Arterial pressure wave
= Arterial pressure wave
A small <pressure> disturbance in an elastic artery propagates through the coupled inertia of blood and compliance of the wall. If $\mathcal A$ is the undisturbed area, $\rho$ the <mass density> and $c$ the <wave speed>, the linearized equations give $c^2=\mathcal A/\rho\,dp/d\mathcal A$. A travelling <pressure> amplitude $p_+$ carries flow amplitude $\mathcal A p_+/(\rho c)$; the oppositely travelling wave has the opposite flow sign.