Posts Tagged gait rehabilitation

[ARTICLE] A wearable somatosensory teaching device with adjustable operating force for gait rehabilitation training robot – Full Text

A novel wearable multi-joint teaching device for lower-limb gait rehabilitation is presented, intended to facilitate the adjustment of training modes in unique requirements of patients. A physiotherapist manipulates this active teaching device to plan the personalized gait trajectory and to construct the individual training mode. A haptic interaction joint module that stems from the friction braking principle is outlined here, with an adjustable operating force exerted by pneumatic film cylinders. With dual functions of somatosensory perception and teaching, it provides physiotherapist with a smooth and comfortable operation and a kind of force telepresence. The main contents are elaborated including the structural design and pneumatic proportional servo system of the teaching device and the joint module, operating force control principle, and gravity compensation method. Through performance tests of the prototype, the adjustable operating force has been demonstrated with the characteristics of good linearity and response speed. The results of master–slave control experiments preliminarily verified the effectiveness of the control approach. The research on the novel somatosensory teaching device with master–slave teaching mode has provided a concise, convenient, and efficient means for the clinical application of lower-limb rehabilitation robots, presumably as a new idea and technical supports for the future design.

Based on the neuroplasticity principle,1 a lower-limb rehabilitation training robot is a kind of automatic equipment that can recover or rebuild neural pathways2,3 for patients with motor dysfunction. The clinical presentation of a spinal cord injury (SCI) or a stroke comprises motor weakness or complete paresis, complete or partial loss of sensory function. The Swedish therapist Brunnstrom proposed the famous six-recovery-stage theory. Based on this theory, the training has different aims in the early stage of rehabilitation (flaccid paralysis stage), middle stage of rehabilitation (spasm stage), and later stage of rehabilitation (recovery stage). One major principle of neurological rehabilitation is that of motor learning. According to the principle of neural plasticity, repetitive and specific training tasks, which make the cerebral cortex learn and store the correct movement patterns, are important and effective. During rehabilitation, patients have to relearn motor tasks in order to overcome disability and limitations in the completion of daily activities. This is the theoretical basis of rehabilitation treatment. For a robot, the control strategy is provided diversely in different stages of rehabilitation to eliminate abnormal movement patterns. In the early rehabilitation, the passive training mode is usually adopted to help patients according to the predetermined trajectory and improve exercise capacity and reduce muscle atrophy. Then the active assist training mode begins for the patients of the middle recovery stage with moderate strength and relieving muscle spasm. In the later rehabilitation stage, the active resist training mode can be used to encourage patients to participate initiatively. The effect and importance of rehabilitation robots have been internationally recognized.48

Giving different state of an illness exhibited by hemiparetic individuals and the different training modes as mentioned above, the gait rehabilitation training robot primarily entails customized designing the parameters including movement trajectory, training speed and strength, and real-time perceiving, adjusting, and controlling. Lower-limb exoskeleton mechanism features of many degrees of freedom, together with the individual and condition differences of patients, so the problems are highlighted about how to accurately plan the correct gait trajectory and how to adjust training modes on time according to the progression. These issues become one of the research foci and technical difficulties of rehabilitation robot.

Most of the typical lower-limb rehabilitation robots in the world are autonomously controlled. The gait training mode planning for them is summarized in two methods, that is, preselected by a physiotherapist and dynamically adjusted by the algorithm. For some representative examples, the horizontal rehabilitation training robot Motion Maker9 can automatically guide patients along a preselected trajectory to perform passive flexion movement training on hip, knee, and ankle joints. The Lokomat1012 is a kind of body-weight-supported treadmill training (BWSTT) robot that adjusts the assisted power or reference trajectory by the impedance algorithm according to the patient interaction force. Patients can be made available to active and passive training mode. In the case of the lower extremity powered exoskeleton (LOPES) gait rehabilitation robot,13,14 limb reference trajectory is generated by instantaneous mapping with the healthy limb movement. The feasibility and functional improvements achieved in response to the emergence of such self-control rehabilitation robot; however, the existing technological bottleneck is obvious, that is, the limited adaptability of training mode.

The objective of this research is to develop a gait trajectory teaching device, with which the physiotherapist can directly and professionally teach to the robot and therefore present complex actions and adjust training modes as needed. Through master–slave teaching method, such system may provide the adaptability of the robot-mediated training and improve the treatment quality and efficiency, and decrease the difficulties in control algorithm study and the contradiction between the complex algorithms and real-time control.

