Evaluation of the performance of a QRS detector for extracting the heart interbeat RR time series from fetal magnetocardiography

Fetal magnetocardiography is a useful technique for non-invasive diagnostics of the electrophysiological activity of the fetal heart. The purpose of this study was to acquire fetal magnetocardiograms (FMCG) in a magnetically shielded environment as well as in a high-frequency noise environment, implement a QRS detection algorithm, and evaluate its performance. The FMCG were recorded over a period of 5 minutes at several sensor locations above the pregnant abdomen by second-order SQUID gradiometers. Quantitative analysis of FMCG with normal pregnancies and gestational ages 26-35 weeks showed improved QRS detection performance with signal pre-processing and parameter tuning.