虚拟现实增强步行在脑卒中后患者中的应用：视景速度和沉浸水平对步态生物力学的影响。

Virtual reality-enhanced walking in people post-stroke: effect of optic flow speed and level of immersion on the gait biomechanics.

机构信息

Rehabilitation Research, Department of Physiotherapy, Human Physiology and Anatomy, Vrije Universiteit Brussel, Brussels, Belgium.

Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium.

出版信息

J Neuroeng Rehabil. 2023 Sep 25;20(1):124. doi: 10.1186/s12984-023-01254-0.

DOI:10.1186/s12984-023-01254-0

PMID:37749566

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC10518929/

Abstract

BACKGROUND

Optic flow-the apparent visual motion experienced while moving-is absent during treadmill walking. With virtual reality (VR), optic flow can be controlled to mediate alterations in human walking. The aim of this study was to investigate (1) the effects of fully immersive VR and optic flow speed manipulation on gait biomechanics, simulator sickness, and enjoyment in people post-stroke and healthy people, and (2) the effects of the level of immersion on optic flow speed and sense of presence.

METHODS

Sixteen people post-stroke and 16 healthy controls performed two VR-enhanced treadmill walking sessions: the semi-immersive GRAIL session and fully immersive head-mounted display (HMD) session. Both consisted of five walking trials. After two habituation trials (without and with VR), participants walked three more trials under the following conditions: matched, slow, and fast optic flow. Primary outcome measures were spatiotemporal parameters and lower limb kinematics. Secondary outcomes (simulator sickness, enjoyment, and sense of presence) were assessed with the Simulator Sickness Questionnaire, Visual Analogue Scales, and Igroup Presence Questionnaire.

RESULTS

When walking with the immersive HMD, the stroke group walked with a significantly slower cadence (-3.69strides/min, p = 0.006), longer stride time (+ 0.10 s, p = 0.017) and stance time for the unaffected leg (+ 1.47%, p = 0.001) and reduced swing time for the unaffected leg (- 1.47%, p = 0.001). Both groups responded to the optic flow speed manipulation such that people accelerated with a slow optic flow and decelerated with a fast optic flow. Compared to the semi-immersive GRAIL session, manipulating the optic flow speed with the fully immersive HMD had a greater effect on gait biomechanics whilst also eliciting a higher sense of presence.

CONCLUSION

Adding fully immersive VR while walking on a self-paced treadmill led to a more cautious gait pattern in people post-stroke. However, walking with the HMD was well tolerated and enjoyable. People post-stroke altered their gait parameters when optic flow speed was manipulated and showed greater alterations with the fully-immersive HMD. Further work is needed to determine the most effective type of optic flow speed manipulation as well as which other principles need to be implemented to positively influence the gait pattern of people post-stroke.

TRIAL REGISTRATION NUMBER

The study was pre-registered at ClinicalTrials.gov (NCT04521829).

摘要

背景

在跑步机上行走时，人们会体验到视动流（即运动时的视觉运动），但跑步机上不存在视动流。借助虚拟现实（VR），人们可以控制视动流，从而改变行走方式。本研究旨在调查：（1）完全沉浸式 VR 和视动流速度控制对脑卒中患者和健康人的步态生物力学、模拟器不适和愉悦感的影响；（2）沉浸水平对视动流速度和存在感的影响。

方法

16 名脑卒中患者和 16 名健康对照者进行了两次 VR 增强跑步机行走测试：半沉浸式 GRAIL 测试和完全沉浸式头戴式显示器（HMD）测试。两个测试均包括 5 次行走测试。在两次适应测试（无 VR 和有 VR）后，参与者在以下三种条件下进行了 3 次行走测试：匹配、慢和快视动流。主要结局测量指标是时空参数和下肢运动学。次要结局（模拟器不适、愉悦感和存在感）通过模拟器不适问卷、视觉模拟量表和 Igroup 存在感问卷进行评估。

结果

当使用沉浸式 HMD 行走时，脑卒中组的步频明显变慢（-3.69 步/分钟，p=0.006），步幅时间延长（+0.10 秒，p=0.017），未受影响的腿站立时间延长（+1.47%，p=0.001），未受影响的腿摆动时间减少（-1.47%，p=0.001）。两组都对视动流速度的变化做出了反应，即视动流速度变慢时人们会加速，视动流速度变快时人们会减速。与半沉浸式 GRAIL 测试相比，使用完全沉浸式 HMD 来控制视动流速度对视动流速度对步态生物力学的影响更大，同时也产生了更高的存在感。

结论

在跑步机上行走时增加完全沉浸式 VR，会导致脑卒中患者的步态模式更加谨慎。然而，使用 HMD 行走是可以耐受和愉悦的。当视动流速度发生变化时，脑卒中患者会改变他们的步态参数，并且在使用完全沉浸式 HMD 时，会发生更大的变化。还需要进一步的研究来确定最有效的视动流速度控制类型，以及需要实施哪些其他原则来积极影响脑卒中患者的步态模式。