Power Spectral Densities of Temporal Variations of Blood Pressures

Abstract

A comprehensive study of power spectral densities for time series data of blood pressure measured for four individuals, one healthy subject and three diseased subjects (pure autonomic failure (PAF), PAF complicated with supraventricular premature contraction, and multiple cerebral infarction with atrial fibrillation (Af)), was carried out using the computing program “MemCalc.” The whole spectrum for every time series indicates exponential characteristics until it levels off at a limit determined by the accuracy of the present measurement. The three-dimensional spectral array obtained from segment time series analysis showed a fine array of the fundamental and its harmonic modes, and was concluded to be a powerful tool for medical diagnosis. “Homeostasis” in living bodies is discussed on the basis of the present results. A new link between the nonlinear sciences and basic and/or clinical medicine found in the present study is sure to play an important role in medical diagnosis and prognosis.