In the last few years, new technologies and new methods in engineering were introduced in medical world. Minimaly Invasive Surgery recently became a key field of synergy accross many areas of engineering. Usage of endoscopic tools and cameras in conjunction with were imaging technics set up a complete working environment in the operating theatre. The work of this paper mainly focus on the design of a new surgical tool for colonoscopy. This new robotic structure improves conditions for the procedure of colonoscopy. This is in order to reduce the injuries due to contacts with the intestinal wall during the operation. It is proposed to redesign the distal segment of the colonoscope with the aim of limiting its contact with the intestine. The automation of this new actuator lies in its capacity to sense and control its distance to the intestinal wall. The design of a specific actuator EDORA (Distale Extremity with Automatique ORientation) is performed, using three metal bellows (three deformable chambers) and an electro-pneumatic actuation. This first tool was built to verify the feasability of the design. Experimental results show that its reactions were in accordance with the specifications made by the sugeons. The feasibility model indicated that the actuator reacts in a differential relationship to its transverse movements. Thanks to an uncoupled study from the pneumatic-mechanic system, a matched model is presented. It is validated and consolidated by experimental tests. To increase the perfomances of the new tip of colonoscope, the EDORA-01 is equipped with 3 optical sensors without contact which make possible to estimate the position of the head of the coloscope in relation to the wall. The three informations obtained control the pressures in the three rooms of the EDORA-01. These controls make possible to maintain the head of the coloscope in the centre of a tube representing the colon. The control efficiency being proven, it could be applied on to a new prototype. This new prototype, made in silicone, can bend up to 160°. For the moment, the distance sensors are not integrated to the tool, but in a future version, experimental tests will be made in vitro.