Abstract
Stroke-induced hand motor dysfunction severely limits activities of daily living (ADL), yet conventional rigid exoskeletons lack portability and fine motor control, while soft exoskeletons face challenges in sustained actuation accuracy. To address this problem, we developed a lightweight wire-driven hand exoskeleton system with 10 degrees-of-freedom (DoF), enabling independent metacarpophalangeal (MCP) to distal interphalangeal (DIP) joint control. The system employs a rigid-flexible coupling design with total wearable mass lower than 300 g and enhances anatomical compatibility across finger lengths (58-93mm). Motion commands are generated via a motor imagery-based brain-computer interface (MI-BCI) that decodes three grasp intensity levels (20%, 50%, and 80% maximum voluntary contraction) from 64-channel electroencephalogram (EEG), mapping to ADL-specific grasps (lateral grasp, precision grasp, and power grasp). The closed-loop control using the angle sensor compensates for the wire relaxation caused by long-term use. Validation with healthy subjects demonstrated 0° to 90° joint mobility to fulfill ADL requirements, and successful execution of 9 ADL tasks. This system establishes a portable, anatomically adaptive exoskeleton platform for stroke rehabilitation, using an MI-BCI as neural command input to trigger biomechanically precise assistance.
Authors
Jing, X., Chen, H., Li, Z., Inoue, Y., Zhou, G., Jimenez, T., Sanchez, J. C., Jiang, Y., Yokoi, H., Li, Y., & Yong, X.
http://dx.doi.org/10.2139/ssrn.5675826