mano: A Wearable Hand Exoskeleton for Activities of Daily Living and Neurorehabilitation

Abstract

Abstract-Hand sensorimotor impairments are among the most common consequences of injuries affecting the central and peripheral nervous systems, leading to a drastic reduction in the quality of life for affected individuals. Combining wearable robotic exoskeletons and human-machine interfaces is a promising avenue for the restoration and substitution of lost and impaired functions for these users. In this study, we present a novel hand exoskeleton, mano, designed to assist and restore hand functions of people with motor disabilities during activities of daily living (ADL) and in neurorehabilitative scenarios. Compared to state-of-the-art devices, our system is fully wearable, portable and minimally obtrusive on the hand. The exoskeleton can actively control flexion and extension of all fingers, while allowing natural somatosensorial interactions with the environment surrounding the users. We evaluated the device from four different perspectives. A mechanical characterization, showing that the exoskeleton can cover more than 70% of healthy hand workspace and it can achieve forces at the fingertips sufficient for ADL. A functional characterization, where we showed how two users who suffered from spinal cord injuries were able to perform several ADL for the first time since their accidents. Thirdly, we evaluated the system from a neuroimaging perspective, showing that the device can elicit EEG brain patterns typical of natural hand motions. We finally exemplified the control of the hand exoskeleton within an exemplar framework, a brain-machine interface scenario, showing how motor intention can be successfully decoded for a continuous control of the device. Overall, our results showed that the device represents an ecological solution for use both in ADL and in scenarios aimed at promoting sensorimotor recovery.

Brain-actuated functional electrical stimulation elicits lasting arm motor recovery after stroke

“…A third limitation, although not critical, concerns the limited accuracy and repeatability of hand movements generated by FES. A hand orthosis provides more controlled kinematics 62 and, thus, it would be interesting to explore the combination of hand orthosis and FES so as to evaluate whether a BCI that operates both together yields larger motor improvements.…”

Sensory threshold neuromuscular electrical stimulation fosters motor imagery performance

“…Following this theory, with St-NMES guidance the descending and ascending motor pathways are both activated below the motor threshold, which might correspond to the physiological activation of the peripheral pathway during MI. As explained in [34] have shown that a robotic orthosis is more suitable than visual feedback to train motor imagery networks, whereas a passive movement of the joint will induce similar activation of motor networks [26,35] -but see [69] for a possible solution.…”

“…Already several studies have implemented a somatosensory feedback to improve the discriminability of MI brain patterns. For instance, some authors used a robotic orthosis in order to induce a passive movement of the joint [25,26,27], a neuromuscular electrical stimulation (NMES) to induce muscular contraction [28,29,30] or a vibrotactile stimulation that provides tactile afferences of the targeted limb [20,31,32,33]. The major conclusion of these experiments is that somatosensory feedback is more appropriate to enhance MI brain patterns.…”

A HERO for Stroke Patients: a new hand exoskeleton 3D printed on textiles for rehabilitation

“…According to these studies, the specified torque is enough to apply HERO in ADLs and in clinical procedures with spastic stroke patients. This criterion was higher than those generally adopted in exoskeleton projects [34,35]. However, thorough analyzes still need to be done to assess the real force applied to the fingertips and to overcome spasticity in stroke patients.…”