Wiz 140301 : Can the U-wiz do ultra low frequency?

Short answer is Yes.

A slightly longer answer is No.  Wiz yes, however BioExplorer cannot do the very very low frequencies that the Othmers use. BioEra can.

 

U /Q Wiz are _DC coupled_ devices. That is they measure all the sins right down to DC (0Hz).

We in fact modify them such that default operation is _AC coupled_ mode by removing the DC offset voltage. This has the effect of introducing an artificial low frequency cut-off at about 2Hz so that the signal looks more like the (well-behaved) Pendant EEG signal.

Each time the Wiz powers up, it comes up in the default _AC coupled_ mode and you need to specifically enable _DC coupled_ mode.

For the Q wiz, the button at the bottom of the unit has these functions:

–          Short press: references linked no/yes (off/green)  [this state is remembered between power cycles]

–          Long press (>2sec): AC/DC coupled (off/blue) [this state is not remembered between power cysles]

So if both _Linked References_  AND _DC coupled_, then Green+Blue = Aqua

 

Mental jog: Blue = cold = frozen = DC offset is not removed = any DC variation affects the EEG signal strongly

 

The colour indications are the same for the U-wiz, however the U-wiz has no buttons. For the Uwiz, Mode changes, linking references and AC/DC coupled must be done in the Wiz window in BioExplorer.

 

Other bits of information.

How to use:

–           If using ultra low, must use Ag/AgCl electrodes and even then wait a few minutes to allow electrodes to stabilise.

–          Start in default AC coupled mode then allow signal to look good. Then select DC coupled. If the trace is racing off the screen, then you haven’t waited long enough. This stuff is not easy and very artefact prone. Not for the home user IMO.

I don’t have an ultra low frequency BioEra design yet. Considering whether it is a good thing to do or not.