Abstract:
A hand held laser for treating a skin condition includes a housing comprising a first end, a second end and a cavity therein wherein the cavity includes a substantially light reflective surface and wherein the housing comprises at least one fin extending from an exterior surface of the housing. The laser includes a flash lamp having a first axis and being retained within the cavity in a first selected position and a laser rod having a second axis and being retained within the cavity in a second selected position and wherein the first axis and the second axis are substantially parallel to each other, wherein as the flash lamp is pumped the laser rod produces a laser beam for treating the skin condition.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   The present application is based on and claims the benefit of U.S. provisional patent application Ser. No. 60/778,182, filed Mar. 1, 2006, the content of which is hereby incorporated by reference in its entirety. 

   FIELD OF THE INVENTION 
   The present invention relates to a laser for use in medical treatments. More particularly, the present invention relates to hand held laser for use in medical treatments. 
   BACKGROUND OF THE INVENTION 
   Lasers are being used more frequently in medical treatments to reduce blemishes on a patient&#39;s skin. Lasers are useful in removing port wine stains, scars and wrinkles from a patient&#39;s skin to improve the patient&#39;s appearance. Lasers are also useful in removing unwanted tattoos. 
   Many of the laser treatments require the laser to be mobile to treat the skin blemish. To accommodate the need to for the laser to be mobile, the size of the lasers are being reduced such that the laser can be housed in a hand held housing. However, the laser must supply enough energy to complete the selected procedure. The small size of the laser coupled with the energy delivery requirements has caused the lasers to have a tendency to heat up over time with use, and require the laser to be shut down to cool to a selected temperature. 
   Typically, water or another cooling fluid is utilized to remove the heat that is generated as the laser is utilized. However, because of the mobility and energy requirements of the laser, a circulating coolant may not remove a sufficient amount of heat to allow the laser to run continuously for an extended period of time without heating to excessive temperatures. 
   SUMMARY OF THE INVENTION 
   The present invention includes a hand held laser for treating a skin condition having a housing comprising a first end, a second end and a cavity therein wherein the cavity includes a substantially light reflective surface and wherein the housing comprises at least one fin extending from an exterior surface of the housing. The laser includes a flash lamp having a first axis and being retained within the cavity in a first selected position and a laser rod having a second axis and being retained within the cavity in a second selected position and wherein the first axis and the second axis are substantially parallel to each other, wherein as the flash lamp is pumped the laser rod produces a laser beam for treating the skin condition. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the hand-held laser of the present invention. 
       FIG. 2  is a sectional view of the hand-held laser of the present invention along section line  2 - 2  in  FIG. 1 . 
       FIG. 3  is a sectional view along section line  3 - 3  in  FIG. 1 . 
       FIG. 4  is a left side view of the main body of the laser of the present invention. 
       FIG. 5  is a left side view of the laser of the present invention. 
       FIG. 6  is a perspective view of a casing containing the laser of the present invention. 
   

   DETAILED DESCRIPTION 
   A hand-held laser of the present invention is generally illustrated in  FIG. 1  at  10 . The hand-held laser  10  includes a housing  12  with a plurality of fins  14  extending from an exterior surface  16  and about a perimeter of the housing  12 . The plurality of fins  14  increase the surface area of the external surface  16  of the housing  12  which increases the rate at which heat is transferred from the laser  10  to the atmosphere proximate the laser  10 . 
   The housing  12  typically includes seventeen uniformly spaced fins  14  extending around the perimeter of the housing  12 . However, a housing  12  with one or more fins  14  is contemplated that may or may not extend around the entire perimeter of the housing  12 . 
   The housing  12  is typically constructed from stainless steel. Stainless steel is a desirable material of construction due to its strength, durability, resistance to corrosion, ability to reflect light beams and high heat capacity. However, other materials of construction of the housing  12  are also contemplated including, but not limited to gold, silver and titanium. 
   The housing  12  is typically of a unitary construction. However a housing  12  with two or more components secured together are also contemplated. 
   Left and right end caps  26 ,  28  are attached to the left and right ends  18 ,  20 , respectively, of the housing  12 . The left and right end caps  26 ,  28  are typically attached to the left and right ends  18 ,  20  of the housing  12  with threaded engagements of bolts  25  with threaded bores  27  proximate the corners of the left and right end caps  26 ,  28  as illustrated in  FIGS. 4 and 5 . The engagements of the left and right end caps  26 ,  28  with the left and right ends  18 ,  20  of the housing  12  typically form seals at seams  22 ,  24 , respectively. However, it is also contemplated to utilize a gasket between the left and right end caps  26 ,  28  and the left and right ends  18 ,  20 , respectively, to form the seals. 
   A cooling medium, typically water, is supplied to the laser  10  through an inlet  30 , typically attached to the left end cap  26 . The cooling medium exits the laser  10  through an outlet  32 , typically attached to the right end cap  28 . The inlet  30  and the outlet  32  both have at least one ridge  34 ,  36 , respectively, around the perimeter for securing tubes (not shown) thereto. 
   Referring to  FIG. 2 , the cooling medium passes through a left passage  38  in the left end cap  26  and into a cavity  40  in the housing  12  where the cooling medium fills the cavity  40 . A glass tube  41  is positioned into the cavity  40  wherein the glass tube  41  is adjacent a cavity surface  39 . The glass tube  41  prevents corrosion to the cavity surface  39  which can be caused by contact between the cooling medium and the surface  39  defining the cavity  40  over time. 
   The cooling medium exits the right end  24  of the housing  12  and passes through a right passage  42  in the right end cap  28  and out of the laser  10  through the outlet  32 . Depending upon the configuration of the laser  10 , the flow of the cooling medium may be reversed. 
