A search for *Online detection algorithms* would be a start. 

More information located on stackoverflow: [Peak Dection of measured signal][1]

[1]: https://stackoverflow.com/questions/3260/peak-detection-of-measured-signal%22Peak%20dection%20of%20measure%20signal%22 
 
A python implementation of a naive peak detection routine is to be found at [github][2]

[2]: https://gist.github.com/250860