LGD_Net: Capsule network with extreme learning machine for classification of lung diseases using CT scans

Lung diseases (LGDs) are related to an extensive range of lung disorders, including pneumonia (PNEUM), lung cancer (LC), tuberculosis (TB), and COVID-19 etc. The diagnosis of LGDs is performed by using different medical imaging such as X-rays, CT scans, and MRI. However, LGDs contain similar symptoms such as fever, cough, and sore throat, making it challenging for radiologists to classify these LGDs. If LGDs are not diagnosed at their initial phase, they may produce severe complications or even death. An automated classifier is required for the classification of LGDs. Thus, this study aims to propose a novel model named lung diseases classification network (LGD_Net) based on the combination of a capsule network (CapsNet) with the extreme learning machine (ELM) for the classification of five different LGDs such as PNEUM, LC, TB, COVID-19 omicron (COO), and normal (NOR) using CT scans. The LGD_Net model is trained and tested on the five publicly available benchmark datasets. The datasets contain an imbalanced distribution of images; therefore, a borderline SMOTE (BL_SMT) approach is applied to handle this problem. Additionally, the affine transformation methods are used to enhance LGD datasets. The performance of the LGD_Net is compared with four CNN-based baseline models such as Vgg-19 (D1), ResNet-101 (D2), Inception-v3 (D3), and DenseNet-169 (D4). The LGD_Net model achieves an accuracy of 99.71% in classifying LGDs using CT scans. While the other models such as D1, D2, D3, and D4 attains an accuracy of 91.21%, 94.39%, 93.96%, and 93.82%, respectively. The findings demonstrate that the LGD_Net model works significantly as compared to D1, D2, D3, and D4 as well as state-of-the-art (SOTA). Thus, this study concludes that the LGD_Net model provides significant assistance to radiologists in classifying several LGDs.