Showing papers on "Exoskeleton Device published in 2021"

Development of Active Lower Limb Robotic-Based Orthosis and Exoskeleton Devices: A Systematic Review

Abstract: The basic routine movements for elderly people are not easily accessible due to the weak muscles and impaired nerves in their lower extremity In the last few years, many robotic-based rehabilitation devices, like orthosis and exoskeletons, have been designed and developed by researchers to provide locomotion assistance to support gait behavior and to perform daily activities for elderly people However, there is still a need for improvement in the design, actuation and control of these devices for making them cost-effective in the worldwide market In this work, a systematic review is presented on available lower limb orthosis and exoskeleton devices, to date The devices are broadly reviewed according to joint types, actuation modes and control strategies Furthermore, tabular comparisons have also been presented with the types and applications of these devices Finally, the needful improvements for realizing the efficacy of lower limb rehabilitation devices are discussed along with the development stage This review will help the designers and researchers to develop an efficient robotic device for the rehabilitation of the lower limb

Low cost exoskeleton manipulator using bidirectional triboelectric sensors enhanced multiple degree of freedom sensory system.

Abstract: Rapid developments of robotics and virtual reality technology are raising the requirements of more advanced human-machine interfaces for achieving efficient parallel control. Exoskeleton as an assistive wearable device, usually requires a huge cost and complex data processing to track the multi-dimensional human motions. Alternatively, we propose a triboelectric bi-directional sensor as a universal and cost-effective solution to a customized exoskeleton for monitoring all of the movable joints of the human upper limbs with low power consumption. The corresponding movements, including two DOF rotations of the shoulder, twisting of the wrist, and the bending motions, are detected and utilized for controlling the virtual character and the robotic arm in real-time. Owing to the structural consistency between the exoskeleton and the human body, further kinetic analysis offers additional physical parameters without introducing other types of sensors. This exoskeleton sensory system shows a great potential of being an economic and advanced human-machine interface for supporting the manipulation in both real and virtual worlds, including robotic automation, healthcare, and training applications.

Passive Shoulder Exoskeletons: More Effective in the Lab Than in the Field?

Abstract: Shoulder exoskeletons potentially reduce overuse injuries in industrial settings including overhead work or lifting tasks. Previous studies evaluated these devices primarily in laboratory setting, but evidence of their effectiveness outside the lab is lacking. The present study aimed to evaluate the effectiveness of two passive shoulder exoskeletons and explore the transfer of laboratory-based results to the field. Four industrial workers performed controlled and in-field evaluations without and with two exoskeletons, ShoulderX and Skelex in a randomized order. The exoskeletons decreased upper trapezius activity (up to 46%) and heart rate in isolated tasks. In the field, the effects of both exoskeletons were less prominent (up to 26% upper trapezius activity reduction) while lifting windscreens weighing 13.1 and 17.0 kg. ShoulderX received high discomfort scores in the shoulder region and usability of both exoskeletons was moderate. Overall, both exoskeletons positively affected the isolated tasks, but in the field the support of both exoskeletons was limited. Skelex, which performed worse in the isolated tasks compared to ShoulderX, seemed to provide the most support during the in-field situations. Exoskeleton interface improvements are required to improve comfort and usability. Laboratory-based evaluations of exoskeletons should be interpreted with caution, since the effect of an exoskeleton is task specific and not all in-field situations with high-level lifting will equally benefit from the use of an exoskeleton. Before considering passive exoskeleton implementation, we recommend analyzing joint angles in the field, because the support is inherently dependent on these angles, and to perform in-field pilot tests. This paper is the first thorough evaluation of two shoulder exoskeletons in a controlled and in-field situation.

Symbitron Exoskeleton: Design, Control, and Evaluation of a Modular Exoskeleton for Incomplete and Complete Spinal Cord Injured Individuals

