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hi all, i'm doing a project in preprocesing biosignals. if i'm given with a signal,how will i find out the cut off frequency? is it possible only by looking into the power spectrum.is there any formula(given only the sampling frequency)? kindly help.
thanx in advance
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cut off frequency
Started by ●March 25, 2004
Reply by ●March 25, 20042004-03-25
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Hi Vani,
Most biosignals tend to be low
frequency in nature, making them an interesting challenge to
process. Because they tend to be low frequency, they can very easily
be corrupted by unwanted interference e.g. mains supply or other
biosignals. As in most things, you must have a good idea of what you are
trying to achieve. Preprocess a signal, for what
purpose?
I suggest you use the SPTOOL feature of Matlab to
get started with, as this requires little knowledge of Matlab. This
will allow you to view your data, look at the spectrum and apply some
filtering. One point
to remember you must know the sampling frequency of your data acquisition, as
this will determine all the initial design parameters for your signal
processing.
As for cut-off frequency, if this is in relation
to a filter you want to design, you probably need to look at the
unprocessed spectrum first to see where the activity is
present.
As was suggested in a previous posting to this group,
the more information that's provided, the better the
response.
Best regards,
Jeff
======================
Jeff Winter
Snr Design Engineer
Aeroflex
www.aeroflex.com
-----Original Message-----
From: vani chezhiyan [mailto:v...@yahoo.com] Sent: Thursday, March 25, 2004 9:36 AM To: m...@yahoogroups.com Subject: [matlab] cut off frequency
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