OPTISAS a new method to analyse patients with Sleep Apnea Syndrome Adrien UGON ad , Carole PHILIPPE a , Slawomir PIETRASZ a , Jean-Gabriel GANASCIA d , Pierre P LEVY abc1 a Hôpital Tenon( Assistance Publique Hôpitaux de Paris), France ; b INSERM, UMR-S707, Paris, F-75012; c Université Pierre et marie Curie –Paris 6, UMR S 707, Paris, F75012 d LIP6, Université Pierre et marie Curie –Paris 6, Paris, F75015 Abstract: OPTISAS is a visualization method that allows describing very precisely a patient with Sleep Apnea Syndrome. Using the events scored by the physician, our method gives a set of graphs that are a detailed representation of the condition, sleep stage and position, in which the events occur. This helps for the diagnosis. This is possible thanks to the application of Generalized Caseview method. The method proceeds in two steps, defining the reference frame and using this reference frame to visualize data. The reference frame is built by using a supin/unsupine binary criterion, a six type event criterion and a sleep stage ordinal criterion. The main result is the visualization of the indexes (average number of events by hour) associated with the events. This allows a more accurate diagnosis showing the precise influence of the position and of the sleep stage on the events. Keywords: Generalized Caseview; Information visualization; Sleep Apnea Syndrome; Polysomnography; Diagnosis; Signal Processing 1. Introduction Sleep Apnea Syndrome (SAS) is a real public health problem. The sleep apnea – hypopnea syndrome occurs in 2-4% of the middle aged population [1], causing daytime sleepiness, cognitive deficits and road traffic accidents. Its association with increased cardiovascular [2] and cerebrovascular morbidity [3] has been clearly recognized. Young and colleagues estimated that 2% of women and 4% of men meet the criteria for the clinical syndrome of sleep-disordered breathing. Caring of these patients at an early stage is very important for treatment efficiency and complication prevention. The main existing exploratory means is the polysomnography. This examination is an overnight multichannel recording dedicated to the accurate diagnosis of sleep disorders. Due to 1 Address for correspondence Pierre Lévy Hôpital Tenon, Public Health Department 4, rue de la chine, 75970 Paris cedex 20, France Email : pierre.levy@tnn.aphp.fr eHealth Beyond the Horizon – Get IT There S.K. Andersen et al. (Eds.) IOS Press, 2008 © 2008 Organizing Committee of MIE 2008. All rights reserved. 547