Research Summary

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The cumulative evidence suggests that people with sleep-related breathing disorders, such as sleep apnea, are more likely to develop various forms of cardiovascular disease as well as Type 2 diabetes. Understanding the physiological mechanisms that link sleep apnea to cardiovascular autonomic and metabolic dysfunction forms the primary focus of Dr. Khoo's research interests. Sleep apnea involves the dynamic interaction of three major physiological control systems: respiratory, cardiovascular and sleep regulation - over a longer time scale, glucose-insulin regulation is also affected. To delineate cause from effect in the complex dynamics that arise from these interactions, Dr. Khoo's group employs a combination of "structured" (or parametric) modeling and closed-loop minimal modeling approaches to analyze and interpret physiological data obtained from noninvasive studies in humans. These approaches require the application of control theory, system identification techniques and computer simulation. The Khoo laboratory collaborates closely with physician-scientists and physiologists from Childrens Hospital of Los Angeles, USC Keck School of Medicine and Harvard University. Recent research studies have focused on the issue of phenotyping the various forms of sleep-related breathing disorders in obese children using a combination of computational modeling and dynamic magnetic resonance imaging (in collaboration with Drs. Nayak and Narayanan from the USC Electrical Engineering Department). His laboratory is also working on the development of improved noninvasive methodologies for predicting vaso-occlusive crises in patients with sickle-cell disease.