Purpose: The aim of this study is early detection of increased cup to disc ratio and a survey study of cup-disc ratio in Egyptian children age group less than 15 years. Methods: Three hundred and eighty-two (382) chil...Purpose: The aim of this study is early detection of increased cup to disc ratio and a survey study of cup-disc ratio in Egyptian children age group less than 15 years. Methods: Three hundred and eighty-two (382) children were enrolled in this study. They were classified into three age groups;infants’ Group (1) from 0-2 years, preschool Group (2) from 2-6 years and school children Group (3) from 6-15 years old. C/D ratio was measured for each child. Results: In Group (1), normal C/D ratio ranged from 0 to 0.1. The C/D ratio > 0.3 or a binocular difference of >0.2 could be regarded as one of the criteria of newborn glaucoma. Group (2): the normal ratio ranged from 0.1-0.2. Group (3): the normal ratio ranged from 0.2-0.3. The highest ratio 0.7 was found in two eyes. An asymmetry of 0.2 or more in the C/D ratios of the eyes was found in 4.8% of the children. Conclusion: C/D ratio > 0.3 and asymmetry of 0.2 is suggestive of glaucoma especially in infants of lower age group.展开更多
Purpose: To investigate the difference of stereometric parameters of optic nerve head between the normal subjects and patients with big-cupped disk and primary open angle glaucoma (POAG).Methods: Twenty-two cases (44 ...Purpose: To investigate the difference of stereometric parameters of optic nerve head between the normal subjects and patients with big-cupped disk and primary open angle glaucoma (POAG).Methods: Twenty-two cases (44 eyes) of normal subjects, 17 cases (34 eyes) of patients with big-cupped disk and 19 cases (37 eyes) of patients with POAG underwent Heidelberg Retina Tomograph (HRT) examination to get topography images and stereometric parameters of optic nerve head.Results: The stereometric parameters of optic nerve head of the normal, patients with big-cupped disk and POAG were 1) disk area (mm2): 1. 995± 0. 501, 2. 407±0. 661 and 2. 248±0.498; 2) cup area (mm2): 0.573±0.264, 1. 095±0. 673 and 1. 340±0. 516; 3) cup/disk ratio: 0. 25±0. 095, 0. 428±0. 176 and 0. 589±0.195; 4) rim area (mm2): 1.461±0.328, 1.312±0.418 and 0. 905± 0.409; 5)cup volume (mm3): 0. 108±0. 073, 0. 347±0. 346 and 0. 550 ±0. 394; 6) rim volume (mm3): 0. 421±0. 111, 0. 378±0. 225 and 0. 224±0. 189; 7) mean cup展开更多
In this work,we aim to introduce some modifications to the Anam-Net deep neural network(DNN)model for segmenting optic cup(OC)and optic disc(OD)in retinal fundus images to estimate the cup-to-disc ratio(CDR).The CDR i...In this work,we aim to introduce some modifications to the Anam-Net deep neural network(DNN)model for segmenting optic cup(OC)and optic disc(OD)in retinal fundus images to estimate the cup-to-disc ratio(CDR).The CDR is a reliable measure for the early diagnosis of Glaucoma.In this study,we developed a lightweight DNN model for OC and OD segmentation in retinal fundus images.Our DNN model is based on modifications to Anam-Net,incorporating an anamorphic depth embedding block.To reduce computational complexity,we employ a fixed filter size for all convolution layers in the encoder and decoder stages as the network deepens.This modification significantly reduces the number of trainable parameters,making the model lightweight and suitable for resource-constrained applications.We evaluate the performance of the developed model using two publicly available retinal image databases,namely RIM-ONE and Drishti-GS.The results demonstrate promising OC segmentation performance across most standard evaluation metrics while achieving analogous results for OD segmentation.We used two retinal fundus image databases named RIM-ONE and Drishti-GS that contained 159 images and 101 retinal images,respectively.For OD segmentation using the RIM-ONE we obtain an f1-score(F1),Jaccard coefficient(JC),and overlapping error(OE)of 0.950,0.9219,and 0.0781,respectively.Similarly,for OC segmentation using the same databases,we achieve scores of 0.8481(F1),0.7428(JC),and 0.2572(OE).Based on these experimental results and the significantly lower number of trainable parameters,we conclude that the developed model is highly suitable for the early diagnosis of glaucoma by accurately estimating the CDR.展开更多
Prandtl-Reuss flow rule and Hill’s yield criterion were adopted and combined with the concept of finite deformation theory, updated Lagrangian formulation, and a three-dimensional finite element analytical model was ...Prandtl-Reuss flow rule and Hill’s yield criterion were adopted and combined with the concept of finite deformation theory, updated Lagrangian formulation, and a three-dimensional finite element analytical model was established by application of quadrilateral four-node degenerated shell elements coupling into a rigid matrix to deal with the sheet metal forming problems. The fractured thickness of a specimen obtained from a simple tension test was used to be the fracture criterion for the numerical analysis to explore the relationship between punch load and stroke, the thickness