Neuromonitoring (Live Signal Monitoring)

Neuromonitoring, in a research recording, is the live observation of the neural data as it is acquired — per-channel signal quality, spikes, field potentials and event-aligned responses — so that the state of the electrode and the preparation is known during the session rather than discovered in analysis afterwards. In the clinic the same word names intraoperative neurophysiological monitoring, which uses EEG, EMG and evoked potentials to check nerve, spinal cord and brain function during surgery; the research sense keeps its purpose — act on the signal while it can still be acted on — and applies it to the electrode.

What is monitored follows from what fails. Site impedance ↗ and noise on each channel, because a broken trace, a dried site or a pulled reference ↗ shows as a channel out of family and can be corrected while the animal is on the rig. Unit yield and waveform, because a probe that has not reached its target, or has moved, shows it in the spikes before it shows it in the data. Event-aligned responses — a live PSTH, a live spectrogram — because a stimulus that is not evoking what it should is a protocol fault to fix in the first trials rather than the last. A recording session cannot be repeated; monitoring is how it is protected.

The requirement on the recording chain is that the data acquisition system ↗ streams the data to the host computer with low latency — about 10 ms on XDAQ and Smartbox — and the software reads it as it arrives. Radiens does this on any acquisition stream — XDAQ, Smartbox, Intan, Open Ephys, Plexon, TDT — with live signal quality in Allego, and its Vantage package extends the live view to spectral analysis, spike sorting and PSTHs during the recording.