title: Detection of bronchial breathing caused by pneumonia.
abstract: The classic auscultation with stethoscope is the established clinical method for the detection of lung diseases. The interpretation of the sounds depends on the experience of the investigating physician. Therefore, a new computer-based method has been developed to classify breath sounds from digital lung sound recordings. Lung sounds of 11 patients with one-sided pneumonia and bronchial breathing were recorded on both the pneumonia side and on contralateral healthy side simultaneously using two microphones. The spectral power for the 300-600 Hz frequency band was computed for four respiratory cycles and normalized. For each breath, the ratio R between the time-segments (duration = 0.1 s) with the highest inspiratory and highest expiratory flow was calculated and averaged. We found significant differences in R between the pneumonia side (R = 1.4 +/- 1.3) and the healthy side (R = 0.5 +/- 0.5; p = 0.003 Wilcoxon-test) of lung. In 218 healthy volunteers we found R = 0.3 +/- 0.2 as a reference-value. The differences of ratio R (delta R) between the pneumonia side and the healthy side (delta R = 1.0 +/- 0.9) were significantly higher compared to follow-up studies after recovery (delta R = 0.0 +/- 0.1, p = 0.005 Wilcoxon-test). The computer based detection of bronchial breathing can be considered useful as part of a quantitative monitoring of patients at risk to develop pneumonia.
authors.affiliation: Dept. of Respir. and Crit. Care Med., Philipps-University of Marburg. grossv@mailer.uni-marburg.de
authors.forename: V
authors.initials: V
authors.lastname: Gross
authors.forename: P
authors.initials: P
authors.lastname: Fachinger
authors.forename: Th
authors.initials: T
authors.lastname: Penzel
authors.forename: U
authors.initials: U
authors.lastname: Koehler
authors.forename: P
authors.initials: P
authors.lastname: von Wichert
authors.forename: C
authors.initials: C
authors.lastname: Vogelmeier
mesh_terms: D001314:Auscultation; D001980:Bronchi / Q000503:physiopathology; D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D005500:Follow-Up Studies; D005583:Fourier Analysis; D006801:Humans; D011014:Pneumonia / Q000175:diagnosis* / Q000503:physiopathology; D012016:Reference Values; D012135:Respiratory Sounds / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*