The Effect of Yoga Meditation and Metronomic Breathing on Physiological Parameters: A Study of Heart Rate Variability

Introduction: Despite the pervading application of different meditation techniques in treating physical and mental ailments, the effects on neuroautonomic function and physiological parameters have not been extensively researched. This study examined some indices from empirical mode decomposition (EMD) of heart rate variability (HRV) signals during meditation. Specifically, this manuscript aimed to evaluate the modes existing in HRV signals during Yoga meditation and compare them with the corresponding indices before Yoga, metronomic and spontaneous breathing. The validity of the HRV was studied using four Yoga meditators, eight healthy subjects, and eight volunteers during metronomic breathing.Material and Methods: Intrinsic mode functions (IMFs) and their power spectrums were characterized utilizing entropy and statistical measures. Moreover, the frequency bands of HRV signals were extracted using wavelet transform to obtain more insight into autonomic differences. Wilcoxon test was used for statistical evaluations.Results: Our results revealed that there are significant differences in very-low-frequency and high-frequency indices between Yoga and other conditions (p < ۰.۰۵). The most variation in IMFs of HRV signals occurred during Yoga, in which the range of six IMF values was between ۱۵ and ۶۳. Additionally, the IMF patterns in both before Yoga and Metronomic breathing were similar. Significantly lower IMF indices were obtained for normal breathing (p < ۰.۰۵). The average wavelet entropy value of IMFs is about ۱۰۶ for metronomic breathing and before Yoga, -۰.۵×۱۰۶ for Yoga, and -۲.۵×۱۰۶ for normal breathing.Conclusion: The proposed EMD-based measures can be efficiently exploited in differentiating the HRV signals of meditators.

Keywords:

Nonlinear Dynamics Heart Rate Wavelet Analysis Meditation , Statistics Nonparametric