Evaluating Balance Recovery Techniques for Users Wearing Head-Mounted Display in VR

Area of Science:

• Human-Computer Interaction
• Virtual Reality Safety
• Balance and Gait Analysis

Background:

• Room-scale 3D tracking in virtual reality (VR) enhances immersion but poses risks of falls due to obstructed vision.
• Falls can occur from unexpected obstacles or shifts in the center of mass outside the margin of stability.
• Assessing balance recovery methods is crucial for safe VR navigation.

Purpose of the Study:

• To evaluate the effectiveness of different balance recovery interventions and their timing during VR-induced falls.
• To compare video-see-through and auditory warnings as assistive techniques.
• To determine optimal intervention timing for fall prevention and recovery in VR.

Main Methods:

• A controlled experiment using a tether-release protocol to induce falls in 17 subjects during a VR task.
• A two-by-two factorial design evaluating video-see-through and auditory warnings at two timings: fall onset and 500ms prior.
• Measurement of balance recovery success under different intervention conditions.

Main Results:

• Video-see-through assistance provided 500ms before fall onset significantly improved users' ability to recover balance.
• Intervention at fall onset showed no significant benefit, performing similarly to the no-intervention baseline.
• Auditory warnings were not explicitly detailed in their effectiveness compared to video-see-through, but the timing of video-see-through was the critical factor.

Conclusions:

• Early visual intervention (500ms prior to fall onset) is effective for balance recovery in VR.
• Late visual intervention (at fall onset) can be detrimental or ineffective, highlighting the importance of timing.
• Future research should explore other sensory feedback mechanisms and refine intervention timing for enhanced VR safety.