First thing is to make sure software is not the issue. Here's the steps:
- Make sure to always use most up to date software.
- If this is the case, next step is to make sure there's no data loss happening during impedance monitoring. Please look at this article (linked) on how to detect data loss during streaming.
If data loss is happening and impedances are flickering, this is expected. You need to ensure good Bluetooth connection before going to the next steps.
1. If Bluetooth connection seems fine, next you need to check impedance on the reference. Make sure that it's low and stable.
For impedance connection, you need to have (at least) 3 electrodes mounted - ground, reference and one other measuring electrode (e.g. Fp1)
2. If reference seems fine and you still have electrodes showing NC/high impedance, check if you can see an EEG signal on those electrodes.
It could happen that the impedance measurement is failing for some reason, but you can see EEG on the electrode.
If the electrode is flat, then there's really no contact.
3. Lastly, you can do a bucket test if the previous steps are not met. Put the entire cap in a bucket of water + add a bit of salt to increase conductivity. Observe impedances on electrodes that give you trouble.
Only the cap with electrodes should be placed in the water! Amplifier + amp casing should be kept outside of the bucket, wrapped in a towel for splash protection.
→ You can let us know your findings and we'll take it from there! support@mbraintrain.com