Postural Stability of People With Balance Impairments in Virtual and Augmented Reality
The objective of this research is to improve the balance in Virtual and Augmented Reality systems for users with balance impairments. Previous research has shown that most users experience some imbalance in a fully immersive Virtual Environment (VE) (i.e., wearing a Head-Mounted Display (HMD) that blocks the user's view of the real world). However, this imbalance is significantly worse for users with balance deficits. Persons with balance impairments often depend more on visual feedback than persons without impairment to maintain their balance. Thus, this research aims to determine an effective visual feedback technique to improve the balance of persons while using VEs to improve the accessibility of HMDs. I investigated how a static rest frame (SRF) (e.g., a cross-hair always rendered in the same position on the user's display screen) impacts the participants' balances in Virtual Reality (VR) and Augmented Reality (AR). Results indicate that an SRF significantly improves balance in VR and AR for users with MS. While SRF was proved to be a successful method to improve the balance in VR and AR, I also discovered that lower frame rate and lower field of view, not display resolution is responsible for postural instability in VR. I also successfully used scaling of participants movement to improve their reach in virtual reality. Based on these results, I propose guidelines for designing more accessible VEs for persons with balance impairments.