A novel approach to stroke rehabilitation: robot-aided sensorimotor stimulation

Pediatric anklebot

In this paper we present the alpha-prototype of a novel pediatric ankle robot. This lower-extremity robotic therapy module was developed at MIT to aid recovery of ankle function in children with cerebral palsy ages 5 to 8 years old. This lower-extremity robotic module will commence pilot testing with children with cerebral palsy at Blythedale Childrens Hospital (Valhalla, NY), Bambino Gesu Children's Hospital (Rome, Italy), Riley Children's Hospital (Indianapolis, IN). Its design follows the same guidelines as our upper-extremity robots and adult anklebot designs, i.e. it is a low friction, backdriveable device with intrinsically low mechanical impedance. We show the ankle robot characteristics and stability range. We also present pilot data with healthy children to demonstrate the potential of this device.

Physically interactive robotic technology for neuromotor rehabilitation

Robotic technology can provide innovative responses to the severe challenges of providing cost-effective care to restore sensory-motor function following neurological and biomechanical injury. It may be deployed at several points on a continuum of care, to provide precisely controlled sensory-motor therapy to ameliorate disability and promote recovery of function, or to provide assistance to compensate for functions that cannot be recovered, or to replace limbs lost irretrievably. This chapter reviews recent progress using robotic technology to capitalize on neural plasticity and promote recovery after neurological injury such as stroke (cerebral vascular accident), research on brain-computer interfaces as a source of control signals for assistive technologies, and research on high-performance multiple-degree-of-freedom upper-extremity prosthetic limbs.

Influence of disturbances on the control of PC-mouse, goal-directed arm movements

This study concerns the influence of visuomotor rotating disturbance on motion dynamics and brain activity. It involves using a PC-mouse and introducing a predefined bias angle between the direction of motion of the mouse pointer and that of the screen cursor. Subjects were asked to execute three different tasks, designed to study the effect of visuomotor rotation on direction control, extent control or the two together. During each task, mouse movement, screen cursor movement and electroencephalograph (EEG) signals were recorded. An algorithm was used to detect and discard EEG signals contaminated by artifacts. Movement performance indexes and brain activity are used to evaluate motion control, tracking ability, learning and control. The results suggest the direction control is planned before the movement and controlled by an adaptive control while extent control is controlled by a real-time feedback. The measurements also confirm that increased motion and/or brain activity occur for bias angles in the ranges ±(90-120°) for both direction and extension controls. After-effects when changing the angle of visual rotation have been seen to be proportional to the variation in the adaptation angle.

Increasing viscosity and inertia using a robotically controlled pen improves handwriting in children

The aim of this study was to determine the effect of mechanical properties of the pen on quality of handwriting in children. A total of 22 school-aged children, aged 8 to 14 years, wrote in cursive using a pen attached to a robot. The robot was programmed to increase the effective weight (inertia) and viscosity of the pen. Speed, frequency, variability, and quality of the 2 handwriting samples were compared. Increased inertia and viscosity improved handwriting quality in 85% of children (P < or = .05). Handwriting quality did not correlate with changes in speed, suggesting that improvement was not due to reduced speed. Measures of movement variability remained unchanged, suggesting improvement was not due to mechanical smoothing of pen movement by the robot. Because improvement was not explained by reduced speed or mechanical smoothing, we conclude that children alter handwriting movements in response to pen mechanics. Altered movement could be caused by changes in sensory feedback.

Quality-of-life change associated with robotic-assisted therapy to improve hand motor function in patients with subacute stroke: a randomized clinical trial

BACKGROUND

At 6 months poststroke, most patients cannot incorporate their affected hand into daily activities, which in turn is likely to reduce their perceived quality of life.

OBJECTIVE

This preliminary study explored change in patient-reported, health-related quality of life associated with robotic-assisted therapy combined with reduced therapist-supervised training.

DESIGN AND SETTING

A single-blind, multi-site, randomized clinical trial was conducted.

PARTICIPANTS

Seventeen individuals who were 3 to 9 months poststroke participated.

INTERVENTION

Sixty hours of therapist-supervised repetitive task practice (RTP) was compared with 30 hours of RTP combined with 30 hours of robotic-assisted therapy.

MEASUREMENTS

Participants completed the Stroke Impact Scale (SIS) at baseline, immediately postintervention, and 2 months postintervention. Change in SIS score domains was assessed in a mixed model analysis.

RESULTS

The combined therapy group had a greater increase in rating of mood from preintervention to postintervention, and the RTP-only group had a greater increase in rating of social participation from preintervention to follow-up. Both groups had statistically significant improvement in activities of daily living and instrumental activities of daily living scores from preintervention to postintervention. Both groups reported significant improvement in hand function postintervention and at follow-up, and the magnitude of these changes suggested clinical significance. The combined therapy group had significant improvements in stroke recovery rating postintervention and at follow-up, which appeared clinically significant; this also was true for stroke recovery rating from preintervention to follow-up in the RTP-only group. LIMITATIONS OUTCOMES: of 30 hours of RTP in the absence of robotic-assisted therapy remain unknown.

CONCLUSION

Robotic-assisted therapy may be an effective alternative or adjunct to the delivery of intensive task practice interventions to enhance hand function recovery in patients with stroke.

Introducing a feedback training system for guided home rehabilitation

As the number of people requiring orthopaedic intervention is growing, individualized physiotherapeutic rehabilitation and adequate postoperative care becomes increasingly relevant. The chances of improvement in the patients condition is directly related to the performance and consistency of the physiotherapeutic exercises.

In this paper a smart, cost-effective and easy to use Feedback Training System for home rehabilitation based on standard resistive elements is introduced. This ensures high accuracy of the exercises performed and offers guidance and control to the patient by offering direct feedback about the performance of the movements.

46 patients were recruited and performed standard physiotherapeutic training to evaluate the system. The results show a significant increase in the patient's ability to reproduce even simple physiotherapeutic exercises when being supported by the Feedback Training System. Thus physiotherapeutic training can be extended into the home environment whilst ensuring a high quality of training.