Because of the more elaborate actions of the upper extremity and hand, teaching and playback technology is first applied to upper-limb rehabilitation training robot, for example, the flexible force feedback master–slave exoskeleton manipulator developed by America General Electric Company,15 the wearable master–slave training equipment of upper limbs driven by pneumatic artificial muscles in Okayama University in Japan,16 and the remotely operated upper-limb training robot of Southeast University in China.17 But there are fewer applications for lower-limb rehabilitation training. A single-joint ankle-foot orthoses designed by Canada, the Centre for Interdisciplinary Research in Rehabilitation and Social Integration is introduced in the literature.18The main cylinder driven by a motor controlled the slave cylinder to drive the orthoses. As described in a literature,19 a wearable master–slave lower-limb training robot driven by pneumatic artificial muscle achieves the teaching and training for the knee and ankle rehabilitation by sensors feeding back the trainer joint torque to the main control mechanism. In most of the studies mentioned above, the limitations existing in master–slave teaching for the lower-limb rehabilitation training robot can be summarized as follows: (1) the teaching device has the characteristics of complex structure, large quality and high inertia, so the physiotherapist is laborious and feels fatigue quickly, (2) the coordinate of the multi joints is demanded highly which may lead to the insufficient operating smoothness of the device, and (3) the feedback joint torque cannot be directly perceived by the physiotherapist but only as the control signal for the device.

In light of the above limitations, a novel multi-joint wearable teaching device is developed with adjustable operating force, which is exerted by light film cylinders. Based on the gravity compensation control method, a physiotherapist operates the teaching device to plan training trajectory smoothly and comfortably while also perceive the scene interaction force came from patients. In this manner, our research solved the existing problems, namely, the weight, the difficult manipulation of the teaching and the less force feedback to the physiotherapist. He operates the teaching device with the master–slave mode may provide various training modes fast and intuitively. The force telepresence from patients makes physiotherapist better controlling the training intensity and realizing the individual rehabilitation training consultation.

In this article, we elaborate five major contents that have been derived from this research as follows: master–slave teaching system solution, structural design of the multi-joint wearable master teaching device, operating force regulation principle and gravity compensation method, operating force regulation performance experiments, and master–slave control experiments.

Figure 1. System overall scheme.

Continue —> A wearable somatosensory teaching device with adjustable operating force for gait rehabilitation training robotAdvances in Mechanical Engineering – Bingjing Guo, Jianhai Han, Xiangpan Li, Peng Wu, Yanbin Zhang, Aimin You, 2017

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[ARTICLE] The Control of a Lower Limb Exoskeleton for Gait Rehabilitation: A Hybrid Active Force Control Approach – Full Text

Abstract

This paper focuses on the modelling and control of a three-link lower limb exoskeleton for gait rehabilitation. The exoskeleton that is restricted to the sagittal plane is modelled together with a human lower limb model. In this case study, a harmonic disturbance is excited at the joints of the exoskeleton whilst it is carrying out a joint space trajectory tracking. The disturbance is introduced to examine the compensating efficacy of the proposed controller. A particle swarm optimised active force control strategy is proposed to augment the disturbance regulation of a conventional proportional-derivative (PD) control law. The simulation study suggests that the proposed control approach mitigates well the disturbance effect whilst maintaining its tracking performance which is seemingly in stark contrast with its traditional PD counterpart.

Source: The Control of a Lower Limb Exoskeleton for Gait Rehabilitation: A Hybrid Active Force Control Approach

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[Conference Item] Wearable Haptic Devices For PostStroke Gait Rehabilitation

Abstract

Wearable technologies, in the form of small, light and inconspicuous devices, can be designed to help individuals suffering from neurological conditions carry out regular rehabilitation exercises. Current research has shown that walking to a rhythm can lead to significant improvements in various aspects of gait.

Our primary aim is to provide a suitable, technology based intervention to enhance gait rehabilitation of people with chronic and degenerative neurological health conditions (such as stroke). This intervention will be in the form of small, lightweight, wireless, wearable devices the user can take out of the clinic, extending their rehabilitation to their own home setting. The devices can deliver a series of vibrations at a steady rhythm giving the patient a more stable and symmetric pace of walking.

The simplest version of this approach typically comprise of a very small network of just two nodes and a central controller. The existing prototypes (called the Haptic Bracelets) capture and analyse motion data in real time to provide adaptive haptic (through vibrations) cueing. In the future and after more refinement, the system could allow a single therapist to monitor and advise groups of stroke survivors undergoing therapy sessions.

