The aim of this paper is to arbitrarily modify the load force of any selected muscle by using an exoskeleton, thus enabling «pinpointed» motion support, rehabilitation, and training. An advanced dynamic model, called a musculoskeletal-exoskeletal integrated human model, is developed. The driving-forces of the pneumatic actuators are designated by a muscle force control algorithm using the integrated model. A prototype power-assisting system is developed using pneumatic rubber actuators. The feasibility of the muscle force control is analyzed from a view point of nonlinear programming. The validity of the method is confirmed by measuring surface electromyographic signals of related muscles.

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In the design of exoskeletons for gait rehabilitation, the choice of degrees of freedom (DoFs) is one of the main issues. The goal of this research is to evaluate the effect of availability of additional DoFs related to balance-keeping on the normality of walking. These additional DoFs are the horizontal translations of the pelvis and the frontal rotation of the hip. Measurements on the gait of ten healthy subjects showed that kinematics and EMG differ only slightly when these DoFs are blocked (and only the sagittal joint rotations are available), in the impedance-controlled LOPES exoskeleton. This shows that omitting the additional DoFs allows walking with close-to-normal motor control, and also that effects of waking in this robot per se overshadow the additional effects of the mentioned DoFs. All subjects however reported a more difficult and uncomfortable walking when the horizontal pelvis motions were blocked. An additional motivation for keeping the DoFs despite these results is that they allow implementation of balance training.

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The feasibility of using exoskeletons in the performance of a simple task is discussed. The exoskeleton device has a total weight of 33 lb when unsupported, and it has seven joints. A Fitts’ law paradigm was used to characterize the tradeoff between speed and accuracy for the task. The results of tests with five subjects are given

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A new bipedal mobile robot design that combines the benefits of rolling, walking, and climbing locomotion is discussed. The design provides these locomotion primitives without the addition of actuators beyond those required for climbing through the use of a disk-like exoskeleton that provides a rolling surface. Small joint oscillations control the center of gravity of the robot in order to initiate and perpetuate quasi-static rolling motion. Simulation results are also included to validate this algorithm.

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An intelligent externally powered orthotic system (exoskeleton) for the treatment of motor dysfunctions of the upper extremities of stroke patients is described. IROS is an interactive and cooperative human-machine system, with both controlling the human arm. Initially, the machine is the main controller of the arm. As the patient improves, the human control of the arm increases, and the machine control of the arm decreases. The system combines the skills of professional therapists with a sensor-integrated orthosis and a real-time graphics system to ensure proper interaction and cooperation with the patient in order to achieve the goals of therapy. It uses the expertise of the therapists, which is incorporated into its knowledge system, while monitoring the sensory information from the patient, including the force, motion, and electromyogram (EMG) signals. The treatment-related tasks are displayed on the real-time graphic system to increase the interest and enhance the motivation of the patient. Such a system can be used to improve the rehabilitation process for stroke patients

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