Date of Award

12-2009

Degree Name

MS in Electrical Engineering

Department

Electrical Engineering

Advisor

Lynne Slivovsky

Abstract

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.

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