Doctors usually use electrical fields produced within the body to gain insights on the functioning of the heart, nerves, muscles, and brains as these fields produced within the body are a powerful diagnostic tool. But then this methodology has its own drawbacks. For instance, a mother’s signals can interfere with fetal heartbeats, overwhelming them. Furthermore, making it difficult to diagnose fetal heart conditions.
An alternate way to analyze the body’s electrical activity is by measuring the magnetic field it produces. As magnetic field degenerate rapidly over short distances, making it comparatively easier to segregate mother’s signal from the fetal signal.
The magnetic signals have always been hard and weak to interpret as the magnetometer with the necessary sensitivity relies on the superconducting technology that requires to be cooled to the temperature of liquid helium. Thus, the required insulation of these devices bars the device from getting close to the organ.
A room-temperature magnetometer that is sensitive enough to measure the magnetic signals of interest and can be placed within millimeters of the organ is perfect for the job.
The device devised by Kasper Jensen at the University of Copenhagen and colleagues has made this work easier. The device has the capability to transform the dimensions of magnetic fields that can aid in clinicians’ diagnosis of fetal heart conditions which are otherwise undetectable. The researchers have successfully measured different diagnostic fetal heart signals in the past using a room-temperature magnetometer.
Known as optically pumped magnetometer, the said device comprises of a small flask of cesium atom instead of a small flask of atomic gas. With the spin of each cesium atom, it detects the ambient magnetic fields, making them a useful measuring tool.
The recent years have seen various groups using optically pumped magnetometers to analyze biomagnetic fields. However, prevention of picking up the desired signals due to narrow bandwidth has led to the failure of this analysis.
Kasper and team experimented with the paces of the device by measuring the magnetic field of the isolated guinea pig hearts that were isolated in the lab for experimentation. They offer a good test as they are about the size of the human fetal heart. The team clearly detected the heartbeat along with varied diagnostic traits.
In a typical heart, the heartbeat is caused by the passage of electrical waves across the surface of the heart resulting in the signature muscle contraction. Several waves in unison cause this synchronized contraction of the heart.
These waves are labeled as P, Q, R, S, and T. The timing factor between them plays a crucial role in an indication of heart function. The important one being is the Q-T interval. Prolonged intervals between Q-T indicate a serious problem. Conversely, electrocardiograms do not prove to be effective in detecting this defect in fetal hearts.
Jensen and co. claimed that the new approach can identify this problem. After using drugs to bring a protracted Q-T interval in the guinea pig hearts, the optically pumped magnetometer evidently detected the problem-solving signs.
This positions an exciting future. The next step will however involve testing the methodology in humans and then ultimately in pregnant women. It also has the capability to measure erstwhile magnetic fields produced by the nervous system and brain.