title: A multiscale 0-D/3-D approach to patient-specific adaptation of a cerebral autoregulation model for computational fluid dynamics studies of cardiopulmonary bypass.
abstract: Neurological complication often occurs during cardiopulmonary bypass (CPB). One of the main causes is hypoperfusion of the cerebral tissue affected by the position of the cannula tip and diminished cerebral autoregulation (CA). Recently, a lumped parameter approach could describe the baroreflex, one of the main mechanisms of cerebral autoregulation, in a computational fluid dynamics (CFD) study of CPB. However, the cerebral blood flow (CBF) was overestimated and the physiological meaning of the variables and their impact on the model was unknown. In this study, we use a 0-D control circuit representation of the Baroreflex mechanism, to assess the parameters with respect to their physiological meaning and their influence on CBF. Afterwards the parameters are transferred to 3D-CFD and the static and dynamic behavior of cerebral autoregulation is investigated. The parameters of the baroreflex mechanism can reproduce normotensive, hypertensive and impaired autoregulation behavior. Further on, the proposed model can mimic the effects of anesthetic agents and other factors controlling dynamic CA. The CFD simulations deliver similar results of static and dynamic CBF as the 0-D control circuit. This study shows the feasibility of a multiscale 0-D/3-D approach to include patient-specific cerebral autoregulation into CFD studies.
authors.affiliation: Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany. Electronic address: neidlin@hia.rwth-aachen.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Neidlin
authors.affiliation: Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Steinseifer
authors.affiliation: Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Aachen, Germany.
authors.forename: Tim A S
authors.initials: TA
authors.lastname: Kaufmann
mesh_terms: D000777:Anesthetics; D001013:Aorta, Thoracic / Q000502:physiology; D017704:Baroreflex; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002315:Cardiopulmonary Bypass; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003198:Computer Simulation; D006706:Homeostasis; D006801:Humans; D057446:Hydrodynamics; D021621:Imaging, Three-Dimensional; D013997:Time Factors
chemical_list: D000777:Anesthetics
keywords: Baroreflex; Cardiopulmonary bypass; Cerebral autoregulation; Computational fluid dynamics; Lumped parameter