Proof-of-concept of a carpet-embedded heterogeneous optical fiber sensor system for gait analysis

This paper presents an optical fiber embedded intelligent carpet for gait analysis, where the system is able of measuring the ground reaction force and the foot position on the carpet (which can be used on the gait spatiotemporal parameters assessment). The system comprises of fiber Bragg gratings (FBGs) inscribed in silica fibers to detect the foot positioning and intensity variation-based sensors on polymer optical fibers (POFs) to estimate the ground reaction forces. The proposed system was characterized as function of foot impact positioning as well as applied forces and a high correlation between the sensors responses and the applied parameters was obtained on each case. Then, a proof-of-concept test was performed, where a volunteer placed his foot in different positions on the carpet, which show the feasibility of the system in the proposed application.