The present invention provides a magnetic monitoring system for imaging, monitoring, scanning or mapping for brain or heart activity of subjects including children and adults, the system comprising of a magnetoencephalographic or magnetocardiographic system incorporating SQUID sensors for measuring brain activity or heart activity, the system including a plurality of Dewar helmets of variable sizes and shapes; and a plurality of monitoring interfaces; wherein the sensor system helmet is moveable by horizontal Dewar rotation. The sensor system includes configurations where the size and shape of helmets in the system may be different to accommodate different sized subjects for monitoring simultaneously.