US Patent 7814943 Apparatus and method for dispensing foam

Apparatus for dispensing foam for the treatment of, inter alia, varicose veins. The apparatus includes a source of foam and a dispensing device which has an inlet in communication with the source of foam, a usable foam outlet, and a waste bleed outlet. The waste bleed outlet communicates with the inlet and with the useable foam outlet, and has a higher resistance to flow of foam than that of the usable foam outlet. The useable foam outlet may be blocked off such that foam may flow through the high resistance waste bleed outlet, and the usable foam outlet may be opened such that foam may flow through the usable foam outlet.