Purpose

This study proposes a new framework to optimize the design of a transcatheter aortic valve through patient-specific finite element and fluid dynamics simulation.

Methods

Two geometrical parameters of the frame, the diameter at ventricular inflow and the height of the first row of cells, were examined using the central composite design. The effect of those parameters on postoperative complications was investigated by response surface methodology, and a Nonlinear Programming by Quadratic Lagrangian algorithm was used in the optimization. Optimal and initial devices were then compared in 12 patients. The comparison was made in terms of device performance [i.e., reduced contact pressure on the atrioventricular conduction system and paravalvular aortic regurgitation (AR)].

Results

Results suggest that large diameters and high cells favor higher anchoring of the device within the aortic root reducing the contact pressure and favor a better apposition of the device to the aortic root preventing AR. Compared to the initial device, the optimal device resulted in almost threefold lower predicted contact pressure and limited AR in all patients.

Conclusions

In conclusion, patient-specific modelling and simulation could help to evaluate device performance prior to the actual first-in-human clinical study and, combined with device optimization, could help to develop better devices in a shorter period.

中文翻译：

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使用特定于患者的计算机模拟优化经导管心脏瓣膜框架。

目的

本研究提出了一个新框架，通过针对特定患者的有限元和流体动力学仿真来优化经导管主动脉瓣的设计。

方法

使用中心复合设计检查了框架的两个几何参数，即心室流入处的直径和第一排细胞的高度。通过响应面法研究这些参数对术后并发症的影响，并在优化中使用二次拉格朗日算法的非线性规划。然后在 12 名患者中比较了最佳和初始装置。比较是在设备性能方面进行的 [即，减少房室传导系统和瓣周主动脉瓣反流 (AR) 的接触压力]。

结果

结果表明，大直径和高细胞有利于该装置在主动脉根部内的更高锚定，从而降低接触压力，并有利于该装置更好地与主动脉根部并置以防止 AR。与初始设备相比，最佳设备导致所有患者的预测接触压力降低近三倍，并且 AR 有限。

结论

总之，针对特定患者的建模和仿真有助于在实际首次人体临床研究之前评估设备性能，并结合设备优化，有助于在更短的时间内开发出更好的设备。