Analysis of lagged Poincaré plots in heart rate signals during meditation

In heart rate analysis, the width of Poincaré plots can be considered as a criterion of short-term variability in signals. The aim of this study is to evaluate the effect of different lags on the width of the Poincaré plots in heart rate signals during meditation. For this purpose, we used heart rate signals available in Physionet database. Poincaré plots with six different lags (1–6) were constructed for two sets of data and the width of the Poincaré plot for each lag was calculated. The results show that during meditation the width of Poincaré plot tended to increase as the lag increased. During meditation, the width of Poincaré plot with lag-1 was 2.2±0.6 and with lag-6 was 7.3±1.7. The simplicity of the width of Poincaré plot calculation and its' adaptation to the chaotic nature of the biological signals could be useful to evaluate heart rate signals during meditation.