Event-related changes detection in sensorimotor rhythm

Human walking gait is disrupted by the spinal cord injury (SCI) or amputation.1 Gait rehabilitation involves improvement of the motor control functions by the activation of neuro-plasticity. It can be achieved by deciphering and translation of brain signals that correspond to the execution, or action imagery, of the affected limb, into output commands. BCI could be used to build new communication channel between the brain and output devices. EEG features, generated against motor execution or imagery tasks, comprise of sensorimotor rhythms generated in the primary and sensory motor cortex. SMR are usually concentrated in the mu (8-11Hz) or beta (12-32Hz) frequency bands.2 SMR changes against each task are unique and can be exploited using feature extraction and classifications. This report highlights the changes in mu rhythm against the ME and MI of leg movement. The mu rhythm changes are quantified in terms of eventrelated desynchronization and event-related synchronization. ERD is associated with the proportional power decrease in concentration, while ERS with the proportional power increase in the signal. SMR ERD is linked with MI, as well as, with actual movement.3 Studies on tasks related to lower limbs are presented here.4,5 Investigations are required of SMR on leg tasks, both for ME and MI, to be used as control signals in BCI applications. The limbs somatotopy, in the sensory and motor cortices, enables cortical localization of ERD patterns. Lower limbs area representation is located deep within the interhemispheric fissure of the sensorimotor cortex, which makes it hard to detect ERD patterns.6 Materials and methods