A Clinical Application of Superconductivity Technology

Abstract

The human body is enveloped by very weak magnetic fields which are generated by action currents and magnetic materials that have accumulated in the body. It is extremely difficult to measure these weak magnetic fields emanating from the human body. Fortunately, however, the rapid advance of superconductivity technologies has made extremely sensitive SQUID magnetometers available for this purpose.

Measurements of the magnetic fields produced by the currents in the human brain are recorded with magneto-encephalograms(MEG). We can diagnose many kinds of brain disorders such as epilepsy and analyze brain functions using MEG. The multi-channel SQUID systems have been developed to simultaneously measure the MEG at many sites on the surface of the human skull. A magnetocardiogram(MCG) is a record made outside the subject’s body of the action currents that accompany myocardial excitation. MCG signals are relatively large and can be measured by a high-Tc SQUID magnetometer. In addition to the above, measurements of the fields emanating from the lungs and other organs are also currently being studied.