Design and Analysis of a Stand-aided Lower-Limb Exoskeleton System for Pediatric Rehabilitation

The effective movement of lower-body joints imparts a crucial role while performing the daily living activities (ADL). However, these movements become constrained in case of neuromuscular disorders due to the feeble muscles and damaged nerves. Moreover, in view of pediatric population, the limited mobility of lower-limb joints is majorly due to the post-stroke gait pathologies. In this work, the design, analysis, and prototyping of a novel 6-DOFs lower-limb exoskeleton system (LLES v2) is proposed for the pathological gait rehabilitation of pediatric subjects (8-12 years, 25-40 kg, 130±2cm). Primarily, the CAD of the stand-held system is proposed in SolidWorks software with required design features. Assigning the material as Aluminum alloy and Steel, finite element analysis (FEA) of the wheel-supported stand assembly is carried out for two different loading conditions, i.e., reaction period and single support phase in a gait cycle. Thereafter, the FEA of foot pad is carried out for maximum loading conditions with two different grades of Steel material. From the simulation results of stress and deformation, the most reliable material is selected for the safe design of the stand assembly and foot fad. Finally, invoking the design parameters and selected materials, the working prototype of the exoskeleton system is briefly presented.