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Abstract

Although the dominant frequency at 3 cpm of electrogastrography (EGG) is reported to shift to a higher frequency during motion sickness (MS), it is unclear whether the normal slow wave (NSW) disappears or not. The authors investigated changes in NSW using vector analysis of EGG. Fourteen subjects were exposed to a Coriolis stimulation to evoke MS. EGG was recorded from two sets of bipolar leads, placed perpendicular to each other representing x and y axes. Trajectories for each frequency were drawn on the x-y plane. The amplitude and phase difference at NSW were compared before, during, and after the stimulus for each subject. In those with a change in phase difference, changes in NSW and tachygastria were negatively correlated (P = -0.048), whereas in those without a change, they were not correlated. This indicated two different kinds of tachygastria due to MS: tachygastria with and without a change in NSW.

Electrogastrography in Autonomous Vehicles—An Objective Method for Assessment of Motion Sickness in Simulated Driving Environments

“…Since disturbances were expected in both ranges [31,32], statistical significance was unlikely to appear. Considering the most often shift to tachygastric range, slight increase of DF was expected as Tokumaru et al suggested [50]. In line with the expectations, the DF increased during AV simulation with p = 0.073.…”

“…The phenomenon of DF not in normal range is called gastric dysrhythmia. It is expected for the DF of slow wave and its power to increase (shift to tachygastric range) while experiencing sickness [28,31,49,50].…”

“…While researching EGG in motion sickness, Cheung and Vaitkus reported that inherent inter-subject variability makes it difficult to consider EGG a reliable indicator of MS [31]. After a few years, Tokumaru et al reported two different kinds of tachygastria due to MS-one with and one without a change in normal slow waves [50]. Himi et al measured nausea with EGG on people, watching an irregularly oscillating video, and discussed the role of autonomic nervous system in nausea [52].…”

Lessons Learned: Gastric Motility Assessment During Driving Simulation

“…This phenomenon is also called gastric dysrhythmia [17]. The same results were obtained during the assessment of nausea as a result of motion and simulator sickness [14,15,16,18,19,20]. To the best of our knowledge, all published EGG studies for SS assessment were performed under static conditions (in the absence of movement artifacts).…”

“…sinusoidal signal with a frequency ranging from 2 cpm (cycles-per-minute) to 4 cpm in healthy subjects-normogastric range [12,13]. In previous studies [14,15,16], a shift in the frequency of slow-wave activity from normogastric range was reported in healthy subjects as a consequence of nausea occurrence. This phenomenon is also called gastric dysrhythmia [17].…”