Haptic-Enhanced Mixed Reality for Upper Limb Rehabilitation in Parkinson's Disease.

We have developed a portable and programmable system, the Virtual Upper Arm Rehabilitation Simulation (VUARS), to address upper limb movement difficulties in Parkinson's Disease (PD). VUARS uses a mixed reality headset (Microsoft HoloLens 2) and a haptic stylus (Geomagic Touch), building on an existing tabletop system. It offers personalized features such as customizable button design, size, and arrangement. Additionally, it provides multimodal feedback capabilities, developed through a thorough calibration process, via synchronized mixed reality button graphics and haptic feedback rendering in the Unity 3D game engine. To evaluate the developed system, a user study was conducted with 22 healthy individuals and 9 PD individuals. The efficacy of the VUARS was validated through both collected quantitative and qualitative data, such as trial and total task completion time, hand motion tracking data, and NASA TLX data. The results indicated that haptic feedback and personalized features improved task completion times and user experience, with 67% of the target demographic (PD individuals) showing statistical differences. However, further research is needed before complete adoption of VUARS in clinical settings due to a lack of statistically significant differences between traditional and VUARS systems currently.