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AssigneeAtrium Medical Corporation
InventorsPaul Martakos, Theodore Karwoski, Steve A. Herweck
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A method of forming porous articles with a varying pore distribution by extrusion from a billet with a varying lubricant distribution. A single-polymer polytetrafluoroethylene is extruded and then stretched and sintered to provide a differential porous PTFE structure composed of fibers and nodes connected to one another by these fibers. The microfibrous structure has a portion within the cross-section that possesses a different pore size, accompanied by a different node and fiber geometry, than adjacent areas within that cross section. In a vascular graft, the pores taper inwardly, providing a fluid-tight lumen wall structure that prevents leakage, yet promotes cellular ingrowth and natural tissue regeneration. A node structure of radially-oriented plates provides flexibility, suture strength, and enhanced protection against collapse.
A method of producing a shaped porous article, such method comprising the stops of
A method of producing a prosthesis, such method comprising the steps of
In a method of manufacturing a porous PTFE article having a sintered microporous structure, the improvement comprising forming the article of a single PTFE material mixed with lubricant, wherein a lubricant concentration gradient is established through a cross-section of the article such that the lubricant has different levels at inside and outside, respectively of the article, and stretching the article to achieve a tapered pore structure extending from inside to outside of the article before sintering the article to fix its dimensions, the pore structure extending from smaller pores to larger pores, wherein larger pores are formed in regions where the article has higher levels of lubricant.
A method of producing a shaped porous article, such method comprising the steps
Dependencies are inferred from the claim text.