A skin treatment device with power adjustment

Abstract

There is provided a skin treatment device, comprising: one electrode configured to come into electrically conductive contact with a skin of a user; a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the electrode such that a radio frequency electromagnetic energy is applied to the skin; a first and second temperature sensors configured to measure a temperature of the skin; and one processor in operable communication with the radio frequency electromagnetic signal generator, wherein the processor is configured to execute program instructions, wherein the program instructions are configured to cause the processor to control the radio frequency electromagnetic signal generator to vary a power of the radio frequency electromagnetic energy applied to the skin based on the measured temperature of the skin according to a power-temperature relationship so as to maintain a target temperature of the skin.

Description

[0001] A SKIN TREATMENT DEVICE WITH POWER ADJUSTMENT

[0002] TECHNOLOGICAL FIELD

[0003] The present disclosure generally relates to a skin treatment device, and more particularly to a skin treatment device in which parameters of a radio frequency electromagnetic energy applied to the skin, such as power and / or voltage, are controlled.

[0004] BACKGROUND

[0005] One goal of various beauty treatments is tightening of the skin so as to give the skin a smooth and non-wrinkled appearance. Various treatments for tightening the skin have been developed and applied over the centuries.

[0006] Massaging the skin has been considered to lead to skin tightening. Application of massage is claimed by proponents to benefit the skin by stimulating the vascular system, as well as by promoting the drainage of lymph from skin tissue. In addition to manual massage, various mechanical devices have been developed to massage the skin in a consistent and repeatable manner.

[0007] Other treatments for the skin are based on selective electro-thermolysis. In selective electro-thermolysis, layers of the skin are subjected to heating. In particular, delivery of radiofrequency (RF) electromagnetic energy to layers of the skin has been promoted as an effective way of heating the skin in a controlled manner for treatment purposes. Application of RF energy as a skin treatment has been described as increasing cell metabolism rates, increasing blood flow to the skin, causing adipocyte necrosis (shrinking of fat cells), and as stimulating remodeling of collagen.

[0008] Certain treatments include a combination of massaging and simultaneous application of radiofrequency (RF) electromagnetic energy to the skin.

[0009] It is an object of the present disclosure to provide a device for improved treatment of the skin with improved safety.

[0010] Other aims and advantages of the present disclosure will become apparent after reading the present description and reviewing the accompanying drawings.

[0011] 02999686\34-01 GENERAL DESCRIPTION

[0012] In one aspect, there is provided a skin treatment device. The skin treatment device comprises at least one electrode configured to come into electrically conductive contact with a skin of a user. The skin treatment device comprises a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the at least one electrode such that a radio frequency electromagnetic energy is applied to the skin. The skin treatment device comprises a first temperature sensor configured to measure a first temperature of the skin. The skin treatment device comprises a second temperature sensor configured to measure a second temperature of the skin, the first temperature sensor and the second temperature sensor being spaced apart such that the first temperature of the skin is measured at a spaced apart location from a location at which the second temperature of the skin is measured. The skin treatment device comprises at least one processor in operable communication with the radio frequency electromagnetic signal generator, wherein the at least one processor is configured to execute program instructions, wherein the program instructions are configured to cause the at least one processor to control the radio frequency electromagnetic signal generator to vary a power of the radio frequency electromagnetic energy applied to the skin according to a powertemperature relationship so as to maintain a target temperature of the skin, and wherein the power-temperature relationship is defined to use as input one or more temperature variation metric being a function of the first temperature and the second temperature.

[0013] In embodiments, the one or more temperature variation metric includes a combined measured temperature, for example an average of the first temperature and the second temperature or any other combined function thereof, and if the combined measured temperature is below the target temperature, the power-temperature relationship is such that the radio frequency electromagnetic signal generator progressively decreases the power as the combined measured temperature gets closer to the target temperature of the skin.

[0014] In embodiments, if the combined measured temperature is below the target temperature, the power-temperature relationship is such that the power is varied linearly or inversely proportionally with respect to the difference between the target temperature and the combined measured temperature. In embodiments, the power-temperature relationship is such that the power is nonzero when the combined measured temperature is between a target temperature of the skin and a critical high temperature of the skin.

