Method and apparatus for improving safety during exposure to a monochromatic light source

Abstract

A method and apparatus are disclosed for improving bodily safety during exposure to a monochromatic light source by diverging the monochromatic light, such as with a highly durable diffuser. At a first position of the distal end of the monochromatic light source the energy density of an exit beam from said distal end is substantially equal to the energy density of the monochromatic light required for desired applications and at a second position of the distal end the energy density of the light emitted therefrom is significantly less than the energy density of the monochromatic light. Accordingly, a laser unit suitable for aesthetic treatment, medical treatment or industrial treatment is converted into an eye safe laser unit. Eye safety is further enhanced by measuring the radiance of the divergent monochromatic light and issuing a warning as a result of a mishap if the radiance of the divergent monochromatic light is greater than a predetermined safe value, and if desired, generating a visible flash prior to the emission of a pulse of monochromatic light to induce an eye of a bystander to blink or to change its field of view in order to avoid staring at the monochromatic light.

1 . Handpiece, comprising: 
 a) a handpiece body for transmitting intense pulsed light through a distal end of said body to a skin target;    b) light delivery means for delivering said light from a light source to said distal end;    c) a U-shaped evacuation chamber connected to, or integral with, said body, the proximal end of said evacuation chamber being provided with a clear transmitting element which is transparent to said light, air or condensed vapors being evacuated from said evacuation chamber upon application of a sufficient vacuum therein;    d) means for positioning said transmitting element to be substantially parallel to said skin target and at a distance separated from skin adjoining the skin target ranging from 0.5 to 30 mm and for positioning a wall of said evacuation chamber to be substantially in contact with said skin target;    e) means for directing the light which is transmitted through said transmitting element and said distal end to said skin target via said evacuation chamber; and    f) means for controlling pulse duration in accordance with the color of the target or skin type of a patient,    wherein the energy density of said light ranges from 1 to 70 J/cm2, the wavelength of said light ranges from 400 to 1800 nm, and the pulse duration ranges from 10 nanoseconds to 900 msec.    
     
     
         2 . The handpiece according to  claim 1 , wherein the light source is suitable for emitting light that is absorbed by tissue at a predetermined penetration depth below an outer skin surface.  
     
     
         3 . The handpiece according to  claim 2 , wherein the energy density level of the light is adjustable to a level which is sufficient for the spectral absorption of the skin target.  
     
     
         4 . The handpiece according to  claim 3 , wherein the energy density level of the light is adjustable to a level which is sufficient for the temporal spectral absorption of the skin target attained in response to the vacuum level applied to the evacuation chamber.  
     
     
         5 . The handpiece according to  claim 1 , wherein the skin target is selected from the group of unwanted hairs, unwanted vascular lesions, collagen to be shrunk or remodeled, and unwanted bactreria located under the skin surface.