• Applied Microscopy
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• 제46권1호
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• pp.6-13
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• 2016

Fluorescence lifetime imaging microscopy (FLIM) has been considered an effective technique to investigate chemical properties of the specimens, especially of biological samples. Despite of this advantageous trait, researchers in this field have had difficulties applying FLIM to their systems because acquiring an image using FLIM consumes too much time. Although analog mean-delay (AMD) method was introduced to enhance the imaging speed of commonly used FLIM based on time-correlated single photon counting (TCSPC), a real-time image reconstruction using AMD method has not been implemented due to its data processing obstacles. In this paper, we introduce a real-time image restoration of AMD-FLIM through fast parallel data processing by using Threading Building Blocks (TBB; Intel) and octa-core processor (i7-5960x; Intel). Frame rate of 3.8 frames per second was achieved in $1,024{\times}1,024$ resolution with over 4 million lifetime determinations per second and measurement error within 10%. This image acquisition speed is 184 times faster than that of single-channel TCSPC and 9.2 times faster than that of 8-channel TCSPC (state-of-art photon counting rate of 80 million counts per second) with the same lifetime accuracy of 10% and the same pixel resolution.

• Current Optics and Photonics
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• 제5권5호
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• pp.554-561
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• 2021

Indocyanine green (ICG) is a cyanine dye that has been used in medical diagnostics based on fluorescence imaging, and in medical therapy based on the photothermal effect. It is important to systematically understand the photothermal effect and fluorescence characteristics of ICG simultaneously. By varying a number of conditions such as laser power density, laser irradiation wavelength, concentration of ICG solution, and exposure time of laser irradiation, the intensity properties of fluorescence and the temperature change induced by the photothermal effect are measured simultaneously using a charge-coupled-device camera and a thermal-imaging camera. The optimal conditions for maximizing the photothermal effect are determined, while maintaining a relatively long lifetime and high efficiency of the fluorescence for fluorescence imaging. When the concentration of ICG is approximately 50 ㎍/ml and the laser power density exceeds 1.5 W/cm², the fluorescence lifetime is the longest and the temperature induced by the photothermal effect rapidly increases, exceeding the critical temperature sufficient to damage human cells and tissues. The findings provide useful insight into the realization of effective photothermal therapy, while also specifying the site to be treated and enabling real-time treatment monitoring.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2002년도 정기총회 및 제9회 광과학 학술심포지움 논문초록
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• pp.34-34
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• 2002

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.477-478
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• 2006

• 대한화학회지
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• 제68권1호
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• pp.54-56
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• 2024

• 한국음향학회지
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• 제42권5호
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• pp.429-440
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• 2023

이 연구는 초음파 광학 영상 기반의 다중 모달 영상 기술에 대한 최신 연구 동향과 응용 가능성에 대해 조사하였다. 초음파 영상은 실시간 영상 기능을 가지고 있으며 인체에 상대적으로 안전한 특성으로 인해 의료 분야에서 다양한 질병의 진단에 사용되고 있다. 그러나 초음파 영상은 해상도가 낮은 한계가 있어 진단 정확도를 향상시키기 위해 다른 광학 영상과의 결합을 통한 다중 모달 영상 기술 개발 연구가 진행되고 있다. 특히 초음파 광학 영상 기반의 다중 모달 영상 기술은 각각의 영상 기법의 장점을 극대화하고 단점을 보완함으로써 질병 진단 정확도를 향상시킬 수 있는 수단으로 사용되고 있다. 이러한 기술은 초음파의 실시간 영상 기능과 광간섭 단층 영상 융합 기술, 초음파 광음향 다중 모달 영상 기술, 초음파 형광 다중 모달 영상 기술, 초음파 형광 시정수 다중 모달 영상 기술 및 초음파 분광 다중 모달 영상 기술 등 다양한 형태로 제안되고 있다. 본 연구에서는 이러한 초음파 광학 영상 기반의 다중 모달 영상 기술의 최신 연구 동향을 소개하고, 의학 및 바이오 분야에서의 응용 가능성을 조사하였다. 이를 통해 초음파와 광학 기술의 융합이 어떻게 진행되고 있는지에 대한 통찰력을 제공하고, 의료 분야에서의 진단 정확도 향상을 위한 새로운 접근 방식에 대한 기반을 마련하였다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2253-2260
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• 2007

A series of tetra donor substituted [2.2]paracyclophane-based two-photon absorption (TPA) fluorophores were synthesized in neutral and cationic forms. The imaging activity of overall set of fluorophores was studied by the two-photon induced fluorescence (TPIF) method in a range of solvents. We also measured a clear progression toward a longer photoluminescence lifetime with increasing solvent polarity (intrinsic photoluminescence lifetime, τi: ~2 ns in toluene → 12-16 ns in water). The paracyclophane fluorophores with this unique property can be utilized as an optical polarity probe for the biomolecular substrates. The combined measurement of the two-photon fluorescence microscopy (TPM) cell image and TPIF lifetime can give us a better understanding of the biological processes and local environments in the cells.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 창립 20주년기념 특별학술발표회
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• pp.199-200
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• 2009