Improving gait in multiple sclerosis using robot-assisted, body weight supported treadmill training

BACKGROUND

The majority of patients with multiple sclerosis (MS) develop progressive gait impairment, which can start early in the disease and worsen over a lifetime. A promising outpatient intervention to help improve gait function with potential for addressing this treatment gap is task-repetitive gait training.

METHODS

Body weight supported treadmill training (BWSTT) with or without robotic assistance (Lokomat) was tested using a randomized crossover design in 13 patients with relapsing-remitting, secondary progressive or primary progressive MS. Patients received 6 training sessions over 3 weeks of each intervention. Outcomes included changes in the timed 25-foot walk (T25FW), the 6-minute walk treadmill test (6MW) distance, the Kurtzke Expanded Disability Status Scale (EDSS), as well as double-limb support time and step length ratio.

RESULTS

There were no major differences in outcomes between treatment groups. The study population significantly improved on gait outcomes and the EDSS following BWSTT, including a 31% improvement in the T25FW, a 38.5% improvement in the 6MW, and a 1-point gain for the EDSS. Differences in pre/post changes were noted depending on gender, disease subtype, affected limb, and baseline EDSS.

CONCLUSIONS

Although no differences in gait outcomes or the EDSS were found between treatment groups, this small pilot study of task-repetitive gait training resulted in significant within-subject improvements. BWSTT appears to be an activity-dependent intervention with potential to reduce gait impairment in MS.

[Contributions of robotic devices to upper limb poststroke rehabilitation]

INTRODUCTION

Poststroke rehabilitation care has evolved considerably over the last decade. The emergence of the concepts of brain plasticity and motor learning has led to the development of new therapeutic approaches. Most of the new strategies are based on movement therapy, which can have a real impact on neurological recovery, sometimes with significant functional benefit for the patient.

STATE OF THE ART

In this context of evolving practices, the hemiplegic arm is the subject of special attention. Considering the often unfavorable "natural" prognosis and the relatively limited impact of conventional therapies; researchers have focused work on new alternatives. Cooperation between developers of technological advances and the medical community has led to the development of innovative therapeutic options often based on the use of specific technological tools (functional electric stimulation, virtual reality, transcranial magnetic stimulation...) to solicit or facilitate movement.

PERSPECTIVES/CONCLUSION

Robot-assisted rehabilitation lies within this scope. The positive results reported in the most recent publications and the growing interest for this type of therapy in the fields of medical and engineering research should open the way for extremely promising prospects. The technological performance of new robots has nevertheless raised a large number of unanswered questions, implying a significant amount of further research.

Robot-assisted task-specific training in cerebral palsy

Our goal was to examine the feasibility of applying therapeutic robotics to children and adults with severe to moderate impairment due to cerebral palsy (CP). Pilot results demonstrated significant gains for both groups. These results suggest that robot-mediated therapy may be an effective tool to ameliorate the debilitating effects of CP and provide new opportunities for reducing impairment and improving coordination.

Motor recovery after stroke: a systematic review

Loss of functional movement is a common consequence of stroke for which a wide range of interventions has been developed. In this Review, we aimed to provide an overview of the available evidence on interventions for motor recovery after stroke through the evaluation of systematic reviews, supplemented by recent randomised controlled trials. Most trials were small and had some design limitations. Improvements in recovery of arm function were seen for constraint-induced movement therapy, electromyographic biofeedback, mental practice with motor imagery, and robotics. Improvements in transfer ability or balance were seen with repetitive task training, biofeedback, and training with a moving platform. Physical fitness training, high-intensity therapy (usually physiotherapy), and repetitive task training improved walking speed. Although the existing evidence is limited by poor trial designs, some treatments do show promise for improving motor recovery, particularly those that have focused on high-intensity and repetitive task-specific practice.

Raised corticomotor excitability of M1 forearm area following anodal tDCS is sustained during robotic wrist therapy in chronic stroke

PURPOSE

Anodal transcranial direct current stimulation (tDCS) can transiently increase corticomotor excitability of intrinsic hand muscles and improve upper limb function in patients with chronic stroke. As a preliminary study, we tested whether increased corticomotor excitability would be similarly observed in muscles acting about the wrist, and remain present during robotic training involving active wrist movements, in six chronic stroke patients with residual motor deficit.

METHODS

Transcranial magnetic stimulation (TMS) generated motor evoked potentials (MEP) in the flexor carpi radialis (FCR) and provided a measure of corticomotor excitability and short-interval cortical inhibition (SICI) before and immediately after a period of tDCS (1 mA, 20 min, anode and TMS applied to the lesioned hemisphere), and robotic wrist training (1hr).

RESULTS

Following tDCS, the same TMS current strength evoked an increased MEP amplitude (mean 168 +/- 22%SEM; p < 0.05), that remained increased after robot training (166 +/- 23%; p < 0.05). Conditioned MEPs were of significantly lower amplitude relative to unconditioned MEPs prior to tDCS (62 +/- 6%, p < 0.05), but not after tDCS (89 +/- 14%, p = 0.40), or robot training (91 +/- 8%, p = 0.28), suggesting that the increased corticomotor excitability is associated with reduced intracortical inhibition.

CONCLUSION

The persistence of these effects after robotic motor training, indicates that a motor learning and retraining program can co-exist with tDCS-induced changes in cortical motor excitability, and supports the concept of combining brain stimulation with physical therapy to promote recovery after brain injury.

Kinematic robot-based evaluation scales and clinical counterparts to measure upper limb motor performance in patients with chronic stroke

BACKGROUND

Human-administered clinical scales are the accepted standard for quantifying motor performance of stroke subjects. Although they are widely accepted, these measurement tools are limited by interrater and intrarater reliability and are time-consuming to apply. In contrast, robot-based measures are highly repeatable, have high resolution, and could potentially reduce assessment time. Although robotic and other objective metrics have proliferated in the literature, they are not as well established as clinical scales and their relationship to clinical scales is mostly unknown.

OBJECTIVE

To test the performance of linear regression models to estimate clinical scores for the upper extremity from systematic robot-based metrics.

