title: Algorithm to analyse photoplethysmogram (PPG) signal in python
body: <p>I want to calculate the Heart Rate Variability using a PPG. I have the raw PPG values and I actually don't know where to go. </p>
  
  <p>I would like to be able to do this in Python. If anyone could be me the steps to doing this it would be great.</p>
  
  <p>Cheers in advance<a href="https://i.stack.imgur.com/890Hk.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/890Hk.jpg" alt="sample PPG"></a></p>