Hypoglossal Nerve Stimulation (HGNS)
HGN is tried as one of the recent treatment of obstructive sleep apnea (OSA)

During non-REM deep sleep, all the muscles in the body relax partially, whereas in REM sleep, all the muscles are relaxed completely. In sleep apnea patients, this partial and total muscle relaxation leads to repeated obstructions and arousals.
The hypoglossal nerve supplying the genioglossus muscles in turn controls muscles in the upper airway, ensuring they keep the airway open. Stimulation of the branch of the Hypoglossal nerve caused protrusion and contra lateral deviation of the tongue.
This pacemaker-like device monitors the patient’s breathing patterns and is activated during sleep to stimulate the hypoglossal nerve, timed to the patient’s own respiration.

Base of tongue factor is one of the reason for failure in my surgical patients-Laser and Coblator surgery. I have tried debulking base of tongue with Coblator and helped to some extent.
HG nerve stimulation alone will not cure Sleep apnea, additional procedures may need to be performed, since the tongue base isn’t the only area of obstruction.