Files for "Getting started with Cerca OPM data"

If there are any issues, please don't hesitate to contact Ryan Hill (ryan.hill@nottingham.ac.uk or ryan@cercamagnetics.com)

1) Getting started with Cerca OPM data.dox 	- similar tutorial to the Getting started with FieldLine OPM data.

2) Getting_Started_with_Cerca.m			- example script for the tutorial in 1).

3) Braille_example_data				- folder with example data for a braille task using the Cerca system.

- This tutorial uses a .fif file that has already been created. Tools to also load .cMEG files into FieldTrip are being developed.
- This task involves two braille stimulators being placed on the left and right index finger. These present a pattern using plastic pins.
- The pins were presented for ~0.37 seconds with an interval of 1 second between each stimulation.
- In the .fif file, the onset of the stimulation is given by the "Bra" channel, while the "Lef" and "Rig" channels indicate whether it is the left or right finger being stimulated.

For when the .cMEG reader is working:
- In the .cMEG file, the channel order is given by the "_channels.tsv". Here, the trigger channels are oddly labelled due to how this particular DAQ is wired. "Trigger 1 [Z]" is the "Bra" channel, and "Trigger 2 [Z]" and "Trigger 3 [Z]" are the "Lef" and "Rig" channels respectively.
- the "_HelmConfig.tsv" lists which slot each sensor was in and their respective positions and orientations in the helmet CAD space.
- the "_SensorTransform.tsv" has the transformation matrix that maps the sensor positions and orientations to either a head digitisation or an anatomical MRI. If no coregistration has been done, this is simply a 4x4 identity matrix.

ADDITIONAL FILES
- An anatomical MRI for this participant is provided: 11766.nii
- Two digitisations are also provided: 1) participant wearing the helmet (11766_hnf.ply), 2) participant with no helmet (11766_head.ply)
- The CAD file for the purple adult large helmet: adult_L_m.ply
These files should allow you to perform co-registration as described in Figure 2b of Hill et al. 2020 (https://doi.org/10.1016/j.neuroimage.2020.116995)