Abstract

Apparatus for hemofiltration is disclosed, including a reverse osmosis module for purifying an impure supply of water, a container for adding concentrate thereto and preparing a replacement liquid, a semipermeable hemofiltration membrane filter for filtering the supply of blood and the replacement liquid in order to produce an ultrafiltrate stream and a filtered blood stream from the supply of blood and a filtrate stream from the replacement liquid so that the filtered blood and filtrate streams can be mixed and returned to the patient. An apparatus and method are also disclosed for monitoring fluid filtration in a semipermeable filtration membrane filter including a fluid inlet for supplying the fluid to the filter for contact with the semipermeable membrane to produce a filtrate therethrough, a fluid outlet for withdrawing the fluid from the filter subsequent to such contact, a filtrate outlet for withdrawal of the filtrate from the filter, a recirculation loop for returning the fluid withdrawn from the filter back to the fluid inlet, an indicator supply for adding an indicator which will not normally pass through the semipermeable membrane to the fluid in the recirculation loop, and a detector associated with the filtrate outlet for detecting the presence of the indicator in the filtrate stream.