Abstract: In this paper, we present the design, control, and preliminary evaluation of the Symbitron exoskeleton, a lower limb modular exoskeleton developed for people with a spinal cord injury. The mechanical and electrical configuration and the controller can be personalized to accommodate differences in impairments among individuals with spinal cord injuries (SCI). In hardware, this personalization is accomplished by a modular approach that allows the reconfiguration of a lower-limb exoskeleton with ultimately eight powered series actuated (SEA) joints and high fidelity torque control. For SCI individuals with an incomplete lesion and sufficient hip control, we applied a trajectory-free neuromuscular control (NMC) strategy and used the exoskeleton in the ankle-knee configuration. For complete SCI individuals, we used a combination of a NMC and an impedance based trajectory tracking strategy with the exoskeleton in the ankle-knee-hip configuration. Results of a preliminary evaluation of the developed hardware and software showed that SCI individuals with an incomplete lesion could naturally vary their walking speed and step length and walked faster compared to walking without the device. SCI individuals with a complete lesion, who could not walk without support, were able to walk with the device and with the support of crutches that included a push-button for step initiation Our results demonstrate that an exoskeleton with modular hardware and control allows SCI individuals with limited or no lower limb function to receive tailored support and regain mobility.

Regulating Metabolic Energy Among Joints During Human Walking Using a Multiarticular Unpowered Exoskeleton

Abstract: Researchers have found that the walking economy can be enhanced by recycling ankle metabolic energy using an unpowered ankle exoskeleton. However, how to regulate multiarticular energy to enhance the overall energy efficiency of humans during walking remains a challenging problem, as multiarticular passive assistance is more likely to interfere with the human body’s natural biomechanics. Here we show that the metabolic energy of the hip and knee musculature can be regulated to a more energy-effective direction using a multiarticular unpowered exoskeleton that recycles negative mechanical energy of the knee joint in the late swing phase and transfers the stored energy to assist the hip extensors in performing positive mechanical work in the stance phase. The biarticular spring-clutch mechanism of the exoskeleton performs a complementary energy recycling and energy transfer function for hip and knee musculature. Through the phased regulation of the hip and knee metabolic energy, the target muscle activities decreased during the whole assistive period of the exoskeleton, which was the direct reason for 8.6 ± 1.5% (mean ± s.e.m) reduction in metabolic rate compared with that of walking without the exoskeleton. The proposed unpowered exoskeleton enhanced the user’s multiarticular energy efficiency, which equals improving musculoskeletal structure by adding a complementary loop for efficient energy recycling and energy transfer.

Design and Preliminary Assessment of a Passive Elastic Leg Exoskeleton for Resistive Gait Rehabilitation

Abstract: Objective: This article aimed to develop a unique exoskeleton to provide different types of elastic resistances (i.e., resisting flexion, extension, or bidirectionally) to the leg muscles during walking. Methods: We created a completely passive leg exoskeleton, consisting of counteracting springs, pulleys, and clutches, to provide different types of elastic resistance to the knee. We first used a benchtop setting to calibrate the springs and validate the resistive capabilities of the device. We then tested the device's ability to alter gait mechanics, muscle activation, and kinematic aftereffects when walking on a treadmill under the three resistance types. Results: Benchtop testing indicated that the device provided a nearly linear torque profile and could be accurately configured to alter the angle where the spring system was undeformed (i.e., the resting position). Treadmill testing indicated the device could specifically target knee flexors, extensors, or both, and increase eccentric loading at the joint. Additionally, these resistance types elicited different kinematic aftereffects that could be used to target user-specific spatiotemporal gait deficits. Conclusion: These results indicate that the elastic device can provide various types of targeted resistance training during walking. Significance: The proposed elastic device can provide a diverse set of resistance types that could potentially address user-specific muscle weaknesses and gait deficits through functional resistance training.

Effects of an industrial passive assistive exoskeleton on muscle activity, oxygen consumption and subjective responses during lifting tasks

Abstract: The purpose of this study was to evaluate the effects of an industrial passive assisted exoskeleton (IPAE) with simulated lifting tasks on muscle activity, oxygen consumption, perceived level of exertion, local perceived pressure, and systemic usability. Eight workers were required to complete two lifting tasks with and without the IPAE, that were single lifting tasks (repeated 5 times) and 15 min repeated lifting tasks respectively. Both of the tasks required subjects to remove a toolbox from the ground to the waist height. The test results showed that IPAE significantly reduced the muscle activity of the lumbar erector spinae, thoracic erector spinae, middle deltoid and labrum-biceps muscles; the reduction effect during the 15 min lifting task was reached 21%, 12%, 32% and 38% respectively. The exoskeleton did not cause significant differences in oxygen consumption and the perceived level of exertion, but local perceived pressure on the shoulders, thighs, wrists, and waist of the subjects could be produced. 50% of the subjects rated the usability of the equipment as acceptable. The results illustrate the good potential of the exoskeleton to reduce the muscle activity of the low back and upper arms. However, there is still a concern for the obvious contact pressure.

