Ali Azarbarzin

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In this paper, an automatic and unsupervised snore detection algorithm is proposed. The respiratory sound signals of 30 patients with different levels of airway obstruction were recorded by two microphones: one placed over the trachea (the tracheal microphone), and the other was a freestanding microphone (the ambient microphone). All the recordings were(More)
Snoring sounds vary significantly within and between snorers. In this study, the variation of snoring sounds and its association with obstructive sleep apnea (OSA) are quantified. Snoring sounds of 42 snorers with different degrees of obstructive sleep apnea and 15 non-OSA snorers were analyzed. The sounds were recorded by a microphone placed over the(More)
This paper presents the results of our study on investigating the acoustical properties of snoring sounds (SS) recorded by two microphones (one over trachea and one hung in the air within 30-50 cm away from the subject) in relation to sleep apnea. Several features were extracted from SS segments of 50 snorers with different Apnea-Hypopnea Index (AHI). We(More)
In a multidimensional feature space, the snoring sounds can extend from a very compact cluster to highly distinct clusters. In this study, we investigated the cause of snoring sound’s variation within the snorers. It is known that a change in body position and sleep stage can affect snoring during sleep but it is unclear whether positional, sleep state, and(More)
Tracheal respiratory sound analysis is a simple and non-invasive way to study the pathophysiology of the upper airway and has recently been used for acoustic estimation of respiratory flow and sleep apnea diagnosis. However in none of the previous studies was the respiratory flow–sound relationship studied in people with obstructive sleep apnea (OSA), nor(More)
In this study, an automatic and online snore detection algorithm is proposed. The respiratory sound signals were recorded simultaneously with Polysomnography (PSG) data during sleep from 20 patients (10 simple snorers and 10 OSA patients). The sound signals were recorded by two tracheal and ambient microphones. The potential snoring episodes were identified(More)
STUDY OBJECTIVES The visual appearance of cortical arousals varies considerably, from barely meeting scoring criteria to very intense arousals. Arousal from sleep is associated with an increase in heart rate (HR). Our objective was to quantify the intensity of arousals in an objective manner using the time and frequency characteristics of the(More)
STUDY OBJECTIVES Arousals from sleep vary in duration and intensity. Accordingly, the physiological consequences of different types of arousals may also vary. Factors that influence arousal intensity are only partly understood. This study aimed to determine if arousal intensity is mediated by the strength of the preceding respiratory stimulus, and(More)
STUDY OBJECTIVES Arousal intensity and heart rate (HR) response to arousal during polysomnography (PSG) vary considerably between patients with sleep disorders. Our objective was to determine the range of these arousal characteristics in healthy young adults and whether they are consistent on repeated testing. DESIGN Post hoc analysis of 56 preexisting(More)