WO2022022887A1

WO2022022887A1 - Radio-frequency method for treating the skin

Info

Publication number: WO2022022887A1
Application number: PCT/EP2021/066188
Authority: WO
Inventors: Matthew Prokop; Ralf Hagens; Thomas SCHORNSTEIN; Sören JASPERS; Martin Sattler; Daniel Philip MCGRAW; Isobel Jane ASHBEY
Original assignee: Beiersdorf Ag
Priority date: 2020-07-29
Filing date: 2021-06-16
Publication date: 2022-02-03
Also published as: DE102020209532A1

Abstract

The invention relates to an improved method for injecting heat into the skin, in particular into the dermis.

Description

Beiersdorf AG

Procedure for radiofrequency treatment of the skin

The present invention relates to a skin care device using high frequency waves. According to one aspect of the present invention, there can be provided a skin care device using high frequency waves, the device comprising: a main body that can be held by a user; a head disposed on one side of the main body, including an electrode unit for applying a high-frequency current to a user's skin and being adapted to come into contact with the user's skin; and a drive unit for generating a high-frequency current and for supplying it to the electrode unit, wherein: the electrode unit comprises a first pair of electrodes and a second pair of electrodes which are arranged symmetrically, the pairs of electrodes being arranged crosswise, wherein the high-frequency pulses introduced into the skin become one lead to warming of the dermis.

Methods and devices for introducing high-frequency waves are sufficiently available in the prior art. The simplest process is the application of high-frequency waves directly to the affected skin area. The disadvantage of this type of high-frequency treatment is that the heating occurs very unspecifically in all layers of the skin.

A device is known from US Pat. No. 9,844,682 B2 which, by means of six electrodes arranged in a row, causes the skin to be heated by specific pulse sequences.

US Pat. No. 9,827,437 B2 describes a device for skin treatment with high-frequency waves, which introduces the high-frequency current into the skin by means of concentrically arranged ring-shaped electrodes. Here, too, no deep-lying areas of the skin can be heated.

In order to achieve a skin-tightening effect, however, it is necessary for the heating to take place in the deeper layers of the skin (dermis) so that the heat shock proteins (HSP) in the dermis are activated. These HSPs ensure orderly collagen synthesis and thus wrinkle-free skin.

The person skilled in the art has therefore long been concerned with improving the introduction of high-frequency into the dermis. The methods for introducing high-frequency into the skin that can be found in the prior art and are familiar to a person skilled in the art have some disadvantages with regard to large-area and not deep-reaching heating.

It was necessary to remedy these disadvantages.

It was surprising for the person skilled in the art that the high-frequency introduction depends very much on the activation and arrangement of the electrodes with which the high-frequency is introduced into the skin.

The invention therefore relates to an improved device for delivering radio frequencies into the skin, particularly into the dermis, the device comprising: a main body which can be held by a user; a head disposed on one side of the main body, the head having an electrode unit for applying a high-frequency current to a user's skin, the head being adapted to come into contact with the user's skin; and a drive unit for generating a high-frequency current and for supplying it to the electrode unit, characterized in that the electrode unit comprises a first pair of electrodes A and a second pair of electrodes B, wherein the pairs of electrodes A and B themselves can be constructed from two or more individual electrodes, the two or more individual electrodes are arranged linearly and symmetrically to one another, with the electrode pairs A and B being arranged perpendicularly (crosswise), with the intersection of the linearly arranged electrode pair A and the linearly arranged electrode pair B being in the middle of the respective electrode pair A and B and wherein the radiofrequency pulses introduced into the skin via the electrode pairs A and B result in heating of the dermis.

FIG. 1 shows a schematic representation of an inventive device. The main body 1 is formed into a disk-shaped head 2 at one end. The head 2 carries on its surface 3 the pairs of electrodes A and B, each of which consists of six individual electrodes 4A1 to _4A6 and _4B1 to _4B6 arranged linearly with respect to one another.

The individual electrodes 4A1 to _4A6 and _4B1 to _4B6 are each driven individually with high-frequency pulses via the drive unit 5, the drive unit being arranged inside the main body.

The energy required for operation can be provided by accumulators or batteries or via a connection to an external voltage/current source (not shown). The individual electrodes are advantageously controlled in such a way that only two opposite individual electrodes from the electrode pair A and two opposite individual electrodes from the electrode pair B are alternately supplied with a high-frequency voltage.

If the electrode pairs A and B have more than two individual electrodes, then the actuation takes place in such a way that the pulse sequence of the electrode pair A and/or B does not in each case have a direct repetition in the actuated individual electrodes.

A "rotating" alternating field WF always occurs in the area (FIG. 5)

The control sequence for a device with 6 individual electrodes per pair of electrodes A and B is shown schematically in FIG. Two electrodes from groups A and B are always activated at the same time (e.g. electrodes A1 and A4) and then a pair from the second electrode group (e.g. electrodes B1 and B4). This activation corresponds to so-called time multiplexing.