METHODS

Twenty kinematic and kinetic metrics were derived from movement data recorded with the shoulder-and-elbow InMotion2 robot (Interactive Motion Technologies, Inc), a commercial version of the MIT-Manus. Kinematic metrics were aggregated into macro-metrics and micro-metrics and collected from 111 chronic stroke subjects. Multiple linear regression models were developed to calculate Fugl-Meyer Assessment, Motor Status Score, Motor Power, and Modified Ashworth Scale from these robot-based metrics.

RESULTS

Best performance-complexity trade-off was achieved by the Motor Status Score model with 8 kinematic macro-metrics (R = .71 for training; R = .72 for validation). Models including kinematic micro-metrics did not achieve significantly higher performance. Performances of the Modified Ashworth Scale models were consistently low (R = .35-.42 for training; R = .08-.17 for validation).

CONCLUSIONS

The authors identified a set of kinetic and kinematic macro-metrics that may be used for fast outcome evaluations. These metrics represent a first step toward the development of unified, automated measures of therapy outcome.

Measuring changes of movement dynamics during robot-aided neurorehabilitation of stroke patients

The aim of this study was to describe in detail a new method, called normalized force control parameter (nFCP), to measure changes in movement dynamics obtained during robot-aided neurorehabilitation, and to evaluate its ability to estimate the clinical scales. The study was conducted in a group of 18 subjects after chronic stroke who underwent robot therapy of the upper limb. We used two different measures of movement dynamics to assess patients' performance during each session of training: the nFCP and force directional error (FDE), both measuring the directional error of the patient-exerted force applied to the end-effector of the robot device. Both metrics exhibited significant changes over the three-week course of treatment. The comparison between nFCP and FDE slopes showed a significant and high correlation ( r = 0.79; p < 0.001), indicating that the two parameters are closely correlated. The FDE informed on the direction of the force error, while the nFCP showed a better performance in predicting the clinical scale values. Assessment of the time course of recovery showed that nFCP, FDE and the movement smoothness improved quickly at first and then plateaued, while steady gains in mean velocity of movement took place over a longer time course. These data may be helpful to the therapist in developing more effective robot-based therapy protocols.

The effect of repeated measurements using an upper extremity robot on healthy adults

We are expanding the use of the MIT-MANUS robotics to persons with impairments due exclusively to orthopedic disorders, with no neurological deficits. To understand the reliability of repeated measurements of the robotic tasks and the potential for registering changes due to learning is critical. Purposes of this study were to assess the learning effect of repeated exposure to robotic evaluations and to demonstrate the ability to detect a change in protocol in outcome measurements. Ten healthy, unimpaired subjects (mean age = 54.1 +/- 6.4 years) performed six repeated evaluations consisting of unconstrained reaching movements to targets and circle drawing (with and without a visual template) on the MITMANUS. Reaching outcomes were aiming error, mean and peak speed, movement smoothness and duration. Outcomes for circle drawing were axis ratio metric and shoulder- elbow joint angles correlation metric (was based on a two-link model of the human arm and calculated hand path during the motions). Repeated-measures ANOVA (p < or = .05) determined if difference existed between the sessions. Intraclass correlations (R) were calculated. All variables were reliable, without learning across testing sessions. Intraclass correlation values were good to high (reaching, R > or =.80; circle drawing, R > or =.90). Robotic measurement ability to differentiate between similar but distinct tasks was demonstrated as measured by axis ratio metric (p < .001) and joint correlation metric (p = .001). Outcome measures of the MIT-MANUS proved to be reliable yet sensitive to change in healthy adults without motor learning over the course of repeated measurements.

Multicenter randomized trial of robot-assisted rehabilitation for chronic stroke: methods and entry characteristics for VA ROBOTICS

BACKGROUND

Chronic upper extremity impairment due to stroke has significant medical, psychosocial, and financial consequences, but few studies have examined the effectiveness of rehabilitation therapy during the chronic stroke period.

OBJECTIVE

. To test the safety and efficacy of the MIT-Manus robotic device for chronic upper extremity impairment following stroke.

METHODS

. The VA Cooperative Studies Program initiated a multicenter, randomized, controlled trial in November 2006 (VA ROBOTICS). Participants with upper extremity impairment >/=6 months poststroke were randomized to robot-assisted therapy (RT), intensive comparison therapy (ICT), or usual care (UC). RT and ICT consisted of three 1-hour treatment sessions per week for 12 weeks. The primary outcome was change in the Fugl-Meyer Assessment upper extremity motor function score at 12 weeks relative to baseline. Secondary outcomes included the Wolf Motor Function Test and the Stroke Impact Scale.

RESULTS

. A total of 127 participants were randomized: 49 to RT, 50 to ICT, and 28 to UC. The majority of participants were male (96%), with a mean age of 65 years. The primary stroke type was ischemic (85%), and 58% of strokes occurred in the anterior circulation. Twenty percent of the participants reported a stroke in addition to their index stroke. The average time from the index stroke to enrollment was 56 months (range, 6 months to 24 years). The mean Fugl-Meyer score at entry was 18.9.

CONCLUSIONS

. VA ROBOTICS demonstrates the feasibility of conducting multicenter clinical trials to rigorously test new rehabilitative devices before their introduction to clinical practice. The results are expected in early 2010.

Technology-assisted training of arm-hand skills in stroke: concepts on reacquisition of motor control and therapist guidelines for rehabilitation technology design

Background

It is the purpose of this article to identify and review criteria that rehabilitation technology should meet in order to offer arm-hand training to stroke patients, based on recent principles of motor learning.

Methods

A literature search was conducted in PubMed, MEDLINE, CINAHL, and EMBASE (1997–2007).

Results

One hundred and eighty seven scientific papers/book references were identified as being relevant. Rehabilitation approaches for upper limb training after stroke show to have shifted in the last decade from being analytical towards being focussed on environmentally contextual skill training (task-oriented training). Training programmes for enhancing motor skills use patient and goal-tailored exercise schedules and individual feedback on exercise performance. Therapist criteria for upper limb rehabilitation technology are suggested which are used to evaluate the strengths and weaknesses of a number of current technological systems.

Conclusion

This review shows that technology for supporting upper limb training after stroke needs to align with the evolution in rehabilitation training approaches of the last decade. A major challenge for related technological developments is to provide engaging patient-tailored task oriented arm-hand training in natural environments with patient-tailored feedback to support (re) learning of motor skills.

