Abstract: A membrane plasmapheresis system introduces a flow of whole blood subject to a predetermined inlet pressure into a fluid path across a membrane which is suited for filtering the plasma from the whole blood and across which a predetermined pressure drop occurs. The plasma-poor blood is conducted from the membrane subject to a determinable plasma-poor blood pressure. Likewise, plasma filtrate is conducted from the membrane subject to a determinable plasma-filtrate pressure. The conduction of plasma filtrate is metered in response to the existent plasma-poor blood pressure to achieve and thereafter maintain substantial equilibrium between the plasma-poor blood pressure and the plasma filtrate pressure. A substantially constant transmembrane pressure can thereby be maintained at a level below which hemolysis occurs.

Abstract: This invention relates to a method of forming porous membranes from thermoplastic or polymeric materials and to membranes so formed.

Abstract: A fluid flow control device comprises first, second, and third fluid conduits. The first and second conduits are adapted to communicate with separate sources of pressurized fluid. The third conduit includes an inlet portion in direct flow communication with the first conduit and an outlet portion communicating with the atmosphere. A flexible wall forms an interface between portions of the second and third conduits. In response to fluid pressure fluctuations in the second conduit, the flexible wall simultaneously meters the flow communication through both the inlet and outlet portions of the third conduit. The fluid pressure in the first conduit is thereby elevated until substantial equilibrium with the fluid pressure in the second conduit occurs.

Abstract: A fluid flow control device comprises first second, and third fluid pathways. The first and second pathways are adapted for communication with separate sources of pressurized fluid. The third pathway is coupled in flow communication with the first pathway and includes a flexible wall which forms an interface with a portion of the second pathway. The flexible wall meters the flow communication between the first and third pathways in response to fluid pressure fluctuations in the second pathway. The fluid pressure in the first pathway is thereby elevated until substantial equilibrium with the fluid pressure in the second pathway occurs, and is thereafter continuously adjusted in response to subsequent fluctuations of fluid pressure in the second pathway to maintain this condition of substantial equilibrium.

Abstract: A plurality of lengths of fibers may be disposed into a sheet-like array with the fibers being spaced from each other and defining channels therebetween. A pair of membranes is brought into adhering relation with opposed sides of the fibers of the sheet-like array to form a multichanneled flow device.

Abstract: A diffusion membrane unit comprising: in a first embodiment, a planar arrangement of parallel separate capillary membrane tubes and junction lines of adhesive material extending continuously across said parallel membrane tubes and continuously along the entire length of said arrangement; and in a second embodiment a plurality of planar single-layered arrays of parallel capillaries defining out of phase sinuous paths.

Abstract: The method of repairing leaks in a bundle of hollow capillary fibers of a diffusion device disposed in a housing comprises temporarily sealing one end of the bundle of fibers, applying a curable sealant paste to the other end of the bundle of fibers, and then applying a suction pressure to the flow path which passes through the bundle on the exterior of the fibers. Wherever a hollow fiber has a leak, the suction pressure will be transferred to the interior of the fiber, to individually cause the fiber to suck the curable sealant paste into its interior, thus blocking the fiber and preventing flow through it.

Abstract: There is disclosed herein an apparatus and method for preparing a continuous, hollow, and semipermeable filament for use in a dialyzer which includes a plurality of substantially-equal-length open-ended fibers.The apparatus includes a body having a supply spool of filament and a take-up reel having at least two radially-spaced support means about which the filament is wound. Drive means rotate the take-up reel and a filament guide is provided for laterally positioning the filament on the support member so as to prevent close packing of the filament windings. The take-up reel includes a winding plate for carrying the filament support means and hub-and-locking means for releasably mounting the winding plate on the machine.The method includes winding the filament from the spool onto the take-up reel; grasping each of the sections of filament between the support means; and cutting the filament adjacent the support means so as to form a plurality of bundles of open-ended fibers for use in a hollow fiber dialyzer.

Abstract: There is disclosed herein an apparatus and method for preparing a continuous, hollow, and semipermeable filament for use in a dialyzer which includes a plurality of substantially-equal-length open-ended fibers.The apparatus includes a body having a supply spool of filament and a take-up reel having at least two radially-spaced support means about which the filament is wound. Drive means rotate the take-up reel and a filament guide is provided for laterally positioning the filament on the support member so as to prevent close packing of the filament windings. The take-up reel includes a winding plate for carrying the filament support means and a hub-and-locking means for releasably mounting the winding plate on the machine.