Table 2.
Characteristics of included studies ordered by pathology most investigated.
| Reference | Pathology involved (rehabilitation focus) | Devices (name) | VR environment | Main outcomes |
|---|---|---|---|---|
| Assis et al29 | Stroke (upper limbs) | Webcam love rojection screen (NeuroR system) |
Two visual tracking approaches for NeuroR system were developed. (1) Participants wore a glove on the injured arm and physical markers were adjusted to each participant’s shoulder. (2) The computer system identified the injured arm and tracked it without the glove (markerless tracking). In both cases, the participants are not facing the screen displaying the injured arm wearing the glove. Instead, they see a virtual 3-dimensional arm replacing the actual limb on the screen | NeuroR system provides a mental practice method combined with visual feedback for motor rehabilitation of chronic stroke patients, giving the illusion of injured upper-limb (UL) movements while the affected UL is resting. Its application is feasible and safe. This system can be used to improve UL rehabilitation, an additional treatment past the traditional period of the stroke patient hospitalization and rehabilitation |
| Calabro et al30 | Stroke (lower limbs) | Lokomat 42-in flat screen Dolby surround system (—) |
The 2D VR presented visual feedback showing a VR run game where the patient had to collect or avoid objects, to motivate himor her to walk actively The Lokomat device served as a multimodal feedback system: the human-machine interaction forces measured from the Lokomat device were used as an input device for the patient’s movements into the VR |
The robotic-based rehabilitation combined with VR in patients with chronic hemiparesis induced an improvement in gait and balance. EEG data suggest that the use of VR may entrain several brain areas (probably encompassing the mirror neuron system) involved in motor planning and learning, thus leading to an enhanced motor performance |
| Held et al31 | Stroke (posture rehabilitation) | Force plate 3D camera Kinect TV screen (REWIRE autonomous telerehabilitation platform) |
Exergames where the patient sees himself as an avatar moving and interacting in real time with the virtual game environment | Autonomous telerehabilitation for balance and gait training with the REWIRE system is safe, feasible and can help to intensive rehabilitative therapy at home |
| Mousavi Hondori et al32 | Stroke (cognitive and motor rehabilitation) | Small plastic cup with color marker Overhead camera LifeCam (—) |
A version of Fruit Ninja video game. A fruit target would then appear in 1 of the 4 corners of the tabletop and start moving around the desktop workspace. The subject was to use the stroke-affected hand to move the cursor onto the fruit (which would slice the fruit in half, make a noise, and score 1 point) before the fruit disappeared (which would score 0 points). Once the fruit was sliced, or disappeared, or unsliced, a new fruit target would appear in 1 of the 4 corners, the sequence of which was pseudo-randomized. Subjects were instructed to slice as many fruits as possible within the allotted time. The score was presented throughout each game. One round of each game was 90 seconds long. | The optimal choice of human-computer interface likely varies across individuals, over time, and according to specific goals. This study provides insights into how choice of human-computer interface affects motor performance and thus might influence stroke rehabilitation and motor recovery |
| House et al33 | Stroke (cognitive and bimanual upper extremity rehabilitation) | A low-friction symmetrical table that was wheelchair accessible and electrically lifted or lowered to accommodate different body types. (BrightArm Duo system) | BrightArm Duo simulations allow to adapt to each participant each day. The adaptation was based on arm reach and grasp strength baselines performed at the start of each rehabilitation session. Each of the custom games had some settings that required reach and grasp dual tasking | The results showed clinical benefits in the motor, emotive, and cognitive domains, as well as good technology acceptance by the participants. There was a large impact on attention/working memory following training on the BrightArm Duo system |
| Lin et al34 | Stroke (fine motor impairment in finger movement) | Vibration-assisted glove (—) |