Design, Development, and Testing of an Intelligent Wearable Robotic Exoskeleton Prototype for Upper Limb Rehabilitation.

Abstract: Neuromotor rehabilitation and recovery of upper limb functions are essential to improve the life quality of patients who have suffered injuries or have pathological sequels, where it is desirable to enhance the development of activities of daily living (ADLs). Modern approaches such as robotic-assisted rehabilitation provide decisive factors for effective motor recovery, such as objective assessment of the progress of the patient and the potential for the implementation of personalized training plans. This paper focuses on the design, development, and preliminary testing of a wearable robotic exoskeleton prototype with autonomous Artificial Intelligence-based control, processing, and safety algorithms that are fully embedded in the device. The proposed exoskeleton is a 1-DoF system that allows flexion-extension at the elbow joint, where the chosen materials render it compact. Different operation modes are supported by a hierarchical control strategy, allowing operation in autonomous mode, remote control mode, or in a leader-follower mode. Laboratory tests validate the proper operation of the integrated technologies, highlighting a low latency and reasonable accuracy. The experimental result shows that the device can be suitable for use in providing support for diagnostic and rehabilitation processes of neuromotor functions, although optimizations and rigorous clinical validation are required beforehand.

Evaluation of a passive low-back support exoskeleton (Ergo-Vest) for manual waste collection.

Abstract: The purpose of study was to determine the biomechanical, physiological, and subjective effect of a Passive Exoskeleton device (called Ergo-Vest) among 20 waste collectors in the working environment. Compression force and moment on L4/L5 related to 400 critical postures of the participants were estimated using the 3DSSPP software. The heart rate and energy expenditure are measured as the physiological strain using the Polar RS400 Heart Rate Monitor. Borg scale perceived exertion, system usability scale, and ergonomic design indicators of the device were collected as the subjective parameters. Compression force and moment on L4/L5 disc were decreased when the Ergo-Vest was utilised. There was no significant difference in energy expenditure and heart rate with and without the device. The workers' perceived physical exertion was decreased while using the Ergo-Vest. From the perspective of end users, the usability and ergonomic design features of the Ergo-Vest was acceptable. Practitioner summary: The prevalence of musculoskeletal disorders is high among the Iranian waste collectors. To mitigate this occupational problem, the effect of a passive exoskeleton for lower-back support (Ergo-Vest) was investigated on the workers' spine loading, physiological parameters, and perceived physical exertion. The result shows spine force reduction and lower subjective responses.

Design and Evaluation of Torque Compensation Controllers for a Lower Extremity Exoskeleton.

Abstract: In this article, we present an integrated human-in-the-loop simulation paradigm for the design and evaluation of a lower extremity exoskeleton that is elastically strapped onto human lower limbs. The exoskeleton has three rotational DOFs on each side and weighs 23 kg. Two torque compensation controllers of the exoskeleton are introduced, aiming to minimize interference and maximize assistance, respectively. Their effects on the wearer's biomechanical loadings are studied with a running motion and predicted ground reaction forces (GRFs). It is found that the added weight of the passive exoskeleton substantially increases the wearer's musculoskeletal loadings. The maximizing assistance controller reduces the knee joint torque by 31% when compared with the normal running (without exoskeleton) and by 50% when compared with the passive exoskeleton case. When compared with the normal running, this controller also reduces the hip flexion and extension torques by 31% and 38%, respectively. As a result, the peak activations of the biceps short head, gluteus maximus, and rectus femoris muscles are reduced by more than a half. Nonetheless, the axial knee joint reaction force increases for all exoskeleton cases due to the added weight and higher ground reaction forces. In summary, the results provide sound evidence of the efficacy of the proposed controllers on reducing the wearer's musculoskeletal loadings. And it is shown that the human-in-the-loop simulation paradigm presented here can be used for virtual design and evaluation of powered exoskeletons and pave the way for building optimized exoskeleton prototypes for experimental evaluation.

An Anthropometrically Parameterized Assistive Lower Limb Exoskeleton.

