• Journal of the Korean Applied Science and Technology
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• v.28 no.1
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• pp.102-108
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• 2011

The study of wave propagation and scattering in biological media has become increasingly important in recent years. The propagation of light within tissues is an important problem that confronts the dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. In the clinical application of photodynamic therapy(PDT) and in photobiology, the photon deposition within a tissue determines the spatial distribution of photochemical reactions. Scattered light is measured as a function of the distance (r) between the axis of the incident beam and the detection spot. Consequently, knowledge of the photosensitizer(Chlorophyll-a) function that characterizes a phantom is measured. To obtain the results of scattering coefficients(${\mu}s$) of a turbid material from diffusion described by experimental approach. It was measured the energy fluency of photon radiation at the position of penetration depth. From fluorescence experimental method obtained the analytical expression for the scattered light as the values of $(I/I_o)_{wavelength}$ vs the distance between the center of the incident beam and optical fiber in terms of the condition of "in situ spectroscopy(optically thick)" and real time by fluorometric measurements. The result was compromised with transport of intensities though a random distribution of scatters.

• Journal of the Korean Applied Science and Technology
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• v.22 no.2
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• pp.182-190
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• 2005

The propagation of light radiation within tissues is an important problem that confronts the dosimetry of therapeutic laser delivery and the development of diagnostic spectroscopy. In the clinical application of photodynamic therapy(PDT) and in photobiology, the photon deposition within a tissue determines the spatial distribution of photochemical reactions. Scattered light is measured as a function of the distance (r) between the axis of the incident beam and the detection spot. Consequently, knowledge of the photosensitizer(Chlorophyll-a) function that characterizes a phantom is important. To obtain the results of scattering coefficients(${\mu}s$) of a turbid material from diffusion described by experimental approach. It was measured the energy fluency of photon radiation at the position of penetration depth. From fluorescence experimental method obtained the analytical expression for the scattered light as the values of $(I\;/I_o)_{wavelength}$ vs the distance between the center of the incident beam and optical fiber in terms of the condition of "in situ spectroscopy(optically thick)" and real time by fluorometric measurements.

• Current Optics and Photonics
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• v.5 no.3
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• pp.311-321
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• 2021

Indocyanine green (ICG) is a dye approved for use in clinical diagnostics. ICG remains in the intravascular space following intravenous administration, due to its ability to rapidly bind to the plasma proteins, and its therapeutic potential has been studied in well-vascularized cutaneous tumors. Here we have evaluated the clinical response of a subconjunctival tumor to photothermal therapy (PTT) using an ICG-enhanced near-infrared diode laser and its adverse effects, in a rabbit. 22 male New Zealand white rabbits with subconjunctival tumors were enrolled (control group 6, laser-only group 8, laser-with-ICG group 8). Rabbits in the laser-with-ICG group received ICG (twice, 2 mg/kg each time, intravenously) directly followed by irradiation with a diode laser (λ = 810 nm). Rabbits in the laser-only group were irradiated with the diode laser. ICG angiography, ultrasonography, and pathologic examination were performed to evaluate PTT response at specific time points (0, 2, and 4 weeks after PTT). Two weeks after initial treatment, the eight rabbits treated by laser with ICG showed a 100% response rate. There was no clinical response in both laser-only and control groups. ICG-PTT is a potential and effective palliative therapeutic modality for subconjunctival tumors.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.925-932
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• 2019

In this paper, we developed optical dosimetry system with a plastic scintillator, a commercial 50 mm, f1.8 lens, and a commercial high-sensitivity CMOS (complementary metal-oxide semiconductor) camera. And, the correction processors of vignetting, geometrical distortion and scaling were established. Using the developed system, we can measured a percent depth dose, a beam profile and a dose linearity for 6 MV medical LINAC (Linear Accelerator). As results, the optically measured percent depth dose was well matched with the measured percent depth dose by ion-chamber within 2% tolerance. And the determined flatness was 2.8%. We concluded that the optical dosimetry system was sufficient for application of absorbed dose monitoring during radiation therapy.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1141-1146
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• 2003

In order to investigate different and original theories on pathology of eyes from the past main etiology of fire and heat, two texts of Si-sheng-xin-yuan written by Huang Yuan Yu and Eui-gam-jung-ma written by Lee Gyu Jun are selected and analysed in terms of pathology and prescription. Huang explained that diseases of the eyes are usually born of functional disorders of spleen and stomach(脾胃升降失調) accompanied with turbidity change of energy and blood(氣血淸濁變化). In the meantime, Lee described that the diseases are made from disorders of activities of essence, spirit, energy and blood stored in 5 viscera. So following them, the main point of treatment for the diseases of eyes is to restore and clarify the stagnated gastrointestinal(GI) function, or to supply the clear essence and blood to eyes respectively. Also they have same opinions that the fire and heat are the secondary symptoms of the optical diseases. Therefore Huang focused on cleaning the phlegm and leaking the moisture of GI tract to treat those symptoms, and Lee emphasized on nourishing essential energy of kidney and liver on the other hand. Although they preferred to use radical therapy than symptomatic one. But it can be deduced that Huang's theory is more positive and direct therapy and Lee's one is more basic but indirect treatment.

