Variable Stiffness Actuators for Wearable Applications in Gait Rehabilitation

Abstract

Variable stiffness actuators (VSAs) have emerged as a promising actuation principle for devices focused on physical interaction. Specifically, characteristics such as shock load absorbing, passive backdrivability, and variable device performance motivate the use of VSA in a rehabilitation context. Multiple studies have exhibited the advantages of applying VSA in gait assistance, improving the human–robot interaction, and preserving the device in complex interaction applications. This chapter presents an overview of VSAs and their potential applications in gait rehabilitation. The first part explains the VSA concepts, several configurations to accomplish this behavior, and some devices based on this principle. The second part shows the portable and wearable T-FLEX ankle exoskeleton, focusing on its mechanical and electronic design. Lastly, this chapter presents two experimental validations with healthy subjects in gait assistance and stationary therapy scenarios.