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