Wabina R S, Silpasuwanchai C
Center for Health and Wellness Technology, Asian Institute of Technology (AIT), Khlong Luang, Pathum Thani, Thailand.
Biomed Phys Eng Express. 2023 Feb 22;9(2). doi: 10.1088/2057-1976/aca20b.
EEG source localization remains a challenging problem given the uncertain conductivity values of the volume conductor models (VCMs). As uncertain conductivities vary across people, they may considerably impact the forward and inverse solutions of the EEG, leading to an increase in localization mistakes and misdiagnoses of brain disorders. Calibration of conductivity values using uncertainty quantification (UQ) techniques is a promising approach to reduce localization errors. The widely-known UQ methods involve Bayesian approaches, which utilize prior conductivity values to derive their posterior inference and estimate their optimal calibration. However, these approaches have two significant drawbacks: solving for posterior inference is intractable, and choosing inappropriate priors may lead to increased localization mistakes. This study used the Neural Stochastic Differential equations Network (SDE-Net), a combination of dynamical systems and deep learning techniques that utilizes the Wiener process to minimize conductivity uncertainties in the VCM and improve the inverse problem. Results revealed that SDE-Net generated a lower localization error rate in the inverse problem compared to Bayesian techniques. Future studies may employ new stochastic dynamical systems-based techniques as a UQ technique to address further uncertainties in the EEG Source Localization problem. Our code can be found here:https://github.com/rrwabina/SDENet-UQ-ESL.
鉴于容积导体模型(VCM)的电导率值不确定,脑电图源定位仍然是一个具有挑战性的问题。由于不确定的电导率因人而异,它们可能会对脑电图的正解和逆解产生重大影响,导致脑疾病定位错误和误诊的增加。使用不确定性量化(UQ)技术校准电导率值是减少定位误差的一种有前景的方法。广为人知的UQ方法包括贝叶斯方法,该方法利用先前的电导率值来推导其后验推断并估计其最佳校准。然而,这些方法有两个显著缺点:求解后验推断很棘手,选择不合适的先验可能会导致定位错误增加。本研究使用了神经随机微分方程网络(SDE-Net),这是一种动态系统和深度学习技术的组合,利用维纳过程来最小化VCM中的电导率不确定性并改善逆问题。结果表明,与贝叶斯技术相比,SDE-Net在逆问题中产生的定位错误率更低。未来的研究可能会采用基于新的随机动态系统的技术作为一种UQ技术,以解决脑电图源定位问题中的进一步不确定性。我们的代码可在此处找到:https://github.com/rrwabina/SDENet-UQ-ESL。