• 作者： 陳慶真; 郭士民; 洪正修; 高才
• 作者服務機構： 國立陽明醫學院醫事工程研究所; 榮民總醫院婦產科
• 中文摘要： 本研究之目的是在設計一個硬、軟體系統，可以在母親懷孕早期，以非侵人性的方式，經由母親腹部上擷取心電圖的訊號並加以處理，使得胎兒的心電圖訊號能與母親的心電圖訊號及雜訊分開，以取得胎兒之心電圖訊號，藉由此一系統除了可以用來計算胎兒的心率(Fetal Heart Rate)外，並可以用來測知孕婦在妊娠期間，胎兒是否有心律不整(arrhythmia)的現象。 在傳統上，杜卜勒超音波儀(Doppler ultrasound)和心音儀(phonocardiography)一直被用來測知孕婦懷孕期間胎兄心臟的發育情形，但是仍無法完全去除因胎兒活動所造成的雜訊和診斷偏差。此時，若將本研究所設計之胎兒心電圖訊號處理系統與杜卜勒超音波儀合用，同步紀錄與分析胎兒的心電圖訊號和經由杜卜勒超音波儀所取得的超音波訊號(Doppler cardiogram)，更可以用來計算胎兒心臟週期的PEP時間(pre-ejection period）. PEP時間是心室去極化(De-polarization-QRS波）到主動脈瓣（Aortic valve)打開的這一段時間，亦即是心室等容收縮(isovolumentric ventricularcontraction) 所經歷的時間。胎兒PEP時間的長短，除了可以反應孕婦懷孕週數的長短外，也與胎兒的心肌收縮力(Myocardial contractility)和心臟血管系統的血液動力狀態有關聯（Cerutti et al.,1986）。因此，計算胎兒心臟週期的PEP時間，除了可以提供醫師用來測知孕婦的懷孕週數外，也可藉此PEP時間的長短來瞭解胎兒心臟發育的情形。
• 英文摘要： A noninvasive method is described to measure the human fetal pre-ejection period (PEP) with thecombined use of the abdominal electrocardiogram (ECG) and Doppler ultrasound during pregnancy. ThePEP, which is related to the contractility of the fetal heart, is defined as the interval from the beginning ofthe QRS to the opening of the aortic valve (Q-Ao). An algorithm including median filtering and templatecrosscorrelation was designed to extract fetal QRS complexes from the abdominal ECG signal. Signalcomponents of the Doppler ultrasound output corresponding to the activity of the aortic valve was enhanc-ed by means of a 600-800 Hz Butterworth bandpass filter. Fifty-one patients were monitored between 20-40 weeks of gestation. The PEP was obtained in 80 per cent of the subjects (41 of 51）. The ventricularejection time (VET) was measured directly from the velocity spectral profile of the M-mode ultrasonicimage. Linear regression analysis of PEP, VET, and PEP/VET against gestational age (GA) and fetal heartrate (FHR) were performed. The PEP and the PEP/VET ratio were found to correlate significantly to thegestational age and the fetal heart rate. The 90 per cent confidential interval was drawn to predict thefetal age of gestation.
• 中文關鍵字： fetal electrocardiogram; pre-ejection period; doppler ultrasound; gestational age
• 英文關鍵字： --