Mechanisms of Upper Airway Obstruction

Study A Inclusion Criteria: • Scheduled to undergo DISE as part of routine clinical standard of care. Study B Inclusion Criteria: * Adults (≥ 22yrs) willing and capable of providing informed consent * Implanted with the MRI-conditional Inspire hypoglossal nerve stimulator (Model 3028 or later) * Compliant with Inspire therapy (\> 20 hours/week over 2+ weeks) as a standalone treatment for sleep-disordered breathing * Inspire remote model 2500 or later. Study B Exclusion Criteria: * MRI contraindications (claustrophobia, ferromagnetic implants/foreign bodies, etc.) * Inspire Implant Model 3024 * Inspire Remote Model 3032 * Patients who have fallen asleep while during resulting in an accident or "near miss" accident within 1 year prior to device implantation. * Inability to sleep in the supine position (by self-report) * History of severe difficulty initiating or maintaining sleep in the laboratory * Pregnant women