For information on the current George B. Moody PhysioNet Challenge, see:
http://moody-challenge.physionet.org/
Additional Challenge content:
Moody PhysioNet Challenges
Since the turn of the century, PhysioNet has run an annual Challenge in collaboration with Computing in Cardiology. More information on these challenges can be found here. The following is a list of past Challenges, with links to descriptions of the Challenge, associated open access data, open source code and resultant publications: