Experimental Measurement of Pulsatile Blood Pressure in 3D Printed Stenosed Arteries.

Quantification of proximal ($P_{a)}$ and distal $P_{d}$ pressure to arterial stenosis is critical to assess the hemodynamic severity of stenosis via fractional flow reserve ($P_{d}$/$P_{a})$ or trans-stenotic pressure gradient ($P_{a}$-$P_{d})$. Invasive measurement via catheterization requires patient exposure to risk and high medical costs. We built up a pulsatile flow loop, mimicking the blood flow in the human circulatory system, to measure vascular hemodynamics. The loop is equipped with a pulsatile heart pump, elements of resistance and compliance, and measurement devices. The stenosed artery is segmented from computed tomography angiography data, then 3-D printed out and mounted in the loop. The pressure ($P_{a}$ and $P_{d})$ is measured by medical-grade transducers through an in-house built filter/amplifier. The data acquisition system collects pressure and flow-rate signals simultaneously and visualizations are live via LabVIEW. The system can accommodate rigid or flexible 3D printed arteries and real human arteries. The pulsatile flow loop provides a unique capability to validate non-invasive computed pressure and to quantify patient-specific pathophysiological properties of diseased arteries.