Frequency Response of Blood Flow Autoregulation

Autoregulation is the capability of an organ such as the brain, heart, and kidney to maintain a constant blood flow over a series of changes in arterial pressure within their vascular beds. Since the organs in the human body demand a steady delivery of blood and bio–agents to sustain their metabolic activity, autoregulation is crucial in protecting the organs from both over and under perfusion of blood. The impairment of autoregulation may lead to neurological, renal, and other complications. In this study, we analyze a simplified and recently developed mathematical model of blood flow autoregulation based on a system of nonlinear ordinary differential equations. Utilizing this model, we develop the optimal and realistic wall–compliance profiles of the blood vessels. Using the realistic wall–compliance profile, we then find the frequency response of the autoregulation system. The frequency response can be used to determine whether an organ is autoregulating or not given some input frequency.