Uniform illuminator for phototherapy

• US 5,698,866 A
• Filed: 05/28/1996
• Issued: 12/16/1997
• Est. Priority Date: 09/19/1994
• Status: Expired due to Fees

• Current Assignee: PDT Systems Incorporated
• Original Assignee: PDT Systems Incorporated
• Inventors: Graham, Gregory S., Dunn, John Brian, Dalton, Brian K., Doiron, Daniel R., Lytle, A. Charles
• Primary Examiner(s): Saadat, Mahshid D.
• Assistant Examiner(s): CLARK, JASMINE JHIHAN B
• Application Number:
  US08/654,059
• Time in Patent Office: 567 Days
• Field of Search: 257/98, 257/91, 257/99, 257/88, 257/432, 257/95, 257/717, 250/504 H, 250/504 R, 361/676, 361/688
• US Class Current: 257/99
• CPC Class Codes: A61B 2017/00057 Light
• CPC Class Codes: A61B 2090/0436 Shielding
• CPC Class Codes: A61B 2090/049 against light, e.g. laser
• CPC Class Codes: A61N 2005/005 for cooling the radiator
• CPC Class Codes: A61N 2005/0644 Handheld applicators
• CPC Class Codes: A61N 2005/0652 Arrays of diodes
• CPC Class Codes: A61N 5/062 Photodynamic therapy, i.e. excitation of an agent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/3025 Electromagnetic shielding

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.

Claims

1. A light delivery device for delivering phototherapeutic light to uniformly illuminate a surface of a tissue, said device comprising:

(a) a semiconductor light source producing therapeutic light; and

(b) a handpiece adapted to be electrically connected to a source of electrical power, said semiconductor light source having means adapted for releasably attaching said semiconductor light source to said handpiece, said semiconductor light source further comprising, in combination;

(i) a support comprising a sheet of electrically and thermally conductive material and having a planar upper surface;

(ii) a plurality of light emitting diodes disposed in two-dimensional array upon a said planar surface of said support, each of said light emitting diodes having a first electrical connector electrical connected to said support and a second electrical connector;

(iii) a cooling means in thermal connection with said support adapted to remove heat from said support;

(iv) a cathode comprising a single sheet of electrically conductive material having a top surface and a bottom surface and a plurality of perforations therebetween, said bottom surface of said single sheet being affixed to said planar surface of said support by an electrically non-conductive adhesive, said perforations disposed on said single sheet to form a second two-dimensional ray thereon, said perforations having a large circular opening at said top surface and a small circular opening on said bottom surface of said single sheet and an inner surface therebetween and wherein each of said small circular openings circumscribe one of said light emitting diodes, and wherein the center of said small circular opening of each perforation of said plurality of parabolic perforations overlies the center of a circumscribed light emitting diode comprising said light emitting diode array.

2. The light delivery device of claim 1 wherein said inner surface of said parabolic perforations comprise a reflective material.

3. The light delivery device of claim 1 wherein said first electrical connector is in electrical communication with said support and wherein said second electrical connector is in electrical communication with said cathode.

4. The light delivery device in accordance with claim 1 further comprising a source of electrical power having an anodic output and a cathodic output wherein the anodic output is in electrical communication with said support and wherein said cathodic is in electrical communication with said cathode.

5. The light delivery device in accordance with claim 1 further comprising a reflector affixed to said upper surface of said single sheet, said reflector comprising a sheet a plurality of parabolic perforations therein, each of said parabolic perforations presenting a circular opening circumscribing and centered upon of the light emitting diodes comprising the light delivery device.

6. The light delivery device in accordance with claim 2 wherein said second electrical connector is in electrical communication with said cathode.