From Steady to Pulsatile Flow in Molecular Communication: Propagation of Nanoparticles in Mid-Sized Arteries

The interplay of particle propagation due to fluid convection has been subject to extensive research in the areas of molecular communication (MC) and magnetic drug targeting (MDT). Although a lot of models have been developed already, often the time-varying nature of the background flow and the elasticity of the channel walls have been neglected. We propose a simulation-based analysis of particle propagation in the radial artery under pulsatile flow in comparison to classical laminar flow. The effect of elastic channel walls compared to rigid walls is investigated. Our results reveal that in the case of pulsatile flow, the channel impulse response (CIR) is formed by a series of sharp peaks synchronous to the cardiac cycle instead of the long-tailed shape of laminar flow. In particular, 70% of particle movement occurs in the first 30% of each cardiac cycle. The results indicate a strong impact of pulsatile flow on inter-symbol interference and thus the design of demodulation algorithms in MC as well as on the design of steering approaches in MDT.