Also known as an artificial kidney, dialyzer, or hemodialyzer; a machine used for dialysis that takes over the function of the kidneys when they are unable to filter toxic waste products from the blood. If the kidneys fail, toxic substances in the blood can accumulate and cause ureimia, which, if untreated, leads to death. Dialysis can be a lifesaving procedure when the kidneys are incapacitated by disease.