Classification of Benign and Malignant Pulmonary Nodules Using a Regularized Extreme Learning Machine

Abstract

An L1/L2-norm-bound extreme learning machine classification algorithm is proposed to improve the accuracy of distinguishing between benign and malignant pulmonary nodules. In this algorithm, features extracted from the segmented lung nodule using the histogram of oriented gradients method are used as inputs. L1-norm can promote sparsity in the weights of the output layer, and L2-norm can smooth output weights. The combination of the L1 norm and L2 norm can simplify the complexity of the network and prevent overfitting to improve classification accuracy. For each newly tested lung nodule, the algorithm outputs a class label of either benign or malignant. The accuracy, sensitivity, and specificity reached 94.12%, 93%, and 95% respectively over the lung image database consortium and image database resource initiative dataset. Compared with other algorithms, the average values of the three metrics increased by 6.5%, 7.94%, and 4.32%, respectively. An accuracy score of 95.83% can be achieved over a set of 120 urinary sediment images. Therefore, this algorithm has a good classification effect of pulmonary nodules.