Smead Department of Aerospace Engineering Sciences, University of Colorado-Boulder, Boulder, CO, USA.
Human Performance Department, TNO, Soesterberg, The Netherlands.
Exp Brain Res. 2023 Dec;241(11-12):2669-2682. doi: 10.1007/s00221-023-06715-5. Epub 2023 Oct 5.
Entry motion sickness (EMS) affects crewmembers upon return to Earth following extended adaptation to microgravity. Anticholinergic pharmaceuticals (e.g., Meclizine) are often taken prior to landing; however, they have operationally adverse side effects (e.g., drowsiness). There is a need to develop non-pharmaceutical countermeasures to EMS. We assessed the efficacy of a technological countermeasure providing external visual cues following splashdown, where otherwise only nauseogenic internal cabin visual references are available. Our countermeasure provided motion-congruent visual cues of an Earth-fixed scene in virtual reality, which was compared to a control condition with a head-fixed fixation point in virtual reality in a between-subject design with 15 subjects in each group. We tested the countermeasure's effectiveness at mitigating motion sickness symptoms at the end of a ground-based reentry analog: approximately 1 h of 2Gx centrifugation followed by up to 1 h of wave-like motion. Secondarily, we explored differences in vestibular-mediated balance performance between the two conditions. While Motion Sickness Questionnaire outcomes did not differ detectably between groups, we found significantly better survival rates (with dropout dictated by reporting moderate nausea consecutively over 2 min) in the visual countermeasure group than the control group (79% survival vs. 33%, t(14) = 2.50, p = 0.027). Following the reentry analogs, subjects demonstrated significantly higher sway prior to recovery (p = 0.0004), which did not differ between control and countermeasure groups. These results imply that providing motion-congruent visual cues may be an effective mean for curbing the development of moderate nausea and increasing comfort following future space missions.
晕动病（EMS）会影响在适应微重力后返回地球的机组人员。在着陆前，通常会服用抗胆碱能药物（例如，美克洛嗪）；但是，它们会产生操作上的不良反应（例如，嗜睡）。因此需要开发非药物的 EMS 对策。我们评估了一种在溅落时提供外部视觉提示的技术对策的功效，在溅落时，否则只能提供使人恶心的内部舱室视觉参考。我们的对策在虚拟现实中提供了与运动一致的地球固定场景的视觉提示，与虚拟现实中具有固定头点的对照条件进行了比较，每组有 15 名受试者的受试者间设计。我们在基于地面的再入模拟结束时测试了对策减轻晕动病症状的效果：大约 1 小时的 2Gx 离心，随后最多 1 小时的波浪运动。其次，我们探索了两种条件之间前庭介导的平衡性能的差异。虽然运动病问卷的结果在两组之间没有明显差异，但我们发现视觉对策组的存活率明显高于对照组（79%的存活率与 33%的存活率，t（14）= 2.50，p = 0.027）。在进行再入模拟后，受试者在恢复前表现出明显更大的摆动（p = 0.0004），但在对照组和对策组之间没有差异。这些结果表明，提供与运动一致的视觉提示可能是一种有效的方法，可以抑制中度恶心的发展，并在未来的太空任务后提高舒适度。
