Flow Disturbance by Catheter‐Based Bio‐MEMS Sensors in Arterial Circulation

Catheter‐based micro electro mechanical system (MEMS) sensors provide the spatial and temporal resolution for real‐time monitoring in the vasculature. However, the positioning and size of the catheter influence the local velocity field in the blood vessels. We develop a Computational fluid dynamics (CFD) simulation to assess and design the micro sensors with optimal accuracy and minimal flow disturbance in the rabbit aorta. Methods and Results: The 3‐D straight geometry and mesh were first created in GAMBIT by using dimensions of the rabbit aorta; and the simulation was done by the FLUENT®. Properties such as mean velocity, fluid viscosity, density, and Reynolds numbers were determined to simulate the physiological parameters in the rabbit aorta. Simulation was based on steady, incompressible, laminar flow of Newtonian fluid. Three catheter positions along with various diameters were assessed. A minimal flow disturbance occurred if the catheter with a diameter of 0.22 mm was touching the vessel wall. The disturbance developed as the catheter was moved towards the center of the aorta. When the catheter was positioned in the center, the disturbance on the arterial wall was reduced. Conclusion: Our findings provide a basis to determine the size of MEMS catheter and to minimize flow disturbance by positioning the catheter near the wall. We will be able to develop an empirical solution to correlate the shear stress measurements on the catheter surface with those on the blood vessel wall. 1Velocity profiles inside the blood vessel2Shear stress on the vessel wall and catheter surface