发表机构
Google（谷歌）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
针对双手忙碌场景下的免手持 XR 交互问题，提出基于 spare 关节招募的动态机会型身体输入技术 DOBI，经实验验证其控制性能良好且可用性高。
AI 中文摘要
扩展现实（XR）系统在用户进行持续体力任务时往往最有用，但当前的交互技术仍在很大程度上假设双手可用。我们提出机会型身体输入这一交互范式，它可将连续的 XR 控制重定向到当下空闲的任意身体区域。为研究用户如何自然协调这些 spare 身体动作，我们在 6 种双手忙碌场景中开展了诱导研究。我们发现，虽然用户偏好的 spare 身体区域会根据物理约束动态变化，但产生的自发动作共享围绕主导主轴组织的一致低维运动学结构。基于这些发现，我们提出 DOBI（Dynamic Opportunistic Body Input，动态机会型身体输入），这是一种实时 XR 技术，它利用目光瞄准 UI 元素，通过简短触发手势识别被招募的 spare 身体区域，再利用该区域的后续运动驱动连续的一维控制。一项一维菲茨定律（Fitts' law）研究确立了该范式在 4 种不同身体区域的基线运动性能，实现了最高 2.62 比特/秒的吞吐量，总体错误率为 5.0%；一项双任务可用性研究表明，DOBI 在用户进行真实的双手忙碌活动时，支持可靠、低 effort 的控制，系统可用性量表（SUS）得分为 84.2。
英文摘要
Extended Reality (XR) systems are often most useful when users are engaged in ongoing physical tasks, yet current interaction techniques still largely assume the hands are available. We present opportunistic body input, an interaction paradigm that redirects continuous XR control to whichever available body region remains free in the moment. To investigate how users naturally coordinate these spare-body movements, we conducted an elicitation study across six hand-busy scenarios. We found that while users' preferred spare body regions shift dynamically based on physical constraints, the resulting spontaneous movements share a consistent, low-dimensional kinematic structure organized around a dominant principal axis. Building on these findings, we present DOBI (Dynamic Opportunistic Body Input), a real-time XR technique that uses gaze to target a UI element, a brief trigger gesture to identify the recruited spare body region, and the region's subsequent motion to drive continuous 1D control. A 1D Fitts' law study establishes the baseline motor performance of this paradigm across four distinct body regions, achieving throughputs up to 2.62 bits/s with an overall 5.0% error rate, and a dual-task usability study shows that DOBI supports reliable, low-effort control (SUS = 84.2) while users remain engaged in realistic hand-busy activities.
Comments14 pages, 12 figures. To appear in the 39th Annual ACM Symposium on User Interface Software and Technology (UIST '26), November 2-5, 2026, Detroit, MI, USA
