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| Can
we adjust the filter settings on a BioSemi system ? |
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| Yes,
but only in software. |
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| With
the ActiveTwo, all filtering is digital. High-pass filtering (if
any) is completely performed in software, the hardware is completely
DC coupled. Low pass filtering is performed in the ADC's decimation
filter (hardware bandwidth limit), which has a 5th order sinc response
with a -3 dB point at 1/5th of the selected
sample rate, see filter graph. Further variable bandwidth limiting
(high and low pass) can be applied at will in software. |
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| Because
of BioSemi's unique setup with active electrodes, battery power
supply, and optic fiber signal link, 50 Hz interference is eliminated
from the recordings. Therefore, reverting to signal corrupting patches
like 50 Hz notch filters is never needed. |
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| The
completely digital filter methods used in the ActiveTwo (in the
ADC or by software) eliminates response differences between channels.
While the accuracy of analog filtering is compromised by component
tolerances (5% for typical filter capacitors), digital filtering
ensures completely equal frequency response for all channels. |
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| Click
here for information about adjusting the filter on older BioSemi
systems |
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