Abstract: A method of preshrinking a semipermeable membrane or blood bag of the type used in an artificial-kidney coil dialyzer, so as to prevent or minimize shrinkage of the membrane during sterilization of the dialyzer. The preshrinking method of the present invention includes the steps of passing the membrane through a humidity chamber in a free-hanging state and then into a warm air drying chamber. The amount of membrane shrinkage can be controlled by varying the residence time, the temperature and the humidity of the chamber. By preshrinking the membrane to approximate the amount of shrinkage which normally occurs during the sterilization, substantially all shrinkage during sterilization is eliminated.

Abstract: An elongated, flexible and embossed support member is disclosed herein for use in a coil-type artificial kidney dialyzer to support an elongated, flattened and tubularly shaped semipermeable membrane. The membrane is of cellophane or a cellulose derivative and has the characteristic of stretching further in the transverse direction than in the longitudinal direction. The support member includes an imperforate fluid-impermeable web having angle ribs on one side and skip ribs on the other side for positioning and supporting the membrane within the dialyzer. The angle ribs extend angularly from one longitudinal edge of the member to the other longitudinal edge and the skip ribs are arranged in longitudinal rows, with each row including a plurality of intermittently spaced skip ribs. The skip ribs are higher than the angle ribs and both sets of ribs are of a height effective to prevent the membrane from contacting the web.

Abstract: An elongated, flexible and embossed support member is disclosed herein for use in a coil-type artificial kidney dialyzer to support an elongated, flattened and tubularly shaped semipermeable membrane. The membrane is of cellophane or a cellulose derivative and has the characteristic of stretching further in the transverse direction than in the longitudinal direction. The support member includes an imperforate fluid-impermeable web having angle ribs on one side and high and low skip ribs on the other side for positioning and supporting the membrane within the dialyzer. The angle ribs extend angularly from one longitudinal edge of the member to the other longitudinal edge. The skip ribs are arranged in alternating longitudinal rows of high and low ribs with each row including a plurality of intermittently spaced skip ribs.

Abstract: A membrane diffusion device is disclosed which comprises flat, tubular, semipermeable membrane, and flexible, ribbed membrane support sheet positioned against said membrane and typically rolled up together into a coil. In accordance with this invention, a first set of membrane supporting ribs is disposed on one side of the support sheet with the ribs of the first set being disposed in longitudinal relation to the axis of the tubular membrane, the ribs of the first set also defining spaced apertures to permit fluid flow transversely across the membrane. A second set of membrane supporting ribs is disposed on the other side of the membrane support sheet at an angle to the tubular membrane axis.