ECG electrode current leakage

It turns out that for our ECG system we are over the limit for leakage
current.  We have some current limiting resistors that go in between
the electrodes and amplifiers but that doesn't seem to be doing the
trick.

Does anyone out there have any experience with sensors on the human
body and how to limit the current?

Also what would be an easy way to set something up quickly to alllow
me to verify the leakage?

-Brad