Dynamical systems analysis of arterial blood pressure signals in relation to heart rate fluctuations in chick embryos

We attempted a new approach based on a modern dynamical system theory to re construct the arterial blood pressure signals in relation to heart rate flu ctuations of developing chick embryos. The dynamical systems approach in ge neral is to model a phenomenon that is presented by a single time series re cord and approximate the dynamical property (e.g. heart rate fluctuations) of a system based only on information contained in a single-variable (arter ial blood pressure) of the system. The time-series data of the arterial blo od pressure was reconstructed in 3-dimensional space to draw characteristic orbits. Since the reconstructed orbits of the blood pressure should retain information contained in the pressure signals, we attempted to derive inst antaneous heart rate (IHR) from the reconstructed orbits. The derived IHR p resenting HR fluctuations coincided well with the IHR obtained conventional ly from the peak-to-peak time intervals of the maximum blood pressure. Move ments of the reconstructed orbits of the arterial blood pressure in 3-dimen sional space reflected HR fluctuations (i.e. transient decelerations and ac celerations). (C) 1999 Elsevier Science Inc. All rights reserved.