Early detection of a fetal heartbeat can be important in many cases where close monitoring of the development of the child is necessary. The difficulty is that the tiny heart’s signal is dwarfed by the mother’s own heartbeat, making it difficult to pick out the quieter fetal heart. Current fetal heart rate monitoring technologies rely on an acoustic signal to pick out the baby’s heart. Now an international group of researchers (MIT, Institut National Polytechnique de Grenoble, Sharif University, Tufts Medical Center, and E-TROLZ Inc.) have developed software that can unscramble the ECG to pick out the fetal heartbeat much earlier than clinics currently can.
From MIT news office:
The new system separates the maternal ECG signal from the fetus’s and background noise thanks to a complex algorithm derived from the fields of signal processing and source separation. Together, these fields work to break any signal into its source components.
To use the system, which the team believes could be deployed during the second trimester of pregnancy (around 20 weeks) and perhaps earlier, a woman would wear a wide belt around her abdomen fitted with several ECG electrodes. (The prototype has 32, but that number will be lower in the final device.) The data collected from those electrodes are then fed to a monitor and analyzed with the new algorithm, which in turn separates the different signals.
Clifford [Gari Clifford, PhD, research scientist at the Harvard-MIT Division of Health Sciences and Technology] notes that “one of the nice things about monitoring the fetal ECG through the mother’s abdomen is you’re getting a multidimensional view of the fetal heart” because its electrical activity is recorded from many different angles. The single probe now used to monitor the heartbeat during labor gives data from only one direction.
“So with our system it’s like going from a one-dimensional slice of an image to a hologram,” Clifford said.
That better view could help catch problems that might have gone unnoticed before. “If you’re looking in just one direction and an abnormality is occurring perpendicular to that direction, you won’t see it,” Clifford said.
The large amounts of 3-D data captured with the new system could also open up a new field of research: fetal electrocardiography. “The world of fetal ECG analysis is almost completely unexplored,” Clifford said, because the current monitoring system can only be used during labor and “essentially gives only a monocular view.”
MIT news release: New system allows earlier monitoring of fetal heartbeat
Image : Acoustic heartbeat monitoring. Telstar Logistics
