| 摘要 |
PURPOSE: A medical implant, tubing and method to provide enhanced X-ray detection intensity in catheters, stents, vascular grafts or other tubular implants. In one aspect the medical implant includes a visually transparent radiopaque polymer and a filler material having a radiopaque component. CONSTITUTION: Figure 4 shows an embodiment resulting from co-extrusion of the visually transparent radiopaque polymer having no filler material and the filler material (filled polymer). In Figure 4, the filler material (filled polymer) is largely isolated and concentrated in one or more segments(40) disposed within the otherwise visually clear tubing of, for example, brominated polymer(10). When the tubing is viewed lengthwise, the segments(40) of filler material tend to form one or more stripes of varying size which extend generally longitudinally along some extent of the tubing, basically parallel to the flow direction within the lumen(30). This embodiment allows the specific placement of radiopaque, yet potentially optically obstructing segments (filled polymer) so as to allow observation of fluid flow while retaining the superior radiopacity of the segments, appearing as stripes within the tubing, wherein concentrated amounts of filler material are disposed. As with the embodiment of Figure 3, a co-extrusion using two extruders with split extrusions may form the striped pattern. |
