Inclusion Criteria:
1. Subject is aged ≥ 18 years old
2. Subject is willing and able to provide informed consent
3. Subject is geographically stable
4. Subject does not have access to alternative Sleep Disordered Breathing treatments (e.g. oral appliances, and/or behavioral treatments)
5. Subject has an Apnea-Hypopnea Index (AHI) score ≥15 \< 100 events per hour on Screening PSGs (under AASM 4%) based on in-lab polysomnography studies
Exclusion Criteria:
1. Subject is currently implanted with another active implantable device.
2. Subject is actively enrolled in another premarket investigational study (medical device or drug) unless approved by Sponsor in writing.
3. Subject is considered vulnerable such as incarcerated or cognitively impaired.
4. Subject is taking opioids, narcotics, sleep or psychotic medications or supplements that in the opinion of the investigator may alter consciousness, the pattern of respiration, sleep architecture, or with known effect on sleep-wake function or alertness.
5. Any reason for which, in the judgment of the investigator, the subject is considered to be a poor study candidate, which may include, but is not limited to: any uncontrolled neurological, medical, social, or psychological problems that could complicate the required procedures and evaluations of the study ((e.g. uncontrolled hypertension, unstable angina, uncompensated heart failure or COPD, major depression, Parkinson's disease, epilepsy)
6. Subject has previous upper respiratory tract (URT) surgery (e.g., uvula, soft palate or tonsils) within 60 days prior to Screening PSG.
7. Subject has a need for chronic supplemental oxygen therapy for any reason or a PaO2 \<70 mm Hg
8. Subject has other sleep disorders or sleep hygiene behaviors that confound functional assessments of sleepiness and/or overnight PSG Study outcomes (e.g. Narcolepsy with cataplexy, idiopathic hypersomnolence, insomnia, REM sleep behavior disorder, or sleep movement disorders, such as restless leg syndrome or periodic limb movement, producing sleep disturbances unrelated to OSA.)
9. Subject has severe chronic kidney disease (GFR \< 30)
10. Subject has currently excessive use of alcohol, tobacco, caffeine, or recreational drugs.
11. Subject is unwilling or unable to refrain from consumption of alcoholic beverages for 24 hours prior to the start of each PSG study.
12. Subject has a BMI \> 40 kg/m2
13. Subject has an active systemic infection
14. If female, subject is pregnant at the time of enrollment or planning to become pregnant during the study time period (must have a negative serum or urine pregnancy test within 14 days prior to enrollment)
15. Subject has a tonsil size 3 or 4 based on the tonsil grading system
16. Subject has documented history of Phrenic nerve palsy or asymmetry of the diaphragm
17. Subject has any trauma to the upper airway that interferes with limited tongue movement or inability to move the tongue, tongue dysfunction, atrophy, hypertrophy, fasciculation, or problems swallowing or speaking
18. Subject has severe mandibular deficiency/retrognathia or syndromic craniofacial abnormalities.
19. Subject has previous surgical resection or radiation therapy for cancer or congenital malformations in the larynx, tongue, or throat.
20. Subject has an oxygen saturation (SaO2) \>10% falls index \> 15 events per hour on Screening PSGs
21. Subject has \>25% central apnea events as a proportion of the sum of apnea and hypopnea events per hour on Screening PSGs (up to 3 patients with CAI+MAI ≥ 25% may be included)
22. Subject has sleep Efficiency \< 80%
