LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Biosignal filtering

Hello,

 

I try to use Biosignal filtering from Biomedical Toolkit. Unfortunately, I am not able to set the filter as bandpass between 0,5 and 100 Hz. My sampling frequency is 200 Hz. 

Capture.JPG

Thank you,

Daniel

0 Kudos
Message 1 of 5
(912 Views)

You might be "doing something wrong", but it is difficult to guess what this might be without your posting your code so we can see what you are doing.

 

What do you know (from Signal Theory) about sampling frequency, total sampling time, # of points sampled, and the maximum and minimum frequency present in your signal?  [I'm guessing the answer is "not very much", as you specified a band-pass of 0.5 to 100 Hz and a sampling rate of 200 Hz -- do you see what is curious about this?].

 

Bob Schor

0 Kudos
Message 2 of 5
(901 Views)

I already solved it. Thank you for the inspiration what could be wrong. 

0 Kudos
Message 3 of 5
(893 Views)

Hi,

 

May I know how you resolved it? I am facing the same issue. Not sure about the frequency of the incoming bio signal.

 

Thanks,

Geetha

0 Kudos
Message 4 of 5
(127 Views)

Read THIS! 

 

Now we need to speak about Nyquist Frequency and Frequency Resolution

 

Frequency resolution (the smallest change in Frequency that can be detected) is 1/ record length.  Basically you need 2 seconds of time record to get 0.5hz resolution.   To detect DC you need an infinite time.

 

The Nyquist Frequency is 1/2 of the sample Frequency e.g. if you sample at a constant 1khz you can detect frequencies up to 500hz without aliasing (Frequency components greater than 500hz will be "Folded.")


"Should be" isn't "Is" -Jay
0 Kudos
Message 5 of 5
(106 Views)