Estimating coupling directions in the cardio-respiratory system using recurrence properties

TL;DR

This paper introduces a novel method using joint recurrence plots to analyze the directional coupling in the human cardio-respiratory system, revealing specific coupling directions between heart rate, blood pressure, and respiration.

Contribution

First application of recurrence-based coupling direction estimation on experimental cardio-respiratory data, providing new insights into system interactions.

Findings

Respiratory system influences heart rate.

Heart rate influences blood pressure.

No clear coupling detected between blood pressure and respiration.

Abstract

The asymmetry of coupling between complex systems can be studied by conditional probabilities of recurrence, which can be estimated by joint recurrence plots. This approach is applied for the first time on experimental data: time series of the human cardio-respiratory system in order to investigate the couplings between heart rate, mean arterial blood pressure, and respiration. We find that the respiratory system couples towards the heart rate and the heart rate towards the mean arterial blood pressure. However, our analysis could not detect a clear coupling direction between the mean arterial blood pressure and respiration.