Virtual keyboards could potentially replace traditional physical keyboards for text input and human-computer-interface due to their portability and comfortable usage characteristics. However, typical virtual keyboards such as wearable keyboards and camera-based keyboards have unsatisfactory input recognition accuracy, and hence, preventing them from gaining pervasive acceptance by users. In this study, we demonstrated that the layout optimization of keyboards can potentially improve recognition accuracy for ring-type motion sensing virtual keyboards, and analyzed several layout designs for the configuration of typing keys. Moreover, we proved that the new layout designs have significant advantages in reducing muscle oppression for the users. The layout designs were mainly improved through three aspects: arc and split design, key position adjustment, and letter arrangement. Three new layouts were tested, which show significant improvements ranging from 5.74% to 7.51% in recognition accuracy, i.e., achieving up to 97.57% accuracy for ring-type virtual keyboards. Additionally, muscle oppression test results (using surface myoelectricity data) indicate that our new keyboard layouts could provide a significant difference ( $\text{p}< 0.05$ ) in reducing muscle oppression from traditional QWERTY keyboards. As for the moving distance of finger tips, our customized layouts could even reduce half of the movement distance compared with traditional keyboards. The experimental results demonstrate that our motion sensing rings combined with customized keyboard layouts could greatly overcome several disadvantages of traditional QWERTY keyboards.

中文翻译：

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基于布局再设计的高精度定制环形虚拟键盘

由于其便携性和舒适的使用特性，虚拟键盘有可能取代传统的物理键盘用于文本输入和人机界面。然而，典型的虚拟键盘，如可穿戴键盘和基于摄像头的键盘，其输入识别准确度并不令人满意，因此阻碍了它们被用户普遍接受。在这项研究中，我们证明了键盘的布局优化可以潜在地提高环形运动感应虚拟键盘的识别精度，并分析了几种键入键配置的布局设计。此外，我们证明了新的布局设计在减少用户肌肉压迫方面具有显着优势。版面设计主要通过三个方面进行改进：圆弧和分体设计，键位调整，字母排列。测试了三种新布局，显示识别准确率从5.74% 到7.51% 的显着改进，即实现了环形虚拟键盘的高达97.57% 的准确率。此外，肌肉压迫测试结果（使用表面肌电数据）表明我们的新键盘布局可以提供显着差异（ $\text{p}< 0.05$ ) 减少来自传统 QWERTY 键盘的肌肉压迫。至于指尖的移动距离，我们定制的布局甚至可以比传统键盘减少一半的移动距离。实验结果表明，我们的运动感应环结合定制的键盘布局可以极大地克服传统 QWERTY 键盘的几个缺点。