distribution, the deformation history and the forming limit of work-piece in the elliptical cup drawing process. The numerical analysis and experiment results show that the punch load increases with the increase of punch stroke, and when the load reaches its maximum, the blank continues to deform with the increase of the punch stroke, resulting in a reduced load until the extension is completed. The minimum thickness of the work-piece concentrates in the contact region of the work-piece and long axis of the punch due to the smaller radius of the curvature of the long axis than the short axis. So the blanks bore the maximum tensile stress in the long axis. Through the limit drawing ratio defined by perimeter of the elliptical punch, the limit drawing ratio of this elliptical cup drawing is defined to be 2.136.展开更多
The unsteady, laminar, incompressible, and two-dimensional flow of a mi- cropolar fluid between two orthogonally moving porous coaxial disks is considered. The extension of von Karman＇s similarity transformations is ...The unsteady, laminar, incompressible, and two-dimensional flow of a mi- cropolar fluid between two orthogonally moving porous coaxial disks is considered. The extension of von Karman＇s similarity transformations is used to reduce the governing partial differential equations （PDEs） to a set of non-linear coupled ordinary differential equations （ODEs） in the dimensionless form. The analytical solutions are obtained by employing the homotopy analysis method （HAM）. The effects of various physical param- eters such as the expansion ratio and the permeability Reynolds number on the velocity fields are discussed in detail.展开更多
Purpose: The main objective was to analyze the relationship between maximum cup depth (MCD), mean defect (MD), central corneal thickness (CCT), age and disc area, in patients with ocular hypertension (OHT) and primary...Purpose: The main objective was to analyze the relationship between maximum cup depth (MCD), mean defect (MD), central corneal thickness (CCT), age and disc area, in patients with ocular hypertension (OHT) and primary open angle glaucoma (POAG). Methods: Cross-sectional study of patients diagnosed with OHT and POAG. Visual fields were obtained using an Octopus 300 analyzer, TOP strategy. MCD and disc area were obtained using a Heidelberg Retina Tomograph. Results: The study sample comprised 234 eyes of 143 patients, 91 women and 52 men, mean age 63.55 years (SD 10.49). Mean values were: MCD 0.52 mm (SD 0.27), MD 2.78 dB (SD 5.02), CCT 543.5 μm (SD 36.63), IOP 16.73 mmHg (SD 2.93), and disc area 2.01 mm<sup>2</sup> (SD 0.39). A significant correlation was observed between MCD and age in patients under 60 years, between MCD and disc area, and between MD and disc area. Conclusions: Our study showed a correlation between MCD and age which was significant in patients under 60 years of age, between MCD and disc area and between MD and disc area, suggesting that the larger the disc area, the greater the MCD and the MD in patients with OHT and POAG.展开更多
文摘Purpose: The aim of this study is early detection of increased cup to disc ratio and a survey study of cup-disc ratio in Egyptian children age group less than 15 years. Methods: Three hundred and eighty-two (382) children were enrolled in this study. They were classified into three age groups;infants’ Group (1) from 0-2 years, preschool Group (2) from 2-6 years and school children Group (3) from 6-15 years old. C/D ratio was measured for each child. Results: In Group (1), normal C/D ratio ranged from 0 to 0.1. The C/D ratio > 0.3 or a binocular difference of >0.2 could be regarded as one of the criteria of newborn glaucoma. Group (2): the normal ratio ranged from 0.1-0.2. Group (3): the normal ratio ranged from 0.2-0.3. The highest ratio 0.7 was found in two eyes. An asymmetry of 0.2 or more in the C/D ratios of the eyes was found in 4.8% of the children. Conclusion: C/D ratio > 0.3 and asymmetry of 0.2 is suggestive of glaucoma especially in infants of lower age group.
文摘Purpose: To investigate the difference of stereometric parameters of optic nerve head between the normal subjects and patients with big-cupped disk and primary open angle glaucoma (POAG).Methods: Twenty-two cases (44 eyes) of normal subjects, 17 cases (34 eyes) of patients with big-cupped disk and 19 cases (37 eyes) of patients with POAG underwent Heidelberg Retina Tomograph (HRT) examination to get topography images and stereometric parameters of optic nerve head.Results: The stereometric parameters of optic nerve head of the normal, patients with big-cupped disk and POAG were 1) disk area (mm2): 1. 995± 0. 501, 2. 407±0. 661 and 2. 248±0.498; 2) cup area (mm2): 0.573±0.264, 1. 095±0. 673 and 1. 340±0. 516; 3) cup/disk ratio: 0. 25±0. 095, 0. 428±0. 176 and 0. 589±0.195; 4) rim area (mm2): 1.461±0.328, 1.312±0.418 and 0. 905± 0.409; 5)cup volume (mm3): 0. 108±0. 073, 0. 347±0. 346 and 0. 550 ±0. 394; 6) rim volume (mm3): 0. 421±0. 111, 0. 378±0. 225 and 0. 224±0. 189; 7) mean cup
基金funded byResearchers Supporting Project Number(RSPD2024R 553),King Saud University,Riyadh,Saudi Arabia.