[0015] In embodiments, the power-temperature relationship is such that the power is nonzero when the combined measured temperature is equal to the target temperature.

[0016] In embodiments, if the combined measured temperature is above the target temperature and below a critical high temperature, the power-temperature relationship is such that the power is decreased inversely proportionally with respect to the difference between the target temperature and the combined measured temperature.

[0017] In embodiments, the power-temperature relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the first temperature, the second temperature, an average or some other combined function thereof exceeds a critical high temperature of the skin.

[0018] In embodiments, the power-temperature relationship is such that the power of the radio frequency electromagnetic energy applied to the skin is a maximum set power when the combined measured temperature is below a base low temperature.

[0019] In embodiments, the skin treatment device further comprises a user interface, and wherein the user interface is configured such that the maximum set power can be set by the user through the user interface.

[0020] In embodiments, the power-temperature relationship is such that: (a) the power is a maximum set power when the combined measured temperature is below a base low temperature; (b) the power is varied inversely proportional to the difference between the target temperature and the combined measured temperature when the combined measured temperature is greater than the base low temperature and below the target temperature; and (c) the power is stopped if the combined measured temperature exceeds a critical high temperature.

[0021] In embodiments, the one or more temperature variation metric includes a temperature difference between the first temperature and the second temperature or a function thereof and the power-temperature relationship is such that the radio frequency electromagnetic signal generator varies the power when said temperature difference exceeds a predetermined threshold. In embodiments, the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic signal generator stops the power when said temperature difference exceeds the predetermined temperature threshold.

[0022] In embodiments, the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic energy applied to the skin is stopped if the temperature difference between the first temperature and the second temperature exceeds a predetermined temperature difference threshold for more than a predetermined time threshold.

[0023] In embodiments, the first temperature sensor and the second temperature sensor are independent from each other.

[0024] In embodiments, the first temperature sensor and the second temperature sensor are connected to different microcontroller unit (MCU) channels.

[0025] In embodiments, the power-temperature relationship is also dependent on the variation over time of the temperature difference between the first temperature and the second temperature.

[0026] In some embodiments, the at least one electrode and at least one of said first and second temperature sensors are incorporated in at least one distally extending arm of the device which is configured to contact the skin of the user.

[0027] In some embodiments, the device comprises at least two distally extending arms, and wherein the first temperature sensor is incorporated on one arm and the second temperature sensor is incorporated on the other arm.

[0028] In some embodiments, the arms are movable for massaging the skin.

[0029] In some embodiments, the arms are stationary.

[0030] In some embodiments, at least one arm is movable and at least one other arm is stationary.

[0031] In embodiments, the step of varying the power of the radio frequency electromagnetic energy applied to the skin comprises: (a) determining an impedance of the skin; and (b) varying a voltage of the radio frequency electromagnetic signal based on the determined impedance of the skin according to a voltage-impedance relationship thereby varying the power of the radio frequency electromagnetic energy applied to the skin. In embodiments, the voltage-impedance relationship is such that the voltage of the radio frequency electromagnetic signal applied to the skin is higher with higher determined impedance of the skin.

[0032] In embodiments, the voltage-impedance relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is below a critical low impedance.

[0033] In embodiments, the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic energy applied to the skin is started if the measured impedance increases above a starting threshold impedance.

[0034] In embodiments, the voltage-impedance relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is above a critical high impedance.

[0035] In another aspect, there is provided a skin treatment device. The skin treatment device comprises at least one first electrode configured to come into electrically conductive contact with a skin of a user. The skin treatment device comprises at least one second electrode configured to come into electrically conductive contact with a skin of a user. The skin treatment device comprises a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the at least one first electrode and the at least one second electrode such that a radio frequency electromagnetic energy is applied to the skin. The skin treatment device comprises at least one processor in operable communication with the radio frequency electromagnetic signal generator. The at least one processor is configured to execute program instructions. The program instructions are configured to cause the at least one processor to control the radio frequency electromagnetic signal generator to vary a voltage of the radio frequency electromagnetic signal based on an impedance of the skin according to a voltage-impedance relationship, the impedance of the skin being measured between the at least one first electrode and the at least one second electrode.

