论文标题

部分可观测时空混沌系统的无模型预测

Classification of stroke using Neural Networks in Electrical Impedance Tomography

论文作者

Agnelli, Juan Pablo, Çöl, Aynur, Lassas, Matti, Murthy, Rashmi, Santacesaria, Matteo, Siltanen, Samuli

论文摘要

电阻抗断层扫描(EIT)是一种新兴的非侵入性医学成像方式。它基于将电流进食到患者,测量皮肤的产生电压并恢复内部电导率分布。 EIT图像重建的数学任务是一个非线性和不良反向问题。因此,任何EIT图像重建方法都需要正规化,通常会导致图像模糊。一种有希望的应用是中风或中风分类为缺血或出血。缺血性中风涉及血块,防止血液流到大脑的一部分,从而导致低导率区域。出血性中风意味着在大脑中出血,导致高导体区域。在这两种情况下,症状都是相同的,因此需要具有成本效益和便携式分类装置。典型的EIT由于模糊而不是中风的最佳选择。本文探讨了机器学习改善分类结果的可能性。比较了两个范式:(a)从EIT数据中学习,即Dirichlet到Neumann(DN)地图,(B)从数据中提取强大的功能并从数据中学习。选择的特征是虚拟杂交边缘检测(VHED)函数[greenleaf {\ it等},分析\&PDE 11,2018],它们具有几何解释,并且来自EIT数据的计算不涉及计算电导率的完整图像。我们报告了用EIT数据和VHED函数训练的网络的准确性,灵敏度和特异性的度量。基于模拟噪声EIT数据的计算证据表明,正则化的灰色盒范式(B)导致的分类结果明显好于Black-box范式(a)。

Electrical Impedance Tomography (EIT) is an emerging non-invasive medical imaging modality. It is based on feeding electrical currents into the patient, measuring the resulting voltages at the skin, and recovering the internal conductivity distribution. The mathematical task of EIT image reconstruction is a nonlinear and ill-posed inverse problem. Therefore any EIT image reconstruction method needs to be regularized, typically resulting in blurred images. One promising application is stroke-EIT, or classification of stroke into either ischemic or hemorrhagic. Ischemic stroke involves a blood clot, preventing blood flow to a part of the brain causing a low-conductivity region. Hemorrhagic stroke means bleeding in the brain causing a high-conductivity region. In both cases the symptoms are identical, so a cost-effective and portable classification device is needed. Typical EIT are not optimal for stroke-EIT because of blurriness. This paper explores the possibilities of machine learning in improving the classification results. Two paradigms are compared: (a) learning from the EIT data, that is Dirichlet-to-Neumann (DN) maps and (b) extracting robust features from data and learning from them. The features of choice are Virtual Hybrid Edge Detection (VHED) functions [Greenleaf {\it et al.}, Analysis \& PDE 11, 2018] that have a geometric interpretation and whose computation from EIT data does not involve calculating a full image of the conductivity. We report the measures of accuracy, sensitivity and specificity of the networks trained with EIT data and VHED functions separately. Computational evidence based on simulated noisy EIT data suggests that the regularized grey-box paradigm (b) leads to significantly better classification results than the black-box paradigm (a).

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源