Periodic heart rate decelerations in premature infants
A normal healthy heart beats at a variable rate with extraordinarily complex fluctuations across a wide range of time scales. Reduced complexity of heart rate has both clinical and dynamical significance - it may provide warning of impending illness, or clues about the dynamics of the heart's pacemaking system. In work published in the April issue of Experimental Biology and Medicine, simple and interesting heart rate dynamics in premature human infants is reported - reversible transitions to large-amplitude periodic oscillations - and the appearance and disappearance of these periodic oscillations is described by a simple mathematical model, called a Hopf bifurcation. The work was carried out by Abigail Flower, as part of her PhD thesis in biophysics, working together with Randall Moorman and Douglas Lake at the University of Virginia, and John Delos, at the College of William and Mary...