The impact of pulsation on the accuracy of simulating flow in coronary artery models

Abstract: Blood flow in the coronary arteries is pulsatile and varies with time. Studies on the blood flow in the coronary arteries are important to aid in the understanding of diseases such as coronary artery disease, which is characterised by a build-up of plaques on the wall of the arteries. These plaques can rupture and cause heart attack or limit the blood flow to the heart muscle resulting in reduced quality of life for the patient. Measurements of pressure are commonly used when classifying the severity of stenoses and are often recorded in simulations used to investigate the haemodynamics of the coronary arteries. A potential to simulate flow as a steady profile instead of the pulsatile profile found in the artery could simplify simulations and in-vivo experiments. In this work, an experimental rig capable of generating pulsatile and steady flow profiles (with the same mean flow rate) was used to generate flow through 3D-printed stenosed coronary arteries. Pressure was measured before and after the stenosed section in each case and the pressure readings were time-averaged for the pulsatile profile. These were used to calculate the pressure drop across each stenosis. Results suggest that for five out of six test cases, the steady flow tests produce a slightly lower pressure drop from the time-averaged pulsatile tests for a range of test cases with stenosis severity from 50-75% area percent occlusion. The largest deviation recorded in the pressure drop for the two flow profiles was approximately 10%. Keywords: biomechanical engineering, pulsatile flow, coronary artery flow behaviour