A new concept of assistive virtual keyboards based on a systematic review of text entry optimization techniques

Abstract Introduction: Due to the increasing popularization of computers and the internet expansion, Alternative and Augmentative Communication technologies have been employed to restore the ability to communicate of people with aphasia and tetraplegia. Virtual keyboards are one of the most primitive mechanisms for alternatively entering text and play a very important role in accomplishing this task. However, the text entry for this kind of keyboard is much slower than entering information through their physical counterparts. Many techniques and layouts have been proposed to improve the typing performance of virtual keyboards, each one concerning a different issue or solving a specific problem. However, not all of them are suitable to assist seriously people with motor impairment. Methods: In order to develop an assistive virtual keyboard with improved typing performance, we performed a systematic review on scientific databases. Results: We found 250 related papers and 52 of them were selected to compose. After that, we identified eight essentials virtual keyboard features, five methods to optimize data entry performance and five metrics to assess typing performance. Conclusion: Based on this review, we introduce a concept of an assistive, optimized, compact and adaptive virtual keyboard that gathers a set of suitable techniques such as: a new ambiguous keyboard layout, disambiguation algorithms, dynamic scan techniques, static text prediction of letters and words and, finally, the use of phonetic and similarity algorithms to reduce the user's typing error rate.

摘要与引言：随着计算机的不断普及与互联网的持续拓展，辅助与替代沟通（Alternative and Augmentative Communication，AAC）技术被用于恢复失语症与四肢瘫痪患者的沟通能力。虚拟键盘是最为基础的文本替代输入机制之一，在完成该类辅助沟通任务中发挥着关键作用。然而这类虚拟键盘的文本输入速度远低于实体物理键盘。已有诸多技术与布局方案被提出以提升虚拟键盘的输入性能，各类方案针对不同问题或解决特定痛点，但并非所有方案都适用于辅助存在严重运动功能障碍的用户。
方法：为开发一款输入性能优化的辅助虚拟键盘，本研究针对学术数据库开展了系统性综述。
结果：本研究共检索到250篇相关文献，最终筛选纳入52篇。随后我们明确了虚拟键盘的8项核心特征、5种优化数据输入性能的方法，以及5项用于评估输入性能的指标。
结论：基于本次综述，本研究提出一款辅助型、优化型、紧凑型且自适应的虚拟键盘概念，其集成了一系列适配的技术方案，包括：新型歧义化键盘布局、歧义消解算法、动态扫描技术、字母与单词静态文本预测，最终通过语音与相似度算法降低用户的输入错误率。