Avci R, Escalona-Vargas D, Siegel E R, Lowery C L, Eswaran H
Annu Int Conf IEEE Eng Med Biol Soc. 2018 Jul;2018:1-4. doi: 10.1109/EMBC.2018.8513053.
Recent studies have shown that occasional short term coupling between fetal and maternal cardiac systems occurs. Fetal magnetocardiography (fMCG) is a non-invasive technique that records the magnetic fields associated with the electrical activity of the fetal heart through sensors placed over the maternal abdomen. The fMCG allows accurate estimation of fetal heart rates (fHR) due to its high signal-to-noise ratio (SNR) and temporal resolution. In this study, we analyzed couplingbetween fHR and maternal heart rates (mHR) using Transfer Entropy (TE). TE determines coupling between two variables by quantifying the information transferred between them in both directions. In this work, we used 74 fMCG recordings to compute TE in both directions over 1-minute disjoint time windows (TW). We examined the effect of fetal movement (FM) as a factor of influence on the TE analysis. We identified 21 subjects with FM during the recording and separated them into two gestational age (GA) groups (GA1<32 and GA2≥32 weeks). Next, TE values were compared between TWs containing non- FM with TWs containing FM using Wilcoxon Signed-Rank test. In addition, we compared TE calculations for non-FM segments obtained from the 74 subjects using Rank-Sum test in the two GA groups. Our results showed that TE values from TWs containing FM are not significantly different than those computed for TWs of non-FM. In both directions, we found that TE values obtained from the 74 subjects did not show any significant difference between GA1 and GA2 which is consistent with previous studies. Our study suggests that FM does not affect the TE computations.
最近的研究表明，胎儿和母体心脏系统之间偶尔会出现短期耦合。胎儿磁心动图（fMCG）是一种非侵入性技术，通过放置在母体腹部的传感器记录与胎儿心脏电活动相关的磁场。由于其高信噪比（SNR）和时间分辨率，fMCG能够准确估计胎儿心率（fHR）。在本研究中，我们使用转移熵（TE）分析了fHR与母体心率（mHR）之间的耦合。TE通过量化两个变量之间双向传递的信息来确定它们之间的耦合。在这项工作中，我们使用74个fMCG记录在1分钟不重叠的时间窗口（TW）内双向计算TE。我们研究了胎儿运动（FM）作为影响TE分析的一个因素的作用。我们确定了21名在记录过程中有FM的受试者，并将他们分为两个孕周（GA）组（GA1<32周和GA2≥32周）。接下来，使用Wilcoxon符号秩检验比较包含非FM的TW与包含FM的TW之间的TE值。此外，我们在两个GA组中使用秩和检验比较了从74名受试者获得的非FM段的TE计算结果。我们的结果表明，包含FM的TW的TE值与非FM的TW计算出的TE值没有显著差异。在两个方向上，我们发现从74名受试者获得的TE值在GA1和GA2之间没有显示出任何显著差异，这与先前的研究一致。我们的研究表明，FM不会影响TE计算。
