Tissue cooling rod for laser surgery

Abstract

A laser treatment device and process with controlled cooling. The device contains a cooling element with high heat conduction properties, which is transparent to the laser beam. A surface of the cooling element is held in contact with the tissue being treated while at least one other surface of the cooling element is cooled by the evaporation of a cryogenic fluid. The cooling is coordinated with the application of the laser beam so as to control the temperatures of all affected layers of tissues. In a preferred embodiment useful for removal of wrinkles and spider veins, the cooling element is a sapphire plate. A cryogenic spray cools the top surface of the plate and the bottom surface of the plate is in contact with the skin. In preferred embodiments the wavelength of the laser beam is chosen so that absorption in targeted tissue is low enough so that substantial absorption occurs throughout the targeted tissue. In a preferred embodiment for treating large spider veins with diameters in the range of 1.5 mm, Applicants use an Er:Glass laser with a wavelength of 1.54 microns.

Description

[0001]This application is a continuation-in-part application of U.S. Ser. No. 09 / 174,065 filed Oct. 16, 1998 U.S. Pat. No. 6,059,820. This invention relates to devices and methods for laser treatment and in particular to laser treatment with surface cooling.BACKGROUND OF THE INVENTION[0002]1. Prior Art Skin Cooling[0003]The principal methods presently used for skin cooling before or during the laser treatment involve the use of a cold contacting window or cryogenic spray device. Cryogenic spray directly to the skin may reduce a skin temperature below 0 C0° C. but can freeze the skin and cause significant damage to it. Typical cold contacting windows of the prior art utilize ice water at 0 C0° C. can cool the surface of the skin to as low as about 4 C4° C. But prior art ice water cooled cold contact window devices are inadequate to remove enough heat to prevent unwanted surface tissue damage in many applications.[0004]Three prior art techniques are described in the following United S...

AI Technical Summary

Benefits of technology

This method effectively controls tissue temperature during laser treatments, preventing unwanted damage by maintaining optimal skin and blood vessel temperatures, improving treatment outcomes for conditions like port wine stains and spider veins.

Problems solved by technology

Cryogenic spray directly to the skin may reduce a skin temperature below 0 C0° C. but can freeze the skin and cause significant damage to it.

Typical cold contacting windows of the prior art utilize ice water at 0 C0° C. can cool the surface of the skin to as low as about 4 C4° C. But prior art ice water cooled cold contact window devices are inadequate to remove enough heat to prevent unwanted surface tissue damage in many applications.

This method is normally not satisfactory.

The surface gets too cold and the subsurface layers are not sufficiently cooled so that unwanted damage occurs at the surface because the tissue gets too cold from the cryogen and / or unwanted damage occurs in the immediate subsurface layers because the tissue gets too hot from the laser beam.

The techniques do not work well for deeper, larger blood vessels.

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