An Immersive Virtual Environment for Visuo-Vestibular Therapy

The sense of equilibrium aggregates several interacting cues. On patients with vestibular loss, vision plays a major role. In this study, the goal is to propose a new immersive therapy based on 3D optokinetic stimulation. We propose to demonstrate that 3D monoscopic optical flows is an efficient tool to stimulate adaptive postural adjustment. We developed an immersive therapeutic platform that enables to tune the difficulty of the balance task by managing optic flow speed and gaze anchoring. METHODOLOGY: the immersive sessions proposed to vestibular areflexic patients are composed of a repetition of dynamic optic flows, with varying speed and presence or not of a gaze anchor. The balance adjustments are recorded by a force plate, and quantified by the length of the center of pressure trajectory. RESULTS: Preliminary analysis shows that (i) Patients report a strong immersion felling in the motion flow, triggering more intense motor response to fight against fall than in standard opto-kinetic protocols. (ii) An ANOVA factorial design shows a significant effect of flow speed, session number and gaze anchor impact. CONCLUSION: This study shows that 3D immersive stimulation removes essential limits of traditional opto-kinetic stimulators (limited 2D motions and remaining fixed background cues). Moreover, the immersive optic flow stimulation is an efficient tool to induce balance adaptive reactions in vestibular patients. Hence, such a platform appears to be a powerful therapeutic tool for training and relearning of balance control processes.