Apparatus for relieving the symptoms of deep vein thrombosis comprises a fabric envelope having on one surface a plurality of projections and on an opposed surface, one or more strips of a hook and loop-type fastener sold under the trademark Velcro\xae or similar material for releasably attaching the envelope to a carpeted floor surface. A filtered sheet is displayed to the user, where the filtered sheet is obtained by applying the first filter to the unfiltered sheet. Highly efficacious drug candidates are identified by screening the libraries for binding and inhibitory activity against both HIV and FIV protease. The base layer, plurality of circuit traces and insulative layer can form a flexible circuit sheet.