The virtual environment consisted of 2 games. Gopher hitting game: 4 individual gopher-like cartoon characters correspond to the 4 fingers of a patient and randomly appear in a virtual environment. When a gopher appears on the computer screen, the vibration motor stimulates the assigned finger inducing the patient to use that particular finger to hit a designated click region on the table. Musical note hitting game: the musical note hitting game with balls in 4 regions. To enable patients who are familiar with musical instruments to play this game and receive effective therapeutic evaluation, a random and nonrepeating melody consisting of 7 fundamental notes is played through a computer speaker. A ball in a virtual environment is programmed to rise depending on simultaneous vibrotactile and acoustic stimulation. In each trial, the patient presses the tip of the corresponding finger on the correct click region | The preliminary test results of using healthy people elucidated the potential use and benefits of adding vibrotactile stimulation in practical haptic training. Design concerns related to the mechatronic design and clinical trials were presented to enable optimizing the performance of the proposed system. Future studies could apply this system on stroke patients and investigate the rehabilitation performance by following comparative clinical protocols |
| Lledo et al14 | Stroke (upper-limb neurorehabilitation) | Robot system (PUPArm) | The virtual task with the VR environment consists on a roulette formed by a central target and 8 peripheral targets. These targets were circles with a radius of 1 cm. The 8 peripheral targets were distributed uniformly on the circumference of the circle and placed 10 cm from the center target. The main purpose of this task was to reach 1 of the 8 peripheral targets from central target by controlling the robot end-effector attached to the subject’s hand | The hypothesis that consists of showing a visualization environment more natural (3D) increasing the immersion level did not provide many improvements regarding an environment simpler (2D). Using 2D environments in virtual therapy may be a more appropriate and comfortable way to perform tasks for upper limb rehabilitation of poststroke patients, in terms of accuracy to effectuate optimal kinematic trajectories |
| Mobini et al35 | Stroke (upper body joints) | Microsoft Kinect for Xbox 360 Microsoft Kinect’s skeleton tracking (—) |
In the program, they were instructed to move their hands to intercept and catch several approaching balls. All of the targets are on a plane parallel to the frontal plane but reaching them requires movements in the 3D space. The program also provided audio feedback to the patients based on their performance | The results are promising for the development of home-based rehabilitation systems, which can analyze patient’s movements using Kinect as an affordable motion capture sensor |
| da Silva et al36 | Stroke (sensorimotor function) | Nintendo Wii Multimedia projector (—) |
The Tennis and Hula hoop games were applied during the first session; the Soccer and Boxing games were applied during the second session | Virtual rehabilitation using the Nintendo Wii and conventional physical therapy both effectively treat poststroke hemiparetic patients by improving passive movement and pain scores, motor function of the upper limb, balance, physical functioning, vitality, and the physical and emotional aspects of role functioning |
| Saposnik et al37 | Stroke (motor recovery of upper extremity) | Nintendo Wii (—) |
Wii Sports and Game Party 3 | This study suggests that the type of task used in motor rehabilitation poststroke might be less relevant, as long as it is intensive enough and task specific. Simple, low-cost, and widely available recreational activities might be as effective as innovative nonimmersive VR technologies |
| Simkins et al38 | Stroke | Two-armed robot, 14-DOF exoskeleton termed the EXO-UL7 50-in flat screen monitor (—) |
The virtual games were controlled using the joint angles of the robot. Full-arm movements in flower, paint, reach, and handball were generated using a forward kinematic model of the avatar arms. The Pinball game was unique in that the paddles were simply actuated by wrist flexion and extension. The Pong and Circle games used a paddle that was constrained to a linear path | After 12 training sessions (90 minutes/session), the bilateral training group had the greatest intensity of movement training. They also had the greatest improvement in range of motion at the shoulder. The unilateral training group showed the greatest reduction in spasticity |
| Steinisch et al39 | Stroke (neuromotor rehabilitation of upper limbs) | Passive robotic device (Trackhold) 22-in LCD (—) |
The VR training applications (Sponge, Bug Hunt, Grab 2D, Grab 3D) simulate ADLs and/or reproduce simple visuomotor coordination tasks. Subjects interact online with the VR training applications by moving the Trackhold’s end-effector and observe the changes occurring in the virtual environments in real time | Results from kinematic and EEG data analysis are in line with knowledge from currently available literature and theoretical predictions and demonstrate the feasibility and potential usefulness of the proposed rehabilitation system to monitor neuro-motor recovery |
