798 research outputs found
Zoom-in-Net: Deep Mining Lesions for Diabetic Retinopathy Detection
We propose a convolution neural network based algorithm for simultaneously
diagnosing diabetic retinopathy and highlighting suspicious regions. Our
contributions are two folds: 1) a network termed Zoom-in-Net which mimics the
zoom-in process of a clinician to examine the retinal images. Trained with only
image-level supervisions, Zoomin-Net can generate attention maps which
highlight suspicious regions, and predicts the disease level accurately based
on both the whole image and its high resolution suspicious patches. 2) Only
four bounding boxes generated from the automatically learned attention maps are
enough to cover 80% of the lesions labeled by an experienced ophthalmologist,
which shows good localization ability of the attention maps. By clustering
features at high response locations on the attention maps, we discover
meaningful clusters which contain potential lesions in diabetic retinopathy.
Experiments show that our algorithm outperform the state-of-the-art methods on
two datasets, EyePACS and Messidor.Comment: accepted by MICCAI 201
Automatic Classification of Bright Retinal Lesions via Deep Network Features
The diabetic retinopathy is timely diagonalized through color eye fundus
images by experienced ophthalmologists, in order to recognize potential retinal
features and identify early-blindness cases. In this paper, it is proposed to
extract deep features from the last fully-connected layer of, four different,
pre-trained convolutional neural networks. These features are then feeded into
a non-linear classifier to discriminate three-class diabetic cases, i.e.,
normal, exudates, and drusen. Averaged across 1113 color retinal images
collected from six publicly available annotated datasets, the deep features
approach perform better than the classical bag-of-words approach. The proposed
approaches have an average accuracy between 91.23% and 92.00% with more than
13% improvement over the traditional state of art methods.Comment: Preprint submitted to Journal of Medical Imaging | SPIE (Tue, Jul 28,
2017
A Flexible and Adaptive Framework for Abstention Under Class Imbalance
In practical applications of machine learning, it is often desirable to
identify and abstain on examples where the model's predictions are likely to be
incorrect. Much of the prior work on this topic focused on out-of-distribution
detection or performance metrics such as top-k accuracy. Comparatively little
attention was given to metrics such as area-under-the-curve or Cohen's Kappa,
which are extremely relevant for imbalanced datasets. Abstention strategies
aimed at top-k accuracy can produce poor results on these metrics when applied
to imbalanced datasets, even when all examples are in-distribution. We propose
a framework to address this gap. Our framework leverages the insight that
calibrated probability estimates can be used as a proxy for the true class
labels, thereby allowing us to estimate the change in an arbitrary metric if an
example were abstained on. Using this framework, we derive computationally
efficient metric-specific abstention algorithms for optimizing the sensitivity
at a target specificity level, the area under the ROC, and the weighted Cohen's
Kappa. Because our method relies only on calibrated probability estimates, we
further show that by leveraging recent work on domain adaptation under label
shift, we can generalize to test-set distributions that may have a different
class imbalance compared to the training set distribution. On various
experiments involving medical imaging, natural language processing, computer
vision and genomics, we demonstrate the effectiveness of our approach. Source
code available at https://github.com/blindauth/abstention. Colab notebooks
reproducing results available at
https://github.com/blindauth/abstention_experiments
Neuropathy Classification of Corneal Nerve Images Using Artificial Intelligence
Nerve variations in the human cornea have been associated with alterations in
the neuropathy state of a patient suffering from chronic diseases. For some diseases,
such as diabetes, detection of neuropathy prior to visible symptoms is important,
whereas for others, such as multiple sclerosis, early prediction of disease worsening is
crucial. As current methods fail to provide early diagnosis of neuropathy, in vivo
corneal confocal microscopy enables very early insight into the nerve damage by
illuminating and magnifying the human cornea. This non-invasive method captures a
sequence of images from the corneal sub-basal nerve plexus. Current practices of
manual nerve tracing and classification impede the advancement of medical research in
this domain. Since corneal nerve analysis for neuropathy is in its initial stages, there is
a dire need for process automation.
