Inclusion Criteria:  Provision of signed and dated informed consent form. Age 18-80 Clinically assessed and suspicious for OSA  Exclusion Criteria:  Full night PAP titration study On home O2, noninvasive ventilator, diaphragmatic pacing, or any form of nerve stimulator Having atrial fibrillation-flutter, pacemaker/defibrillator, LVEF < 55%, left ventricular assist device (LVAD), or status post cardiac transplantation Patients taking narcotics Recent hospitalization or recent surgery in the past 30 days Unstable cardiopulmonary status on the night of the study judged to be unsafe for sleep study by the sleep tech and/or the on-call sleep physician  An individual who meets the above criteria but fails to have at least 4 hours of technically valid sleep based on BLS-100 in a diagnostic study or at least 3 hours of technically valid sleep during the diagnostic portion of a split night study will be excluded from statistical analyses.