This flexure information deriving apparatus (10) derives flexure information representing the size and direction of bending of a detection-target part group (410) provided on an optical guiding member (420). The detection-target part group has multiple detection-target parts disposed at the same position along the length of the optical guiding member. Each of the detection-target parts modulates, in accordance with the size and direction of bending, the intensity of light optically guided by the optical guiding member. The flexure information deriving apparatus is provided with an input unit (190) to which detected-light-volume information of light having wavelengths corresponding to the respective detection-target parts is inputted a storage unit (130) that stores a flexure coefficient and intensity modulation information of each of the detection-target parts, and light volume information relationship that represents the relationship among the detected-light-volume information, and the flexure coefficient and the intensity modulation information a first calculation unit (212) that calculates light volume change information for each of the detection-target parts on the basis of the light volume information and the intensity modulation information and a second calculation unit (214) that calculates the flexure information of the detection-target part group on the basis of the flexure coefficient and the light volume change information.Lappareil de déduction dinformations de flexion (10) de linvention déduit des informations de flexion représentant la taille et la direction de courbure dun groupe de modules de détection-ciblage (410) équipant un élément de guidage optique (420). Le groupe de modules de détection-ciblage comprend plusieurs modules de détection-ciblage disposés à la même position le long de lélément de guidage optique. Chaque module de détection-ciblage module, en fonction de la taille et de la direction de courbure, lintensité de la lumière guidée opti
