Virtual Reality and Assistive Technologies: A Survey <s> Haptic VEs for mobility and cognitive impairments <s> 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 patient's 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. <s> BIB001 </s> Virtual Reality and Assistive Technologies: A Survey <s> Haptic VEs for mobility and cognitive impairments <s> Carpal tunnel syndrome is caused by the compression of the median nerve as it transits the carpal tunnel, with an incidence of about 1% of the population. If surgery is needed, the treatment involves decompression of the median nerve followed sometimes by musculoskeletal outpatient rehabilitation. This paper presents a proof-of-concept pilot clinical trial in which the Rutgers Masters II haptic glove was tested on five subjects, who were two weeks post-hand surgery. Subjects trained for 13 sessions, 30 min per session, three sessions per week, and had no conventional outpatient therapy. Computerized measures of performance showed group effects in hand mechanical energy (1200% for the virtual ball squeezing and DigiKey exercises and 600% for the power putty exercise). Improvement in their hand function was also observed (a 38% reduction in virtual pegboard errors, and 70% fewer virtual hand ball errors). Clinical strength measures showed increases in grip (by up to 150%) and key pinch (up to 46%) strength in three of the subjects, while two subjects had decreased strength following the study. However, all five subjects improved in their tip pinch strength of their affected hand (between 20%-267%). When asked whether they would recommend the virtual reality exercises to others, four subjects very strongly agreed and one strongly agreed that they would. <s> BIB002 </s> Virtual Reality and Assistive Technologies: A Survey <s> Haptic VEs for mobility and cognitive impairments <s> Attention deficits are one of the most profound problems facing the traumatic brain injured individual. The Traumatic Brain Injury (TBI) inpatient population in the rehabilitation unit is difficult to study with new technology because it is often very difficult to render and evaluate such interventions in the short time span when a patient is still in the hospital, even though that is precisely the time when clinical attentional therapy is considered most critical. We developed and performed a preliminary test of a haptic/graphic paradigm for improving attention and concentration in early stages of recovery in the TBI inpatient population. Six TBI patients and three healthy controls were exposed to a minimal distraction/minimal interaction environment while reaching for a visual target. Our initial results showed (1) the subjects tolerated the experience, (2) the number of targets acquired in successive one-minute intervals indicated a sustained attention for the task, and (3) haptic interaction in such an environment was well tolerated, engaging, and enjoyable -- often considered a game. These findings have provided the foundation for a larger, intensive, protracted study with repeated treatment. <s> BIB003 </s> Virtual Reality and Assistive Technologies: A Survey <s> Haptic VEs for mobility and cognitive impairments <s> This paper presents the design and characteristics of a five-fingered haptic interface robot named HIRO III. The aim of the development of HIRO III is to provide a high-precision three-directional force at the five human fingertips. HIRO III consists of a 15-degrees-of-freedom (DOF) haptic hand, a 6-DOF interface arm, and a control system. The haptic interface, which consists of a robot arm and hand, can be used in a large workspace and can provide multipoint contact between the user and a virtual environment. However, the following problems peculiar to a multi-DOF robot have arisen: a large amount of friction, a backlash, and the presence of many wires for many motors and sensors. To solve these problems, a new mechanism and a wire-saving control system have been designed and developed. Furthermore, several experiments have been carried out to investigate the performance of HIRO III. These results show the high-precision force display and great potential of HIRO III. <s> BIB004 </s> Virtual Reality and Assistive Technologies: A Survey <s> Haptic VEs for mobility and cognitive impairments <s> In the past decade, several arm rehabilitation robots have been developed to assist neurological patients during therapy. Early devices were limited in their number of degrees of freedom and range of motion, whereas newer robots such as the ARMin robot can support the entire arm. Often, these devices are combined with virtual environments to integrate motivating game-like scenarios. Several studies have shown a positive effect of game-playing on therapy outcome by increasing motivation. In addition, we assume that practicing highly functional movements can further enhance therapy outcome by facilitating the transfer of motor abilities acquired in therapy to daily life. Therefore, we present a rehabilitation system that enables the training of activities of daily living (ADL) with the support of an assistive robot. Important ADL tasks have been identified and implemented in a virtual environment. A patient-cooperative control strategy with adaptable freedom in timing and space was developed to assist the patient during the task. The technical feasibility and usability of the system was evaluated with seven healthy subjects and three chronic stroke patients. <s> BIB005
