Tracheal sound parameters of respiratory cycle phases show differences between flow-limited and normal breathing during sleep.
The objective of the present work was to develop new computational parameters to examine the characteristics of respiratory cycle phases from the tracheal breathing sound signal during sleep. Tracheal sound data from 14 patients (10 males and 4 females) were examined. From each patient, a 10 min long section of normal and a 10 min section of flow-limited breathing during sleep were analysed. The computationally determined proportional durations of the respiratory phases were first investigated. Moreover, the phase durations and breathing sound amplitude levels were used to calculate the area under the breathing sound envelope signal during inspiration and expiration phases. An inspiratory sound index was then developed to provide the percentage of this type of area during the inspiratory phase with respect to the combined area of inspiratory and expiratory phases. The proportional duration of the inspiratory phase showed statistically significantly higher values during flow-limited breathing than during normal breathing and inspiratory pause displayed an opposite difference. The inspiratory sound index showed statistically significantly higher values during flow-limited breathing than during normal breathing. The presented novel computational parameters could contribute to the examination of sleep-disordered breathing or as a screening tool.
Department of Clinical Neurophysiology, Medical Imaging Centre, Pirkanmaa Hospital District, Tampere, Finland. antti.kulkas@pshp.fi
A
A
Kulkas
E
E
Huupponen
J
J
Virkkala
A
A
Saastamoinen
E
E
Rauhala
M
M
Tenhunen
S-L
SL
Himanen
D000293:Adolescent; D000328:Adult; D000465:Algorithms; D019540:Area Under Curve; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012119:Respiration; D012120:Respiration Disorders / Q000503:physiopathology*; D012135:Respiratory Sounds; D012815:Signal Processing, Computer-Assisted; D012890:Sleep / Q000502:physiology*; D013018:Sound Spectrography; D013997:Time Factors; D014132:Trachea / Q000502:physiology*; D055815:Young Adult