An investigation of effects of the partial active assistance in a virtual environment based rehabilitation system

This thesis describes a study on a new active assistance in robotic rehabilitation in a haptic virtual environment for post-stroke patients. The novelty of this active assistance system lies in that the assistance is directly rendered on the result of a task performing. Active assistance will generally raise the confidence level of patients in performing a rehabilitation exercise. However, an overly high assistance level may induce cognitive fatigue with patients and thus decreases their motivation of performing a rehabilitation exercise. This thesis hypothesizes that a proper active assistance can improve the performance of a rehabilitation exercise, but will not reduce the motivation of patients in doing rehabilitation exercise. However, due to the difficulty in obtaining a proper number of patients for the experiment, the study turned to healthy people. Accordingly, a revised hypothesis is that active assistance on healthy people does not improve the task performance and not reduces the motivation of healthy people. In this thesis, first, a test-bed with the haptic virtual environment was designed and constructed. The test-bed included a simple task – i.e., following a predefined circle trajectory. Then, a statistical experiment was designed and an experiment was conducted on the test-bed. The experimental results test the hypothesis successfully. The main contributions of this thesis are: (1) the development of a new active assistance system for rehabilitation in a virtual environment and (2) the experimental study on the motivation of healthy people with the developed active assistance system. A care must, however, be taken that the experiment was conducted on healthy people and the conclusion drawn from the study may not be valid on patients

Upper extremity rehabilitation using interactive virtual environments

Stroke affects more than 700,000 people annually in the U.S. It is the leading cause of major disability. Recovery of upper extremity function remains particularly resistant to intervention, with 80% to 95% of persons demonstrating residual upper extremity impairments lasting beyond six months after the stroke. The NJIT Robot Assistive Virtual Rehabilitation (NJIT-RAVR) system has been developed to study optimal strategies for rehabilitation of arm and hand function. Several commercial available devices, such as HapticMaster™, Cyberglove™, trakSTAR™ and Cybergrasp™, have been integrated and 11 simulations were developed to allow users to interact with virtual environments. Visual interfaces used in these simulations were programmed either in Virtools or in C++ using the Open GL library. Stereoscopic glasses were used to enhance depth perception and to present movement targets to the subjects in a 3-dimensional stereo working space. Adaptive online and offline algorithms were developed that provided appropriate task difficulty to optimize the outcomes. A pilot study was done on four stroke patients and two children with cerebral palsy to demonstrate the usability of this robot-assisted VR system. The RAVR system performed well without unexpected glitches during two weeks of training. No subjects experienced side effects such as dizziness, nausea or disorientation while interacting with the virtual environment. Each subject was able to finish the training, either with or without robotic adaptive assistance. To investigate optimal therapeutic approaches, forty stroke subjects were randomly assigned to two groups: Hand and Arm training Together (HAT) and Hand and Arm training Separately (HAS). Each group was trained in similar virtual reality training environments for three hours a day, four days a week for two weeks. In addition, twelve stroke subjects participated as a control group. They received conventional rehabilitation training of similar intensity and duration as the HAS and HAT groups. Clinical outcome measurements included the Jebsen Test of Hand Function, the Wolf Motor Function Test, and the ReachGrasp test. Secondary outcome measurements were calculated from kinematic and kinetic data collected during training in real time at 100 Hz. Both HAS and HAT groups showed significant improvement in clinical and kinematic outcome measurements. Clinical improvement compared favorably to the randomized clinical trials reported in the literature. However, there was no significant improvement difference between the two groups. Subjects from the control group improved in clinical measurements and in the ReachGrasp test. Compared to the control group, the ReachGrasp test showed a larger increase in movement speed during reaching and in the efficiency of lifting an object from the table in the combined HAS and HAT group. The NJIT-RAVR system was further modified to address the needs of children with hemiplegia due to Cerebral Palsy. Thirteen children with cerebral palsy participated in the total of nine sessions of one hour training that lasted for three weeks. Nine of the children were trained using the RAVR system alone, and another four had training with the combined Constraint-Induced Movement therapy and RAVR therapy. As a group, the children demonstrated improved performance across measurements of the Arm Range of Motion (AROM), motor function, kinematics and motor control. While subjects\u27 responses to the games varied, they performed each simulation while maintaining attention sufficient to improve in both robotic task performance and in measures of motor function

Diseño de entornos de realidad virtual aplicables a sistemas de robótica asistencial: un análisis literario

