Device and method for fractional RF treatment of the skin

A method for reducing pain during skin treatment, comprising steps of:

• a. providing a non-deployable device for treating skin, configured to deliver energy in a pre-determinable pattern comprising:
• i. at least one treatment tip comprising N non-deployable electrodes and N resistors, N being an integer greater than or equal to 1, at least one of said N electrodes having at least one protruding conducting element;
• configured to penetrate a surface of the skin at least one discrete location;
• at least one of said N electrodes is configured to apply said energy to at least one discrete skin volume so as to heat said at least one discrete skin volume;
• at least one of said protruding conducting element having cross sectional area selected from a group consisting of:
• a triangular cross section, an arcuate cross section in which at least one side rib is curved inward, an arcuate cross section in which at least one side rib is curved outward and any combination thereof;
• each of said at least one of said protruding conducting element being characterized by dimensions of height A, length B of at least one side rib and an angle θ between at least two of said side ribs;
• at least one said protruding conducting element being configured to penetrate the skin surface at one or more discrete location;
• a ratio A/B being in a predetermined range;
• ii. an applicator comprising at least one energy generator configured to apply said energy to said at least one discrete skin volume by means of at least one of said N electrodes and said at least one spaced apart protruding conducting element;
• iii. at least one switch configured to reversibly electrically connect said at least one energy generator to at least one of said N electrodes;
• and
• iv. at least one temperature sensor;
• b. activating said at least one energy generator such that electrical current is suppliable to at least one of said N electrodes;
• wherein said method further comprising steps of:
• c. activating said at least one switching module according to a predetermined sequence, the sequence comprising:
• i. activating at least one of said at least one switch, said activation creating an electrical connection between said at least one energy generator and at least one of said N electrodes, thereby delivering said energy to said at least one discrete skin volume through said at least one of said N electrodes for a predetermined pulse duration t1;
• ii. deactivating said at least one of said at least one switch;
• iii. waiting a predetermined delay time t2;
• and,
• iv. repeating steps (i)-(iii) until said treatment is complete;
• thereby applying at least a portion of said energy to said at least one discrete skin volume via said electrical connection;
• d. switching the voltage and current for each of said N electrodes to another one of said N electrodes in a pre-defined sequence, providing fractional RF treatment to said skin;
• and
• e. activating said temperature sensor to determine temperature and amount of heating and ablation of said skin;
• wherein at least one of the following is being held true:
• (a) said at least one switch is configured to connect a number M of said N electrodes to said at least one energy generator such that merely said M electrodes are active electrodes through which voltage is applied to said at least one discrete skin volume to heat the same;
• and, the remaining N-M of said N electrodes are return electrodes;
• further wherein electrical current is returned from said M active electrodes to said at least one energy generator through said N-M return electrodes and N-M resistors, thereby said electrical current returned to said at least one energy generator is distributed among all of said N-M return electrodes, where M is an integer in the range from 1 to N;
• (b) Q second switches connecting a number O of said return electrodes to said at least one energy generator, such that electrical current is returned from said M active electrodes to said at least one energy generator through said O return electrodes and Q second switches, thereby said electrical current returned to said at least one energy generator is distributed among all of said O return electrodes;
• where Q is an integer in the range from 1 to N;
• O is an integer in the range from 1 to N-M;
• (c) said system additionally comprising at least one switching module comprising a first line, a return line, N switches and at least one selected from a group consisting of said N second switches, said N resistors and any combination thereof;
• said first line and said return line electrically connectable to said at least one energy generator;
• and
• for each pth switch, 1≤p≤N,
• said pth switch is electrically connected on a first side to said first line;
• said pth switch is electrically connected on a second side to either a pth resistor or a pth second switch, and electrically connectable to a pth electrode;
• said pth switch is configured, when closed, to enable passage of electric current from said at least one energy generator through said first line and through said switch to said pth electrode, and from said pth electrode through said return line to said at least one energy generator;
• and,
• said pth switch configured, when open, to prevent passage of electric current from said at least one energy generator to said pth electrode;
• a resistance of each of said N resistors being configured to generate a return path of current from said pth electrode via all other of said N electrodes, said current being divided between among said all other of said N electrodes, distributing said current homogeneously across said all other of said N electrodes and minimizing pain to a user;
• (d) the system further comprises at least one flexible connector and at least one contactor, wherein electrical connection between said applicator and the at least one of the N electrodes is via at least one of the at least one flexible connector and at least one of the at least one contactor, wherein at least one of the at least one flexible connector comprises a coil spring, wherein a distal portion of the at least one contactor contacts at least one electrode contact, wherein each of the at least one electrode contact a proximal end of one of the N electrodes, wherein the coil spring is proximal to the distal portion of the at least one contactor, and wherein a proximal portion of the at least one contactor is enclosed within a bore of the coil spring.