Apparatus for Continuous Monitoring of the Fetal Heart Rate *

APPARATUS FOR CONTINUOUS MONITORING OF THE FETAL HEART RATE.* By Edward H. Hon, Department of Obstetrics and Gynecology, Yale University School of Medicine. During the past four years continuous monitoring of fetal heart rate during labor and delivery has permitted the accumulation of accurate, permanent records which may be of value for the assessment of fetal heart rate as an index of fetal environment. The QRS complex of the fetal ECG has been used as a trigger source for a cardiotachometer and oscillograph system.`3 The major difficulty has been the elimination of the maternal ECG from the combined maternal and fetal ECG tracing. Various separation methods have been used with some success; the most promising is the attachment of a small electrode to the fetal scalp or buttocks. This method has been used for over a year and