Investigating vestibular evoked potentials as feedback signal in a vestibular neuroprosthesis. Relation to eye movement velocity

Patients suffering from bilateral vestibulopathy experience a decrease of physical and social functioning that cannot be compensated for by rehabilitation exercises. A vestibular neuroprosthesis could potentially improve the quality of life of those patients significantly. With current prostheses, reflexive eye movement (VOR) is recorded to evaluate stimulation efficacy. However, this measurement is not fed back to the device to monitor and adapt stimulation. We believe that a closed-loop vestibular neuroprosthesis could increase performance and are investigating vestibular evoked potentials (VEP) as a complementary feedback signal. We recorded VEP through the masker-probe method in one guinea pig; the VOR signal was filtered and differentiated to retrieve the eye velocity signal. Here, we report a piecewise linear relationship between peak eye velocity and current amplitude as well as the positive wave of VEP.