Feasibility of a Wearable Soft Robot Triggered by Brain-Computer Interface for Stroke Upper Extremity Rehabilitation

Conventional robot designs have been applied as feedback stages in brain-computer interfaces (BCI) for stroke upper limb neurorehabilitation, showing promising results. Soft -robotic devices can be simpler and less expensive to manufacture, and provide ergonomic advantages over traditional designs, allowing to increase the efficacy and availableness of BCI systems for stroke neurorehabilitation. However, patients' degrees of control, neurophysiological activity, and system's usability with a BCI, using a soft robotic device as feedback, have not been assessed in stroke. For these reasons, a BCI system with a soft robotic feedback device was assessed in stroke patients. Fifty trials were acquired to setup the system, and another fifty trials were performed for evaluating patients' BCI control and cortical activity during movement intention (MI) and robotic feedback. User experience with the BCI was also assessed. Classification accuracy was in the range of 71.3% to 97.5%. Significant decrease in alpha power was observed during both motor intention and robotic feedback, but significant decrease in beta power was only observed during motor intention. BCI performance was high and in the range of reported BCI stroke interventions that used traditional robotics as feedback. Power decrease observed predominantly in alpha during soft robotic feedback was likely due to the eliciting of motor-related mechanisms. Quantification of user experience with the BCI implied that the system complexity is adequate for stroke patients. Therefore, a BCI system aimed at stroke neurorehabilitation can incorporate a soft robotic design as feedback and has potential for upper extremity interventions.