From: JBilderback (jiva_at_humboldt1.com)
Date: 2001-12-03 16:17:09
> It is more like 100 micro volts or more of noise riding on 5 micro
> volts of signal if you have a good strong signal. Look at the "real"
> data I posted on my website.
will try to get your app up and running to take a look.
> > restating the question: if there's say 5uv of high frequency noise
> > riding on a 100uv EEG signal then what is gained with 12-16
> > bit data sampling ??
>
> I'm not much of an analog guy, but according to most of the
> published acceptable standards for EEG, at least 12-bit
> resolution is required. According to EPTA the noise should
> be 2 mV per below.
>
> Noise: 2 m V peak to peak, 0.16--100 Hz
> Common Mode Rejection Ratio: greater than 80--100 dB
> Sampling Rate: minimum of 200 Hz, preferably 250--400 Hz
> Amplifier Dynamic Range: greater than ± 2 mV
> High Filter: 15, 30, 50, 70, 100 Hz (- 3 dB or preferably - 12 dB)
> Low Filter: 0.16, 0.5, 1.6, 5, 10 Hz (- 3dB)
> Notch Filter: attenuation ratio 1:20 at 50 and 60 Hz
> Sensitivity: 1, 1.5, 2, 3, 5, 7, 10, 15, 20, 30, 50, 70, 100 mV /mm
> A/D Conversion: greater than or equal to 12 bit ADC. The recording
> should be able to resolve activity down to 0.5 mV and as high as
> several millivolts without clipping.
I don't think the current project is this (evolving?) state of the art.
I haven't been paying close attention to the hardware status lately,
is the current project going to be completed or are the specs
going to dictate a newer design?
I, for one, would like to see a very inexpensive 2 channel
home-buildable design as at least one option from the
group.
OTOH ... I don't want to muddy up the waters for the folks who
have been working on the hardware for so long and would like
to see them be able to get their design to buildable stage.
This archive was generated by hypermail 2.1.4 : 2002-07-27 12:28:32 BST