摘要:
A prosthesis for an inadequate or diseased heart valve, the prosthesis being formed of a porous fabric comprising multifilament synthetic yarns supported on a plural-lobed frame. The frame has generally parallel legs each comprising a pair of rod portions. The fabric is inserted between the rod portions of the legs to form flexible leaflets. Each leaflet consists essentially of a textile of filaments having a substantial number of open interstitial spaces in the range of 20 to 40 microns evenly distributed throughout the fabric. The resulting composite structures are free of thrombogenic complications.
摘要:
A frame system for heart valve prosthesis. A first frame has at least three generally parallel legs each comprising a pair of rod portions connected at one end and diverging at the other end as lobes respectively connecting with rod portions of others of said legs. The lobes form an aperture therebetween and the legs are adapted to receive the margin of a valve leaflet between the rod portions thereof. Thus, the leaflet may be secured to two adjacent legs and the interconnecting lobe so as to have a free edge extending between said adjacent legs. A second frame is adapted to nest with the first frame and comprises a rod formed to be substantially congruent with the interconnecting lobes, whereby the leaflets may be secured to and between the frames.
摘要:
Sheet materials for cardiovascular and other prosthetic implants are fabricated of synthetic elastomers. These materials are characterized by molecular configurations that produce a nonlinear tensile modulus characteristic similar in shape to that of natural tissue. Selected elastomers, when formed as sheet material of appropriate geometrical configuration, promote the formation of natural tissue thereon which is appropriate for the mechanical characteristics desired.
摘要:
Prostheses for inadequate or diseased heart valves and blood vessels, formed of fabrics comprising multifilament synthetic yarns. For a heart valve the fabric is supported on a three-lobed frame. During manufacture, the fabric is subjected to a plural step compressive shrinking and crimping process to impart nonisotropic elastic compliance approximating the natural mechanical properties. The resulting composite structures are free of thrombogenic complications.
摘要:
An artificial ligament device is provided for joining the ends of two bones wherein at least one of the bones has a tunnel extending therethrough. The device comprises a multilayered or tubular woven ligament having an intra-articular region, at least one bend region, and at least one end region, each region being woven so as to possess qualities of flexibility and strength suitable to the particular types of stresses it receives during use. The end region and a portion of the bend region are encased within a polymer bone block, usually by thermomolding, and the bone block is inserted into the bone tunnel to attach the ligament. The bone block is molded to provide a fixed bend radius for the ligament at the point of exit therefrom so as to control the amount of bending stress on the ligament during flexure and extension of the joint.
摘要:
A thermal insulator is disclosed which comprises fibrillated staple fibers exemplified by fibrillated fibers of poly (p-phenylene terephthalamide). The fibers are fibrillated on a carding machine equipped with metallic clothing.
摘要:
The invention concerns a braid structure comprising a plurality of braided layers of stranded material in which the layers are laid down in a single pass of a braiding machine, with at least one strand of each layer extending into a contiguous layer to form an interlock between the layers. The invention also concerns a machine and a method of making the structure by supplying groups of strands, (R, B, G, O, W), to a braid forming station, whereby each group of strands forms a braid layer. A strand (R) from one of the groups passes into or through the strands (B) of a group of an adjacent layer to form an interlock therebetween.
摘要:
A rigidized fiber filter element is produced from a precursor fiber web. The precursor fiber web contains heat-shrinkable fibers or binder fibers or both. The web is exposed to temperatures sufficiently elevated to cause shrinkage of the fibers or melting of the binder. After cooling the web, the filter elements produced are self-supporting, and may have densities up to 500 kg/m.sup.3 to improve filtration while retaining good functional characteristics for operating pressure drop and air permeability. Rigidized fiber filter elements can be constructed of one material, and thus may be suitable for recycling.
摘要翻译:刚性纤维过滤元件由前体纤维网制成。 前体纤维网包含热收缩纤维或粘合剂纤维或两者。 将幅材暴露于足够升高的温度以引起纤维收缩或粘合剂熔化。 冷却网后,所生产的过滤元件是自支撑的,并且可以具有高达500kg / m 3的密度以改善过滤,同时保持操作压降和透气性的良好功能特征。 刚性纤维过滤元件可由一种材料构成,因此可适用于回收。
摘要:
Insulating material comprising continuous filaments of a synthetic material characterized in that the filaments have a mean diameter of from 4 to 20 microns and in that the filaments have been separated by a stretching and subsequent relaxation of a crimped tow of said filaments.
摘要:
A rod assembly comprising a core component and a sheath component and having an elongate cross-section, the sheath component consisting of an anisotropic assembly of non-metallic filamentary elements embedded in a polymeric matrix whereby the bending stiffness for deformations about an axis parallel to the major axis of the rod assembly is less than the bending stiffness of the same core and sheath components in a radially symmetrical configuration, and in which the core and sheath components have load-elongation characteristics so that the ratio of the strain to the strain-to-break in the sheath is essentially equal to the ratio of the strain to the strain-to-break in the core throughout the working load range.