Assuming three dipoles inside a spherical conducting medium, the radial component of the magnetic field (B{sub}r) generated due to these dipoles is computed using the Biot-Savart law at 141 measurement locations. The temporal variation of the dipole strengths (Q's) is separately modeled to produce 50 time slices. To simulate the actual measurement situation, a Gaussian noise of 5% of the maximum is added to the computed data. Using these sets of computed noisy data B, and with an apriori knowledge of the number of dipoles, we have used the pseudo-inverse technique to factor out the linear moment variables and present only the nonlinear position variables to the minimization algorithm. It has been possible to identify the location of the three dipoles to an accuracy of 1-2 mm within the cortex.
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