Dear Shahin,

It should be possible to combine ECG and respiratory data in a single run of PhysIO. Your error message looks more like an issue with the function filtfilt. Could you paste the full error message, please?

Also, could you type "which filtfilt" in the Matlab command window to make sure you have the Matlab signal processing toolbox installed and that it's not using the one in SPM?

As this forum is not regularly monitored, would you be able to post on github in the future, please?

https://github.com/translationalneuromod...