A perspective on intelligent devices and environments in medical rehabilitation

Globally, the number of people older than 65 years is anticipated to double between 1997 and 2025, while at the same time the number of people with disabilities is growing at a similar rate, which makes technical advances and social policies critical to attain, prolong, and preserve quality of life. Recent advancements in technology, including computation, robotics, machine learning, communication, and miniaturization of sensors have been used primarily in manufacturing, military, space exploration, and entertainment. However, few efforts have been made to utilize these technologies to enhance the quality of life of people with disabilities. This article offers a perspective of future development in seven emerging areas: translation of research into clinical practice, pervasive assistive technology, cognitive assistive technologies, rehabilitation monitoring and coaching technologies, robotic assisted therapy, and personal mobility and manipulation technology.

Assistive control system using continuous myoelectric signal in robot-aided arm training for patients after stroke

In some stroke rehabilitation programs, robotic systems have been used to aid the patient to train. In this study, a myoelectrically controlled robotic system with 1 degree-of-freedom was developed to assist elbow training in a horizontal plane with intention involvement for people after stroke. The system could provide continuous assistance in extension torque, which was proportional to the amplitude of the subject's electromyographic (EMG) signal from the triceps, and could provide resistive torques during movement. This study investigated the system's effect on restoring the upper limb functions of eight subjects after chronic stroke in a twenty-session rehabilitation training program. In each session, there were 18 trials comprising different combinations of assistive and resistive torques and an evaluation trial. Each trial consisted of five cycles of repetitive elbow flexion and extension between 90 degrees and 0 degrees at a constant velocity of 10 degrees/s. With the assistive extension torque, subjects could reach a more extended position in the first session. After 20 sessions of training, there were statistically significant improvements in the modified Ashworth scale, Fugl-Meyer scale for shoulder and elbow, motor status scale, elbow extension range, muscle strength, and root mean square error between actual elbow angle and target angle. The results showed that the twenty-session training program improved upper limb functions.

Electromechanical and robot-assisted arm training for improving arm function and activities of daily living after stroke

BACKGROUND

Electromechanical and robot-assisted arm training devices are used in rehabilitation and might help to improve arm function after stroke.

OBJECTIVES

To assess the effectiveness of electromechanical and robot-assisted arm training for improving activities of daily living and arm function and motor strength of patients after stroke, and the acceptability and safety of the therapy.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched October 2007), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2007), MEDLINE (1950 to October 2007), EMBASE (1980 to October 2007), CINAHL (1982 to October 2007), AMED (1985 to October 2007), SPORTDiscus (1949 to October 2007), PEDro (searched October 2007), COMPENDEX (1972 to October 2007) and INSPEC (1969 to October 2007). We also handsearched relevant conference proceedings, searched trials and research registers, checked reference lists, and contacted trialists, experts and researchers in our field, and manufacturers of commercial devices.

SELECTION CRITERIA

Randomised controlled trials comparing electromechanical and robot-assisted arm training for recovery of arm function with other rehabilitation interventions or no treatment for patients after stroke.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, assessed trial quality and extracted data. We contacted trialists for additional information. We analysed the results as standardised mean differences (SMDs) for continuous variables and relative risk differences (RD) for dichotomous variables.

MAIN RESULTS

We included 11 trials (328 participants) in this review. Electromechanical and robot-assisted arm training did not improve activities of daily living (SMD = 0.29; 95% confidence interval (CI) -0.47 to 1.06; P = 0.45; I(2 )= 85%). Arm motor function and arm motor strength improved (SMD = 0.68, 95% CI 0.24 to 1.11; P = 0.002; I(2 )= 56% and SMD = 01.03, 95% CI 0.29 to 1.78; P = 0.007; I(2 )= 79% respectively). Electromechanical and robot-assisted arm training did not increase the risk of patients to drop out (RD) (fixed-effect model) = 0.01; 95% CI -0.05 to 0.06; P = 0.77; I(2 )= 0.0%) and adverse events were rare.

AUTHORS' CONCLUSIONS

Patients who receive electromechanical and robot-assisted arm training after stroke are not more likely to improve their activities of daily living, but arm motor function and strength of the paretic arm may improve. However, the results must be interpreted with caution because there were variations between the trials in the duration, amount of training and type of treatment, and in the patient characteristics.

Mechanical arm trainer for the treatment of the severely affected arm after a stroke: a single-blinded randomized trial in two centers

OBJECTIVE

To test whether training with a new mechanical arm trainer leads to better outcomes than electrical stimulation of the paretic wrist extensors in subacute stroke patients with severe upper limb paresis. Electrical stimulation is a standard and reimbursable form of therapy in Germany.

DESIGN

Randomized controlled trial of 54 inpatients enrolled 4-8 wks from stroke onset, mean upper-extremity subsection of Fugl-Meyer assessment (0-66) at admission less than 18. In addition to standard care, all patients practiced 20-30 mins arm trainer or electrical stimulation every workday for 6 wks, totaling 30 sessions. Primary outcome was the Fugl-Meyer assessment, secondary outcomes were the Box and Block test, the Medical Research Council and the modified Ashworth scale, blindly assessed at enrollment, after 6 wks, and at 3-mo follow-up.

RESULTS

Both groups were homogeneous at study onset. Shoulder pain occurred in two arm trainer patients. The primary Fugl-Meyer assessment outcome improved for both groups over time (P < 0.001), but this improvement did not differ between groups. The initial (terminal) mean Fugl-Meyer assessment scores were 8.8 +/- 4.8 (19.2 +/- 14.5) for the arm trainer and 8.6 +/- 3.5 (13.6 +/- 7.9) for the electrical stimulation group. No patient could transport a block initially, but at completion significantly more arm trainer patients were able to transport at least three blocks (five vs. zero, P = 0.023). No significant differences were observed between the groups on the secondary Box and Block outcome at follow-up (eight vs. four patients). All Box and Block responders had an initial Fugl-Meyer assessment > or =10.

CONCLUSIONS

Arm trainer training did not lead to a superior primary outcome over electrical stimulation training. However, "good performers" on the secondary outcome seemed to benefit more from the arm trainer training.

