Sequence-based manipulation of robotic arm control in brain machine interface

In brain machine interfaces (BMI), the brain activities are recorded by invasive or noninvasive approaches and translated into command signals to control external prosthetic devices such as a computer cursor, a wheelchair, or a robotic arm. Although many studies confirmed the capability of BMI systems in controlling multi degrees-of-freedom (DOF) prosthetic devices using invasive approaches, BMI research using noninvasive paradigms is still in its infancy. In this paper, a new robotic BMI platform has been developed using electroencephalography (EEG) technology to control a 6-DOF robotic arm. EEG signals were collected from the scalp using a wireless headset exploiting a new fast-training paradigm named as “imagined body kinematics”. A regression model was employed to decode the kinematic parameters from the EEG signals. The subjects were instructed to voluntarily control a virtual cursor in multiple trials to hit different pre-programmed targets on a screen in an optimized sequence. The command signals generated from hitting the targets during trials were applied to control sequential movements of the robotic arm in a discrete manner to manipulate an object in a two-dimensional workspace. This approach is derived from a basic shared control strategy where the robotic arm is responsible for carrying out complex maneuvers based on the user’s intention. Our proposed BMI platform yielded a high success rate of 70% in a sequence-based manipulation task after only a short time of training (10 min). The developed platform serves as a proof-of-concept for EEG-based neuro-prosthetic devices.