2000 Volume 5 Issue 2 Pages 867-874
The principle of the scalp skull and brain dipole tracing (SSB/DT) method and its application were described. The SSB/DT method enabled to estimate the location of current dipoles from EEG (10-20 international system). The main principle of the arithmetic algorithm consisted in the calculation of the local minimum of the evaluated function; that is, the difference of the recorded and the estimated potentials on the scalp. Before calculation, the three-layered head model of individual subjects was constructed based on X ray-CT photographs taken 5 mm interval of the horizontal plane. The conductance of the scalp, skull and brain, which is very important for precise calculation of the current dipole, was estimated by passing a small amount of rectangular current (0. 1 mA x 5 msec) at the scalp. Several physiological studies conducted in our and other laboratories demonstrated the usefullness of the SSB/DT method.
