Severe sleep apnea patients will undergo two polysomnographies (PSG), one with kinesthetic stimulation triggered on the detection of apneas and hypopneas (treated night ) and the other without kinesthetic stimulation (non-treated night ). Comparison of apnea and hypopnea indices (AHI) and of oxygen saturation between the treated and non-treated night will be taken as indicators to quantify the performance of this potential new therapy.