Virtual Reality (VR) environments can be applied to assistive robotics to improve the effectiveness and the user experience perception in the rehabilitation process due to its innovative nature, getting to entertain patients while they recover their motor functions. This literature review pretends to analyze some design principles of VR environments developed for upper limb rehabilitation processes. The idea is to identify features related to peripheral and central nervous systems, types of information included as feedback to increase the user's levels of immersion having a positive impact on the user's performance and experience during the treatment. A total of 32 articles published in Scopus, IEEE, PubMed, and Web of Science in the last four years were reviewed. We present the article selection process, the division by concepts presented previously, and the guidelines that can be considered for the design of VR environments applicable to assistive robots for upper limbs rehabilitation processes.Los entornos de Realidad Virtual (RV) aplicables a sistemas de robótica asistencial pueden ser diseñados de manera que mejoren la efectividad y la experiencia de usuario de los procesos de rehabilitación debido a su naturaleza novedosa, logrando entretener a los pacientes mientras recuperan sus funciones motoras. Esta revisión literaria pretende analizar los criterios de diseño de entornos de RV utilizados en procesos de rehabilitación de miembro superior, identificando las características de entornos para rehabilitación de problemas asociados el sistema nervioso central y periféricos, los tipos de información que se realimenta al usuario para beneficiar los niveles de inmersión y su impacto en términos del desempeño y la experiencia del usuario en tratamiento. Un total de 32 artículos publicados en revistas indexadas de Scopus, IEEE, PubMed y Web of Science en los últimos cuatro años fueron revisados. Se presenta el proceso de selección de artículos, la división por las temáticas presentadas anteriormente y los lineamientos generales que pueden ser considerados para el diseño de entornos de RV aplicables a robots asistenciales en procesos de rehabilitación de miembro superior

Assessment of a hand exoskeleton on proximal and distal training in virtual environments for robot mediated upper extremity rehabilitation

Stroke is the leading cause of disability in the United States with approximately 800,000 cases per year. This cerebral vascular accident results in neurological impairments that reduce limb function and limit the daily independence of the individual. Evidence suggests that therapeutic interventions with repetitive motor training can aid in functional recovery of the paretic limb. Robotic rehabilitation may present an exercise intervention that can improve training and induce motor plasticity in individuals with stroke. An active (motorized) hand exoskeleton that provides support for wrist flexion/extension, abduction/adduction, pronation/supination, and finger pinch is integrated with a pre-existing 3-Degree of Freedom (DOF) haptic robot (Haptic Master, FCS Moog) to determine the efficacy of increased DOF during proximal and distal training in Upper Extremity (UE) rehabilitation. Subjects are randomly assigned into four groups to evaluate the significance of increased DOF during virtual training: Haptic Master control group (HM), Haptic Master with Gripper (HMG), Haptic Master with Wrist (HMW), and Haptic Master with Gripper and Wrist (HMWG). Each subject group performs a Pick and Place Task in a virtual environment where the distal hand exoskeleton is mapped to the virtual representation of the hand. Subjects are instructed to transport as many virtual cubes as possible to a specified target in the allotted time period of 120s. Three cube sizes are assessed to determine efficacy of the assistive end-effector. An additional virtual task, Mailbox Task, is performed to determine the effect of training and the ability to transfer skills between virtual settings in an unfamiliar environment. The effects of viewing mediums are also investigated to determine the effect of immersion on performance using an Oculus Rift as an HMD compared to conventional projection displays. It is hypothesized that individuals with both proximal and complete distal hand control (HMWG) will see increased benefit during the Pick and Place Task than individuals without the complete distal attachment, as assisted daily living tasks are often accomplished with coordinated arm and hand movement. The purpose of this study is to investigate the additive effect of increased degrees of freedom at the hand through task-specific training of the upper arm in a virtual environment, validate the ability to transfer skills obtained in a virtual environment to an untrained task, and determine the effects of viewing mediums on performance. A feasibility study is conducted in individuals with stroke to determine if the modular gripper can assist pinch movements. These investigations represent a comprehensive investigation to assess the potential benefits of assistive devices in a virtual reality setting to retrain lost function and increase efficacy in motor control in populations with motor impairments

Effects of sensory cueing in virtual motor rehabilitation. A review.

