• Investigative Magnetic Resonance Imaging
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• 제25권4호
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• pp.218-228
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• 2021

Due to their high degree of freedom to transfer and acquire light, fiber optics can be used in the presence of strong magnetic fields. Hence, optical sensing and imaging based on fiber optics can be integrated with magnetic resonance imaging (MRI) diagnostic systems to acquire valuable information on biological tissues and organs based on a magnetic field. In this article, we explored the combination of MRI and optical sensing/imaging techniques by classifying them into the following topics: 1) functional near-infrared spectroscopy with functional MRI for brain studies and brain disease diagnoses, 2) integration of fiber-optic molecular imaging and optogenetic stimulation with MRI, and 3) optical therapeutic applications with an MRI guidance system. Through these investigations, we believe that a combination of MRI and optical sensing/imaging techniques can be employed as both research methods for multidisciplinary studies and clinical diagnostic/therapeutic devices.

• 한국안광학회지
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• 제12권3호
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• pp.143-149
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• 2007

본 논문에서는 한국, 미국과 유럽연합의 의료기기의 정의, 분류, 안경테를 다루는 직종, 관리, 판매 등에 대하여 비교 분석하였다. 한국은 시력보정용 안경테를 공산품으로 지정한 반면 유럽연합과 미국은 의료기기로 분류하였다. 선글라스의 경우 한국과 유럽연합에서는 공산품이지만 미국에서는 의료기기이다. 안경테와 선글라스의 공산품 지정은 여러 가지 문제점을 유발한다. 시력보정용 안경테와 선글라스의 의료기기지정은 이러한 문제를 해결할 수 있을 것으로 본다.

• 한국안광학회지
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• 제1권1호
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• pp.41-51
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• 1996

안경은 벗으면 일종의 광학기구이나, 착용하면 안광학계와 합성광학계를 이루어 시력을 교정한다. 이때 시력교정용 안경테는 렌즈와 눈으로 조합된 광학계의 기능을 조정하는 보조적 역할을 하여 시기능교정에 영향을 미친다. 안경테를 잘못 선택할 경우, 시기능교정에 제약을 받게되며 더 나아가서는 새로운 굴절이상이나 안위이상을 일으켜 안정피로는 물론 시력저하를 초래할 가능성도 있다. 그래서, 전문지식을 갖춘 안경사가 안경테를 선택하고 조정해야만되는 당위성을 본고를 통해 고찰한다.

• 한국안광학회지
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• 제12권4호
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• pp.9-14
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• 2007

본 논문에서는 매년 증가되는 안경광학과 입학정원 증가에 따른 문제점들을 연구하였다. 주된 문제는 안경사 인력의 과잉공급과 열악한 근무환경에 기인하며 이를 해결하기 위해서는 안경사 인력의 수적 불균형을 해소하겠다는 관계자 모두의 공통된 정책적 시각을 가져야 한다. 또 보건의료 인력의 수요와 공급을 예측하고 정확한 정책을 수립하기 위해서는 보건의료 인력개발을 담당할 상설기구와 중장기적인 계획이 필요하다. 안경사 인력의 질적 불균형의 해소를 위해서는 정확한 직무 영역을 설정하고 전문교육과정을 재편하며 국가고시 실기평가의 방법을 구체화하며 보수교육의 내용과 방법을 혁신해 가야 한다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1991년도 춘계학술대회
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• pp.9-12
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• 1991

The correlation search method yields velocity information by tracking scatter patterns between medical image frames. The displacement vector between a target region and the best correlated search region indicates the magnitude and direction of the inter-frame motion of that particular region. However, if the noise sources in the target region and the search region are correlated Gaussian, then the cross-correlation technique fails to work well because it estimates the cross-correlation of both signals and noises. In this paper we develop a new correlation search method which seeks the best correlated third-order statistics between a target and the search region to suppress the effect of correlated Gaussian noise sources. Our new method yields better estimations of velocity than the conventional cross-correlation method.