[0036] In embodiments, the voltage-impedance relationship is such that the voltage of the radio frequency electromagnetic signal applied to the skin is higher with higher measured impedance of the skin. In embodiments, the voltage-impedance relationship is such that the square of the voltage of the radio frequency electromagnetic signal applied to the skin is varied proportionally with the measured impedance of the skin.

[0037] In embodiments, the skin treatment device comprises at least one temperature sensor configured to measure the temperature of the skin. The radio frequency electromagnetic signal generator is configured to vary a power of the radio frequency electromagnetic energy applied to the skin according to a power -temperature relationship so as to maintain a target temperature of the skin.

[0038] In embodiments, wherein the radio frequency electromagnetic signal generator is configured to vary the voltage of the radio frequency electromagnetic signal based on the measured impedance of the skin according to the voltage-impedance relationship thereby varying the power of the radio frequency electromagnetic energy applied to the skin.

[0039] In embodiments, the voltage-impedance relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is below a critical low impedance.

[0040] In embodiments, the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic energy applied to the skin is started if the measured impedance increases above a starting threshold impedance.

[0041] In embodiments, the voltage-impedance relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is above a critical high impedance.

[0042] In embodiments, the voltage-impedance relationship is also dependent on a variation over time of the measured impedance. In embodiments, the voltage-impedance relationship is also dependent on a variation over time of the measured impedance including a variation of impedance between two separate treatments.

[0043] In a further aspect, there is provided a skin treatment device. The skin treatment device comprises at least one electrode configured to come into electrically conductive contact with a skin of a user. The skin treatment device comprises a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the at least one electrode such that a radio frequency electromagnetic energy is applied to the skin. The skin treatment device comprises a first temperature sensor configured to measure a first temperature of the skin. The skin treatment device comprises a second temperature sensor configured to measure a second temperature of the skin, the first temperature sensor and the second temperature sensor being spaced apart such that the first temperature of the skin is measured at a spaced apart location from a location at which the second temperature of the skin is measured. The skin treatment device comprises at least one processor in operable communication with the radio frequency electromagnetic signal generator, wherein the at least one processor is configured to execute program instructions, and wherein the program instructions are configured to cause the at least one processor to control the radio frequency electromagnetic signal generator such that the radio frequency electromagnetic energy applied to the skin is stopped if a temperature difference between the first temperature and the second temperature exceeds a predetermined temperature difference threshold.

[0044] In embodiments, the program instructions are configured to cause the at least one processor to control the radio frequency electromagnetic signal generator such that the radio frequency electromagnetic energy applied to the skin is stopped if both: i) a temperature difference between the first temperature and the second temperature exceeds a predetermined temperature difference threshold; and ii) temperature difference exceeds the predetermined temperature difference threshold for more than a predetermined time threshold.

[0045] In embodiments, the predetermined temperature difference threshold is approximately 1 to approximately 5 degrees, optionally, approximately 2 to approximately 4 degrees, and further optionally approximately 3 degrees, and / or wherein the predetermined time threshold is approximately 3 to approximately 7 seconds, optionally, approximately 4 to approximately 6 seconds, and further optionally approximately 5 seconds.

[0046] In embodiments, the first temperature sensor and the second temperature sensor are independent from each other.

[0047] In embodiments, the first temperature sensor and the second temperature sensor are connected to different microcontroller unit (MCU) channels.

[0048] In yet another aspect, there is provided a method of controlling a skin treatment device. The method comprising supplying a radio frequency electromagnetic signal to at least one electrode of the skin treatment device. The method comprising receiving a temperature measurement. The method comprising varying a power of the radio frequency electromagnetic energy based on the measured temperature according to a powertemperature relationship.

[0049] In embodiments, the method comprises receiving an impedance measurement. The method comprises varying a voltage of the radio frequency electromagnetic signal based on the measured impedance according to a voltage-impedance relationship thereby varying the power of the radio frequency electromagnetic energy.