• BMB Reports
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• v.55 no.6
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• pp.267-274
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• 2022

Molecular imaging is used to improve the disease diagnosis, prognosis, monitoring of treatment in living subjects. Numerous molecular targets have been developed for various cellular and molecular processes in genetic, metabolic, proteomic, and cellular biologic level. Molecular imaging modalities such as Optical Imaging, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), Single Photon Emission Computed Tomography (SPECT), and Computed Tomography (CT) can be used to visualize anatomic, genetic, biochemical, and physiologic changes in vivo. For in vivo cell imaging, certain cells such as cancer cells, immune cells, stem cells could be labeled by direct and indirect labeling methods to monitor cell migration, cell activity, and cell effects in cell-based therapy. In case of cancer, it could be used to investigate biological processes such as cancer metastasis and to analyze the drug treatment process. In addition, transplanted stem cells and immune cells in cell-based therapy could be visualized and tracked to confirm the fate, activity, and function of cells. In conventional molecular imaging, cells can be monitored in vivo in bulk non-invasively with optical imaging, MRI, PET, and SPECT imaging. However, single cell imaging in vivo has been a great challenge due to an extremely high sensitive detection of single cell. Recently, there has been great attention for in vivo single cell imaging due to the development of single cell study. In vivo single imaging could analyze the survival or death, movement direction, and characteristics of a single cell in live subjects. In this article, we reviewed basic principle of in vivo molecular imaging and introduced recent studies for in vivo single cell imaging based on the concept of in vivo molecular imaging.

• The Korean Journal of Nuclear Medicine
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• v.36 no.1
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• pp.74-79
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• 2002

In addition to the well-established use of positron emission tomography (PET) in clinical oncology, novel roles for PET are rapidly emerging in the field of gene therapy. Methods for controlled gene delivery to living bodies, made available through advances in molecular biology, are currently being employed in animals for research purposes and in humans to treat diseases such as cancer. Although gene therapy is still in its early developmental stage, it is perceived that many serious illnesses could be treated successfully by the use of therapeutic gene delivery. A major challenge for the widespread use of human gene therapy is to achieve a controlled and effective delivery of foreign genes to target cells and subsequently, adequate levels of expression. As such, the availability of noninvasive imaging methods to accurately assess the location, duration, and level of transgene expression is critical for optimizing gene therapy strategies. Current endeavors to achieve this goal include methods that utilize magnetic resonance imaging, optical imaging, and nuclear imaging techniques. As for PET, reporter systems that utilize genes encoding enzymes that accumulate positron labeled substrates and those transcribing surface receptors that bind specific positron labeled ligands have been successfully developed. More recent advances in this area include improved reporter gene constructs and radiotracers, introduction of potential strategies to monitor endogenous gene expression, and human pilot studies evaluating the distribution and safety of reporter PET tracers. The remarkably rapid progress occurring in gene imaging technology indicates its importance and wide range of application. As such, gene imaging is likely to become a major and exciting new area for future application of PET technology.

• Korean Journal of Optics and Photonics
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• v.17 no.4
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• pp.312-316
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• 2006

In this study, a miniature fiber-optic radiation sensor has been developed using a water-equivalent organic scintillator for electron beam therapy dosimetry. The intensity of Cerenkov light is measured and characterized as a function of the incident angle of the electron beam from a LINAC. Also, a subtraction method using a background optical fiber without a scintillator and an optical discrimination method using optical filters are investigated to remove Cerenkov light, which could cause problems or limit the accuracy for detecting a fluorescent light signal in a fiber-optic radiation sensor.

• Korean Journal of Digital Imaging in Medicine
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• v.12 no.1
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• pp.59-64
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• 2010

We examined the accuracy and efficiency of phantom by applying the designed phantom in order to check daily quality assurance easily by objective criteria and to confirm daily quality assurance of linear accelerator, simulator, and CT-simulator. The results of 10 weeks of linear accelerator output dose using American Association of Physicists in Medicine(AAPM) daily quality assurance guide were measured within ${\pm}1%$ of error. Mechanical check of laser alignment, optical distance indicator(ODI), CT scanner laser and alignment of gantry lasers with the center of imaging plane were measured within ${\pm}1mm$. Daily average working time for daily quality assurance of radiation therapy equipments was 38 minutes. The designed phantom was easy to install and daily quality assurance was possible with only one installation. The aspects reproducibility and efficiency as well as accuracy of quality assurance were excellent.

• International journal of advanced smart convergence
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• v.6 no.1
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• pp.18-25
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• 2017

Recently, VR HMD (virtual reality head mounted display) has been utilized for virtual training, entertainment, vision therapy, and optometry. In particular, virtual reality contents are increasingly used for vision therapy and optometry. Accordingly, high-quality virtual reality contents such as a natural vision of life is required. Therefore, it is necessary to study the content production according to the optical characteristics of the VR HMD. The purpose of this paper is to suggest a proper FOV (field of view) of contents according to the distortion rate. We produced virtual reality contents and obtained distorted images by virtual camera. The distortion rate is calculated by using the distorted image. It is proved that the optimal FOV of the VR content with the minimum distortion is $90{\sim}100^{\circ}$. The results of this study are expected to be applied to the production of high quality contents.