Fig. 2.

Patient #4 with normal VOR gains. The left panels show the eye and head velocity during head impulses to the left (top) and right (bottom) recorded with ICS Impulse goggles. The right panels show the equivalent data recorded with the new, custom iPhone application. During the HIT, the eyes and the head move by an equal amount (VOR gain ∼1.0), so green traces (reflecting eye movements) are superimposed on head movements (orange and blue). Note that the testing is performed sequentially, so some differences may be real; others, however, may be artifactual (e.g., iPhone “wiggly” eye traces from 100–200 ms, likely from noisy measurement). HIT, head impulse test; VOR, vestibulo-ocular reflex.