Available at: https://digitalcommons.calpoly.edu/theses/228
Date of Award
MS in Electrical Engineering
Between 1994 and 2003 spatial disorientation resulted in at least 202 aircraft
accidents, 184 of them resulting in fatalities. Galvanic Vestibular Stimulation (GVS)
provides a cost effective and safe way to simulate spatial disorientation and
potentially test pilot’s vestibular system prior to aircraft operation. This experiment
investigates the use of GVS as an indicator of motion sensitivity and explores the
effects of GVS on flight simulation performance. Bilateral bipolar rectangular pulse
electrical stimulations were given to subjects via skin-mounted electrodes placed over
each mastoid process to stimulate the vestibular system with roll and yaw sensations.
Two studies were conducted in this work: one on motion sensitivity and one to
examine the effects of GVS during flight simulator use.
The motion sensitivity test consisted of an alternating GVS sequence to simulate
rolling back and forth. The sequence did generate motion sickness in two out of 12
subjects. Results show no correlation to motion history scores calculated from
Kennedy’s Motion Sickness Questionnaire (MSQ).
The flight simulator test coupled automatically generated congruent, conflicting,
and sham orientation sensations to the roll angles of the aircraft. The stimulations
used in this test did not indicate any effect on the simulator flight performance of the
subjects. Feedback from subjects during this test raised concern over the delay
between left- and right-side stimuli. Further testing to reduce the surface skin
sensation showed that a ramp or increasing exponential waveform not only reduced
the sensation of current entering the body but significantly increased the orientation
sensations resulting from the stimulation. Increasing the orientation response and
decreasing the sensation of current breaking the surface of the skin provides a much
more desired stimulation for each of the tests in this experiment and any other future
tests related to GVS.