目的:青少年特发性脊柱侧凸是一种可能需要矫正手术的慢性疾病。有限元方法(FEM)是在基于患者的模型上计划手术结果的流行选择。然而,它需要相当多的计算能力和时间,这可能会阻碍它的使用。机器学习(ML)模型可以是FEM的有用代理,提供准确的实时响应。这项工作实现了ML算法来估计术后脊柱形状。
方法:使用6400个模拟的特征对算法进行训练,这些模拟是使用64名患者脊柱几何形状的FEM生成的。使用自动编码器和主成分分析来选择特征。通过计算均方根误差以及每个椎骨的参考位置和预测位置之间的角度来评估结果的准确性。还报告了处理时间。
结果:用于降维的主成分分析的组合,其次是线性回归模型,实时生成准确的结果,在所有主要3D轴上,平均位置误差为3.75mm,取向角误差低于2.74度,在3ms内。预测时间比单独基于FEM的模拟快得多,这需要几秒钟到几分钟。
结论:通过使用ML算法作为FEM的替代,可以实时预测AIS患者的术后脊柱形状。临床医生可以比较AIS患者的初始脊柱形状对各种目标形状的反应,可以交互修改。这些好处可以鼓励临床医生使用软件工具进行脊柱侧凸的手术计划。
OBJECTIVE: Adolescent idiopathic scoliosis is a chronic disease that may require correction surgery. The finite element method (FEM) is a popular option to plan the outcome of surgery on a patient-based model. However, it requires considerable computing power and time, which may discourage its use. Machine learning (ML) models can be a helpful surrogate to the FEM, providing accurate real-time responses. This work implements ML algorithms to estimate post-operative spinal shapes.
METHODS: The algorithms are trained using features from 6400 simulations generated using the FEM from spine geometries of 64 patients. The features are selected using an autoencoder and principal component analysis. The accuracy of the results is evaluated by calculating the root-mean-squared error and the angle between the reference and predicted position of each vertebra. The processing times are also reported.
RESULTS: A combination of principal component analysis for dimensionality reduction, followed by the linear regression model, generated accurate results in real-time, with an average position error of 3.75 mm and orientation angle error below 2.74 degrees in all main 3D axes, within 3 ms. The prediction time is considerably faster than simulations based on the FEM alone, which require seconds to minutes.
CONCLUSIONS: It is possible to predict post-operative spinal shapes of patients with AIS in real-time by using ML algorithms as a surrogate to the FEM. Clinicians can compare the response of the initial spine shape of a patient with AIS to various target shapes, which can be modified interactively. These benefits can encourage clinicians to use software tools for surgical planning of scoliosis.