Laboratory measurement of blood pressure in human aortoiliac arterial systems via image-based experimental hemodynamics*

Peripheral artery disease is a common circulatory problem in humans, of which iliac arterial stenosis (abnormal lumen reduction) is a significant cause. The narrowed artery reduces blood flow from the heart to the leg. Trans-stenotic pressure gradient (TSPG), defined as a drop of blood pressure before and after the stenosis is an important indicator to determine the severity of blood blockage but obtaining the blood pressure in a diseased artery requires an invasive pressure measurement through catheterization. We have developed a pulsatile flow loop that mimics the blood flow in human circulatory systems, enabling noninvasive measurement of blood pressure in stenosed arteries. The flow loop mainly consists of a mechanical heart pump, resistance valves, compliance elements, pressure transducers, flow meters, and so on. By adjusting the controlling parameters, the flow loop can simulate human cardiovascular conditions. In this work, we develop and validate the laboratory measurement of blood pressure in 3-D printed human aortoiliac arterial systems. Each arterial system is anatomically extracted from a patient’s computed tomography angiography (CTA) data. We study six patient cases with their available blood pressure waveforms invasively measured. We compared the noninvasive pressure measurement with the corresponding invasive measurement. The individual pressure waveforms agree well with each other. Statistical analysis over the six cases with 24 data points achieves a high correlation coefficient of 0.99 with a p-value less than 0.05. We concluded that the experimentally measured blood pressure is reliable.