Detecting patterns in waves

Question

I\'m trying to read a image from a electrocardiography and detect each one of the main waves in it (P wave, QRS complex and T wave). Now I can read the image and get a vector li

Answer 1

Are those other two sharp peaks and valleys also qrs complexes?

Off the top of my head, I think what you need to do is calculate the slope of this graph at each point. Then you also need to see how quickly the slope changes (2nd derivative???). If you have an abrupt change then you know you've hit some kind of sharp peak. Of course, you want to limit the detection of the change, so you might want to do something like "if the slope changes by X over time interval T", so that you don't pick up the tiny bumps in the graph.

It's been a while since I did any math... and this seems like a math question ;) Oh, and I haven't done any sort of signal analysis either :).

Just adding another point. You can also try signal-averaging I think. For example, averaging the last 3 or 4 data points. I think you can detect abrupt changes that way too.