Abstract: A novel slim FBG (Fiber Bragg grating) sensor device and its application in the real-time dynamic shape detection of colonoscope are presented. The sensing network device comprises a plurality of FBG sensors mounted on the body of a slim flexible wire. After the colonoscope is advanced in the body，the wire is pushed through the biopsy channel of the colonoscope. It bends with the curvature of the colonoscope. The FBG sensors capture deformation of the sensor wire，and reconstruct the shape of colonoscope. Experiments in the colon of a live swine have been done. Configuration of experimental system and experimental result are also given.

Key words: Colonoscope, FBG, Sensor net, Spatial shape