This study will test the hypothesis that the modified positive airway pressure (PAP) device for OSA will be no worse than a market released product in terms of its treatment efficacy, comfort and patient compliance. Patients will have their treatment pressure titrated using polysomnography (PSG) in the sleep laboratory, and then in a random order will spend additional time undergoing PSG using both devices, and using both devices at home for 3 weeks. Data will be collected from the PSG studies, device downloads, independent pressure-flow loggers, and custom questionnaires.