Dr. Kohji Ohbayashi Profile

Dr. Kohji Ohbayashi

Chief at Systems Engineering Inc.

SPIE Involvement:

Author

Publications (28)

Proceedings Article | 27 February 2020 Paper

Morphological diversity of lacrimal canaliculus observed by dynamic OCT with extrinsic contrast agent

Reiko Yoshimura, Dong-Hak Choi, Masahiro Fujimoto, Akihito Uji, Fumiko Hiwatashi, Kohji Ohbayashi

Proceedings Volume 11218, 112181T (2020) https://doi.org/10.1117/12.2545365

KEYWORDS: Optical coherence tomography, Image segmentation, 3D image reconstruction, 3D image processing

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Proceedings Article | 28 February 2019 Paper

Lacrimal canaliculus imaging by dynamic OCT using extrinsic contrast agent

Reiko Yoshimura, Dong-hak Choi, Masahiro Fujimoto, Akihito Uji, Fumiko Hiwatashi, Kohji Ohbayashi

Proceedings Volume 10858, 108581H (2019) https://doi.org/10.1117/12.2508137

KEYWORDS: Optical coherence tomography, Image segmentation, Eye, 3D image processing

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Proceedings Article | 17 February 2017 Paper

Speckle variance optical coherence tomography using an SS-OCT system and an extended k-sampling clock

Reiko Yoshimura, Dong-Hak Choi, Kohji Ohbayashi

Proceedings Volume 10053, 100532P (2017) https://doi.org/10.1117/12.2250717

KEYWORDS: Optical coherence tomography, Coherence (optics), Light sources, Biomedical optics, Point spread functions, Tissues, Imaging systems, Speckle, Reflectors, Refractive index, Signal generators, Laser resonators

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Proceedings Article | 20 March 2013 Paper

Enhancement of the depth range up to 13.8 mm with filtered external k-sampling-clock in an SS-OCT system using a reflective Fabry-Perot tunable laser

Hisashi Yamada, Yasuo Niimura, Fumiko Hiwatashi, Dong-Hac Choi, Kohji Ohbayashi

Proceedings Volume 8571, 85710C (2013) https://doi.org/10.1117/12.2002226

KEYWORDS: Optical coherence tomography, Optical filters, Clocks, Point spread functions, Tunable lasers, Signal detection, Fabry–Perot interferometers, Image segmentation, Reflectivity, Linear filtering

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Proceedings Article | 14 February 2012 Paper

Image diversity, shape modification with accommodation, dynamical change with accommodation, and age dependence of the ciliary body imaged by optical coherence tomography

Kimiya Shimizu, Nobuyuki Satou, Akihito Igarashi, Motoi Nakanishi, Atsushi Goto, Donghak Choi, Reiko Yoshimura, Hideaki Hiro-Oka, Hiroyuki Furukawa, Kohji Ohbayashi

Proceedings Volume 8209, 820909 (2012) https://doi.org/10.1117/12.905401

KEYWORDS: Optical coherence tomography, Eye, Image segmentation, Iris, 3D image processing, Video, Sclera, Ultrafast phenomena, Imaging systems, Refraction

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Proceedings Article | 30 January 2012 Paper

Discretely swept optical coherence tomography system using super-structure grating distributed Bragg reflector lasers at 1561-1639nm

D. Choi, R. Yoshimura, H. Hiro-Oka, H. Furukawa, A. Goto, N. Satoh, A. Igarashi, M. Nakanishi, K. Shimizu, K. Ohbayashi

Proceedings Volume 8213, 82132F (2012) https://doi.org/10.1117/12.905413

KEYWORDS: Optical coherence tomography, Point spread functions, Interference (communication), Tissue optics, Distributed Bragg reflectors, Frequency combs, Laser systems engineering, Image segmentation, Biomedical optics, Laser optics

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Proceedings Article | 30 January 2012 Paper

Optical amplification of the signal and sensitivity of the ultrafast spectral domain optical coherence tomography at an A-scan rate of 10MHz in a wavelength region of 1300nm

D. Choi, H. Hiro-oka, K. Shimizu, K. Ohbayashi

Proceedings Volume 8213, 82131F (2012) https://doi.org/10.1117/12.906536

KEYWORDS: Optical coherence tomography, Point spread functions, Field programmable gate arrays, Data processing, Skin, 3D image processing, Data acquisition, Biomedical optics, Ultrafast phenomena, Semiconductor optical amplifiers

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Proceedings Article | 30 January 2012 Paper

Detailed software design of an ultra-parallel ultra-high speed SD-OCT for real-time 4D display at 12 volume/second

H. Hiro-Oka, D. Choi, K. Shimizu, K. Ohbayashi

Proceedings Volume 8213, 821339 (2012) https://doi.org/10.1117/12.906948

KEYWORDS: Optical coherence tomography, Field programmable gate arrays, Data acquisition, Data processing, 3D image processing, 3D displays, Demultiplexers, Interfaces, Graphics processing units, 3D acquisition

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Proceedings Article | 18 February 2011 Paper

Cross-sectional imaging of extracted jaw bone of a pig by optical coherence tomography

Noriko Tachikawa, Reiko Yoshimura, Kohji Ohbayashi

Proceedings Volume 7884, 78840F (2011) https://doi.org/10.1117/12.873943

KEYWORDS: Optical coherence tomography, Bone, Surgery, Nerve, Tissues, Laser dentistry, In vivo imaging, Distance measurement, Refractive index, Natural surfaces

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Proceedings Article | 12 February 2011 Paper

Ultra-high speed real-time 4D display system installed in ultra-high-speed parallel OCT system at a volume rate of 12 volumes/sec

