Virtual Reality and Assistive Technologies: A Survey <s> VII. DISCUSSIONS ON VR-BASED REHABILITATION <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> VII. DISCUSSIONS ON VR-BASED REHABILITATION <s> The objective of this study was to provide experimental data to support a proposed model of VRbased intervention. More specifically our goal was to examine the relationships between cognitive and motor ability and performance within virtual environments. Thirteen participants who have had a stroke participated in the study. They each experienced three virtual environments (Birds & Balls, Soccer and Snowboard) delivered by the GX- video capture system. After each environment they complete a scenario specific questionnaire and Borg’s scale for perceived exertion. Their cognitive, motor and sensory abilities were measured as well. The participants’ responses to the VR environments showed that they enjoyed the experience and felt high levels of presence. The results also revealed some moderate relationships between several cognitive abilities and VR performance. In contrast, the motor abilities and VR performance were inversely correlated. In addition, there was a relationship between presence and performance within the Soccer environment. Although these results support some components of the proposed model it appears that the dynamic nature of the virtual experiences would be more suited to comparisons with different measures of motor ability than those used in the current study. <s> BIB002 </s> Virtual Reality and Assistive Technologies: A Survey <s> VII. DISCUSSIONS ON VR-BASED REHABILITATION <s> In recent years, clinical studies have begun to demonstrate the effectiveness of VR as an intervention tool for a variety of neurological conditions. There remain, however, a number of important issues that must be addressed in order to determine how widely VR-based intervention should be applied, and the user and platform characteristics that may be important when using VR in clinical settings. One of the unresolved issues that must be addressed is the suitability of particular VR platforms in relation to the therapeutic goals one wishes to achieve. Studying and identifying the characteristics of each platform may assist the therapist in choosing a suitable VR platform for the patient's needs. The purpose of this paper is to describe the results of a study of healthy participants (N -- 89) using 2 different VR platforms in combination with 1 of the 2 virtual environments that was designed to compare the sense of presence, incidence of side effects, perceived exertion, and performance. The data demonstrate significant differences in some of the key characteristics of both VR platforms and environments as they affect participants' sense of presence, performance, side effects, and exertion. We conclude that when seeking a suitable VR therapeutic application, the user's characteristics together with attributes of the VR platform must be taken into consideration since both appear to have an impact on key outcome measures. <s> BIB003 </s> Virtual Reality and Assistive Technologies: A Survey <s> VII. DISCUSSIONS ON VR-BASED REHABILITATION <s> Stroke is the leading cause of long term disability among adults in industrialized nations. The partial paralysis that stroke patients often experience can make independent living difficult or impossible. Research suggests that many of these patients could recover by performing hundreds of daily repetitions of motions with their affected limbs. Yet, only 31% of patients perform the exercises recommended by their therapists. Home-based stroke rehabilitation games may help motivate stroke patients to perform the necessary exercises to recover. In this paper, we describe a formative study in which we designed and user tested stroke rehabilitation games with both stroke patients and therapists. We describe the lessons we learned about what makes games useful from a therapeutic point of view. <s> BIB004 </s> Virtual Reality and Assistive Technologies: A Survey <s> VII. DISCUSSIONS ON VR-BASED REHABILITATION <s> To people who are visually impaired, sensory substitution requires conversion from distal visual data to proximal haptic cue. The challenge is to identify the optimum haptic cues that will make a common haptic "language", which can eventually be used to convey information about facial expressions to the individuals who are blind. Once this language has been developed, the next challenge is learning and training. We propose a dynamic haptic tool for simultaneous learning and interaction with a proposed haptic language. We call this application "Haptic mirror", an interactive haptic-based reflection of one's self which can be comparable to a visual mirror. Once the user has acquired this language, it can be used to convey the facial expressions of social peers. <s> BIB005
In a VR-based rehabilitation, a target-oriented training along with a suitable VR platform is essential for faster recovery. For example, with HMD, certain participants reported to experience dizziness or nausea when exposed to a VE for a long period of time BIB002 . Though HMD provides better immersion, these participants should avoid using HMD or options can be provided for switching between monitor and HMD. Though latency is an issue with VR, all VR-based applications do not suffer from it; choosing a suitable VR platform along with a suitable virtual task can minimize this problem. Most often motor recovery is associated with intensive therapy that requires the user to perform hundreds of daily repetitions of motions of the paretic limb. But only one third of post-stroke patients were reported to perform exercises as recommended by their therapists BIB004 ). Traditional one-on-one therapy is labor-intensive and expensive. As discussed above, a VE provides continuous and gradual adaptation of the exercise parameters to the users performance and ability under a variety of simulated circumstances. Wii-motes or other visual feedback-based assistive technologies are portable, affordable, flexible, and good for practice at home for necessary motor recovery. These assistive technologies are simple, yet powerful in rehabilitation. Integarting popular exercises like crouching or halfcrouching along with progress in a game makes the overall environment less monotonous. A VE enhanced with exercise equipment works as a better practice ground than non-VR systems for continual development of kinesthetic memory via intensive training of the paretic limb. In motor-rehabilitation training, force feedback haptic devices not only address patients kinematics but also focus on the kinetics of the hand and wrist by assisting patients grasp of virtual objects with their deficient arm. Thus force feedback-based VR therapy was found to be more effective and produced faster results in comparison with visual feedback-only VR systems BIB001 ). This haptic feedback can be adapted to specific tasks to be fully exploitable  . The device handle can be replaced to incorporate different removable grips, i.e., thumbpad, thimble, or hand glove to facilitate interaction with the VE. A force feedback-based dynamic VE could prove to be more flexible and scalable, giving eventually access to unlimited sets of educational cases to the blind in comparison with conventional method of teaching. Though in our discussion, it has not been explicitly mentioned about the empowerment of the deaf, all VR-based rehabilitation systems can be deployed for the cognitive empowerment of the deaf individuals and be quite helpful for better integration of such population into the mainstream of society As shown in Figure 17a , using a conventional Tadoma technique, a deafblind individual physically accesses others mouth to receive a message. People who are both deaf and blind find difficulty while communicating among themselves especially when communication involves more than two people. Applications such as a haptic mirror may facilitate communication among deafblind individuals as well; while one person wants to communicate, others will be able to examine his haptic facial features, and understand what message he wants to convey BIB005 . In order to facilitate better interaction, dynamic tactile pin arrays may be used so that the blind can feel the VE with their own hands. This scenario is demonstrated in Figure 17b . As discussed in the previous section, question arises whether putting on an extraneous outfit like HMD or interacting via haptic devices can persistently affect patients performance and rehabilitation. Again, choosing a suitable VR application can be a solution. As the philosopher Polyani observed that prior to full achievement of a skill (e.g., learning and interacting with a new interface), the users awareness focuses on the components of the skill. As skill develops, the user eventually becomes more focused on the contents of the VE, and less aware of the interface used in it  . After becoming accustomed to the VE, users eventually experience more natural interaction. Apart from that, performance during practicing may differ not only between the VR platforms but can also be influenced by the gender or age of the participants and the virtual task to be performed BIB003 ). Male participants may perform better during virtual soccer games while their female counterparts may be more motivated to a virtual fashion show. Thus if negative findings with respect to a VE can be carefully considered, side effects can be substantially reduced.