Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS20060047281 A1
Publication typeApplication
Application numberUS 10/931,271
Publication dateMar 2, 2006
Filing dateSep 1, 2004
Priority dateSep 1, 2004
Also published asUS8579896, US20100185193, US20100185194, US20110137386, US20110196363, US20130289554
Publication number10931271, 931271, US 2006/0047281 A1, US 2006/047281 A1, US 20060047281 A1, US 20060047281A1, US 2006047281 A1, US 2006047281A1, US-A1-20060047281, US-A1-2006047281, US2006/0047281A1, US2006/047281A1, US20060047281 A1, US20060047281A1, US2006047281 A1, US2006047281A1
InventorsMichael Kreindel
Original AssigneeSyneron Medical Ltd.
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and system for invasive skin treatment
US 20060047281 A1
Abstract
A system and method for simultaneously heating a plurality of discrete skin volumes to a coagulation temperature. The system comprises an applicator containing an electrode having a plurality of spaced apart protruding conducting elements configured to contact the skin surface at a plurality of discrete locations. A controller applies a voltage to the electrode so as to simultaneously heat a plurality of skin volumes to a coagulation temperature when the applicator is applied to the skin surface.
Images(3)
Previous page
Next page
Claims(20)
1. A system for simultaneously heating a plurality of discrete skin volumes to a coagulation temperature, comprising:
(a) an applicator comprising at least one electrode having a plurality of spaced apart protruding conducting elements configured to contact the skin surface at a plurality of discrete locations; and
(b) a voltage source configured to apply a voltage to the at least one electrode so as to generate an electrical current in the skin causing simultaneously heating of a plurality of skin volumes to a coagulation temperature when the applicator is applied to the skin surface.
2. The system according to claim 1 further comprising means for cooling the skin surface.
3. The system according to claim 1 wherein the voltage source is configured to apply voltage pulses to the electrodes.
4. The system according to claim 3 wherein the pulses have a duration of less than 0.2 sec.
5. The system according to claim 1 wherein the conducting elements are configured to penetrate the epidermis when the applicator is applied to the skin.
6. The system according to claim 1, wherein the protruding conducting elements have blunt tips.
7. The system according to claim 1 wherein the protruding elements have a diameter of 0.5 mm.
8. The system according to claim 1 wherein the protruding elements have are spaced apart by a distance of at least 1 mm.
9. The system according to claim 1 wherein the voltage source is configured to apply a voltage to the skin so as to generate a current density at the tips of the protruding elements of at least 1 Ampere/cm2.
10. An applicator for use in the system of claim 1.
11. A method for simultaneously heating a plurality of discrete skin volumes to a coagulation temperature, comprising:
(a) applying an applicator to the skin surface, the applicator comprising at least one electrode having a plurality of spaced apart protruding conducting elements configured to contact the skin surface at a plurality of discrete locations; and
(b) applying a voltage to the electrode so as to generate an electrical current in the skin simultaneously heating a plurality of skin volumes to a coagulation temperature.
12. The method according to claim 11 further comprising cooling the skin surface.
13. The method according to claim 11 wherein the voltage is applied to the electrode in pulses.
14. The method according to claim 13 wherein the pulses have a duration of less than 0.5 sec.
15. The method according to claim 11 wherein the conducting elements penetrate the epidermis when the applicator is applied to the skin.
16. The method according to claim 15 further comprising providing a prepulse of RF energy to the skin surface in order to facilitate penetration of the protruding elements into the skin.
17. The method according to claim 11, wherein the protruding conducting elements do not penetrate the skin.
18. The method according to claim 11 wherein the protruding elements have a diameter of 0.5 mm.
19. The method according to claim 11 wherein the protruding elements have are spaced apart by a distance of at least 1 mm.
20. The method according to claim 11 wherein a current density of at least 1 Ampere/cm2 is generated at the tips of the protruding elements.
Description
FIELD OF THE INVENTION

The invention relates to methods and systems for skin treatment.

BACKGROUND OF THE INVENTION

Directed damage of the skin is used to stimulate regrowth of collagen and to improve skin appearance. A well known method of directed damage is ablating the epidermis using laser radiation having wavelengths strongly absorbed by water so as to heat the water to above boiling temperature. Typical lasers used for epidermis ablation are CO2 and Er:YAG lasers. Ablating the epidermis using RF (radiofrequency) current is described in U.S. Pat. No. 6,309,387. This treatment significantly reduces wrinkles and improves the skin appearance. The main disadvantages of skin resurfacing are the long healing period that can be over a month long and the high risk of dischromia. These disadvantages have reduced the popularity of ablative skin resurfacing in recent years.

