A layer-specific three-dimensional model for the simulation of balloon angioplasty using magnetic resonance imaging and mechanical testing
A layer-specific three-dimensional model for the simulation of balloon angioplasty using magnetic resonance imaging and mechanical testing
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DOI：
10.1114/1.1492812
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发表时间：
2002-06-01
影响因子：
3.8
通讯作者：
Schulze-Bauer, CAJ
中科院分区：
文献类型：
--
作者：
Holzapfel, GA;Stadler, M;Schulze-Bauer, CAJ
详细了解球囊血管成形术的机械过程需要三维（3D）建模和有效的数值模拟。我们开发了与特定机械反应相关的8种不同动脉成分的3D模型。三维几何模型基于人死后狭窄动脉的体外磁共振成像，用非均匀有理b样条曲面表示。相应维管组织的力学试验为大应变本构规律的建立提供了基础，该大应变本构规律模拟了超生理载荷下典型的各向异性、高度非线性和非弹性的力学特性。三维有限元实现考虑了球囊-动脉相互作用，并考虑了血管特异性轴向原位预拉伸。分析研究动脉在球囊扩张和支架部署过程中的三维应力状态。此外，我们研究了由于模型简化而导致的三维应力状态的变化，其特点是忽略了以往工作中常用的轴向原位预拉伸，假设平面应变状态和各向同性材料响应。由于这些简化导致最大应力偏差高达600%，甚至应力特征也可能互换，因此相关模型通常是不合适的。提出的方法提供了一种工具，具有以下潜力：(1)在病变特异性的基础上改进手术方案和介入器械的设计，以及(2)确定血管成形术后的机械环境，这可能与再狭窄反应相关。(C) 2002生物医学工程学会。
A detailed understanding of the mechanical procedure of balloon angioplasty requires three-dimensional (3D) modeling and efficient numerical simulations. We have developed a 3D model for eight distinct arterial components associated with specific mechanical responses. The 3D geometrical model is based on in vitro magnetic resonance imaging of a human stenotic postmortem artery and is represented by nonuniform rational B-spline surfaces. Mechanical tests of the corresponding vascular tissues provide a fundamental basis for the formulation of large strain constitutive laws, which model the typical anisotropic, highly nonlinear, and inelastic mechanical characteristics under supraphysiological loadings. The 3D finite-element realization considers the balloon-artery interaction and accounts for vessel-specific axial in situ prestretches. 3D stress states of the investigated artery during balloon expansion and stent deployment were analyzed. Furthermore, we studied the changes of the 3D stress state due to model simplifications, which are characterized by neglecting axial in situ prestretch, assuming plane strain states, and isotropic material responses, as commonly utilized in previous works. Since these simplifications lead to maximum stress deviations of up to 600%-where even the stress character may interchange-the associated models are, in general, inappropriate. The proposed approach provides a tool that has the potential (i) to improve procedural protocols and the design of interventional instruments on a lesion-specific basis, and (ii) to determine postangioplasty mechanical environments, which may be correlated with restenosis responses. (C) 2002 Biomedical Engineering Society.