• Restorative Dentistry and Endodontics
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• 제36권5호
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• pp.367-376
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• 2011

치아우식증의 조기 발견은 외과적 삭제를 피하면서, 적절한 치료를 할 수 있는 좋은 기회를 제공한다. 광간섭단층촬영술은 최근 각광받기 시작한 3차원 이미지 기술로서, 안과에서 광학적 생검의 목적으로 빈번히 이용되는 것을 필두로 다양한 의학 분야에 적용되어 왔고, 최근 초기 우식증의 발견에 전도유망하여 다양한 연구가 진행 중이다. 이 기술은 저 상관도 간섭계의 원리에 근거하고 있으며, 장점으로는 비침습적이고, 방사선을 사용하지 않으며, 3차원 이미지 구축이 가능하다는 점이다. 본 연구에서는 광간섭단층촬영술의 원리와 개략적인 개발 과정에 대한 기술과 함께 치아우식증에 관한 연구들에 대하여 고찰해 보았고, 이를 통해 이 기술의 응용 가능성을 확인하였다. 그럼에도 불구하고, 임상적인 유용성을 입증하기 위해서는 몇 가지 기술적 문제를 해결해야 하고, 보다 많은 생체 내 실험이 뒷받침되어야 할 것이다.

• Journal of Yeungnam Medical Science
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• 제34권2호
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• pp.279-284
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• 2017

Pulmonary artery sarcoma (PAS) is a rare and fatal disease that often mimics chronic thromboembolic pulmonary hypertension (CTEPH); therefore, diagnosis of PAS is often delayed. Herein, a healthy 74-year-old man was presented with a 4-month history of dyspnea. Chest computed tomography showed wall thickening and stenosis in the main pulmonary artery as well as in both proximal pulmonary arteries. In order to differentiate between unusual CTEPH, vasculitis, and PAS, we performed right heart catheterization and pulmonary angiography. The mean pulmonary arterial pressure was 21 mmHg, and there was severe pulmonary artery stenosis. Thrombi on the pulmonary arterial wall lesions were observed in intravascular ultrasound and optical coherence tomography. Furthermore, the patient had a history of deep vein thrombosis. Therefore, we diagnosed unusual CTEPH. After 6 months of rivaroxaban anticoagulation therapy, a chest X-ray revealed a left lower lobe lung mass, and a positron emission tomography later showed hypermetabolic lesions in the main pulmonary artery wall, in both pulmonary arteries walls, in the lung parenchyma, and in the bones. A biopsy of the right proximal humerus lesion revealed undifferentiated intimal sarcoma. Pulmonary sarcoma is rare, but should be considered when differentially diagnosing main pulmonary artery wall thickening and stenosis. A positron emission tomography may aid in this diagnosis.

• Bioinformatics and Biosystems
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• 제1권1호
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• pp.17-27
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• 2006

Recent progress in the development of non-invasive imaging technologies continues to strengthen the role of molecular imaging biological research. These tools have been validated recently in variety of research models, and have been shown to provide continuous quantitative monitoring of the location(s), magnitude, and time-variation of gene delivery and/or expression. This article reviews the use of radionuclide, magnetic resonance, and optical imaging technologies as they have been used in imaging gene delivery and gene expression for molecular imaging applications. The studies published to date demonstrate that noninvasive imaging tools will help to accelerate pre-clinical model validation as well as allow for clinical monitoring of human diseases.

• 천문학회보
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• 제43권1호
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• pp.68.3-68.3
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• 2018

The MATS (Mesosphere Airglow / Aerosol Tomography Spectroscopy) satellite is a Swedish scientific microsatellite which Kyung Hee University participates in developing. The limb telescope of the MATS satellite is designed with linear astigmatism-free off axis optical configuration which allows wide field of view ($5.67^{\circ}{\times}0.91^{\circ}$). Here we present the full-field optical performance test setup that consists of a point source, a collimator, the limb telescope and a CCD (Charged Coupled Device). The incidence angle of the collimator was carefully controlled by the rotary stage under the limb telescope. The imaging tests represent expected results without dominant aberrations.