Non-ablative skin resurfacing is based on heating of the dermis to a sub-necrotic temperature with simultaneous cooling of the skin surface. U.S. Pat. No. 5,810,801 describes penetrating the dermis with infrared laser radiation with dynamic cooling of the skin surface using a cryogen spray.

Wrinkles are created in skin due to the breakage of collagen fibers and to the penetration of fat into the dermal structure. Thus, destroying adipose cells and structure, can improve the surface structure. However, most wrinkle treatment methods target the collagen and do not have a significant effect on deep wrinkles. Radio frequency (RF) energy has been used for the treatment of the epidermal and dermal layers of the skin. For example, U.S. Pat. No. 6,749,626 describes use of RF for collagen formation in dermis. U.S. Pat. No. describes a method for collagen scar formation. U.S. Pat. Nos. 6,470,216, 6,438,424, 6,430,446, and 6,461,378 disclose methods and apparatuses for affecting the collagen matrix using RF with special electrode structures together with cooling and smoothing of the skin surface. U.S. Pat. Nos. 6,453,202, 6,405,090, 6,381,497, 6,311,090, 5,871,524, and 6,452,912 describe methods and apparatuses for delivering RF energy to the skin using a membrane structure. U.S. Pat. Nos. 6,453,202 and 6,425,912 describe methods and apparatuses for delivering RF energy and creating a reverse temperature gradient on the skin surface. Although a non-ablative treatment is much safer and does not scar the skin tissue, the results of non-ablative treatments are less satisfactory.

A method described in U.S. patent application No. 20030216719 attempts to maintain the efficiency of ablative treatment with a shorter healing time and a lower risk of adverse effects. The device described in that patent coagulates discrete regions of the skin where the regions have a diameter of tens of micrometers and the distance between the regions is larger than the regions themselves. This treatment provides skin healing within a few days but the results are very superficial and less spectacular than with CO2 laser treatment, even after multiple treatments.

U.S. Pat. No. 6,277,116 describes a method of applying electromagnetic energy to the skin through an array of electrodes and delivery electrolyte using a microporous pad.

A device for ablation of the skin stratum corneum using RF electrodes is described in U.S. Pat. Nos. 6,711,435, 6,708,060, 6,611,706, and 6,597,946. However, the parameters of this device are optimized for the ablation of the stratum corneum so as to enhance drug penetration into the skin, and not for thermal collagen remodeling.

SUMMARY OF THE INVENTION

The present invention provides a system and method for simultaneously heating skin at a plurality of discrete regions of the skin. The invention may be used for collagen remodeling. In accordance with the invention RF energy is applied to the skin at a plurality of discrete locations on the skin. The RF energy is applied using an electrode having a plurality of spaced apart protruding conducting pins. When the electrode is applied to the skin surface, each protruding conducting pin contacts the skin surface at a different location, so that the plurality of pins contacts the skin at a plurality of discrete locations. An RF voltage is then applied to the electrode so as to generate an electric current in the skin that heats the skin to a coagulation temperature simultaneously at a plurality of discrete regions of the skin. Coagulation temperatures are typically in the range of about 60° C. to about 70° C.

The protruding pins may have blunt tips which do not penetrate into the skin when the electrode is applied to the skin. In this case, the discrete regions of treated skin are located at the skin surface in the epidermis. Alternatively, the pins may have sharp tips that allow the protruding pin to penetrate the skin into the dermis. In this way, the discrete regions of treated skin are located in the dermis.

In another embodiment, the protruding elements are provided with sharp tips that allow the elements to penetrate into the skin. After application of the RF current in the skin, the protruding elements are pressed into the skin and an electrical current is then generated that coagulates tissue in the vicinity of the tip of each protruding element. The mechanical properties of the skin are changed after coagulation and the protruding elements may penetrate inside the skin without excessive pressure. A pre-pulse of RF energy can be applied to the skin in order to soften the skin tissue so as to facilitate penetration of the protruding elements into the skin.

The surface of the skin may be pre-cooled and/or cooled during the treatment to avoid damage to the skin in the area between protruding elements. Skin cooling may be provided by contact cooling or by applying a pre-cooled liquid or cryogen spray.

The invention may be used in wrinkle treatment, collagen remodeling, skin tightening, loose skin treatment, sub-cutaneous fat treatment or skin resurfacing.

