Biomed Opt Express
September 2023
Precise segmentation of retinal vessels plays an important role in computer-assisted diagnosis. Deep learning models have been applied to retinal vessel segmentation, but the efficacy is limited by the significant scale variation of vascular structures and the intricate background of retinal images. This paper supposes a cross-channel spatial attention U-Net (CCS-UNet) for accurate retinal vessel segmentation.
View Article and Find Full Text PDFRetinal disease classification is a significant problem in computer-aided diagnosis (CAD) for medical applications. This paper is focused on a 4-class classification problem to automatically detect choroidal neovascularization (CNV), diabetic macular edema (DME), DRUSEN, and NORMAL in optical coherence tomography (OCT) images. The proposed classification algorithm adopted an ensemble of four classification model instances to identify retinal OCT images, each of which was based on an improved residual neural network (ResNet50).
View Article and Find Full Text PDFMicrosc Res Tech
September 2019
Microscopic imaging of uneven surfaces is difficult because of the limited depth of field. In this study, we developed a rapid auto-focus method for uneven surfaces based on image fusion. The Prewitt operator was used to detect the vertical edges of the images.
View Article and Find Full Text PDFPurpose: To compare the choroidal thickness (CT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in preeclamptic, healthy pregnant, and healthy nonpregnant women.
Methods: Studies that focused on the CT evaluation of pregnant women were retrieved by searching PubMed, Embase, Ovid, Cochrane, and Web of Science. We used Stata 14.
The human lens is considered to have a gradient refractive index (GRIN) distribution. The recently developed accommodating volume-constant age-dependent optical (AVOCADO) model can accurately describe the separate GRIN distributions in the axial and radial directions. Our study uses a finite element method to simulate the accommodation process and calculate the GRIN redistribution based on the AVOCADO model for 25-, 35- and 45-year-old lenses.
View Article and Find Full Text PDFPurpose: To evaluate the corneal biomechanical properties of patients who have undergone penetrating keratoplasty (PK) or deep anterior lamellar keratoplasty (DALK) using the ocular response analyzer.
Methods: Stata 13.0 SE was used for this meta-analysis.
Guang Pu Xue Yu Guang Pu Fen Xi
November 2007
Differential optical absorption spectroscopy, or DOAS, is a widely used method to determine concentrations of atmospheric species. The principle of DOAS for measuring the concentration of air pollutants is presented in briefly. Using the linear relationship between the area of the measured differential absorbance curve and that of the differential absorption cross-section curve as taken from the literature, an alternative method for calculating the gas concentration on the basis of the proportionality between differential absorbance and differential absorption cross section of the gas under study was developed.
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