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Introduction: Stroke-related deficits often include motor impairments and gait dysfunction, leading to a limitation of social activities and consequently affecting the quality of life of stroke survivors. Neurorehabilitation takes advantage of the contribution of different techniques in order to achieve more benefits for patients. Robotic devices help to improve the outcomes of physical rehabilitation. Moreover, motor imagery seems to play a role in neurological rehabilitation since it leads to the activation of the same brain areas as actual movements. This study investigates the use of a combined physical and cognitive protocol for gait rehabilitation in stroke patients. Methods: Specifically, we tested the efficacy of a 5-week training program using a robotic orthosis (P.I.G.R.O.) in conjunction with motor imagery training. Twelve chronic stroke patients participated in the study. We evaluated balance and gait performance before and after the training. Six of them underwent fMRI examination before and after the training to assess the effects of the protocol on brain plasticity mechanisms in motor and imagery tasks. Results: Our results show that the rehabilitation protocol can effectively improve gait performance and balance and reduce the risk of falls in stroke patients. Furthermore, the fMRI results suggest that rehabilitation is associated with cerebral plastic changes in motor networks. Discussion: The present findings, if confirmed by future research, have the potential to advance the development of new, more effective rehabilitation approaches for stroke patients, improving their quality of life and reducing the burden of stroke-related disability. [ABSTRACT FROM AUTHOR]

Robotic rehabilitation is a solution for recovery from neuromuscular diseases and supports physical therapists in performing high-intensity and repetitive training activities. The main reason for the limitations of rehabilitation robot utilization is economic factors because rehabilitation robot technology requires high levels of investment and relatively costly routine operation and maintenance. To facilitate widespread adoption of rehabilitation robots, low-cost, highly compliant, and simple-to-operate robotic rehabilitation devices are required. In this study, to introduce a novel alternative solution to the aforementioned problem, a low-cost, highly transparent, single pneumatic artificial muscle (PAM) actuated robotic therapy orthosis that enables the patient to perform all training modalities is introduced. A novel control approach was developed by combining admittance control and inverse-dynamics-based compliant controls. By means of simple counterweight loads and compliant control, quasi-static movement of the orthosis for active exercises is achieved for the full operation range of PAM without any jerky transitions. A new assist-active modality named “Patient Activated Assistance” (PAAM) was introduced, in which the patient was the master, and the exercise was performed as long as the patient was active, avoiding slacking. Assistance was provided by sharing the load force in accordance with the applied gain. The orthosis performance in realizing the training modalities was verified using surface electromyogram (sEMG) measurements. The results demonstrated that the proposed low-cost single-PAM-actuated robotic orthosis could be a solution to robotic rehabilitation demands, especially in low-middle-income countries (LMIC).

IntroductionStroke-related deficits often include motor impairments and gait dysfunction, leading to a limitation of social activities and consequently affecting the quality of life of stroke survivors. Neurorehabilitation takes advantage of the contribution of different techniques in order to achieve more benefits for patients. Robotic devices help to improve the outcomes of physical rehabilitation. Moreover, motor imagery seems to play a role in neurological rehabilitation since it leads to the activation of the same brain areas as actual movements. This study investigates the use of a combined physical and cognitive protocol for gait rehabilitation in stroke patients.MethodsSpecifically, we tested the efficacy of a 5-week training program using a robotic orthosis (P.I.G.R.O.) in conjunction with motor imagery training. Twelve chronic stroke patients participated in the study. We evaluated balance and gait performance before and after the training. Six of them underwent fMRI examination before and after the training to assess the effects of the protocol on brain plasticity mechanisms in motor and imagery tasks.ResultsOur results show that the rehabilitation protocol can effectively improve gait performance and balance and reduce the risk of falls in stroke patients. Furthermore, the fMRI results suggest that rehabilitation is associated with cerebral plastic changes in motor networks.DiscussionThe present findings, if confirmed by future research, have the potential to advance the development of new, more effective rehabilitation approaches for stroke patients, improving their quality of life and reducing the burden of stroke-related disability.

Powered lower limb orthoses have been commercially available for patients with Spinal Cord Injuries (SCI) or stroke. However, studies have shown that there are adverse effects on kinematics as well as metabolic energy of the users due to the additional mass of the orthoses to the lower limbs. Since additional metabolic energy required to use the powered orthoses is one of the reasons to avoid using them, it is important to reduce the mass and moment of inertia of the exoskeletons for longer use and better outcomes. In this study, a powered-lower-limb orthosis for stroke patients using a cable-differential mechanism, which is called COWALK-Mobile 2, was proposed. The cable-differential mechanism was utilized to transmit the actuating torques from actuators to the hip and knee joints. The cable-differential mechanism enabled the actuators to be located near the hip, which yields reduced inertia of the device, as well as the loads at the joints to be shared by the actuators, which results in smaller required actuator torque. Optimal radii of the pulleys for the cable-differential mechanism were found for efficient load-sharing during walking. Experimental results with a healthy person walking on a level surface have shown that larger joint torques were generated with smaller actuator torques.

Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human body; therefore, to understand certain design approaches, the anatomy and biomechanics of the hand are addressed in this paper. The control of these devices is also an arising challenge due to the implementation of intelligent systems and new rehabilitation techniques. This includes intention detection techniques (electroencephalography (EEG), electromyography (EMG), admittance) and estimating applied assistance. Therefore, this paper summarizes the technology in a systematic approach and reviews the state of the art of active hand exoskeletons with a focus on rehabilitation and assistive devices.

We previously proposeda power assist robot and conductedexperiments for cervical cord injury(CCI) patients. This paper proposed a new type of robot orthosis by making of their residual function around their shoulder in order to operate the wheelchair. A lock/unlock mechanism on the elbow joint is effectively used to transmit the residual function around the shoulder to the hand. We confirmedthat three patients with CCI could use their residual functionaround their shoulderand operate a wheelchair effectively in outdoor environment like high resistance roads and roads with a slope by measuring velocity of the wheelchair and electromyography of his shoulder muscle.

Background and Objectives: While body weight support (BWS) intonation is vital during conventional gait training of neurologically challenged subjects, it is important to evaluate its effect during robot assisted gait training. In the present research we have studied the effect of BWS intonation on muscle activities during robotic gait training using dynamic simulations. Methods: Two dimensional (2-D) musculoskeletal model of human gait was developed conjointly with another 2-D model of a robotic orthosis capable of actuating hip, knee and ankle joints simultaneously. The musculoskeletal model consists of eight major muscle groups namely; soleus (SOL), gastrocnemius (GAS), tibialis anterior (TA), hamstrings (HAM), vasti (VAS), gluteus maximus (GLU), uniarticular hip flexors (iliopsoas, IP), and Rectus Femoris (RF). BWS was provided at levels of 0, 20, 40 and 60% during the simulations. In order to obtain a feasible set of muscle activities during subsequent gait cycles, an inverse dynamics algorithm along with a quadratic minimization algorithm was implemented. Results: The dynamic parameters of the robot assisted human gait such as joint angle trajectories, ground contact force (GCF), human limb joint torques and robot induced torques at different levels of BWS were derived. The patterns of muscle activities at variable BWS were derived and analysed. For most part of the gait cycle (GC) the muscle activation patterns are quite similar for all levels of BWS as is apparent from the mean of muscle activities for the complete GC. Conclusions: Effect of BWS variation during robot assisted gait on muscle activities was studied by developing dynamic simulation. It is expected that the proposed dynamic simulation approach will provide important inferences and information about the muscle function variations consequent upon a change in BWS during robot assisted gait. This information shall be quite important while investigating the influence of BWS intonation on neuromuscular parameters of interest during robotic gait training. [ABSTRACT FROM AUTHOR]

It is a common hypothesis in the field of robot-assisted gait rehabilitation that the active involvement and voluntary participation of neurologically impaired subjects in the robotic gait training process may enhance the outcomes of such therapy. An adaptive seamless assist-as-needed (AAN) control scheme was developed for the robotic gait training. The AAN control scheme learns in real time the disability level of human subjects based on the trajectory tracking errors and adapts the robotic assistance accordingly. The overall AAN control architecture works on the basis of a robust adaptive control approach. The performance of seamless AAN control scheme was evaluated during treadmill training with a compliant robotic orthosis having six degrees of freedom. Two experiments, namely, trajectory following experiment and the AAN experiment were carried out to evaluate the performance of seamless adaptive AAN control scheme. It was found that the robotic orthosis is capable of guiding the subjects’ limbs on reference trajectories during the trajectory following experiment. Also, a variation in robotic assistance was recorded during the AAN experiment based on the voluntary participation of human subjects. This work is an advance on the current state of the art in the compliant actuation of robotic gait rehabilitation orthoses in the context of seamless AAN gait training. [ABSTRACT FROM AUTHOR]

In the last decades, wearable powered orthoses have been introduced in the state of the art for lower-limb rehabilitation. Most of these applications are driven by electric motors. Comparing with electric motor actuators, pneumatic artificial muscle (PAM) actuators are compliant because of the elasticity of PAMs. Consequently, for more safety and comfort of lower-limb rehabilitation, a compliant robotic orthosis powered by PAMs is developed. Based on safe control, a new control method, proxy-based sliding mode control (PSMC), was introduced into rehabilitation robotics a few years ago. It combined safety and accuracy of tracking to make it suitable for the safe control of PAM actuators. As the reason of low frequency response of PAM actuators and variable loads caused by different human subjects, the fixed parameters of PSMC makes the tracking performance vary from subject to subject, and lacks robustness. This paper presents a modification of PSMC by using neural network to tune PSMC gains online, and implements both PSMC and modified PSMC control schemes in the robotic orthosis. Experimental results demonstrate that the improved PSMC method performs better on tracking with little degradation on safety for different loads and human subjects. [ABSTRACT FROM AUTHOR]

