Hi, all!
Now I have computed the Lead Field matrix using brainstorm, next I want to compute the MEG signal using forward model, but I have a question: The MEG signal has different unit on two sensor types: T for magnetometer and T/cm for gradiometer, does the lead field matrix have the same unit on this two different sensor types, if so, how can I to do the units thansformation?
Thanks for all!
I am not sure what you are trying to achieve exactly but there is a simulation tool in Brainstorm that takes care of everything in that regard (compute sensor time series from simulated sources). But yes, the lead field matrix is scaled to the proper units so that when multiplied by current source densities, it yields sensor measures with the proper units.
@hyb,
Check the Simulations tutorial, there is a section on simulating MEG/EEG from sources.
https://neuroimage.usc.edu/brainstorm/Tutorials/Simulations
In addition, the code related to these simulations is:
https://github.com/brainstorm-tools/brainstorm3/blob/master/toolbox/process/functions/process_simulate_recordings.m
Very thank for replying, I wnat to multiply the lead field matrix by current source densities, but I'm not sure the unit of lead field matrix on different sensor types, because the different sensor types have different units.
Very thanks! But I want to multiplt the lead field matrix by current source densities that I simulated, so I cares about the unit of lead field matrix on different sensor types.