Abstract
Optical Backscattering Reflectometry (OBR) can be used for one-dimensional distributed strain sensing of medical needles. To achieve 3D shape sensing the needle should be equipped with multiple optical fibers. A feasible configuration can be done using two pairs of parallel optical fibers, which will measure the strain in two directions perpendicular to a needle axis. However, OBR is limited to a single fiber sensing because of its inability to discriminate scattering patterns of different fibers. To achieve multiplexing, it is proposed to use nanoparticle doped fibers (NP-doped) with high scattering power and splice them to standard single-mode (SMF) pigtails with different lengths. As a result of such configuration, the NP-doped fibers, which are used as sensing fibers, are spatially separated by standard fibers.