artificial kidney

artificial kidney mechanical device capable of assuming the functions ordinarily performed by the kidneys. In treating cases of kidney failure a tube is inserted into an artery in the patient's arm and blood is channeled through semipermeable tubes immersed in a bath containing all the normal blood chemicals except urea and other metabolic waste products. Since the concentration of harmful metabolic wastes are higher in the blood than in the bath, they pass through the walls of the tubes into the bath and purified blood is returned to the body. This process of blood purification, called hemodialysis (see dialysis ), is continuous or intermittent, depending on the residual kidney function in the patient. Kidney transplants usually make hemodialysis unnecessary.

kidney machine (artificial kidney) Equipment designed to remove toxic wastes from the blood in kidney failure. Plastic tubing is used to pipe blood from the body into the machine, where waste products are filtered out by dialysis.

dialysis Process for separating particles from a solution by virtue of differing rates of diffusion through a semipermeable membrane. In an artificial kidney, unwanted molecules of waste products are separated out to purify the blood. Electrodialysis employs a direct electric current to accelerate the process, especially useful for isolating proteins.