Detection of Plantar Pressure Using an Optical Technique

An optical sensor based on a fiber Bragg grating (FBG) array is proposed to detect the foot plantar pressure in adults. The plantar pressure signals are detected by three FBGs, spliced in the same piece of single-mode fiber (SMF-28), placed on the platform for the dynamic monitoring of gait motion. The male subject suffering from gait disorder experienced a pressure of 0.35 kPa on the rearfoot and a pressure of 0.15 kPa on the lateral forefoot, exhibiting a large pressure imbalance. The proposed scheme based on FBGs sensors shows a pressure sensitivity of 1.466 pm/kPa with an R2 value of 0.998. This study has revealed the feasibility of the proposed system as a useful alternative to other plantar pressure sensing systems. The advantages offered by the reported technique include; high weight tolerance, robustness, and increased sensitivity compared to other approaches reported in the literature.