The effect of the GENTLE/s robot-mediated therapy system on arm function after stroke

OBJECTIVE

To evaluate the effect of robot-mediated therapy on arm dysfunction post stroke.

DESIGN

A series of single-case studies using a randomized multiple baseline design with ABC or ACB order. Subjects (n = 20) had a baseline length of 8, 9 or 10 data points. They continued measurement during the B - robot-mediated therapy and C - sling suspension phases.

SETTING

Physiotherapy department, teaching hospital.

SUBJECTS

Twenty subjects with varying degrees of motor and sensory deficit completed the study. Subjects attended three times a week, with each phase lasting three weeks.

INTERVENTIONS

In the robot-mediated therapy phase they practised three functional exercises with haptic and visual feedback from the system. In the sling suspension phase they practised three single-plane exercises. Each treatment phase was three weeks long.

MAIN MEASURES

The range of active shoulder flexion, the Fugl-Meyer motor assessment and the Motor Assessment Scale were measured at each visit.

RESULTS

Each subject had a varied response to the measurement and intervention phases. The rate of recovery was greater during the robot-mediated therapy phase than in the baseline phase for the majority of subjects. The rate of recovery during the robot-mediated therapy phase was also greater than that during the sling suspension phase for most subjects.

CONCLUSION

The positive treatment effect for both groups suggests that robot-mediated therapy can have a treatment effect greater than the same duration of non-functional exercises. Further studies investigating the optimal duration of treatment in the form of a randomized controlled trial are warranted.

A new electromechanical trainer for sensorimotor rehabilitation of paralysed fingers: a case series in chronic and acute stroke patients

Background

The functional outcome after stroke is improved by more intensive or sustained therapy. When the affected hand has no functional movement, therapy is mainly passive movements. A novel device for repeating controlled passive movements of paralysed fingers has been developed, which will allow therapists to concentrate on more complicated tasks. A powered cam shaft moves the four fingers in a physiological range of movement.

Methods

After refining the training protocol in 2 chronic patients, 8 sub-acute stroke patients were randomised to receive additional therapy with the Finger Trainer for 20 min every work day for four weeks, or the same duration of bimanual group therapy, in addition to their usual rehabilitation.

Results

In the chronic patients, there was a sustained reduction in finger and wrist spasticity, but there was no improvement in active movements. In the subacute patients, mean distal Fugl-Meyer score (0–30) increased in the control group from 1.25 to 2.75 (ns) and 0.75 to 6.75 in the treatment group (p < .05). Median Modified Ashworth score increased 0/5 to 2/5 in the control group, but not in the treatment group, 0 to 0. Only one patient, in the treatment group, regained function of the affected hand. No side effects occurred.

Conclusion

Treatment with the Finger Trainer was well tolerated in sub-acute & chronic stroke patients, whose abnormal muscle tone improved. In sub-acute stroke patients, the Finger Trainer group showed small improvements in active movement and avoided the increase in tone seen in the control group. This series was too small to demonstrate any effect on functional outcome however.

Absence of a proximal to distal gradient of motor deficits in the upper extremity early after stroke

OBJECTIVE

Our first purpose was to determine whether there was a proximal to distal gradient in motor deficits in nine segments of the affected upper extremity (shoulder, elbow, forearm, wrist, and five fingers) post-stroke. Our second purpose was to determine which upper extremity segments made the greatest contributions to hand function.

METHODS

Thirty-three subjects were tested on average 18.6 (+/-5.6) days after stroke. The ability to move each segment was measured by active range of motion (AROM). Hand function was measured by a battery of standardized clinical tests which were synthesized into a single, sensitive score for hand function using principal component analysis.

RESULTS

AROM at all nine segments of the upper extremity was reduced and there was no evidence of a proximal to distal gradient in AROM values. Strength of each segment was reduced and there was also no evidence of a gradient in strength values. AROM at each segment was strongly correlated with hand function scores (range 0.76-0.94). General multiple regression analysis showed that AROM explained 82% of the variance in hand function, with most of the variance shared across proximal, middle, and distal segments. Hierarchical regression analysis showed that shoulder AROM alone could explain 88% of the variance in hand function.

CONCLUSIONS

Early after stroke a proximal to distal gradient of motor deficits was not present, and loss of hand function was due to a loss of ability to move many segments of the upper extremity and not just the distal ones.

SIGNIFICANCE

These results suggest that a change in the clinical perception of motor deficits post-stroke is needed. Our finding that shoulder AROM predicted almost all the variance in hand function opens up the possibility that this quick, simple measure may be predictive of future hand function. This would be of high economic and clinical utility compared to other ongoing efforts attempting to predict outcomes post-stroke (e.g. fMRI, MEG).

Quantitative evaluation of motor functional recovery process in chronic stroke patients during robot-assisted wrist training

This study was to investigate the motor functional recovery process in chronic stroke during robot-assisted wrist training. Fifteen subjects with chronic upper extremity paresis after stroke attended a 20-session wrist tracking training using an interactive rehabilitation robot. Electromyographic (EMG) parameters, i.e., EMG activation levels of four muscles: biceps brachii (BIC), triceps brachii (TRI, lateral head), flexor carpiradialis (FCR), and extensor carpiradialis (ECR) and their co-contraction indexes (CI) were used to monitor the neuromuscular changes during the training course. The EMG activation levels of the FCR (11.1% of decrease from the initial), BIC (17.1% of decrease from the initial), and ECR (29.4% of decrease from the initial) muscles decreased significantly during the training (P<0.05). Such decrease was associated with decreased Modified Ashworth Scores for both the wrist and elbow joints (P<0.05). Significant decrease (P<0.05) was also found in CIs of muscle pairs, BIC&TRI (21% of decrease from the initial), FCR&BIC (11.3% of decrease from the initial), ECR&BIC (49.3% of decrease from the initial). The decreased CIs related to the BIC muscle were mainly caused by the reduction in the BIC EMG activation level, suggesting a better isolation of the wrist movements from the elbow motions. The decreased CI of ECR& FCR in the later training sessions (P<0.05) was due to the reduced co-contraction phase of the antagonist muscle pair in the tracking tasks. Significant improvements (P<0.05) were also found in motor outcomes related to the shoulder/elbow and wrist/hand scores assessed by the Fugl-Meyer assessment before and after the training. According to the evolution of the EMG parameters along the training course, further motor improvements could be obtained by providing more training sessions, since the decreases of the EMG parameters did not reach a steady state before the end of the training. The results in this study provided an objective and quantitative EMG measure to describe the motor recovery process during poststroke robot-assisted wrist for the further understanding on the neuromuscular mechanism associated with the recovery.

