Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop

TL;DR

This study applies detrended fluctuation analysis to blood pressure data in rats, revealing changes in control dynamics and adaptation after surgical disruption, and proposes a model based on opposing neural forces.

Contribution

It introduces a novel application of DFA to blood pressure regulation, identifying crossover phenomena and modeling the feedback control as a balance of nonlinear antagonistic forces.

Findings

Identified crossover between two scaling regions in blood pressure signals.

Observed adaptation in blood pressure regulation dynamics post-surgery.

Proposed a simple nonlinear model reproducing DFA crossover features.

Abstract

We use detrended fluctuation analysis (DFA) to study the dynamics of blood pressure oscillations and its feedback control in rats by analyzing systolic pressure time series before and after a surgical procedure that interrupts its control loop. We found, for each situation, a crossover between two scaling regions characterized by exponents that reflect the nature of the feedback control and its range of operation. In addition, we found evidences of adaptation in the dynamics of blood pressure regulation a few days after surgical disruption of its main feedback circuit. Based on the paradigm of antagonistic, bipartite (vagal and sympathetic) action of the central nerve system, we propose a simple model for pressure homeostasis as the balance between two nonlinear opposing forces, successfully reproducing the crossover observed in the DFA of actual pressure signals.