The aim of this study is to assess the efficacy of transcutaneous electrical stimulation of the upper airway muscles in patients with obstructive sleep apnea.

Inclusion criteria:

• Obstructive apnea-hypopnea index > 15 events/hour
• Patients who do not tolerate or do not accept positive airway pressure therapy

Main exclusion criteria:

• Body mass index < 18.5 or > 32 kg/m2
• Unable or incapable of providing informed written consent
• Unwilling or incapable of returning to all follow-up visits and sleep studies, including evaluation procedures and filling out questionnaires
• Significant co-morbidities making the patient unable or inappropriate to participate in the trial