Hello! I have been analyzing the plethysmography (PPG) signal from the CHAT and Cleveland Family Study cohorts and was wondering if anyone knew what filtering was used when these files were converted to an EDF. While the pages say "raw," they look smoothed to me and was wondering if they pre-applied a filter (and which type if so) before making publicly available or if the device itself applies a filter. Any insight would be of enormous help!
Thanks for using the site. From what I understand, it's likely the data were preprocessed at the Nonin module (i.e., not at the time of EDF export), but I don't have any more details other than what Nonin puts on their website (e.g., https://www.nonin.com/products/oem3/).
Thank you for the quick response!