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

  • Thread starter Thread starter coolrp
  • Start date Start date
  • Tags Tags
    Designing System
Click For Summary

Discussion Overview

The discussion revolves around the design of two types of filters, specifically a band stop filter and a high pass filter, to process data collected from an ECG machine. Participants express confusion about how to determine filter specifications and implement filtering techniques using MATLAB.

Discussion Character

  • Homework-related
  • Debate/contested
  • Technical explanation

Main Points Raised

  • One participant expresses a lack of understanding about how to begin the assignment and requests help with the problem statement and data provided.
  • Another participant reminds the original poster to follow homework guidelines and demonstrate their own efforts before seeking help.
  • A participant describes their attempts to analyze the ECG signal using MATLAB, mentioning the need to design filters to attenuate noise and asking how to calculate filter specifications based on the data.
  • There is a request for guidance on how to filter a signal and test the designed filter using the FDA Toolbox in MATLAB.
  • One participant shares their approach of taking a subset of samples from the ECG data and performing an FFT, noting the visibility of a powerline noise at 50Hz and questioning if this frequency corresponds to the passband and stopband frequencies.
  • Another participant acknowledges their theoretical understanding of filters but admits to struggling with practical implementation in MATLAB, while also expressing frustration at perceived rudeness in the discussion.
  • A suggestion is made to refer to an article on designing active filters, although it raises a question about the basic knowledge of filters among participants.
  • One participant expresses frustration at being perceived as unhelpful and defends their request for clarification on determining filter specifications from the provided graph.

Areas of Agreement / Disagreement

Participants generally express confusion and uncertainty about the assignment and the process of designing filters. There is no consensus on how to determine filter specifications or the best approach to implement the filtering in MATLAB.

Contextual Notes

Participants mention various aspects of the ECG data, including sampling frequency and the number of samples to use, but details on how these factors influence filter design remain unresolved. The discussion reflects differing levels of familiarity with both theoretical concepts and practical applications.

coolrp
Messages
12
Reaction score
0
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.

Thanks
 

Attachments

Engineering news on Phys.org
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.
 
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 don't know where to begin!
 
just give me something to start with...
 
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?
 
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 don't 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:
hrne2v.jpg

1fd45s.jpg


so the passband and stopband frequencies are around 50Hz as in these graphs?
 
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 theoretical 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!
 
yungman said:
You filter a signal using electronic filters. In your case, it would be active filters. This is an article on designing active filters.

http://www.ti.com/lit/ml/sloa088/sloa088.pdf

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?
 
yungman said:
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..
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 15 ·
Replies
15
Views
2K
Replies
3
Views
4K
Replies
9
Views
3K
Replies
14
Views
3K
  • · Replies 7 ·
Replies
7
Views
7K
  • · Replies 6 ·
Replies
6
Views
3K
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K