Augmenting Virtual Reality Terrain Display with Smart Shoe Physical Rendering: A Pilot Study.

Haptic terrain rendering is limited in existing Virtual Reality (VR) systems. This article describes integration of the Smart Shoe (SS) for physical terrain display with the TreadPort VR system. The SS renders both gross sloped terrain and subtle sensations of stepping on small objects or uneven surfaces. The TreadPort projects terrain on the floor and the SS renders terrain that the user steps upon via motion tracking. The research is motivated towards eventually providing gait training for people with Parkinson's Disease (PD), hence this work presents a pilot study evaluating haptic terrain rendering with healthy elderly and PD participants wearing the SS within the TreadPort. Uneven cobblestone surfaces are rendered by the SS as the participant steps on their graphical representation in VR. While posthoc analysis shows the study is underpowered, kinematic and spatiotemporal results derived from motion capture data demonstrates kinesthetic response (e.g., increased maximum ankle angle and minimum toe clearance, reduced minimum ankle angle and knee angle) provided by the SS. Questionnaire data shows increased VR realism and difficulty walking on cobbled terrain using SS rendering. Thus, results indicate that the integrated haptic system demonstrates promise in potential gait training for PD in future work.