A novel ensemble learning framework based on a genetic algorithm for the classification of pneumonia

Pneumonia is a disease that can be detected by the opacity changes in chest X-rays and can lead to fatal consequences. Medical image analysis has several challenges, such as limited labeled datasets, imbalanced class distribution, image noise, and overfitting, so individual Convolutional Neural Networks (CNNs) are insufficient to detect pneumonia accurately. Although ensemble CNN models have been used in previous studies, the literature lacks guidance on identifying the optimal CNN models and weight ratio to combine them. In this study, we propose a novel ensemble CNN framework to accurately detect pneumonia, with optimum weights set by a Genetic Algorithm (GA). Firstly, a noise outside the lung was removed, and the model performance was enhanced by performing lung segmentation on Chest X-ray. The performances of several CNN models were analyzed by hyperparameter optimization. The framework combines the three models that give the best accuracy and the two models that provide the lowest false-negative value with the ensemble method in the ratio of the most appropriate weights. The proposed framework provided the best performance on the public test dataset with an accuracy of 97.23% and an F1-score of 97.45% compared to state-of-the-art methods. The study's main contributions are determining suitable models and their optimal weights of the ensemble method based on the GA. The proposed framework enables a rapid and effective diagnostic process, less costly healthcare services, and more efficient use of resources. The demo-link is https://www.youtube.com/watch?v=KZ50K3HL70U.