OT: Bio-Magnetic Sensors

Continuing from a different thread, where this has come up. I knew that they were using super conductivity for magnetic scanning of brain waves. They say it is better than using electrodes. But liquid Helium, not even liquid Nitrogen temperature yet? And then scanning the heart? And an in utero fetal heart? And then using ferrites, and TDK claiming to have invented ferrite? You need ferrite anytime you want an RF transformer, like for a herteodyne radio receiver. 1920's? Do they do a mapping and an inverse 2-D spacial Fourier transform to make an image? Want to know more about this. [view link] [view link] good: [view link] Basic introduction to bioelectromagnetics (2009 CRC Press) Basic introduction to bioelectromagnetics / Carl H. Durney, Douglas A. Christensen (2000 CRC Press) SJG