To address this limitation, we seek to automate the two stages of this process:
nerve segmentation and neuropathy classification of images. For nerve segmentation,
we compare the performance of two existing solutions on multiple datasets to select the
appropriate method and proceed to the classification stage. Consequently, we approach
neuropathy classification of the images through artificial intelligence using Adaptive
Neuro-Fuzzy Inference System, Support Vector Machines, Naïve Bayes and k-nearest
neighbors. We further compare the performance of machine learning classifiers with
deep learning. We ascertained that nerve segmentation using convolutional neural networks provided a significant improvement in sensitivity and false negative rate by
at least 5% over the state-of-the-art software. For classification, ANFIS yielded the best
classification accuracy of 93.7% compared to other classifiers. Furthermore, for this
problem, machine learning approaches performed better in terms of classification
accuracy than deep learning
Automatic Screening and Classification of Diabetic Retinopathy Eye Fundus Image
Diabetic Retinopathy (DR) is a disorder of the retinal vasculature. It develops to some degree in nearly all patients with long-standing diabetes mellitus and can result in blindness. Screening of DR is essential for both early detection and early treatment. This thesis aims to investigate automatic methods for diabetic retinopathy detection and subsequently develop an effective system for the detection and screening of diabetic retinopathy.
The presented diabetic retinopathy research involves three development stages. Firstly, the thesis presents the development of a preliminary classification and screening system for diabetic retinopathy using eye fundus images. The research will then focus on the detection of the earliest signs of diabetic retinopathy, which are the microaneurysms. The detection of microaneurysms at an early stage is vital and is the first step in preventing diabetic retinopathy. Finally, the thesis will present decision support systems for the detection of diabetic retinopathy and maculopathy in eye fundus images. The detection of maculopathy, which are yellow lesions near the macula, is essential as it will eventually cause the loss of vision if the affected macula is not treated in time.
An accurate retinal screening, therefore, is required to assist the retinal screeners to classify the retinal images effectively. Highly efficient and accurate image processing techniques must thus be used in order to produce an effective screening of diabetic retinopathy. In addition to the proposed diabetic retinopathy detection systems, this thesis will present a new dataset, and will highlight the dataset collection, the expert diagnosis process and the advantages of the new dataset, compared to other public eye fundus images datasets available. The new dataset will be useful to researchers and practitioners working in the retinal imaging area and would widely encourage comparative studies in the field of diabetic retinopathy research. It is envisaged that the proposed decision support system for clinical screening would greatly contribute to and assist the management and the detection of diabetic retinopathy. It is also hoped that the developed automatic detection techniques will assist clinicians to diagnose diabetic retinopathy at an early stage
Development of a Low-Cost Eye Screening Tool for Early Detection of Diabetic Retinopathy using Deep Neural Network
It has been said that technology used in the lab does not directly transfer to what is done in healthcare. Research on the use of Artificial Intelligence (AI) in the diagnosis of Diabetic Retinopathy (DR) has seen tremendous growth over the last couple of years but it is also true not much of that knowledge has been transferred into practice to benefit patients in need. One reason is that it’s a new frontier with untested technologies and one that is evolving too fast. Also, the Real Healthcare situation can be very complicated presenting itself with numerous challenges starting with strict regulations to variability in populations. A solution that is implementable needs to address all these concerns including ethics, standards, and any security concerns. It is also important to note that, the current state of AI is specialized to only narrow applications and may not scale when presented with problems of varied nature. A case in point is a patient having DR may be suffering from other ailments such as Glaucoma or cataracts. DR has been a leading cause of blindness for millions of people worldwide, hard to detect when it’s treatable and therefore early eye screening is the solution. In this Capstone project, we seek to integrate Artificial Intelligence with other technologies to deliver a low-cost diagnosis to Diabetic Retinopathy at the same time trying to overcome previous impediments to the implementation of mass eye screening
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