Abstract: Manufacture of bundles of at least 1000 semi-permeable hollow fibres for use in filters such as, e.g., blood, plasma and dialysate filters, and in artificial kidneys. One or more hollow filaments are wound onto a reel until the formed package contains the number of filaments required for bundle formation. After which the package is cut into fibre bundles of the desired length. The package is held in one place of the reel and a free end is introduced into a sleeve having a length which is a number of times that of the length of the fibre bundle in the final filter. The sleeve is cut into fibre bundles of the desired length.

Abstract: A binder for low density lipoproteins (LDL) consisting of sulphated polyvinyl alcohol which is cross-linked by the chemical or the physical route to a waterinsoluble product. The binder may be in the form of a hydrogel which is applied or not to a carrier or it may be present on the surface of a polyvinyl alcohol fibre which is preferably in the form of tape having a thickness of 0.1 to 2 .mu.m and a width of 0.5 to 6 .mu.m. The fibre shaped binder is prepared by successively cross-linking with an acidified aqueous solution of glutardialdehyde and sulphating with chlorosulphonic acid.

Abstract: An apparatus for purifying blood has a blood compartment and a clearance compartment separated by a semi-permeable membrane. The apparatus includes a device containing a cation exchange resin charged with metal ions whose phosphates are insoluble in water. Metal salts of iron, aluminum, zirconium, lanthanum, thorium and tin are deposited on a cation exchange material and the charged cation exchange resin is contacted with dialysis liquid. The process of treating blood with the dialysis liquid is also contemplated.

Abstract: The invention relates to a separating device, more particularly for hemodialysis, comprising a housing accommodating at least one bundle of a large number of tubular, selectively permeable membranes connected in parallel whose transverse dimensions are very small relative to their longitudinal dimensions. The ends of the membranes rest on supporting members in the housing. The membranes may be the walls of hollow fibers which divide the internal part of the separating device into a first medium space provided by the inside of the membranes and a second medium space inside the housing but outside the membranes. The medium spaces are each provided with an inlet and an outlet for respectively the supply and the discharge of a first and a second medium, which media can enter into exchange through the walls of the membranes.

Abstract: An examination of the human heart is carried out by means of ultrasound waves emitted by piezo-electric crystals. The crystals are inserted in a holder adapted to be placed on the body of a patient; they are arranged in a row and have parallel axes of radiation. The crystals are cyclically excited at a high scanning frequency, and the echo signals reflected by the heart walls and received by the crystals are displayed on the screen of a cathode ray tube to obtain a cross-sectional picture of the heart. In a modification of the invention, the holder comprises two or more rows of crystals radiating at different angles; in this case the echo signals related to a common point of the heart wall are superposed on the screen of the cathode ray tube by means of a coordinate transformation.