Nonalcoholic fatty liver disease (NAFLD) afflicts approximately a quarter of the world’s general population and more than half of the world’s obese population. The disease is characterized by a spectrum of liver pathologies, ranging from simple steatosis or the accumulation of fat within hepatic tissue to steatohepatitis comprised of inflammation and fibrosis, also known as NASH. Simple steatosis is relatively asymptomatic and is considered benign, but NASH poses great risk for advanced forms of liver disease, such as cirrhosis and hepatocellular cancer. Obstructive sleep apnea(OSA) is a respiratory disorder involving the recurrent collapse of the upper airway during sleep. Consequently, the patient experiences constant arousals due to constant blockage followed reopening of the airway. Aside from poor quality and disruption of sleep, chronic intermittent hypoxia (CIH) is also present during OSA. The presence of CIH leaves many vital organs deprived of adequate oxygen to carry out normal physiological function. In response to this hypoxic state, the body upregulates many transcription factors, many of which control inflammatory processes. In recent studies, chronic and recurrent hypoxia generated from OSA has been implicated in the onset and progression of NAFLD. The pathogenesis of NAFLD is believed to be associated with metabolic imbalances, mainly obesity and insulin resistance, both of which also overlap with OSA. These conditions are the main factors in predisposing a patient suffering from OSA to the effects of CIH. Multiple lines of evidence suggest that CIH may accelerate the development of NAFLD through 1) Lipolysis of hepatic adipose tissue and increased hepatic free fatty acids; 2) Upregulation of lipid biosynthetic through CIH; 3) Upregulation of hypoxia-inducible factor 1-alpha by CIH inducing liver inflammation and fibrosis. The primary focus of this thesis will attempt to determine a possible link between OSA and NAFLD. Through citation of prior scientific studies, it will formulate the theory of OSA as a predisposing factor in the heightened risk of NAFLD pathogenesis and development to more severe, terminal stages. Primarily, the review of literature will highlight the metabolic imbalances of obesity and insulin resistance and how each is related to OSA and NAFLD. Ultimately, deposition of fat and inflammation triggered through various chemical factors connected to OSA will depict both the generation and progression of NAFLD.

Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η ανάπτυξη εφαρμογής για λειτουργικό σύστημα Android, για την ανίχνευση της υπνικής άπνοιας. Αρχικά μελετάται η υπνική άπνοια σαν υπνική διαταραχή, οι διάφορες κατηγορίες της, συμπτώματά της και οι τρόποι θεραπείας της. Στη συνέχεια γίνεται αναφορά στις φορητές ηλεκτρονικές συσκευές για τη διάγνωση αυτής της ασθένειας καθώς και τα βασικά κριτήρια που πρέπει να πληρούν οι συσκευές αυτές, όπως αυτά διαμορφώθηκαν από διεθνείς οργανισμούς που ασχολούνται με την μελέτη των ασθενειών του ύπνου. Έπειτα παρουσιάζεται το λειτουργικό σύστημα Android, αναλύεται η αρχιτεκτονική του καθώς και η αρχιτεκτονική των εφαρμογών που Η υπνική άπνοιααναπτύσσονται για αυτό το λογισμικό. Παρουσιάζεται η πλατφόρμα ανάπτυξης Eclipse καθώς και οι επιπρόσθετες δυνατότητες που αποκτά με την προσθήκη του πακέτου Android SDK. Τέλος παρουσιάζονται βασικά παραδείγματα εφαρμογών ώστε να μπορεί ο αναγνώστης να εξοικειωθεί με βασικές δομές που χρησιμοποιήθηκαν για την ανάπτυξη της παρούσας εφαρμογής. Παρουσιάζεται επίσης η λογική της εφαρμογής που αναπτύχθηκε. Βασικές αρχές για την ψηφιακή επεξεργασία σήματος όπως αυτές χρησιμοποιήθηκαν για την επεξεργασία του σήματος της αναπνοής που αναλύεται αυτόματα από την εφαρμογή και τέλος ο μηχανισμός εξαγωγής του τελικού συμπεράσματος, δηλαδή ο τρόπος με τον οποίο η εφαρμογή πραγματοποιεί την τελική της διάγνωση. / The subject of this diploma thesis is the development of an Android application, which is capable to diagnose sleeping apnea. Firstly, there is an extended presentation of sleeping apnea as a sleep disorder. The categories in which sleeping apnea can be divided. Its symptoms and the ways of healing this disorder. Moreover, portable devices for the diagnosis of this disorder are been represented and referred the goals that these devices have to achieve, as they formed by international organizations, which are occupied with the analysis of sleeping disorders. Then the operating system Android is been analyzed, in the domain of its architecture and the structure of an Android application. Furthermore, eclipse IDE is been represented and the further capabilities that it is gain with the installation of the Android SDK. In the last section of this diploma thesis there are some basic example application, which help the primer to acquaint with the structure that are used in the main program of developed application.

Obstructive sleep apnea (OSA) and asthma are potentially linked at several levels. The pathophysiology of these two conditions seems to overlap significantly, as airway obstruction, inflammation, obesity, and several other factors are implicated in the development of both diseases. Gastroesophageal reflux disease (GERD), cardiovascular complications, obesity itself, and the underlying inflammatory processes are all complex contributory factors that provide hypothetical links. Furthermore, a collateral rise in prevalence of both OSA and asthma has been noticed during the past few years, occurring in association with the emerging epidemic of obesity, a common risk factor for both conditions. OSA and asthma share many other risk factors as well. We propose a hypothetical OSA-asthma relationship that has implications on the diagnosis and management of patients presenting with either condition singly. Clinicians should be aware that OSA might complicate asthma management. Based on this hypothesis, we suggest that the treatment of the individual patient who experiences both asthma and OSA needs to be multidisciplinary and comprehensive. This hypothetical association of asthma and OSA, though described anecdotally, has not been systematically studied. In particular, the influence of continuous positive airway pressure therapy (for sleep apnea) on asthma outcomes (such as quality of life, steroid utilization, emergency room visits) and fatality needs to be studied further.