School of Mechanical Engineering, Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, Jiangsu, China.
Modern Education Technology Center, Henan University of Economics and Law, Zhengzhou 450046, China.
Comput Methods Programs Biomed. 2024 Apr;246:108063. doi: 10.1016/j.cmpb.2024.108063. Epub 2024 Feb 10.
Self-expanding polymer braided stents are expected to replace metallic stents in the treatment of Peripheral Arterial Disease, which seriously endangers human health. To restore the patency of blocked peripheral arteries with different properties and functions, the radial supporting capacity of the stent should be considered corresponding to the vessel. A theoretical model can be established as an effective method to study the radial supporting capacity of the stent which can shorten the stent design cycle and realize the customization of the stent according to lesion site. However, the classical model developed by Jedwab and Clerc of radial force is only limited to metallic braided stents, and the predictions for polymer braided stents are deviated.
In this paper, based on the limitation of the J&C model for polymer braided stents, a modified radial force model for polymer braided stents was proposed, which considered the friction between monofilaments and the torsion of the monofilaments. And the modified model was verified by radial force tests of polymer braided stents with different structures and monofilaments.
Compared with the J&C model, the proposed modified model has better predictability for the radial force of polymer braided stents that prepared with different braided structure and polymer monofilaments. The root mean squared error of modified model is 0.041±0.026, while that of the J&C model is 0.246±0.111.
For polymer braided stents, the friction between the polymer monofilaments and the torsion of the monofilaments during the radial compression cannot be ignored. The radial force prediction accuracy of the modified model considering these factors was significantly improved. This work provides a research basis on the theoretical model of polymer braided stents, and improves the feasibility of rapid personalized customization of polymer braided stents.
自膨聚合物编织支架有望替代金属支架治疗外周动脉疾病，这种疾病严重危害人类健康。为了恢复不同性质和功能的阻塞性外周动脉的通畅性，支架的径向支撑能力应与血管相对应。建立理论模型可以作为研究支架径向支撑能力的有效方法，从而缩短支架设计周期，并根据病变部位实现支架的定制化。然而，Jedwab 和 Clerc 开发的经典径向力模型仅局限于金属编织支架，对聚合物编织支架的预测存在偏差。
本文针对聚合物编织支架的 J&C 模型的局限性，提出了一种改进的聚合物编织支架径向力模型，该模型考虑了单丝之间的摩擦力和单丝的扭转。通过对不同结构和单丝的聚合物编织支架的径向力测试对改进模型进行了验证。
与 J&C 模型相比，提出的改进模型对不同编织结构和聚合物单丝制备的聚合物编织支架的径向力具有更好的预测能力。改进模型的均方根误差为 0.041±0.026，而 J&C 模型的均方根误差为 0.246±0.111。
对于聚合物编织支架，在径向压缩过程中聚合物单丝之间的摩擦力和单丝的扭转不容忽视。考虑这些因素的改进模型的径向力预测精度显著提高。这项工作为聚合物编织支架的理论模型提供了研究基础，提高了聚合物编织支架快速个性化定制的可行性。
