- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Deep structure tensor graph search framework for automated extraction and characterization of retinal layers and fluid pathology in retinal SD-OCT scans
摘要： Maculopathy is a group of retinal disorders that affect macula and cause severe visual impairment if not treated in time. Many computer-aided diagnostic methods have been proposed over the past that automatically detect macular diseases. However, to our best knowledge, no literature is available that provides an end-to-end solution for analyzing healthy and diseased macular pathology. This paper proposes a vendor-independent deep convolutional neural network and structure tensor graph search-based segmentation framework (CNN-STGS) for the extraction and characterization of retinal layers and fluid pathology, along with 3-D retinal profiling. CNN-STGS works by first extracting nine layers from an optical coherence tomography (OCT) scan. Afterward, the extracted layers, combined with a deep CNN model, are used to automatically segment cyst and serous pathology, followed by the autonomous 3-D retinal profiling. CNN-STGS has been validated on publicly available Duke datasets (containing a cumulative of 42,281 scans from 439 subjects) and Armed Forces Institute of Ophthalmology dataset (containing 4,260 OCT scans of 51 subjects), which are acquired through different OCT machinery. The performance of the CNN-STGS framework is validated through the marked annotations, and it significantly outperforms the existing solutions in various metrics. The proposed CNN-STGS framework achieved a mean Dice coefficient of 0.906 for segmenting retinal fluids, along with an accuracy of 98.75% for characterizing cyst and serous fluid from diseased retinal OCT scans.
关键词： convolutional neural network (CNN),Optical coherence tomography (OCT),maculopathy,ophthalmology,graph search
更新于2025-09-23 15:23:52
-
[IEEE 2018 IEEE 21st International Multi-Topic Conference (INMIC) - Karachi, Pakistan (2018.11.1-2018.11.2)] 2018 IEEE 21st International Multi-Topic Conference (INMIC) - Textural and Intensity Feature Based Retinal Vessels Classification for the Identification of Hypertensive Retinopathy
摘要： Hypertensive retinopathy is a retinal disease which results as a consequence of high blood pressure. Its early detection is necessary in reducing the likelihood of permanent visual damage. The percentage of people suffering from Hypertension is high, so it is required to develop a system which automatically detects the presence of this disease. High blood pressure damages retinal vessels and due to which arteries width is reduced. This damage can be analyzed by extracting the blood vessels, classifying the segmented vessels into veins and arteries and their Arteriovenous Ratio, which is an important measure to establish whether a person is suffering from Hypertensive Retinopathy or not. This research presents a technique for automatic classification of blood vessels of retina using different classifiers and the performance of each classifier is compared on same feature set. A novel combination of features is used for classification of vessels, which is an essential step for calculation of Arteriovenous Ratio and subsequently the detection of Hypertensive Retinopathy. MATLAB has been used for this research. The results that are achieved using the proposed feature set show’s 89% accuracy.
关键词： Accuracy (ACC),Arteriovenous Ratio (AVR),Support Vector Machine (SVM),Armed Forces Institute of Ophthalmology (AFIO),Hypertensive Retinopathy (HR)
更新于2025-09-23 15:22:29
-
A Quantum Field Approach for Advancing Optical Coherence Tomography Part I: First Order Correlations, Single Photon Interference, and Quantum Noise
摘要： Optical coherence tomography has become an important imaging technology in cardiology and ophthalmology, with other applications under investigations. Major advances in optical coherence tomography (OCT) imaging are likely to occur through a quantum field approach to the technology. In this paper, which is the first part in a series on the topic, the quantum basis of OCT first order correlations is expressed in terms of full field quantization. Specifically first order correlations are treated as the linear sum of single photon interferences along indistinguishable paths. Photons and the electromagnetic (EM) field are described in terms of quantum harmonic oscillators. While the author feels the study of quantum second order correlations will lead to greater paradigm shifts in the field, addressed in part II, advances from the study of quantum first order correlations are given. In particular, ranging errors are discussed (with remedies) from vacuum fluctuations through the detector port, photon counting errors, and position probability amplitude uncertainty. In addition, the principles of quantum field theory and first order correlations are needed for studying second order correlations in part II.
