The Research On Mathematical Model Of The Relationship Between Intracranial Pressure And Cerebral Blood Flow

The cerebrovascular diseases seriously threatens the lives of the human health. The clinical research have found that the intracranial pressure (ICP) parameter varies significantly from its normal range in many cerebrovascular diseases. The fluctuation of the ICP could influence the cerebral blood flow (CBF) and cause the cerebral dysfunction. The function of autoregulation of cerebral blood flow could keep the cerebral blood folw at a normal level when the ICP is varies between 5mmHg and 13mmHg.A simulation model of ICP and CBF is discussed based on the cerebrovascular system and the theory of the hemodynamic. The relationship between the arterial resistance and ICP is built through studying the ACBF. The model is improved and computed.Three researches were mainly done as followed:1. The research on the model simulation of the relationship between ICP and CBFThe model of the CBF and cerebrospinal fluid circulation which contains the parameters of ICP, cerebrospinal fluid dynamics, intracranial resistance and cerebral hemodynamics is analysed. Two diodes is add to the model to simulate the unilateralism of the CSF circulation. The ICP curve is painted and can reflect some clinical phenomena.2. The research on the relationship between the arterial resistance and ICPThe model of residual CBF is built based on the theories of hemodynamics and ACBF. The residual CBF is connected with the mean radius of the cerebral blood vessels, the mean arterial blood pressure(CBF), ICP, the length of the artery stenosis according to the simulation when the cerebral infarctio occurs, and mean radius of the cerebral blood vessels is a major influencing factor.By curve fitting to the data of the MABP and ICP, CBF and ICP, CBF and CPP, a function between arterial and ICP is got. The ACBF is embodied by replacing the constant Ra to the function.3. Modify of the model of interaction between ICP and CBFThe model of ICP and CBF is improved and computed using matlab according to the relationship between Ra and ICP. The CBF changing with ICP when the ICP increases by 3mmHg and 1.5mmHg or decreases 3mmHg is studied. Theoretical computation and experimental result show that the model of cerebral blood and cerebrospinal fluid circulation is consistent with the known medicinal facts, and it may offer an auxiliary way for clinical diagnosis of ICP.