to high-order scans and is also free from complex conjugated images. This multiplexing spectrum interference optical coherence tomography comprises: a first beam splitter 3 positioned in an optical path 2 from a light source 1 and used to separate an object light 4 and a reference light 5; a galvano mirror 6 positioned in the optical path of the object light 4 and used to scan the object light onto a measured object 8; a second beam ...
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    7. Polarization-Sensitive Optical Coherence Tomography of Necrotizing Scleritis

      A polarization-sensitive swept-source optical coherence tomography system (central wavelength: 1,310 nm; A-line rate: 20 kHz) was developed to evaluate the three-dimensional structure of the anterior eye segment with the phase retardation associated with the anterior segment birefringence of the eyes. Evaluation of normal eyes and an eye with necrotizing scleritis was performed. In the sclera of the normal eyes, a striking polarization change was observed in the cumulative phase retardation images and the boundary of the sclera could be readily detected. In the eye with necrotizing scleritis, phase retardation at the sclera was low in an extensive area; this ...
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    8. Investigation of multifocal choroiditis with panuveitis by three-dimensional high-penetration optical coherence tomography

      A single case of multifocal choroiditis with panuveitis (MFCPU) was investigated by a three-dimensional (3-D) high-penetration optical coherence tomography. The HP-OCT is based on a swept-source OCT technology, uses a probe beam with a center wavelength of 1060 nm, and possesses a depth resolution of 10.4 [mu] min tissue. Two eyes of an MFCPU patient were involved in this study. The eyes were also examined by color fundus photograph, fluorescein angiography (FA), and indocyanine green angiography (ICGA). Findings in these four modalities are comparatively discussed. The OCT scans revealed the following characteristic properties of the lesion sites. Thinning of ...
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    9. Visualization of Sub-retinal Pigment Epithelium Morphologies of Exudative Macular Diseases by High-Penetration Optical Coherence Tomography

      PURPOSE. To evaluate the clinical significance of the newly developed long-wavelength probe optical coherence tomography (LP-OCT) for the diagnosis of exudative macular diseases. METHODS. Fourteen eyes of 13 participants were prospectively enrolled in the study. There were seven type I and five type II choroidal neovascularization (CNV) cases associated with age-related macular degeneration and idiopathic neovascularization and one case of polypoidal choroidal vasculopathy (PCV). A custom-built LP-OCT based on swept-source OCT (SS-OCT) technology was used. This new OCT uses a probe beam with a wavelength of 1060 nm that provides deeper penetration into the choroid and higher image contrast to ...
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    10. Imaging Polarimetry in Age-Related Macular Degeneration

      purpose. To evaluate the birefringence properties of eyes with age-related macular degeneration (AMD). To compare the information from two techniques—scanning laser polarimetry (GDx) and polarization-sensitive spectral-domain optical coherence tomography (OCT)—and investigate how they complement each other. methods. The authors prospectively examined the eyes of two healthy subjects and 13 patients with exudative AMD. Using scanning laser polarimetry, they computed phase-retardation maps, average reflectance images, and depolarized light images. To obtain polarimetry information with improved axial resolution, they developed a fiber-based, polarization-sensitive, spectral-domain OCT system and measured the phase retardation associated with birefringence in the same eyes. results. Both ...
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    11. Polarization-sensitive swept-source optical coherence tomography with continuous polarization modulation

      Masahiro Yamanari, Shuichi Makita, Toyohiko Yatagai et al. We present fiber-based polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) with continuous polarization modulation. The light source is a high-speed wavelength sweeping source with 1.3 um center wavelength and 20 kHz sweeping frequency. A resonant electro-optic modulator mod ... [Proc. SPIE Int. Soc. Opt. Eng. 6847, 68471J (2008)] published Mon Feb 18, 2008.
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    12. Retinal blood flow measurement by using optical coherence tomography

      Shuichi Makita, Tapio Fabritius, Masahiro Miura et al. Quantification of the three-dimensional (3D) retinal vessel structure and blood flow is demonstrated. 3D blood flow distribution is obtained by Doppler optical coherence angiography (D-OCA). Vessel parameters, i.e. diameter, orientation, and position, are determined in an en face vessel image. The D ... [Proc. SPIE Int. Soc. Opt. Eng. 6847, 68470J (2008)] published Mon Feb 18, 2008.
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    13. Imaging the anterior eye segment by polarization-sensitive spectral-domain and swept-source optical coherence tomography

      Masahiro Miura, Masahiro Yamanari, Toyohiko Yatagai et al. Polarization-sensitive optical coherence tomography (PS-OCT) has been developed to measure the birefringent properties of the human eye. In the retina, retinal nerve fiber layer and retinal pigment epitherial layer have the characteristic birefringent properties. In addition to such normal tissue, a ... [Proc. SPIE Int. Soc. Opt. Eng. 6844, 68441C (2008)] published Mon Feb 11, 2008.
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    1-13 of 13
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  2. Topics in the News

    1. (10 articles) Yoshiaki Yasuno
    2. (9 articles) University of Tsukuba
    3. (5 articles) Masahiro Miura
    4. (5 articles) Masahiro Yamanari
    5. (4 articles) Shuichi Makita
    6. (1 articles) University of Oulu
    7. (1 articles) Tokyo Medical University
    8. (1 articles) Hisashi Tsukada
    9. (1 articles) Tapio E. J. Fabritius
    10. (1 articles) Topcon Medical Systems
    11. (1 articles) South China Normal University
    12. (1 articles) Indiana University
    13. (1 articles) Donald T. Miller
    14. (1 articles) Boston Scientific
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    Multiplexing spectrum interference optical coherence tomography Optical image measuring device, optical image measuring program, fundus observation device, and fundus observation program Dental optical coherence tomograph Optical coherence tomography angiography (OCTA) findings in Serpiginous Choroiditis Changes in retinal layer thickness with maturation in the dog: an in vivo spectral domain - optical coherence tomography imaging study Optical coherence tomography angiography analysis of fabry disease An unsupervised hierarchical approach for automatic intra‐retinal cyst segmentation in spectral‐domain optical coherence tomography images Towards quantitative assessment of burn based on photoacoustic and optical coherence tomography Cellular Scale Imaging of Transparent Retinal Structures and Processes Using Adaptive Optics Optical Coherence Tomography Optical Coherence Tomography Imaging in Acute Myocardial Infarction: Calcified Nodule as a Culprit Lesion Study of low-peak-power highly coherent broadband supercontinuum generation through a dispersion-engineered Si-rich silicon nitride waveguide Invasive Coronary Artery Imaging Using Optical Coherence Tomography: A Cost-effectiveness and Implementation Process Analysis (Thesis)