This article presents a review of the methods used in recognition and analysis of the human gait from three different approaches: image processing, floor sensors and sensors placed on the body. Progress in new technologies has led the development of a series of devices and techniques which allow for objective evaluation, making measurements more efficient and effective and providing specialists with reliable information. Firstly, an introduction of the key gait parameters and semi-subjective methods is presented. Secondly, technologies and studies on the different objective methods are reviewed. Finally, based on the latest research, the characteristics of each method are discussed. 40% of the reviewed articles published in late 2012 and 2013 were related to non-wearable systems, 37.5% presented inertial sensor-based systems, and the remaining 22.5% corresponded to other wearable systems. An increasing number of research works demonstrate that various parameters such as precision, conformability, usability or transportability have indicated that the portable systems based on body sensors are promising methods for gait analysis.

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Gait analysis methods: an overview of wearable and non-wearable systems, highlighting clinical applications.

Technological advancements have led to the development of numerous wearable robotic devices for the physical assistance and restoration of human locomotion. While many challenges remain with respect to the mechanical design of such devices, it is at least equally challenging and important to develop strategies to control them in concert with the intentions of the user. This work reviews the state-of-the-art techniques for controlling portable active lower limb prosthetic and orthotic (P/O) devices in the context of locomotive activities of daily living (ADL), and considers how these can be interfaced with the user’s sensory-motor control system. This review underscores the practical challenges and opportunities associated with P/O control, which can be used to accelerate future developments in this field. Furthermore, this work provides a classification scheme for the comparison of the various control strategies. As a novel contribution, a general framework for the control of portable gait-assistance devices is proposed. This framework accounts for the physical and informatic interactions between the controller, the user, the environment, and the mechanical device itself. Such a treatment of P/Os – not as independent devices, but as actors within an ecosystem – is suggested to be necessary to structure the next generation of intelligent and multifunctional controllers. Each element of the proposed framework is discussed with respect to the role that it plays in the assistance of locomotion, along with how its states can be sensed as inputs to the controller. The reviewed controllers are shown to fit within different levels of a hierarchical scheme, which loosely resembles the structure and functionality of the nominal human central nervous system (CNS). Active and passive safety mechanisms are considered to be central aspects underlying all of P/O design and control, and are shown to be critical for regulatory approval of such devices for real-world use. The works discussed herein provide evidence that, while we are getting ever closer, significant challenges still exist for the development of controllers for portable powered P/O devices that can seamlessly integrate with the user’s neuromusculoskeletal system and are practical for use in locomotive ADL.

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Control strategies for active lower extremity prosthetics and orthotics: a review

Life expectancy in most countries has been increasing continually over the several few decades thanks to significant improvements in medicine, public health, as well as personal and environmental hygiene. However, increased life expectancy combined with falling birth rates are expected to engender a large aging demographic in the near future that would impose significant burdens on the socio-economic structure of these countries. Therefore, it is essential to develop cost-effective, easy-to-use systems for the sake of elderly healthcare and well-being. Remote health monitoring, based on non-invasive and wearable sensors, actuators and modern communication and information technologies offers an efficient and cost-effective solution that allows the elderly to continue to live in their comfortable home environment instead of expensive healthcare facilities. These systems will also allow healthcare personnel to monitor important physiological signs of their patients in real time, assess health conditions and provide feedback from distant facilities. In this paper, we have presented and compared several low-cost and non-invasive health and activity monitoring systems that were reported in recent years. A survey on textile-based sensors that can potentially be used in wearable systems is also presented. Finally, compatibility of several communication technologies as well as future perspectives and research challenges in remote monitoring systems will be discussed.

Wearable Sensors for Remote Health Monitoring.

The evaluation of rate of force development during rapid contractions has recently become quite popular for characterising explosive strength of athletes, elderly individuals and patients. The main aims of this narrative review are to describe the neuromuscular determinants of rate of force development and to discuss various methodological considerations inherent to its evaluation for research and clinical purposes. Rate of force development (1) seems to be mainly determined by the capacity to produce maximal voluntary activation in the early phase of an explosive contraction (first 50–75 ms), particularly as a result of increased motor unit discharge rate; (2) can be improved by both explosive-type and heavy-resistance strength training in different subject populations, mainly through an improvement in rapid muscle activation; (3) is quite difficult to evaluate in a valid and reliable way. Therefore, we provide evidence-based practical recommendations for rational quantification of rate of force development in both laboratory and clinical settings.

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Rate of force development: physiological and methodological considerations

Recently, cloud manufacturing (CMfg) as a new service-oriented manufacturing mode has been paid wide attention around the world. However, one of the key technologies for implementing CMfg is how to realize manufacturing resource intelligent perception and access. In order to achieve intelligent perception and access of various manufacturing resources, the applications of IoT technologies in CMfg has been investigated in this paper. The classification of manufacturing resources and services, as well as their relationships, are presented. A five-layered structure (i.e., resource layer, perception layer, network layer, service layer, and application layer) resource intelligent perception and access system based on IoT is designed and presented. The key technologies for intelligent perception and access of various resources (i.e., hard manufacturing resources, computational resources, and intellectual resources) in CMfg are described. A prototype application system is developed to valid the proposed method.

