Flexible endoscopes have been recently used for new surgical procedures called NOTES, i.e. Natural Orifice Transluminal Endoscopic Surgery. However, the movements of conventional flexible endoscopes are limited and surgeons can only perform basic tasks with these systems. In order to enhance endoscopes possibilities and workspace, several solutions have been proposed to redesign the whole endoscopic system. New devices have been proposed recently which are made up of a classical endoscope basis with two additional arms. However, these mechanical devices are not completely adequate to properly perform NOTES. That is why we are currently developing a robotized system which can be simultaneously teleoperated while performing autonomous motions. This article presents the constraints of transluminal surgery, existing devices and our new system together with its mathematical modeling.