HEART MONITORING WITH HIGH-T-C DC SQUID GRADIOMETERS IN AN UNSHIELDEDENVIRONMENT

We have developed one-channel high-T-c d.c. SQUID heart monitoring sys tem for non-invasive measurements in an unshielded environment. This s ystem gives fast and reliable information about the heart condition of a patient, for example in an emergency case. Planar galvanically coup led thin film gradiometers and magnetometers with step-edge and bicrys tal junctions have been prepared. These sensors were used to carry out magneto-cardiogram measurements in a magnetically shielded room with open doors as well as in an unshielded environment. The results of the se measurements are presented and different filtering and averaging me thods of the data discussed.