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

Mohammad Tafazzoli-,Nasser Fatouraee,Ali Pashaiee,Mohammad M. Khani,Afshin Anssari-Be

doi:10.3844/ajassp.2008.1730.1736

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 patho- physiological situations such as stenotic arteries and age related stiffening.

Highlights

Hemodynamics plays an important role in understanding the nature of blood flow through the cardiovascular system
Since initiation and development of many cardiovascular diseases have been attributed to hemodynamic parameters, such studies have become of particular importance during the past few years[3,4]
We present a new experimental system which is specially designed and developed to produce original pulsatile blood flow and to detect and measure arterial blood pressure and pressure gradient waves for differing hemodynamic and geometric parameters, including fluid viscosity, wall stiffness, wall dimension and luminal stenosis

Summary

INTRODUCTION

Hemodynamics plays an important role in understanding the nature of blood flow through the cardiovascular system. We present a new experimental system which is specially designed and developed to produce original pulsatile blood flow and to detect and measure arterial blood pressure and pressure gradient waves for differing hemodynamic and geometric parameters, including fluid viscosity, wall stiffness, wall dimension and luminal stenosis. Since this setup is capable of performing under varying viscosity of working fluid along with differing wall stiffness, the resultant data can be used in FSI modeling of circulating fluid with pulsatile flow. With respect to the described characteristics, the proposed experimental setup provides a useful mean to study the hemodynamic parameters, in normal and stenotic conditions

MATERIALS AND METHODS

RESULTS AND DISSCUSION

CONCLUSION