The design of a new robotic orthosis to fully assist various overhead operations in the shipbuilding industry is proposed, and a dynamics simulation and an experimental study are conducted to validate the performance of impedance control of the new orthosis. There are considerable payloads from cables and reaction forces from injection parts during the blasting cleaning and painting in the shipbuilding process, and these can lead to work-related musculoskeletal disorders in the shoulder and elbow joints. Thus, in this research, the entire robotic orthosis designed for the dynamics simulation consists of joints with a total of 6 degrees of freedom (DOF): a 2-DOF shoulder, a 1-DOF elbow, and a 3-DOF wrist. The equations of motion of the designed robotic orthosis have been obtained on the basis of a relative-coordinate formulation. The contact force between the robotic orthosis and the human hand, gravitational force, and the control forces were considered as external forces. The results of the dynamics simulation are significant and show that the transient motions of robotic orthosis can be well controlled by using an impedance control scheme, while the compliance control is able to control only the steady-state motions. The control of transient motions is important because any unexpected impact forces or undesired dynamic behaviours in human–robot interactions may negatively affect both the worker's physical conditions and the quality of the work. Thus, in this research, we validate the suitability of the impedance control scheme in the described applications. Moreover, for simplicity of the experimental study and for considering the minimally required DOF in painting and blasting, only 3-DOF motions were considered in the dynamics simulation in this research. Finally, the obtained experimental results fully support the idea that the impedance control scheme is appropriate to control the robotic orthosis for overhead operations requiring a high degree of accuracy. [ABSTRACT FROM PUBLISHER]

BACKGROUND: Robot assisted gait training is a rapidly evolving rehabilitation practice. Various robotic orthoses have been developed during the past two decades for the gait training of patients suffering from neurologic injuries. These robotic orthoses can provide systematic gait training and reduce the work load of physical therapists. Biomechanical gait parameters can also be recorded and analysed more precisely as compared to manual physical therapy. OBJECTIVES: A review of robotic orthoses developed for providing gait training of neurologically impaired patients is provided in this paper. METHODS: Recent developments in the mechanism design and actuation methods of these robotic gait training orthoses are presented. Control strategies developed for these robotic gait training orthoses in the recent years are also discussed in detail. These control strategies have the capability to provide customised gait training according to the disability level and stage of rehabilitation of neurologically impaired subjects. RESULTS: A detailed discussion regarding the mechanism design, actuation and control strategies with potential developments and improvements is provided at the end of the paper. CONCLUSIONS: A number of robotic orthoses and novel control strategies have been developed to provide gait training according to the disability level of patients and have shown encouraging results. There is a need to develop improved robotic mechanisms, actuation methods and control strategies that can provide naturalistic gait patterns, safe human-robot interaction and customized gait training, respectively. Extensive clinical trials need to be carried out to ascertain the efficacy of these robotic rehabilitation orthoses. [ABSTRACT FROM AUTHOR]

Abstract: Robot assisted gait training may help in producing rapid improvements in functional gait parameters. This paper presents new experimental results with an intrinsically compliant robotic gait training orthosis. The newly developed robotic orthosis has 6 degrees of freedom (DOFs). A trajectory tracking controller based on the boundary layer augmented sliding control (BASMC) law was implemented to guide the subject’s limbs on physiological gait trajectories. The compliance of the robotic orthosis sagittal plane hip and knee joints was also controlled, independently of the trajectory tracking control. The robotic orthosis and the control scheme were evaluated on three neurologically intact subjects walking on a treadmill. A maximum trajectory tracking error of 10° was recorded at the hip and knee sagittal plane joints. The results showed that subjects can walk in the robotic orthosis with comfort and the BASMC law was able to guide the subject’s limbs on reference physiological trajectories. [Copyright &y& Elsevier]

Abstract: A new intrinsically compliant robotic orthosis powered by pneumatic muscle actuators (PMA) was developed for treadmill training of neurologically impaired subjects. The robotic orthosis has hip and knee sagittal plane rotations actuated by antagonistic configuration of PMA. The orthosis has passive mechanisms to allow vertical and lateral translations of the trunk and a passive hip abduction/adduction joint. A foot lifter having a passive spring mechanism was used to ensure sufficient foot clearance during swing phase. A trajectory tracking controller was implemented to evaluate the performance of the robotic orthosis on a healthy subject. The results show that the robotic orthosis is able to perform the treadmill training task by providing sufficient torques to achieve physiological gait patterns and a realistic stepping experience. The orthosis is a new addition to the rapidly advancing field of robotic orthoses for treadmill training. [Copyright &y& Elsevier]

