Improving Lung Sound Classification through Multi-Transform Features and Enhanced LSTM Modeling

Timely and correct perception of the lung sounds is necessitated in order to identify any respiratory disorders early enough as well as trimming down the subjective nature in the exercise of the conventional auscultation. In the current paper, a classification structure based on a hybrid loss incorporates a mixture of multi-transform spectral features and an Enhanced Long Short- Memory with Train (ELSTM) network. The test was run on the ICBHI 2017 database of 920 records of 126 subjects including healthy and pathological cases. A Savitzky Golay filter has been used to eliminate the noises to improve the quality of the signal. The Short-Time Fourier transform (STFT) features, Stockwell transform features, spectral roll-off features were combined and fed into a three layer ELSTM dropout network (128-64-32 units). A combination of the Categorical Cross-Entropy and Focal Loss was adopted in training so as to handle the issue of the class imbalance. The sensitivity of the system is 93.7 and the specificity of the system is 94.2 which is higher than CNN, GRU and Bi-LSTM baselines which attained 96 percent accuracy and 93.7 percent sensitivity.