Mimicking of the Human Regulatory System by Flow-Dependent Vascular Resistance: A Feasibility Study

Neurologic malfunction occurs frequently during the use of extracorporeal circuits. This is related to the flow in the cardiovascular system and has been investigated in recent studies. Cerebral autoregulation plays an important role in ensuring sufficient perfusion of the human brain, especially during non-physiological flow conditions. However, it has been neglected in those studies. In this work, a mathematical model to mimic the human regulatory system is developed and implemented in a computational fluid dynamics model that was validated by means of particle image velocimetry. The mathematical model consists of flow-dependent vascular resistances which are adjusted for each vessel distinctively. This is achieved by assuming a polynomial correlation between the flow to each vessel and the vascular resistance. Using these assumptions, physiological flow as well as the application of cardiopulmonary bypass can be simulated with feasible results. However, the level of autoregulation must be investigated in further studies.