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Designing a system of two filers(Band Stop and High Pass)

by coolrp
Tags: designing, filersband, pass, stop
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Nov22-12, 12:04 PM
P: 14
I have no idea what is to be done. Please help!

I do not how am I supposed to proceed/begin as well.

The zip files contain a data collected from an ECG machine and the pdf has the problem statement.

Any kind of help would be much appreciated.

Attached Files
File Type: pdf Project Assignment.pdf (137.3 KB, 10 views)
File Type: zip ecg (214.9 KB, 0 views)
File Type: zip ecg data (143.3 KB, 0 views)
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Nov22-12, 02:11 PM
P: 390
It's an assignment! We can't help you right away. You have to follow homework help guideline to show that you have approached a solution yourself.
Nov22-12, 02:37 PM
P: 14
actually I am not able to understand what am I supposed to do.

I mean, okay, i copied the signal in MATLAB and plotted it, it comes out as shown in the figure. I have to design two filters, band stop and a high pass filter to attenuate the noise in the signal.

I know that the bandstop specifications include first/second pass/stop band frequencies, attenuation gain etc etc, but how do i go about calculating them??

how am i supposed to use the sampling, 12bit A/D, amplification of data etc to find the specifications if at all these are to be used?

i dont know where to begin!

Nov25-12, 03:52 PM
P: 14
Designing a system of two filers(Band Stop and High Pass)

just give me something to start with...
Nov25-12, 04:24 PM
P: 14
can you please tell me how do I filter a signal? I mean the signal output as given in the attached file is plotted. Now if i design a filter using FDA Toolbox, how am i supposed to test that filter for this signal input?
Nov25-12, 05:46 PM
P: 14
i didn't ask to help me understand how to read the ECG! I merely asked how are to determine the filter specifications.

As for the my work, I did the following, since the sample includes 150, 000 samples and we dont really need all of them. Since the sampling freq is 1000Hz, we can take up any number of samples above that. I took 1024 samples and took the fft of the sample, and plotted the abs value graph and got the signal in frequency domain and now the powerline is clearly visible at 50Hz.
the graphs:

so the passband and stopband frequencies are around 50Hz as in these graphs?
Nov25-12, 05:49 PM
P: 14
I have a pretty good idea about filters, what I am not very good is MATLAB and dude, seriously, this post wasn't binding on you to answer!!

Fine, I suck at practical implementation of theoretical concepts but dude, chill! Yeah, I am pretty good at theoritical concepts (and that doesn't mean book learning if you think its anywhere close to that)!

Thanks for your help anyways! I am surprised, you thought that the second diagram was a partial filtered graph of the first. Its an ideal ECG signal!
Nov25-12, 05:54 PM
P: 14
Quote Quote by yungman View Post
You filter a signal using electronic filters. In your case, it would be active filters. This is an article on designing active filters.

Again, how do you get into this class without the basic knowledge of filters?
I meant in MATLAB, the FDA tool is a tool in MATLAB to design filters! But it only creates a filter as per my specifications, how do i test it with an input is what I asked? Any idea about that?
Nov25-12, 06:00 PM
P: 14
Quote Quote by yungman View Post
Dude, I see you are very desperate in getting help, but you have not put in any effort in suggesting any solution and you are rude. No wonder no body help you here. You are on your own.
I wasn't the one who was taking personal shots.. I just asked for how do I decide filter specifications from a given graph...You don't even know me and you could were questioning my credibility..

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