## 3 Practical Applications of VR in CR
### Individual Non-immersive Systems  
Individual non-immersive rehabilitation typically refers to a cognitive rehabilitation training system that utilizes virtual reality technology but does not provide an immersive experience. Instead, it uses other media or tools to provide cognitive rehabilitation training for a single patient. A significant advantage of an individual non-immersive virtual reality rehabilitation therapy system lies in its intuitive user interface and simple setup process [35; 36; 37], which greatly reduces the risk of user disorientation. Moreover, its ease of use and maintenance makes it an affordable option, thus making it more suitable for large-scale promotion and popularization. This system is primarily applicable to patients with traumatic brain injury, stroke, and Alzheimer's disease.  
[PERSON] et al. (2014) [38] proposed a real-time 3D computer vision-assisted system for monitoring psychomotor exercises in 2014. The system is designed to assess and evaluate body structure dysfunction and left-right confusion. It achieves monitoring through the tracking of human head and hand joints and the detection of facial feature-susing depth information provided by the Kinect device. The system overcomes the limitations of 2D computer vision methods and is robust to significant changes in the working environment and lighting. The Kinect device has been proven to be an affordable off-the-shelf product that is useful for the development of applications in many fields, including rehabilitation, due to its ease of use and good performance. To address the issue of monotony in traditional rehabilitation therapy, [PERSON] et al. (2015) [39] proposed a conceptual framework for designing a game-based cognitive rehabilitation system in 2015 and developed a rehabilitation game system (RGS) for cognitive rehabilitation. Patient assessments can \"tailor\" training for specific cognitive functions. Therapists create this game-based training based on the patient's abilities, limitations, and preferences. To investigate the effect of a wearable multi-inertial sensor virtual reality rehabilitation system on improving upper limb function in children with brain injury, [PERSON] et al. (2021) [40] conducted a randomized controlled trial study on 80 patients with brain injury in 2021. The virtual reality rehabilitation system includes games that promote wrist and forearm joint movements using wearable inertial sensors. This is a non-immersive virtual reality system where sensors upload user information to a computer, and the computer screen moves in sync with the user's active movements. The virtual reality rehabilitation program consists of multiple games and modules, including daily living activities and movement performance promotion. At the beginning of the training, upper limb ability is assessed using virtual reality equipment to determine the initial difficulty level. Then, the difficulty level of the training scenario is adjusted based on each individual's performance parameters during each training session. During and after the practice, both auditory and visual feedback are provided on the computer screen. The experimental results indicate that the upper limb rehabilitation effect was better in the experimental group using the virtual reality method.  
By comparing the three individual modes of rehabilitation systems, it can be observed that the limited immersion of an individual non-immersive virtual reality rehabilitation therapy system may not provide as engaging or effective a cognitive rehabilitation experience as the more immersive types.