need digital filter toolkit to make a notch?

[Pells]

Hey! Do I need to have the digital filter toolkit to make a digital notch filter or It works with just my student edition 8.0?

[Pells]

doesn't anybody know? is it possible to make a notch filter in student version 8.0 or do I need some kind of toolkit for that?

[Barp]

Pells,

The student edition of LabVIEW is equivalent to the Full Development System and you have access to all the Analysis Functions of LabVIEW, which include a lot of Filtering options for you.

The notch filter is a band-stop filter with narrow stopband. So you can use "Digital IIR Filter" (Signal Processing>>Waveform Conditioning) and change the option to stopband (you are using waveform datatype). If you have a 1D Array, there is a whole pallette to choose in Signal Processing>>Filter. If you are acquiring and filtering at the same time, the Point-by-point function is a better option, which you can find in Signal Processing>>Point-by-point>>Filter.

Hope this helps!

Barp - Control and Simulation Group - LabVIEW R&D - National Instruments

[marp84]

can tell more details about that?

do you know what is the lower and higer cut-off frequency of this filter (notch filter) to eliminate the noise from ecg signal?

[johnsold]

Usually notch filters have a center frequency and a width (Q) parameter while bandstop filters have upper and lower cutoff frequencies.

If you are using a notch filter, set it to the frequency of your interfering signal.  There is no universal standard for ECG.  Most likely your interference is at the power line frequency (50 or 60 Hz depending on what part of the world you are in).  If you have broadband noise as opposed to interference, a notch filter will be of little use.

Describe your "noise" better or post what you have tried along with a sample of your data.

Lynn