LOPES aims for an active role of the patient by selective and partial support of gait functions during robotic treadmill training sessions. Virtual model control (VMC) was applied to the robot as an intuitive method for translating current treadmill gait rehabilitation therapy programs into robotic rehabilitation therapy. Virtual models are proposed for the selective control of gait functions during treadmill training. From this collection of models several, representing the extremes of the entire set of virtual models, were implemented. The results show that VMC is a promising method for the control of a gait rehabilitation robot.

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A new experimental platform permits us to study a novel variety of issues of human motor control, particularly full 3-D movements involving the major seven degrees-of-freedom (DOF) of the human arm. We incorporate a seven DOF robot exoskeleton, and can minimize weight and inertia through gravity, Coriolis, and inertia compensation, such that subjects’ arm movements are largely unaffected by the manipulandum. Torque perturbations can be individually applied to any or all seven joints of the human arm, thus creating novel dynamic environments, or force fields, for subjects to respond and adapt to. Our first study investigates a joint space force field where the shoulder velocity drives a disturbing force in the elbow joint. Results demonstrate that subjects learn to compensate for the force field within about 100 trials, and from the strong presence of aftereffects when removing the field in some randomized catch trials, that an inverse dynamics, or internal model, of the force field is formed by the nervous system. Interestingly, while post-learning hand trajectories return to baseline, joint space trajectories remained changed in response to the field, indicating that besides learning a model of the force field, the nervous system also chose to exploit the space to minimize the effects of the force field on the realization of the endpoint trajectory plan. Further applications for our apparatus include studies in motor system redundancy resolution and inverse kinematics, as well as rehabilitation.

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The stand-alone wearable power assist suit we develo-ped gives caregivers the extra strength they need to lift patients while avoiding back injuries. To put this suit to practical use, we improved sensing system and the mechanisms. To stabilize muscle tenseness sensing more, we developed an all-in-one sensor that built the sensor into a mesh belt and improved sen-sing characteristics. We expanded the movable range and function of the suit. We increased actuator output torque by increasing the number of cuffs inserted into actuators. Based on equations derived from static body mechanics using joint angles, joints torques required to maintain a position are calculated by an embedded microcomputer and required joint torques was combined with muscle sensor output signals to gene-rate control signals. We developed an exoskeleton for measurement having the same frame and potentiometers as the suit and measured muscle force by having a user wear the exoskeleton, and proved that each unit of the suit transmitted assistance torque directly to each joint. We also found that a user wearing the suit could lift weight using half or less muscle power, i.e., muscle power doubled.

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Exoskeletons for human performance augmentation are controlled and wearable devices and machines that can increase the speed, strength, and endurance of the operator. So far most researchers focus on the upper limb exoskeletons. To help those who need to travel long distances by feet with heavy loads such as infantry soldiers, this paper presents a control principle of a lower extremity exoskeleton. An exoskeleton foot is designed to measure the human and the exoskeleton’s ZMP. Using the measured human ZMP as the reference, the exoskeleton’s ZMP is modified by torso control and ground reaction force control so that theexoskeleton can walk stably. Test prototypes, initial experiment results, and preliminary dynamic analysis are also presented.

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Different types of neurological injuries affect the patient walking ability. Rehabilitation Engineering provides equipment and devices to aid these patients to recover the movements or to improve their quality of life. The aim of the present study was to develop an equipment to assist the lower limb movements when a physical deficiency is installed. It was designed an exoskeleton, which consists of a hip orthosis equipped with pneumatic artificial muscles. The orthosis was molded for a patient who had motor deficit resultant of Poliomielitis. The kinematics and dynamics of the hip and the lower limb was studied to determine the force produced by the artificial muscles in the initial and final positions of the patient’s lower limb during the gait. A control system for the pneumatic muscle using the remaining myoelectrics signal of the patient’s muscle was developed. This signal was obtained by two electrodes and modulated to make the pneumatic muscle control. The exoskeleton reported here has proved to be able of assisting the hip flexion movement

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