K. Ohbayashi, D. Choi, H. Hiro-oka, A. Kubota, T. Ohno, R. Ikeda, K. Shimizu

Proceedings Volume 7889, 78891Z (2011) https://doi.org/10.1117/12.874576

KEYWORDS: Optical coherence tomography, Data acquisition, 3D displays, 3D image processing, Video, Tissues, Biopsy, Data processing, Diagnostics, Field programmable gate arrays

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Proceedings Article | 12 February 2011 Paper

Full-range imaging of the whole anterior segment of eye by high-speed optical frequency domain imaging using a reflective Fabry-Perot tunable laser

Hiroyuki Furukawa, Hideaki Hiro-Oka, Reiko Yoshimura, Dong-Hak Choi, Motoi Nakanishi, Akihito Igarashi, Kohji Ohbayashi, Kimiya Shimizu

Proceedings Volume 7885, 78850V (2011) https://doi.org/10.1117/12.874077

KEYWORDS: Image segmentation, Eye, Optical imaging, Cornea, Crystals, Imaging systems, Reflectivity, Fabry–Perot interferometers, Tunable lasers, Iris

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Proceedings Article | 18 February 2009 Paper

24 mm depth range discretely swept optical frequency domain imaging in dentistry

Hideo Kakuma, DongHak Choi, Hiroyuki Furukawa, Hideaki Hiro-Oka, Kohji Ohbayashi

Proceedings Volume 7162, 716208 (2009) https://doi.org/10.1117/12.807235

KEYWORDS: Optical coherence tomography, Point spread functions, Laser dentistry, Reflectors, Imaging systems, Optical imaging, Teeth, Light sources, Dentistry, Reflectometry

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Proceedings Article | 5 March 2008 Paper

Doppler optical coherence tomography measurements in discretely swept optical frequency domain imaging

Reiko Yoshimura, Hideaki Hiro-Oka, DongHak Choi, Hiroyuki Furukawa, Naoki Fujiwara, Kohji Ohbayashi

Proceedings Volume 6847, 68472G (2008) https://doi.org/10.1117/12.764331

KEYWORDS: Optical coherence tomography, Doppler tomography, Light sources, Imaging systems, Optical imaging, Doppler effect, Optical testing, Biomedical optics, Photonics, Phase shifts

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Proceedings Article | 5 March 2008 Paper

Single-mode 140 nm swept light source realized by using SSG-DBR lasers

N. Fujiwara, R. Yoshimura, K. Kato, H. Ishii, F. Kano, Y. Kawaguchi, Y. Kondo, K. Ohbayashi, H. Oohashi

Proceedings Volume 6847, 684713 (2008) https://doi.org/10.1117/12.765392

KEYWORDS: Wavelength tuning, Optical coherence tomography, Terahertz radiation, Light sources, S band, Tunable filters, Image enhancement, Semiconductor lasers, Absorption, Oscilloscopes

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Proceedings Article | 18 February 2008 Paper

Penetration depth of optical frequency domain imaging at wavelengths of 1310 nm and 1550 nm

Hiroyuki Furukawa, DongHak Choi, Hideaki Hiro-Oka, Reiko Yoshimura, Motoi Nakanishi, Kimiya Shimizu, Kohji Ohbayashi

Proceedings Volume 6847, 68472V (2008) https://doi.org/10.1117/12.766846

KEYWORDS: Tissue optics, Biomedical optics, Hard tissue optics, Optical imaging, Optical coherence tomography, Coherence (optics), Laser scanners, 3D scanning, Receivers, Mirrors

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Proceedings Article | 18 February 2008 Paper

60 MHz A-line rate ultra-high speed Fourier-domain optical coherence tomography

K. Ohbayashi, D. Choi, H. Hiro-Oka, H. Furukawa, R. Yoshimura, M. Nakanishi, K. Shimizu

Proceedings Volume 6847, 68470M (2008) https://doi.org/10.1117/12.764133

KEYWORDS: Optical coherence tomography, Data acquisition, Demultiplexers, Scanners, 3D image processing, Mirrors, Point spread functions, Terahertz radiation, Imaging systems, Electronics

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Proceedings Article | 18 February 2008 Paper

Use of cosine tapered window to improve dynamic range of OCT without loss of resolution

Hideaki Hiro-Oka, DongHak Choi, Hiroyuki Furukawa, Reiko Yoshimura, Kohji Ohbayashi, Takeyuki Wakabayashi

Proceedings Volume 6847, 68472C (2008) https://doi.org/10.1117/12.761459

KEYWORDS: Optical coherence tomography, Tunable lasers, Light sources, Mirrors, Fourier transforms, L band, Skin, Optical imaging, Laser development, Signal detection

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SPIE Journal Paper | 1 January 2008 Open Access

Optical imaging of hard and soft dental tissues using discretely swept optical frequency domain reflectometry optical coherence tomography at wavelengths from 1560 to 1600 nm

Hideo Kakuma, Kohji Ohbayashi, Yasuhiko Arakawa

JBO, Vol. 13, Issue 01, 014012, (January 2008) https://doi.org/10.1117/12.10.1117/1.2839042

KEYWORDS: Optical coherence tomography, Tissues, Teeth, Laser development, L band, Optical imaging, Reflectometry, In vitro testing, In vivo imaging, Tissue optics

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Proceedings Article | 8 March 2007 Paper

Optical imaging of hard and soft dental tissues using discretely swept OFDR-OCT

Hideo Kakuma, Kohji Ohbayashi, Yasuhiko Arakawa

Proceedings Volume 6425, 642505 (2007) https://doi.org/10.1117/12.699897

KEYWORDS: Tissues, Mirrors, Collimators, Laser development, Optical imaging, Lasers in dentistry, Microscopes, Reflectometry, Mach-Zehnder interferometers, Reflectors

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