[FieldTrip] Fitting a Magnetic Dipole

Little, Graham Graham.Little at nrc-cnrc.gc.ca
Wed Nov 16 14:51:37 CET 2011

Hi all,

I am currently trying to Fit a dipole to HPI coil locations to perform head position correction in fieldtrip.  Currently I am using the ft_dipolefitting function to generate the coil locations from a section of MEG data. Before running ft_dipolefitting I do an fft on the data to measure the complex valued MEG topography for each coil frequency.  The topographies look great for each coil, you can definitely see where each dipole should be fitted, however when using ft_dipolefitting the locations I get back are incorrect.

I believe this is due to the fact that ft_dipolefitting assumes an Equivalent Current Dipole, but the coils generate a Magnetic Dipole.  Anyway to tell ft_dipolefitting to fit a Magnetic Dipole rather than the ECD solution.

Any information would be helpful.

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