# Motion Sickness in Mixed-Reality Situational Awareness System
## 7 Conclusions  
This research was aimed at improving the user experience of a mixed-reality situational awareness system. The results of this study can be applicable for VR applications that display a live pass through camera feed for the user, but, as this research was primarily conducted on a particular system, they cannot be generalized for general-purpose VR systems. Additionally, it should be noted that the simulation results were primarily conducted on 17-28 years old participants. Field test results and their comparisons were conducted on a larger age range. In order to quantify the effect different changes made to the system, the Simulator Sickness Questionnaire was used as a primary metric with user feedback confirming the results. As SSQ is both a subjective metric and is very dependent on a user's inherent motion sickness susceptibility, the Motion Sickness Susceptibility Questionnaire was used to normalize the results. Our findings indicate that MSQ values can be used on SSQ recordings in order to normalize the results across users with varying inherent motion sickness susceptibility. We have also found that a user's motion sickness level increases rapidly in the first 10-20 min of contact with VR and levels out at around 40-50 min. This pattern was best described and approximated with a logarithmic curve. We observed two motion sickness thresholds. Crossing the first was observed to be detrimental to usability and the second one rendered the user unable to continue. In terms of SSQ scores, these values were found to be at around 75-80 and 100-120, respectively. The specific threshold value varied by user due to the subjective nature of SSQ. Repeated exposure proved to have a positive impact on motion sickness, even when the time between different VR sessions was less than the general recovery time. Our tests concluded that a preferable VR setup for an MRSAS application has a FoV between 49-54 deg with a black periphery. Any blurring on the screen or even on the periphery did not have a positive effect on MS.  
Camera-based effects on performance caused by lens distortion or automatic white balance were shown to be negligible, as the primary impact of the effects was concentrated on the overlapping or stitched edges of different camera feeds. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app14062231/s1](https://www.mdpi.com/article/10.3390/app14062231/s1)]([https://www.mdpi.com/article/10.3390/app14062231/s1](https://www.mdpi.com/article/10.3390/app14062231/s1)). Conceptualization, G.A. and R.S. ; methodology, R.E.H. ; software, R.E.H., V.P., T.L. and A.P. ; validation, R.E.H., A.P. and R.S. ; formal analysis, N.M. and V.P. ; investigation, R.E.H., N.M. and V.P. ; resources, R.S., T.L. and A.P. ; data curation, R.E.H. ; writing--original draft preparation, R.E.H. and G.A. ; writing--review and editing, R.E.H. ; visualization, R.E.H. ; supervision, G.A., R.E.H. and R.S. ; project administration, G.A. ; funding acquisition, G.A. All authors have read and agreed to the published version of the manuscript. This research was partially funded by and in cooperation with Vegvisir (Defeng sphere OU). Ethical review and approval were waived for this study, due to this article not containing medical research, no personal data nor identifiable medical data being gathered and all subjects consenting to the experiments prior to putting on the headsets. * [PERSON] et al. (2019) [PERSON]; [PERSON]; [PERSON] Projection displays induce less simulator sickness than head-mounted displays in a real vehicle driving simulator. In Proceedings of the 11 th International Conference on Automotive User Interfaces and Interactive Vehicular Applications, Utrecht, The Netherlands, 21-25 September 2019; pp. 379-387. * [PERSON] and [PERSON] (2020) [PERSON]; [PERSON] Roadvr: Mitigating the effect of vection and sickness by distortion of pathways for in-car virtual reality.