Lumped model of healthy cerebrovascular system during cardiac cycle

Several diseases in the intracranial system may befollowed by some serious disorderliness such as the brainhydrocephalus and Alzheimer problems. Due to the brain systemsensitivity, performing invasive experiments cannot be effective tostudy the system alterations; or overcoming the measurementlimits. Here, the lumped-parameter compartmental flow model ofthe cerebrovascular system was used. This model was consisted ofseveral compartments including extracranial arteries, intracranialarteries and extracranial veins, intracranial veins, capillaries,venous sinus, cerebrospinal fluid circulation in ventricles, cranialsubarachnoid space and spinal subarachnoid spaces. Thecompartments were modeled with constant compliances andresistances that the behavior of each of which was represented bythe pressure and single fluid discharge parameters, both were thefunction of time but not of space. Blood and cerebrospinal fluidwere the fluids flowing in the compartments of the model whichhad the same physical properties and were assumed to beNewtonian and incompressible. Mass and momentum balance ledto eight ordinary differential equations containing eight unknownpressure parameters. The arterial pressure of the healthy man asa sinusoidal pressure with physiological conditions were used asthe input data in model. System validating was performed by usingthe experimental data of arterial flowrate, flowrate in aqueductsylvius and spinal canal which were constructed from the phasecontrastmagnetic resonance images. Finally, it was observed thatthere was a good agreement between the numerical and theexperimental results.

کلیدواژه ها:

lumped model ، cerebrospinal fluid ، resistance ، compliance ، intracranial space