The goal of this interventional study is to assess the safety and performance of the XII Medical Hypoglossal Nerve Stimulation (HGNS) System in people who have moderate to severe Obstructive Sleep Apnea (OSA).

Participation in this study involves being implanted with a Neurostimulator which provides electrical stimulation of the hypoglossal nerve (HGN). Participants will receive treatment at home during sleep, and participate in sleep studies to track and record the quality of the sleep. Participants will be monitored over the course of the study.

Inclusion Criteria:

• Body Mass Index (BMI) ≤ 32 kg/m2
• AHI of 15-50 events/hour
• Central + mixed apnea index ≤ 25%
• Participants who have either not tolerated, have failed or refused positive airway pressure (PAP)

Exclusion Criteria:

• Pregnancy or breast-feeding.
• Significant upper airway anatomic abnormalities
• Hypoglossal nerve weakness
• Central sleep apnoea condition
• Significant positionally-dependent OSA.
• Complete concentric patterns of soft palate collapse on DISE
• Inadequately treated non-OSA sleep disorder(s).
• Significant co-morbidities or prior surgeries that contra-indicate a surgical procedure or general anesthesia
• Taking medications that in the opinion of the investigator may alter consciousness, the pattern of respiration, or sleep architecture
• Participants on a GLP-1