Robot-assisted upper and lower limb rehabilitation after stroke: walking and arm/hand function

INTRODUCTION

Robots help to intensify motor rehabilitation of the upper and lower limbs after stroke. This article presents controlled studies relating to this topic, and an overview.

METHODS

A search was carried out for relevant randomized controlled trials, published between 1980 and 2007, on Medline (PubMed), Embase, and CINHAL.

RESULTS

Two studies showed benefit for an electromechanical gait trainer, with significantly more patients resuming walking as compared to conventional physiotherapy. Two studies showed no evidence of benefit for an exoskeleton-based system. A pooled analysis was not conducted due to the small numbers of studies and high heterogeneity. In arm/hand rehabilitation a number of unilateral or bilateral end-effector based systems proved effective in patients with stroke, and a simple one-dimensional system and a passive exoskeleton system proved effective in patients with chronic symptoms.

DISCUSSION

Robot-assisted motor rehabilitation after stroke appears promising. More trials, including comparative studies, are mandatory. The robot cannot be considered a substitute for the patient-therapist relationship.

Effects of robot-aided bilateral force-induced isokinetic arm training combined with conventional rehabilitation on arm motor function in patients with chronic stroke

OBJECTIVE

To analyze the effects of conventional rehabilitation combined with bilateral force-induced isokinetic arm movement training on paretic upper-limb motor recovery in patients with chronic stroke.

DESIGN

Single-cohort, pre- and postretention design.

SETTING

Rehabilitation department at a medical university.

PARTICIPANTS

Twenty subjects who had unilateral strokes at least 6 months before enrolling in the study.

INTERVENTION

A training program (40min/session, 3 sessions/wk for 8wk) consisting of 10 minutes of conventional rehabilitation and 30 minutes of robot-aided, bilateral force-induced, isokinetic arm movement training to improve paretic upper-limb motor function.

MAIN OUTCOME MEASURES

The interval of pretest, post-test, and retention test was set at 8 weeks. Clinical arm motor function (Fugl-Meyer Assessment [FMA], upper-limb motor function, Frenchay Arm Test, Modified Ashworth Scale), paretic upper-limb strength (grip strength, arm push and pull strength), and reaching kinematics analysis (peak velocity, percentage of time to peak velocity, movement time, normalized jerk score) were used as outcome measures.

RESULTS

After comparing the sets of scores, we found that the post-test and retention test in arm motor function significantly improved in terms of grip (P=.009), push (P=.001), and pull (P=.001) strengths, and FMA upper-limb scale (P<.001). Reaching kinematics significantly improved in terms of movement time (P=.015), peak velocity (P=.035), percentage of time to peak velocity (P=.004), and normalized jerk score (P=.008). Improvement in reaching ability was not sustained in the retention test.

CONCLUSIONS

Preliminary results showed that conventional rehabilitation combined with robot-aided, bilateral force-induced, isokinetic arm training might enhance the recovery of strength and motor control ability in the paretic upper limb of patients with chronic stroke.

Coactivations of elbow and shoulder muscles in hemiplegic persons with chronic stroke during robot-assisted training

The motor recovery procedure of chronic stroke during robot-assisted training has not been well studied previously. In this work, we analyzed the variations in the coactivating patterns of elbow and shoulder muscles (biceps, triceps lateral, anterior deltoid, and posterior deltoid) in hemiplegic persons with chronic stroke (n=4) during a 20-session's interactive robot-assisted treatment. Significant decreases in muscle cocontractions (P<0.05) for all muscle pairs started from the 8th session of the training. Improvements were also observed in motor scores of Fugl-Meyer and modified Ashworth scale after the treatment. The results suggested an increased dexterity and selective control on individual muscles for both elbow and shoulder joints in a designed task after the robot-assisted training.

Robot-aided neurorehabilitation: a robot for wrist rehabilitation

In 1991, a novel robot, MIT-MANUS, was introduced to study the potential that robots might assist in and quantify the neuro-rehabilitation of motor function. MIT-MANUS proved an excellent tool for shoulder and elbow rehabilitation in stroke patients, showing in clinical trials a reduction of impairment in movements confined to the exercised joints. This successful proof of principle as to additional targeted and intensive movement treatment prompted a test of robot training examining other limb segments. This paper focuses on a robot for wrist rehabilitation designed to provide three rotational degrees-of-freedom. The first clinical trial of the device will enroll 200 stroke survivors. Ultimately 160 stroke survivors will train with both the proximal shoulder and elbow MIT-MANUS robot, as well as with the novel distal wrist robot, in addition to 40 stroke survivor controls. So far 52 stroke patients have completed the robot training (ongoing protocol). Here, we report on the initial results on 36 of these volunteers. These results demonstrate that further improvement should be expected by adding additional training to other limb segments.

Botulinum toxin a, evidence-based exercise therapy, and constraint-induced movement therapy for upper-limb hemiparesis attributable to stroke: a preliminary study

OBJECTIVE

To determine whether the combination of botulinum toxin A (BTX-A) treatment for the upper limb and a 4-wk course of exercise therapy could improve motor function sufficiently to allow those with poststroke hemiparesis and spasticity to achieve the minimal motor criteria (MMC) to be enrolled in constraint-induced movement therapy (CIMT), and to determine the feasibility of enrolling participants into CIMT if they meet MMC after treatment with a combination of BTX-A plus exercise therapy.

DESIGN

Twelve individuals received BTX-A and exercise therapy for 1 hr/day, three times per week, for 4 wks. Those who met MMC were enrolled in 2 wks of CIMT, and the rest received a home exercise program. Outcome measures included the Ashworth Scale, Wolf Motor Function Test (WMFT), the Motor Activity Log (MAL), the Box and Blocks Test (BBT), and the upper-extremity subtest of the Fugl-Meyer Assessment of Motor Function (FM-UE).

