Operating under the UC San Diego School of Medicine's Division of Pulmonary, Critical Care, Sleep Medicine and Physiology, the Hillcrest Pulmonary and Sleep Research Laboratory occupies Room 113 of the Clinical Teaching Facility at 214 Dickinson Street. Overnight polysomnography studies recruit subjects with obstructive sleep apnea, COPD, and chronic-pain-opioid populations for trials examining CPAP alternatives and breathing control, drawing pulmonology referrals from clinical faculty including Dr. Jess J. Mandel, MD. Active protocols test pharmacologic adjuncts to CPAP, non-invasive ventilation in COPD overlap syndrome, and the metabolic and cardiovascular consequences of untreated apnea. Cardiac arrhythmia patients with comorbid sleep-disordered breathing are co-enrolled with Jigar D. Patel, DO - San Diego Heart Rhythm Center when atrial fibrillation overlaps the sleep apnea phenotype. The most demanding protocol involves controlled hypoxia and hypercapnia exposure studies that map ventilatory drive in patients with chronic respiratory failure.