PreTeL, Inc., Chattanooga, TN, USA.
Department of Obstetrics and Gynecology, University of Rochester, Rochester, NY, USA.
Reprod Sci. 2023 Nov;30(11):3190-3196. doi: 10.1007/s43032-023-01268-y. Epub 2023 May 22.
Multichannel uterine electromyography (uEMG) during pregnancy is traditionally performed with electrocardiography (ECG) sensors. Similar signals are often observed in two or more channels, suggesting the ECG sensors report activities originating from the same location on the uterus. To improve signal source localization, we designed a directional sensor or "Area Sensor". Here we compare Area Sensors with ECG sensors for source localization. Subjects were ≥ 38 wks experiencing regular contractions. 6 Area Sensors (n = 8) or 6 to 7 ECG sensors (n = 7) were used to record multichannel uEMG for 60 min. For each sensor type, the similarity of signals observed in pairs of channels during contractions was assessed by quantifying channel crosstalk. Since crosstalk depends on the separation between sensors, analyses were performed within distance groups: A 9-12 cm; B 13-16 cm; C 17-20 cm; D 21-24 cm; E ≥ 25 cm. For ECG sensors, crosstalk was 67.9 ± 14.4% in group A, decreasing to 27.8 ± 17.5% in group E. For Area Sensors, crosstalk was 24.6 ± 18.6% in Group A, decreasing to 12.5 ± 13.8% in group E. Area Sensors showed less crosstalk than ECG sensors in distance groups A, B, C and D, with all p < 0.002. Compared with ECG sensors, Area Sensors are more directional and report uterine activity from a smaller area of the uterine wall. Using 6 Area Sensors separated by at least 17 cm provides acceptably independent multichannel recording. This introduces the possibility of non-invasively evaluating uterine synchronization and the strength of individual uterine contractions in real time.
多通道子宫肌电图（uEMG）在妊娠期间传统上使用心电图（ECG）传感器进行测量。在两个或更多通道中经常观察到相似的信号，这表明 ECG 传感器报告的活动源自子宫的同一位置。为了改善信号源定位，我们设计了一种定向传感器或“区域传感器”。在此，我们将区域传感器与 ECG 传感器进行比较，以实现源定位。受试者≥38 周并经历有规律的宫缩。使用 6 个区域传感器（n=8）或 6 到 7 个 ECG 传感器（n=7）记录 60 分钟的多通道 uEMG。对于每种传感器类型，通过量化通道串扰来评估收缩期间对双通道信号的相似性。由于串扰取决于传感器之间的距离，因此在距离组内进行分析：A 为 9-12cm；B 为 13-16cm；C 为 17-20cm；D 为 21-24cm；E 为≥25cm。对于 ECG 传感器，在 A 组中串扰为 67.9±14.4%，在 E 组中降低至 27.8±17.5%。对于区域传感器，在 A 组中串扰为 24.6±18.6%，在 E 组中降低至 12.5±13.8%。区域传感器在距离组 A、B、C 和 D 中显示出比 ECG 传感器更少的串扰，所有 p 值均<0.002。与 ECG 传感器相比，区域传感器具有更强的方向性，可报告来自子宫壁较小区域的子宫活动。使用至少相隔 17cm 的 6 个区域传感器可以提供可接受的独立多通道记录。这为实时非侵入性评估子宫同步性和单个子宫收缩的强度提供了可能性。
