Hello,
I faced a strange warning and channel location problems when importing snirf files derived from Aurora NIRSport2 device.
Let’s proceed in order.
- directly from the snirf file that Aurora returns, when importing, several warnings appear, like:
- Warning: SNIRF format doesnt contains source or detector name. Name of the channels might be wrong
- Warning: Unknown unit mV for data type raw. The scaling of your data might be wrong
- Time vector for auxilary measure GYRO_Z is not compatible with nirs measurement (same warning even with the other GYROs and ACCELs)
I tried correcting the amplitude by scaling wavelengths values by a factor of 0.001, but I don’t know if it’s the right solution. The objective was to derive sources activity in various ROIs, and the scale of the reconstructed signal feels kinda of, being in the range of kMol/L
Moreover, first N seconds of reconstructed signal is in invalid scale.
For this snirf file, tho, channel location looks good, even tho the first warning didn’t seem to find channels info.
- The original snirf files contained events I was not interested in, from which I had to derive true events. So I passed from mne and mne-nirs in order to configure a new snirf file with correct events (I know I can load csv event files, I developed that option later on). I tried saving the new snirf file, with only the events changed, with and without the option optode_montage, but when loading the new snirf, channel configuration is wrong.
Importing the file, however, did not return previous warnings, except for:
- Warning: Unable to read the Measurement Time
Can someone explain to me what is happening? Which file should be used?
Thanks in advance,
Luca