Abstract: This paper presents an innovative design methodology for development of lower limb exoskeletons with the fabrication and experimental evaluation of prototype hardware. The proposed design approach is specifically conceived to be suitable for the pediatric population and uses additive manufacturing and a model parameterized in terms of subject anthropometrics to give a person-specific custom fit. The methodology is applied to create computer-aided design models using average anthropometrics of children 6-11 years old and using anthropometrics of an individual measured by the researchers. This demonstrates that the approach can scale to subject weight and height. A prototype exoskeleton is fabricated, which can actuate the hip and knee joints without restricting hip abduction-adduction motion. In order to test usability of the device and evaluate walking assistance, user effort is quantified in an assisted condition where the subject walks on a level treadmill with the exoskeleton powered. This is compared to an unassisted condition with the exoskeleton unpowered and a baseline condition with the subject not wearing the exoskeleton. Comparing assisted to baseline conditions, torque magnitudes increased at the hip and knee, mechanical energy generated increased at the hip but decreased at the knee, and muscle activations increased in the Vastus Lateralis but decreased in the Biceps Femoris. While the preliminary evidence for walking assistance is not entirely convincing for the tested conditions, the presented design methodology itself is promising as it has been successfully validated through the creation of computer-aided design models for children and fabrication of a serviceable exoskeleton prototype.

Knee Compliance Reduces Peak Swing Phase Collision Forces in a Lower-Limb Exoskeleton Leg: A Test Bench Evaluation

Abstract: Powered lower limb exoskeletons are a viable solution for people with a spinal cord injury to regain mobility for their daily activities. However, the commonly employed rigid actuation and pre-programmed trajectories increase the risk of falling in case of collisions with external objects. Compliant actuation may reduce forces during collisions, thus protecting hardware and user. However, experimental data of collisions specific to lower limb exoskeletons are not available. In this work, we investigated how a variable stiffness actuator at the knee joint influences collision forces transmitted to the user via the exoskeleton. In a test bench experiment, we compared three configurations of an exoskeleton leg with a variable stiffness knee actuator in (i) compliant or (ii) stiff configurations, and with (iii) a rigid actuator. The peak torque observed at the pelvis was reduced from 260.2 Nm to 116.2 Nm as stiffness decreased. In addition, the mechanical impulse was reduced by a factor of three. These results indicate that compliance in the knee joint of an exoskeleton can be favorable in case of collision and should be considered when designing powered lower limb exoskeletons. Overall, this could decrease the effort necessary to maintain balance after a collision, and improved collision handling in exoskeletons could result in safer use and benefit their usefulness in daily life.

RoboWalk: augmented human-robot mathematical modelling for design optimization

Abstract: Utilizing exoskeleton devices to help elderly or empower workers is a growing field of research in robotics. The structure of an exoskeleton can vary depending on user’s physical dimensions, joints...

Patients' and therapists' experience and perception of exoskeleton-based physiotherapy during subacute stroke rehabilitation: a qualitative analysis

Abstract: Purpose To explore the experience and acceptability of an exoskeleton-based physiotherapy program for non-ambulatory patients during subacute stroke rehabilitation from the perspective of patients and therapists. Materials and methods This was a qualitative descriptive study using semi-structured interviews and thematic analysis. Fourteen patients with stroke who participated in the experimental arm of a randomized controlled trial investigating the efficacy of exoskeleton-based physiotherapy were recruited. Six physiotherapists who provided the intervention were also recruited. Results Three themes were identified relating to the experience and acceptability of an exoskeleton-based physiotherapy program: (1) A matter of getting into the swing of things depicted the initial and ongoing learning process of using an exoskeleton; (2) More of a positive experience than anything else described the participants' mostly favorable attitude toward exoskeleton-based gait training; and (3) The best step forward captured participant-identified recommendations and considerations for the future integration of exoskeleton training into stroke rehabilitation. Conclusions Patients with stroke were even more optimistic than therapists toward the experience and benefits of exoskeleton-based gait training during subacute stroke rehabilitation. Future clinical practice should consider the balance between actual and perceived benefits, as well as the potential barriers to integrating an exoskeleton into stroke rehabilitation.IMPLICATIONS FOR REHABILITATIONPowered robotic exoskeletons can be used to provide higher duration and more repetitious walking practice for non-ambulatory patients with stroke.Patients with stroke view exoskeleton-based physiotherapy highly favorably, attributing greater opportunity and benefit to using the device during subacute rehabilitation.Physiotherapists should consider learning challenges, patient characteristics, and implementation barriers when integrating exoskeleton-based training within a treatment program.

