[Original survey and analysis method of the vestibulo-ocular transfer using the microcomputer. Contribution to the...

This report presents a new and well-tolerated technique that quickly tests the labyrinthic system by moving the head, via a helmet mounted on a servo controlled torque motor, with a sinusoidal stimulus small enough (10 to 15 degrees of amplitude) to avoid the triggering of quick phases. A personal PC (Olivetti M24) digitizes the amplified and filtered eye and head movement data for storage and analysis. Compared to the low frequency patterns of stimulation by the sinusoidal acceleration test (SHA), our procedure, because of the reduced mass of inertia, investigates the bandwidth of frequencies corresponding to those normally incurred during natural movements. For each of 14 normal persons, 1 patient with Ménière's disease and 2 with a history of labyrinthic trauma, the phase difference of the eye position relative to the head and the gain are computed. The mean phase lag of 180 degrees, from 0.1 Hz to 2.5 Hz, in the normal group maintains steady gaze during head rotation in significant opposition to the phase lag, varying at 1 Hz from 264 to 354 degrees, of the patients with vestibular disorders. The phase lag is the most reliable parameter in detecting vestibular dysfunction and its correct determination can be made in a few minutes, at physiological frequencies, by our low-cost simplified method.