This research area includes sleep apnea in adolescents suffering from obesity, sleep related breathing disorders in infancy, and obstructive sleep apnea in individuals with craniofacial differences. More specifically, the areas of focus include:
Model-based phenotyping of sleep-related breathing disorders in pediatric obesity
Clinical studies of sleep-disordered breathing (SDB) have generally focused on upper airway collapsibility as the primary factor responsible for the development of the disorder. However, recent studies suggest that other factors that affect dynamic changes in upper airway patency, such as chemoreflex control and state dependence, also play important roles. Moreover, the pool of subjects with obesity-related SDB display a large variation of polysomnographic and clinical characteristics. We hypothesize that this diversity in behavior results from the existence of different underlying physiological mechanisms, and that phenotyping using a quantitative model in conjunction with dynamic imaging of the upper airway may allow us to better delineate the mechanistic differences.
(PIs: Michael C.K. Khoo, Sally Ward, Krishna Nayak)
Model-based stability assessment of ventilatory control in overweight adolescents with obstructive sleep apnea during NREM sleep.
Nava-Guerra L, Tran WH, Chalacheva P, Loloyan S, Joshi B, Keens TG, Nayak KS, Davidson Ward SL, Khoo MC. J Appl Physiol (1985). 2016 Jul 1;121(1):185-97. PMID: 27174926
Pediatric sleep-related breathing disorders: advances in imaging and computational modeling.
Davidson Ward SL, Amin R, Arens R, Zhongping Chen, Davis S, Gutmark E, Superfine R, Wong B, Zdanski C, Khoo MC. IEEE Pulse. 2014 Sep-Oct;5(5):33-9. doi: 10.1109/MPUL.2014.2339293. PMID: 25437473
Autonomic markers of metabolic dysfunction in sleep apnea and obesity
Diet, physical activity, glucose-insulin control and autonomic activity are tied together in a delicate balance that, if disrupted, can lead to obesity and obesity-related disorders. Sleep apnea, which is highly prevalent in obesity, can also contribute independently to autonomic imbalance and insulin resistance. We are conducting experimental and computational modeling studies aimed at elucidating and quantifying the relationships among autonomic dysfunction, insulin resistance and severity of sleep apnea in overweight subjects. These studies employ a “minimal modeling” approach to extract information characterizing autonomic function from noninvasive cardiorespiratory measurements, along with blood sampling to assess glucose-insulin regulation.
(PIs: Michael C.K. Khoo, Sally Ward)
Understanding the metabolic syndrome: a modeling perspective.
Khoo MC, Oliveira FM, Cheng L. IEEE Rev Biomed Eng. 2013;6:143-55. PMID: 23232440
Model-based assessment of cardiovascular autonomic control in children with obstructive sleep apnea.
Chaicharn J, Lin Z, Chen ML, Ward SL, Keens T, Khoo MC. Sleep. 2009 Jul;32(7):927-38. PMID: 19639756