Surface-treated stent, catheter, cannula, and the like

An echogenic medical device insertable into a medium and imageable with sonic imaging equipment, comprising:

• a member for insertion into a medium having a first acoustic impedance, said member including a base material from a group consisting of polyurethane, polyethylene, nylon, C-FLEX.TM., polytetrafluoroethylene, polyvinyl chloride, polypropylene, polyester, and silicone and an interface layer deposited on said base material, said base material having an outer surface having a surface energy in a range of 20 to 30 dynes per centimeter, said interface layer deposited on said outer surface forming a deposition surface and having a discrete, particulate-type, discontinuous curved surface having a diameter less than a wavelength of a sonic beam from said imaging equipment, said member including a particulate in said deposition surface for forming said particulate-type, discontinuous surface in said deposition surface, said particulate including a plurality of particles from a group of tungsten and glass materials in a generally spherical shape, said interface layer including a metal from a group consisting of titanium, tungsten, barium, bismuth, silver, gold, platinum, and palladium different from said base material and having a second acoustic impedance different from said first acoustic impedance of said medium, said first and second acoustic impedances having at least a predetermined difference therebetween, said metal of said interface layer having been vacuum deposited on said deposition surface of said base material using ion beam assistance, whereby said difference between said first and second acoustic impedances and said curved surface responds to said sonic beam to produce an image of said member.