Efficacy Investigation of the Medical Device Apneal® on Smartphone for Sleep Apnea-Hypopnea Syndrome Diagnosis

The goal of this clinical trial is to evaluate the effectiveness of the Apneal® app in diagnosing sleep apnea syndrome (SAS) in adults who require polysomnography (PSG) as part of routine care. The main questions it aims to answer are: * Can Apneal® accurately classify the SAS severity into four categories (normal: AHI \< 5, mild: 5 ≤ AHI \< 15, moderate: 15 ≤ AHI \< 30, and severe: AHI ≥ 30) compared to PSG ? * How does Apneal® perform in estimating the Apnea-Hypopnea Index (AHI), detecting sleep stages, differentiating between central and obstructive apneas, and identifying patient movements? Participants will: * Wear the Apneal® app-equipped smartphone and undergo PSG during a full night of sleep at home. * Complete several questionnaires assessing sleep symptoms and experience with the Apneal® app.