Automatic Signal Quality Index Determination of Radar-Recorded Heart Sound Signals Using Ensemble Classification.

Journal
IEEE transactions on biomedical engineering  
Volume
67
Issue
3
Start Page
773
End Page
785
Article Number
8731709
Citation
IEEE Transactions on Biomedical Engineering 3 (67): 8731709 (2020)
Publisher DOI
10.1109/TBME.2019.2921071
Scopus ID
2-s2.0-85078963746
Objective: Radar technology promises to be a touchless and thereby burden-free method for continuous heart sound monitoring, which can be used to detect cardiovascular diseases. However, the first and most crucial step is to differentiate between high-and low-quality segments in a recording to assess their suitability for a subsequent automated analysis. This paper gives a comprehensive study on this task and first addresses the specific characteristics of radar-recorded heart sound signals. Methods: To gather heart sound signals recorded from radar, a bistatic radar system was built and installed at the university hospital. Under medical supervision, heart sound data were recorded from 30 healthy test subjects. The signals were segmented and labeled as high-or low-quality by a medical expert. Different state-of-the-art pattern classification algorithms were evaluated for the task of automated signal quality determination and the most promising one was optimized and evaluated using leave-one-subject-out cross validation. Results: The proposed classifier is able to achieve an accuracy of up to 96.36% and demonstrates a superior classification performance compared with the state-of-the-art classifier with a maximum accuracy of 76.00%. Conclusion: This paper introduces an ensemble classifier that is able to perform automated signal quality determination of radar-recorded heart sound signals with a high accuracy. Significance: Besides achieving a higher performance compared with state-of-the-art classifiers, this study is the first one to deal with the quality determination of heart sounds that are recorded by radar systems. The proposed method enables contactless and continuous heart sound monitoring for the detection of cardiovascular diseases.
Subjects
Biomedical engineering
biomedical informatics
biomedical signal processing
heart sounds
medical radar
pattern recognition
phonocardiography