Abstract:
Described herein are methods and apparatus for treating fungal nail infections and similar diseases with light therapy. In one embodiment, an apparatus that utilizes one or more blue light emitting diodes (LED) to irradiate fungus residing under and around the nail is applied externally to a toe or finger in order to kill the fungus and restore normal nail growth. Light therapy may applied in this manner periodically at scheduled times. Another embodiment involves the use of a bootie-like structure having blue light emitting diodes for irradiating the toes, heal, and foot bottom.

Description:
CLAIM OF PRIORITY  
       [0001]     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 60/824,381, filed Sep. 1, 2006, the entire disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     This invention pertains to methods and devices for treating cutaneous disease.  
       BACKGROUND  
       [0003]     Fungal infection, especially of the toes and feet is a common problem. One such fungus, tinea pedis, causes athelete&#39;s foot. Fungal infections may also occur in the nail bed, matrix, or nail plate of fingers and toes. The medical terms for this type of fungal infection are onychomycosis or tinea unguium. Fungal infections of the nail are due to many factors and may affect a significant portion of the population in developed countries. The most common type of fungal nail infection involves the end of the nail when the fungi invade the hyponychium. Initially, the nail plate splits from the nail bed, a process called onycholysis. The end of the nail then turns yellow or white, and keratin debris develops under the nail causing further separation. The fungus grows in the substance of the nail, causing it to become fragile and crumble. The fungal organism responsible for most fungal nail infections is trichophyton rubrum.  
         [0004]     Once the fungus establishes itself under a toenail or fingernail, it is difficult to cure. Topical preparations are not usually effective in treating fungal nail infections. The only generally effective approach involves oral medications that enter the nail from the blood. All of these medications have significant side effects and interact with many other medications. Anyone taking oral antifungal medications must have periodic tests done to monitor liver and blood cell function. The medications are also expensive and must be taken for several months.  
       SUMMARY  
       [0005]     Described herein are methods and apparatus for treating fungal nail infections and similar diseases with light therapy. In one embodiment, an apparatus that utilizes one or more blue light emitting diodes (LED) to irradiate fungus residing under and around the nail is applied externally to a toe or finger in order to kill the fungus and restore normal nail growth. Light therapy may be applied in this manner periodically at scheduled times. Another embodiment involves the use of a bootie-like structure having blue light emitting diodes for irradiating the toes, heal, and foot bottom. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIGS. 1 through 3  illustrate different embodiments of apparatus for delivery cutaneous light therapy. 
     
    
     DETAILED DESCRIPTION  
       [0007]     Research has demonstrated the effectiveness of blue light at approximately 470 m wavelength in causing retarded growth and cell death. Such effects have been found to occur with light exposure time periods of between 8 and 72 hours. Described herein are apparatus having one or more blue light LEDs that are adapted to kill fungus residing on the body on such areas as the fingers, toes and feet. The blue light LEDs may be designed to emit light at a wavelength of 470 nm or within a range of 400 to 500 nm and with an intensity of 7500 mcd or within a range of 1000 to 10000 mcd.  
         [0008]     One embodiment includes a clip designed to fit over toe or finger in a manner similar to clips worn on the finger for use in pulse oximetry. The clip in this embodiment is a toe or finger clip that includes two hinging portions with a spring to keep the clip closed around the toe or finger. The clip may contain one or more blue light LEDs mounted in the clip light is emitted into the nail when the clip is worn. The apparatus may include a battery, an on/off switch, and control circuitry for controlling the operation of the LEDs, all or part of which may be incorporated into the clip or be located externally.  
         [0009]     Another embodiment includes a bootie that may be worn on the foot while sitting or laying down such as during sleep. The bootie may contain an array of blue LEDs across the front, back and bottom facing towards the inserted foot. The bootie may also incorporate a clear foam-like padding between the LEDs and foot for providing comfort. The apparatus may include a battery, an on/off switch, and control circuitry for controlling the operation of the LEDs, all or part of which may be incorporated into the bootie or be located externally. In one embodiment, power for the LEDs within the bootie is provided by batteries housed on a cuff worn around the ankle above the foot needing treatment, and a wire cable connects the cuff to the bootie. The cuff in this embodiment may also have an on/off switch.  
