Stress Evaluation with Biometric Information Using Smartphone by Radio Wave Reflection

Smartphone can be used to operate IoT devices and access services such as smartphone game, but prolonged use cause gaming disorder. Gaming disorder was published as an international disease in 2022 by World Health Organization (WHO). Gaming disorder is a symptom of an inability to control the amount of time spent playing games daily. In recent years, the number of patients with gaming disorder has been increasing and there are not enough hospitals to treat them, so it is necessary to cure gaming disorder by oneself without visiting hospitals. Therefore, it is necessary to understand the stress that users are under while playing games, and to provide remedial measures such as encouraging rest within a reasonable range. Since this paper is an initial study, stress evaluation of users during smartphone game playing. To evaluate the stress using biometric information, we obtain temporal changes in radio wave intensity by reflecting radio waveform in the 2.4 GHz band to the chest, and pulse wave and respiration waveforms by signal processing, from which 17 parameters that are attributable to stress. From the one-month smartphone usage logs, 16 subjects with short average game time per month and 18 subjects with long average game time per month are extracted. Since it can be assumed that the stress state during game play differs between the groups with short and long average game time, comparison of the difference in variation during game play using stress-induced parameters and binary classification using machine learning to evaluate the user's stress state. Since this method uses two antennas in the 2.4GHz band, it will be possible to measure stress using smartphones in the future, contributing to the understanding of stress that is likely to be held unconsciously.