关键词： Plaque,Quantum mechanics,Interferometry,Ophthalmology,Noise,Vacuum,Cardiology,Arthritis,Optical coherence tomography
更新于2025-09-23 15:22:29
-
New Parametric Imaging Method with Fluorescein Angiograms for Detecting Areas of Capillary Nonperfusion
摘要： Fluorescein angiography (FAG) is currently the most useful diagnostic modality for examining retinal circulation, and it is frequently used for the evaluation of patients with diabetic retinopathy, occlusive diseases, such as retinal venous and arterial occlusions, and wet macular degeneration. This paper presents a method for objectively evaluating retinal circulation by quantifying circulation-related parameters. Methods: This method allows the semiautomatic preprocessing and registering of FAG images. The arterial input function is estimated from the registered set of FAG images using gamma-variate fitting. Then, the parameters can be computed by deconvolution on the basis of truncated singular value decomposition, and they can finally be presented as parametric color images in a combination of three colors, red, green, and blue. Results: After the estimation of arterial input function, the parameters of relative blood flow and mean transit time were computed using deconvolution analysis based on truncated singular value decomposition. Conclusions: The parametric color image is helpful to interpret the status of retinal blood circulation and provides quantitative data on retina ischemia without interobserver variability. This system easily provides the status of retinal blood circulation both qualitatively and quantitatively. It also helps to standardize FAG interpretation and may contribute to network-based telemedicine systems in the future.
关键词： Fluorescein Angiography,Ophthalmology,Computer-Assisted Diagnosis,Eye Disease,Biomedical Engineering
更新于2025-09-23 15:22:29
-
The Additional Diagnostic Value of Optical Coherence Tomography (OCT) and Its Application Procedure in A Wide Variety of Avian Species
摘要： Objective: The current study introduced OCT as a novel tool in clinical veterinary ophthalmology in a much wider variety of free-living avian species than hitherto studied. Methods: OCT was tested and performed in 39 free-living birds (21 species of 12 families) and compared to direct ophthalmoscopy. Birds were examined with combinations of different restraints (manual restraint or fixation on a holding device) and different anaesthesia regimes (none, sedation, general anaesthesia). Inter- and intra-species specific variations of the general procedure, the restraint methods and the clinical findings were evaluated. Results: OCT was possible in all examined avian species (from 40 g up to 7720 g) and superseded direct ophthalmoscopy in quality and quantity of ophthalmological findings. All restraint methods enabled OCT examination, however combination of general anaesthesia and a holding device provided the most rapid and subjectively the least stressful examination technique. Stability, stress reduction, head angle and distance from the OCT device were important factors influencing volume scanning quality. Sixteen, out of 39 birds, presented ocular abnormalities detected by OCT (compared to only five birds when using direct ophthalmoscopy). OCT with included fundus images offered an objective assessment of retinal changes. Retinal abnormalities included changes of fundus pigmentation, drusenoid changes and severe retinal and choroidal degenerations. Species-specific variations of retinal layer dimensions and of foveal structures were evident. Conclusion: OCT is a promising, non-invasive method, which significantly compliments standard techniques. OCT is applicable to a wide variety of avian species; it provides high quality cross-sectional images of the retina, enabling accurate and improved diagnosis and prognosis of therapies. An assessment of the visual capabilities of traumatised birds is a major factor for their rehabilitation and survival in the wild. Finally, this method is an excellent tool in interdisciplinary retinal research, providing novel insights into the diversity of very specialized structural adaptations of avian retina.
关键词： Direct ophthalmoscopy,Raptor,Retina,Optical coherence tomography,Avian ophthalmology
更新于2025-09-23 15:21:21
-
Identification of Gravesa?? ophthalmology by laser-induced breakdown spectroscopy combined with machine learning method
摘要： Diagnosis of the Graves’ ophthalmology remains a significant challenge. We identified between Graves’ ophthalmology tissues and healthy controls by using laser-induced breakdown spectroscopy (LIBS) combined with machine learning method. In this work, the paraffin-embedded samples of the Graves’ ophthalmology were prepared for LIBS spectra acquisition. The metallic elements (Na, K, Al, Ca), non-metallic element (O) and molecular bands ((C-N), (C-O)) were selected for diagnosing Graves’ ophthalmology. The selected spectral lines were inputted into the supervised classification methods including linear discriminant analysis (LDA), support vector machine (SVM), k-nearest neighbor (kNN), and generalized regression neural network (GRNN), respectively. The results showed that the predicted accuracy rates of LDA, SVM, kNN, GRNN were 76.33%, 96.28%, 96.56%, and 96.33%, respectively. The sensitivity of four models were 75.89%, 93.78%, 96.78%, and 96.67%, respectively. The specificity of four models were 76.78%, 98.78%, 96.33%, and 96.00%, respectively. This demonstrated that LIBS assisted with a nonlinear model can be used to identify Graves’ ophthalmopathy with a higher rate of accuracy. The kNN had the best performance by comparing the three nonlinear models. Therefore, LIBS combined with machine learning method can be an effective way to discriminate Graves’ ophthalmology.
