A Multi-level Deep Neural Network to Diagnose Coronavirus Disease with Imbalanced Data

Abstract

One of the main challenges of medical data mining is the classification of imbalanced datasets. Often the data which are used for training classification is of no proper distribution. It occurs when a class has few samples in nature inclining the learner model to the major class. This imbalance is quite obvious in the data X-ray image of coronavirous, due to its newness, so the samples of healthy and pneumonia are more than COVID- 19 ones. Here we proposed a multi-level model that improves diagnosis of the disease using data augmentation in the minor class of coronavirous cases. The model contains a deep feature extractor, a novel algorithem to find the scatter topolgy of the minor class, a mechanism to selectively generate synthetic samples and finally clasify input data. Coronavirous images are fed to a deep neural networks as a feature estractor. Then, finding scatter topology of the minor class, synthetic samples are generated in the feature space and evaluated by some expertes so that the synthetic samples resemble real ones mostly. Finally, the pool of synthetic and real samples of each classes are transferred to a discriminator network after the dataset is balanced. Results indicate that the production of samples by the framework not only improves classification performance but also has a more desirable performance than other data augmentation methods.