• Proceedings of the Optical Society of Korea Conference
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• 2003.02a
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• pp.290-291
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• 2003

Optical Coherence Tomography is a new medical dianostic imaging technology which can perform micron resolution cross-sectional or tomograpic imaging in biological tissue. In this paper, we analyze OCT system. And we have 2-dimensional OCT image implementation using low coherence SLD.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.43 no.3
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• pp.247-254
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• 2017

Optical Coherence Tomography (OCT) is a non-invasive imaging method that utilizes the optical scattering and interference for visualizing the surface as well as cross-sectional structures of tissue. OCT has been used for diagnosing diseases in early stage in various medical fields, but an application in cosmetics is still at early stage. In this study, OCT was adopted to evaluate skin texture and wrinkle. Results showed similar patterns of evaluation with PRIMOS in the assessment using replica. In addition, OCT produced smaller errors at different angles compared to the PRIMOS in the assessment using 3-dimensional models of wrinkles. The resolution of the image was also high enough to differentiate the images of before and after the application of makeup products. Possible use of OCT in the evaluation of fine wrinkle assessment was studied in this research. Further development of methods is necessary to provide more evidences of the effectiveness.

• Korean Journal of Optics and Photonics
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• v.18 no.4
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• pp.274-279
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• 2007

We fabricated and characterized an optical delay line for optical coherence tomography (OCT). The delay line was composed of a cylindrical piezoelectric transduce (PZT) and a single mode optical fiber. The OCT system used a duplex scanning optical delay line which was symmetrically driven in the reference and sample arms. We showed that the sinusoidal-wave was superior to a triangular-wave for driving the optical delay line for scanning depth and repeatability.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.3
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• pp.239-248
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• 2004

Optical coherence tomography(OCT) is high resolution imaging system which can see the cross section of microscopic organs in the living tissue. In this paper, we analyze the relation between the light source and the resolution of modulated signal in Michelson interferometer. We construct 1-D OCT signal processing hardware such as amplifiers, filters, and demodulate electronic signals from the photo detector. In order to get 2-D OCT image, the synchronization among optical delay line, sample stage and A/D converter is dealt with. In experiments, we verify analog and digital signal processing blocks which apply to the stacks of glasses. Finally we aquire high resolution 2-D OCT image with respect to the onion tissue. We expect that this result can be applied to the medical instrument through performance improvement.

• Journal of Veterinary Clinics
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• v.30 no.4
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• pp.324-328
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• 2013

A 5-year-old intact male Yorkshire terrier dog was referred with a 1-week history of blindness. In both eyes, menace responses and pupillary light reflexes were absent. The indirect ophthalmoloscopy revealed multiple small gray-white and discoloration lesion in mid-nontapetum area in both eyes. Electroretinograms showed diminished amplitude of a- and b-waves. Multifocal serous retinal detachments were detected with optical coherence tomography (OCT) over the small gray-white and discoloration lesion in the fundus. After one week of treatments, the indirect ophthalmoloscopy showed that irregular patches and hyperpigmentation in the center of hyperreflectivity area. Reattachment and retinal thinning were observed by the OCT. The results indicate that OCT scanning is considered to be a useful method for retinal evaluation in dogs with chorioretinitis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.639-642
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• 2012

Optical coherence tomography(OCT) can provide real-time and non-invasive subsurface imaging with ultra-high resolution of micrometer scale. However, conventional OCT systems generally have a limited imaging depth range within a depth of only 1-2 mm. To overcome the limitation, we have proposed an active surface tracking algorithm used in common-path Fourier-domain OCT system in order to extend the imaging depth range. The surface tracking algorithm based on the threshold and Savitzky-Golay filter of A-scan data was applied to real-time tracking. The algorithm has controlled a moving stage according to the sample's surface variance in real time. An OCT image obtained by the algorithm clearly show an extended imaging depth range. Consequently, the proposed algorithm demonstrated the potential for improving the conventional OCT systems with limitary depth range.

• Korean Journal of Optics and Photonics
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• v.26 no.1
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• pp.1-8
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• 2015

The most common cause of a heart attack is known as coronary artery disease, which narrows the arteries and reduces the blood flow to the heart. To treat coronary artery stenosis, percutaneous coronary intervention (PCI) (a nonsurgical procedure to install a stent, which holds the artery wall open) is performed. Intracoronary optical coherence tomography (OCT) is a catheter-based, invasive optical imaging system. To determine whether PCI is appropriate, and to perform stent evaluation in a catheterization laboratory, OCT examinations are carried out. This review details the fundamental principles and technological status of intracoronary OCT imaging, and discusses the ongoing clinical applications to determine the benefits of OCT-guided PCI.

• Korean Journal of Veterinary Research
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• v.53 no.2
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• pp.137-141
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• 2013

To report retinal image of in a 6-year-old male castrated poodle dog with a 2-month history of nyctalopia using optical coherence tomography (OCT). Ocular reflexes were present in both eyes and slit lamp examination showed anterior subscapular cataract in the right eye. There were fundus abnormalities in both eyes similar to retinal degeneration. Scotopic electroretinograms (ERGs) revealed significantly subabnormal amplitudes and prolonged implicit time, whereas photopic ERGs were better maintained, although far from normal. OCT of affected dogs revealed generalized retinal thinning much more than a normal age-matched dog. Therefore, OCT scanning is considered to be a useful method for retinal evaluation in dogs with retinal degeneration.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.804-806
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• 2004

As a noninvasive imaging meathod, optical coherence tomography system has been extensively studied because it has some advantage such as imaging of high resolution, low cost, and compace size configuration. The optical power of the sample signal reflected from an object is usually very small in optical coherence tomography(OCT) due to absorption and scattering in a sample material. Furthermore, there happens a serious loss of sample signal power in a fiber coupler because it does not transfer to a photodetector but return to the optical source. In order to improve the SNR of OCT system, basic Michelson and Mach-Zehnder interferometer types were configured then, we compared simulation with measurement of reference sample Therefore, an On in configuration of Math-Zehnder interferometer was demonstrated in order to improve the signal to noise ratio

• Current Optics and Photonics
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• v.4 no.4
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• pp.330-335
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• 2020

We have investigated optimization of the working distance (WD) for a highly miniaturized imaging probe for endoscopic optical coherence tomography (OCT). The WD is the axial distance from the distal end of the imaging probe to its beam focus, which is demanded for dimensional margins of protective structures, operational safety, or full utilization of the axial imaging range of OCT. With an objective lens smaller than a few hundred micrometers in diameter, a micro-optic imaging probe naturally exhibits a very short WD due to the down-scaled optical structure. For a maximized WD careful design is required with the optical aperture of the objective lens optimally filled by the incident beam. The diffraction-involved effect was taken into account in our analysis of the apertured beam. In this study, we developed a simple design formula on the maximum achievable WD based on our diffraction simulation. It was found that the maximum WD is proportional to the aperture size squared. In experiment, we designed and fabricated very compact OCT probes with long WDs. Our 165-㎛-thick fiber-optic probes provided WDs of 3 mm or longer w ith reasonable OCT imaging performance.