Galvanic Vestibular Stimulation Applied to Flight Training

• Main Author: Hanson, Joel D
• Format: Others
• Published: DigitalCommons@CalPoly 2009
• Subjects: Galvanic; vestibular; stimulation; GVS; flight training; Biomedical; Other Electrical and Computer Engineering
• Online Access: https://digitalcommons.calpoly.edu/theses/228; https://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1239&context=theses

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.