Research on the developmental changes of central nervous system in the fetus using magnetocardiography and magnetoencephalography

心磁图和脑磁图研究胎儿中枢神经系统发育变化

• 批准号: 12671061
• 负责人: HORIGOME Hitoshi
• 金额: $ 2.11万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12671061/
• 关键词: Biomagnetism; magnetocardiography; magnetoencephalography; fetus; prenatal diagnosis; heart rate variability; SQUID; 胎児心磁図; 心拍数変動; 自律神経機能; 自律神経系; 生体磁気計測; 周波数解析

To assess the functional development of fetal central nervous system, we first analyzed heart rate variability in the fetus based on the data set of RR intervals obtained by fetal megnetocardiography (fMCG), fMCG was recorded in uncomplicated fetuses with the gestational age of 20-40 weeks, and power spectral analysis was applied to calculate the power of the low frequency band (LF), high frequency band (HF) and LF/HF ratio. Consequently, it was demonstrated that the power of LF (sympathetic activity) increases significantly with the gestational age although that of HF (parasympathetic activity) remained unchanged during the period. The LF/HF ratio also increases in proportion with the gestational age, indicating sympathetic dominance in later gestation. Thus, .fMCG is recognized as useful methodology to evaluate fetal autonomic nervous system or fetal well-being, as the detection rate of R waves and the time resolution are very high.Then, we attempted to measure auditory evoked magnet … More ic fields of the fetal - brain. The detection of fetal megnetoencephalogram (fMEG) has been considered very hard because the magnitude of fMEG signals is much weaker than that of fMlCG, almost at the level of units of 10^<-14> Tesla, and because signal averaging technique is difficult to apply due to non-cyclic nature of the signals. To improve the success, rate of recording fMEG, we refined the sensors of the SQUID system and realized spatial resolution of <10 fT/√<Hz>. fMEG was recorded over the site of fetal skull on maternal abdomen under stimulation with acoustic pulses (frequency, 0.5 or 1KHz ; magnitude, 70-100 dB ; width, 50 msec) with a stimulus frequency of 0.5 Hz for 8 min. The signals obtained were averaged triggered by the acoustic pulse. With this methodology, a peak of MEG signal was detected at 120 msec after the pulse in neonates immediately after birth, and two peaks were detected at 120 and 220 msec after the pulse in infants. However, no apparent fMEG peaks were determined for fetuses even in full term. We concluded that further improvement of sensitivity of the SQUID system, auditory stimulation and recording methods, and post processing of the'data would be required to assess the functional development or maturation of the fetal brain using fMEG. Less

为了评价胎儿中枢神经系统的功能发育，我们首先根据胎心巨波图(FMCG)获得的RR间期数据分析了胎儿心率变异性，记录了胎龄20~40周的无并发症胎儿的FMCG，并用功率谱分析计算了低频段(LF)、高频段(HF)和LF/HF比值的功率。结果表明，交感神经活动(LF)的功率随胎龄的增加而显著增加，而副交感神经活动(HF)的功率在此期间保持不变。低频/高频比值也随着胎龄的增加而增加，提示交感神经在妊娠后期占优势。因此，fMCG被认为是评估胎儿自主神经系统或胎儿健康的有用方法，因为R波的检测率和时间分辨率都很高。然后，我们尝试测量听觉诱发磁体…更多的胎儿脑区。胎儿巨脑电信号(FMEG)的检测一直被认为是非常困难的，因为fMEG信号的幅度比fMlCG弱得多，几乎在10个单位特斯拉的水平上，而且由于信号的非周期性，信号平均技术很难应用。为了提高记录fMEG的成功率，我们改进了SQUID系统的传感器，实现了&lt；10FT/√&lt；Hz&gt；的空间分辨率。刺激频率为0.5 Hz的声脉冲(频率为0.5 KHz或1 KHz，幅度为70~100分贝，宽度为50毫秒)，在母体腹部胎儿颅骨部位记录fMEG，持续8min。获得的信号由声脉冲触发进行平均。用这种方法，新生儿在出生后立即检测到脉冲后120毫秒处的脑磁图信号峰值，婴儿在脉冲后120毫秒和220毫秒处检测到两个峰值。然而，即使在足月，也没有明显的fMEG峰值被确定。我们的结论是，需要进一步提高SQUID系统的灵敏度，听觉刺激和记录方法，以及数据的后处理，才能使用fMEG评估胎儿大脑的功能发育或成熟。较少

项目成果

Stinstra J, Golbach E, Horigome H, et al.: "Multicentre study of fetal cardiac time intervals using magnetocardiography"British Journal of Obstetrics and Gynecology. 109・11. 1235-1243 (2002)

Stinstra J、Golbach E、Horigome H 等人：“使用心磁图进行胎儿心脏时间间​​隔的多中心研究”英国妇产科杂志 109・11（2002 年）。

Horigome H, et al.: "Magnetocardiographic determination of the developmental changes of PR, QRS and QT intervals in the foetus"Acta Paediatrica. 89. 64-67 (2000)

Horigome H 等人：“胎儿 PR、QRS 和 QT 间期发育变化的心磁图测定”Acta Paediatrica。

Hitoshi Horigome: "Magnetocardiographic determination of the developmental changes in PQ, QRS and QT intervals in the foetus."Acta Paediatrica. 89・1. 64-67 (2000)

Hitoshi Horigome：“胎儿 PQ、QRS 和 QT 间期发育变化的心磁图测定”Acta Paediatrica 89・1 (2000)。

Kandori A, et al.: "Prenatal diagnosis of QT prolongation by fetal magnetocardiogram. -use of QRS and T-wave current-arrow maps-"Physiological Measurement. 22. 377-387 (2001)

Kandori A 等人：“通过胎儿心磁图对 QT 间期延长进行产前诊断。-使用 QRS 和 T 波电流箭头图-”生理测量。

Horigome H, Shiona J, et al.: "Detection of cardiac hypertrophy in the fetus by approximation of the current dipole using magnetocardiography"Pediatric Research. 50・2. 242-245 (2001)

Horigome H、Shiona J 等人：“利用心磁图近似电流偶极子检测胎儿的心脏肥大”，儿科研究 50・2（2001 年）。