Mixed-reality assistive robotic power chair simulator for Parkinson's tremor testing.

This note describes the development of a mixed-reality assistive robotic wheel chair simulator for testing of Parkinson's tremor mitigation and operator assistance. It consists of a power chair (PCh), roller dynamometer, head mounted virtual reality (VR) display, computer with VR game engine, and microcontroller to interface the PCh and computer. Unlike past VR PCh simulators, both a tremor notch filter and basic collision avoidance is implemented. Further, the simulator identifies the Parkinson's tremor frequency. Operator performance is assessed using deviations from a given route and velocity profile. To demonstrate the simulator's operation, an operator with Parkinson's tremor drove the PCh down two 20 m long hallways connected by a 90∘ turn while operating data was collected. Results show less variation in velocity tracking with use of the notch filter than without it; route tracking was nearly the same. Advantages of the simulator compared to a wholly physical approach are low cost, improved safety, portability, small footprint, and environments and robotic features are virtual.