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A noninvasive, hybrid brain/neural hand exoskeleton restored intuitive control of grasping motion, restoring independent activities to quadriplegics.

The evolution to bipedalism forced humans to develop suitable strategies for dynamically controlling their balance, ensuring stability, and preventing falling. The natural aging process and traumatic events such as lower-limb loss can alter the human ability to control stability significantly increasing the risk of fall and reducing the overall autonomy. Accordingly, there is an urgent need, from both end-users and society, for novel solutions that can counteract the lack of balance, thus preventing falls among older and fragile citizens. In this study, we show a novel ecological approach relying on a wearable robotic device (the Active Pelvis Orthosis, APO) aimed at facilitating balance recovery after unexpected slippages. Specifically, if the APO detects signs of balance loss, then it supplies counteracting torques at the hips to assist balance recovery. Experimental tests conducted on eight elderly persons and two transfemoral amputees revealed that stability against falls improved due to the “assisting when needed” behavior of the APO. Interestingly, our approach required a very limited personalization for each subject, and this makes it promising for real-life applications. Our findings demonstrate the potential of closed-loop controlled wearable robots to assist elderly and disabled subjects and to improve their quality of life.

In recent years, the robotic research area has become extremely prolific in terms of wearable active exoskeletons for human body motion assistance, with the presentation of many novel devices, for upper limbs, lower limbs, and the hand. The hand shows a complex morphology, a high intersubject variability, and offers limited space for physical interaction with a robot: as a result, hand exoskeletons usually are heavy, cumbersome, and poorly usable. This paper introduces a novel device designed on the basis of human kinematic compatibility, wearability, and portability criteria. This hand exoskeleton, briefly HX, embeds several features as underactuated joints, passive degrees of freedom ensuring adaptability and compliance toward the hand anthropometric variability, and an ad hoc design of self-alignment mechanisms to absorb human/robot joint axes misplacement, and proposes a novel mechanism for the thumb opposition. The HX kinematic design and actuation are discussed together with theoretical and experimental data validating its adaptability performances. Results suggest that HX matches the self-alignment design goal and is then suited for close human-robot interaction.

BackgroundDespite evidence from neuroimaging research, diagnosis and early prognosis in the vegetative (VS/UWS) and minimally conscious (MCS) states still depend on the observation of clinical signs of responsiveness. Multiple testing has documented a systematic variability during the day in the incidence of established signs of responsiveness. Spontaneous fluctuations of the Coma Recovery Scale-revised (CRS-r) scores are conceivable.MethodsWe retrospectively analyzed the CRS-r repeatedly administered to 7 VS/UWS and 12 MCS subjects undergoing systematic observation during a conventional 13 weeks. rehabilitation plan.ResultsThe CRS-r global, visual and auditory scores were found higher in the morning than at the afternoon administration in both VS/UWS and MCS subgroups over the entire period of observation. The probability for a VS/UWS subject of being classified as MCS at the morning testing at least once during the 13 weeks. observation was as high as 30 %, i.e., compatible with the reported misdiagnosis rate between the two clinical conditions.ConclusionsMultiple CRS-r testing is advisable to minimize the risk of misclassification; estimates of spontaneous variability could be used to characterize with greater accuracy patients with disorder of consciousness and possibly help optimize the rehabilitation plan.

BackgroundBrain-machine interfaces (BMIs) allow direct translation of electric, magnetic or metabolic brain signals into control commands of external devices such as robots, prostheses or exoskeletons. However, non-stationarity of brain signals and susceptibility to biological or environmental artifacts impede reliable control and safety of BMIs, particularly in daily life environments. Here we introduce and tested a novel hybrid brain-neural computer interaction (BNCI) system fusing electroencephalography (EEG) and electrooculography (EOG) to enhance reliability and safety of continuous hand exoskeleton-driven grasping motions.Findings12 healthy volunteers (8 male, mean age 28.1 ± 3.63y) used EEG (condition #1) and hybrid EEG/EOG (condition #2) signals to control a hand exoskeleton. Motor imagery-related brain activity was translated into exoskeleton-driven hand closing motions. Unintended motions could be interrupted by eye movement-related EOG signals. In order to evaluate BNCI control and safety, participants were instructed to follow a visual cue indicating either to move or not to move the hand exoskeleton in a random order. Movements exceeding 25% of a full grasping motion when the device was not supposed to be moved were defined as safety violation. While participants reached comparable control under both conditions, safety was frequently violated under condition #1 (EEG), but not under condition #2 (EEG/EOG).ConclusionEEG/EOG biosignal fusion can substantially enhance safety of assistive BNCI systems improving their applicability in daily life environments.Electronic supplementary materialThe online version of this article (doi:10.1186/1743-0003-11-165) contains supplementary material, which is available to authorized users.

Visual pursuit marks substantial recuperation from a vegetative state and evolution into a minimally-conscious state, but its incidence in different studies suggests some unreliability in contrast with its established prognostic relevance. Subjects in vegetative (n=9) or minimally-conscious (n=13) states were tested for visual pursuit 6 times/day (9:30, 10:30, and 11:30 am, and 2:00, 3:00, and 4.00 pm, for a total of 132 determinations). Visual pursuit was observed at all testing times in 8 minimally-conscious patients, and never in 5 subjects in a vegetative state. Its incidence per subject ranged from 50-100% of testing times in the minimally-conscious state (83±23%), and 0-33% in a vegetative state (7%±12), with spontaneous fluctuations during the day and maximal levels at 10.30 am and 3.00 pm, and was never observed at the post-prandial time point (2:00 pm). The overall chance of observing visual tracking at least once during the day was ∼33% in the vegetative state, whereas that of not observing it in the minimally-conscious state was ∼38%. These percentages are congruent with the reported misdiagnosis rate between the two conditions, and document spontaneous variability possibly related to circadian rhythms.

We present the kinematic design and actuation mechanics of a wearable exoskeleton for hand rehabilitation of post-stroke. Our design method is focused on achieving maximum safety, comfort and reliability in the interaction, and allowing different users to wear the device with no manual regulations. In particular, we propose a kinematic and actuation solution for the index finger flexion/extension, which leaves full movement freedom on the abduction-adduction plane. This paper presents a detailed kineto-static analysis of the system and a first prototype of the device.