A Serious Game for Upper Limb Rehabilitation Implementing a Custom Vibrotactile Wireless Wearable Device and Leap Motion

Over the past decade, serious games and virtual reality have gained increasing relevance in upper-limb rehabilitation, yet desktop virtual reality solutions often suffer from reduced spatial correspondence and limited sensory feedback. This work presents the design and preliminary evaluation of a desktop virtual reality-based serious game that combines Leap Motion Controller hand tracking with a custom wireless vibrotactile wearable device to support upper-limb rehabilitation training. Three training scenarios were implemented to target pronation/supination, pinch grip, ulnar/radial deviation, and wrist, elbow, and finger flexion/extension. Usability (System Usability Scale, SUS), user experience (short AttrakDiff), and perceived workload (Raw NASA-TLX), together with functionality and perception questionnaires, were collected from healthy participants randomly assigned to two groups (Group 1: $n=13$, LMC only; Group 2: $n=9$, LMC plus wearable). Across all instruments, the configuration including the wearable device tended to obtain higher usability ratings, more desirable pragmatic and hedonic quality scores, and lower overall workload means than the LMC-only configuration, with moderate effect sizes but limited statistical power due to the small samples. Participants in the wearable condition also reported clearer feedback, a perceived improvement in movement precision, and a stronger perceived alignment between real and virtual actions. These findings suggest that the proposed system may serve as a promising user-centered prototype for desktop VR-based upper-limb rehabilitation and provide preliminary design evidence to support future clinical and kinematic validation studies with larger cohorts.