TEE Probe Leak Test

Back in July 2013, one of the revisions to the IAC Standards and Guidelines included “the structural and electrical integrity of the transducer must be checked between each use, using an ultrasound transducer leakage tester.” This revision becomes effective December 31st, 2015. That’s great, but why do we have to do this? What is a leakage tester? How does it work? Where can I get one?