Methods and systems for removing hair using focused acoustic energy

Abstract

Hair is permanently removed from a patient's skin by transcutaneously focusing high intensity acoustic energy at a hair follicle. Usually, a region of a patient's skin is first ultrasonically imaged to locate individual hair follicles. The imaged hair follicles are then treated using a system which automatically directs the high intensity acoustic energy at the follicles.

1 . A method for removing hair from a patient's skin, said method comprising: 
 transcutaneously focusing high intensity acoustic energy at hair follicles beneath the skin.    
   
   
       2 . A method as in  claim 1 , wherein the acoustic energy is focused at predetermined follicle locations.  
   
   
       3 . A method as in  claim 2 , wherein said follicle locations are determined by acoustic imaging.  
   
   
       4 . A method for removing hair from a patient's skin, said method comprising: 
 scanning an acoustic transducer over the skin surface to identify locations of the hair follicles beneath the skin; and    transcutaneously focusing high intensity acoustic energy at at least some of the identified follicle locations.    
   
   
       5 . A method as in  claim 4 , wherein the high intensity acoustic energy is transcutaneously focused from an acoustic transducer.  
   
   
       6 . A method as in  claim 5 , wherein a single acoustic transducer is used both to scan for the hair follicle locations and to deliver the focused high intensity acoustic energy.  
   
   
       7 . A method as in  claim 5 , wherein different acoustic transducers are used for scanning for the hair follicle locations and for delivering the focused high intensity acoustic energy.  
   
   
       8 . A method for removing hair from a patient's skin, said method comprising: 
 immobilizing a transducer platform over a target area of the patient's skin;    scanning an acoustic transducer over the skin to determine the locations beneath the skin of hair follicles relative to the mobilized transducer platform;    positioning an acoustic transducer over the skin at at least some of the determined locations relative to the immobilized platform; and    transcutaneously focusing high intensity acoustic energy at hair follicles from the positioned acoustic transducer.    
   
   
       9 . A method as in  claim 8  wherein scanning comprises mechanically advancing the transducer in X- and Y-directions over an imaging plane to known coordinates.  
   
   
       10 . A method as in  claim 9 , wherein positioning comprises mechanically advancing the transducer in X- and Y-directions to the same coordinates.  
   
   
       11 . A method as in  claim 1 ,  4 , or  8 , wherein transcutaneously focusing comprises adjusting the depth of focus.  
   
   
       12 . A method as in  claim 11 , wherein adjusting the depth of focus comprises translating a transducer along a vertical line.  
   
   
       13 . A method as in  claim 11 , wherein adjusting the depth of focus comprises adjusting the curvature of a transducer surface.  
   
   
       14 . A method as in  claim 11 , wherein adjusting the depth of focus comprises controlling the operation of a phased array transducer.  
   
   
       15 . A method as in  claim 1 ,  4 , or  8 , wherein the high intensity acoustic energy is focused at a depth beneath the skin in the range from 1 mm to 6 mm and at a width in the range from 0.1 mm to 0.3 mm.  
   
   
       16 . A method as in  claim 15 , wherein the high intensity acoustic energy is delivered under conditions selected to raise the temperature at the hair follicle to at least 50° C. for a time of at least 0.1 sec.  
   
   
       17 . A method as in  claim 16 , wherein the ablative energy is delivered in an amount from 0.1 J to 10 J to each hair follicle.  
   
   
       18 . A method as in claims  4  or  8 , further comprising producing an image of the scanned hair follicle locations.  
   
   
       19 . A method as in  claim 18 , further comprising designating which of the hair follicles for which locations have been scanned and to be ablated.  
   
   
       20 . A system for hair removal, said system comprising: 
 a transducer selectively operable to image hair follicle locations and to acoustically ablate hair follicles at said imaged locations;    means for tracking the location of the transducer over a patient's skin surface; and    a controller for acquiring image data from the transducer and directing high intensity acoustic energy to selected ones of the imaged hair follicles.    
   
   
       21 . A system as in  claim 20 , wherein the tracking means comprises: 
 a transducer platform adapted to be engaged against the patient's skin; and    a drive system for advancing the transducer over a planar region defined by the platform, wherein the position of the transducer can be both selected and recorded.    
   
   
       22 . A system as in  claim 21 , wherein the drive system is a X-Y motion positioner.  
   
   
       23 . A system as in  claim 22 , wherein the X-Y motion positioner is repeatable to ±0.01 mm.  
   
   
       24 . A system as in  claim 1 ,  4 , or  8 , wherein the high intensity acoustic energy is focused at a depth beneath the skin in the range from 1 mm to 6 mm and at a width in the range from 0.1 mm to 0.3 mm.  
   
   
       25 . A system as in  claim 24 , wherein the high intensity acoustic energy is delivered under conditions selected to raise the temperature at the hair follicle to at least 50° C. for a time of at least 0.1 sec.  
   
   
       26 . A system as in  claim 24 , wherein the ablative energy is delivered in an amount from 0.1 J to 10 J to each hair follicle.  
   
   
       27 . A system as in  claim 20 , further comprising a display which provides a visual depiction of the hair follicle locations.  
   
   
       28 . A system as in  claim 27 , further comprising means for a user to designate which of the hair follicles in the visual depiction are to be ablated.