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Figure 1: A Haptic Bracelet device strapped on user’s leg.

Figure 2: Participant using the Haptic Bracelet devices

 

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[REVIEW] Powered robotic exoskeletons in post-stroke rehabilitation of gait: a scoping review – Full Text

Abstract

Powered robotic exoskeletons are a potential intervention for gait rehabilitation in stroke to enable repetitive walking practice to maximize neural recovery. As this is a relatively new technology for stroke, a scoping review can help guide current research and propose recommendations for advancing the research development.

The aim of this scoping review was to map the current literature surrounding the use of robotic exoskeletons for gait rehabilitation in adults post-stroke. Five databases (Pubmed, OVID MEDLINE, CINAHL, Embase, Cochrane Central Register of Clinical Trials) were searched for articles from inception to October 2015. Reference lists of included articles were reviewed to identify additional studies. Articles were included if they utilized a robotic exoskeleton as a gait training intervention for adult stroke survivors and reported walking outcome measures.

Of 441 records identified, 11 studies, all published within the last five years, involving 216 participants met the inclusion criteria. The study designs ranged from pre-post clinical studies (n = 7) to controlled trials (n = 4); five of the studies utilized a robotic exoskeleton device unilaterally, while six used a bilateral design. Participants ranged from sub-acute (<7 weeks) to chronic (>6 months) stroke. Training periods ranged from single-session to 8-week interventions. Main walking outcome measures were gait speed, Timed Up and Go, 6-min Walk Test, and the Functional Ambulation Category.

Meaningful improvement with exoskeleton-based gait training was more apparent in sub-acute stroke compared to chronic stroke. Two of the four controlled trials showed no greater improvement in any walking outcomes compared to a control group in chronic stroke.

In conclusion, clinical trials demonstrate that powered robotic exoskeletons can be used safely as a gait training intervention for stroke. Preliminary findings suggest that exoskeletal gait training is equivalent to traditional therapy for chronic stroke patients, while sub-acute patients may experience added benefit from exoskeletal gait training. Efforts should be invested in designing rigorous, appropriately powered controlled trials before powered exoskeletons can be translated into a clinical tool for gait rehabilitation post-stroke.

Background

Stroke is a leading cause of acquired disability in the world, with increasing survival rates as medical care and treatment techniques improve [1]. This equates to an increasing population with stroke-related disability [1, 2], who experience limitations in communication, activities of daily living, and mobility [3]. A majority of this population ranks recovering the ability to walk or improving walking ability among their top rehabilitation goals [4, 5]; furthermore, the ability to walk is a determining factor as to whether an individual is able to return home after their stroke [6]. However, 30 – 40 % of stroke survivors have limited or no walking ability even after rehabilitation [7, 8] and so there is an ongoing need to advance the efficacy of gait rehabilitation for stroke survivors.

Powered robotic exoskeletons are a recently developed technology that allows individuals with lower extremity weakness to walk [9]. These wearable robots strap to the legs and have electrically actuated motors that control joint motion to automate overground walking. Powered exoskeletons were originally designed to be used as an assistive device to allow individuals with complete spinal cord injury to walk [10]. However, because they allow for walking without overhead body weight support or a treadmill, they have gained attention as an alternate intervention for gait rehabilitation in other populations such as stroke where repetitive gait training has been shown to yield improvements in walking function [11, 12]. Several powered exoskeletons are already commercially available, such as the Ekso (Ekso Bionics, USA), Rewalk (Rewalk Robotics, Israel), and Indego (Parker Hannifin, USA) exoskeletons, with more being developed.