文摘In this work,we aim to introduce some modifications to the Anam-Net deep neural network(DNN)model for segmenting optic cup(OC)and optic disc(OD)in retinal fundus images to estimate the cup-to-disc ratio(CDR).The CDR is a reliable measure for the early diagnosis of Glaucoma.In this study,we developed a lightweight DNN model for OC and OD segmentation in retinal fundus images.Our DNN model is based on modifications to Anam-Net,incorporating an anamorphic depth embedding block.To reduce computational complexity,we employ a fixed filter size for all convolution layers in the encoder and decoder stages as the network deepens.This modification significantly reduces the number of trainable parameters,making the model lightweight and suitable for resource-constrained applications.We evaluate the performance of the developed model using two publicly available retinal image databases,namely RIM-ONE and Drishti-GS.The results demonstrate promising OC segmentation performance across most standard evaluation metrics while achieving analogous results for OD segmentation.We used two retinal fundus image databases named RIM-ONE and Drishti-GS that contained 159 images and 101 retinal images,respectively.For OD segmentation using the RIM-ONE we obtain an f1-score(F1),Jaccard coefficient(JC),and overlapping error(OE)of 0.950,0.9219,and 0.0781,respectively.Similarly,for OC segmentation using the same databases,we achieve scores of 0.8481(F1),0.7428(JC),and 0.2572(OE).Based on these experimental results and the significantly lower number of trainable parameters,we conclude that the developed model is highly suitable for the early diagnosis of glaucoma by accurately estimating the CDR.
基金funded by research projects (NSC97-2221-E-129-003) of the National Science Council
文摘Prandtl-Reuss flow rule and Hill’s yield criterion were adopted and combined with the concept of finite deformation theory, updated Lagrangian formulation, and a three-dimensional finite element analytical model was established by application of quadrilateral four-node degenerated shell elements coupling into a rigid matrix to deal with the sheet metal forming problems. The fractured thickness of a specimen obtained from a simple tension test was used to be the fracture criterion for the numerical analysis to explore the relationship between punch load and stroke, the thickness distribution, the deformation history and the forming limit of work-piece in the elliptical cup drawing process. The numerical analysis and experiment results show that the punch load increases with the increase of punch stroke, and when the load reaches its maximum, the blank continues to deform with the increase of the punch stroke, resulting in a reduced load until the extension is completed. The minimum thickness of the work-piece concentrates in the contact region of the work-piece and long axis of the punch due to the smaller radius of the curvature of the long axis than the short axis. So the blanks bore the maximum tensile stress in the long axis. Through the limit drawing ratio defined by perimeter of the elliptical punch, the limit drawing ratio of this elliptical cup drawing is defined to be 2.136.
基金Project supported by the National Natural Science Foundation of China (Nos. 51004013,50936003,51174028,and 50905013)the Research Foundation of Engineering Research Institute of University of Science and Technology Beijing (No. Yj2011-015)the Fundamental Research Funds for the Central Universities (No. T-RF-TP-12-108A)
文摘The unsteady, laminar, incompressible, and two-dimensional flow of a mi- cropolar fluid between two orthogonally moving porous coaxial disks is considered. The extension of von Karman＇s similarity transformations is used to reduce the governing partial differential equations （PDEs） to a set of non-linear coupled ordinary differential equations （ODEs） in the dimensionless form. The analytical solutions are obtained by employing the homotopy analysis method （HAM）. The effects of various physical param- eters such as the expansion ratio and the permeability Reynolds number on the velocity fields are discussed in detail.
文摘Purpose: The main objective was to analyze the relationship between maximum cup depth (MCD), mean defect (MD), central corneal thickness (CCT), age and disc area, in patients with ocular hypertension (OHT) and primary open angle glaucoma (POAG). Methods: Cross-sectional study of patients diagnosed with OHT and POAG. Visual fields were obtained using an Octopus 300 analyzer, TOP strategy. MCD and disc area were obtained using a Heidelberg Retina Tomograph. Results: The study sample comprised 234 eyes of 143 patients, 91 women and 52 men, mean age 63.55 years (SD 10.49). Mean values were: MCD 0.52 mm (SD 0.27), MD 2.78 dB (SD 5.02), CCT 543.5 μm (SD 36.63), IOP 16.73 mmHg (SD 2.93), and disc area 2.01 mm<sup>2</sup> (SD 0.39). A significant correlation was observed between MCD and age in patients under 60 years, between MCD and disc area, and between MD and disc area. Conclusions: Our study showed a correlation between MCD and age which was significant in patients under 60 years of age, between MCD and disc area and between MD and disc area, suggesting that the larger the disc area, the greater the MCD and the MD in patients with OHT and POAG.
