New methods for controlling cerebral aneurysms with Reynolds Number and Shear stress: Literary review

Dr.  Allal Assia,  Mechanical Engineering Departement, National Polytechnic School Maurice Audin , Oran,  Algeria

Dr. Habchi Nawel , National hospital for Neurology and Neurosurgery (NHNN) and University of Victoria London, United Kingdom

Abstract:

An aneurysm is a pathology where a blood vessel dilates abnormally due to a weakness in the vessel's wall. Brain aneurysms result in swelling in the form of a sac, usually in the most fragile arteries. Ruptured brain aneurysms are the most common cause of subarachnoid hemorrhage, a stroke less common than ischemic strokes. This study aims to study the Reynolds number and shear stress for blood flow, as fluid flow is characterized by these parameters. The Reynolds number can identify the region where the flow is laminar, transient, or turbulent, while the shear stress measures the force exerted at the artery wall level.

Blood flow is classified into laminar flow and turbulent flow based on the Reynolds number value. Laminar flow admits symmetrical and parallel current lines, while turbulent flow is characterized by spatiotemporal fluctuations of current lines leading to vortic-like phenomena. The results indicate that blood flow is transient before and after an aneurysm and becomes turbulent inside the aneurysm. Shear stresses are equal to the pressure, which varies little compared to the patient's pressure but increases as blood pressure increases.

Keywords: Brain aneurysm, Reynolds number, Shear stress