• 제목/요약/키워드: Optical coherence

검색결과 342건 처리시간 0.021초

Optical Monitoring of Tumors in BALB/c Nude Mice Using Optical Coherence Tomography

  • Song, Hyun-Woo;Lee, Sang-Won;Jung, Myung-Hwan;Kim, Kye Ryung;Yang, Seungkyoung;Park, Jeong Won;Jeong, Min-Sook;Jung, Moon Youn;Kim, Seunghwan
    • Journal of the Optical Society of Korea
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    • 제17권1호
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    • pp.91-96
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    • 2013
  • We report a method for optical monitoring of tumors in an animal model using optical coherence tomography (OCT). In a spectral domain OCT system, a superluminescent diode light source with a full width of 66 nm at half maximum and peak wavelength of 950 nm was used to take images having an axial resolution of 6.8 ${\mu}m$. Cancer cells of PC-3 were cultured and inoculated into the hypodermis of auricle tissues in BALB/c nude mice. We observed tumor formation and growth at the injection region of cancer cells in vivo and obtained the images of tumor mass center and sparse circumferences. On the $5^{th}$ day from an inoculation of cancer cells, histological images of the tumor region using cross-sectional slicing and dye staining of specimens were taken in order to confirm the correlation with the high resolution OCT images. The OCT image of tumor mass compared with normal tissues was analyzed using its A-scan data so as to obtain a tissue attenuation rate which increases according to tumor growth.

Statistical Characteristics of Polarization - Sensitive Optical Coherence Tomography for Tissue Imaging

  • Oh, Jung-Taek;Kim, Beop-Min;Kim, Seung-Woo
    • Journal of the Optical Society of Korea
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    • 제7권4호
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    • pp.211-215
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    • 2003
  • Statistical characteristics of the backscattered light from turbid tissues obtained by polarizationsensitive optical coherence tomography are investigated. The amplitude of the backscattered light is found to faithfully follow the Rayleigh distribution predicted by the scattering theory of electromagnetic waves in random media. The probability density function of the phase difference between the two orthogonal polarization components of the backscattered light is explicitly derived and then verified in comparison with the experimental data measured from in-vitro tissues of porcine ligament.

Murine Heart Wall Imaging with Optical Coherence Tomography

  • Kim Jee-Hyun;Lee Byeong-Ha
    • Journal of the Optical Society of Korea
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    • 제10권1호
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    • pp.42-47
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    • 2006
  • M-mode imaging of the in vivo murine myocardium using optical coherence tomography (OCT) is described. Application of conventional techniques (e.g. MRI, Ultrasound imaging) for imaging the murine myocardium is problematic because the wall thickness is less than 1.5 mm (20 g mouse), and the heart rate can be as high as six hundred beats per minute. To acquire a real-time image of the murine myocardium, OCT can provide sufficient spatial resolution ($10{\mu}m$) and imaging speed (1000 A-scans/s). Strong light scattering by blood in the heart causes significant light attenuation, which makes delineation of the endocardium-chamber boundary problematic. To measure the thickness change of the myocardium during one heart beat cycle, a myocardium edge detection algorithm is developed and demonstrated.

Wavelength-Swept Cascaded Raman Fiber Laser around 1300 nm for OCT Imaging

  • Lee, Hyung-Seok;Lee, Hwi Don;Jeong, Myung-Yung;Kim, Chang-Seok
    • Journal of the Optical Society of Korea
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    • 제19권2호
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    • pp.154-158
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    • 2015
  • We experimentally demonstrated a novel wavelength-swept laser using a cascaded Raman gain around 1310 nm. A 1064/1310 wavelength division multiplexing (WDM) coupler and coupled fiber Bragg gratings mirrors at 1064, 1117, 1175, 1240 nm are effectively used to increase the power efficiency in a laser ring cavity with highly non-linear fiber (HNLF) of 2 km. Linear wavelength sweeping is demonstrated with the 100 Hz triangular driving signal to fiber Fabry-Perot tunable filter (FFP-TF) around the 1310 nm region. The measured sweeping range and output power were 27 nm and 2.1 mW, respectively, which are suitable for optical coherence tomography (OCT) imaging.

Implementation of Cost-effective Common Path Spectral Domain Free-hand Scanning OCT System

  • Shoujing Guo;Xuan Liu;Jin U. Kang
    • Current Optics and Photonics
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    • 제7권2호
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    • pp.176-182
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    • 2023
  • Optical coherence tomography (OCT) is being developed to guide various ophthalmic surgical procedures. However, the high cost of the intraoperative OCT system limits its availability mostly to the largest hospitals and healthcare systems. In this paper, we present a design and evaluation of a low-cost intraoperative common-path free-hand scanning OCT system. The lensed fiber imaging probe is designed and fabricated for intraocular use and the free-hand scanning algorithm that could operate at a low scanning speed was developed. Since the system operates at low frequencies, the cost of the overall system is significantly lower than other commercial intraoperative OCT systems. The assembled system is characterized and shows that it meets the design specifications. The handheld OCT imaging probe is tested on multilayer tape phantom and ex-vivo porcine eyes. The results show that the system could be used as an intraoperative intraocular OCT imaging device.

Common-path Optical Interferometry for Stabilized Dynamic Contrast Imaging: A Feasibility Study

  • Seung-Jin, Lee;Young-Wan, Choi;Woo June, Choi
    • Current Optics and Photonics
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    • 제7권1호
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    • pp.65-72
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    • 2023
  • The motion of organelles inside a cell is an important intrinsic indicator for assessing cell physiology and tissue viability. Dynamic contrast full-field optical coherence tomography (D-FFOCT) is a promising imaging technology that can visualize intracellular movements using the variance of temporal interference signals caused by biological motions. However, double-path interferometry in D-FFOCT can be highly vulnerable to surrounding noise, which may cause turbulence in the interference signals, contaminating the sample dynamics. Therefore, we propose a method for stabilized D-FFOCT imaging in noisy environments by using common-path interferometry in D-FFOCT. A comparative study shows that D-FFOCT with the proposed method achieves stable dynamic contrast imaging of a scattering phantom in motion that is over tenfold more noise-insensitive compared to the conventional one, and thus this imaging capability can provide cleaner motion contrast images. With the proposed approach, the intracellular dynamics of biological samples are imaged and monitored.