Heart-rate data transmission control for vital sensing from densely-located exercisers

Abstract

In this paper, we investigate how to improve the reliability of heart–rate monitoring of a large number of people playing sports over a limited area of sports field. Densely– located nodes attached to exercisers transmit heart–rate data to a data collection node simultaneously, which negatively affects the reliability of data collection due to severe congestions caused by excessive traffic load. In order to solve this problem, we introduce a heart–rate data transmission control scheme where the sensed heart–rate is transmitted only when each node detects a larger variation than a fixed threshold. In order to analyze trade– off between the traffic suppression and increased sensing error through the introduced threshold, we first conduct experiments to obtain heart–rate variations during typical scenarios of exercises in a sports–day at schools in Japan. The obtained experimental data are then used to construct a model of heart–rate variations, which is then employed for computer simulations to evaluate the effectiveness of the introduced heart–rate transmission control. Our numerical results show that the heart–rate transmission control is effective, especially in a scenario where exercisers with different patterns of heart–rate variations coexist.