There have been many forms of gait retraining proposed for stroke survivors. Conventional physical therapy gait rehabilitation leads to improvements in speed and endurance [13], particularly when conducted early post-stroke [14]. However, conventional gait retraining using hands-on assistance can be taxing on therapists; the number of steps actually taken in a session reflects this and has been shown to be low in sub-acute hospital rehabilitation [15]. Many of the proposed technology-based gait intervention strategies have focused on reducing the physical strain to therapists while increasing the amount of walking repetition that individuals undergo. For example, body weight-supported treadmill training (BWSTT) allows therapists to manually move the hemiparetic limb in a cyclical motion while the patient’s trunk and weight are partially supported by an overhead harness system; this has shown improvements in stroke survivors’ gait speed and endurance compared to conventional gait training [16], yet still places a high physical demand on therapists. Advances in technology have led to treadmill-based robotics, such as the Lokomat (Hocoma, Switzerland), LOPES (University of Twente, Netherlands), and G-EO (Reha-Technology, Switzerland), which have bracing that attaches to the patient’s legs to take them through a walking motion on the treadmill. The appeal of this technology is that it can provide substantially higher repetitions for walking practice than BWSTT without placing strain on therapists; however, there is conflicting evidence regarding the efficacy of treadmill-based robotics for gait training compared to conventional therapy or BWSTT. Some studies have shown that treadmill robotics improve walking independence in stroke [17, 18] but do not improve speed or endurance [18, 19]. There has been some sentiment that such technology has not lived up to the expectations originally predicted based on theory and practice [20]. One argument is that these treadmill robotics with a pre-set belt speed, combined with body weight support, create an environment where the patient has less control over the initiation of each step [21]; another argument against treadmill-based gait training is the lack of variability in visuospatial flow, which is an essential challenge of overground walking [20]. Powered robotic exoskeletons, though similar in structure to treadmill-based robotics, differ in that they require active participation from the user for both swing initiation and foot placement; for example, some exoskeletons have control strategies which will only assist the stepping motion when it detects adequate lateral weight-shifting [9]. Furthermore, because the powered exoskeletons are used for overground walking, it requires the user to be responsible for maintaining trunk and balance control, as well as navigating their path over varying surfaces.

While these powered exoskeletons hold promise, the literature surrounding their use for gait training is only just beginning to gather, with the majority focusing on spinal cord injury [22, 23, 24]. Several [25, 26, 27] systematic reviews have shown safe usage, positive effects as an assistive device, and exercise benefits for individuals with spinal cord injury. Only one systematic review [28] specifically focusing on powered exoskeletons has included studies involving stroke participants, though studies in spinal cord injury and other conditions were also included. This review focused exclusively on the Hybrid Assistive Limb (HAL) exoskeleton (Cyberdyne, Japan), (which currently is not approved for clinical use outside of Japan), and found beneficial effects on gait function and walking independence; however, the results were combined generally across all included patient populations and not specifically for stroke.

Given that this is a relatively new intervention for stroke, the objective of this scoping review was to map the current literature surrounding the use of powered robotic exoskeletons for gait rehabilitation in post-stroke individuals and to identify gaps in the research. The second objective of this scoping review was to preliminarily explore the efficacy of exoskeleton-based gait rehabilitation in stroke. As this is a relatively new technology for stroke, a scoping review can help guide current research and propose recommendations for advancing the technology.

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Continue —> Powered robotic exoskeletons in post-stroke rehabilitation of gait: a scoping review | Journal of NeuroEngineering and Rehabilitation | Full Text

 

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Fig. 1 Study results: A flowchart of selection process based on inclusion/exclusion criteria

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[ARTICLE] Personalization of Gait Rehabilitation Games on a Pressure Sensitive Interactive LED Floor – Full Text PDF

Abstract

This paper describes the design and evaluation of a suite of movement-based games for gait rehabilitation with personalization based on gait characteristics. We used an eight by one meter pressure sensitive interactive LED floor. With the interactive games we attempted to steer different dimensions of people’s gait, increase motivation, provide an enjoying experience, and create an additional platform for gait rehabilitation by physical therapists. We performed several days of exploratory user tests with the created set of games, in total 56 patients and 30 therapists were involved. The set of games was positively received by therapists, who stated they could train a variety of targeted domains with it. Furthermore, many rehabilitants indicated they liked it more than normal training exercises. The possibilities for personalization and the variety of games allowed users with a wide variety of skills and limitations to train their gait, although not all rehabilitants could be offered an appropriate level of challenge. Nonetheless, we do believe one reason for the positive responses is that the games can be adapted to the rehabilitants’ gait characteristics with several settings in the games, and that a second reason seems to be that therapists can choose between games to target different aspects of rehabilitation suitable for the type of rehabilitant.

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[ARTICLE] Recent developments and challenges of lower extremity exoskeletons – Full Text HTML

Figure 2 Exoskeletons for locomotion assistance. (A) The ReWalk Wearable System (Image credit: ReWalk Robotics, Inc., Marlborough, MA, USA). (B) The lower extremity exoskeleton developed at the Chinese University of Hong Kong (Hong Kong, China).

