The effect of residual stresses on wave speed in arteries

The traditional approach to calculating stress distribution in arteries has been to assume (incorrectly) that the unloaded intact artery is stress-free. We consider the unloaded intact artery to have initial (i.e. residual) stresses and study how this affects the calculated wave speed of the arterial pulse. We use a set of equations that describe, in a simplified way, the blood flow in arteries and apply nonlinear elasticity theory to derive a formula for wave speed. We compare wave speed calculations under two assumptions (considering unloaded intact arteries as stress-free and considering these arteries to have residual stresses). We find that wave speeds calculated assuming residual stresses are more realistic. Clinical applications of this work are suggested.