CL-CCC2022 Nyxoah ACCCESS Study

Inclusion Criteria:
*  1. Age from 22 to 75 years (inclusive). Participant cannot be under guardianship, under curatorship or under judicial protection. 2. Body mass index (BMI) ≤ 32 kg/m2. 3. Positive cricomental space (≥ 0 cm). The cricomental space is the distance between the neck and the bisection of a line from the chin to the cricoid membrane when the head is in a neutral position. 4. Has either not tolerated, has failed or refused positive airway pressure (PAP) treatments. 5. Moderate to severe OSA (15≤AHI4≤65 where combined central and mixed AHI\<25% of the total AHI) based on a screening HST and confirmed in Baseline PSG. 6. Complete concentric collapse at the level of the soft palate based on screening DISE. 7. Willing and capable of complying with all study requirements, including specific lifestyle considerations, performing all follow-up visits and sleep studies, evaluation procedures and questionnaires for the whole duration of the trial.
* 

Exclusion Criteria: 1. Inadequately treated sleep disorders other than OSA that would confound functional sleep assessment: 1. Severe chronic insomnia, 2. Insufficient sleep syndrome (\<6 hours sleep per night), 3. Narcolepsy, 4. Restless legs syndrome, 5. REM behavior disorder, 6. Others deemed sufficient disorders that would confound functional sleep assessment in the judgment of the investigator. 2. Taking medications that may alter consciousness, the pattern of respiration, or sleep architecture as determined by the investigator. 3. Major anatomical or functional abnormalities that would impair the ability of the Genio® System to treat OSA: 1. Craniofacial abnormalities narrowing the airway or the implantation site, 2. Palatine tonsil size 3+ or 4+ by the Brodsky Classification, 3. Fixed upper airway obstructions (tumor, polyps, nasal obstruction), 4. Congenital malformations in the airway, 5. Hypoglossal nerve palsy (bilateral limited tongue movement, or unilateral unintended tongue deviation during protrusion), 6. Existing swallowing difficulty as measured by a score of ≥3 on the EAT-10 questionnaire 7. Others deemed sufficient to impair the ability of the Genio® System to treat OSA in the judgment of the investigator. 4. Significant comorbidities that contraindicate surgery or general anesthesia: 1. Revised Cardiac Risk Index Class III or IV, 2. Persistent uncontrolled diagnosed hypertension despite medications, 3. Coagulopathy or required anticoagulant medications (such as warfarin, clopidogrel (Plavix) or similar; prophylactic aspirin not exclusionary) that cannot be safely stopped in the perioperative period, Subjects meeting any of the following criteria will be excluded from participation in this study: 1. Inadequately treated sleep disorders other than OSA that would confound functional sleep assessment: 1. Severe chronic insomnia, 2. Insufficient sleep syndrome (\<6 hours sleep per night), 3. Narcolepsy, 4. Restless legs syndrome, 5. REM behavior disorder, 6. Others deemed sufficient disorders that would confound functional sleep assessment in the judgment of the investigator. 2. Taking medications that may alter consciousness, the pattern of respiration, or sleep architecture as determined by the investigator. 3. Major anatomical or functional abnormalities that would impair the ability of the Genio® System to treat OSA: 1. Craniofacial abnormalities narrowing the airway or the implantation site, 2. Palatine tonsil size 3+ or 4+ by the Brodsky Classification, 3. Fixed upper airway obstructions (tumor, polyps, nasal obstruction), 4. Congenital malformations in the airway, 5. Hypoglossal nerve palsy (bilateral limited tongue movement, or unilateral unintended tongue deviation during protrusion), 6. Existing swallowing difficulty as measured by a score of ≥3 on the EAT-10 questionnaire 7. Others deemed sufficient to impair the ability of the Genio® System to treat OSA in the judgment of the investigator. 4. Significant comorbidities that contraindicate surgery or general anesthesia: 1. Revised Cardiac Risk Index Class III or IV, 2. Persistent uncontrolled diagnosed hypertension despite medications, 3. Coagulopathy or required anticoagulant medications (such as warfarin, clopidogrel (Plavix) or similar; prophylactic aspirin not exclusionary) that cannot be safely stopped in the perioperative period, 4. Degenerative neurological disorder (i.e., Parkinson's disease, Alzheimer's disease), 5. Acute illness or infection, 6. Any other chronic medical illness or condition that contraindicates a surgical procedure or general anesthesia in the judgment of the investigator. 5. Diagnosed psychiatric disease (e.g., psychotic illness, uncontrolled major depression or acute anxiety attacks) that prevents participant compliance with the requirements of the investigational study testing, 6. Substance or alcohol abuse history within the previous 3 years. Alcohol and substance abuse are defined as follows: i. Alcohol: no days with less than 3 or 4 standard drinks for women and men respectively ii. Substance: the use of any substance in an amount unapproved by the investigator or considered illegal. The drugs most commonly abused include cocaine, marijuana, heroin (or substitution treatment), prescription drugs (especially painkillers), methamphetamines, and various other illegal substances. 7. Life expectancy of less than 12 months. 8. Prior surgery or treatments that could compromise the effectiveness of the Genio® System: 1. Airway cancer surgery or radiation, 2. Mandible or maxilla surgery in the previous 5 years (not counting dental treatments), 3. Other upper airway surgery to remove obstructions related to OSA in the previous 3 months (e.g., uvulopalatopharyngoplasty (UPPP), tonsillectomy, nasal airway surgery), 4. Prior hypoglossal nerve stimulation device implantation. 9. Has an Active Implantable Medical Device (AIMD) even if the device can be temporarily turned off. 10. Participation in another clinical study with an active treatment arm. 11. Plan to become pregnant, currently pregnant, or breastfeeding during the study period.