2010-05-12T09:08:49Z2016-04-20T12:12:14Zhttp://oa.upm.es/id/eprint/2533This item is in the repository with the URL: http://oa.upm.es/id/eprint/25332010-05-12T09:08:49ZThe point of maximum curvature as a marker for physiological time seriesWe present a geometric analysis of the model of Stirling. In particular we analyze the curvature of a heart rate time series in response to a step like increment in the exercise intensity. We present solutions for the point of maximum curvature which can be used as a marker of physiological interest. This marker defines the point after which the heart rate no longer continues to rapidly rise and instead follows either a steady state or slow rise. These methods are then applied to find analytic solutions for a mono exponential model which is commonly used in the literature to model the response to a moderate exercise intensity. Numerical solutions are then found for the full model and parameter values presented in Stirling.James StirlingMarĂa S. Zakynthinaki