I have completed my Masters in Biomedical Signal Processing. I have worked on ECG signal processing in Matlab as well as Python.
ECG signal processing can be done in 3 stages
1. Signal Filtering and Enhancement : Removal of noise from raw ECG acquired from ADC in your Raspberry pi
2. R peak Detection : There are various R peak detection algorithms like the Pan and Thompkins algorithm which detects the R peaks in ECG signal.
3. Morphological feature extraction : In this phase we extract useful features from the ECG signal like the R peak amplitude , Duration of the ECG wave amplitude of P wave , slope of the P wave ect.