This paper presents perception assistance with an active camera for an upper-limb power-assist exoskeleton that assists user perception as well as user motion when the user interacts with the environment using sensors of the exoskeleton. The active stereo camera monitors user interaction with the environment, so the exoskeleton identifies objects that can be touched or grabbed by the user. Stereo camera positioning is controlled to continuously track the exoske-leton end-effector, ensuring that the user’s hand always lies within the camera viewfield. If any obstacle might block the camera viewfield, the camera is controlled to avoid the obstacle. The effectiveness of the proposed concept is evaluated in experiments.

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This article presents how an adapted design of a mechatronics system and its control can lead to an intuitive interface for patients performing sit-to-stand motions. We focus on the design of a control based on fuzzy rules obtained by an analysis of external interaction forces subjects during motion. Experiments are done with 10 diseased patients in Bellan hospital and show a good learning rate.

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This paper presents the design, analysis, and a clinical application of a reconfigurable, parallel mechanism based, force feedback exoskeleton for the human ankle. The device can either be employed as a balance/proprioception trainer or configured to accommodate range of motion (RoM)/strengthening exercises. The exoskeleton can be utilized as a clinical measurement tool to estimate dynamic parameters of the ankle and to assess ankle joint properties in physiological and pathological conditions. Kinematic analysis and control of the device are detailed and a protocol for utilization of the exoskeleton to determine ankle impedance is discussed. The prototype of the device is also presented.

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The ability to walk is important for independent living and when this capacity is affected by neurological injury, gait therapy is the traditional approach to re-train the nervous system. The importance of this problem is illustrated by the approximately 5.8 million stroke survivors alive in the US today and an estimated additional 700,000 strokes occurring each year, many requiring gait therapy. This manuscript presents the design and proof-of-concept testing for a novel device to deliver gait therapy. While robotic devices to train gait therapy exist, none of them take advantage of the concept of passive walkers and most of them impose the kinematics of unimpaired gait on impaired walkers. Yet research has found that proper neural input and stimulation is a critical factor for an efficacious therapy program. This novel device might afford a more ecological gait therapy including heel-strike.

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Studies have shown locomotor adaptation of the ankle to assistive torques, but the ability of the knee to adapt to assistive forces has not yet been explored. Understanding how humans modulate knee joint kinematics during gait could be valuable for designing assistive devices for stroke patients. In this study we examined how healthy subjects adapt to knee flexion torque assistance during gait. We hypothesized that 1) when given assistance subjects would adapt their locomotor patterns to walk with kinematics similar to baseline values and 2) removal of assistance following adaptation would result in substantially reduced knee flexion. Contrary to expectations, data from the five subjects show a weak adaptation and an increase in knee flexion kinematics after forces were removed. These results suggest that neuromuscular control of the knee joint during walking is not strongly modulated by feedforward mechanisms.

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