Smartphone-based Device for Checking Mental Status in Real Time

In this article, we present a smartphone-based device for checking mental status in real time, which for the first time enables real-time check-up of mental status with a smartphone. With this device, by measuring pulse waves, two important mental health indicators can be visualized at the same time: the largest Lyapunov exponent obtained from non-linear analysis of pulse waves, and the autonomic nerve balance. Before the development of this device, the measurement of these indicators had already been conducted in thousands of experiments, and their relationship with individual’s mental status had been intensively studied in recent years. This device enables users to conduct the measurement and capture the mental status dynamically, without the limitation of place and time. It has the potential application in preventing accidents due to failure of emotional management. The device is convenient to use and cost-effective.