Need help in filtering ECG (R-peaks) from Head signal recordings

I am kind of new to signal processing. I am working on a code to detect ECG (R-peaks) from the head recordings. Various research papers have suggested the usage of bandpass filter (4Hz-20Hz , 8Hz-20HZ) for QRS complex. However I would just like to filter the R-wave only from the head recordings. In my code I hv used IIR butterworth bandpass filter with 4HZ-20Hz, it works almost all the time for chest ECG but not for head-ECG(as u can see from my attached 4 sample recordings: asitrest, ksitrest, ositrest, tsitrest, jsitrest.

1)Therefore, please suggest me the usage of appropriate frequency range for head ECG-R peak and also appropriate filter configuration. 2)If the head ecg is corrupted or fall in same frequency range with other signals from the head such as eeg,eog,emg & etc, please propose a solution to just extract just head ecg from this head recording. Code example will help me alot. Thanks.

Answer 1

[Abhishek Ballaney]

https://in.mathworks.com/help/wavelet/ug/r-wave-detection-in-the-ecg.html

[Kahuthaman Silvadorai]

Dear Abhishek, thank you for your suggestion on using wavelet. However R-wave detection using wavelet may not be as straight forward for the head recordings. With current filter configuration that I am using, the feature of R-wave is not always visible in the head recordings(sometimes visible and most of the time is not visible). In my opinion, we may need to improve the current filter configuration first using the right frequencies and filters (correct me if I am wrong) before thinking about wavelet. Try running my code and you will understand what I am trying to say. Attached are some screen shot of the waveform of head recording and chest-ecg from my code for your viewing.