[0050] BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0052] Fig. 1A shows a skin treatment device in accordance with an embodiment of the present disclosure;

[0053] Fig. IB is a focused view of the messaging arms of the device of Fig. 1 A, in which temperature sensors are visible;

[0054] Fig- 2 is a block diagram of an electrical system of the skin treatment device 10 of Fig. 1A;

[0055] Fig. 3 shows a flow chart showing operation of the skin treatment device of Fig. 1A in accordance with an embodiment of the present disclosure;

[0056] Fig. 4 shows an exemplary power-temperature relationship used in the operation of the skin treatment device of Fig. 1A;

[0057] Fig. 5 shows an exemplary voltage-impedance relationship used in the operation of the skin treatment device of Fig. 1; and

[0058] Fig. 6 shows a skin treatment device having stationary arms, in accordance with another embodiment of the present disclosure. DETAILED DESCRIPTION OF EMBODIMENTS

[0059] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the disclosure. However, it will be understood by those of ordinary skill in the art that the disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, components, modules, units and / or circuits have not been described in detail so as not to obscure the disclosure.

[0060] In accordance with embodiments of the present disclosure, a skin treatment device includes two or more radiofrequency (RF) electrodes. Each radiofrequency electrode is incorporated in a massaging arm. One or more of the massaging arms is movable, for example with a back-and-forth motion, lateral motion, a circular motion and / or a vibratory motion. Alternatively, in some embodiments, one or more arms of the device are stationary.

[0061] Even though the figures refer to a skin treatment device with one or more massaging arms, any massaging arms referred to herein are purely optional. In other words, the skin treatment device may not comprise any massaging functions / massaging arms.

[0062] The skin treatment device may include a mechanism for coordinated movement of two or more of the massaging arms. For example, the coordinated movement may enable distal ends of two massaging arms to alternately approach and recede from one another. The motion may be repetitive or periodic.

[0063] A frequency or speed of the motion of a massaging arm may be adjustable. Similarly, a distance through which a massaging arm is moved during the course of the motion (e.g. amplitude of the motion) may be adjustable.

[0064] Alternatively to coordinated motion of two or more massaging arms, one massaging arm may be moved relative to one or more stationary neighboring massaging arms. Reference herein to motion of massaging arms should be understood as referring to motion of the massaging arms relative to one another, regardless of how many of the massaging arms are moved relative to the remainder of the skin treatment device.

[0065] The skin treatment device includes electronic circuitry for applying a radiofrequency electromagnetic signal to a radiofrequency electrode that is incorporated into each massaging arm. For example, radiofrequency electromagnetic signals of opposite polarity may be applied concurrently to two (or more) of the massaging arms. A frequency or amplitude (and thus a power) of the radiofrequency signal may be adjustable, as described below. Optionally, the frequency, amplitude, or another characteristic of the radiofrequency signal may be generated so as to change in a periodic manner. For example, a variation of a characteristic of a radiofrequency signal that is applied to a massaging arm may be coordinated with motion of the massaging arm.

[0066] In some embodiments, the user selects (such as via the device user interface) one or both of: an energy level to be applied, the extent and / or speed of movement of the massaging arms.

[0067] A skin treatment device in accordance with embodiments of the present disclosure may be portable. For example, components of the skin treatment device may be contained within a single housing. The housing may be of such a size as to enable the skin treatment device to be held in one hand. The skin treatment device may be shaped so as to be securely and comfortably held in the hand. Optionally, the skin treatment device may be battery powered. Optionally, the skin treatment device is rechargeable.

[0068] A skin treatment device in accordance with embodiments of the present disclosure may be placed in contact with skin and operated. For example, a user of the device may hold the skin treatment device such that the massaging arms are placed in contact with the user's own skin, or with the skin of another person whose skin is being treated by the user. Operation of the skin treatment device may include moving the massaging arms while concurrently applying a radiofrequency electromagnetic signal to the massaging arms.

[0069] Mechanical movement of the massaging arms may massage the skin to which the skin treatment device is applied. For example, the massaging arms may move in a periodic back-and-forth motion toward and away from each other. The periodic back-and-forth motion may then alternately squeeze (pinch) and stretch the skin that is between the massaging arms. Movement of the massaging arms may be configured so as to assure that the resulting massaging is enjoyable or tolerable, without causing any pain or discomfort (e.g. by applying an excessive force to the skin). The user may manually adjust the force with which the skin treatment device is pressed against the skin being treated.

