Wave intensity amplification and attenuation in non-linear flow: Implications for the calculation of local reflection coefficients

Abstract

Local reflection coefficients (R) provide important insights into the influence of wave reflection on vascular haemodynamics. Using the relatively new time-domain method of wave intensity analysis, R has been calculated as the ratio of the peak intensities (RPI) or areas (RCI) of incident and reflected waves, or as the ratio of the changes in pressure caused by these waves (RΔP). While these methods have not yet been compared, it is likely that elastic non-linearities present in large arteries will lead to changes in the size of waves as they propagate and thus errors in the calculation of RPI and RCI. To test this proposition, RPI, RCI and RΔP were calculated in a non-linear computer model ..