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

Over the past decade, Serious Games (SG) and Immersive Virtual Reality (IVR) have gained increasing interest in rehabilitation. However, in IVR the Head-Mounted Displays (HMDs) introduce limitations such as nausea, eye fatigue, and accessibility constraints. As an alternative, low-immersion games using standard monitors can be employed, though they sacrifice spatial correspondence during user interaction with virtual objects. To address it, this paper presents the development of a SG for upper limb (UL) rehabilitation, incorporating a custom wireless wearable device with vibrotactile haptic feedback to restore spatial correspondence. By combining Leap Motion controller (LMC) based on hand tracking, the system enables natural movement interaction in a closed kinematic chain, offering a viable compromise between immersion and usability. Additionally, three virtual scenarios were developed to train pronation/supination, pinch grip, ulnar/radial deviation, as well as wrist, elbow and phalange flexion/extension. User experience (short AttrakDiff), workload (NASA-RTLX), usability (SUS scale), and functionality were evaluated in healthy participants divided into two groups. Group 1 (n=13) used only LMC, while Group 2 (n=9) used LMC and the wearable device. The results shown that the system was perceived as more functional in Group 2, in addition, an increase in usability (from 74.71 to 80.83) and improvements in feedback, movement precision and quick response were observed in this group. These findings indicate that the wearable device signicantly improves spatial correspondence during interaction, making the system a promising option for motor rehabilitation in desktop VR enviroments.