Re: [Openeeg-list] FM EEG signal recommendations

[Oren T. <ore...@hi...>]

On Mon, May 12, 2003 at 10:08:48AM -0400, Joe Street wrote:
> >An EEG signal to be transmitted as an FM signal should be low-pass 
> >filtered to a Bandwidth of <200Hz. This filter need not be particularly 
> >sharp as the signal will be filtered later with a high quality software 
> >digital filter. The signal should have any DC bias removed by a filter
> >with a corner frequency low enough not to remove any significant 
> >content.
> >
> Hey guys while you are working on SCEEG you may want to give 
> consideration at the design stage to revising the analog design to 
> extend to DC.  Researchers in europe have become very interested in what 
> they call 'slow cortical potentials'  or SCP. These are signals which 
> change over a period of 300 msec to several seconds and are measured 
> using DC coupled amplifiers.  

This is an interesting application for the ScEEG because it has a
potentially very large dynamic range - well over 90db. How much of a DC 
offset can I expect relative to the amplitude of the AC signal? That is,
how many dbs of dynamic range will be "wasted" on encoding the DC?

	Oren