Neuromagnetic SQUID measurements in a helmet-type superconducting magnetic shield of BSCCO

Neuromagnetic superconducting quantum interference device (SQUID) measurements were performed on a human brain protected by a helmet-shaped superconducting magnetic shield made from Bi-Sr-Ca-Cu-Ox alloy. The cerebral magnetic fields were generated by electrically stimulating the tibial nerves of the right ancle of a human subject. The measured data show that the presence of the helmet-shaped magnetic shield reduced the low-frequency-noise components of the fields and enhanced the accuracy of the SQUID measurements.