Method of selective photothermolysis

Abstract

A method and apparatus for selective photothermolysis of a target tissue within surrounding tissue. The target and the surrounding tissue are heated to a predetermined temperature of about 60° C. by a pulsed heat source such as a flash lamp which creates a temperature gradient in the air included in a cavity formed between the housing of the apparatus and the surrounding tissue. The surface temperature of the tissue is monitored by a sensor unit. When the tissue surface reaches the predetermined temperature the target tissue is heated to the point of coagulation, preferably by narrow band electromagnetic radiation. The temperature difference between the coagulating target and the surrounding tissue is sufficiently mild that heat diffusing out of the target does not damage the surrounding tissue, even in the case of a relatively large target such as varicose veins. The heating action may be terminated by automatically pumping air or another suitable coolant into the cavity when the surface of the tissue reaches a preset value or by lifting the apparatus off the tissue. The apparatus may include a programmable controller which may be programmed locally or remotely with the treatment parameters.

What is claimed is:  
     
         1 . Apparatus for selective photothermolysis of a target tissue within the skin, the apparatus comprising: 
 a housing having an opening therein, said housing forming a cavity enclosing a volume of air when said opening is placed in contact with said skin;    a pulsable heat source disposed within said housing for rapidly heating said volume of air to form a temperature gradient therealong;    a pulsable source of narrow band electromagnetic radiation disposed within said housing for irradiating said skin with narrow band electromagnetic radiation to selectively heat said target tissue;    a sensing unit attached to said housing for sensing the temperature of said skin;    a controller unit connected to said heat source, said source of electromagnetic radiation and said sensor unit for controlling said heat source and said source of electromagnetic radiation, for coordinating the sequence of activation of said heat source and said source of electromagnetic radiation and for receiving signals from said sensor unit; and    at least one power source for energizing said heat source, said source of electromagnetic radiation and said controller.    
     
     
         2 . The apparatus according to  claim 1  wherein said cavity is a sealed cavity.