I am currently doing analysis on Photoplethysmograph (PPG) data and I want to know the frequency (heart rate) at every time point so a windowed FFT might not be the best option. I am looking at wavelet to generate frequency and time information. I have been working with matlab example code however I have trouble determining what is the best wavelet to use for this application. I do now know much about wavelet. Does the wavelet used being dictated by the shape of my signal. In my case PPG signal which looks like this:
Or some other consideration is needed when choosing wavelet? How critical is the choice of wavelet?