Heart Rate Variability Analysis for Typing Tasks with Different Keyboard Features

Office works such as typing can be used as a stressor in mental stress experiments. With different settings of task condition variant levels of stress can be induced, and the consequent responses and changes in autonomic nervous system (ANS) can be monitored/measured with bio-signal data. Since typing is a common work in the scenarios of office situations, it is expected that one can incorporate stress-induction typing tests in daily works to realize a test in-the-wild approach for studies of mental health. The present paper introduces results of heart rate variability (HRV) analysis for experimental data acquired in tests of typing tasks with different keyboard features. In this study, the keyboard features are set with combinations of two pairs of key switches and three task levels, where the task levels are achieved with key swapping. In order to check rapid and abrupt changes of stress level, (ultra) short-term HRV analysis is considered with the evaluation windows shorter than 60 s. Results of the HRV analysis depict variations in HRV indices according to typing texts and the keyboard features as experimental condition. In addition, statistical investigation of these HRV indices is used to compare between the experimental conditions.