Near infra-red selective photothermolysis for ectatic vessels and method therefor

Abstract

Near-infrared selective photothermolysis for the treatment of ectatic blood vessels, for example, blood vessels of a portwine stain birthmark. This technique is especially applicable to deeper lying blood vessels in view of the better penetration of the near infrared light. Consequently, vessels are below a dermal/epidermal boundary can be reached. Near-infrared is defined as a range of approximately 700 to 1,200 nm. The optimal colors are near 760 or between 980 to 990 nm for most populations.

I claim:  
     
         1 . A method for performing selective photothermolysis, comprising: 
 generating near-infrared laser light; and    treating vascular targets with the laser light.    
     
     
         2 . A method as claimed in  claim 1 , further comprising treating ectatic blood vessels of vascular lesions with the laser light.  
     
     
         3 . A method as claimed in  claim 2 , further comprising treating ectatic blood vessels of a portwine stain birthmark.  
     
     
         4 . A method as claimed in  claim 1 , further comprising generating the laser light with a pulse duration of greater than 0.2 milliseconds.  
     
     
         5 . A method as claimed in  claim 1 , further comprising generating the laser light with a pulse duration within a range of 1 to 10 milliseconds.  
     
     
         6 . A method as claimed in  claim 1 , comprising irradiating the targets with laser light having a wavelength within a range of approximately 700 to 1,200 nm.  
     
     
         7 . A method as claimed in  claim 1 , wherein the laser light has a wavelength within a range of approximately 700 to 1000 nm.  
     
     
         8 . A method as claimed in  claim 1 , wherein the laser light has a wavelength within a range of approximately 720-790 nm.  
     
     
         9 . A method as claimed in  claim 1 , wherein the laser light has a wavelength within a range of approximately 750 to 780 nm.  
     
     
         10 . A method as claimed in  claim 1 , wherein the laser light has a wavelength of approximately 760 nm.  
     
     
         11 . A method as claimed in  claim 1 , further comprising generating the laser light with an alexandrite laser.  
     
     
         12 . A method as claimed in  claim 1 , further comprising generating the laser light with a titanium sapphire laser.  
     
     
         13 . A method as claimed in  claim 1 , further comprising generating the laser light with a chromium-doped fluoride laser.  
     
     
         14 . A method as claimed in  claim 1 , further comprising generating the laser light with a semiconductor diode laser.  
     
     
         15 . A method as claimed in  claim 1 , further comprising transmitting the laser light to the vascular target of a patient with an optical fiber delivery.  
     
     
         16 . A method as claimed in  claim 1 , further comprising time multiplexing the output of at least one laser to generate the laser pulse.  
     
     
         17 . A near-infrared selective photothermolysis device for treatment of vascular lesions, the device comprising: 
 a laser system for generating near-infrared laser light pulses having durations greater than 0.2 milliseconds; and    a delivery system for transmitting the laser light pulses to vascular targets of a patient.    
     
     
         18 . A device as claimed in  claim 17 , wherein the vascular targets are ectatic blood vessels of a portwine stain birthmark.  
     
     
         19 . A device as claimed in  claim 17 , wherein the laser light pulses have a wavelength in a range of approximately 700 to 1,200 nm.  
     
     
         20 . A device as claimed in  claim 17 , wherein the laser light pulses have a wavelength in a range of approximately 700 to 1000 nm.  
     
     
         21 . A device as claimed in  claim 17 , wherein the laser light pulses have a wavelength in a range of approximately 750 to 780 nm.  
     
     
         22 . A device as claimed in  claim 17 , wherein the laser light pulses have a wavelength of approximately 760 nm.  
     
     
         23 . A device as claimed in  claim 17 , wherein the laser light pulses have a wavelength in a range of approximately 800 to 1200 nm.  
     
     
         24 . A device as claimed in  claim 17 , wherein the laser light pulses have a wavelength in a range of approximately 720-950 nm.  
     
     
         25 . A device as claimed in  claim 17 , wherein the laser system comprises an Alexandrite laser.  
     
     
         26 . A device as claimed in  claim 17 , wherein the laser system comprises a titanium sapphire laser.  
     
     
         27 . A device as claimed in  claim 17 , wherein the laser system comprises a chromium doped fluoride laser.  
     
     
         28 . A device as claimed in  claim 17 , wherein the laser system comprises a semi-conductor diode laser.  
     
     
         29 . A device as claimed in  claim 17 , wherein the laser system multiplexes pulses from at least one laser to generate a longer effective pulse duration.  
     
     
         30 . A device as claimed in  claim 17 , wherein the delivery system comprises an optical fiber for combining and delivering light from at least one laser.  
     
     
         31 . A device as claimed in  claim 17 , wherein an effective pulse duration of the light pulse is between 1 and 10 msec.  
     
     
         32 . A method for treating a vascular lesion, the method comprising: 
 irradiating the lesion with near-infrared laser light pulses; and    controlling a duration of the pulses to approximately match a thermal relaxation time of blood vessels of the targets.    
     
     
         33 . A method as claimed in  claim 32 , further comprising generating the laser light pulses at a wavelength in a range of approximately 720 to 790 nm.