Mathematical Model for Hemodynamic and Intracranial Windkessel Mechanism

The understanding of intracranial system so that one can explain its related pathological condition such as hydrocephalus and traumatic brain injury (TBI) is still subtle. Especially, the cause of hydrocephalus which is known as the common birth defect is not well defined. Traditionally, hydrocephalus was described as imbalance between production and absorption process of cerebrospinal fluid (CSF). However, many recent observations show that the bulk flow theory can no longer explain the cause of hydrocephalus. Hence, the new concept of hydrocephalus has been deviated from the bulk flow theory and comes to focus on the pulsatile dynamic of intracranial system and abnormalities of intracranial Windkessel mechanism. Windkessel mechanism is normally observed in major arterial system as well as intracranial space which is the absorbing function of artery provided by its elastic properties and peripheral resistance. The effectiveness of Windkessel mechanism can convert the pulsatile nature of blood flow generated by cardiac cycle into nearly pulseless outflow to capillary bed. Thus, the simulation via mathematical model based on Windkessel mechanism, which is one of the most useful tool to clarify the pulsatile dynamic within intracranial cavity is proposed. The mathematical model is constructed based on the mechanical and fluid mechanics principles to predict the hemodynamics throughout major arterial system and intracranial space. For intracranial system, the dynamical interaction among major intracranial contents and intracranial pressure (ICP) is simulated. Also, the constraints of Monro-Kellie doctrine is also another requirement to include in this model. To verify the model, the predicted results is compared to clinical data such as MRI data which have a good agreement.Typically, the intracranial disorders are associated with elevated intracranial pressure (ICP) and decreased cerebral blood flow. As the central nervous system (CNS) and brain require the sufficient cerebral blood supply to function normally, a marked reduction of cerebral blood flow known as stroke can result in the brain ischemia and further lead to a failure of brain’s neurological functions. For the patient with traumatic brain injury (TBI), an appearance of unilateral mass lesion such as hematoma is commonly observed. This mass effect can occupy the finite volume of intracranial space which reduces its volume compensatory capacity and brings about interhemispheric asymmetry of ICP and cerebral blood flow. The effect of an appearance of unilateral mass lesion on interhemisperic asymmetry of ICP and cerebral blood flow is also investigated. The significant difference of waveform and timing between two hemispheres is observed. This observation can be used as the indicator to predict and classify the patients with normal or abnormal intracranial Windkessel mechanism which is the useful information for real-time patient monitoring.As mentioned, the reduction of cerebral blood flow is typically observed in the patients with neurosurgical disorders, the medical balloon insertion is introduced as the alternative treatment. To recover the cerebral blood flow, the cadence balloon with inversion cycle provides the most significant improvement in the simulation results which support the possibility of using cadence medical balloon as the treatment options for the patient with decreased cerebral blood flow.According to the simulation results, the failure of intracranial Windkessel mechanism might be the key factor which provide the appropriate explanation to define the cause of hydrocephalus especially communicating hydrocephalus. The developmental cycle of hydrocephalus is also hypothesized. This hypothesis might explore the understanding and direct the effective treatment procedure for the patient who suffers from disorder related to intracranial system.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

EECS - System and Control Engineering

Grantor dc:publisher

Case Western Reserve University School of Graduate Studies

Year dc:date

2013

Author dc:creator

• Sethaput, Thunyaseth

Contributors dc:contributor

• Loparo, Kenneth

• Biomedical Engineering
• Systems Science
• Fluid Dynamics
• Mechanical Engineering
• Intracranial
• Windkessel
• Hemodynamic
• Intracranial Pressure
• ICP
• Hydrocephalus
• TBI
• Monro-Kellie doctrine
• Pulsatility

Statement dc:rights

• unrestricted
• This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.

Language dc:language

English

Repository record dc:identifier

http://rave.ohiolink.edu/etdc/view?acc_num=case1363149368

OAI identifier oai:identifier

oai:etd.ohiolink.edu:case1363149368