Latticework

Abstract: A bifurcated stent graft implantable in branched internal passageways includes an open-frame stent latticework formed of helically wound structural strands, and a graft sleeve formed of interwoven textile strands. The sleeve is substantially impervious to fluids and is adjustable along with the graft between a nominal state and radially-reduced axially-elongated state, according to substantially the same relationship of radial reduction versus axial elongation. The sleeve and stent are bonded to one another at least at proximal and distal end regions of the stent graft. The sleeve preferably is surrounded by the stent, and incorporates a flow dividing feature in the form of an axially extending seam. The seam brings together portions of the sleeve that otherwise would be circumferentially spaced apart in the tubular sleeve shape. The stent latticework and graft sleeve can be coextensive, the sleeve can extend distally beyond the latticework, or the latticework can extend proximally beyond the sleeve, depending on the intended use. In other alternative embodiments, the sleeve can surround the latticework.

Abstract: A stent graft for transluminal implantation includes a resilient tubular interbraided latticework of metal or polymeric monofilaments, a tubular interbraided sleeve of polymeric multifilament yarns, and an adhesive layer between the sleeve and latticework for bonding them together. The monofilaments and multifilament yarns are arranged in respective sets of axially spaced apart and oppositely directed helices, concentric on a common axis of the stent graft. The respective braid angles of the monofilaments and multifilament yarns are carefully matched to ensure that the latticework and sleeve behave according to substantially the same relationship governing the amount of radial reduction that accompanies a given axial elongation. According to a process for fabricating the stent graft, the latticework and sleeve are braided and thermally set independently, then bonded to one another by a silicone polymer adhesive applied evenly to the latticework in a liquid spray that also incorporates an organic solvent. Especially preferred yarns are composed of essentially untwisted filaments that define non-circular yarn cross sections. Alternative stent graft constructions feature exterior and interior sleeves on opposite sides of the latticework, two or more sleeves axially spaced from one another on the same latticework, a latticework formed of a recovery metal, and a plastically deformable latticework.

Abstract: Thermoplastic suspensions of 55 vol.% zirconia in a wax-based vehicle were extruded through a range of fine nozzles with diameters from 76 to 510 μm. Fixed pressure extrusion under a maximum nitrogen gas pressure of 350 kPa and an extrusion temperature of 175 °C were used. The ability of unfiltered suspensions to flow in fine nozzles depended critically on the mixing method. Ceramic latticework in the form of structures suitable for bone substitute scaffolds were created by extrusion freeforming, a process also known as fused deposition modelling (FDM) or fused deposition of ceramics (FDC). However, precisely ordered deposition could not be obtained by fixed pressure extrusion with a 55 vol.% suspension because of rate variations due to slight mixing inhomogeneities. The quality of welds was examined. Heat transfer considerations show that the use of thermoplastic suspensions is not ideal for fine (

Abstract: A polymer building or other structured wall form construction wherein forms prefabricated of polymer, such as polystyrene, are assembled together, spaced apart by integrally connecting polymer or blocks, spacers, or spool means, erected upon a foundation footing, or other base structure, through their insertion of L-shaped ties, with the wall forms being erected to the height desired for the subject building or other structure, whether it be a commercial, industrial, or residential building, through the application of tee-shaped ties therebetween, Reinforcement is located in the spacing between the blocks or spacers, of the wall forms, and concrete may be poured therein, either at the job site, where the building is being constructed, or at the manufacturing plant, where the wall forms are formed, in order to provide a latticework of reinforced concrete for the composite wall. The internal surface of each of the inner and outer liners forming the wall form are shaped, into the configuration of an I-beam, in order that any concrete poured therein will undertake the cross-sectional configuration of an I-beam, to add further reinforcement to the fabricated building, once a wall is completed. A top beam form of plate cap is arranged upon the upper edge of the formed wall, with the concrete being poured simultaneously with the construction of the assembled wall. Bracing held together by ties and locked into position by fasteners secure the wall forms together, in their erected disposition, in preparation for the pouring of the latticework of concrete reinforced composite wall.