Summary

The number of people with a mobility disorder caused by stroke, spinal cord injury, or other related diseases is increasing rapidly. To improve the quality of life of these people, devices that can assist them to regain the ability to walk are of great demand.

Robotic devices that can release the burden of therapists and provide effective and repetitive gait training have been widely studied recently. By contrast, devices that can augment the physical abilities of able-bodied humans to enhance their performances in industrial and military work are needed as well. In the past decade, robotic assistive devices such as exoskeletons have undergone enormous progress, and some products have recently been commercialized. Exoskeletons are wearable robotic systems that integrate human intelligence and robot power.

This paper first introduces the general concept of exoskeletons and reviews several typical lower extremity exoskeletons (LEEs) in three main applications (i.e. gait rehabilitation, human locomotion assistance, and human strength augmentation), and provides a systemic review on the acquisition of a wearer’s motion intention and control strategies for LEEs.

The limitations of the currently developed LEEs and future research and development directions of LEEs for wider applications are discussed.

Continue —> Recent developments and challenges of lower extremity exoskeletons – Journal of Orthopaedic Translation

Figure 3 Exoskeletons to augment human strength. (A) The Berkeley Lower Extremity Exoskeleton (BLEEX) (Image credit: Professor Kazerooni of the University of California, Berkeley, CA, USA). (B) The HEXAR-HL35 Exoskeleton (Image credit: Seungnam Yu of the Korea Atomic Energy Research Institute, Daejeon, Korea).

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[ARTICLE] Development of a Portable Gait Rehabilitation System for Home-visit Rehabilitaiton – Full Text PDF

Abstract

This paper describes the development of a gait rehabilitation system with a locomotion interface (LI) for home-visit rehabilitation. For this purpose, the LI should be compact, small and easy to move. The LI has two 2 Degree-Of-Freedom (DOF) manipulators with footpads to move each foot along a trajectory. When the user stands on the footpads, the system can move his or her feet while the body remains stationary. The footpads can have various trajectories, which are prerecordings of the
movements of healthy individuals walking on plane surfaces or slopes. The homes of stroke patients may not only have flat surfaces but also some slopes and staircases. The quadriceps femoris muscle is important for walking up and down slopes and
staircases, and the eccentric and concentric contractions of this muscle are, in particular, difficult to train under normal circumstances. Therefore, we developed a graded-walking program for the system used in this study. Using this system, the
user can undergo gait rehabilitation in their home, during visits by a physical therapist. An evaluation of the results of tests showed that the vastus medialis muscles of all the subjects were stimulated more than by walking on real slopes.

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[ARTICLE] Influence of motor imagery training on gait rehabilitation in sub-acute stroke: A randomized controlled trial – Full HTML

OBJECTIVE: To evaluate the effect of mental practice on motor imagery ability and assess the influence of motor imagery on gait rehabilitation in sub-acute stroke.

DESIGN: Randomized controlled trial.

SUBJECTS: A total of 44 patients with gait dysfunction after first-ever stroke were randomly allocated to a motor imagery training group and a muscle relaxation group.

METHODS: The motor imagery group received 6 weeks of daily mental practice. The relaxation group received a muscle relaxation programme of equal duration. Motor imagery ability and lower limb function were assessed at baseline and after 6 weeks of treatment. Motor imagery ability was tested using a questionnaire and mental chronometry test. Gait outcome was evaluated using a 10-m walk test (near transfer) and the Fugl-Meyer assessment (far transfer).

RESULTS: Significant between-group differences were found, with the vividness of kinesthetic imagery and the walking test results improving more in the motor imagery group than in the muscle relaxation group. There was no group interaction effect for the far transfer outcome score.

CONCLUSION: Motor imagery training may have a beneficial task-specific effect on gait function in sub-acute stroke; however, longer term confirmation is required.

via Influence of motor imagery training on gait rehabilitation in sub-acute stroke: A randomized controlled trial – Full HTML – Journal of Rehabilitation Medicine – Content.

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[A REVIEW] State-of-the-art robotic gait rehabilitation orthoses: Design and control aspects

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.

via State-of-the-art robotic gait rehabilitation orthoses: Design and control aspects – NeuroRehabilitation – IOS Press.

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[ARTICLE] State-of-the-art robotic gait rehabilitation orthoses: Design and control aspects

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.

via State-of-the-art robotic gait rehabilitation orthoses: Design and control aspects – NeuroRehabilitation – IOS Press.

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