Abstract: An exchanger and method for manufacturing the same are disclosed. In one embodiment, the exchanger crimps a hollow fiber bundle along a length of a cylindrical case in at least two radial positions. At least one crimp is between an inlet port and an outlet port of a blood conduit. Preferably, the cylindrical case has two portions with different radii so that when the two portions are mated to enclose the hollow fiber bundle, crimping is achieved. In this way, shunting of blood is avoided by being forced to pass a crimped position between the inlet and outlet ports to more evenly distribute the blood among the fibers of the bundle. In another embodiment, a method for making an exchanger includes filling a chamber, integral to the exchanger, with uncured potting material. The exchanger is spun to distribute the uncured potting material about open ends of an encasement. After curing, a portion of the potting material and the hollow fiber bundle are trimmed away.

Abstract: The integrity of a microporous membrane within a mass transfer device such as an oxygenator is tested simultaneously with applying a biocompatible surfactant to at least the blood-contact surface of the membrane. The membrane integrity test contacts both sides of the microporous membrane with a conductive fluid to establish an electrical circuit. An electrical signal is then applied to the circuit and a measurement is taken of the test voltage across an impedance in the circuit. The value of the test voltage is used to determine the conductivity and thus the integrity of the membrane. The biocompatible surfactant is mixed with the conductive fluid used in the electrical integrity test and has an affinity for the microporous membrane material so that a durable biocompatible coating is applied to at least a portion of the microporous membrane.