Monitoring of the muscle effort in wheelchair users using FBG based sensors

The World Health Organization estimated that 65 million people need a wheelchair in their daily lives. In this work, a fiber Bragg gratings (FBGs) based sensing system was developed for muscle effort monitoring in wheelchair users (WCUs). The architecture consisted of six sensors, each of it, is constituted by one FBG embedded in epoxy resin. The sensors were placed on the biceps, deltoids, and triceps (three sensors in each arm), and the sensing system was tested in four WCUs' volunteers that performed some of their daily exercises: movement in a horizontal plane using two different hand patterns (arched and semicircular movements - patterns A and B, respectively), vertical (VD) and inclined dips (ID). The muscle effort induces a deformation in the epoxy resin (strain/compression), which can be related to the FBGs' wavelength shift. According to the results, on the horizontal plane, the arched movement is associated to lower deformation amplitudes and, therefore, a reduced muscle effort - comparing with the semicircular displacement. Also, dips revealed to have the highest and most sudden muscle effort applied in the arms. The results obtained with the proposed sensing system provided deeper knowledge related to the muscle effort required by WCUs during their daily movements. Based on this information, they can adopt different postures, resulting in minor muscle fatigue, and consequently a better quality of life.