A quasi-passive leg exoskeleton is presented for load-carrying augmen-tation during walking. The exoskeleton has no actuators, only ankle and hip springs and a knee variable-damper. Without a payload, the exoskeleton weighs 11.7 kg and requires only 2 Watts of electrical power during loaded walking. For a 36 kg payload, we demonstrate that the quasi-passive exoskeleton transfers on average 80% of the load to the ground during the single support phase of walking. By measuring the rate of oxygen consumption on a study participant walking at a self-selected speed, we find that the exoskeleton slightly increases the walking metabolic cost of transport (COT) as compared to a standard loaded backpack (10% increase). However, a similar exoskeleton without joint springs or damping control (zero-impedance exoskeleton) is found to increase COT by 23% compared to the loaded backpack, highlighting the benefits of passive and quasi-passive joint mechanisms in the design of efficient, low-mass leg exoskeletons.

(далее…)

Категория: Научные статьи | Нет комментариев »

Technological advances in robotic hardware and software have enabled powered exoskeletons to move from science fiction to the real world. The objective of this article is to emphasize two main points for future research. First, the design of future devices could be improved by exploiting biomechanical principles of animal locomotion. Two goals in exoskeleton research could parti-cularly benefit from additional physiological perspective: reduction in the metabolic energy expenditure of the user while wearing the device,and minimization of the power requirements for actuating the exoske-leton. Second, a reciprocal potential exists for robotic exoskeletons to advance our understanding of human locomotor physiology. Experimental data from humans walking and running with robotic exoskeletons could provide important insight into the metabolic cost of locomotion that is impossible to gain with other methods. Given the mutual benefits of collaboration, it is imperative that engineers and physiologists work together in future studies on robotic exoskeletons for human locomotion.

(далее…)

Категория: Научные статьи | Нет комментариев »

We are witnessing an unimaginably intensive development in the field of humanoid robotics. The field of active exoskeletons experiences also its renaissance and attracts an increasing attention of researchers worldwide. The objective of this article was to indicate the beginnings and review the history of the development of active exoskeletons, their original purpose and role in the systems for rehabilitation of severely handicapped persons. The present-day development of active exoskeletons has to a large extent determined their future and applications in both the military and some specific activities that come out of the frame of rehabilitation systems and go deeply into special systems for enhancing power and expanding physical and working capabilities of the man. However, the beginnings of robotics, and especially of humanoid robotics, did not foreshadow such a progress. We take a look back on the beginnings of the development of humanoid robots, especially bipedal locomotion systems and active exoskeletons, whose development marked the beginning of the research in the domain of humanoid robotics. Once more we point out some of our pioneering results in the domain of active exoske-letons that were originally dedicated to supporting locomotion of handicapped persons. We indicated the relationships between the initial research in the field of active rehabilitation techniques and contem-porary humanoid systems and tried to predict the future directions of the development of humanoid robotics and act ive exoskeletal systems and their applications.

(далее…)

Категория: Научные статьи | Нет комментариев »

The lower-limb muscle activities during the daily lower-limb motions such as sitting down, standing up, squatting, walking, ascending and descending stairs motions have been studied to enable power-assist robotic systems to estimate human lower-limb motions based on muscle electromyographic (EMG) signals. The relationship between the lower-limb motions and the acti-vity levels of main muscles con-cerning the daily lower-limb motions are analyzed in this study. The human intention for lower-limb motion can be estimated based on the activation pattern of lower-limb mus-cles. The analyzed results would be used to design the controllers of the lower-limb power-assist robotic systems for physically weak persons.

(далее…)

Категория: Научные статьи | Нет комментариев »

Background: Gait restoration is an integral part of rehabilitation of brain lesioned patients. Modern concepts favour a task-specific repetitive approach, i. e. who wants to regain walking has to walk, while tone-inhibiting and gait preparatory manoeuvres had domi-nated therapy before. Following the first mobilization out of the bed, the wheelchair-bound patient should have the possibility to practise complex gait cycles as soon as possible. Steps in this direction were treadmill training with partial body weight support and most recently gait machines enabling the repetitive training of even surface gait and even of stair climbing. Results: With treadmill training harness-secured and partially relieved wheelchair-mobilised patients could practise up to 1000 steps per session for the first time. Controlled trials in stroke and SCI pati-ents, however, failed to show a superior result when compared to walking exercise on the floor. Most like-ly explanation was the effort for the therapists, e.g. manually setting the paretic limbs during the swing phase resulting in a too little gait intensity. The next steps were gait machines, either consisting of a powered exoskeleton and a treadmill (Lokomat, AutoAmbulator) or an electromechanical solution with the harness secured patient placed on movable foot plates (Gait Trainer GT I). For the latter, a large multi-centre trial with 155 non-ambulatory stroke patients (DEGAS) revealed a superior gait ability and compe-tence in basic activities of living in the experimental group. The HapticWalker continued the end effector concept of movable foot plates, now fully programmable and equipped with 6 DOF force sensors. This device for the first time enables training of arbitrary walking situations, hence not only the simulation of floor walking but also for example of stair climbing and perturbations. Conclusion: Locomotor therapy is a fascinating new tool in rehabilitation, which is in line with modern principles of motor relearning pro-moting a task-specific repetitive approach. Sophisticated technical developments and positive randomized controlled trials form the basis of a growing acceptance worldwide to the benefits or our patients.

(далее…)

Категория: Научные статьи | 1 Комментарий »