• Journal of the Optical Society of Korea
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• 제16권2호
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• pp.133-140
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• 2012

In this study we investigate the use of 2D and 3D scanning optical coherence tomography (OCT) technology for use in apple blotch diagnosis. In order to test the possible application of OCT as a detection tool for apple trees affected by Marssonina coronaria, we conducted several experiments and compared the results from both healthy and infected leaves. Using OCT, we found several distinctive features in the subsurface boundary regions of both the diseased and healthy leaves. Our results indicate that leaves from diseased trees, while still appearing healthy, can be affected by M. coronaria. The A-scan analysis method confirmed that the boundaries found under the subsurface layers can be faint. This shows that M. coronaria can exert its influence on entire apple trees (as opposed to only on leaves with lesions) once it infects healthy trees. Our results indicate that OCT can be used as a noninvasive tool for the diagnosis of fungal disease in apple trees. Microscopic imaging results, performed as a histological study for comparison, correlated well with the OCT results.

• 센서학회지
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• 제22권4호
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• pp.262-267
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• 2013

We developed a real-time screening system using optical coherence tomography (OCT) to distinguish the fruitful melon seeds efficiently. Cross-section images of melon seeds infected with Cucumber green mottle mosaic virus (CGMMV) showed an additional layer that did not appear in normal seeds. Additional layer appeared under $100{\sim}300{\mu}m$ from the surface of the seed. OCT can visualize the micro-structural and morphological changes of the internal seed structure. Real-time OCT seed screening system provided the real-time, non-destructive, cross-section image and quantitative information such as A-scan analysis of selected region in the cross-section image. We can distinguish the viral infection seeds while monitoring the averaged A-scan analysis graph in real-time by considering the second peak value of the graph which refers to the layer that occurred owing to the virus. Real-time OCT seed screening system could assist to distinguish the disease caused by CGMMV.

• Journal of the Optical Society of Korea
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• 제17권1호
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• pp.68-72
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• 2013

We developed an SD-OCT (Spectral Domain-Optical Coherence Tomography) system which uses a GPU (Graphics Processing Unit) for processing. The image size from the SD-OCT system is $1024{\times}512$ and the speed is 110 frame/sec in real-time. K-domain linearization, FFT (Fast Fourier Transform), and log scaling were included in the GPU processing. The signal processing speed was about 62 ms using a CPU (Central Processing Unit) and 1.6 ms using a GPU, which is 39 times faster. We performed an in-vivo retinal scan, and reconstructed a 3D visualization based on C-scan images. As a result, there were minimal motion artifacts and we confirmed that tomograms of blood vessels, the optic nerve, and the optic disk are clearly identified. According to the results of this study, this SD-OCT can be applied to real-time 3D display technology, particularly auxiliary instruments for eye operations in ophthalmology.

• Current Optics and Photonics
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• 제5권5호
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• pp.532-537
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• 2021

We present a compact endoscopic probe in a needle form which has a fast beam-scanning capability for optical coherence tomography (OCT). In our study, a beam-scanning OCT imaging needle was fabricated with a 26G syringe needle (0.46 mm in outer diameter) and a thin OCT imaging probe based on the stepwise transitional core (STC) fiber. The imaging probe could freely rotate inside the needle for beam scans. Hence, OCT imaging could be performed without rotation or translation of the needle body. In our design, the structural integrity of the needle's steel tubing was preserved for mechanical robustness. Probing the optical signal was performed through the needle's own window formed at the end. For hand-held operation of our imaging needle, a light and compact scanner module (130 g and 45 × 53 × 60 mm³) was devised. Connected to the imaging needle, it could provide rotational actuation driven by a galvanometer. Because of its finite actuation range, our scanner module did not need a fiber rotary joint which might add undesirable complexity. The beam scan speed was 20 Hz and supported 20 frames per second at the maximum for endoscopic OCT imaging.

• 한국광학회:학술대회논문집
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• 한국광학회 2002년도 하계학술발표회
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• pp.86-87
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• 2002

생체의용 Optical Coherence Tomography (OCT)는 살아있는 표피의 내부 미세구조의 고해상도 단면 영상을 얻는 기술이다. OCT는 1-2mm의 깊이의 작은 혈관이나 표피의 내부 구조 영상을 얻을 수 있다. OCT의 광원으로는 800nm대와 1300nm대의 파장을 갖는 Edge-emitting Light-Emitting Diode(ELED)와 Super-Luminescent diode(SLD)를 많이 사용하고 있다. 그러나 기존 광원의 가간섭성 길이가 정밀의료계측 분야의 응용에서 요구하는 해상도에 충분하지 못하다. (중략)

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2707-2709
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• 2002

In this paper, we suggest new optical eye-diagnosis medical equipment. First, we simulate light propagation in bio-tissue using MC method. Second, we propose the OCT design parameter using Michelson interferometer.

• 대한한의학회지
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• 제44권2호
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• pp.170-180
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• 2023

Objectives: This is a case report on the treatment of one patient with acute angle-closure glaucoma using traditional Korean medicine. Methode: We assessed the progression of acute angle-closure glaucoma by analyzing Optical Coherence Tomography(OCT) results. Results: Acute angle closure glaucoma did not progress to OCT after treatment. Conculsion: We obtained results from OCT examinations indicating that the progression of acute angle-closure glaucoma had ceased after Korean herbal medicine treatment.

• 센서학회지
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• 제22권1호
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• pp.84-88
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• 2013

In this paper, the low price signal generator with capability of frequency high-resolution and variable sync pulse has implemented. It fulfils well the requirements for SS-OCT of the frequency resolution less than 1Hz, frequency stability of ${\leq}{\pm}0.5Hz$/10 min and variable sync pulse output timing. Through its performance test applied to wavelength swept laser, 120 nm sweeping range and 10 mW average optical power were obtained. This shows that the realized sine-wave generator can replace the commercial high cost and high performance signal generators employed by current SS-OCT systems.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2640-2644
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• 2013

The all-hydrocarbon i,i+4 stapling system using an oct-4-enyl crosslink is one of the most widely employed chemical tools to stabilize an ${\alpha}$-helical conformation of a short peptide. This crosslinking system has greatly extended our ability to modulate intracellular protein-macromolecule interactions. The helix-inducing property of the i,i+4 staple has shown to be highly dependent on the length and the stereochemistry of the oct-4-enyl crosslink. Here we show that changing the double bond position within the i,i+4 staple has a considerable impact not only on the formation of the crosslink but also on ${\alpha}$-helix induction. The data further increases the understanding of the structure-activity relationships of this valuable chemical tool.

• 산업기술연구
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• 제28권B호
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• pp.239-244
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• 2008

We have realized the swept source optical coherence tomography(SS-OCT) by using the self-fabricated wavelength swept laser(wavelength tuning range : 80nm, line-width : 0.12nm, wavelength sweeping rate : 50Hz). In addition, we have used the dual balanced detector that could make a mirror image in OCT display suppressed. We can also fabricate the comb filter of Michelson interferometer type for fast-signal processing in OCT. Using this SS-OCT system for measuring an mirror, a 1mm-depth glass and an onion, we confirmed that the in vivo epidermal cross-sectional images for them can be obtained appropriately.