Alma S. Merians

Virtual reality-enhanced stroke rehabilitation

A personal computer (PC)-based desktop virtual reality (VR) system was developed for rehabilitating hand function in stroke patients. The system uses two input devices, a CyberGlove and a Rutgers Master II-ND (RMII) force feedback glove, allowing user interaction with a virtual environment. This consists of four rehabilitation routines, each designed to exercise one specific parameter of hand movement: range, speed, fractionation or strength. The use of performance-based target levels is designed to increase patient motivation and individualize exercise difficulty to a patients current state. Pilot clinical trials have been performed using the above system combined with noncomputer tasks, such as pegboard insertion or tracing of 2D patterns. Three chronic stroke patients used this rehabilitation protocol daily for two weeks. Objective measurements showed that each patient showed improvement on most of the hand parameters over the course of the training. Subjective evaluation by the patients was also positive. This technical report focuses on this newly developed technology for VR rehabilitation.

Motor learning after unilateral brain damage.

Forty adults, post-stroke from anterior circulation unilateral cerebrovascular accident (approximately 2 years post onset) and 40 age-matched controls (M = 57 years) practiced a rapid, spatially and temporally constrained programmed action under one of two augmented feedback practice conditions. Participants in the stroke group used the upper limb ipsilateral to the lesion. After an extended practice period (198 trials), acquisition, retention, and reacquisition performance was assessed for accuracy and consistency and compared over trials, between groups and feedback conditions. Both stroke and control groups demonstrated significant improvement in accuracy and consistency over practice with relative persistence of these changes during retention. There were no differences between groups (stroke vs control) in performance patterns across trials for acquisition, retention, or reacquisition phases. In addition, there were no differential effects of the two augmented feedback conditions on performance and no interactions of feedback condition with group. However, independent of feedback condition, the stroke group performed with more error than did the control group during all experimental phases (i.e., acquisition, retention, reacquisition). These results suggest that unilateral stroke-related damage in the sensorimotor areas primarily effects the processes underlying the control and execution of motor skills but not the learning of those skills. Implications of these findings for physical rehabilitation are discussed.

Sensorimotor training in virtual reality: A review

Recent experimental evidence suggests that rapid advancement of virtual reality (VR) technologies has great potential for the development of novel strategies for sensorimotor training in neurorehabilitation. We discuss what the adaptive and engaging virtual environments can provide for massive and intensive sensorimotor stimulation needed to induce brain reorganization.Second, discrepancies between the veridical and virtual feedback can be introduced in VR to facilitate activation of targeted brain networks, which in turn can potentially speed up the recovery process. Here we review the existing experimental evidence regarding the beneficial effects of training in virtual environments on the recovery of function in the areas of gait,upper extremity function and balance, in various patient populations. We also discuss possible mechanisms underlying these effects. We feel that future research in the area of virtual rehabilitation should follow several important paths. Imaging studies to evaluate the effects of sensory manipulation on brain activation patterns and the effect of various training parameters on long term changes in brain function are needed to guide future clinical inquiry. Larger clinical studies are also needed to establish the efficacy of sensorimotor rehabilitation using VR in various clinical populations and most importantly, to identify VR training parameters that are associated with optimal transfer to real-world functional improvements.

Sensorimotor Training in a Virtual Reality Environment: Does It Improve Functional Recovery Poststroke?

Objective. To investigate the effectiveness of computerized virtual reality (VR) training of the hemiparetic hand of patients poststroke using a system that provides repetitive motor reeducation and skill reacquisition. Methods. Eight subjects in the chronic phase poststroke participated in a 3-week program using their hemiparetic hand in a series of interactive computer games for 13 days of training, weekend breaks, and pretests and posttests. Each subject trained for about 2 to 2.5 h per day. Outcome measures consisted of changes in the computerized measures of thumb and finger range of motion, thumb and finger velocity, fractionation (the ability to move fingers independently), thumb and finger strength, the Jebsen Test of Hand Function, and a Kinematic reach to grasp test. Results. Subjects as a group improved in fractionation of the fingers, thumb and finger range of motion, and thumb and finger speed, retaining those gains at the 1-week retention test. Transfer of these improvements was demonstrated through changes in the Jebsen Test of Hand Function and a decrease after the therapy in the overall time from hand peak velocity to the moment when an object was lifted from the table. Conclusions. It is difficult in current service delivery models to provide the intensity of practice that appears to be needed to effect neural reorganization and functional changes poststroke. Computerized exercise systems may be a way to maximize both the patients’ and the clinicians’ time. The data in this study add support to the proposal to explore novel technologies for incorporation into current practice.

A virtual reality-based exercise system for hand rehabilitation post-stroke

This paper presents preliminary results from a virtual reality (VR)-based system for hand rehabilitation that uses a CyberGlove and a Rutgers Master II-ND haptic glove. This computerized system trains finger range of motion, finger flexion speed, independence of finger motion, and finger strength using specific VR simulation exercises. A remote Web-based monitoring station was developed to allow telerehabilitation interventions. The remote therapist observes simplified versions of the patient exercises that are updated in real time. Patient data is stored transparently in an Oracle database, which is also Web accessible through a portal GUI. Thus the remote therapist or attending physician can graph exercise outcomes and thus evaluate patient outcomes at a distance. Data from the VR simulations is complemented by clinical measurements of hand function and strength. Eight chronic post-stroke subjects participated in a pilot study of the above system. In keeping with variability in both their lesion size and site and in their initial upper extremity function, each subject showed improvement on a unique combination of movement parameters in VR training. Importantly, these improvements transferred to gains on clinical tests, as well as to significant reductions in task-completion times for the prehension of real objects. These results are indicative of the potential feasibility of this exercise system for rehabilitation in patients with hand dysfunction resulting from neurological impairment.

