Electronic Phantom for Wall Shear Rate Emulation

In an artery, the Wall Shear Rate (WSR) represents the blood velocity derivative along the radial direction, evaluated near the vessel wall. WSR has been proven a parameter of high medical importance in the monitoring and prediction of cardiovascular diseases. Its measurement, obtained through echographs, is quite challenging since both wall position and blood velocity distribution are simultaneously needed. Several methods have been proposed so far, but the evaluation of their performance is not straightforward: tests on volunteers do not allow a comparison to a ground-truth and are not reproducible, flow phantoms do not reproduce real-like conditions accurately and, anyhow miss an accurate ground-truth as well. This work presents an Electronic Phantom (EP) specifically optimized for the emulation of the WSR. The EP reproduces towards the probe of the echograph under test an ultrasound signal that emulates the echoes from both the artery wall and the blood. The wall/blood configuration is arbitrarily programmed by the user. The echograph performs the WSR measurement like it was investigating a real vessel, with the advantage that the measurement can be compared to a perfectly known and programmable ground-truth.