Jeffrey A. Lewis

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.

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.

Technical and Patient Performance Using a Virtual Reality-Integrated Telerehabilitation System: Preliminary Finding

Telerehabilitation is the provision of rehabilitation services at a distance by a therapist at a remote location. Integration with virtual reality (VR) is a relatively new addition to this field. This paper describes the technical and patient performance of a telerehabilitation application the remote console (ReCon) that is integrated with a VR system. The VR system consists of the Rutgers Ankle prototype robot, a local PC which is connected with a remote PC connected over the Internet. Six individuals in the chronic phase poststroke participated in a four week training program. They used the robot to interact with two VR simulations, while the therapist was in the same room during the first three weeks or in another room during the fourth week. Technical and patient performance was assessed in the transition from the third to the fourth week of training. Technical performance of the system was assessed based on bandwidth and lag of message transmission, which were found to be suitable for clinic-to-clinic communication. Patient performance (in terms of accuracy of ankle movement, exercise duration and training efficiency, mechanical power of the ankle, and number of repetitions) did not decrease during telerehabilitation in the fourth week. These preliminary findings over a short telerehabilitation intervention support the feasibility of remote monitoring of VR-based telerehabilitation without adverse effects on patient performance

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.

FMRI analysis of neural mechanisms underlying rehabilitation in virtual reality: activating secondary motor areas.

A pilot functional MRI study on a control subject investigated the possibility of inducing increased neural activations in primary, as well as secondary motor areas through virtual reality-based exercises of the hand. These areas are known to be important in effective motor output in stroke patients with impaired corticospinal systems. We found increased activations in these brain areas during hand exercises in VR when compared to vision of non-anthropomorphic shapes. Further studies are needed to investigate the potential of virtual reality-based rehabilitation for tapping into the properties of the mirror neuron system to stimulate plasticity in sensorimotor areas

VRACK — virtual reality augmented cycling kit: Design and validation

In this paper the virtual reality augmented cycling kit (VRACK) a mechatronic rehabilitation system with an interactive virtual environment is presented. It was designed as a modular system that can convert most bicycles in virtual reality (VR) cycles. Novel hardware components embedded with sensors were implemented on a stationary exercise bicycle to monitor physiological and biomechanical parameters of participants while immersing them in a virtual reality simulation providing the user with visual, auditory and haptic feedback. This modular and adaptable system attaches to commercially-available stationary bicycle systems and interfaces with a personal computer for simulation and data acquisition processes. The bicycle system includes novel handle bars based on hydraulic pressure sensors and innovative pedals that monitor lower extremity kinetics and kinematics. Parameters monitored by these systems are communicated to a practitioners interface screen and can be amplified before entering its virtual environment. The first prototype of the system was successful in demonstrating that a modular mechatronic kit can monitor and record kinetic, kinematic and physiologic parameters of riders.

Formative evaluation and preliminary findings of a virtual reality telerehabilitation system for the lower extremity

Usability studies are an essential and iterative component of technology development and ease its transfer from the laboratory to the clinic. Although such studies are standard methodology in todays graphical user-interface applications, it is not clear that current methods apply to new technologies such as virtual reality. Thus experimentation is needed to examine what existing methods can be viably transferred to the new user-interaction situations. In this paper, 5 integrated interfaces with 3 simultaneous users are evaluated via a set of usability studies, which adapt traditional methods for assessing the ease of use of the interface design. A single expert domain user was run in an intensive study that examined the therapist manual and interfaces of the Rutgers Ankle Rehabilitation System (RARS). The interface and manual were extensively modified based on this evaluation. A second study involving 5 therapists was then conducted to evaluate the telerehabilitation component of the RARS system. In both studies, the tester and developers observations, along with the session videotapes and therapist-user questionnaires, were triangulated to identify user problems and suggest design changes expected to increase the usability of the system. Changes that resulted from the analysis with the domain expert are described and recommendations for how to conduct usability studies in such multiuser remote virtual reality situations are proposed. Results from the pilot usability telemonitoring studies are also presented. The validity of usability studies in the development and refinement of rehabilitation technology is highlighted.

