A perfusionist operates extracorporeal circulation and autotransfusion equipment during any medical situation where it is necessary to support or temporarily replace the patient’s circulatory or respiratory function. The perfusionist is knowledgeable concerning the variety of equipment available to perform extracorporeal circulation functions and is responsible, in consultation with the physician, for selecting the appropriate equipment and techniques to be used. Source: Health Professions Career and Education Directory, American Medical Association [1/1/2007: new]