人工心脏瓣膜体外耐久性试验流场研究

      Hemodynamic Characterization of Transcatheter Prosthetic Heart Valves in In Vitro Flow Field Testing

      • 摘要: 根据GB/T 12279系列标准搭建人工心脏瓣膜耐久性试验条件下的流场试验平台,运用数字粒子图像测速系统分析加速磨损试验(accelerated wear testing,AWT)、动态失效模式试验(dynamic failure mode testing,DFM)及实时磨损试验(real-time wear testing,RWT)的流场特征。研究结果显示AWT试验中瓣膜流出道射流呈团状,随频率升高(15 Hz至20 Hz),峰值流速、VSS峰值和RSS峰值均降低;DFM试验显示压力梯度增加(100 mmHg、140 mmHg、180 mmHg)与峰值流速及RSS峰值呈正相关,VSS峰值无显著规律;RWT试验所观察到的流场更接近生理状态,射流充分发展,与AWT和DFM试验的流场存在显著差异,单一试验均无法全面反映瓣膜在实际植入环境中所面临的复杂力学环境。本研究为论证AWT、DFM和RWT对瓣膜耐久性进行综合评估的必要性提供了相关血流动力学依据。

         

        Abstract: 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.

         

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