Inclusion Criteria:  No history of self-reported cardiovascular or neurological issues Must be a current PAP machine user. Must have used PAP machines for more than 4 months. Must be at least 18 years old Must be able to comply with all study requirements as outlined in the consent form Must be able to understand English and be willing to provide written informed consent For all nights of the study, participant must be willing to lend their personal PAP device for inspection.  Exclusion Criteria:  Subjects actively using bi-level PAP or require oxygen therapy History of severe cardiovascular disease, including NYHA Class III or IV heart failure, CAD with angina, or MI/stroke within past 6 months Subjects who are medically complicated or who are medically unstable (i.e. cancer, dementia, unstable cardiac or respiratory disease, or unstable psychiatric illness) Potential sleep apnea complications that in the opinion of the clinician may affect the health and safety of the participant Subjects exhibiting any flu-like or any upper airway tract infection symptoms at the time of assessment Pregnant (confirmed verbally) Inability or unwillingness of individual to give written informed consent Has received bariatric surgery