Title
Automatic Classification Of Adventitious Respiratory Sounds: A (Un)Solved Problem?
Abstract
(1) Background: Patients with respiratory conditions typically exhibit adventitious respiratory sounds (ARS), such as wheezes and crackles. ARS events have variable duration. In this work we studied the influence of event duration on automatic ARS classification, namely, how the creation of the Other class (negative class) affected the classifiers' performance. (2) Methods: We conducted a set of experiments where we varied the durations of the other events on three tasks: crackle vs. wheeze vs. other (3 Class); crackle vs. other (2 Class Crackles); and wheeze vs. other (2 Class Wheezes). Four classifiers (linear discriminant analysis, support vector machines, boosted trees, and convolutional neural networks) were evaluated on those tasks using an open access respiratory sound database. (3) Results: While on the 3 Class task with fixed durations, the best classifier achieved an accuracy of 96.9%, the same classifier reached an accuracy of 81.8% on the more realistic 3 Class task with variable durations. (4) Conclusion: These results demonstrate the importance of experimental design on the assessment of the performance of automatic ARS classification algorithms. Furthermore, they also indicate, unlike what is stated in the literature, that the automatic classification of ARS is not a solved problem, as the algorithms' performance decreases substantially under complex evaluation scenarios.
Year
DOI
Venue
2021
10.3390/s21010057
SENSORS
Keywords
DocType
Volume
adventitious respiratory sounds, experimental design, machine learning
Journal
21
Issue
ISSN
Citations 
1
1424-8220
1
PageRank 
References 
Authors
0.43
0
5
Name
Order
Citations
PageRank
Bruno Rocha131.84
Diogo Pessoa211.79
Alda Marques3285.31
Paulo Carvalho425047.68
Rui Pedro Paiva510717.38