sensor geometries

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1

Hi all,

A collaborator I am working with is interested in using information
about the geometry of the MEG sensors for a custom visualization. As I
understand it, a sensor geometry is a numerical description of the
spatial relationships among the MEG sensors. Could anyone tell me where
I can access this information?

Thanks,

Matt

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2

Matt,

What information do you need? Just the location? If so, the information
is in the measurement information. Have a look at this example:

http://martinos.org/mne/auto_examples/connectivity/plot_sensor_connectivity.html

The orientation of the sensors is also stored, but I'm not sure how to
get that information. Maybe someone else can shed some light on this.

Best,

Martin

3

Hi Matt,

Here you go, sample matlab code for this is below

Sheraz

%------------------------------------------------------------------
in_fif_File='Any_fif_File.fif';
[fiffsetup] = fiff_setup_read_raw(in_fif_File);
chs=fiffsetup.info.chs(1:306);

for k=1:306

        chpos=chs(k).loc(1:3);
        chxdir=chs(k).loc(4:6);
        chydir=chs(k).loc(7:9);
        chzdir=chs(k).loc(10:12);

        sensors(k).pos=[chpos; 1];
        sensors(k).xdir=chxdir;
        sensors(k).xdir=sensors(k).xdir./norm(sensors(k).xdir);
        sensors(k).ydir=chydir;
        sensors(k).ydir=sensors(k).ydir./norm(sensors(k).ydir);
        sensors(k).zdir=chzdir;
        sensors(k).zdir=sensors(k).zdir./norm(sensors(k).zdir);

end

%------------------------------------------------------------------