Characterization and classification of asthmatic wheeze sounds according to severity level using spectral integrated features. (January 2019)

• Record Type: Journal Article
• Authors: Nabi, Fizza Ghulam; Sundaraj, Kenneth; Lam, Chee Kiang; Palaniappan, Rajkumar
• Is Part Of: Computers in biology and medicine. Volume 104(2019)
• Page Start: 52
• Page End: 61
• Publication Date: 2019-01
• Subjects: Asthma -- Breath sounds -- Wheeze classification -- Airway obstruction -- Severity level; Medicine -- Data processing -- Periodicals; Biology -- Data processing -- Periodicals; 610.285
• DOI: 10.1016/j.compbiomed.2018.10.035
• Languages: English
• ISSNs: 0010-4825

Abstract

Abstract: Objective: This study aimed to investigate and classify wheeze sounds of asthmatic patients according to their severity level (mild, moderate and severe) using spectral integrated (SI) features. Method: Segmented and validated wheeze sounds were obtained from auscultation recordings of the trachea and lower lung base of 55 asthmatic patients during tidal breathing manoeuvres. The segments were multi-labelled into 9 groups based on the auscultation location and/or breath phases. Bandwidths were selected based on the physiology, and a corresponding SI feature was computed for each segment. Univariate and multivariate statistical analyses were then performed to investigate the discriminatory behaviour of the features with respect to the severity levels in the various groups. The asthmatic severity levels in the groups were then classified using the ensemble (ENS), support vector machine (SVM) and k-nearest neighbour (KNN) methods. Results and conclusion: All statistical comparisons exhibited a significant difference (p < 0.05) among the severity levels with few exceptions. In the classification experiments, the ensemble classifier exhibited better performance in terms of sensitivity, specificity and positive predictive value (PPV). The trachea inspiratory group showed the highest classification performance compared with all the other groups. Overall, the best PPV for the mild, moderate and severe samples were 95% (ENS), 88% (ENS) and 90% (SVM), respectively. With respect to location, the tracheal related wheeze sounds were most sensitive and specific predictors of asthma severity levels. In addition, the classification performances of the inspiratory and expiratory related groups were comparable, suggesting that the samples from these locations are equally informative. Highlights: Spectral integrated features of wheeze sounds can be employed to identify severity levels of asthmatic patients using tidal breathing manoeuvres. Tracheal wheeze sounds are more predictive compared to lower lung base sounds for asthma severity levels identification. Both breath phases have been found to be equally informative for the investigation of asthma severity levels.