• Journal of the Optical Society of Korea
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• 제18권2호
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• pp.151-155
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• 2014

Although various ophthalmic imaging methods, including fundus photography and optical coherence tomography, have been applied for effective diagnosis of ocular diseases with high spatial resolution, most of them are limited by shallow imaging penetration depth and a narrow field of view. Also, many of those imaging modalities are optimized to provide microscopic anatomical information, while functional or cellular information is lacking. Compared to other ocular imaging modalities, photoacoustic imaging can achieve relatively deep penetration depth and provide more detailed functional and cellular data based on photoacoustic signal generation from endogenous contrast agents such as hemoglobin and melanin. In this paper, array-based ultrasound and photoacoustic imaging was demonstrated to visualize pigmentation in the eye as well as overall ocular structure. Fresh porcine eyes were visualized using a real-time ultrasound micro-imaging system and an imaging probe supporting laser pulse delivery. In addition, limited photoacoustic imaging field of view was improved by an imaging probe tilting method, enabling visualization of most regions of the retina covered in the ultrasound imaging.

• Current Optics and Photonics
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• 제1권1호
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• pp.17-22
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• 2017

Mechanical property of tissue is closely related to diseases such as breast cancer, prostate cancer, cirrhosis of the liver, and atherosclerosis. Therefore measurement of tissue mechanical property is important for a better diagnosis. Ultrasound elastography has been developed as a diagnostic modality for a number of diseases that maps mechanical property of tissue. Optical coherence elastography (OCE) has a higher spatial resolution than ultrasound elastography. OCE, therefore, could be a great help for early diagnosis. In this study, we made tissue phantoms and measured their compressive moduli with a rheometer measuring the response to applied force. Uniaxial strain of the tissue phantom was also measured with OCE by using cross-correlation of speckles and compared with the results from the rheometer. In order to compare stiffness of tissue phantoms by OCE, the applied force should be measured in addition to the strain. We, however, did not use a load cell that directly measures the applied force for each sample. Instead, we utilized one silicone film (called as reference phantom) for all OCE measurements that indirectly indicated the amount of the applied force by deformation. Therefore, all measurements were based on displacement, which was natural and effective for image-based elastography such as OCE.

• 한국광학회지
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• 제25권2호
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• pp.67-71
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• 2014

혈관 내 OCT (optical coherence tomography) 는 혈관 벽 내부의 3차원적 미세구조를 영상화할 수 있어서 임상에서 각광을 받고 있다. 하지만 아직도 충분하지 못한 이미징 속도, 특히 내시경 프로브의 이미징 광 스캐닝 속도의 부족으로 혈관 길이 방향의 이미징 간격이 실제 시스템의 광학적 해상도보다 5배 이상 커서 혈관 종방향으로의 고해상도 이미징이 얻어지지 못하고 있는 상황이다. 본 논문에서는 초당 350장의 혈관 벽 단층 영상을 제공하는 고속 혈관 내 OCT 시스템을 기술한다. 본 시스템과 내시경 장치를 이용하여 47 mm 길이의 살아있는 토끼 대동맥을 3.7초만에 34 micron의 혈관 종방향 간격으로 얻는데 성공하였다. 34 micron의 종방향 간격은 실제 내시경의 그 방향 광학적 해상도와 비슷한 정도로서 3차원 모든 방향으로의 고해상도 이미징을 구현하였음을 보여준다. 얻어진 이미징 데이터의 3차원 영상 구현을 통해 혈관의 미세구조 및 이미징 전 삽입된 스텐트의 자세한 구조를 보였다.