[0070] Concurrent application of the radiofrequency electromagnetic signal to the skin may cause a radiofrequency electrical current to flow through the skin. The flow of radiofrequency electrical current through the skin may then heat the skin (electrothermolysis of the skin).

[0071] The depth at which a radiofrequency electrical current flows below the outer surface of the skin may be determined by one or more factors. The factors may include, for example, the frequency of the applied radiofrequency electromagnetic signal, the temperature of the skin, the conductivity of the skin, and a separation distance between the electrodes (each electrode at a distal end of one of the massaging arms, or being identical with an outer surface of a massaging arm) through which the radiofrequency electromagnetic signal is applied to the skin. A motion of the massaging arms in which the distal ends of two massaging arms alternately approach and retreat from one another causes the separation distance between the electrodes to increase and decrease during the motion. The increase and decrease of the separation distance may thus vary the depth of radiofrequency electrical current, and thus of heating (electro-thermolysis), within the skin. Thus, the application of a radiofrequency electromagnetic signal to the skin concurrently with a back-and-forth motion of the electrodes may enable repetitive heating of layers within the skin at a range of depths.

[0072] One or more of the massaging arms may be provided with a temperature sensor. The temperature sensor may be placed in thermal contact with the skin when the skin treatment device or the massaging arms of the skin treatment device are placed in contact with the skin. The temperature sensor may generate a voltage or other electrical signal that is indicative of a measured temperature of the skin. In some embodiments, each of the massaging arms may be provided with a temperature sensor. Each of the temperature sensors senses the temperature of the skin at the corresponding point of contact of the massaging arm with the skin, simultaneously when the massaging arm conducts radiofrequency electromagnetic signal to the point of contact.

[0073] Circuitry or a controller for controlling generation of the radiofrequency electromagnetic signal may be coupled to the temperature sensor. The circuitry may be configured such that radiofrequency electromagnetic signal is controlled based on the temperature measured by the temperature sensor.

[0074] A skin treatment device in accordance with embodiments of the present disclosure may be configured for home use or for use by a nonprofessional user. In certain embodiments, the skin treatment device in accordance with embodiments of the present disclosure may be configured for professional use by a professional user. For example, the skin treatment device may be sufficiently small so to enable storage of the skin treatment device in a similar manner to other home cosmetic or beauty products and devices. Also, a small size and an ergonomic shape of the skin treatment device may enable the skin treatment device to be handled and operated without the assistance of any fixtures or other support structure. The skin treatment device may include built-in safety features that enable safe operation by a nonprofessional user. In accordance with some of the embodiments, the device includes a flexible sleeve to prevent exposure of the skin to the circuitry of the device. The flexible sleeve seals a space between the arms and the housing, and receives the pinched skin within a depression thereof to avoid contact of the pinched skin with any of the internal components of the device, while not interfering the movement of the massaging arms. Thus, rendering the device suitable for a safe and secure use by a nonprofessional user.

[0075] Treatment of skin using a skin treatment device in accordance with embodiments of the present disclosure may be advantageous. A skin treatment device as described herein may provide safe and efficient heating of the skin.

[0076] Fig. 1 A shows a skin treatment device 10 in accordance with an embodiment of the present disclosure.

[0077] Skin treatment device 10 comprises a housing 11. Housing 11 may be configured with an ergonomic shape so as to enable skin treatment device 10 to be held in a single hand by a user. The shape of housing 11 may be configured so as to enable holding or pressing of massaging arms 12 against the skin to be treated. The shape of housing 11 may also enable convenient and effective manipulation of skin treatment device 10. Housing 11 may include a rigid electrically insulating material (e.g. plastic) so as to electrically and mechanically isolate a user of skin treatment device 10 from any internal electrical or mechanical components of skin treatment device 10. Housing 11 may be designed to isolate internal components of skin treatment device 10 from environmental factors (e.g. moisture or corrosive materials) that may adversely affect operation of the internal components.

