POSITION SENSING OF MAGNETITE GEL USING MI SENSOR FOR BRAIN-TUMOR DETECTION

A brain tumor position sensing method using an MI (magneto impedance) micro magnetic sensor in combination with fine magnetic particles (FMP for short) is proposed. Sensing of magnetic field generated from FMP accumulated in the brain tumor tissue would be an effective way to acc urately detect the tumor position in the surgical operation. The spati al distributions of stray fields in gel samples, in which FMP were dis persed, were measured using an MI gradient-field sensor. The position of samples having FMP concentration of more than 0.1g/l was clearly de tected due to the high sensitivity (2 x 10(-5) Oe for a dc field) of t he sensor. The spatial distributions were analyzed by a model of align ed dipole moments. The calculation results using the model were in goo d agreement with experimental results. Position sensing of the tumor t issue of a rat was also carried out. It mas concluded that the propose d method would be useful for not only position sensing of tile brain t umor but also 3D imaging of the tumor shape.