Patent ID: 6868195

Claim:
A device for detecting three-dimensional shapes of an elongated flexible body, comprising: a sensor cable adapted to be inserted into an axial coextensive passage within an elongated flexible body, said sensor cable having two pairs of fiber Bragg grating strands each having a plural number of refractive index change portions periodically in a predetermined pitch; a light source connectible to each one of said fiber Bragg grating strands to input a light beam containing a Bragg wavelength to said refractive index change portions; and a signal processor adapted to receive reflection diffraction light signals from said refractive index change portions of each fiber Bragg grating strand, and to detect a three-dimensional shape of said elongated flexible body by measuring degree of straining at each one of said refractive index change portions by way of comparison of said reflection diffraction light signals with a reference wavelength.