Radio frequency skin treatment

Abstract

A device for radio frequency (RF) skin treatment of skin of a user comprising an active electrode, a return electrode, an RF generator arranged to supply RF energy to the user's skin via the active and return electrodes. The return electrode having a planar skin contact surface extending in a main plane. The active electrode having a skin contact surface with a maximum dimension in a range from 100 μm to 500 μm. The surface area of the planar skin contact surface of the return electrode is at least 5 times larger than a surface area of the skin contact surface of the active electrode. The skin contact surface of the active electrode is arranged in a position at a distance from the main plane. The device may be used to control the dimensions and shape of a thermal lesion in the user's skin generated by the RF energy.

1 . A device for radio frequency (RF) skin treatment of skin of a user, the device comprising:
 an active electrode;   a return electrode having a planar skin contact surface extending in a main plane;   an RF generator arranged to supply, during use, RF energy to the skin of the user via the return electrode and the active electrode;   a surface area of the planar skin contact surface of the return electrode being at least 5 times larger than a surface area of the skin contact surface of the active electrode;   the skin contact surface of the active electrode arranged or arrangable in a position at a distance from the main plane, seen in a direction perpendicular to the main plane; and   wherein an outer surface of the device comprises an indentation, the active electrode arranged in a deepest portion of the indentation.   
     
     
         2 . The device according to  claim 1 , wherein the distance from the main plane is larger than 0.5 mm. 
     
     
         3 . The device according to  claim 1 , wherein the skin contact surface of the active electrode has a circular circumference with a diameter in a range from 100 μm to 500 μm. 
     
     
         4 . The device according to  claim 1 , wherein the return electrode surrounds the active electrode. 
     
     
         5 . The device according to  claim 1 , wherein the planar skin contact surface of the return electrode is annular. 
     
     
         6 . The device according to  claim 5 , wherein the planar skin contact surface has an inside diameter between 1 and 4 mm and a radial width between 1 and 5 mm. 
     
     
         7 . The device according to  claim 1 , wherein the indentation is dome shaped. 
     
     
         8 . The device according to  claim 8 , wherein at least an inner surface of the protrusion is made of an electrically insulating material. 
     
     
         9 . The device according to  claim 1 , wherein the active electrode is displaceable relative to the return electrode, and wherein the device further comprises adjusting means configured to adjust the distance between the contact surface of the active electrode and the main plane. 
     
     
         10 . The device according to  claim 9 , wherein the device comprises a skin-contact element which, in use, contacts the user's skin, wherein the skin-contact element comprises an opening having a main axis of extension, and wherein the active electrode is displaceably arranged in the opening and displaceable into a plurality of different positions along the main axis of extension. 
     
     
         11 . The device according to  claim 10 , wherein the device comprises a plurality of active electrodes, and wherein the skin-contact element comprises a plurality of openings, each active electrode displaceably arranged in a corresponding one of the openings. 
     
     
         12 . The device according to  claim 1 , wherein a concentration of electric field lines in the skin in a region immediately below the active electrode results in the creation of a local lesion generated immediately below the active electrode. 
     
     
         13 . The device according to  claim 1 , wherein the skin surface level underneath the active electrode is different than the skin surface level underneath the return electrode. 
     
     
         14 . The device according to  claim 11 , wherein the skin surface level underneath the active electrode is below the skin surface level underneath the return electrode. 
     
     
         15 . The device according to  claim 11 , wherein the distance between the skin contact surface and the main plane is larger than 20% of the diameter of the skin contact surface of the active electrode. 
     
     
         16 . The device according to  claim 11 , wherein the distance between the skin contact surface and the main plane is larger than 50% of the diameter of the skin contact surface of the active electrode. 
     
     
         17 . The device according to  claim 1 , wherein the device comprises a rotatable assembly and a plurality of active electrodes arranged in the rotatable assembly. 
     
     
         18 . The device according to  claim 17 , wherein the rotatable assembly comprises a cylindrical skin-contact element comprising a plurality of openings, wherein each active electrode from among the plurality of active electrodes is displaceably arranged in a corresponding one of the openings. 
     
     
         19 . The device according to  claim 18 , wherein the rotatable assembly comprises transmission means rotatably arranged inside the rotatable assembly and arranged to control the positions of the active electrodes in the openings. 
     
     
         20 . The device according to  claim 19 , wherein the transmission means enable an automatic setting of the positions of the active electrodes in the openings and a distance between the skin contact surface of each of the active electrodes and the main plane of the single return electrode.