         [0010]     Other embodiments include a disposable clip or substrate containing blue LEDs that can be fixed to the area needing treatment, where fixation may be performed with an adhesive. Power, switch and control circuitry in this embodiment may be provided by a separate module worn by the person on the ankle or wrist.  
         [0011]     In any of the apparatus for delivering light therapy as described herein, a timer may be incorporated into the control circuitry of the apparatus to limit the light exposure time. The timer may be controlled by a user interface that allows a patient to manually set the time for which light is to be delivered. A predetermined exposure time, such as eight hours, may be programmed in the timer. In certain cases, only one eight hour treatment may be necessary. Time is then allowed for new nail material to grow and the old nail with deceased fungus to be removed.  
         [0012]      FIG. 1  depicts one embodiment of an apparatus for delivering cutaneous light therapy to a toenail or fingernail. A clip  100  comprises a lower portion  101  and an upper portion  102  that are opposed to one another and each pivotally attached to a spring  103 . The two portions may be pivoted apart around the spring in order to open the clip, while the spring acts to hinge the two portions together and close the clip around a toe or finger. The upper portion of the clip incorporates one or more blue LEDs  104  disposed so as to emit light toward the nail when the clip is closed around a toe or finger. A foam padding  105  may be fitted over the inner surfaces of the upper and lower clip portions for patient comfort. Mounted within a body portion  106  of the clip are control circuitry  107  and a battery  108  which connect to the LEDs by wires  109 . The control circuitry controls operation of the LEDs by gating power from the battery. Interfaced to the control circuitry is an on-off switch  110  that may be actuated by the patient. Timing circuitry may also be incorporated into the control circuitry to allow therapy to be delivered for predetermined periods. A timer switch  111  may be provided to allow the patient to set a specified duration for the therapy.  
         [0013]      FIG. 2  shows another embodiment of an apparatus for delivering cutaneous light therapy that includes a bootie  200 . This embodiment may be used to treat not only nail infections but other cutaneous infections as well such as athlete&#39;s foot. The bootie  200  is a contoured structure into which may be fitted a patient&#39;s foot. The bootie  200  incorporates one or more blue LEDs  201  disposed on its inner surface so as to radiate toward the patient&#39;s skin. A liner  202  made of clear foam material may be interposed between the LEDs and the patient&#39;s skin to enhance patient comfort while still allowing light transmission. The apparatus also includes a cuff  206  that may be worn around the patient&#39;s arm or ankle. Mounted within the cuff  206  are control circuitry  207  and a battery  208  which connect to the LEDs by wires  209 . The control circuitry controls operation of the LEDs by gating power from the battery. Interfaced to the control circuitry is an on-off switch  210  that may be actuated by the patient. Timing circuitry may also be incorporated into the control circuitry to allow therapy to be delivered for predetermined periods. A timer switch  211  may be provided to allow the patient to set a specified duration for the therapy.  
         [0014]      FIG. 3  shows another embodiment that includes a substrate  300  that incorporates one or more blue LEDs  301 . The substrate  300  includes a midportion  302  for containing the LEDs  301  which are disposed so as to radiate toward the patient&#39;s skin. The substrate  300  also includes peripheral portions  303  which are adapted for fixation to the patient&#39;s skin such as by an adhesive or by being wrapped around an extremity and then mechanically connected together (e.g., by a hook and loop fastener). In one embodiment, the LEDs are connected to an external control device such as the cuff  206  described above which contains the battery and control circuitry. In another embodiment, the midportion  302  has a compartment for containing the LEDs and battery  304 . The apparatus may be constructed so that the LEDs are activated when inserted into the midportion with the battery. In this embodiment, the substrate may be made disposable after removal of the battery and LEDs.  
         [0015]     Although the invention has been described in conjunction with the foregoing specific embodiment, many alternatives, variations, and modifications will be apparent to those of ordinary skill in the art. Such alternatives, variations, and modifications are intended to fall within the scope of the following appended claims.