Computational Fluid Dynamics (CFD) Simulation for the Extraction of Blood Clot in Middle Cerebral Artery using ‘GP’ 2 Device

Stroke has become the number three killer disease in Malaysia following heart disease and cancer; with 110 of people dying from it every day. The effects of stroke often lead to life-changing, permanent impairment to the patients such as paralysis, speech and logic sequencing. Hence, recent studies are looking into stroke treatments with minimal after surgical effect to patients. One of the alternatives is using mechanical thrombectomy devices. In this project, the simulation for ‘GP’ 2 device which functions to extract the blood clot in the artery without damaging the arterial wall and causing downstream embolism is presented. The simulation will be carried out using computational fluid dynamics; applying the Volume of Fluid (VOF) model.
In grid size selection, it is clear that finer grids results in higher accuracy calculations i.e. better results. However, this is achieved at the cost of prolonged computational time. From grid sensitivity study in identifying the optimum grid size that is fine enough to generate accurate calculations but large enough to avoid extra computational time; the grid size of 0.2mm is used.
The design for ‘GP’ 2 Device has to be characterised to identify which of the two proposed designs is efficient for the suction of blood clot for 100% occlusion in the Middle Cerebral Artery. Design for ‘GP’ 2 Model 1 device is better at clot extraction than the Model 2 device because increase in surface area for suction favours same-suction principle rather than vortex creation to break the clot. Theoretically, higher pressure results in faster clot extraction. However, the value of pressure applied shall be observed closely so that no arterial damage is done and it can be applied for clinical tests. For both models, it can be shown that higher pressure extracts blood clot at lower time whereby the fastest clot extraction occurs at time 0.00498s for Model 1, and 0.01211s for Model 2 both at 60 kPa.