The Kickstart Walk Assist System for improving balance and walking function in stroke survivors: a feasibility study.

Abstract: Compared with traditional physical therapy for stroke patients, lower extremity exoskeletons can provide patients with greater endurance and more repeatable and controllable training, which can reduce the therapeutic burden of the therapist. However, most exoskeletons are expensive, heavy or require active power to be operated. Therefore, a lighter, easy to wear, easy to operate, low-cost technology for stroke rehabilitation would be a welcome opportunity for stroke survivors, caregivers and clinicians. One such device is the Kickstart Walk Assist system and the purpose of this study was to determine feasibility of using this unpowered exoskeleton device in a sample of stroke survivors. Thirty stroke survivors were enrolled in the study and experienced walking with the Kickstart exoskeleton device that provided spring-loaded assistance during gait. After 5 days of wearing the exoskeleton, participants were evaluated in the two states of wearing and not wearing the exoskeleton. Outcome measures included: (a) spatio-temporal gait measures, (b) balance measures and (c) exoskeleton-use feedback questionnaire. In comparison to not wearing the device, when participants wore the Kickstart walking system, weight bearing asymmetry was reduced. The time spent on the 10-m walk test was also reduced, but there was no difference in the timed-up-and-go test (TUGT). Gait analysis data showed reduction in step time and double support time. Stroke survivors were positive about the Kickstart walking system’s ability to improve their balance, speed and gait. In addition, their confidence level and willingness to use the device was also positive. These findings show the feasibility of using the Kickstart walking system for improving walking performance in stroke survivors. Our future goal is to perform a longer duration study with more comprehensive pre- and post-testing in a larger sample of stroke survivors. Trial registration Chinese Clinical Trial Registry, ChiCTR2000032665. Registered 5 May 2020—Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=53288

An efficient force-feedback hand exoskeleton for haptic applications

Abstract: In this paper, a study on wearable exoskeleton devices which are capable of delivering sensation to the fingers while interacting with the virtual objects in virtual reality environment has been conducted. A force-controllable hand exoskeleton system is proposed, which is able to apply force feedback to the fingertip while allowing natural finger motions. The linkage structure was inspired by the skeletal structure of a human finger. Moreover, a series elastic actuator (SEA) mechanism, which consisted of a linear motor, a spring and a potentiometer, was presented as an actuating system. The force transmission through linkage has been investigated to ensure the force feedback ability at the fingertip. By using a PID controller, the proposed actuator module could generate the desired force in two different modes: free mode and interaction mode. The experimental results show that the proposed system could effectively deliver forces to the fingertips.

M-SAM: Miniature and Soft Artificial Muscle-Driven Wearable Robotic Fabric Exosuit for Upper Limb Augmentation

Abstract: Soft exoskeleton devices based on soft actuators have been attracting attention due to their safe human-machine interaction. However, current soft actuation technologies for exoskeleton devices are still limited due to low scalability and high hysteresis. This communication paper presents a new robotic fabric sleeve for upper limb assistance based on fabric garments and hydraulic-driven soft artificial muscles (SAMs) with low hysteresis. Experimental results show a highly linear relationship between input displacement of the syringe plunger and the muscle elongation. A simplified kinematic model was also developed to determine the elbow angle from the muscle length. A validation experiment with EMG signals showed that the assistive sleeve was able to reduce the workload to the user’s muscles. The artificial muscles and the assistive sleeve show great potential for applications in rehabilitation and activities of daily living (ADLs) assistance.

Effects of a Back-Support Exoskeleton on Pelvis-Thorax Kinematics and Coordination During Lifting

Abstract: We assessed the effects of a commercially available passive back support exoskeleton device on pelvis thorax kinematics and coordination. Eight male participants performed randomized block trials of 8 freestyle, symmetrical lifting tasks of a 13 kg container with or without use of the device. We obtained whole body kinematic data using an inertial motion capture system. We used Principal component analysis (PCA) to discern angular position and velocity waveform variations between conditions and assessed inter-segmental coordination using continuous relative phase measures. For joint angular position, only 1 PC exhibited statistical significance across conditions. This PC, which explained 10% of the loading vector variation, was interpreted as a phase shift feature. For joint angular velocity profiles, 2 PCs statistically differed between conditions. We interpreted these PCs as local magnitude difference features, particularly at the initial portion of the lift cycle. We did not detect a significant main effect of device usage or lifting phase on pelvis-thorax coordination. Our preliminary results suggest that use of a passive back support exoskeleton changes joint kinematics, but not inter-segment coordination during performance of a lifting task. These results may help understand device usability and interaction.

