| 摘要 |
A multilayer high strength balloon for a dilatation catheter is provided. The balloon comprises a plurality of balloon layers, including an inner layer which has a cylindrical midportion, a cone at each end, and necks at the ends of the cones, and at least one additional layer which has the cylindrical midportion and cones. Each layer is formed from a polymeric material, and perhaps an inelastic, biaxially oriented, thermoplastic material. Preferably, one or more of the balloon layers is blow molded and stretched to biaxially orient the material to form a very high strength layer. The layers have differing lengths along the catheter to which the multilayer balloon is coupled. The multilayer balloon resulting from the plurality of balloon layers, of which one or more has been biaxially oriented, is stronger than a single layer balloon of the same finished diameter which has been made from the same material with comparable thickness. The composite high strength balloon may be formed to eliminate undesirable thickening of the cone regions of conventional blow molded balloon designs by stepping the cone regions so that they are not substantially greater than the wall thickness in the midportion of the balloon. The resulting balloon is better adapted to collapse to a low profile about the catheter shaft on which it is mounted.
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