Practitioners of the mechanical healing arts have been compared to doctors and surgeons. There are similarities, to be sure. However, doctors only have to service one make that is available in just two different models. Doctors usually bury patients that have been declared dead on arrival (DOA). Owners and next of kin demand that we revive most of our DOA patients. At least we have the luxury of stopping for a cup of coffee in the middle of a transplant operation.