Objectives To critically identify studies that evaluate the effects of cueing in virtual motor rehabilitation in patients having different neurological disorders and to make recommendations for future studies. Methods Data from MEDLINE®, IEEExplore, Science Direct, Cochrane library and Web of Science was searched until February 2015. We included studies that investigate the effects of cueing in virtual motor rehabilitation related to interventions for upper or lower extremities using auditory, visual, and tactile cues on motor performance in non-immersive, semi-immersive, or fully immersive virtual environments. These studies compared virtual cueing with an alternative or no intervention. Results Ten studies with a total number of 153 patients were included in the review. All of them refer to the impact of cueing in virtual motor rehabilitation, regardless of the pathological condition. After selecting the articles, the following variables were extracted: year of publication, sample size, study design, type of cueing, intervention procedures, outcome measures, and main findings. The outcome evaluation was done at baseline and end of the treatment in most of the studies. All of studies except one showed improvements in some or all outcomes after intervention, or, in some cases, in favor of the virtual rehabilitation group compared to the control group. Conclusions Virtual cueing seems to be a promising approach to improve motor learning, providing a channel for non-pharmacological therapeutic intervention in different neurological disorders. However, further studies using larger and more homogeneous groups of patients are required to confirm these findings

User-Centered Design and Evaluation of an Upper Limb Rehabilitation System with a Virtual Environment

Virtual environments (VEs) and haptic devices increase patients’ motivation. Furthermore, they observe their performance during rehabilitation. However, some of these technologies present disadvantages because they do not consider therapists’ needs and experience. This research presents the development and usability evaluation of an upper limb rehabilitation system based on a user-centered design approach for patients with moderate or mild stroke that can perform active rehabilitation. The system consists of a virtual environment with four virtual scenarios and a developed haptic device with vibrotactile feedback, and it can be visualized using a monitor or a Head-Mounted Display (HMD). Two evaluations were carried out; in the first one, five therapists evaluated the system’s usability using a monitor through the System Usability Scale, the user experience with the AttrakDiff questionnaire, and the functionality with customized items. As a result of these tests, improvements were made to the system. The second evaluation was carried out by ten volunteers who evaluated the usability, user experience, and performance with a monitor and HMD. A comparison of the therapist and volunteer scores has shown an increase in the usability evaluation (from 78 to >85), the hedonic score rose from 0.6 to 2.23, the pragmatic qualities from 1.25 to 2.20, and the attractiveness from 1.3 to 2.95. Additionally, the haptic device and the VE showed no relevant difference between their performance when using a monitor or HMD. The results show that the proposed system has the characteristics to be a helpful tool for therapists and upper limb rehabilitation

Review of control strategies for robotic movement training after neurologic injury

There is increasing interest in using robotic devices to assist in movement training following neurologic injuries such as stroke and spinal cord injury. This paper reviews control strategies for robotic therapy devices. Several categories of strategies have been proposed, including, assistive, challenge-based, haptic simulation, and coaching. The greatest amount of work has been done on developing assistive strategies, and thus the majority of this review summarizes techniques for implementing assistive strategies, including impedance-, counterbalance-, and EMG- based controllers, as well as adaptive controllers that modify control parameters based on ongoing participant performance. Clinical evidence regarding the relative effectiveness of different types of robotic therapy controllers is limited, but there is initial evidence that some control strategies are more effective than others. It is also now apparent there may be mechanisms by which some robotic control approaches might actually decrease the recovery possible with comparable, non-robotic forms of training. In future research, there is a need for head-to-head comparison of control algorithms in randomized, controlled clinical trials, and for improved models of human motor recovery to provide a more rational framework for designing robotic therapy control strategies

Interactive Haptics for Remote and On-Site Assessment of Arm Function Following a Stroke

There is a great need to improve the rehabilitation and assessment of arm and hand function of stroke survivors in the home due to cost, time and availability of healthcare professionals. Robotics and haptic technologies can be used to improve and facilitate rehabilitation and assessment in the home. The primary goal of this thesis was to explore the feasibility of using lightweight, low-cost haptic devices for remote home-based rehabilitation. The strategy that this thesis followed was to develop tools, perform unit testing, and finally assess feasibility with target users in a series of case studies. The thesis started by developing an assessment tool, specifically the Nine Hole Peg Test (NHPT), and investigated how haptic devices can be used to enhance the data collection for this task to garner more information regarding the level of manual dexterity a stroke survivor has in their impaired limb. The next study investigated collaboration in haptic environments and how the findings from a collaborative haptic experiment could be used to influence task design for future experiments with haptic environments. The final study assessed the feasibility of a home-based assessment and rehabilitation system with elements of telerehabilitation and remote collaboration and interaction providing four complete case studies from stroke survivors. In summary, our findings showed that by combining physical apparatus with a virtual world, less variable results are observed than in purely virtual haptic tasks. We also showed that interaction techniques in collaborative haptic environments change depending on the shape of the objects in the virtual task – this information can be used to influence task design to target specific motor deficits when using the device for exercise. Finally, the home-based study showed the feasibility of using the experimental rig at home and provided improvement measures that matched the perceived benefits to arm function that the participants described on completing the trial