RESULTS

Ashworth Scale scores declined from a mean score of 2.0-1.2 (P = 0.01). Four of 12 subjects were able to achieve MMC (P = 0.026). CIMT participants improved in the BBT, the MAL, and the WMFT compared with their own baseline. Gains achieved during CIMT receded by week 24 as spasticity returned.

CONCLUSION

BTX-A plus exercise therapy shows potential to improve function for those with severe hand paresis and spasticity after stroke. Those who meet MMC may initially realize further modest gains through CIMT. However, gains are likely to recede as spasticity returns. Adding medications or modifying the therapy protocol to include activities such as functional neuromuscular stimulation or robotic training may yield a more potent effect.

Effects of robot-assisted therapy on upper limb recovery after stroke: a systematic review

OBJECTIVE

The aim of the study was to present a systematic review of studies that investigate the effects of robot-assisted therapy on motor and functional recovery in patients with stroke.

METHODS

A database of articles published up to October 2006 was compiled using the following Medline key words: cerebral vascular accident, cerebral vascular disorders, stroke, paresis, hemiplegia, upper extremity, arm, and robot. References listed in relevant publications were also screened. Studies that satisfied the following selection criteria were included: (1) patients were diagnosed with cerebral vascular accident; (2) effects of robot-assisted therapy for the upper limb were investigated; (3) the outcome was measured in terms of motor and/or functional recovery of the upper paretic limb; and (4) the study was a randomized clinical trial (RCT). For each outcome measure, the estimated effect size (ES) and the summary effect size (SES) expressed in standard deviation units (SDU) were calculated for motor recovery and functional ability (activities of daily living [ADLs]) using fixed and random effect models. Ten studies, involving 218 patients, were included in the synthesis. Their methodological quality ranged from 4 to 8 on a (maximum) 10-point scale.

RESULTS

Meta-analysis showed a nonsignificant heterogeneous SES in terms of upper limb motor recovery. Sensitivity analysis of studies involving only shoulder-elbow robotics subsequently demonstrated a significant homogeneous SES for motor recovery of the upper paretic limb. No significant SES was observed for functional ability (ADL).

CONCLUSION

As a result of marked heterogeneity in studies between distal and proximal arm robotics, no overall significant effect in favor of robot-assisted therapy was found in the present meta-analysis. However, subsequent sensitivity analysis showed a significant improvement in upper limb motor function after stroke for upper arm robotics. No significant improvement was found in ADL function. However, the administered ADL scales in the reviewed studies fail to adequately reflect recovery of the paretic upper limb, whereas valid instruments that measure outcome of dexterity of the paretic arm and hand are mostly absent in selected studies. Future research into the effects of robot-assisted therapy should therefore distinguish between upper and lower robotics arm training and concentrate on kinematical analysis to differentiate between genuine upper limb motor recovery and functional recovery due to compensation strategies by proximal control of the trunk and upper limb.

Neural Correlates of Proprioceptive Integration in the Contralesional Hemisphere of Very Impaired Patients Shortly After a Subcortical Stroke: An fMRI Study

Background. The effects of physiotherapy are difficult to assess in very impaired early stroke patients. Objective. The aim of the study was to characterize the impact of 4 weeks of passive proprioceptive training of the wrist on brain sensorimotor activation after stroke. Methods. Patients with a subcortical ischemic lesion of the pyramidal tract were randomly assigned to a control or a wrist-training group. All patients had a single pure motor hemiplegia with severe motor deficit. The control group (6 patients) underwent standard Bobath rehabilitation. The second, “trained,” group (7 patients) received Bobath rehabilitation plus 4 weeks of proprioceptive training with daily passive calibrated wrist extension. Before and after the training period, patients were examined with validated clinical scales and functional MRI (fMRI) while executing a passive movement versus rest. The effect of standard rehabilitation on sensorimotor activation was assessed in the control group on the wrist, and the effect of standard rehabilitation plus proprioceptive training was assessed in the trained group. The effect of 4-week proprioceptive training alone was statistically evaluated by difference between groups. Results. Standard rehabilitation along with natural recovery mainly led to increases in ipsilesional activation and decreases in contralesional activation. On the contrary, standard rehabilitation and paretic wrist proprioceptive training increased contralesional activation. Proprioceptive training produced change in the supplementary motor area (SMA), prefrontal cortex, and a contralesional network including inferior parietal cortex (lower part of BA 40), secondary sensory cortex, and ventral premotor cortex (PMv). Conclusion. We have demonstrated that purely passive proprioceptive training applied for 4 weeks is able to modify brain sensorimotor activity after a stroke. This training revealed fMRI change in the ventral premotor and parietal cortices of the contralesional hemisphere, which are secondary sensorimotor areas. Recent studies have demonstrated the crucial role of these areas in severely impaired patients. We propose that increased contralesional activity in secondary sensorimotor areas likely facilitates control of recovered motor function by simple proprioceptive integration in those patients with poor recovery.

Design and Characterization of Hand Module for Whole-Arm Rehabilitation Following Stroke

In 1991, a novel robot named MIT-MANUS was introduced as a test bed to study the potential of using robots to assist in and quantify the neurorehabilitation of motor function. It introduced a new modality of therapy, offering a highly backdrivable experience with a soft and stable feel for the user. MIT-MANUS proved an excellent fit for shoulder and elbow rehabilitation in stroke patients, showing a reduction of impairment in clinical trials with well over 300 stroke patients. The greatest impairment reduction was observed in the group of muscles exercised. This suggests a need for additional robots to rehabilitate other target areas of the body. Previous work has expanded the planar MIT-MANUS to include an antigravity robot for shoulder and elbow, and a wrist robot. In this paper we present the "missing link": a hand robot. It consists of a single-degree-of-freedom (DOF) mechanism in a novel statorless configuration, which enables rehabilitation of grasping. The system uses the kinematic configuration of a double crank and slider where the members are linked to stator and rotor; a free base motor, i.e., a motor having two rotors that are free to rotate instead of a fixed stator and a single rotatable rotor (dual-rotor statorless motor). A cylindrical structure, made of six panels and driven by the relative rotation of the rotors, is able to increase its radius linearly, moving or guiding the hand of the patients during grasping. This module completes our development of robots for the upper extremity, yielding for the first time a whole-arm rehabilitation experience. In this paper, we will discuss in detail the design and characterization of the device.

