An experimental model to simulate arterial pulsatile flow: in-vitro pressure and pressure gradient wave study

A new experimental model developed to simulate arterial pulsatile flow is presented in this paper. As a representative example, the flow characteristics and the properties of brachial artery were adopted for the purpose of this study. With the physiological flow of the human brachial artery as the input, the pressure and pressure gradient waves under healthy and different scenarios mimicking diseased conditions were simulated. The diseased conditions include the increase in blood viscosity (reflecting the elevation of hematocrit), stiffening of the arterial wall, and stiffening of the aortic root as the coupling between the heart and arterial tree, presented by the Windkessel element in the setup. Each of these conditions resulted in certain effects on the propagation of the pressure and pressure gradient waves, as well as their patterns and values, investigated experimentally. The results suggest that the pressure wave dampens at arterial sites with higher hematocrit, while the stiffening of the Windkessel element elevated the diastolic pressure, and lowered the pressure drop, similar to the results observed by stiffening the arterial wall. Based on these results, it is hypothesised that the cardiovascular system may not function within the minimum energy consumption criterion, contrary to some other physiological functions.