"We may determine that the fetus has a potentially fatal arrhythmia that must be treated immediately," says Strasburger. "While rare, this treatment might include medications that the mother takes, or direct shots of medication given by a pregnancy specialist, similar to an immunization injection."
The passive detector, mounted on a track above a table upon which the patient lies, is positioned over the pregnant woman's belly, where it picks up the faintest magnetic signals and sends the information back to a computer in an adjacent room. The safe, non-invasive test takes about an hour.
Unlike MRI, which produces a magnetic field, this magnetic recorder does not. It listens for naturally-occurring magnetic fields.
"Currents flowing through the heart and brain generate these magnetic signals," explains Wakai. "They're the same currents that generate electrical signals detected by EKGs and EEGs."
The EKG is the standard test for adults with heart rhythm problems, but it doesn't work on fetuses, adds Wakai.
"A slimy protective layer on the fetal skin, called the vernix, prevents electrical signals from being conducted to the surface of the expectant mother's body, where they could be measured," he says. "Magnetic signals, which don't require electrical conductivity, aren't affected by the vernix."
The only detector sensitive enough to measure these signals is a superconducting quantum interference device, or SQUID, which was invented by physicists and has been
|Contact: Toranj Marphetia|
Medical College of Wisconsin