| Thielbar et al40 | Stroke (fine motor control) | Actuated glove PneuGlove (Actuated virtual keypad—AVK system) |
The AVK system combines a custom actuated glove, the PneuGlove, with a virtual scene consisting of a hand and 5 keys. The PneuGlove provides both independent measurement and actuation of each digit. Air pressure controlled through servovalves is used to extend (or prevent flexion of) a specified digit by inflating an air chamber located on the palmar side of the digit. Evacuation of the air chamber permits almost unrestricted movement of the digit | Actively assisted individuation therapy comprised nontask-specific modalities, such as can be achieved with virtual platforms like the AVK described here, may prove to be valuable clinical tools for increasing the effectiveness and efficiency of therapy following stroke. Stroke survivors with chronic impairment were able to successfully use the system to improve hand motor control. Thus, repetitive movement therapy for independent finger movements, such as with AVK system, may be beneficial and warrants further exploration |
| Trombetta et al41 | Stroke (upper limb motor and balance rehabilitation) | HMD Oculus Rift and HTC Vive Kinect for Windows SDK 2.0 Unity game engine to create the game interface Support for stereoscopic visualization Smart TV 3D (Motion Rehab AVE 3D) |
The game contemplates different exercises in a 3D space: flexion, abduction, shoulder adduction, horizontal shoulder adduction and abduction, elbow extension, wrist extension, knee flexion, and hip flexion and abduction. The aim is to simulate 6 activities in which the patient must move his or her hands, upper limbs, lower limbs, and trunk, to get the objects and score. All activities developed for the game contemplates exercises used in conventional physiotherapy sessions | Our evaluation showed that the game could be used as a useful tool to motivate the patients during rehabilitation sessions. All participants classified as an interesting and excellent experience for elderly age. We also suggested to use the game in sessions with poststroke patients, initially, with a most popular visualization device (Smart TV 3D), in third person as the participants felt little bit comfortable during the interaction process Next step is to evaluate its effectiveness for stroke patients, to verify whether the interface and game exercises contribute into the motor rehabilitation treatment progress |
| Verma et al42 | Stroke (lower limbs) | Nintendo Wii Balance board Sacral Belt holding an android phone (VR-based balance training—VBaT platform) |
A database of 30 unique combinations of VR-based environments and virtual objects related to tasks of daily living and entertainment. The task required participants to shift their weight in different directions from the central hold state in the VR environment to a predefined target position, with various target images (chosen randomly from a database) | Results indicate the potential of the VBaT system to cause improvement in overall average task performance over the course of training while using the VBaT. Thus, the VBaT system is proposed to be a step toward an effective balance training platform for people with balance disorder |
| Zoccolillo et al43 | Cerebral palsy (upper limbs) | Xbox with Kinect (—) |
Three games were included into the Kinect Adventures Package. In “Space pops,” the subject is asked to pop bubbles appearing in the virtual environment by touching them. Subject should flap arms for flying around the virtual environment and put arms back down for descending. In “20.000 Leaks,” the child is asked to stop the water from filling the tank by placing a hand, or a foot, or any other body parts over a leak opened on a wall of an underwater glass tank. In “Rally Ball,” balls will shoot down a lane toward the avatar, and the child must hit the balls back with a part of body and destroy targets at the end of the lane. Other 3 games were included into the Kinect Sports Package and were virtual simulation of 3 sports: boxe and volley mainly (but not only) involving bimanual movements, and bowling in which the child was asked to throw the virtual ball toward the pins with the paretic upper limb | Video game–based therapy resulted effective in improving the motor functions of upper limb extremities in children with cerebral palsy, conceivably for the increased quantity of limb movements, but failed in improving the manual abilities for performing activities of daily living which benefited more from conventional therapy |
| Bortone et al44 | Cerebral palsy and developmental dyspraxia (upper limbs) | HMD Oculus Rift DK2 Optical tracking systems Wearable haptic devices (Moneybox Game and Labyrinth Game) |