   A flash lamp  44  and a laser rod  46  are positioned in selected positions within the cavity  40  in a substantially parallel configuration. Ends  52 ,  54  of the flash lamp  44  extend beyond the left and right ends  22 ,  24  of the housing  12  and are positioned within through bores  56 ,  58  in the left and right end caps  26 ,  28 , respectively. Positioning the ends  52 ,  54  of the flash lamp  44  within the through bores  56 ,  58  secures the flash lamp  44  in a selected position within the cavity  40 . Referring to  FIG. 5 , gaskets such as O-rings  31  are typically utilized to form a seal between the end caps  26 ,  28  and the ends  52 ,  54  of the flash lamp  44  to retain the liquid coolant within the cavity  40 . 
   Ends  60 ,  62  of the laser rod  46  are positioned through bores  64 ,  66  in the left and right end caps  26 ,  28 , respectively such that the laser rod ends  60 ,  62  extend beyond the end caps  26 ,  28 . Positioning the ends  60 ,  62  within the through bores  64 ,  66  secures the laser rod  46  in a selected position within the cavity  40  such that the axis  48  of the flash lamp  44  is substantially parallel to an axis  50  of the laser rod  46 . Gaskets such as  0 -rings  31  are utilized to form a seal between the end caps  26 ,  28  and the ends  60 ,  62  of the laser rod  46  to retain the liquid coolant within the cavity  40 . 
   The through bore  66  provides an opening through which a laser beam is directed from the hand held laser  10 . A diameter of the laser beam is equivalent to the diameter of the laser rod  46  which is typically about 5 mm. However the diameter of the beam, as well as a shape of the beam, can be varied by manipulating a collimator (not shown) positioned beyond the through bore  66 . The collimator is capable of reducing the diameter of the beam to less than one millimeter. It is also contemplated that the beam be separated into multiple beams through beam splitting techniques. 
   The laser rod  46  is typically an Er:YAG laser rod that is designed to deliver between about 1.2 J/cm 2  and about 1.5 J/cm 2  at a frequency of about 2940 nm. The laser rod  46  is typically about 5 mm in diameter and about 80 mm in length. However, other laser mediums besides an Er:YAG laser are also contemplated as well as a laser that delivers a different amount of energy at a different frequency. It is also contemplated to utilize a laser rod  46  having a diameter and length different than a 5 mm diameter and an 80 mm length, provided the laser rod  46  is of a size that can be utilized as a hand-held laser  10 . 
   Referring to  FIG. 6 , power is supplied to the flash lamp  44  through an umbilical cord  60  that also supplies the cooling medium and other utilities including electricity and optionally a compressed coolant gas that may be required for the laser  10  to properly function. Typically, the umbilical cord  60  attaches to the left end cap  26 . However, the umbilical cord  60  can also be attached to the housing  12  as well as the right end cap  28  to supply the necessary utilities to the laser  10 . 
   Power is supplied through a connection  66  to the flash lamp  44  typically in intervals in rapid succession, otherwise referred to as “pumping”. As the flash lamp  44  is pumped, the flash lamp  44  supplies energy to the laser rod  46  in the form of light energy. The energized laser rod  46  then supplies the laser beam through an aperture  68  in the casing  62  that is utilized in the medical treatment. 
   As the flash lamp  44  is pumped and the laser rod  46  is energized, a significant amount of heat is generated. Some of the heat is removed from the laser  10  by circulating the cooling medium through the cavity  40 . As the cooling medium passes through the cavity  40 , the cooling medium contacts the laser rod  46 , the flash lamp  44  and the glass liner  41  to remove heat from the laser  10 . The cooling medium typically flows in a direction of arrows illustrated in  FIG. 2  within the cavity  40  substantially along the axis  48 ,  50  of the flash lamp  44  and the laser rod  46  while removing heat from the laser  10 . 
   Heat is also removed from the laser  10  by transferring heat into the atmosphere through the exterior surface  16  of the housing  12  that includes the plurality of fins  14  which increase the surface area of the exterior surface  16 . Typically, the laser  10  will be contained within an enclosed casing  62  where a forced gaseous cooling medium, typically air, is supplied to the casing  62  through the umbilical cord. The gaseous cooling medium passes over the outer surface of the laser  10  the plurality of fins  14  to remove heat from the housing  12 . The casing  62  also typically includes an outlet  64  for the forced gaseous cooling medium to exit the casing. 
   Heat is also removed from the laser through the end caps  26 ,  28  which are in thermal contact with the housing  12 . Heat is dissipated through the end caps  26 ,  28  and into the surrounding atmosphere, typically the forced gaseous medium, to aid in cooling the laser  10 . The end caps  26 ,  28  are typically constructed of aluminum to minimize the weight of the laser  12 . However, other materials of construction of the end caps  26 ,  28  are also contemplated. 
   Referring to  FIGS. 3-5 , the cavity  40  has a substantially elliptical cross-section that is defined by the surface  39  which increases the efficiency of the laser  10 . The elliptical configuration redirects the light energy from the flash lamp  44  into the laser rod  46  more efficiently than other configurations of the cavity  40 , such as a circular cross-sectional cavity. The elliptical surface  39  is typically coated with a reflective material, typically gold, to increase the amount of light energy that redirected into the laser rod  46 . However other reflective materials such as, but not limited to, silver and titanium are also contemplated. Other cross-sectional configurations of the cavity  40  that are less efficient than an elliptical cross-sectional cavity  40  are also contemplated, including but not limited to including a circular cross-section. 
   Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.