IoT-Based Intelligent Perception and Access of Manufacturing Resource Toward Cloud Manufacturing

A simple and reliable “turn-on” fluorescent sensor (E)-1-[((2-hydroxyethyl)imino) methyl] naphthalen-2-ol (HNP) has been designed, synthesized, and characterized by 1H-NMR, 13C-NMR, FT-IR, and EI-MS analysis. The binding property of HNP was examined employing UV–Vis and fluorescence spectroscopy. HNP exhibited high selectivity towards Al3+ among other cations and anions. The fluorescence titration experiment has established binding stoichiometry of HNP with Al3+ is 2:1, which can be further verified by HR-MS. The detection limit of HNP is 2.9 μM, and it can be reversible five-to-seven times to detect Al3+ without losing much efficiency which indicates that it can be a reliable probe for Al3+. Additionally, HNP was successfully applied for the detection of Al3+ in living cells. To achieve the detection of aluminum ion across a simple, reliable, and precise method, we have investigated the reversible detection (which can reversible response to Al3+ for five-to-seven times) of Al3+ through an extremely simple (requires only one-step reaction) “turn-on” fluorescent probe which enables us to visualize and analyze Al3+ with low detection limit (2.9 μM) and high selectivity in living cell without interference from the high abundant small biological molecules. 

A simple “turn-on” fluorescent sensor for reversible recognition of aluminum ion in living cell

Knee exoskeletons have gained increasing attention for gait training and intervention. The effectiveness of conventional rigid exoskeletons is degraded by bulkiness, high inertia, and joint misalignment. The soft configurations relax the constraints on the knee joint, thus circumvent the misalignment issue, and reduce the system size and weight. However, the soft exoskeletons sacrifice the load sharing capability from rigid support, and also the mechanical stop for constraining joint working range to avoid unsafe knee hyperextension. This article presents a novel rigid-soft hybrid exoskeleton to provide bidirectional interventions safely for knee joint motion. The design is lightweight (1.2 kg to wear), avoids the rigid rotation center that induces knee joint misalignment, has minimal impact on normal walking kinematics, and is able to provide support to the human body. A gait intervention strategy is designed under the hybrid model of human and exoskeleton. Comprehensive experiments are conducted to demonstrate the capability of the presented exoskeleton on gait intervention. 

Mechatronic Design and Control of a Rigid-Soft Hybrid Knee Exoskeleton for Gait Intervention

This paper presents a robotic trunk support system applying admittance control to assist trunk support and train the trunk core muscle groups. There are three degrees of freedom in the coronal plane, which allows lateral bending. The robotic trunk support system is designed based on a planer parallel manipulator. Position control makes the robot less flexible, and force control hardly maintains the position and orientation. The proposed admittance controller can improve the compliance of the robot and maintain the thorax at desired equilibrium. The experiments are conducted to evaluate the performance of the controller and the effect on the human body. The results demonstrate that the proposed wearable robotic brace can intervene in the activities of trunk core muscle groups and maintain trunk posture, which shows potential advantages in trunk support and rehabilitation.

Admittance Control of Wearable Robotic Brace for Dynamic Trunk Support

The invention relates to a flexible wire drive device which comprises a gear motor mechanism, a clutch mechanism, flexible wire wheel mechanisms and an elastic pre-tightening device The flexible wirewheel mechanisms comprise flexible wire wheels The flexible wire wheels are used for fixing one ends of flexible wires and are fixed to clutch shafts of the clutch mechanism and driven by the clutchshafts to rotate The clutch mechanism is in engaged connection with the output end of the gear motor mechanism Whether the clutch mechanism and the gear motor mechanism are engaged or not is controlled through on-off of a clutch of the clutch mechanism, and therefore on-off of torque transmission of the gear motor mechanism and the flexible wire wheels is controlled The elastic pre-tighteningdevice is a torsion elastic device, the twist center of the elastic pre-tightening device is fixed, and the twist outer portion of the elastic pre-tightening device is fixedly connected with the flexible wire wheels According to the flexible wire drive device, it can be guaranteed that a driven execution mechanism does not achieve self locking, the flexible wire wheels can be pre-tightened and cannot be wound, and the stroke range of the execution mechanism can be further adjusted

Flexible wire drive device

The myoelectric interface acts as an important role in the field of wearable robotics. This study explores the current-based sEMG technology for upper-limb motion recognition. Different from the voltage-based sEMG system, the current-based sampling approach can directly extract the current signals and be free from the cross talks. The technology facilitate the myoelectric sampling in a non-ideal environment such as underwater. We designed the sensing circuit with a feedback-loop current amplification module, and analyzed the stability. After development of the system, three healthy subjects participated in the experiment. Six basic wrist joint motions were investigated. With the selected feature set and the designed classification method, The average recognition accuracies across the subjects were 96.3%, 94.2%, and 95.8% respectively. The preliminary results demonstrate that the current-based sEMG technology is a promising solution to upper-limb motion recognition in a rigorous environment.

Qining Wang

Papers

A simple “turn-on” fluorescent sensor for reversible recognition of aluminum ion in living cell

Mechatronic Design and Control of a Rigid-Soft Hybrid Knee Exoskeleton for Gait Intervention

Admittance Control of Wearable Robotic Brace for Dynamic Trunk Support

Flexible wire drive device

A Current-Based Surface Electromyography (sEMG) System for Human Motion Recognition: Preliminary Study