Obstructive Sleep Apnea (OSA) is a common respiratory disorder during sleep. Apnea is cessation of airflow to the lungs, which lasts for at least 10 seconds accompanied by more than 4% drop of the blood's Oxygen saturation. Polysomnography during the entire night is the Gold Standard diagnostic method of OSA. It's high cost and inconvenience for patients persuaded researchers to seek alternative OSA detection methods. This thesis proposes a technique for assessment of OSA during wakefulness. We recorded tracheal breath sounds of 17 non-apneic individuals and 35 people with various degrees of OSA severity in supine and upright positions during nose and mouth breathing at medium flow rate. We calculated the power spectrum, Kurtosis, and Katz fractal dimensions of the recorded signals. Then, we reduced the number of characteristic features to two. We classified the participant into severe OSA and non-OSA groups as well as non-OSA or mild vs. moderate and severe OSA groups. The results showed more than 91 and 83% accuracy; for the two types of classification. Once veri ed on a larger population, the proposed method may be used as a simple and non-invasive screening tool for assessment of OSA during wakefulness.

Establishing healthy sleep-wake patterns early in infancy is vitally important as sleep problems can persist. Behavioural sleep interventions such as the parental presence procedure are well established and have been found to improve infant sleep as determined by parent report. The exact nature of this improvement is, however, unclear. Sleep consolidation, sleep-state organisation, and self-soothing are thought likely to change after intervention; however, no known research has comprehensively determined which of these variables change as infant sleep changes in response to intervention. Three participants aged between 7 to 11 months who met the criteria for Infant Sleep Disturbance (ISD) were referred by a Health Centre and the parental presence behavioural sleep intervention was implemented. Parental report and videosomonography (VSG) data were used to measure sleep before and after intervention. While parental report is limited in that parents can only report what they can hear and/or see, VSG offers a tool that can be used to measure sleep-state organisation, state changes, and periods when the infant is awake and quiet. The present research found that infants’ sleep became more consolidated resulting in fewer sleep-wake transitions and night wakings. Infants who had difficulties initiating sleep on their own also demonstrated decrease in Sleep Onset Delay (SOD). Furthermore, infants were found to sleep through a greater number of sleep-state transitions and sleep for a greater duration of time before waking. Collectively this research provides some evidence that changing parental behaviours to those that promote self-initiation through self-soothing and consistency, can change sleep-state organisation and improve self-soothing.

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Obstructive Sleep Apnea (OSA) is a common respiratory disorder during sleep. Apnea is cessation of airflow to the lungs, which lasts for at least 10 seconds accompanied by more than 4% drop of the blood's Oxygen saturation. Polysomnography during the entire night is the Gold Standard diagnostic method of OSA. It's high cost and inconvenience for patients persuaded researchers to seek alternative OSA detection methods. This thesis proposes a technique for assessment of OSA during wakefulness. We recorded tracheal breath sounds of 17 non-apneic individuals and 35 people with various degrees of OSA severity in supine and upright positions during nose and mouth breathing at medium flow rate. We calculated the power spectrum, Kurtosis, and Katz fractal dimensions of the recorded signals. Then, we reduced the number of characteristic features to two. We classified the participant into severe OSA and non-OSA groups as well as non-OSA or mild vs. moderate and severe OSA groups. The results showed more than 91 and 83% accuracy; for the two types of classification. Once veri ed on a larger population, the proposed method may be used as a simple and non-invasive screening tool for assessment of OSA during wakefulness.

Early-onset major depressive disorder (MDD) is associated with significant morbidity in adolescence. The interview-dependent diagnostic process used in psychiatry leaves a subset of adolescents with MDD undiagnosed. Sleep disturbances are a central feature of depression and adolescence is a period of rapid change in sleep physiology. The aim of this study was to test physiological features of sleep and circadian rhythms as markers of adolescent MDD. Adolescents completed a two-week protocol that included a formal psychiatric interview, polysomnographic (PSG) assessment, actigraphy, salivary melatonin sampling, and holter monitoring. Depressed adolescents (n = 18) differed from controls (n = 15) on features of sleep macroarchitecture measured by PSG, and on autonomic nervous system functioning measured by 24-hour heart rate variability. Depressed adolescents had shorter REM latency and decreased stage 4 sleep. Adolescents with MDD also showed decreased parasympathetic activity over 24-hours and during the day, and decreased sympathetic activity during the night.

Thesis (MPsych(Clin))--University of South Australia, 1998

Methadone is a long acting mu-opioid and is the most effective treatment for heroin addiction. However, opioids depress respiration and methadone maintenance treatment (MMT) patients have a higher mortality rate than the general population. Teichtahl et al conducted a pilot study and found 6 out of 10 MMT patients had central sleep apnea (CSA). But no definite conclusions were made regarding the prevalence and possible pathogenesis of CSA in the patients due to the small sample size and lack of blood toxicology data. The present project aims to confirm the preliminary results and further quantify the sleep disordered breathing (SDB) in stable MMT patients and to delineate the pathogenesis involved. (For complete abstract open document)

Master of Science / In this thesis, a recently developed physiologically-based model of the sleep-wake switch is analyzed and applied to a variety of clinically-relevant protocols. In contrast to phenomenological models, which have dominated sleep modeling in the past, the present work demonstrates the advantages of the physiologically-based approach. Dynamical and linear stability analyses of the Phillips-Robinson sleep model allow us to create a general framework for determining its response to arbitrary external stimuli. The effects of near-stable wake and sleep ghosts on the model’s dynamics are found to have implications for arousal during sleep, sleep deprivation, and sleep inertia. Impulsive sensory stimuli during sleep are modeled modeled according to their known physiological mechanism. The predicted arousal threshold variation matches experimental data from the literature. In simulating a sleep fragmentation protocol, the model simultaneously reproduces the body temperature and arousal threshold variation measured in another existing clinical study. In the second part of the thesis, we simulate sleep deprivation by introducing a wake-effort drive that is required to maintain wakefulness during normal sleeping periods. We interpret this drive both physiologically and psychologically, and demonstrate quantitative agreement between the model’s output and experimental subjective fatigue-related data. As well as subjective fatigue, the model is simultaneously able to reproduce adrenaline excretion and body temperature variations. In the final part of the thesis, the model is extended to include the orexinergic neurons of the lateral hypothalamic area. Due to the dynamics of the orexin group, the extended model exhibits sleep inertia, and an inhibitory circadian projection to the orexin group produces a postlunch dip in performance – both of which are well-known behavioral features. Including both homeostatic and circadian inputs to the orexin group, the model produces a waking arousal variation that quantitatively matches published clinical data.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 70 p. : ill. Includes abstract. Includes bibliographical references (p. 37-45).

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 99-111). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.