[0078] Massaging arms 12 extend from an end of skin treatment device 10 that is configured to be placed against the skin to be treated. Massaging arms 12 are configured to move in a coordinated motion alternately toward and away from one another. Thus, when placed against skin, the coordinated motion of massaging arms 12 may result in a gentle pinching and releasing of a region of skin between massaging arms 12. Thus, the skin may be massaged by the motion of massaging arms 12. It is contemplated that any other motion of massaging arms 12 may be used (e.g. a random relative motion) with the present disclosure, as would be understood by those skilled in the art.

[0079] Each massaging arm 12 may be contoured (e.g. without sharp edges or corners) so as to prevent scratching of the skin or to slip over the skin. A surface of the massaging arm 12 may be ridged, embossed, pitted, or otherwise patterned so as to facilitate grabbing or gripping the skin.

[0080] A material for an outer surface of each massaging arm 12 may be selected so as to avoid irritation or chafing of the skin. Prior to or during use, a lubricating fluid, gel, or cream may be applied to each massaging arm 12 and / or to the skin of the user. The lubricating fluid, gel, or cream may be electrically conductive.

[0081] Flexible sleeve 13 of the device 10 may be made of a flexible material, such as flexible plastic or rubber. The flexibility of flexible sleeve 13 may enable housing 11 to remain sealed, while still enabling motion of massaging arms 12.

[0082] In the illustrated embodiment, skin treatment device 10 includes two massaging arms 12. In other embodiments, more than two massaging arms may be included. For example, a plurality of massaging arms may be arranged in cooperating pairs. The massaging arms of each cooperating pair may move in a coordinated motion. In other embodiments, three or more massaging arms may be placed in a single row and caused to move with a coordinated motion. For example, a massaging arm that is located between two neighboring massaging arms may alternately move toward one of the neighboring massaging arms and then toward the other. The neighboring massaging arms may be stationary or moveable. In other embodiments, a single massaging arm may be used, for example, with a rotating motion, a vibratory motion, or other suitable motion for massaging the tissue.

[0083] Part or all of an outer surface of each massaging arm 12 may include, or may be made of, an electrically conducting material. For example, the conducting material may include a metal, a conducting plastic, or another conducting material suitable for inclusion in an outer surface of massaging arm 12. The conducting material acts as an electrode which may facilitate electrical coupling of the massaging arm 12 to the skin to be treated.

[0084] Skin treatment device 10 may include a user interface 14. The user interface may include one or more controls. For example, controls may include one or more pushbuttons (as shown), switches, levers, dial wheels, or knobs. A user may operate a control so as to control operation of skin treatment device 10. For example, operation of a control may cause skin treatment device 10 to be powered on or off, set a treatment power, or to enter a standby status. Operation of user interface 14 may indicate selection of a mode of operation of skin treatment device 10.

[0085] Operation of the user interface 14 may start or stop motion of massaging arms 12. Operation of user interface 14 may change or select a speed, distance (e.g. amplitude) or other characteristic of the motion. For example, operation of user interface 14 in the form of a pushbutton may change a state of motion of massaging arms 12 from one state to a successive state in accordance with a predetermined sequence of states. As another example, user interface 14 may be operated to select a characteristic of the motion from among a set of predetermined characteristics.

[0086] Operation of user interface 14 may initiate or stop generation of a radiofrequency electromagnetic signal for conduction into the skin by massaging arms 12. Operation of user interface 14 may cause resumption of generation of radiofrequency electromagnetic signal after an interruption, e.g. as caused in response to a detected high skin temperature (described below). Operation of user interface 14 may change a frequency, amplitude, or other characteristic of a radiofrequency electromagnetic signal that is applied to massaging arms 12. For example, successive operation of a control of user interface 14 may cause the set power of the radiofrequency electromagnetic signal to change in accordance with a predetermined sequence of signal characteristics.

[0087] User interface 14 may include one or more indicators 16. For example, an indicator 16 may include a light-emitting or other visible indication of a status of skin treatment device 10. Indicator 16 may include a light emitting diode (LED), light bulb, or other light generating device placed on or near the surface of skin treatment device 10 or housing 11 (e.g. protected by or enclosed in a transparent or translucent window, dome, or casing). Indicator 16 may include a light emitting device (e.g. light bulb or LED) that is located interior to skin treatment device 10, with its light being channeled to an outer surface of skin treatment device 10 or housing 11 (e.g. by an optical fiber or other light guide). For example, one or more indicators 16 may indicate a power state of skin treatment device 10 (e.g. power on, power off, standby).

