Abstract
Oxygen saturation obtained from nocturnal pulse oximetry isa significant evaluation parameter for sleep related breathingdisorders, especially in the diagnosis of the obstructive sleepapnea syndrome (OSA). Today clinical interpretation reliesmainly on the number of desaturation events per hour (oxygen desaturation index, ODI). In this study various alternatives were established and their applicability for OSAscreening was evaluated. The discussed methods includetime-basedapproaches(D-index),non-linearanalysis(central tendency measure, approximate entropy), and spec-tral methods (Welch transform, wavelet transform). When applied to 192 data sets (132 male, 60 female, 47.9"15.5years, BMI 27.4"6.5 kg/m2) these methods showed goodcorrelation with clinical findings. When discriminatingbetween non-OSA and OSA patients the approaches underinvestigation yield sensitivity values between 96.6% and100% and specificity values between 97.4% and 100%. Particularly spectral methods could provide parameters for anoptimized OSA screening based on nocturnal pulse oximetry.