A number of rehabilitation applications have been developed using haptic VEs. Broeren et al. used 3D Systems Touch X device for rehabilitation training of stroke patients with hemiparetic arms (Broeren, Rydmark, and Sunnerhagen 2004). The patient had to grasp the haptic device with their paretic hand to strike a ball to knock down bricks in the VE (Figure 10a ). Subjects received credit for knocking down bricks and collected negative points for missing the ball. The game was customized to operate in four different speeds. After playing the game for a period of four weeks in twelve 90-minute sessions, the subject reported that he was able to use his left arm in several Activities of Daily Life (ADL) that were previously impossible for him (e.g., buttoning his shirt, emptying the dishwasher with two hands). Phantom 1.0, a 3 DOF force feedback haptic device by 3D Systems had been used for VE-based motor rehabilitation training (Jarillo-Silva, Domnguez-Ramrez, and Parra-Vega 2010). Patients had to hold the handle of the device and move their hands along a predetermined trajectory to solve a maze. In active mode, patients guided themselves to follow up the trajectory whereas in passive mode, patients were guided by the device. Experimental results demonstrated that haptic guidance helped patients gradually recover their motor movements. Dvorkin et al. integrated haptics in VEs to improve attention and concentration in early stages of recovery of the traumatic brain injury (TBI) inpatient population BIB003 ). It was hypothesized that isolated training with a focused task would be best for restoring attention. Subjects had to interact with the VE by moving the handle of Phantom Premium 3.0 (6 DOF) to interact with a number of 3D spheres (Figure 10b) . A three-dimensional, largeworkspace haptics/ graphics system called the virtual reality and robotic optical operations machine (VROOM) was used. Integration of augmented reality into the system made the environment more immersive allowing the users to view virtual objects superimposed onto the real world. As the haptic cursor moved towards a sphere, sometimes attractive force was generated; sometimes a repulsive force pushed the hand away from the target sphere. Patients were found to be highly motivated throughout the experiment; the virtual interaction seemed to be well-tolerated, engaging, and enjoyable. Reiner et al. demonstrated that a visuo-haptic VE creates a better sense of presence among the subjects  ). In this VE, subjects used 3D Systems haptic devices to hit a wall with a number of cubes. While moving the cubes in a VE, some cubes felt heavier than others; some started rolling when touched. Subjects were reportedly found to be highly engaged in the VE. Ungrounded exoskeleton RMII as demonstrated in Figure 11 had been used for VR-based rehabilitation of stroke patients and orthopedic rehabilitation BIB001 ). Patients wearing RMII were asked to perform several virtual tasks to determine hand range of motion such as continuously wiping off a window to reveal a different intriguing landscape every time. Some activities required competition with a virtual opponent to measure the speed of movement as the user was asked to catch a virtual ball by closing the palm as fast as possible. In finger fractionation exercises, the movement of an active finger depressed the corresponding key of the virtual piano. RMII had also been used for finger strength exercises that required pressing the attached actuators to fill virtual pistons. Most of the patients showed remarkable improvement in daily functional activities. One post-stroke patient who could not button his shirt was able to do so after he had undergone the training. The same VR system had been used for the treatment of carpal tunnel syndrome that causes numbness and tingling of the thumb, index, middle, and ring fingers. Significant positive effects had been observed among the patients after a number of training sessions BIB002 ). The RMII had been used for orthopedic rehabilitation exercises in a VE that involve interactions with dynamic objects and physical modeling of elasticity and plasticity via grasping and squeezing activities while force feedback was felt by the patient (Popescu, Burdea, and Bouzit 1999). Here, instead of a single Haptic Interaction Point (HIP) at each fingertip, a simplified Haptic interaction Mesh (HIM) was considered around each fingertip and the intersection points between the virtual object and HIM were considered in elastic/ plastic deformation simulation. Grounded exoskeletons like HWARD had been used to practice grasping activities both in real and virtual environments  . With ARMin, users can practice Activities of Daily Life (ADL) in an enhanced VE with a higher sense of engagement (Nef, Mihelj, and Riener 2007; BIB005 ). MAHI Exo-II can be used in a virtual reality environment for post-stroke rehabilitation, or for individuals with spinal cord injuries or lacking strength in their arms or wrists (Gupta and OMalley 2007;  . HIRO III provides a high precision threedirectional force at the five human fingertips. Figure 12 demonstrates the interaction mechanism with HIRO III and the positions of the fingertips as shown with red dots while grasping, lifting, and moving a virtual object BIB004 ). Grounded exoskeletons are found to be highly effective in the rehabilitation of upper limb paralysis because they can be applied to multiple joints. This flexibility allows researchers to investigate rehabilitation of fine motor control and a larger range of motion (Wagner 2014).