Madani Ali, Bakhaty Ahmed, Kim Jiwon, Mubarak Yara, Mofrad Mohammad R K
Molecular Cell Biomechanics Laboratory,Department of Bioengineering,University of California,Berkeley, CA 94720;Department of Mechanical Engineering,University of California,Berkeley, CA 94720.
Molecular Cell Biomechanics Laboratory,Department of Bioengineering,University of California,Berkeley, CA 94720;Department of Mechanical Engineering,University of California,Berkeley, CA 94720;Department of Civil Engineering,University of California,Berkeley, CA 94720.
J Biomech Eng. 2019 Aug 1;141(8). doi: 10.1115/1.4043290.
Finite element and machine learning modeling are two predictive paradigms that have rarely been bridged. In this study, we develop a parametric model to generate arterial geometries and accumulate a database of 12,172 2D finite element simulations modeling the hyperelastic behavior and resulting stress distribution. The arterial wall composition mimics vessels in atherosclerosis-a complex cardiovascular disease and one of the leading causes of death globally. We formulate the training data to predict the maximum von Mises stress, which could indicate risk of plaque rupture. Trained deep learning models are able to accurately predict the max von Mises stress within 9.86% error on a held-out test set. The deep neural networks outperform alternative prediction models and performance scales with amount of training data. Lastly, we examine the importance of contributing features on stress value and location prediction to gain intuitions on the underlying process. Moreover, deep neural networks can capture the functional mapping described by the finite element method, which has far-reaching implications for real-time and multiscale prediction tasks in biomechanics.
有限元建模和机器学习建模是两种很少被联系起来的预测范式。在本研究中,我们开发了一个参数模型来生成动脉几何形状,并积累了一个包含12172个二维有限元模拟的数据库,这些模拟对超弹性行为和由此产生的应力分布进行建模。动脉壁成分模拟动脉粥样硬化(一种复杂的心血管疾病,也是全球主要死因之一)中的血管。我们制定训练数据以预测最大冯·米塞斯应力,该应力可指示斑块破裂风险。经过训练的深度学习模型能够在一个留出的测试集上以9.86%的误差准确预测最大冯·米塞斯应力。深度神经网络优于其他预测模型,并且性能随训练数据量的增加而提升。最后,我们研究了贡献特征对应力值和位置预测的重要性,以深入了解潜在过程。此外,深度神经网络可以捕捉有限元方法所描述的功能映射,这对生物力学中的实时和多尺度预测任务具有深远意义。