• 한국산학기술학회논문지
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• 제22권2호
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• pp.134-138
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• 2021

스마트폰 등에서 사용되는 고성능 디스플레이에는 다양한 종류의 정밀한 플라스틱 박막 필름(Plastic Thin Film)이 사용되고 있다. 롤투롤(Roll-To-Roll) 공정으로 제조되는 플라스틱 박막 필름은 생산 공정 중에 실시간으로 필름의 두께가 계측되고, 정확하게 관리되어야 한다. 필름 제조 과정에서 필름에 장력이 작용하면서 주름이 발생되고, 이러한 주름 발생은 필름의 두께 방향과 두께 측정기의 광축이 서로 경사지게 한다. 결국 두께 측정기는 필름의 수직 두께가 아닌 경사진 두께를 측정하게 됨으로써 실제 두께보다 더 큰 값으로 측정하게 된다. 본 연구에서는, 플라스틱 필름의 경사로 인하여 발생하게 되는 두께 측정기에서의 계측값 오차를 보정하기 위하여, 필름의 경사 각도를 계측하는 연구가 진행되었다. 플라스틱 필름에 슬릿 빔 레이저를 조사하고, 필름에서 반사되는 슬릿 빔 레이저가 PSD(Position Sensitive Device)에 맺히는 광학 시스템을 구성하였으며, 실험을 통하여 필름의 경사 각도와 PSD 출력값의 관계를 1차 방정식 형태로 구하였다. 이를 이용하여 필름의 경사 각도를 측정하는 장치가 구축되었으며, 250KHz의 속도로 경사 각도의 측정이 가능하였다.

• Journal of Veterinary Science
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• 제24권4호
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• pp.34.1-34.12
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• 2023

Background: There has not been a thoroughly reported study of the comparison between spectral domain-optical coherence tomography (SD-OCT) with both ultrasound biomicroscopy (UBM) and gonioscopy on the evaluation of the iridocorneal angle (ICA) in dogs. Objectives: To investigate the diagnostic value of SD-OCT for the early detection of narrowing ICA by comparing and assessing inter-device agreement in anterior chamber angle (ACA) measurements obtained by SD-OCT and UBM, and ICA evaluations by gonioscopy. Methods: A total of 28 eyes from 28 client-owned dogs with normal intraocular pressure were included for examination. The ACA and angle opening distance (AOD) were measured from the SD-OCT and UBM images, and gonioscopy images were analyzed using the ICA grade and ZibWest angle index. Results: The mean ACA and AOD for SD-OCT were 28.31° ± 5.37° and 658.42 ± 219.90 ㎛, and for UBM, 28.34° ± 5.82° and 859.29 ± 221.80 ㎛, respectively. The mean difference in ACA between the average values of SD-OCT and UBM measurements was 0.03° with a 95% limit of agreement (LoA) span of 16.2°, indicating positive agreement; that in AOD was 200.85 ㎛ with a 95% LoA span of 1,110.95 ㎛, indicating poor agreement. The Pearson correlation coefficient of the ACA of SD-OCT and ZibWest indices of gonioscopy was 0.624, indicating strong agreement; that of UBM and gonioscopy was 0.43, indicating moderate agreement. Conclusions: SD-OCT is well tolerated by canine patients due to its non-contact method and might be an alternative option for early screening of ICA narrowing in clinical settings.

• 한국전기전자재료학회논문지
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• 제26권3호
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• pp.183-189
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• 2013

The chalcogenide glass has superior optical properties in IR region transmittances. We have determined the composition of GeSbSe chalcogenide glass for the application of good IR lenses, resulting in the composite rate of $Ge_{19}Sb_{23}Se_{58}$. The optical, structural, thermal and physical properties were measured by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Differential scanning calorimeter (DSC), X-ray computed tomography (X-ray CT) respectively. The fabrication of the chalcogenide glass lens for infrared optics applications was proposed using a diamond turning machining technology which is known as the suitable ways for the production cost reduction and the accurate fabrication process control.