Assessing mechanisms of recovery during robot-aided neurorehabilitation of the upper limb

OBJECTIVE

The present study aimed to qualify and quantify the different components of motor recovery in a group of stroke patients treated by robot-aided techniques. In addition, the learning model of each motor recovery component was analyzed.

METHODS

Two groups of poststroke patients were treated with the use of an elbow-shoulder manipulator, respectively, within (recent) and after (chronic) the first 6 months of their cerebrovascular accident. Both groups were evaluated by means of standard clinical assessment scales and a robot-measured evaluation method.

RESULTS

These findings confirm that motor training consisting of voluntary movements assisted by the robot device led to significant improvements in motor performance in terms of the kinematic and dynamic components of the arm movements. This corresponded to improvement of impairment as confirmed by the clinical scale results.

CONCLUSIONS

Knowledge of the recovery components and of the associated performance acquisition model may be useful in assessing and training stroke patients and should make it possible to precisely plan and, if necessary, modify the rehabilitation strategies.

Robot-aided rehabilitation of neural function in the upper extremities

Repetitive movements can improve muscle strength and movement coordination in patients with neurological disorders and impairments. Robot-aided approaches can serve to enhance the rehabilitation process. They can not only improve the therapeutic outcome but also support clinical evaluation and increase the patient motivation. This chapter provides an overview of existing systems that can support the movement therapy of the upper extremities in subjects with neurological pathologies. The devices are compared with respect to technical function, clinical applicability, and clinical outcomes.

Stochastic estimation of arm mechanical impedance during robotic stroke rehabilitation

This paper presents a stochastic method to estimate the multijoint mechanical impedance of the human arm suitable for use in a clinical setting, e.g., with persons with stroke undergoing robotic rehabilitation for a paralyzed arm. In this context, special circumstances such as hypertonicity and tissue atrophy due to disuse of the hemiplegic limb must be considered. A low-impedance robot was used to bring the upper limb of a stroke patient to a test location, generate force perturbations, and measure the resulting motion. Methods were developed to compensate for input signal coupling at low frequencies apparently due to human-machine interaction dynamics. Data was analyzed by spectral procedures that make no assumption about model structure. The method was validated by measuring simple mechanical hardware and results from a patient's hemiplegic arm are presented.

Electromyography-Controlled Exoskeletal Upper-Limb–Powered Orthosis for Exercise Training After Stroke

OBJECTIVE

Robot-assisted exercise shows promise as a means of providing exercise therapy for weakness that results from stroke or other neurological conditions. Exoskeletal or "wearable" robots can, in principle, provide therapeutic exercise and/or function as powered orthoses to help compensate for chronic weakness. We describe a novel electromyography (EMG)-controlled exoskeletal robotic brace for the elbow (the active joint brace) and the results of a pilot study conducted using this brace for exercise training in individuals with chronic hemiparesis after stroke.

DESIGN

Eight stroke survivors with severe chronic hemiparesis were enrolled in this pilot study. One subject withdrew from the study because of scheduling conflicts. A second subject was unable to participate in the training protocol because of insufficient surface EMG activity to control the active joint brace. The six remaining subjects each underwent 18 hrs of exercise training using the device for a period of 6 wks. Outcome measures included the upper-extremity component of the Fugl-Meyer scale and the modified Ashworth scale of muscle hypertonicity.

RESULTS

Analysis revealed that the mean upper-extremity component of the Fugl-Meyer scale increased from 15.5 (SD 3.88) to 19 (SD 3.95) (P = 0.04) at the conclusion of training for the six subjects who completed training. Combined (summated) modified Ashworth scale for the elbow flexors and extensors improved from 4.67 (+/-1.2 SD) to 2.33 (+/-0.653 SD) (P = 0.009) and improved for the entire upper limb as well. All subjects tolerated the device, and no complications occurred.

CONCLUSION

EMG-controlled powered elbow orthoses can be successfully controlled by severely impaired hemiparetic stroke survivors. This technique shows promise as a new modality for assisted exercise training after stroke.

Design strategies to improve patient motivation during robot-aided rehabilitation

Background

Motivation is an important factor in rehabilitation and frequently used as a determinant of rehabilitation outcome. Several factors can influence patient motivation and so improve exercise adherence. This paper presents the design of two robot devices for use in the rehabilitation of upper limb movements, that can motivate patients during the execution of the assigned motor tasks by enhancing the gaming aspects of rehabilitation. In addition, a regular review of the obtained performance can reinforce in patients' minds the importance of exercising and encourage them to continue, so improving their motivation and consequently adherence to the program. In view of this, we also developed an evaluation metric that could characterize the rate of improvement and quantify the changes in the obtained performance.

Methods

Two groups (G1, n = 8 and G2, n = 12) of patients with chronic stroke were enrolled in a 3-week rehabilitation program including standard physical therapy (45 min. daily) plus treatment by means of robot devices (40 min., twice daily) respectively for wrist (G1) and elbow-shoulder movements (G2). Both groups were evaluated by means of standard clinical assessment scales and the new robot measured evaluation metric. Patients' motivation was assessed in 9/12 G2 patients by means of the Intrinsic Motivation Inventory (IMI) questionnaire.

Results

Both groups reduced their motor deficit and showed a significant improvement in clinical scales and the robot measured parameters. The IMI assessed in G2 patients showed high scores for interest, usefulness and importance subscales and low values for tension and pain subscales.

Conclusion

Thanks to the design features of the two robot devices the therapist could easily adapt training to the individual by selecting different difficulty levels of the motor task tailored to each patient's disability. The gaming aspects incorporated in the two rehabilitation robots helped maintain patients' interest high during execution of the assigned tasks by providing feedback on performance. The evaluation metric gave a precise measure of patients' performance and thus provides a tool to help therapists promote patient motivation and hence adherence to the training program.