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Figure 4 Coil control box showing the pneumatic foot pedal. The Magstim Rapid will not operate unless
the foot pedal is depressed.
Figure 5 The new coil control box with the pneumatic foot pedal removed and the new safety switch
installed. This box also contains added noise elimination circuitry that is described below. The button in
the top left corner switches between manual and computer control; manual control is useful for
debugging and experiments outside the scanner. The large red button will immediately disconnect the
coil when struck, this may be necessary if the subject has a seizure.
Noise Elimination
Noise inherent to TMS
The very function of the TMS critically interferes with the function of the MRI;
activation of the coils can create a field of up to two teslas at its focal point. This is on