| abstract |
A body implantable electrode (20,68) includes a platinum wire or filament (28,40,46,52,70) compressed and bundled into a serpentine configuration and retained within a platinum screen (30), thus to form a highly porous electrode. The electrode body is then surface treated by vapor deposition or vapor deposition in combination with electroplating, to provide an adhesion layer (38,48,54), a texturizing layer (38,50,56), and one or more catalytic cover layers (44,58,60). The texturizing layer, which can be titanium, carbon black or aluminum, is formed with multiple nodules and depressions which substantially increase the reactive surface area of the electrode. The catalytic layer can be platinum, platinum-black or platinum followed by a layer of carbon. The combination of macro porosity and micro texture provides an electrode that promotes tissue ingrowth after implant and maintains a low chronic stimulation threshold due to its large reactive surface area in proportion to its geometric size. |