At Getinge, the sample size is determined mostly from the risk index. Since Getinge’s main acute therapy product is Intra-aortic balloons the risk index significantly changes the sample size while running a protocol. Recently, I was helping a senior engineer deal with a CAPA on IAB leaks within the tip seal. We wrote up a protocol which had to test a sample size of 300 IABs for a leak and pull test. If one out of the 300 IABs failed either of the tests, then it would be a major problem. The risk of having a leak on a class three medical device is not something that is taken lightly. The fact that the probability of more than one leak will result in a greater sample size to account for the high risk index.