Development of closed-fitting-type walking assistance device for legs and evaluation of muscle activity

Tripping Avoidance Lower Extremity Exoskeleton Based on Virtual Potential Field for Elderly People

Tripping is a common problem that everyone faces when walking. This paper mainly focuses on a lower limb exoskeleton that can help those weak in joints to avoid tripping when negotiating stairs or stepping over obstacles. This method does not need a camera or map reconstruction to recognize the obstacles and plan paths. The exoskeleton applies an impedance controller to follow and control the pilot’s movements. A virtual potential field is proposed to help the robot regulate the pilot’s motion and avoid kicking the obstacles appearing in front of the pilot’s foot during walking. Simulation and experiments show that this method works effectively and could help the elderly and those affected by joint weakness avoid tripping when walking.

Pneumatic Quasi-Passive Actuation for Soft Assistive Lower Limbs Exoskeleton

There is a growing international interest in developing soft wearable robotic devices to improve mobility and daily life autonomy as well as for rehabilitation purposes. Usability, comfort and acceptance of such devices will affect their uptakes in mainstream daily life. The XoSoft EU project developed a modular soft lower-limb exoskeleton to assist people with low mobility impairments. This paper presents the bio-inspired design of a soft, modular exoskeleton for lower limb assistance based on pneumatic quasi-passive actuation. The design of a modular reconfigurable prototype and its performance are presented. This actuation centers on an active mechanical element to modulate the assistance generated by a traditional passive component, in this case an elastic belt. This study assesses the feasibility of this type of assistive device by evaluating the energetic outcomes on a healthy subject during a walking task. Human-exoskeleton interaction in relation to task-based biological power assistance and kinematics variations of the gait are evaluated. The resultant assistance, in terms of overall power ratio (Λ) between the exoskeleton and the assisted joint, was 26.6% for hip actuation, 9.3% for the knee and 12.6% for the ankle. The released maximum power supplied on each articulation, was 113.6% for the hip, 93.2% for the knee, and 150.8% for the ankle.

Mechanical Sensing for Lower Limb Soft Exoskeletons: Recent Progress and Challenges

Soft exoskeletons hold promise for facilitating monitoring and assistance in case of light impairment and for prolonging independent living. In contrast to rigid material-based exoskeletons, they strongly demand for new approaches of soft sensing and actuation solutions. This chapter overviews soft exoskeletons in contrast to rigid exoskeletons and focuses on the recent advancements on the movement monitoring in lower limb soft exoskeletons. Compliant materials and soft tactile sensing approaches can be utilized to build smart sensorized garments for joint angle measurements (needed for both control and monitoring). However, currently there are still several open challenges derived from the needed close interaction between the human body and the soft exoskeleton itself, especially related to how sensing function and robustness are strongly affected by wearability, which will need to be overcome in the near future.

Design and Evaluation of a Soft Assistive Lower Limb Exoskeleton

Wearable devices are fast evolving to address mobility and autonomy needs of elderly people who would benefit from physical assistance. Recent developments in soft robotics provide important opportunities to develop soft exoskeletons (also called exosuits) to enable both physical assistance and improved usability and acceptance for users. The XoSoft EU project has developed a modular soft lower limb exoskeleton to assist people with low mobility impairments. In this paper, we present the design of a soft modular lower limb exoskeleton to improve person’s mobility, contributing to independence and enhancing quality of life. The novelty of this work is the integration of quasi-passive elements in a soft exoskeleton. The exoskeleton provides mechanical assistance for subjects with low mobility impairments reducing energy requirements between 10% and 20%. Investigation of different control strategies based on gait segmentation and actuation elements is presented. A first hip–knee unilateral prototype is described, developed, and its performance assessed on a post-stroke patient for straight walking. The study presents an analysis of the human–exoskeleton energy patterns by way of the task-based biological power generation. The resultant assistance, in terms of power, was 10.9% ± 2.2% for hip actuation and 9.3% ± 3.5% for knee actuation. The control strategy improved the gait and postural patterns by increasing joint angles and foot clearance at specific phases of the walking cycle.

The effectiveness of powered, active lower limb exoskeletons in neurorehabilitation: A systematic review

OBJECTIVE

This review examines the utility of current active, powered, wearable lower limb exoskeletons as aids to rehabilitation in paraplegic patients with gait disorders resulting from central nervous system lesions.

METHODS

The PRISMA guidelines were used to review literature on the use of powered and active lower limb exoskeletons for neurorehabilitative training in paraplegic subjects retrieved in a search of the electronic databases PubMed, EBSCO, Web of Science, Scopus, ProQuest, and Google Scholar.

RESULTS

We reviewed 27 studies published between 2001 and 2014, involving a total of 144 participants from the USA, Japan, Germany, Sweden, Israel, Italy, and Spain. Seventy percent of the studies were experimental tests of safety or efficacy and 29% evaluated rehabilitative effectiveness through uncontrolled (22%) or controlled (7%) clinical trials.

CONCLUSIONS

Exoskeletons provide a safe and practical method of neurorehabilitation which is not physically exhausting and makes minimal demands on working memory. It is easy to learn to use an exoskeleton and they increase mobility, improve functioning and reduce the risk of secondary injury by reinstating a more normal gait pattern. A limitation of the field is the lack of experimental methods for demonstrating the relative effectiveness of the exoskeleton in comparison with other rehabilitative techniques and technologies.