• Current Optics and Photonics
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• 제6권6호
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• pp.550-564
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• 2022

Optical microscopy is a useful tool for study in the biological sciences. With an optical microscope, we can observe the micro world of life such as tissues, cells, and proteins. A fluorescent dye or a fluorescent protein provides an opportunity to mark a specific target in the crowd of biological samples, so that an image of a specific target can be observed by an optical microscope. The optical microscope, however, is constrained in resolution due to diffraction limit. Super-resolution microscopy made a breakthrough with this diffraction limit. Using a super-resolution microscope, many biomolecules are observed beyond the diffraction limit in cells. In the case of volumetric imaging, the super-resolution techniques are only applied to a limited area due to long imaging time, multiple scattering of photons, and sample-induced aberration in deep tissue. In this article, we review recent advances in super-resolution microscopy for volumetric imaging. The super-resolution techniques have been integrated with various modalities, such as a line-scan confocal microscope, a spinning disk confocal microscope, a light sheet microscope, and point spread function engineering. Super-resolution microscopy combined with adaptive optics by compensating for wave distortions is a promising method for deep tissue imaging and biomedical applications.

• Current Optics and Photonics
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• 제6권2호
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• pp.151-160
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• 2022

Fundus images can reflect ocular diseases and systemic diseases such as glaucoma, diabetes mellitus, and hypertension. Thus, research on fundus-detection equipment is of great importance. The fundus camera has been widely used as a kind of noninvasive detection equipment. Most existing devices can only obtain two-dimensional (2D) retinal-image information, yet the fundus of the human eye also has spectral characteristics. The fundus has many pigments, and their different distributions in the eye lead to dissimilar tissue penetration for light waves, which can reflect the corresponding fundus structure. To obtain more abundant information and improve the detection level of equipment, a snapshot nonmydriatic fundus imaging spectral system, including fundus-imaging spectrometer and illumination system, is studied in this paper. The system uses a microlens array to realize snapshot technology; information can be obtained from only a single exposure. The system does not need to dilate the pupil. Hence, the operation is simple, which reduces its influence on the detected object. The system works in the visible and near-infrared bands (550-800 nm), with a volume less than 400 mm × 120 mm × 75 mm and a spectral resolution better than 6 nm.

• 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.

• 한국전기전자재료학회논문지
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• 제26권8호
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• pp.624-628
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• 2013

With the recent development of less-costly uncooled detector technology, expensive optics are among the remaining significant cost drivers in the thermography camera. As a potential solution to this problem, the fabrication of IR lenses using chalcogenide glass has been studied in recent years. We report on the molding and evaluation of a ultra-precision chalcogenide-glass lens for the thermography camera for body-temperature monitoring. In addition, we fabricated prototype thermography camera using the chalcogenide-glass lens and obtained the thermal image from the camera. In this work, it was found out that thermography camera discerned body-temperature between 20 and $50^{\circ}C$ through the analysis of thermal image. It is confirmed that thermography camera using the chalcogenide-glass lens is applicable to the body-temperature monitoring system.

• Current Optics and Photonics
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• 제5권4호
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• pp.402-408
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• 2021

An off-axis system refers to an optical system in which the optical axis and normal vector at the vertex of each surface do not match. The most important specification in an optical system is its focal length. Among the various methods for measuring the focal length, the most suitable method for the off-axis system is the method that adopts magnification. However, head-mounted display (HMD) optics must be measured while considering the virtual image distance, which is not infinity owing to product characteristics. For the virtual image distance, a camera with a focusing function was used. By measuring HMD optics via this magnification method, the error generated in this measurement was 0.68% of the HMD's focal length, which is within the 1%-3% range of the conventionally permitted design error for the focal length allowed at the optical design stage. Therefore, it can be verified that the measurement accuracy of the method proposed in this study is sufficiently feasible in practice.