Analysis of inspiratory flow shapes in patients with partial upper-airway obstruction during sleep

Chest. 2001 Jan;119(1):37-44. doi: 10.1378/chest.119.1.37.


Study objective: To study the spectrum of inspiratory flow signal shapes in patients with partial upper airway obstruction during sleep.

Design: We identified seven different inspiratory flow shapes and determined their frequencies in two groups of patients (10 postmenopausal women and 19 men after surgical treatment for sleep apnea) and in 9 control subjects.

Setting: Sleep research unit, Department of Physiology, University of Turku, Finland.

Measurements and results: Nasal flow was recorded with nasal prongs. The shape analyses were performed with an automated attribute grammar recognizer. The inspiratory flow-shape distributions differed significantly between patients and control subjects. The flow shapes were also different between postmenopausal women and men after uvulopalatopharyngoplasty.

Conclusions: The differences in the inspiratory flow-shape distributions between the control subjects and the two patient groups suggest that the upper airways behave differently in the three study groups. Automated inspiratory flow-shape analysis seems to be a promising tool to distinguish patient groups with different upper airway function to be treated with different treatment alternatives. The physiologic correlates of each flow-shape class remain to be elucidated.

MeSH terms

  • Adult
  • Female
  • Humans
  • Inspiratory Capacity / physiology*
  • Male
  • Middle Aged
  • Palate / physiopathology
  • Palate / surgery
  • Pharynx / physiopathology
  • Pharynx / surgery
  • Polysomnography
  • Postmenopause / physiology
  • Pulmonary Ventilation / physiology*
  • Reference Values
  • Signal Processing, Computer-Assisted
  • Sleep Apnea, Obstructive / diagnosis*
  • Sleep Apnea, Obstructive / physiopathology
  • Sleep Apnea, Obstructive / surgery
  • Uvula / physiopathology
  • Uvula / surgery