In this pioneering study, we unveiled a groundbreaking approach for actuating rehabilitation robots through the innovative use of magnetic technology as a seamless haptic force generator, offering a leap forward in enhancing user interface and experience, particularly in end-effector-based robots for upper-limb extremity motor rehabilitation. We employed the Extended Kalman Filter to meticulously analyze and formalize the robotic system's nonlinear dynamics, showcasing the potential of this sophisticated algorithm in accurately tracking and compensating for disturbances, thereby ensuring seamless and effective motor training. The proposed planar robotic system embedded with magnetic technology was evaluated with the recruitment of human subjects. We reached a minimum RMS value of 0.2 and a maximum of 2.06 in our estimations, indicating our algorithm's capability for tracking the system behavior. Overall, the results showed significant improvement in smoothness, comfort, and safety during execution and motor training. The proposed novel magnetic actuation and advanced algorithmic control opens new horizons for the development of more efficient and user-friendly rehabilitation technologies.
There have been different reports of developing Brain-Computer Interface (BCI) platforms to investigate the noninvasive electroencephalography (EEG) signals associated with plan-to-grasp tasks in humans. However, these reports were unable to clearly show evidence of emerging neural activity from the planning (observation) phase - dominated by the vision cortices - to grasp execution - dominated by the motor cortices. In this study, we developed a novel vision-based grasping BCI platform that distinguishes different grip types (power and precision) through the phases of plan-to-grasp tasks using EEG signals. Using our platform and extracting features from Filter Bank Common Spatial Patterns (FBCSP), we show that frequency-band specific EEG contains discriminative spatial patterns present in both the observation and movement phases. Support Vector Machine (SVM) classification (power vs precision) yielded high accuracy percentages of 74% and 68% for the observation and movement phases in the alpha band, respectively.
The bispectrum stands out as a revolutionary tool in frequency domain analysis, leaping the usual power spectrum by capturing crucial phase information between frequency components. In our innovative study, we have utilized the bispectrum to analyze and decode complex grasping movements, gathering EEG data from five human subjects. We put this data through its paces with three classifiers, focusing on both magnitude and phase-related features. The results highlight the bispectrum's incredible ability to delve into neural activity and differentiate between various grasping motions with the Support Vector Machine (SVM) classifier emerging as a standout performer. In binary classification, it achieved a remarkable 97\% accuracy in identifying power grasp, and in the more complex multiclass tasks, it maintained an impressive 94.93\% accuracy. This finding not only underscores the bispectrum's analytical strength but also showcases the SVM's exceptional capability in classification, opening new doors in our understanding of movement and neural dynamics.