关键词： support vector machine (SVM),linear discriminant analysis (LDA),Graves’ ophthalmology,laser-induced breakdown spectroscopy (LIBS),k-nearest neighbor (kNN),generalized regression neural network (GRNN)
更新于2025-09-23 15:21:01
-
Safety and Efficacy of YAG Laser Vitreolysis for the Treatment of Vitreous Floaters: An Overview
摘要： Emerging evidence has suggested that the entoptic phenomena associated with vitreous opacities (i.e. vitreous floaters) are more bothersome than previously believed. In addition, the prevalence of vitreous floaters is likely increasing due to the evolving global pandemic of myopia. The use of YAG laser vitreolysis for the treatment of annoying vitreous floaters has attracted significant attention in recent years as the technique offers a number of potential advantages. Unfortunately, the currently available evidence that is needed to guide clinical practice is both very limited and contradictory. As a consequence, the technique remains highly controversial. A review of the existing literature sheds light on patient- and treatment-related factors that may significantly affect both the effectiveness and the safety of the procedure. The current article discusses important aspects of key publications on the topic, offers suggestions for clinical practice, and highlights unmet needs that should be addressed by future research.
关键词： Vitreous floaters,Weiss ring,PVD,Floaters,Posterior vitreous detachment,Vitreolysis,YAG,Ophthalmology,Myodesopsia
更新于2025-09-23 15:19:57
-
Antimicrobial biomaterials and their potential application in ophthalmology
摘要： Infections associated with the use of intraocular, periocular, or orbital implants are associated with an increase in both morbidity and in the costs of ophthalmological surgery. This is due to an increased number of visits and the need for additional treatments, at a time when some conventional therapies are losing their efficacy, or even hospitalization. To avoid such consequences, the first step should be to prevent the biomaterials that form implants from being colonized by various microorganisms, either intraoperatively or postoperatively. To this end, several lines of research have emerged that aim at equipping implants with antimicrobial properties, some of which are described in this review.
关键词： Ophthalmology,Implant-associated infections,Antimicrobial biomaterials
更新于2025-09-19 17:15:36
-
Ergonomic aspects in the design of instrumentation for ophthalmic microsurgery; Aspekte der Ergonomie bei der Gestaltung von Instrumenten der ophthalmologischen Mikrochirurgie;
摘要： The following report introduces two projects, dealing about ergonomics in ophthalmic microsurgery. The first project is devoted to the development of a method, by means of which the design of microsurgical instrumentation is evaluated quantitatively. Developed method particularly considers conditions of instrument use as found in microsurgical practice. In a first attempt, the method was validated using laypersons. In the second project, various measures are introduced aiming to improve the posture of the surgeon during the microsurgery. One of the measures consists in using a large 3D-monitor to present the microscopic image to the surgeon instead of viewing the image through the oculars of a traditional microscope. The measure therefore enables a more relaxed posture of the surgeon. In addition, a chair was developed, considering to support the surgeon's posture when operating using the 3D-monitor or the traditional microscope while performing the microsurgery. Practical relevance. The method suggested in the first project closes a gap in product design as it provides developers with a quantitative, objective and ecologic valid methods for evaluating designs of microsurgical instrumentation. The measures presented in the second project will contribute to reduce postural complaints of the surgeon caused by microsurgical interventions.
关键词： ophthalmology,posture,product ergonomics,3D-visualization,microsurgery,fine motor control
更新于2025-09-19 17:15:36
-
Experiencia de atención en red entre Hospital del Salvador y tres unidades de Atención Primaria Oftalmológica: Un modelo de salud pública para mejorar la atención oftalmológica
摘要： Background: Primary care units of ophtalmology (UAPO) were incorporated in 2003 into the healthcare system of the Ministry of Health, in response to the high demand for hospital care. Three of these primary care units were incorporated to provide a network care with the ophthalmology service of a tertiary care hospital. Aim: To report the public health impact of networking. Material and Methods: A descriptive-prospective study was carried out analyzing all the healthcare attentions carried out between June and August 2016. An epidemiological characterization of the sample was made. We recorded: clinical diagnoses, decisions, resolution of the clinical problem at the primary care or referral to the hospital. Results: A total of 2,096 ophthalmologic attentions were carried out in the three UAPOs during the study period. The main diseases attended were disorders of refraction, cataracts, glaucoma and diabetic retinopathy. The resolution index was 84% of attentions. Only 16% of attentions required referral and consisted mainly of cataracts (covered by a special health care system), diabetic retinopathy, capsulotomies, iridotomies, uveitis, pterygium and lacrimal duct obstruction. Conclusions: This model of care allowed an efficient management of the high demand for hospital referral. This is expressed in the high-resolution index and low derivation, resulting in a decrease in waiting lists at the tertiary level. This system should be implemented by other tertiary centers of our country.
关键词： Ophthalmology,Primary Health Care,Tertiary Healthcare
更新于2025-09-19 17:15:36