133 research outputs found
Blended Multi-Modal Deep ConvNet Features for Diabetic Retinopathy Severity Prediction
Diabetic Retinopathy (DR) is one of the major causes of visual impairment and
blindness across the world. It is usually found in patients who suffer from
diabetes for a long period. The major focus of this work is to derive optimal
representation of retinal images that further helps to improve the performance
of DR recognition models. To extract optimal representation, features extracted
from multiple pre-trained ConvNet models are blended using proposed multi-modal
fusion module. These final representations are used to train a Deep Neural
Network (DNN) used for DR identification and severity level prediction. As each
ConvNet extracts different features, fusing them using 1D pooling and cross
pooling leads to better representation than using features extracted from a
single ConvNet. Experimental studies on benchmark Kaggle APTOS 2019 contest
dataset reveals that the model trained on proposed blended feature
representations is superior to the existing methods. In addition, we notice
that cross average pooling based fusion of features from Xception and VGG16 is
the most appropriate for DR recognition. With the proposed model, we achieve an
accuracy of 97.41%, and a kappa statistic of 94.82 for DR identification and an
accuracy of 81.7% and a kappa statistic of 71.1% for severity level prediction.
Another interesting observation is that DNN with dropout at input layer
converges more quickly when trained using blended features, compared to the
same model trained using uni-modal deep features.Comment: 18 pages, 8 figures, published in Electronics MDPI journa
Deep Learning Based Models for Detection of Diabetic Retinopathy
Diabetic retinopathy (DR) is an important disease that occurs because of damage to the retinal blood vessels in the human eye due to diabetes and causes blindness. If diagnosed correctly, the treatments to be applied increase the possibility of preventing vision loss or blindness. This study aims to present an evaluation of deep learning methods to detect diabetic retinopathy from retinal images. In this direction, the VGG16 model was considered, and two different versions of this model were obtained by making improvements. Besides, a model has been proposed, the first layers are dense, the next layers have decreasing convolution, and have fewer layers. According to the results, the VGG16 model, which reached 75.48% accuracy, reached 76.57% accuracy due to the dropout layer added to the classification layers, and 77.11% accuracy due to the dropout layer added to all blocks. The highest accuracy was obtained in the proposed model with 81.74%
Optic-Net: A Novel Convolutional Neural Network for Diagnosis of Retinal Diseases from Optical Tomography Images
Diagnosing different retinal diseases from Spectral Domain Optical Coherence
Tomography (SD-OCT) images is a challenging task. Different automated
approaches such as image processing, machine learning and deep learning
algorithms have been used for early detection and diagnosis of retinal
diseases. Unfortunately, these are prone to error and computational
inefficiency, which requires further intervention from human experts. In this
paper, we propose a novel convolution neural network architecture to
successfully distinguish between different degeneration of retinal layers and
their underlying causes. The proposed novel architecture outperforms other
classification models while addressing the issue of gradient explosion. Our
approach reaches near perfect accuracy of 99.8% and 100% for two separately
available Retinal SD-OCT data-set respectively. Additionally, our architecture
predicts retinal diseases in real time while outperforming human
diagnosticians.Comment: 8 pages. Accepted to 18th IEEE International Conference on Machine
Learning and Applications (ICMLA 2019
Deep Learning Techniques for Medical Image Classification
A thesis submitted in partial fulfillment of the requirements for the degree of Doctor in Information Management, specialization in Information and Decision SystemsIn recent years, artificial intelligence (AI) has been applied in many fields to address complex and critical real-world tasks. Deep learning rises as a subfield of AI, where artificial neural networks (ANN) are used to map complicated functions, which can be challenging even for experienced users. One of the ANN variants is called convolutional neural network (CNN), which has shown great potential in image processing by providing state-of-the-art results for many significant image processing challenges. The medical field can significantly benefit from AI usage, especially in the medical image classification domain. In this doctoral dissertation, we applied different AI techniques to analyze medical images and to give the physicians a second opinion or reduce the time and effort needed for the image classification. Initially, we reviewed several studies that were published to discuss the transfer learning of CNNs. Afterward, we studied different hyperparameters that need to be optimized for CNNs to be trained accurately. Lastly, we proposed a novel CNN architecture to help in the classification of histopathology images
Applying supervised contrastive learning for the detection of diabetic retinopathy and its severity levels from fundus images
Diabetic Retinopathy (DR) is a major complication in human eyes among the diabetic patients. Early detection of the DR can save many patients from permanent blindness. Various artificial intelligent based systems have been proposed and they outperform human analysis in accurate detection of the DR. In most of the traditional deep learning models, the cross-entropy is used as a common loss function in a single stage end-to-end training method. However, it has been recently identified that this loss function has some limitations such as poor margin leading to false results, sensitive to noisy data and hyperparameter variations. To overcome these issues, supervised contrastive learning (SCL) has been introduced. In this study, SCL method, a two-stage training method with supervised contrastive loss function was proposed for the first time to the best of authors' knowledge to identify the DR and its severity stages from fundus images (FIs) using “APTOS 2019 Blindness Detection” dataset. “Messidor-2” dataset was also used to conduct experiments for further validating the model's performance. Contrast Limited Adaptive Histogram Equalization (CLAHE) was applied for enhancing the image quality and the pre-trained Xception CNN model was deployed as the encoder with transfer learning. To interpret the SCL of the model, t-SNE method was used to visualize the embedding space (unit hyper sphere) composed of 128 D space into a 2 D space. The proposed model achieved a test accuracy of 98.36%, and AUC score of 98.50% to identify the DR (Binary classification) and a test accuracy of 84.364%, and AUC score of 93.819% for five stages grading with the APTOS 2019 dataset. Other evaluation metrics (precision, recall, F1-score) were also determined with APTOS 2019 as well as with Messidor-2 for analyzing the performance of the proposed model. It was also concluded that the proposed method achieved better performance in detecting the DR compared to the conventional CNN without SCL and other state-of-the-art methods
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