Ring-type Pulse Oximeter for Evaluation for Sleep Assessment Study

Inclusion Criteria: * Age between 18 to 80 years old. Ideally balanced for sex and age (18 to 80 years old) * no more than 75% of subjects in one bin of: (male, female) * no more than 50% of subjects in one age-group (18-29, 30-39, 40-49, 50-59, 60-80) * Patients with OSA symptoms (snoring, excessive daytime sleepiness or witnessed apnea, etc.) * Without any unstable medical or psychiatric co-morbidities that would be expected to interfere with the study. * If taking any medication, must be on a stable dose of medication for a month * Able to read and understand English Exclusion Criteria: * Presence of any significant systemic or unstable medical condition which could lead to difficulty complying with the protocol, suicidality, current regular use of psychiatric medications, opiates, or thyroid medications, dementia, current substance abuse, post-traumatic or psychotic disorders, bipolar disorder; any significant neurologic disease, including possible and probable dementia, Parkinson's or Huntington's disease, brain tumor, progressive supranuclear palsy, seizure disorder, subdural hematoma, multiple sclerosis, history of significant head trauma, history of alcohol or substance use disorder within the past 2 years (DSM V criteria); * If positive airway pressure (PAP) titration study or split night study (diagnostic and PAP titration study combined)