Facilitating Text Entry on Smartphones with QWERTY Keyboard for Users with Parkinson’s Disease

Yuntao Wang, Ao Yu, Xin Yi, Yuanwei Zhang, Ishan Chatterjee, Shwetak Patel, Yuanchun Shi

We develop an algorithm that enables users with Parkinson's Disease to type faster and more accurately on QWERTY smartphone keyboards than traditional methods.

Abstract

QWERTY is the primary smartphone text input keyboard confguration. However, insertion and substitution errors caused by hand tremors, often experienced by users with Parkinson’s disease, can severely afect typing efciency and user experience. In this paper, we investigated Parkinson’s users’ typing behavior on smartphones. In particular, we identifed and compared the typing characteristics generated by users with and without Parkinson’s symptoms. We then proposed an elastic probabilistic model for input prediction. By incorporating both spatial and temporal features, this model generalized the classical statistical decoding algorithm to correct insertion, substitution and omission errors, while maintaining direct physical interpretation. User study results confrmed that the proposed algorithm outperformed baseline techniques: users reached 22.8 WPM typing speed with a signifcantly lower error rate and higher user-perceived performance and preference. We concluded that our method could efectively improve the text entry experience on smartphones for users with Parkinson’s disease.