Obstructive sleep apnea (OSA) is when a person stops breathing many times while sleeping. Surgery can help, and doctors use a procedure called Drug Induced Sleep Endoscopy (DISE) to see how the throat closes during sleep. Lung volume (how much air your lungs hold) may affect OSA, but this isn't well understood. This study will look at how lung volume affects the throat during DISE. Participants will have DISE done as part of their usual surgery check-up for OSA. They will be in one of two groups: one uses a "turtle shell" ventilator to change lung volume, the other uses a neck device to stimulate a nerve that helps breathe. Both groups will have lung function tests. The study aims to improve surgical success prediction and develop better treatments for OSA.

• Study participants will have DISE, which is part of their surgical evaluation.
• Participants will be assigned to either a ventilator or nerve stimulation group.
• Must be adults (18+), interested in surgery for OSA, and able to give consent.