Analysis of Different Stimulus for Evoking the ErrP Potential in a MI-BMI for Starting the Gait with a Lower-Limb Exoskeleton

A new approach that includes the detection of Error Related Potentials (ErrP) for self-tuning wrong commands in MI-BMI, with the aim of improving the accuracy of a lower limb exoskeleton gait initiation system, is currently in its early stages of development. Due to the requirement of warning the subject before the command is executed, a different type of stimulus must be used to evoke the ErrP in cases where the exoskeleton is about to move against the subject's will. Therefore, it is essential to research a feedback type that better differentiates the ErrP from the correct cases, in order to achieve efficient performance of the BMI. As such, we have analyzed both Tactile (T) and VisuoTactile (VT) feedbacks to not only verify the realism of the designed protocol, but also to examine their effectiveness in eliciting ErrP.