Event-related changes detection in sensorimotor rhythm

Abstract

Brain activities initiate motion in the human body. In our research we try to detect brain electrical activities and generate control signals for robotic devices like prosthetic legs. Human legs are associated with a small representation area in the sensorimotor (SMR) cortex, which is located deep inside the inter hemispheric fissure. It is difficult to observe any electroencephalographic activity related to the legs. Detection of sensorimotor signals, based on leg imagery, could potentially be useful in medical applications, i.e. for systems that are using brain-computer interface for lower limbs assistance. We investigate reactivity of sensorimotor rhythm i.e., murhythm, as a result of given tasks, such as, motor execution (ME) and motor imagery (MI) of the leg. Resulting SMR was analyzed, for each task state and evaluated in terms of event-related de synchronization and event-related synchronization patterns. Higher power concentration was observed in the foot representation and peripheral areas, during both ME and MI tasks. No contralateral dominance was detected during left or right discrimination tasks. Results provide a foundation for leg imagery based, interfacing and control signals creation. This could be used for locomotion functions’ restoration in a lower limb wearable rehabilitation system. Spinal cord injury patients could, also, be potential users of this type of biomechanical systems.