There are many robotic arms developed for providing care to physically disabled people. It is difficult to find robot designs in literature that articulate such a procedure. Therefore, it is our hope that the design work shown in this study may serve as a good example of a systematic method for rehabilitation robot design. Approach: The arm exoskeleton suit was developed to increase human’s strength, endurance, or speed enabling them to perform tasks that they previously could not perform. It should not impede the user’s natural motion and should be comfortable and safe to wear and easy to use. Although movement is difficult for them, they usually want to go somewhere by themselves. Results: The kinematic exoskeleton suit for human arms is simulated by MATLAB software. The exoskeleton suit of human arm consists of one link length, three link twists, two link offsets and three joint angles. Conclusion: This study introduced the kinematic of exoskeleton suit for human arm. The exoskeleton suit can be used to be instrument for anyone who needs to improve human’s performance. It will increase the strength of human that can lift heavy load or help handicapped patients, who cannot use their arm.

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Load measuring parts 50 and 52 are provided with reaction sensors 50a, 50b, 52a and 52b to measure loads at two positions, the tiptoe and the heel, on each sole of right and left feet of a wearing person 12. The reaction sensor 50a detects a reaction force to a load on a front side of the right foot (right tiptoe), the reaction sensor 50b detects a reaction force to a load on a rear side of the right foot (right heel), the reaction sensor 52a detects a reaction force to a load on a front side of the left foot (left tiptoe), and the reaction sensor 52b detects a reaction force to a load on a rear side of the left foot (left heel). The reaction sensors 50a, 50b, 52a and 52b are arranged to detect, based on a change of a capacitance, the loads on the right and left feet during a walk action. A change of the load accompanied with a shift of the weight and a contact between the wearing person’s foot and the ground can be detected.

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This paper deals with a comparative study on using water and air as actuation means for the control of a fluidic muscle (designed for air) and assesses the performance, parti-cularly from a dynamic and energetic point of view. A medium with higher bulk modulus such as oil/water is believed to increase pressure and force bandwidths and reduce sensitivity to load variations, as is the case with conventional hydraulic stiff actuation systems. However in this application the inherent flexibility of the muscle plays a major role. Water has been chosen because of its non-flammability, environmental friendliness and the low solubility of air in it. The operating pressure range of the pneumatic muscle is 0-6 bar (typical range of a pneumatic system) that is well below typical perating pressures of hydraulic systems (typically over 100 bar). At such low pressures the dynamic behaviour of water is less predictable because of the higher likelihood of entrapped air in the water which physically occurs when operating at low pressures. This can majorly affect water bulk modulus and hence its dynamic performance. Therefore, the behaviour of the system in this unconventional pressure range for a liquid must be more thoroughly investigated. Theoretical and experimental analyses on a dedicated test rig have been carried out to assess these assumptions.

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An artificial muscle (10) comprises a chamber (12) having a flexible wall of plastics material, a device for heating and/or cooling a low-boiling-point fluid contained in, or in communication with, the chamber so that at least some of the fluid changes state between liquid and gaseous so that the force in the chamber on the flexible wall changes and/or the flexible wall moves to change the volume of the chamber, and a tendon (14) which at least partly encircles the chamber over an extent that varies with variations in the chamber volume for transmitting force between the flexible wall and a load. The use of a low-boiling-point fluid operating at around its boiling point enables plastics materials to be used without thermal damage, and the use of plastics materials enables low production costs. The use of a flexible wall to convey an effort to a load avoids the need for sliding parts and can provide advantages such as reduced friction and ease of sealing. The use of a low-boiling-point fluid operating at around its boiling point also enables large changes in pressure to be achieved with relatively small changes in temperature, so that the muscle can operate over a relatively small temperature range. The use of a low-boiling-point fluid operating at around its boiling point also reduces the risk of personal injury. The tendon arrangement provides less of a restriction on the operating range of the muscle than a McKibben type arrangement.

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Patterns of stereotyped muscle coactivation, clinical-ly referred to as synergies, emerge following stroke and impair arm function. Although researchers have fo-cused on cortical contributions, there is growing evidence that altered stretch reflex pathways may also contribute to impairment. However, most previous reflex studies have focused on passive, single-joint move-ments without regard to their coordination during volitional actions. The purpose of this study was to exa-mine the effects of stroke on coordinated activity of stretch reflexes elicited in multiple arm muscles following multijoint perturbations. We hypothesized that cortical injury results in increased stretch ref-lexes of muscles characteristic of the abnormal flexor synergy during active arm conditions. To test this hypothesis, we used a robot to apply position perturbations to impaired arms of 10 stroke survivors and dominant arms of 8 healthy age-matched controls. Corresponding reflexes were assessed during volitional contractions simulating different levels of gravitational support, as well as during voluntary flexion and extension of the elbow and shoulder. Reflexes were quantified by average rectified surface electromyogram, recorded from eight muscles spanning the elbow and shoulder. Reflex coordination was quantified using an independent components analysis. We found stretch reflexes elicited in the stroke group were significantly less sensitive to changes in background muscle activation compared with those in the control group (P 0.05). We also observed significantly increased reflex coupling between elbow flexor and shoulder abduc-tor– extensor muscles in stroke subjects relative to that in control subjects. This increased coupling was present only during volitional tasks that required elbow flexion (P
0.001), shoulder extension (P 0.01), and gravity opposition (P
0.01), but not during the “no load” condition. During volitional contractions, reflex amplitudes scaled with the level of impairment, as assessed by Fugl-Meyer scores (r2  0.63; P 0.05). We conclude that altered reflex coordination is indicative of motor impairment level and may contri-bute to impaired arm function following stroke.

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