The Sensitivity Adjustment Technique within the Exoskeleton Control System

Abstract: An exoskeleton system contains a human operator in the control loop, which imposes restrictions on the applied control algorithms and movement speed. Robotics is the central topic of the latest physical artificial intelligence that links computing, biology, chemistry, material science, and mechanical engineering. This study explores the robotic exoskeleton system that contains a human operator in the control loop, which imposes restrictions on the applied control algorithms and movement speed. At the moment, there are several tasks in research projects toward exoskeleton control algorithms. These tasks include consideration of fatigue of a person arising from the control of the exoskeleton over a long period of time. Operator’s fatigue, as a result of the monotonous operations, leads to the fact that the control efficiency decreases and the positioning error will increase over time. Another task when controlling using human biopotentials is a compensation of the influence of the operator’s tremor on the control signal. In addition, a very important factor is the adaptation of actuators to a change in the transient characteristics of external and internal forces. This paper describes the results of tests of an arm exoskeleton device with DC drive located in the elbow joint and a control algorithm based on an electromyogram of the biceps brachii and triceps brachii of the operator. The structure and features of the experimental stand developed in the Laboratory of Robotics and Mechatronics of IPMech RAS are shown. The sensitivity adjustment technique within the exoskeleton control system is proposed.

Coupled exoskeleton assistance simplifies control and maintains metabolic benefits: a simulation study

Abstract: Assistive exoskeletons can reduce the metabolic cost of walking, and recent advances in exoskeleton device design and control have resulted in large metabolic savings. Most exoskeleton devices provide assistance at either the ankle or hip. Exoskeletons that assist multiple joints have the potential to provide greater metabolic savings, but can require many actuators and complicated controllers, making it difficult to design effective assistance. Coupled assistance, when two or more joints are assisted using one actuator or control signal, could reduce control dimensionality while retaining metabolic benefits. However, it is unknown which combinations of assisted joints are most promising and if there are negative consequences associated with coupled assistance. Since designing assistance with human experiments is expensive and time-consuming, we used musculoskeletal simulation to evaluate metabolic savings from multi-joint assistance and identify promising joint combinations. We generated 2D muscle-driven simulations of walking while simultaneously optimizing control strategies for simulated lower-limb exoskeleton assistive devices to minimize metabolic cost. Each device provided assistance either at a single joint or at multiple joints using massless, ideal actuators. To assess if control could be simplified for multi-joint exoskeletons, we simulated different control strategies in which the torque provided at each joint was either controlled independently or coupled between joints. We compared the predicted optimal torque profiles and changes in muscle and whole-body metabolic power consumption across the single joint and multi-joint assistance strategies. We found multi-joint devices–whether independent or coupled–provided 50% greater metabolic savings than single joint devices. The coupled multi-joint devices were able to achieve most of the metabolic savings produced by independently-controlled multi-joint devices. Our results indicate that device designers could simplify multi-joint exoskeleton designs by reducing the number of torque control parameters through coupling, while still maintaining large reductions in metabolic cost.

Comparison of end-effector and exoskeleton devices with robot-assisted gait training in patients with stroke

Abstract: Background/Aim: Loss of gait is the key problem after stroke. Robotic rehabilitation devices, which constitute the new treatment alternatives for stroke, can be divided into two groups on the basis of their design, the exoskeletons and end-effectors. This study aims to investigate the effects of gait training with two different types of robot on rehabilitation outcomes in patients with stroke. Methods: Twenty-four patients treated for stroke between December 2015 and December 2018 were included in the study. They were randomly divided into two groups for rehabilitation with either the exoskeleton or the end-effector. They attended the robotic rehabilitation programme for five days a week for six weeks, with each session lasting for 40 minutes. They were evaluated in terms of motor stage, ambulation, walking speed and walking capacity at the start and end of the programme. Results: According to baseline evaluations, there were higher scores in the endpoint evaluations for motor stage, ambulation, 6-minute walking test and lower scores in the endpoint evaluations for 10-meter walking test (P 0.05 for all). Conclusion: In patients with stroke, improvements were observed following robot-assisted gait training. No superiority was observed between the end-effector device with the exoskeleton device.

