The objective of this study is to evaluate the safety and preliminary effectiveness of an implantable hypoglossal nerve stimulation system for moderate-to-severe obstructive sleep apnea (OSA).

Inclusion Criteria

1. Age 18 years or older, regardless of sex.
2. Moderate-to-severe obstructive sleep apnea confirmed by polysomnography, with an apnea-hypopnea index of 15 to 100 events per hour.
3. Prior failure of, intolerance to, or unwillingness to continue positive airway pressure therapy.
4. Body mass index ≤40 kg/m².
5. Able to communicate with the investigator, understand the study requirements, and provide written informed consent.
6. Willing and able to comply with study procedures and complete postoperative follow-up visits.

Exclusion Criteria

1. Central and mixed apnea and hypopnea events account for more than 25% of the total apnea-hypopnea index.
2. Presence of obvious fixed upper airway obstruction or obstructive upper airway lesions, including but not limited to tumors or masses, polyps, scar stenosis, or severe nasal septal deviation involving the nasal cavity, nasopharynx, oropharynx, hypopharynx, or larynx, which, in the investigator's judgment, may affect device implantation, treatment effect, or evaluation of the primary effectiveness endpoint.
3. Abnormal hypoglossal nerve function; neurological or neuromuscular disease that may affect upper airway neuromuscular control or tongue movement; or clinically significant dysphagia.
4. Severe cardiopulmonary disease, including but not limited to chronic obstructive pulmonary disease, severe asthma, chronic respiratory failure, myocardial infarction, or severe arrhythmia.
5. Any disease or condition that precludes general anesthesia or may interfere with implantation of the hypoglossal nerve stimulation system.
6. Pregnant or lactating women, or women planning pregnancy during the study period.
7. Any condition that, in the investigator's judgment, makes the participant unsuitable for participation in this study.
8. Participation in another clinical trial within 4 weeks before signing informed consent.
9. Presence of an implanted active medical device that may interact with the investigational hypoglossal nerve stimulation system, affect treatment effectiveness, or compromise participant safety.
10. Unable or unwilling to discontinue other obstructive sleep apnea-related treatments during the study, except for the investigational hypoglossal nerve stimulation system manufactured by Beijing PINS Medical Co., Ltd.