• Title/Summary/Keyword: Fundus spectrum

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Optical Design of a Snapshot Nonmydriatic Fundus-imaging Spectrometer Based on the Eye Model

  • Zhao, Xuehui;Chang, Jun;Zhang, Wenchao;Wang, Dajiang;Chen, Weilin;Cao, Jiajing
    • Current Optics and Photonics
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    • v.6 no.2
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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.

Synchronous Occurrence of a Gastric Adenocarcinoma and a GIST (Gastrointestinal Stromal Tumor): A Case Report (위에 동시성으로 발생한 조기위암 및 위장관간질종양)

  • Jee, Sung-Bae;Seo, Kyung-Jin;Heo, Hun;Jeon, Hae-Myung
    • Journal of Gastric Cancer
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    • v.7 no.4
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    • pp.261-264
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    • 2007
  • A gastric adenocarcinoma is the second most common cause of cancer deaths worldwide, but there are some geographical differences in its incidence. A gastrointestinal tumor is an uncommon disease with a wide spectrum of aggressive behavior. These two tumors have a distinct pathogenesis, and synchronous occurrence of an adenocarcinoma and a GIST (gastrointestinal stromal tumor) in the stomach is very rare. We report a case of synchronous occurrence of a gastric adenocarcinoma and GIST in a 64-year-old man. We performed the following tests: barium swallowing test, gastroduodenoscopy, and CT scanning. We performed a total gastrectomy, and a 9 em-sized GIST at the fundus and a small early gastric cancer at the antrum were confirmed pathologically. Some explanations for this rare case exist, but in our opinion, the synchronous occurrence is a rare but probable event that can happen in an endemic area. We describe a case of synchronous occurrence of a gastric adenocarcinoma and GIST in the stomach, with a review of the literature.

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