title: Validation of computerized wheeze detection in young infants during the first months of life.
abstract: BACKGROUND
  Several respiratory diseases are associated with specific respiratory sounds. In contrast to auscultation, computerized lung sound analysis is objective and can be performed continuously over an extended period. Moreover, audio recordings can be stored. Computerized lung sounds have rarely been assessed in neonates during the first year of life. This study was designed to determine and validate optimal cut-off values for computerized wheeze detection, based on the assessment by trained clinicians of stored records of lung sounds, in infants aged <1 year.
  
  
  METHODS
  Lung sounds in 120 sleeping infants, of median (interquartile range) postmenstrual age of 51 (44.5-67.5) weeks, were recorded on 144 test occasions by an automatic wheeze detection device (PulmoTrack®). The records were retrospectively evaluated by three trained clinicians blinded to the results. Optimal cut-off values for the automatically determined relative durations of inspiratory and expiratory wheezing were determined by receiver operating curve analysis, and sensitivity and specificity were calculated.
  
  
  RESULTS
  The optimal cut-off values for the automatically detected durations of inspiratory and expiratory wheezing were 2% and 3%, respectively. These cutoffs had a sensitivity and specificity of 85.7% and 80.7%, respectively, for inspiratory wheezing and 84.6% and 82.5%, respectively, for expiratory wheezing. Inter-observer reliability among the experts was moderate, with a Fleiss' Kappa (95% confidence interval) of 0.59 (0.57-0.62) for inspiratory and 0.54 (0.52 - 0.57) for expiratory wheezing.
  
  
  CONCLUSIONS
  Computerized wheeze detection is feasible during the first year of life. This method is more objective and can be more readily standardized than subjective auscultation, providing quantitative and noninvasive information about the extent of wheezing.
authors.forename: Lia C
authors.initials: LC
authors.lastname: Puder
authors.forename: Hendrik S
authors.initials: HS
authors.lastname: Fischer
authors.forename: Silke
authors.initials: S
authors.lastname: Wilitzki
authors.forename: Jakob
authors.initials: J
authors.lastname: Usemann
authors.forename: Simon
authors.initials: S
authors.lastname: Godfrey
authors.affiliation: Department of Neonatology, Charité University Medical Center, Berlin, Germany. gerd.schmalisch@charite.de.
authors.forename: Gerd
authors.initials: G
authors.lastname: Schmalisch
mesh_terms: D003936:Diagnosis, Computer-Assisted / Q000295:instrumentation*; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007223:Infant; D008297:Male; D015588:Observer Variation; D012372:ROC Curve; D012135:Respiratory Sounds; D012189:Retrospective Studies; D012680:Sensitivity and Specificity