**3.7 Bispectral contour matching of the maternal QRS-complex and fetal heartbeat**

The bispectral contour template matching technique works with only 10 templates of maternal transabdominal QRS-complexes and 20 templates of fetal heartbeats with maternal contribution. The classification of the four segments involves a pattern-by-pattern updating rather than batch updating for the weight adjustments. This is more suitable to speed up the performance. Pattern-by-pattern updating tends to be orders of magnitude faster than batch updating. However, it should be noted that pattern-by-pattern updating is harder to parallelise (Zgallai, 2012).
