Generating empirical BOLD data

[Mike Miller]

Hello all,
I have fMRI imaging of patients with a disease. I am looking to simulate BOLD data using TVB to mimic these disease conditions. I suppose I would initially generate a simulation and then tune the parameters to match the empirical BOLD signal. Any suggestions as to how I can generate this empirical BOLD signal from my fMRI file which is a .nii extension?

Thanks,
Mike