A robotic orthosis has been developed for spinal cord injury patients which consists of an exoskeleton robotic suit with actuators at the hip and knee joints. In this article, a presentation is made on how to generate a gait pattern to control the robotic orthosis. First, the features needed to characterize a gait pattern are defined, and then a description is given of how to extract features from the normal gait patterns contained in experimental encoder data on the hip and knee joints of a person walking normally. Next, the physical meaning of these features in a gait pattern is discussed, and methods of varying the walking speed and step size through the adjustment of features are then considered. It is shown that the desired gait pattern can be obtained by connecting these features with spline interpolation. Finally, a crutch gait pattern is produced using these features, and this is applied to the exoskeleton robot ROBIN-P1 in order to verify the proposed method. [ABSTRACT FROM AUTHOR]

STUDY DESIGN:: Clinical study on six spinal cord-injured subjects. The performance of two automatic gait-pattern adaptation algorithms for automated treadmill training rehabilitation of locomotion (called DJATA1 and DJATA2) was tested and compared in this study. OBJECTIVES:: To test the performance of the two algorithms and to evaluate the corresponding patient satisfaction. We also wanted to evaluate the motivation of the patients to train with a fixed gait pattern versus training where they can influence and change the gait pattern (gait-pattern adaptation). SETTING:: Spinal Cord Injury Center Paracare, Balgrist, Zürich, Switzerland. METHODS:: The experimental data were collected during six blinded and randomized training trials (comprising three different conditions per algorithm) split into two training sessions per patient. During the experiments, we have recorded the time courses of the six parameters describing the adaptation. Additionally, a special patient questionnaire was developed that allowed us to collect data regarding the quality, perception, speed, and required effort of the adaptation, as well as patients’ opinion that addressed their motivation. The achieved adaptation was evaluated based on the time course of adaptation parameters and based on the patient questionnaire. A statistical analysis was made in order to quantify the data and to compare the two algorithms. RESULTS:: Significant adaptation of the gait pattern took place. The patients were in most cases able to change the gait pattern to a desired one and have always perceived the adaptation. No statistically significant differences were found between the performances of the two algorithms based on the evaluated data. However, DJATA2 achieved better adaptation scores. All patients preferred treadmill training with gait-pattern adaptation. CONCLUSION:: In the future, the patients would like to train with gait-pattern adaptation. Besides the subjective opinion indicating the choice of this training modality, gait-pattern adaptation also might lead to additional improvement of the rehabilitation of locomotion as it increases and promotes active training. SPONSORSHIP:: The work was supported by The Swiss Commission for Technology and Innovation (Project No. 4005.1).Spinal Cord (2003) 41, 657-666. doi:10.1038/sj.sc.3101518 [ABSTRACT FROM AUTHOR]

Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human body; therefore, to understand certain design approaches, the anatomy and biomechanics of the hand are addressed in this paper. The control of these devices is also an arising challenge due to the implementation of intelligent systems and new rehabilitation techniques. This includes intention detection techniques (electroencephalography (EEG), electromyography (EMG), admittance) and estimating applied assistance. Therefore, this paper summarizes the technology in a systematic approach and reviews the state of the art of active hand exoskeletons with a focus on rehabilitation and assistive devices. [ABSTRACT FROM AUTHOR]

Introduction/Background Gait training is one of the main objectives in rehabilitation of motor incomplete spinal cord injury (SCI). There are different modalities of locomotion training, being the robotic orthosis among them, and offering until now, positive outcomes. However there is still a lack of evidence of the optimal training characteristics. Objective To determine the effect of two different training programs with robotic gait orthosis for patients with chronic motor incomplete SCI. Material and method Study design: randomized, blinded to the observer, clinical trial. Patients from the National Institute of Rehabilitation (INR) with motor incomplete SCI, with at least 6 months of evolution and who were able to walk, were eligible. Patients were randomly assigned to either one of the two different training groups: 30 minutes or 60 minutes training group. Both groups received a training period of six weeks, five days a week. Assessments of gait pattern analysis with the GaitRite instrument, functional assessment with Spinal Cord Independence measure (SCIM), walking index for spinal cord injury (WISCI) and quality of life with life satisfaction questionnaire (Lisat-9); repeating such evaluations in a 6 and 12 months follow-up. Results In total, 12 participants were studied. After 30 training sessions with the robotic orthosis, both groups had significant improvements in gait as well as in SCIM, LISAT-9 and WISCI. No significant differences between groups were found. Conclusion Robotic orthosis gait training has a positive effect improving gait pattern in incomplete SCI. Until now, there are no significant differences between a 30 minutes and a 60 minutes-training program. [ABSTRACT FROM AUTHOR]