low pass filter with windowing method

dollydolly
edited February 2008 in Science & Tech
hi everyone,
im doing an assignment about developing an adaptive notch filter for the removal of 50hz noise from an ecg signal..im really not familiar with matlab but im learning..after i read about filters i decided to use low pass filter with windowing method..now ive tried tis low pass filter
fsamp = 60;
fcuts = [5 10];
mags = [1 0];
devs = [0.05 0.01];
[n,Wn,beta,ftype] = kaiserord(fcuts,mags,devs,fsamp);
hh = fir1(n,Wn,ftype,kaiser(n+1,beta),'noscale')
after that i really dont know how to continue the development..please guide me.
awaiting for ur reply
dolly

Comments

  • shwaipshwaip bluffin' with my muffin Icrontian
    edited February 2008
    1) an adaptive notch filter is nowhere near a LPF based on the windowing method.
    2) i can almost guarantee you don't want to use a LPF
    3) ??
    4) Profit.
  • dollydolly
    edited February 2008
    shwaip wrote:
    1) an adaptive notch filter is nowhere near a LPF based on the windowing method.
    2) i can almost guarantee you don't want to use a LPF
    3) ??
    4) Profit.


    sir,can i give the input signal to the low pass filter and then directed to kaiser to eliminate the noise..is my method is correct?
  • shwaipshwaip bluffin' with my muffin Icrontian
    edited February 2008
    why are you low pass filtering the signal at all?
  • dollydolly
    edited February 2008
    what i understoodd was like that.that means i just can use the low pass filter isnt it..how i should call the signal to the low pass filter?
  • shwaipshwaip bluffin' with my muffin Icrontian
    edited February 2008
    do you have the filter design toolkit? Try typing fdatool, and if it brings up a gui, you should be able to figure it out with that.

    You want to create a notch filter, not a low pass filter. The idea is that you have 50Hz noise in your signal, so you want to get rid of just that noise without affecting the rest of the signal. If you use a low-pass filter, you will remove the 50Hz noise, but also anything above 50Hz.
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