Department of Pediatrics, Máxima Medical Centre, Veldhoven, the Netherlands.
Department of Pediatrics, Maastricht University Medical Centre, Maastricht, the Netherlands.
PLoS One. 2018 Apr 16;13(4):e0195978. doi: 10.1371/journal.pone.0195978. eCollection 2018.
The inconclusive clinical results for ST-waveform analysis (STAN) in detecting fetal hypoxemia may be caused by the signal processing of the STAN-device itself. We assessed the performance of a clinical STAN device in signal processing and in detecting hypoxemia in a fetal sheep model exposed to prolonged umbilical cord occlusion (UCO).
Eight fetal lambs were exposed to 25 minutes of UCO. ECG recordings were analyzed during a baseline period and during UCO. STAN-event rates and timing of episodic T/QRS rise, baseline T/QRS rise and the occurrence of biphasic ST-waveforms, as well as signal loss, were assessed.
During baseline conditions of normoxemia, a median of 40 (IQR, 25-70) STAN-events per minute were detected, compared to 10 (IQR, 2-22) during UCO. During UCO STAN-events were detected in five subjects within 10 minutes and in six subjects after 18 minutes, respectively. Two subjects did not generate any STAN-event during UCO. Biphasic ST event rate was reduced during UCO (median 0, IQR 0-5), compared to baseline (median 32, IQR, 6-55). ST-waveforms could not be assessed in 62% of the recording time during UCO, despite a good quality of the ECG signal.
The STAN device showed limitations in detecting hypoxemia in fetal sheep after prolonged UCO. The STAN device produced high false positive event rates during baseline and did not detect T/QRS changes adequately after prolonged fetal hypoxemia. During 14% of baseline and 62% of the UCO period, the STAN-device could not process the ECG signal, despite its good quality. Resolving these issues may improve the clinical performance of the STAN device.
ST 波形态分析（STAN）在检测胎儿缺氧方面的临床结果不确定，可能是由于 STAN 设备本身的信号处理所致。我们评估了一种临床 STAN 设备在信号处理方面的性能，并在胎儿羊模型中检测到暴露于长时间脐带结扎（UCO）下的缺氧情况。
将 8 只胎儿羊暴露于 25 分钟的 UCO 中。在基线期和 UCO 期间分析心电图记录。评估 STAN 事件率和阵发性 T/QRS 上升的时间、基线 T/QRS 上升和双相 ST 波的发生以及信号丢失。
在正常氧合的基线条件下，每分钟检测到中位数为 40（IQR，25-70）的 STAN 事件，而在 UCO 期间检测到中位数为 10（IQR，2-22）的 STAN 事件。在 UCO 期间，5 名受试者在 10 分钟内检测到 STAN 事件，6 名受试者在 18 分钟后检测到 STAN 事件。两名受试者在 UCO 期间未产生任何 STAN 事件。与基线相比（中位数 32，IQR，6-55），UCO 期间双相 ST 事件率降低（中位数 0，IQR 0-5）。尽管心电图信号质量良好，但在 UCO 期间的 62%的记录时间内无法评估 ST 波。
在长时间 UCO 后，STAN 设备在检测胎儿羊缺氧方面存在局限性。在基线期间，STAN 设备产生了高的假阳性事件率，并且在长时间胎儿缺氧后不能充分检测到 T/QRS 变化。在 14%的基线和 62%的 UCO 期间，尽管心电图信号质量良好，STAN 设备仍无法处理 ECG 信号。解决这些问题可能会提高 STAN 设备的临床性能。