Thus in its first aspect, the invention provides a system for simultaneously heating a plurality of discrete skin volumes to a coagulation temperature, comprising:

    • (a) an applicator comprising an electrode having a plurality of spaced apart protruding conducting elements configured to contact the skin surface at a plurality of discrete locations; and
    • (b) a controller configured to apply a voltage to the electrode so as to simultaneously heat a plurality of skin volumes to a coagulation temperature when the applicator is applied to the skin surface.

In its second aspect, the invention provides a method for simultaneously heating a plurality of discrete skin volumes to a coagulation temperature, comprising:

    • (a) applying an applicator to the skin surface, the applicator comprising an electrode having a plurality of spaced apart protruding conducting elements configured to contact the skin surface at a plurality of discrete locations; and
    • (b) applying a voltage to the electrode so as to simultaneously heat a plurality of skin volumes to a coagulation temperature.

In the case when protruding part of the electrode penetrates within the skin the size of protruding elements should be small enough to avoid significant damage of the skin surface. Preferable size of protruding elements is from 10 to 200 microns and coagulation depth can be varied from 100 microns up to 2 mm for invasive electrodes.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to understand the invention and to see how it may be carried out in practice, preferred embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

FIG. 1 shows a system for treating skin simultaneously at a plurality of discrete regions of skin, in accordance with the invention;

FIG. 2 shows an applicator for use in the system of FIG. 1;

FIG. 3 shows a second applicator for use in the system of FIG. 1; and

FIG. 4 shows a third applicator for use in the system of FIG. 1.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a system for applying RF energy to a plurality of discrete regions of skin in accordance with the invention. The system includes an applicator 13, to be described in detail below, configured to apply RF energy simultaneously to a plurality of discrete regions of skin of an individual 22. The applicator 13 is connected to a control unit 11 via a cable 12. The control unit 11 includes a power source 18. The power source 18 is connected to an RF generator 15 that is connected to electrodes in the applicator 13 via wires in the cable 12. The control unit 11 has an input device such as a keypad 10 that allows an operator to input selected values of parameters of the treatment, such as the frequency, pulse duration and intensity of the RF energy. The control unit 11 optionally contains a processor 9 for monitoring and controlling various functions of the device.

FIG. 2 shows an applicator 13 a that may be used for the applicator 13 in accordance with one embodiment of the invention. The applicator 13 a comprises an electrode 1 from which a plurality of protruding conducting elements 5 extend. Each protruding element 5 (referred to herein as a “pin”) terminates in a tip 7 having a high curvature. The electrical current from the tips is much higher than from flat parts 6 of the electrode. Skin volumes 4 around the tips 7 are therefore heated to a much higher temperature than the surrounding dermis 3 and epidermis 2, so that the skin volumes 4 may be heated to a coagulation temperature, while the skin temperature in the outside the volumes 4 are not heated to a coagulation temperature. The electrical energy is adjusted to selectively damage skin adjacent to tips so that the treatment of the skin occurs simultaneously at a plurality of discrete volumes 4. The pulse duration is preferably short enough to prevent significant heat diffusion far from the tips. In order to limit significant heat transfer from the tips, the pulse duration should preferably not exceed 200 ms. The selectivity of the treatment can be improved by electrode cooling of the skin surface. Cooling also causes a more uniform heat distribution at the tips. This can be achieved by circulating a cooling fluid through tubes 8 in the flat regions 9 between the pins 5. The electrode 1 is contained in a housing 10 connected to the cable 12. A wire 13 extending through the cable 12 electrically connects the electrode 1 with a terminal of the power source 18. A second terminal of the power supply 18 may be connected to a ground electrode 20 via a cable 23 (See FIG. 1).

FIG. 3 shows an applicator 13 b that may be used for the applicator 13 in accordance with another embodiment of the invention. The applicator 13 b comprises an electrode 100 consisting of a plurality of conducting pins 101 extending from a conducting plate 102. The pins 101 are separated by electrical insulating material 105. The applicator 13 b is used similarly as the applicator 13 a to deliver electrical current to discrete volumes of skin 4.

The pins 5 in the applicator 13 a and the pins 101 in the applicator 13 b are provided with blunt tips 7 and 107, respectively. This prevents the pins 5 and 101 from penetrating into the skin when the electrode 13 a or 13 b is applied t the skin surface. Thus, the applicators 13 a and 13 b provide simultaneous non-invasive coagulation of skin regions 4.

