[Flow Field Investigation of Prosthetic Heart Valves during In Vitro Durability Testing]

According to the GB/T 12279 series of standards, a flow field test platform for heart valve durability testing was established. A digital particle image velocimetry system was employed to analyze the flow field characteristics of accelerated wear testing (AWT), dynamic failure mode testing (DFM), and real-time wear testing (RWT). The results showed that in AWT, the jet flow in the valve outflow tract appeared as clustered structures. As the frequency increased (from 15 Hz to 20 Hz), the peak flow velocity, peak VSS, and peak RSS all decreased. DFM testing revealed that an increase in pressure gradient (100 mmHg, 140 mmHg, 180 mmHg) was positively correlated with peak flow velocity and peak RSS, while no clear trend was observed for peak VSS. The flow field observed in RWT was closer to physiological conditions, with the jet flow fully developed, showing significant differences from the flow fields in AWT and DFM. A single testing method cannot comprehensively reflect the complex mechanical environment faced by the valve after actual implantation. This study provides a hemodynamic basis for demonstrating the necessity of a comprehensive evaluation of valve durability through AWT, DFM, and RWT.