A New System to Analyze Pulsatile Flow Characteristics in Elastic Tubes for Hemodynamic Applications

Abstract

In this research, we present a new designed experimental setup for study of characteristics of pulsatile flow in elastic tubes, aiming to simulate arterial blood flow. This system includes four major components: (1) a pulsatile pump producing original arterial flow, (2) an elastic element to simulate coupling of the heart with the arterial system, (3) an elastic tube with mechanical characteristics of the arterial wall and assembly of pressure transducers to monitor inlet and outlet pulsatile pressures and the resultant pulsatile pressure gradient and (4) a resistant element to simulate peripheral resistant distal the artery. The system is capable of performing under different mechanical conditions, including tubes with different elastic moduli and fluids with different viscosities. Experimental results showed a precise ability of producing original blood flow waves and recording pressure pulses and pressure gradient waves under different mechanical conditions. The resultant pressure pulses were compatible with the diastolic-systolic pressure pulses of typical arteries. The system showed an accurate sensitivity to variations of fluid viscosity and elasticity of tube wall. Experimental results showed that stiffening of the wall resulted in decrease of mean pressure gradient pulse. Results also showed that an elevated fluid viscosity led to a higher mean value of pressure gradient and less fluctuation of pressure gradient pulse. Results are in good agreement with theoretical considerations of higher energy dissipation and consequent pressure drop by increased fluid viscosity. The designed experimental setup might be used in evaluation of hemodynamic parameters in pathophysiological situations such as stenotic arteries and age related stiffening.