They reconstructed the senario with a dog on the table instead of a human. The strange signal had disappeared. After a fortnight of testing, suddenly the mysterious signal reappeared. Examining the scrubber, they found that it was leaking 1A into the Earth leads. Because this was an internal flow through the body it was enough to produce ventricular fibrillation.
Hospitals now have GFCIs, and other protective devices.
Circuit Breakers and Fuses Circuit breakers protect against too much current There are three main commercial types. Domestic Sockets and Plugs When connecting wires at the back of plugs and sockets, remember that the connections are mirror images of the front. You should make very sure that the active and neutral are not interchanged, because any slight fault may leave the metal frame of an electrical device at high potential rather than neutral potential. You may feel safe to work on the electricals by pulling out all the fuses. Always check for potential differences before handling anything electrical.