A Review on Robotic Hand Exoskeleton Devices: State-of-the-Art Method

Abstract: An exoskeleton is a device that helps the process of medical rehabilitation for people who have disorders in using their limbs. A low cost, effective sensor, control system, and an actuator are still the central issue in developing exoskeleton devices. This study aims to review an exoskeleton device, development, and recent technologies. The contribution of this study is that the paper can be used as a guideline to design an exoskeleton device. Specifically, the focus of this review discusses hand exoskeleton design. This review discusses three things, namely control signal, control mechanism, and exoskeleton actuator. In terms of the control signal, it addresses several techniques to control the exoskeleton by utilizing EMG, EEG, voice, and FSR (forced sensor) signals. In terms of control mechanism, several studies utilize pattern recognition based on machine learning and virtual reality to assist in using the exoskeleton. In terms of the actuator, the exoskeleton that was designed still has some shortcomings, namely weight and ergonomic design. The review results show that EMG signals are more often used in controlling exoskeleton devices. In the method section, pattern recognition using machine learning is still a significant part of the development of exoskeleton. In the actuator section, DC motors and linear actuators are more widely used than other types of motors. So, overall, the exoskeleton can still be improved from various aspects to make the subject more comfortable in use.

A Review: Sensory System, Data Processing, Actuator Type on a Hand Exoskeleton Design

Abstract: A rehabilitation device for a post-stroke is essential because stroke attacks can cause disable to part or half of the human body. An exoskeleton could be a vital device for rehabilitation for a post-stroke patient. Several studies have proposed the exoskeleton design for rehabilitation purposes to a human limb disorder. This study aims to review the state-of-the-art of hand exoskeleton devices based on myoelectric or any other sensors. This paper is expected to contribute to design a hand exoskeleton device using both myoelectric and force sensors. This was achieved by reviewing several articles related to the development of the exoskeleton, especially in the sensor system, data processing, and actuator system. The results show that the use of Ag electrode disposable Ag (AgCl) is still commonly found to detect the movement of the fingers on the hand because this sensor can reduce the artifact noise. The use of myo-armband is also found in several studies because it has wireless properties so that it is easy to use. In terms of processors, Arduino microcontrollers are more widely used than others. In order to activate the hand exoskeleton, servo motors are more widely used to actuate the finger joints, which is more precise than other actuators. In a further development, integration between exoskeleton systems and information systems will be an expected challenge. Furthermore, hopefully, the development of this exoskeleton can be applied as a rehabilitation device for patients with malfunction or hand paralysis.

The uses of lower limb exoskeleton, functional electrical stimulation, and future improvements for leg paralysis management – A systematic review

Abstract: Introduction: Ambulatory disability is one of the causes of depression and decreased quality of life. The common treatments used by patients are wheelchair, walker, forearm crutches, or immobilization in their house. Other orthoses such as knee ankle foot orthosis (KAFO) is very useful in certain conditions. Replacement therapy with a lower limb exoskeleton may increase the quality of life. The current review aims to evaluate the lower limb exoskeleton with or without functional electrical stimulation (FES) in assisting mobility in paraplegic patients. Methods: A search was performed to identify studies that compared lower limb exoskeleton to KAFO or hybrid exoskeleton with FES in paraplegic patients. Three publications were identified, with subjects ranging from 1 to 3 presenting with spinal injuries between T6 to T10. The measured parameters were locomotion ability, exoskeleton motor power, and torque. Results: The single-use of lower limb exoskeleton in paraplegia patients resulted in 15 sec faster (96s) Timed Up Go (TUG) test, 38 seconds faster (58s) 10-meter walked test (10MWT), and a 27 m farther 6-minute walked test (6MWT) compared to KAFO. The combination of exoskeleton with functional electrical stimulation (FES) reduces muscle fatigue and prevents muscle atrophy by providing stimulus to the muscle that imitates physiological stimulation by nerves. Discussion: Exoskeleton may assist disabled individuals in performing daily routine activity by improving gait, lessening exertion, and thus increasing the quality of life. Further improvement to exoskeleton devices includes integration with FES. Exoskeleton fit on the user also needs to be adjusted to user age and leg dimension to optimize movement and quality of life.