Digestive endoscopy (examination of the digestive tract through the mouth) has developed considerably over the last 40 years, allowing the physicians to perform more and more complex operations. To allow the development of therapeutic possibilities, endoscopic systems are constantly evolving ont the mechanical and imagery sides but it remains to solve the need to transmit, as closely as possible, the forces of interaction between tools and tissues. Hance, there is a need to develop a force sensor to provide the gastroenterologist with information relating to the force applied to the tissues, that is not tainted by parasitic forces. These force sensors allow not only to obtain information on the resistance of walls without friction related interference in the working channels of endoscopes but also to get an "augmented reality" on the tissue resistance. The gastroenterologist will then feel these forces as amplified and be able to handle these therapeutic tools more precisely. The potential medical applications in gastroenterology are numerous at both diagnostic and therapeutic levels. The application targeted in this project is to detect if a suture is transmural (through the entire tissue). This is intended to help treating morbid obesity with endoluminal restrictive (by decreasing the volume of the stomach) surgery (via the mouth).