Globally, 340 million people have blindness or moderate to severe visual impairment (BVI)$^1$ which limits independent outdoor navigation$^2$ and negatively affects their health and quality of life$^{3,4}$. We surveyed 112 people with BVI and found that an ideal outdoor navigation aid must be able to perform turn-by-turn directions, path guidance, and obstacle detection and avoidance. Existing navigation tools such as white canes, guide dogs, and electronic travel aids often lack one or more of these criteria and may be expensive or inaccessible$^{5,6}$. Here we introduce Mobilio, a smartphone application that incorporates machine learning, sensor fusion algorithms, and personalized audio feedback to meet all of the outdoor navigation criteria. The reliability of the smartphone sensors and models used for navigation were assessed with engineering tests in representative navigation scenarios. We performed a series of experiments where Mobilio personalized audio feedback for participants with BVI (n = 14), guided them along an outdoor community path, and helped them navigate an obstacle course. Participants walking with Mobilio and a white cane reduced time to navigate a community path by 13 $\pm$ 3% and environmental contacts by 41 $\pm$ 5% compared to using Google Maps and a white cane. Mobilio achieved similar outdoor navigation reliability as a human guide. Participant surveys reported that Mobilio was easy to use, had a low perceived workload, and provided intuitive audio feedback. This work provides an accessible and personalized tool that may be an effective outdoor navigation aid to increase independence for people with BVI.

翻译：全球有3.4亿人患有失明或中度至重度视力障碍（BVI）$^1$，这限制了其独立户外导航能力$^2$，并对其健康与生活质量产生负面影响$^{3,4}$。我们对112名BVI患者进行调查后发现，理想的户外导航辅助工具需具备turn-by-turn方向指引、路径引导、障碍物检测与规避功能。现有导航工具（如白杖、导盲犬、电子出行辅助设备）往往缺乏上述一项或多项标准，且可能价格昂贵或难以获取$^{5,6}$。本文介绍Mobilio——一款集成机器学习、传感器融合算法与个性化音频反馈的智能手机应用，可满足所有户外导航标准。通过代表性导航场景的工程测试，评估了用于导航的智能手机传感器与模型的可靠性。我们开展系列实验：为BVI参与者（n=14）提供Mobilio个性化音频反馈，引导其沿户外社区路径行走，并协助其穿越障碍赛道。与使用谷歌地图+白杖相比，参与者使用Mobilio+白杖时，社区路径导航时间减少13±3%，环境接触减少41±5%。Mobilio在户外导航可靠性方面达到与人类向导相当的水平。参与者问卷调查显示，Mobilio易于使用、感知工作负荷低，且提供直观的音频反馈。本研究提供了一种可访问的个性化工具，有望成为提高BVI患者独立性的有效户外导航辅助手段。