Happy Command Outputs-respiration

Hi!

After a recent reinstallation of the rapidtide package, I noticed a new output file in my results: …desc-sliceresrespfromfmri_timeseries. I infer from the name that this is an estimate of the respiration waveform, which would be extremely beneficial for my work, as I often use datasets that lack dedicated physiological recordings.

Before I incorporate this new output into my analysis, I want to ensure I properly understand the methodology behind it. I’ve looked through the documentation but haven’t been able to find details on how this respiration signal is derived from the BOLD data, maybe I am missing something.

For context, this is the command I am currently using: happy xxx_bold.nii.gz xxx_bold.json dir/data_happy_out/sub-xx --cardcalconly.

I use happy version 3.0.8 and work in a conda environment in Ubuntu.

Could you please point me to any documentation, publications, or provide a brief explanation of the algorithm used to generate the sliceresrespfromfmri timeseries?

Best regards,
Elif Can