Resolving twist-induced errors in fiber optic shape sensing via polarization-sensitive reflectometry

We present a new technique for removing twist-induced distortions in fiber optic shape sensing. In the method, a standard swept-wavelength reflectometer is used to perform polarimetric measurements, which allows the extraction of the strain necessary for shape reconstruction and the twist evolution along the fiber. By applying a model capable of synthesizing these two parameters, we demonstrate a significant improvement in 3D-shape reconstruction, achieving an accuracy of 3.6 mm/m in reconstructing a helical shape, even in the presence of uncontrolled twist.