Uniform illuminator for phototherapy

Abstract

A light delivery device including an interchangeable handpiece and a semiconductor light source module adapted to releasably attach to the handpiece. The light source module includes a two-dimensional array of light emitting diodes (LED's) disposed on a surface of a fluid-cooled electrically conductive support plate. The device is adapted for uniformly illuminating a tissue surface with phototherapeutic light. The phototherapeutic light is produced by an array of over-driven LED's mounted on the surface of the heat-sinked support. The semiconductor light source employs a multi-layer construction wherein electrically conductive layers are thermally isolated from each other. The device is rugged, inexpensive and can produce high optical power while operating at a temperature well below the temperature at which device failure occurs. The light source module is adapted to be releasably connected to an interchangeable LED handpiece which provides power to the LED's and conducts a coolant fluid. The light source includes an integral unitary reflector for directing the light output from the individual LED's in the LED array in a desired direction. The reflector is a thin perforated sheet having a top, tissue facing surface and bottom surface and an array of cup shaped openings therebetween, each such perforation in the sheet being disposed to overly a LED in the LED array. The inner surface of each cup-shaped opening has a parabolic vertical cross section and is reflectively coated to maximize red reflectivity.