FIG. 4 shows an applicator 13 c that may be used for the applicator 13 in accordance with another embodiment of the invention. The applicator 13 c is configured to be used for invasive collagen remodeling. The applicator 13 c includes an electrode 201 having a plurality of protruding conducting pins 205. The pins 205 have sharp tips 206 that are configured to penetrate through the epidermis 202 into the dermis 203 when pressed on the skin as shown in FIG. 4. The applicator 13 c is used similarly to the applicators 13 a and 13 b so that the treatment of the skin occurs simultaneously in a plurality of discrete skin volumes 204. However, unlike the discrete volumes 4, which are located in the epidermis (see FIGS. 2 and 3), the volumes 204 are located below the surface in the dermis 203 (FIG. 4). This reduces skin redness that sometimes occurs when the treated regions are in the epidermis. A maximal current density is created at the tips of the pins 205. The sides of the protruding elements may be coated with insulating material to avoid skin heating around the pins 205 (not shown).

The present invention can be combined with other methods of skin treatment including laser treatment. For example non-ablative collagen remodeling by laser radiation may be combined with the invasive RF heating of the skin dermis in accordance with the invention.

The preferable parameters for non-invasive skin coagulation in accordance with the invention are as follows:

    • Electrode size above 0.3 cm;
    • Protruding element at contact with the skin up to 0.5 mm
    • Protruding element height about 1 mm.
    • Distance between protruding elements at least twice the element diameter;
    • Current density: over 1 A/cm2;
    • RF current pulse duration: not longer than 0.5 sec;
      • The optimal parameters for invasive skin coagulation:
    • Electrode size above 0.3 cm;
    • Pin diameter at contact with the skin not larger than 0.3 mm
    • Pin protruding height above 1 mm.
    • Distance between pins at least 1 mm;
    • Current density above 0.1 A/cm2;
    • RF current pulse duration not longer than 0.5 sec;
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7828734Jan 8, 2007Nov 9, 2010Slender Medical Ltd.Device for ultrasound monitored tissue treatment
US8216218Jul 10, 2008Jul 10, 2012Thermage, Inc.Treatment apparatus and methods for delivering high frequency energy across large tissue areas
US8512331Jun 14, 2012Aug 20, 2013Endymed Medical Ltd.Electrosurgical methods and devices employing phase-controlled radiofrequency energy
US8702691Jun 8, 2006Apr 22, 2014Thermage, Inc.Treatment apparatus and methods for delivering energy at multiple selectable depths in tissue
US8728071Feb 27, 2013May 20, 2014Endymed Medical Ltd.Systems and methods employing radiofrequency energy for skin treatment
US20080287943 *Jan 25, 2008Nov 20, 2008Thermage, Inc.Treatment apparatus and methods for inducing microburn patterns in tissue
US20100179531 *Dec 30, 2009Jul 15, 2010Solta Medical, Inc.Tissue treatment apparatus and systems with pain mitigation and methods for mitigating pain during tissue treatments
EP2401026A1 *Feb 22, 2010Jan 4, 2012Transpharma Medical, Ltd.Electrical skin rejuvenation
EP2730313A1 *Feb 22, 2010May 14, 2014Syneron Medical Ltd.Electrical skin rejuvenation
WO2008051402A2 *Oct 16, 2007May 2, 2008Apsara Medical CorpMethod and apparatus for carrying out the controlled heating of tissue in the region of dermis
WO2009072108A2 *Nov 23, 2008Jun 11, 2009Syneron Medical LtdA disposable electromagnetic energy applicator and method of using it
WO2010016848A1 *Aug 22, 2008Feb 11, 2010Jongju NaMethod, system, and apparatus for dermalogical treatment
WO2011010302A1 *Jul 12, 2010Jan 27, 2011Syneron Medical LtdA method and apparatus for fractional skin treatment
WO2014009875A2Jul 9, 2013Jan 16, 2014Koninklijke Philips N.V.Skin treatment method and apparatus
Classifications
U.S. Classification606/49
International ClassificationA61B18/14
Cooperative ClassificationA61B2018/1467, A61B2018/00452, A61B2018/143, A61B18/1477, A61B18/14, A61B18/18, A61B2018/1425
European ClassificationA61B18/14
Legal Events
DateCodeEventDescription
Mar 14, 2005ASAssignment
Owner name: SYNERON MEDICAL LTD., ISRAEL
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:KREINDEL, MICHAEL;REEL/FRAME:015772/0833
Effective date: 20041130