Feature Evaluation of Flow Limitation in Obstructive Sleep Apnea Cases

Abstract

Purpose: Obstructive Sleep Apnea(OSA) is an airway obstructed during sleep, due to intermittent respiratory arrest disease. Flow limitation is an important symptom of OSA, but the method of detecting flow limitation was not clear now. Materials: Signal source record of clinical patients with Polysomnography (PSG), Capture identified as RERA respiratory flow different categories 47 cases respiratory flow signal, 10 cases marked normal, 37 cases marked flow limitation. Method: Use 3 methods to Detect. (1)Flattening index (F.I) feature: Accepted standards for the majority of studies, the mean deviation of the inspiratory wave from the reference amplitude, for a middle portion of the wave are calculated. Weight F.I by F.I is based on the weighted improvements. (2)Value Weight: Weighted above average of inspiratory waveform data. (3)Time Weight: Weighted after the middle of inspiratory waveform data. Results: Comparison 4 different detection methods analysis 47 cases of respiratory flow signal. The results of measurement, F.I could correctly distinguish the 41 cases, the error rate is about 12%. Value Weight could correctly distinguish the 42 cases, the error rate is about 10%. Time Weight could correctly distinguish the 41 cases, the error rate is about 12%. Conclusions: Use described above 4 methods detection can be achieved correct rate of 80% or more. The value weight has the lowest error rate, Can clearly distinguishing severe and mild obstructive, is the best detection of 4 methods. The ability of F.I to distinguish mild and severe slightly inferior to Value Weight, but enhanced slightly discernment. The time weight is particularly suitable for distinguishing M shaped or square shaped respiratory patters indicative of partially obstructed airways.