Cybersickness Symptom Profiles in Long-Duration Immersive AR (1090-003580) (Award Winning Abstract)
Start time: Tuesday, January 19, 2021, 1:00 PM End time: Tuesday, January 19, 2021, 2:00 PM Session Type: Research Abstracts (Completed Studies)
Cybersickness resulting from use of virtual reality (VR) devices has been studied for decades. Using the Simulator Sickness Questionnaire (SSQ),(2) the typical VR symptom profile has been well-characterized; typically greater disorientation (D), then nausea (N), and little oculomotor disturbances (O), a D>N>O profile(1,3,5). However, the same cannot be said for augmented reality (AR) systems. Many assume that since AR is not fully immersive with intense visual-vestibular mismatches, its capacity for causing adverse physiological symptoms is reduced. If AR technology does indeed impose substantial maladaptations, this could present safety risks post exposure. It is thus critical to assess the physiological impact of AR exposure and its implications on military medical simulation safety and efficacy. It is hypothesized that AR systems will lead to a symptom profile of O>D>N, with low levels of nausea allowing for longer exposure duration but with the potential for prolonged aftereffects.
A total of 48 participants (mean age=25.45 [SD=7.36] 19 females and 29 males) participated in the study. The experiment was a mixed design, with 2 (display types) × 2 (exposure protocol) between factors and a 5 (post exposure measurement time) within factor. The display types were HoloLens (n=24) and Magic Leap (n=24). The exposure protocols were either three (3) 40-min sessions or six (6) 20-min sessions, both with 30-min breaks between sessions. The post exposure measurement times were 0, 15, 30, 45, and 60 min post exposure, with the SSQ being measured at each time. Military medical focused content was developed using Unity game engine. Four 20-min AR scenarios were developed, two focused on treating a massive hemorrhage and the others focused on treating respiration failure due to tension pneumothorax.
Previous VR research has shown that medium to high intensity SSQ scores (the 50th or higher percentile, with a Total SSQ score of 20 or higher) suggest significant cybersickness is being experienced.(4) Total SSQ scores for the Magic Leap did not exceed 20 for any of the post exposure measurement time periods. In comparison, total SSQ scores remained approximately 20 for each of the post exposure periods for the HoloLens. Preliminary analyses using nonparametric Friedman Test showed that there was a significant difference in Total SSQ score compared to baseline only for the HoloLens in the 3-40min protocol X2r(5) = 38.99, p = .001. As expected, both AR HWDs followed an O>D>N SSQ symptom profile. A one-way ANOVA, F(1,100) = 3.90, p = .05 showed that the HoloLens Oculomotor SSQ scores were significantly higher than those for the Magic Leap, suggesting higher levels of eyestrain, headaches, visual fatigue, and blurred vision are associated with the HoloLens.
Immersive AR medical training solutions hold promise to accelerate training expertise given the capability to present battlefield conditions in a more realistic, embodied, and contextualized manner. Understanding the potential for cybersickness and associated symptom profiles can assist in the design of optimal AR training protocols. This study confirmed an O>D>N SSQ symptom profile for both AR display types. In the HoloLens, high levels of oculomotor symptoms were sustained 60 min post exposure for 40 min exposure durations. Thus, this preliminary research suggests that time within AR training systems may best be kept to 20-30 min, with breaks of at least 30 min between sessions to minimize prolonged adverse visual aftereffects. It seems that even though the symptom profile for AR is loaded on oculomotor symptoms, which are less incapacitating than the nausea symptoms associated with VR systems, the adverse symptoms can linger for long periods of time post AR exposure, just as in VR.