Equivalent volume replacement device for a first liquid by a second liquid, in particular: for haemodialysis in artificial kidneys

摘要

A principle fluid (such as haemofiltrate, plasmafiltrate, or purge liquor from body cavities) is accurately replaced by an identical volume of replacement liquid (such as infusion soln., purge soln., substitute plasma). The replacement liquid is contained in a very flexible container (such as plastic bag or folded bag) and is displaced out of action of the principle fluid on this bag acting in a closed circuit. A closed, rigid container contains two such flexible bags. One is completely full and the other completely empty. As liquid is abstracted, it is pumped into the empty bag and displaces an identical volume of the replacement liquid. In this way an identical volume of liquid is displaced to the patient etc.