FIG. 3 shows a control sequence for a device with 6 individual electrodes per pair of electrodes A and B, in which two individual electrodes of the pair of electrodes A and B are controlled simultaneously. (e.g. electrodes A1 and A4 together with electrodes B1 and B4)

According to the invention, the frequency for the control is between 10 Hz and 10 kHz.

According to the invention, the radio frequency applied to the electrodes is between 1 and 6 MHz. It is advantageous if opposite electrodes are driven with a phase shift of 90°.

Advantageously, four electrodes in a square configuration are active at any time, with the voltage on a single opposing pair of electrodes 90 degrees out of phase with pair B, which is perpendicular to A. Due to the phase shift of the pairs of electrodes A and B, there is no local overheating of the dermis and epidermis in the corner points (FIG. 8 and FIG. 6 and FIG. 7 in connection with Table 1). The device sequentially cycles through several sets of electrodes, with the frequency of switching between sets being nominally 10 Hz. However, the electronics can be configured up to 10 kHz. Thus, in the nominal configuration, each set of electrodes is active for a time of 100 ms between switching.

A very flat heat zone in the skin can be achieved through the alternating pairwise activation. For the purposes of the invention, a flat thermal zone is understood to mean a zone extending across all electrodes with a higher temperature than the surrounding areas, the flat thermal zone being larger in terms of area but not deeper or insignificantly deeper than the thermal zone that occurs when only one is activated Electrode pair arises. FIG. 4 schematically shows the formation of the heat zones X with sequential activation of the individual electrodes.

Passing through several pairs of electrodes makes it possible to heat the center at the same rate while reducing local heating in the epidermis under the electrodes.

With three pairs of electrodes, each electrode is only used (driven) 1/3 of the time, while the middle piece of the dermis

in Figure 4) is heated all the time. This improves the utility by 5 dB.

Devices according to the invention generate a temperature increase of up to 5 K at a depth of 1 mm in the skin.

The dermis is the conductive layer where electricity finds the path of least resistance.

The epidermis has a higher heat capacity than the dermis. This means that a higher energy input into the epidermis is required to heat it up than the energy required to heat up the dermis.

The inventive method aims at heating the dermis, in which the healing cascade triggered by the heating produces an anti-aging effect, in particular skin tightening and a reduction in the appearance of wrinkles. For this purpose, the thermal and electrical properties of the dermis are used in a targeted manner.

It is particularly advantageous to cool the electrodes from the rear. The cooling is advantageously carried out by a Peltier element which is arranged on the back of the electrodes and which is in thermally conductive contact with the electrodes. As a result, overheating of the epidermis can be prevented even when there is a high input of energy into the dermis.

Evidence for the improved heating of the dermis:

Experimental setup: thermal imaging camera for recording the surface temperature data, as well as 2 glass fiber thermometers in the dermis approx. 1 mm below the surface.

Figure 8 shows thermal camera surface images taken immediately after the device was removed. When using cooled electrodes _, the temperature of the epidermis is 6 Kelvin (K) lower.

In Figure 8, it can be seen that for the cooled electrode configuration, the temperature directly beneath the electrodes in the epidermis is cooler than the central target area where the desired 5 degree temperature rise was recorded, as shown in the fiber optic measurements of the dermis.

Table 1 shows the temperature profile (in degrees Celsius) measured in the dermis

The position of the temperature measurement point can be seen in FIG. 6 for channel 1 (channel 1) and in FIG. 7 for channel 2 (channel 2).

Claims

patent claims

Claims 1. A device for injecting radio frequencies into the skin, particularly the dermis, the device comprising: a main body that can be held by a user; a head disposed on one side of the main body, the head having an electrode unit for applying a high-frequency current to a user's skin, the head being adapted to come into contact with the user's skin; and a drive unit for generating a high-frequency current and for supplying it to the electrode unit, characterized in that the electrode unit comprises a first pair of electrodes A and a second pair of electrodes B, wherein the pairs of electrodes A and B themselves can be constructed from two or more individual electrodes, the two or more individual electrodes are arranged linearly and symmetrically to one another, with the electrode pairs A and B being arranged perpendicularly (crosswise), with the intersection of the linearly arranged electrode pair A and the linearly arranged electrode pair B being in the middle of the respective electrode pair A and B and wherein the radiofrequency pulses introduced into the skin via the electrode pairs A and B result in heating of the dermis.

2. Device according to at least one of the preceding claims, characterized in that the device runs through several sets of electrodes in succession, the frequency of switching between the sets having a nominal value of 10 Hz.

3. Device according to at least one of the preceding claims, characterized in that the electronics can be configured up to 10 kHz, with each set of electrodes being active for a time of 100 ms between switching in the normal configuration.

4. Apparatus according to at least one of the preceding claims, characterized in that four electrodes which are in a square configuration are active at any instant in time, the voltage on a single opposing pair of electrodes being 90 degrees out of phase with pair B which is perpendicular to A is arranged. Device according to at least one of the preceding claims, characterized in that the electrodes are actively cooled, the cooling advantageously being effected by a Peltier element which is arranged on the back of the electrodes and which is in thermally conductive contact with the electrodes.