Severe urinary incontinence is defined as an involuntary urine loss in great quantity. Implantation of an artificial urinary sphincter can overcome this handicap and make the patient recover a normal social life. Today, the prosthesis (AMS 800™) implanted is manufactured by the American Medical System company. It provides good results on human incontinence and has demonstrated its reliability on about 80% of implanted patients. However, surgical revision rate linked to mechanical breakdowns or urethral atrophy, secondary to continuous high pressures exerted on the urethra, remains high. Moreover, the use of this prosthesis is difficult and, then, not adapted to all patients. The purpose of this study is an improvement upon the AMS 800™ system by dynamically regulating the pressure within the cuff in order to maintain an optimum pressure applied on the urethra. Ergonomics is aimed to be improved as well.