Apr 8 2010
A magnetic detector, among the most powerful in the world, is facilitating the screening of pregnant patients at high-risk of suffering from very serious and rare fetal heart rhythm problems.
This ultrasonic magnetic detector is able to measure magnetic signals transmitted from the tiny heart beats of fetuses.
The research work on this detector is collaborated by the Medical College of Wisconsin, Milwaukee, the University of Wisconsin-Madison, and Hope Children's Hospital, Chicago. The obstetricians and the pediatric cardiologists in the U.S. are able to collect data and provide the best treatment options to their patients using this research program.
The fetuses’ hearts to be evaluated would beat very slowly or race or skip beats. Their cardiac performance is also likely to be affected by structural abnormalities. By finding out what is happening exactly, the doctors can treat patients accordingly. The results analyzed from the recordings, along with data received from existing technologies like ultrasound, help physicians to provide the right treatment options including waiting and observing with caution, prescription of medications, and deliver the fetus as early as possible.
The passive magnetic detector is positioned on a track over the table where the patient lies. The detector, placed over the belly of the pregnant woman, is able to pick up even the weakest magnetic signals and transmits the signal back to a PC placed in an adjoining room. It takes about an hour to complete the non-invasive and safe test.
The magnetic detector does not produce a magnetic field, unlike the MRI. The detector is able to listen to naturally occurring magnetic fields. It has been utilized to study and evaluate irregularities in heartbeats for more than 300 patients till now by the Wisconsin team.
UW School of Medicine and Public Health’s professor of medical physics, Dr. Ron Wakai, who created the lab, informed that the currents that flow through the brain and the heart generate magnetic signals and are the same currents responsible for the generation of electric signals identified by the EEGs and EKGs. The EKG, a standard technique for adults having heart rhythm problems, cannot be used on fetuses, according to Wakai.
Wakai informed that the fetal skin’s protective layer vernix obstructs the conduction of electrical signals on to the expectant mother’s body surface, where these signals could be measured. He added that magnetic signals are unaffected by the vernix, since they do not need electric conductivity.
A superconducting quantum interference device (SQUID) is the only detector with sufficient sensitivity to measure magnetic signals. The detector, used in medical, oil exploration, and submarine detection applications, was invented by physicists. However, very few hospitals have the SQUIDS that are almost exclusively utilized for adult brain mapping analysis. According to Wakai, the SQUIDD detector takes only an hour for continuous recordings. He adds that on the other hand the most commonly used technology to measure fetal heart rhythms, namely the ultrasound, is able to capture only a small portion of the activity.
At present the testing is confined to patients who come to Madison. Janette Strasburger, a pediatric cardiologist at Children's Hospital of Wisconsin, and a professor of pediatrics at The Medical College of Wisconsin are planning to offer technical and scientific support for a project that will be a road show and a mobile unit is under construction currently.
Source: http://www.wisc.edu