Prospective Use of Awake Endoscopy for Inspire Activation

The aim of this study is to examine a new method of device configuration for the Inspire upper airway stimulator. First, the investigators will attempt to determine optimal configuration by quantifying changes in upper airway size with different implant configurations using awake nasal endoscopy. The configuration/voltage that results in the greatest increase in upper airway size and is tolerated by the patient will be selected. Participants will then undergo a sleep study so that increased airway size may be correlated with changes in sleep study parameters including AHI and oxygen desaturation index (ODI). Airway size and sleep study parameters using the standard device configuration (+-+)/voltage will be compared to airway size and sleep study parameters using the test, or "optimal," configuration/voltage to determine the usefulness of awake endoscopy in activation of the Inspire device.

Awake endoscopic exam will be performed to measure airway size in the retropalatal and retroglossal upper airway regions using different Inspire implant configurations and voltages.

Awake endoscopic exam will be performed to measure airway size in the retropalatal and retroglossal upper airway regions using different Inspire implant configurations and voltages. The optimal test configuration determined on endoscopy will be tested during a sleep study and compared to the standard-of-care device configuration, with improvements in sleep study outcomes indicating that awake endoscopy is useful during Inspire implant activation.

Distribution of Electrode Configurations Resulting in Greatest Retropalatal Expansion Among Cohort Subjects

The hypoglossal nerve stimulator has a triode (three electrodes) that is wrapped around the nerve. Each electrode can be configured to either "Off," "Positive," or "Negative." For each electrode configuration we determined the percentage of patients with the greatest retropalatal cross-sectional area resulting from stimulation.

Inclusion Criteria: Patients with moderate to severe OSA who have undergone Inspire UAS implantation by the principal investigator Must have symptoms of OSA prior to Inspire implantation AHI between 15 and 65, where central and mixed apnea is 25% or more, and the level of collapse is in the soft palate area BMI less than 32 Age 18 or above Exclusion Criteria: Significant central sleep apnea Presence of other sleep disorders History of neurologic or neuromuscular disease Historical or present substance abuse Bleeding disorders Autoimmune diseases that increase risk of nasal trauma such as Wegener's, Sarcoidosis, etc. Pregnancy