The goal of this study is to collect raw waveform data for two separate noninvasive methods, both of which may be useful for the assessment of upper airway obstruction.

Inclusion Criteria:

• Patients twenty-one years of age or older

Exclusion Criteria:

• Patient refusal to participate in study
• Patients under 21 (twenty-one) years of age,
• Referring physician's refusal to have his/her patient participate in the study.
• Patients with cardiac dysrhythmia (arrhythmia), including atrial fibrillation, and frequent premature atrial and/or ventricular contractions.
• Inability to obtain a Sotera cuff pressure and/or PPG signals