Low-cost Virtual Rehabilitation of the Hand for Patients Post-Stroke

We are witnessing the convergence of game technology (both software and hardware) with rehabilitation science to form a second-generation virtual rehabilitation framework. This is fortunate in view of the need to reduce system costs and thus facilitate adoption in clinical practice. This paper presents an Xbox-based physical rehabilitation system currently under development at Rutgers University. Unlike its high-end precursor aimed at hand training for patients post-stroke, the experimental system described here uses an inexpensive P5 game glove and Java 3D simulations. This results in significant cost savings, albeit with some tradeoff in functionality

Design of a complex virtual reality simulation to train finger motion for persons with hemiparesis: a proof of concept study.

BackgroundCurrent neuroscience has identified rehabilitation approaches with the potential to stimulate adaptive changes in the brains of persons with hemiparesis. These approaches include, intensive task-oriented training, bimanual activities and balancing proximal and distal upper extremity interventions to reduce competition between these segments for neural territory.MethodsThis paper describes the design and feasibility testing of a robotic/virtual environment system designed to train the hand and arm of persons with hemiparesis. The system employs a simulated piano that presents visual, auditory and tactile feedback comparable to an actual piano. Arm tracking allows patients to train both the arm and hand as a coordinated unit, emphasizing the integration of both transport and manipulation phases. The piano trainer includes songs and scales that can be performed with one or both hands. Adaptable haptic assistance is available for more involved subjects. An algorithm adjusts task difficulty in proportion to subject performance. A proof of concept study was performed on four subjects with upper extremity hemiparesis secondary to chronic stroke to establish: a) the safety and feasibility of this system and b) the concurrent validity of robotically measured kinematic and performance measures to behavioral measures of upper extremity function.ResultsNone of the subjects experienced adverse events or responses during or after training. As a group, the subjects improved in both performance time and key press accuracy. Three of the four subjects demonstrated improvements in fractionation, the ability to move each finger individually. Two subjects improved their aggregate time on the Jebsen Test of Hand Function and three of the four subjects improved in Wolf Motor Function Test aggregate time.ConclusionThe system designed in this paper has proven to be safe and feasible for the training of hand function for persons with hemiparesis. It features a flexible design that allows for the use and further study of adjustments in point of view, bilateral and unimanual treatment modes, adaptive training algorithms and haptically rendered collisions in the context of rehabilitation of the hemiparetic hand.

The Rutgers Arm, a rehabilitation system in virtual reality: a pilot study.

Stroke is one of the leading causes of death and disability worldwide. Its prevalence calls for innovative rehabilitation methods. The Rutgers Arm is a novel upper extremity rehabilitation system consisting of a low-friction table, three-dimensional (3D) tracker, custom forearm support, PC workstation, library of Java 3D virtual reality (VR) exercises, clinical database module, and a tele-rehabilitation extension. The system was tested on a chronic stroke subject, under local and tele-rehabilitation conditions, over 5 weeks of training. Results show improvements in arm motor control and shoulder range of motion, corresponding to improved Fugl-Meyer test scores. Exercise duration, level of difficulty, and patient motivation were maintained under tele-rehabilitaion. A 1-week retention trial showed that gains were maintained.

Incorporating Haptic Effects Into Three-Dimensional Virtual Environments to Train the Hemiparetic Upper Extremity

Current neuroscience has identified several constructs to increase the effectiveness of upper extremity rehabilitation. One is the use of progressive, skill acquisition-oriented training. Another approach emphasizes the use of bilateral activities. Building on these principles, this paper describes the design and feasibility testing of a robotic/virtual environment system designed to train the arm of persons who have had strokes. The system provides a variety of assistance modes, scalable workspaces and hand-robot interfaces allowing persons with strokes to train multiple joints in three dimensions. The simulations utilize assistance algorithms that adjust task difficulty both online and offline in relation to subject performance. Several distinctive haptic effects have been incorporated into the simulations. An adaptive master-slave relationship between the unimpaired and impaired arm encourages active movement of the subjects hemiparetic arm during a bimanual task. Adaptive anti-gravity support and damping stabilize the arm during virtual reaching and placement tasks. An adaptive virtual spring provides assistance to complete the movement if the subject is unable to complete the task in time. Finally, haptically rendered virtual objects help to shape the movement trajectory during a virtual placement task. A proof of concept study demonstrated this system to be safe, feasible and worthy of further study.

A virtual reality based exercise system for hand rehabilitation post-stroke: transfer to function

We present preliminary results from a virtual reality (VR)-based system for hand rehabilitation that uses a CyberGlove and a Rutgers Master II-ND haptic glove. This system trains finger range of motion, finger flexion speed, independence of finger motion and finger strength. Eight chronic post-stroke subjects participated. In keeping with variability in both the lesion site and in initial upper extremity function, each subject showed improvement on a unique combination of movement parameters in VR training. These improvements transferred to gains on clinical tests, as well as to significant reductions in task completion times for the prehension of real objects. These results are indicative of the potential feasibility of this exercise system for rehabilitation in patients with hand dysfunction resulting from neurological impairment.