Eichler Chad E, Cheng Leo K, Paskaranandavadivel Niranchan, Du Peng, Bradshaw Leonard A, Avci Recep
Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand; Department of Surgery, Vanderbilt University, Nashville, TN, USA.
Comput Biol Med. 2021 Feb;129:104169. doi: 10.1016/j.compbiomed.2020.104169. Epub 2020 Dec 8.
Magnetogastrography (MGG) is a non-invasive method of assessing gastric slow waves (SWs) by recording the resultant magnetic fields. MGG can capture both SW frequency and propagation, and identify SW dysrhythmias that are associated with motility disorders. However, the impact of the restricted spatial coverage and sensor density on SW propagation tracking performance is unknown. This study simulated MGG using multiple anatomically specific torso geometries and two realistic SW propagation patterns to determine the effect of different sensor configurations on tracking SW propagation. The surface current density mapping and center-of-gravity tracking methods were used to compare four magnetometer array configurations: a reference system currently used in GI research and three hypothetical higher density and coverage arrays. SW propagation patterns identified with two hypothetical arrays (with coverage over at least the anterior of the torso) correlated significantly higher with simulated realistic 3 cycle-per-minute SW activity than the reference array (p = 0.016, p = 0.005). Furthermore, results indicated that most of the magnetic fields that contribute to the performance of SW propagation tracking were located on the anterior of the torso as further increasing the coverage did not significantly increase performance. A 30% decrease in sensor spacing within the same spatial coverage of the reference array also significantly increased correlation values by approximately 0.50 when the signal-to-noise ratio was 5 dB. This study provides evidence that higher density and coverage sensor layouts will improve the utility of MGG. Further work is required to investigate optimum sensor configurations across larger anatomical variations and other SW propagation patterns.
磁胃图（MGG）是一种通过记录合成磁场来评估胃慢波（SWs）的非侵入性方法。MGG可以捕捉SW频率和传播情况，并识别与运动障碍相关的SW节律紊乱。然而，受限的空间覆盖范围和传感器密度对SW传播跟踪性能的影响尚不清楚。本研究使用多种解剖学特定的躯干几何模型和两种现实的SW传播模式模拟MGG，以确定不同传感器配置对跟踪SW传播的影响。使用表面电流密度映射和重心跟踪方法比较四种磁力计阵列配置：一种目前在胃肠研究中使用的参考系统和三种假设的更高密度和覆盖范围的阵列。与参考阵列相比，两种假设阵列（至少覆盖躯干前部）识别出的SW传播模式与模拟的现实每分钟3次周期的SW活动的相关性显著更高（p = 0.016，p = 0.005）。此外，结果表明，对SW传播跟踪性能有贡献的大部分磁场位于躯干前部，因为进一步增加覆盖范围并不会显著提高性能。当信噪比为5 dB时，在参考阵列相同空间覆盖范围内将传感器间距减小30%也显著提高了相关性值，提高幅度约为0.50。本研究提供了证据表明更高密度和覆盖范围的传感器布局将提高MGG的效用。需要进一步开展工作，以研究在更大的解剖变异和其他SW传播模式下的最佳传感器配置。
