• 제목/요약/키워드: Optical Tomography

검색결과 303건 처리시간 0.021초

SS-OCT 방식을 이용한 생체의 표피단면 영상 획득 (Acquirement of in vivo epidermal cross-sectional image by using swept source optical coherence tomography)

  • 김훈섭;임해진;엄진섭
    • 산업기술연구
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    • 제28권A호
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    • pp.163-166
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    • 2008
  • In this paper, the swept source optical coherence tomography system has realized using a free-space interferometer based on a beam splitter. Personal computer has completed the control for tunable wavelength laser digitally and the B-scan motor as well. From each experiment for an onion and a salmon egg, we confirmed that the in vivo epidermal cross-sectional images for them can be obtained appropriately.

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Optical Coherence Tomography를 이용한 원발성 맥락망막염 이환견의 진단 및 치료 (The Diagnosis and Treatment of Primary Chorioretinitis using Optical Coherence Tomography in a Dog)

  • 지동범;유석종;서강문;정만복
    • 한국임상수의학회지
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    • 제30권4호
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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.

Complex Conjugate Resolved Retinal Imaging by One-micrometer Spectral Domain Optical Coherence Tomography Using an Electro-optical Phase Modulator

  • Fabritius, Tapio E.J.;Makita, Shuichi;Yamanari, Masahiro;Myllyla, Risto A.;Yasuno, Yoshiaki
    • Journal of the Optical Society of Korea
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    • 제15권2호
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    • pp.111-117
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    • 2011
  • Full-range spectral domain optical coherence tomography (SD-OCT) with a 1-${\mu}m$ band light source is shown here. The phase of the reference beam is continuously stepped while the probing beam scans the sample laterally (B-scan). The two dimensional spectral interferogram obtained is processed by a Fourier transform method to obtain a complex spectrum leading to a full-range OCT image. A detailed mathematical explanation of the complex conjugate resolving method utilized is provided. The system's measurement speed was 7.96 kHz, the measured axial resolution was $9.6{\mu}m$ in air and the maximum sensitivity 99.4 dB. To demonstrate the effect of mirror image elimination, In vivo human eye pathology was measured.

Common-path Optical Coherence Tomography for Biomedical Imaging and Sensing

  • Kang, Jin-U.;Han, Jae-Ho;Liu, Xuan;Zhang, Kang
    • Journal of the Optical Society of Korea
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    • 제14권1호
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    • pp.1-13
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    • 2010
  • This paper describes a development of a fiber optic common-path optical coherence tomography (OCT) based imaging and guided system that possess ability to reliably identify optically transparent targets that are on the micron scale; ability to maintain a precise and safe position from the target; ability to provide spectroscopic imaging; ability to imaging biological target in 3-D. The system is based on a high resolution fiber optic Common-Path OCT (CP-OCT) that can be integrated into various mini-probes and tools. The system is capable of obtaining >70K A-scan per second with a resolution better than $3\;{\mu}m$. We have demonstrated that the system is capable of one-dimensional real-time depth tracking, tool motion limiting and motion compensation, oxygen-saturation level imaging, and high resolution 3-D images for various biomedical applications.

광간섭 단층촬영(OCT)용 PZT 광경로 지연기에서의 편광모드 분산 및 열요동 보상 (Compensations of Polarization Mode Dispersion and Thermal Drift in Optical Coherence Tomography with PZT Optical Delay Lines)

  • 김영관;박성진;김용평
    • 한국광학회지
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    • 제16권6호
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    • pp.547-552
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    • 2005
  • 광간섭 단층촬영(OCT)용으로 원통형 압전소자(PZT)와 단일모드 광섬유를 이용한 광경로 지연기를 제작하여 그 특성을 분석하였다. 광경로 지연기에서 발생하는 편광모드 분산은 편광조절기로 조절하였고, 열요동을 2중 광경로 지연기를 구성하여 최소화하였다. 이중 광경로 지연기는 단일 광경로 지연기에 비해 2배의 측정 깊이와 속도를 구현하여 $18.6\pm0.5{\mu}m$의 해상도. 측정 깊이 1.68 mm, 측정 녹도 360.4 mm/s를 각각 얻었다.

광학 영상기를 위한 실시간 영상 신호 처리에 관한 연구 (Video Rate Image Signal Processing for Optical Coherence Tomography)

  • 나지훈;이병하;이창수
    • 제어로봇시스템학회논문지
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    • 제10권3호
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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.

나노초 레이져를 이용한 광-초음파 이미지 결상법 (In vivo functional photoacoustic imaging)

  • Oh, Jung-Taek;Li, Meng-Lin;Song, Kwang-Hyun;Xie, Xueyi;Stoica, George;Wang, Lihong V.
    • 한국광학회:학술대회논문집
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    • 한국광학회 2006년도 동계학술발표회 논문집
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    • pp.359-360
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    • 2006
  • Functional photoacoustic tomography is a new non-invasive imaging modality, and it is emerging as a very practical method for imaging biological tissue structures by means of laser-induced ultrasound. Structures with high optical absorption, such as blood vessels, can be imaged with the spatial resolution of ultrasound, which is not limited by the strong light scattering in biological tissues. By varying wavelengths of the laser light and acquiring photoacoustic images, optical absorption spectrum of each image pixel is found. Since the biochemical constituents of tissues determine the spectrum, useful functional information like oxygen saturation ($SO_2$) and total haemoglobin concentration (HbT) can be extracted. In this study, as a proof-of-principle experiment, hypoxic brain tumor vasculature and traumatic brain injury (TBI) of small animal brain are imaged with functional photoacoustic tomography. High resolution brain vasculature images of oxygen saturation and total hemoglobin concentration are provided to visualize hypoxic tumor vasculature, and hemorrhage on the cortex surface by the TBI.

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Ocular coherence tomography를 이용한 개의 망막변성증 평가 (Assessment of retinal degeneration with optical coherence tomography in a dog)

  • 지동범;유석종;서강문;정만복
    • 대한수의학회지
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    • 제53권2호
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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.

위상천이원리 와 PS-OCT시스템을 적용한 역산란광의 매질 깊이별 스톡스변수 추출 (Depth-resolved Stokes parameters of light backscattered from turbid media with polarization-sensitive optical coherence tomography system and successive phase-shifting algorithm)

  • Oh, Jung-Taek;Kim, Seung-Woo
    • 한국광학회:학술대회논문집
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    • 한국광학회 2003년도 제14회 정기총회 및 03년 동계학술발표회
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    • pp.286-287
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    • 2003
  • Polarization-sensitive optical coherence tomography (PS-OCT) was developed to image highly scattering tissues with accounting for polarization effects in the sample. These polarization-sensitive images can provide additional information on the structure of the tissue because of a polarization state of the light is changed at its interaction with biological tissues. The scattering and birefringence are two phenomena, which change the polarization state of light passing through medium. (omitted)

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