Abstract: A membrane pouch, for rehydrating sterile intravenous and other solutions for non-sterilized fresh water, has a double bag construction. An inner bag made of semipermeable membrane material holds the sterile solutes to be rehydrated. The membrane material is permeable by water but impermeable to contaminants and a large molecular weight solute contained in the bag. An outer waterproof bag encloses the membrane bag and serves as a container for fresh water. Each bag has a sealable valve for providing access to the interior thereof. A high molecular weight dye located in the outer bag provides a visible indication of the existence of any discontinuity in the membrane bag. A low molecular weight, water soluble, non-toxic substance having a high osmotic pressure can be placed inside the membrane bag to accelerate the osmotic transfer of sterile water from the outer bag into the inner membrane bag.

Abstract: A method and apparatus of processing biological fluids by adding or removing preservatives or simply removing water comprises providing a bag of semi-permeable membrane which contains the biological fluid and bathing the bag with dialysate having controlled osmolality. The preservative or water can thus be removed or added to the bag directly through the semi-permeable membrane by controlling the osmolality of the dialysate without exposing the biological fluid to contaminants. In the case of whole or components of blood, the blood or blood components can be collected in the bag, processed for preservation, and prepared for use then administered, all in the same bag.

Abstract: A bag for containing blood or blood components comprising a closed container made of material which is permeable to a cryoprotective agent, such as glycerol, which may be added to the blood or blood components directly through the permeable walls of the blood bag. The cryoprotective agent protects the blood or blood components when the blood is frozen for storage and the cryoprotective agent can thereafter be removed through the permeable walls of the container without contaminating the blood therein. An apparatus and process is also disclosed for the cryoprotective agent to be added or removed from the blood bag using electric current, hydrostatic pressure, centrifugal force or osmosis.

Abstract: Disclosed is a method of hemodialysis and a modification for existing hemodialyzers to facilitate use of the method. A highly porous membrane is utilized in a single pass hemodialysis system. The membrane is freely supported, such that it distends in use to maintain a constant transmembrane pressure over its entire surface. The modification to existing dialyzers includes the use of a highly porous membrane, in combination with a transmembrane pressure sensor, which controls the dialysate output flow to maintain a precise transmembrane pressure.