Virtual Reality-Integrated Telerehabilitation System: Patient and Technical Performance

Telerehabilitation is the provision of rehabilitation services at a distance, by a therapist at a remote location. Telerehabilitation, integrated with virtual reality, is a relatively new addition to this field. This paper describes the technical and patient performance of a virtual reality based telerehabilitation system for ankle training. Telerehabilitation was introduced in the fourth week of a lower extremity virtual reality-based training program for individuals post-stroke. Technical performance of the system was assessed based on bandwidth and time lag of message transmission, which were found to be suitable for clinic-to-clinic communication. Patient performance in the transition from the third to the fourth week of training remained the same (for accuracy of ankle movement, exercise duration and training efficiency) or increased (mechanical power of the ankle and number of repetitions). These findings strengthen the case for virtual reality based telerehabilitation

Feasibility of virtual reality augmented cycling for health promotion of people poststroke.

Background and Purpose: A virtual reality (VR) augmented cycling kit (VRACK) was developed to address motor control and fitness deficits of individuals with chronic stroke. In this article, we report on the safety, feasibility, and efficacy of using the VR augmented cycling kit to improve cardiorespiratory (CR) fitness of individuals in the chronic phase poststroke. Methods: Four individuals with chronic stroke (47–65 years old and ≥3 years poststroke), with residual lower extremity impairments (Fugl-Meyer 24–26/34), who were limited community ambulators (gait speed range 0.56–1.1 m/s) participated in this study. Safety was defined as the absence of adverse events. Feasibility was measured using attendance, total exercise time, and “involvement” measured with the presence questionnaire (PQ). Efficacy of CR fitness was evaluated using a submaximal bicycle ergometer test before and after an 8-week training program. Results: The intervention was safe and feasible with participants having 1 adverse event, 100% adherence, achieving between 90 and 125 minutes of cycling each week, and a mean PQ score of 39 (SD 3.3). There was a statistically significant (13%; P = 0.035) improvement in peak VO2, with a range of 6% to 24.5%. Discussion and Conclusion: For these individuals, poststroke, VR augmented cycling, using their heart rate to set their avatars speed, fostered training of sufficient duration and intensity to promote CR fitness. In addition, there was a transfer of training from the bicycle to walking endurance. VR augmented cycling may be an addition to the therapists tools for concurrent training of mobility and health promotion of individuals poststroke. Video Abstract available (see Video, Supplemental Digital Content 1, http://links.lww.com/JNPT/A53) for more insights from the authors.

Modular mechatronic system for stationary bicycles interfaced with virtual environment for rehabilitation.

BackgroundCycling has been used in the rehabilitation of individuals with both chronic and post-surgical conditions. Among the challenges with implementing bicycling for rehabilitation is the recruitment of both extremities, in particular when one is weaker or less coordinated. Feedback embedded in virtual reality (VR) augmented cycling may serve to address the requirement for efficacious cycling; specifically recruitment of both extremities and exercising at a high intensity.MethodsIn this paper a mechatronic rehabilitation bicycling system with an interactive virtual environment, called Virtual Reality Augmented Cycling Kit (VRACK), is presented. Novel hardware components embedded with sensors were implemented on a stationary exercise bicycle to monitor physiological and biomechanical parameters of participants while immersing them in an augmented reality simulation providing the user with visual, auditory and haptic feedback. This modular and adaptable system attaches to commercially-available stationary bicycle systems and interfaces with a personal computer for simulation and data acquisition processes. The complete bicycle system includes: a) handle bars based on hydraulic pressure sensors; b) pedals that monitor pedal kinematics with an inertial measurement unit (IMU) and forces on the pedals while providing vibratory feedback; c) off the shelf electronics to monitor heart rate and d) customized software for rehabilitation. Bench testing for the handle and pedal systems is presented for calibration of the sensors detecting force and angle.ResultsThe modular mechatronic kit for exercise bicycles was tested in bench testing and human tests. Bench tests performed on the sensorized handle bars and the instrumented pedals validated the measurement accuracy of these components. Rider tests with the VRACK system focused on the pedal system and successfully monitored kinetic and kinematic parameters of the rider’s lower extremities.ConclusionsThe VRACK system, a virtual reality mechatronic bicycle rehabilitation modular system was designed to convert most bicycles in virtual reality (VR) cycles. Preliminary testing of the augmented reality bicycle system was successful in demonstrating that a modular mechatronic kit can monitor and record kinetic and kinematic parameters of several riders.