Filtering ECG signal

[Plugmen]

Hello!

I have a problem with filtering ECG signal. I have only values of X (time) and Y (voltage) in excel file. Nothing more like signal equation. How can i filter this signal? I have to do it in python but my knowledge of signals is very bad. I will be very grateful for some tips. Thank you!

 

[D.A.(Tony)Stewart]

What kind of filter do you need?
LPF uses rolling average of more than adjacent cell.
Weighting adjacent cells gives a different filter response.

Audacity has better filters for WAV files. (free)
Parametric , LPF, HPF, notch, arbitrary, spectral analysis

In communication systems theory, we learn that the best filter is one that matches the signal content for passband in both amplitude and phase and matches the noise spectrum for band reject.
DO you understand what I mean or know how to do this?
THis gives the best SNR.
But in digital channels we must also consider inter-symbol interference for low phase error or jitter.

Are you using active guarding method or feeding the common mode signal back to a central 3rd electrode and twisting the wires to reject CM noise?
Or just twin leads with an IA? ( bad practise)

 

[andre_luis]

You first have to determine what are the artifacts that are polluting your signal, and then specify the filter requirements. In Excel you could use the VBA to do that, but as Tony mentioned you'll need an external tool to synthesize the equations.

 

[Plugmen]

I think that i should use LPF and HPF. Problem is that i have to filter this signal in python because it is my task in project.

 

[D.A.(Tony)Stewart]

If you record the signal as a WAV file in a PC with DC response but offset nulled in the audio amp. you can record with Audacity and do all your processing here. with GUI filters ( graphic equalizer etc) then hear it, shift the spectrum up an octave, measure spectrum etc.

or.... Analyze a short quiet WAVE file and insert your data in Notepad and import ECG signal and view it, play it, filter it or spectrum analyze it.