IEEE Trans Biomed Eng. 2022 Nov;69(11):3551-3558. doi: 10.1109/TBME.2022.3174847. Epub 2022 Oct 19.
The motility patterns in the gastrointestinal tract are regulated, in part, by bioelectrical events known as slow waves (SWs). Understanding temporal and spatial features of gastric SWs can help reveal the underlying causes of functional motility disorders.
This study investigated the ability of source localization techniques to characterize the spatial signatures of SW activity using simulated and experimental magnetogastrography data.
Two SW propagation patterns (antegrade and retrograde) with two rhythms (normogastric and bradygastric) were used to simulate magnetic fields using 4 anatomically realistic stomach and torso geometries. Source localization was performed utilizing the equivalent current dipole (ECD) and the equivalent magnetic dipole (EMD) models.
In the normogastric simulations when compared with the SW activity, the EMD model was capable of identifying the SW propagation in the lateral, antero-posterior, and supero-inferior axes with the median correlation coefficients of 0.66, 0.53, and 0.83, respectively, whereas the ECD model produced lower correlation scores (median: 0.52, 0.44, and 0.44). Moreover, the EMD model resulted in distinct and opposite spatial signatures for the antegrade and retrograde propagation. Similarly, when experimental data was used, the EMD model revealed antegrade-like signatures where the propagation was mostly towards the third quadrant in the supero-inferior (preprandial: 49%, postprandial: 35%) and antero-posterior (preprandial: 49%, postprandial: 50%) axes.
The EMD model was able to identify and classify the spatial signatures of SW activities, which can help to inform the interpretation of non-invasive recordings of gastric SWs as a biomarker of functional motility disorders.
胃肠道的运动模式部分受称为慢波 (SW) 的生物电事件调节。了解胃 SW 的时空特征有助于揭示功能性运动障碍的潜在原因。
本研究使用模拟和实验胃磁图数据，研究源定位技术表征 SW 活动空间特征的能力。
使用 4 个解剖学上逼真的胃和躯干几何形状，使用两种 SW 传播模式（顺行和逆行）和两种节律（正常胃节律和慢胃节律）来模拟磁场。使用等效电流偶极子 (ECD) 和等效磁偶极子 (EMD) 模型进行源定位。
在正常胃节律模拟中，与 SW 活动相比，EMD 模型能够在侧向、前-后和上-下轴上识别 SW 传播，中位数相关系数分别为 0.66、0.53 和 0.83，而 ECD 模型产生的相关分数较低（中位数：0.52、0.44 和 0.44）。此外，EMD 模型产生了顺行和逆行传播的独特且相反的空间特征。同样，当使用实验数据时，EMD 模型揭示了前向样特征，其中传播主要朝向下三分之一在supero-inferior（餐前：49%，餐后：35%）和前-后（餐前：49%，餐后：50%）轴。
EMD 模型能够识别和分类 SW 活动的空间特征，这有助于解释胃 SW 的非侵入性记录作为功能性运动障碍的生物标志物。