The Moneybox Game focuses on grasp and reaching tasks with pronation/supination of the hand. The player is asked to grasp a golden coin and to insert it in a floating piggy bank. In the Labyrinth Game, a sliding token has to be driven through a maze by dragging it with the fingertip |
All the subjects completed the rehabilitation session, including both the gaming scenarios, without interrupting the treatment due to fatigue or other reasons. Together with positive comments reported after the rehabilitation session, results are encouraging for application of the method in a prolonged rehabilitation treatment |
| Keller and Van Hedel45 | Cerebral palsy (motor learning) | Adaptable exoskeleton Position sensors (Armeo Spring) |
Moorhuhn (Crazy Chicken) is an exergame with the goal of hunting birds of various sizes (and thereby various points). It requires the player to move and position the arm and hand quickly and accurately in the virtual environment and timely grasp the joystick to shoot at a chicken | The results showed the successful acquisition, transfer, and retention of upper extremity skills. The motor learning occurred when children trained their more affected arm with weight support in a playful, virtual environment |
| Keller et al46 | Cerebral palsy, stroke, and traumatic brain injury (arm rehabilitation) | Arm robot (ChARMin robot) |
The ChARMin platform is characterized by a hardware that is safe and highly adjustable and a patient-cooperative controller that supports arm movements in game-like scenarios (Tornalino, Airplane, Diver, Whack-a-Mole, and Spaceship Game) with an integrated audiovisual interface | These preliminary tests suggest that the ChARMin setup can be used as an advanced exercise tool for arm neurorehabilitation that optimally challenges children and adolescents with severely to moderately affected arm motor functions |
| Shokur et al47 | Spinal cord injury (lower limb somatosensory feedback) | Tactile shirt HMD Oculus Rift (—) |
Missing haptic sensation from the lower limbs was replaced by rich tactile stimulation on the skin of SCI patients’ forearms. This feedback was integrated with an immersive VR environment where a 3D human avatar was simulated. The 3D human avatar projected in the HMD could stand and walk and as it performed these movements, tactile feedback, reproducing the touch of the avatar feet on the ground, was delivered on the skin of the patients’ forearm through the employment of a haptic display (eg, the tactile shirt: see Integration of the virtual body avatars with the tactile shirt) | The addition of tactile feedback to neuroprosthetic devices is essential to restore a full lower limb perceptual experience in spinal cord injury patients, and will ultimately lead to a higher rate of prosthetic acceptance/use and a better level of motor proficiency. Interestingly, patients were never instructed on what the tactile feedback displayed or represented. As totally naïve subjects, they acquired vivid tactile/proprioceptive sensations after exposure to 1 minute of synchronous visuo-tactile stimulation (patients observed the 3D human avatar walking and received the tactile stimulation on their forearm). This suggests that such tactile feedback became intuitive to the subjects rather quickly. As such, we propose that our haptic display paradigm was capable of inducing patients to experience a proprioceptive illusion that allowed them to deduce the position of the virtual avatar legs relying solely on the tactile feedback |
| Dimbwadyo-Terrer et al48 | Spinal cord injury Motion capture systems to train activities of daily living |
CyberTouch™ CyberGlove (—) |
The virtual scene consists of 1 room, 2 shelves and a trench. The user is able to see her or his virtual hand in the scene, as well as virtual objects. A set of virtual geometric elements was created and can be randomly presented in different parts of the upper shelving for each trial | The first findings showed the possibility to conduct a training based on functional reaching movements in a virtual environment in people with spinal cord injury using a data glove and to obtain objective data through 2 functional parameters |
| Kim et al49 | Parkinson disease (neurorehabilitation) | HMD Oculus Rift DK2 (—) |
The virtual environment consisted of a cityscape with buildings, animated avatars, and an 800-m straight sidewalk. The avatars were added to provide a dynamic element to the virtual environment, and they were the only animated features of the environment. Movements through the environment were constrained to the forward direction, but participants were able to freely look around the scene while walking. The environment did not include any turns, doorways, or crossing of thresholds. The velocity of the simulation was synchronized to the speed of the treadmill, and the orientation of the participants’ viewpoint was synchronized with head orientation using an inertial measurement unit embedded in the HMD | Older adults and individuals with PD were able to successfully use immersive VR during walking without adverse effects. This provides systematic evidence supporting the safety of immersive VR for gait training in these populations |
