A new robotic exoskeleton for the upper-limb has been designed and constructed. Its primary purpose is to act as a proof-of-concept prototype for a more sophisticated rehabilitation and assessment device that is currently in development. Simultaneously, it is intended to extend the capabilities of an existing planar exoskeleton device. The robot operates in the horizontal plane and provides independent control of a user’s shoulder, elbow and wrist joints using a cable-driven actuation system. The novel component of the design is a curved track and carriage which allows the mechanism that drives the shoulder joint to be located away from the user, underneath their arm. This paper describes the design of the robot, and provides an initial indication of its performance.

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Brain-computer interface (BCI) research deals with establishing commu-nication pathways between the brain and external devices. BCI systems can be broadly classified depending on the placement of the electrodes used to detect and measure neurons firing in the brain: in invasive systems, electrodes are inserted directly into the cortex; in noninvasive systems, they are placed on the scalp and use electroencephalography or electrocorticography to detect neuron activity. This WTEC study was designed to gather information on worldwide status and trends in BCI research and to disseminate it to government decisionmakers and the research community. The study reviewed and assessed the state of the art in sensor technology, the bioticabiotic interface and biocompatibility, data analysis and modeling, hard-ware implementation, systems engineering, functional electrical stimulation, noninvasive communication systems, and cognitive and emotional neuroprostheses in academic research and industry. The WTEC panel identified several major trends in current and evolving BCI research in North America, Europe, and Asia. First, BCI research throughout the world is extensive, with the magnitude of that research clearly on the rise. Second, BCI research is rapidly approaching a level of first-generation medical practice; moreover, BCI research is expected to rapidly accelerate in nonmedical arenas of commerce as well, particularly in the gaming, automotive, and robotics industries. Third, the focus of BCI research throughout the world is decidedly uneven, with invasive BCIs almost exclusively centered in North America, noninvasive BCI systems evolving primarily from European and Asian efforts, and the integration of BCIs and robotics systems championed by Asian research programs. In terms of funding, BCI and brain-controlled robotics programs have been a hallmark of recent European research and technological development. The range and investment levels of multidisciplinary, multinational, multilaboratory programs in Europe appear to far exceed that of most university and government-funded BCI programs in the United States and Canada. Although several U.S. government programs are advancing neural prostheses and BCIs, private sources have yet to make a major impact on BCI research in North America generally. However, the U.S. Small Business Innovative Re-search grants (SBIRs) and Small Technology Transfer Research grants (STTRs) have been effective in promoting transition from basic research to precommercialized prototypes. In Asia, China is investing hea-vily in biological sciences and engineering in general, and the extent of investment in BCI and BCI-related research has grown particularly rapidly; still, the panel observed little coordination between various programs. Japanese universities, research institutes, and laboratories also are increasing their investment in BCI research. Japan is especially vigorous in pursuing nonmedical applications and exploiting its expertise in BCI-controlled robotics. The WTEC panel concludes that there are abundant and fertile opportunities for worldwide collaborations in BCI research and allied fields.

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Locomotor training using body weight support on a treadmill and manual assistance is a promising rehabilitation technique following neurological injuries, such as spinal cord injury (SCI) and stroke. Previous robots that automate this technique impose constraints on naturalistic walking due to their kinematic structure, and are typically operated in a stiff mode, limiting the ability of the patient or human trainer to influence the stepping pattern.We developed a pneumatic gait training robot that allows for a full range of natural motion of the legs and pelvis during treadmill walking, and provides compliant assistance. However, we observed an unexpected consequence of the device’s compliance: unimpaired and SCI individuals invariably began walking out-ofphase with the device. Thus, the robot perturbed rather than assisted stepping. To address this problem, we developed a novel algorithm that synchronizes the device in real-time to the actual motion of the individual by sensing the state error and adjusting the replay timing to reduce this error. This paper describes data from experiments with indi-viduals with SCI that demonstrate the effectiveness of the synchronization algorithm, and the potential of the device for relieving the trainers of strenuous work while maintaining naturalistic stepping.

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The present invention relates to an exoskeleton interface apparatus that parallels human arm motion and is comprised of a serial assemblage of five powered linkages and joints based at a rigid support structure worn on the torso of the human subject. Such apparatus generates shoulder rotation using three orthogonal revolute joints mounted on serial linkages encompassing and intersecting at the anatomical glenohumeral joint. Elevation of the shoulder joint is articulated using a link member driven by a single revolute joint mounted in the torso structure. Passive adjustable linkages are used to match variation in anatomical forearm length, upper arm length, and scapula-to-glenohumeral radius. A plurality of integrated dc motor/harmonic drive transmission modules is co-located on adjoining linkages to power the joints. Force is exchanged with the human at the handgrip and elbow brace, and reacted to the torso structure via the base attachment. The present invention is applicable in particular to rehabilitation of the shoulder.

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The visual grasp reflex provides automatic orienting of gaze (the visu-al axis in space) to novel visual stimuli. Previous studies have demonstrated activation of neck muscles of awake monkeys appearing at a short fixed latency (55 to 95 ms) after visual target presentation, regard-less of whether or when saccades are made. The purpose of these early visually-driven muscle activations may be to prime head rotation required as a part of the coordinated eye-head movement to the target. Simi-lar orienting responses might be found for visually guided reaching. Here, we explore early visually-dri-ven muscle activations of the human upper limb immediately preceding planar reaching movements. Subjects performed reaches towards small visual peripheral targets while upper limb kinematics were recorded and intramuscular electromyography was collected from four shoulder and elbow muscles. Subjects maintained their right hand at a central fixation marker that was extinguished for a gap period (200 ms) prior to appearance of a peripheral target. Subjects were instructed to reach to the target as quickly as possible. Some subjects exhibited a short burst of muscle activity (about 20 ms duration) time-locked to visual target onset. This burst occurred around 85 ms to 105 ms after target onset and preceded the onset of muscle activity associated with volitional arm motion by about 100 ms. Notably, this burst was dependent on target location: visually-driven muscle activity occurred in right shoulder extensor muscles for rightward targets and was absent for leftward targets. In order to better dissociate the visual burst from volitional motor activity, we employed a delay paradigm. No time-locked muscle activity was present in the delay task either after the target appeared or after the fixation marker was extinguished. This suggests that the visual burst is dependent on the imminence of voluntary movement and the laterality of the tar-get. We conclude that the appearance of a visual target can result in short-latency activity on the arm musculature that is appropriate for orienting the arm to the target.

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