Background and objectives
Pulmonary obstruction diseases produce adventitious sounds in the breathing cycle. With the increased impact of lung diseases, it has become essential for the medical professional to leverage artificial intelligence for faster and more accurate lung auscultation. Initial biomedical signal processing techniques focused on features based on signal amplitude, so accuracy detection depends upon the signal amplitude. The adventitious sounds heard in the respiratory cycle have non-linear characteristics. The present research targets to propose features based on the non-linearity of the adventitious sounds. Also, in this research, SVM-LSTM with the Bayesian optimization model is applied for the first time to test features of adventitious sounds.
Methods
The characteristics of adventitious sounds contain non-linearities. Targeting the same, the research proposes two feature sets based on wavelet bi-spectrum and bi-phase (eight each). SVM-LSTM analyzes these features with the Bayesian optimization algorithm model. The research employs the RALE
database, which is the most comprehensive public database of lung sounds.
Results
The results are presented in a matrix of 3×10 with parameters as MSE, PSNR, R-value, RMSE, and NRMSE from the confusion matrix for SVM, SVM-LSTM, and SVM-LSTM with BO for each class, i.e., wheeze, crackle, and normal. The results are evaluated using Matlab
2021b (MathWorks
, Inc.). Results reveal that feature sets achieved an accuracy of 94.086% for SVM, 94.684% for SVM-LSTM, and 95.699% with 95.161% for LSTM Bayesian optimization for WBS and WBP, respectively.
Conclusion
The research supports the hypothesis that adventitious sounds have non-linear properties. New features are more effective in detecting lung sounds. Also, combining the LSTM with Bayesian optimization improved each class’s accuracy and statistical parameters. The above model design achieved accurate AI-aided detection of lung diseases for light weighted edge devices.