| (Rohani and Puthusserypady50 | Attention deficit hyperactivity disorder (attention) | Microsoft Kinect (—) |
The classroom includes 6 pupil desks each having 2 seats, projection screen, posters, a soccer ball, several hula hoops, a wall clock, book shelves, and a first aid kit. Two windows in the left side of the room are facing out onto a road. The ceiling of the classroom contains a fan, projector, and 6 fluorescent lights. Also is seen a female teacher, her desk, as well as a computer on the desk, and a blackboard behind her | This work has successfully demonstrated a nonintrusive, low-cost, and portable system targeting attention in a motivating and engaging environment. The authors found the low-cost system to be good enough in practice, as the major limitation of BCI feedback system were related to the reliability and minimization of false classifications by their P300 speller, which they solved by a better and faster machine learning classifier based on support vector machines (SVM) |
| Pedroli et al51 | Dyslexia (reading abilities) | Microsoft Kinect Audio system (—) |
The tasks took place in the same Virtual Classroom, where patients were sitting at a desk and looking at the blackboard. All the visual stimuli were shown on the blackboard and the tasks were explained by a voice. All the instructions were presented before the tasks and repeated until the child understood. To respond to a target, the children had to raise 1 extended arm laterally and stop when the hand reached shoulder height | The results do not demonstrate an immediate effect on reading performance, suggesting that a more prolonged protocol may be a future direction, the presence of a significant decrease in the time of reading low frequency longwords supports the possible validity of the proposed approach. The protocol is innovative because it uses VR to improve attentional skills in children with dyslexia. This technology is able to involve children in nonconventional tasks and allow them to work in a virtual environment similar to the real one |
| Peruzzi et al52 | Multiple sclerosis (dual-task walking) | HMD Emagin, Z800 LCD screen Two magneto-inertial measurement units (—) |
Participants walked on the treadmill while watching a VR environment representing a tree-lined trail. Subjects were required to pass obstacles (puddles and logs) appearing on the trail. The specific simulation was chosen to address specific gait problems, common in multiple sclerosis (ie, decreased foot clearance, obstacle avoidance, and problems with planning). Successful and unsuccessful passes, as determined by the inertial measurements, were rendered to the subject during the trial with visual and auditory feedbacks. A cognitive concurrent task was added by asking subject to memorize the route to follow, which was shown to them prior to the trial. Several dynamic distractors were also added to the virtual environment to challenge subject’s attention | VR-based treadmill training program is feasible and safe for multiple sclerosis subjects with moderate disabilities and may positively affect gait under complex conditions, such as dual tasking and obstacle negotiation |
| Gagnon et al53 | Autosomal-recessive spastic ataxia of Charlevoix-Saguenay (measures of upper limb coordination) | Haptic device equipped with a custom-made handle instrumented with 3 force sensors (Virtual Peg Insertion Test—VPIT) |
VR environment displaying a pegboard tasks. Pegs can be grasped in the virtual environment by precisely aligning a cursor representing the position of the handle of the haptic device with 1 of the 9 pegs (distal coordination) and grasping the handle over a force threshold of 2 N (prehension strength) | The results demonstrate the potential to evaluate upper limb impairment, in particular impaired coordination, and monitor its progression over time |
| Grewe et al54 | Focal epilepsy (cognitive neurorehabilitation) | 360° VR apparatus, OctaVis Throttle joystick LCD touchscreens (—) |
Virtual medium-sized supermarket, which had a structure comparable with that of a real supermarket | A novel 360° VR environment demands real-world–like visual-spatial and motor actions and thus allows for the training of the respective cognitive abilities |
Abbreviations: BCI, Brain Computer Interface, EEG, electroencephalography, PD, Parkinson disease; VR, virtual reality.