BIOMAGNETIC MEASUREMENTS UTILIZING A SUPERPARAMAGNETIC MARKER - A FEASIBILITY STUDY

A preliminary study is here reported on a new potential marker for bio magnetic measurements. The marker consists of superparamagnetic polyme r microspheres which were detected in the presence of external steady magnetic fields by means of an r.f.-SQUID magnetometer. The particles were prepared in samples differing in the concentration value and imme rsed in a homogeneous magnetic field of variable intensity. A simple m odel was taken into account for the distribution of the microspheres i n the samples, so that the theoretical values were compared to the mar ker field values measured by the biomagnetic sensor. The overall sensi tivity of the experimental apparatus and the minimum concentration val ue of the marker were then estimated.