[0088] One or more indicators 16 may indicate a current motion state of massaging arms 12. A motion state may include, for example, the motion being on or off, a speed, amplitude, or other characteristic of motion, or a currently selected motion state from among a limited set of predetermined motion states.

[0089] One or more indicators 16 may indicate a current state of a radiofrequency electromagnetic signal motion that is currently applied by massaging arms 12. A state of an applied radiofrequency electromagnetic signal may include, for example, whether signal generation is currently turned on or off, a frequency, amplitude, or other characteristic of the signal, or whether current generation has been interrupted (e.g. due to detected high skin temperature).

[0090] In addition to, or in place of, a visible indication, skin treatment device 10 may be configured to generate an audible signal to indicate a current state of, or a change in a current state of, skin treatment device 10.

[0091] Skin treatment device 10 may include one or more connectors 18. A connector 18 may be configured to connect to a corresponding connector of an appropriate cable.

[0092] For example, a connector 18 may be configured to enable connection of skin treatment device 10 to an external power source (e.g. electric mains or power grid, or a power adapter, converter, or transformer) via an appropriate power cable. In accordance with some embodiments of a skin treatment device 10, skin treatment device 10 may incorporate an internal power source. For example an internal power source may include a replaceable or rechargeable battery or cell. A rechargeable battery may be recharged by connecting an appropriate connector 18 to an external power source. In other embodiments, power to operate skin treatment device 10 is provided solely by an external power source that is connected to a connector 18.

[0093] A connector 18 may be configured to connect an incorporated processor of skin treatment device 10 to a data port of an external computer, controller, or other device. Such a data connection may enable, for example, configuration of skin treatment device 10. In such a case, parameters for operation of skin treatment device 10 may be set or modified by a user or external device. In this manner, a skin treatment device 10 may be configured in accordance with, e.g., preferences of a user, or in accordance with changing manufacturer's recommendations (e.g. particular motion protocols for motion of massaging arms 12, or for generation of particular radiofrequency electromagnetic signals). Such a data connection may also facilitate diagnosis of problems with operation of a skin treatment device 10.

[0094] In Fig. IB, is a focused view of the messaging arms of the device of Fig. 1A, in which temperature sensors are visible. As shown, a temperature sensor 30 can be mounted on each of the massaging arms 12, for sensing the temperature of the skin being contacted by the arm. Some embodiments can include more than one sensor per each arm.

[0095] In some embodiments, during the massaging motion, the arm is moved over a relatively small surface area of the skin, in which it assumed that the skin is evenly heated by the RF energy. In addition, the measurement can take into account a thermal mass of the arm itself, which for example can cause a certain time difference between the actual skin temperature and the measured skin temperature.

[0096] Fig- 2 is a block diagram of an electrical system 20 for operation of a skin treatment device 10 in accordance with embodiments of the present disclosure.

[0097] Electrical system 20 may include a controller 40 for controlling operation of skin treatment device 10. Controller 40 may represent a unit, or a plurality of intercommunicating units, that is configured to coordinate among various components of electrical system 20. Controller 40 may include / consist of one or more processors that are configured to operate in accordance with programmed instructions. In another example, controller 40 may include circuitry (e.g. in the form of an integrated control circuit) that is configured to operate components of skin treatment device 10.

[0098] Controller 40 may communicate with a data storage unit 42. Data storage unit 42 may include one or more volatile or non-volatile data storage devices, or may represent a data storage function of a device. For example, data storage unit 42 may include a nonvolatile data storage device for storing programmed instructions or data for operation of a skin treatment device 10 in accordance with some embodiments of the present disclosure. Data storage unit 42 may be used to store data that is generated during operation of the skin treatment device 10 by a controller 40 in the form of a processor.

[0099] Controller 40 may be configured to detect operation of user interface 14. Controller 40 may operate in accordance with a detected operation of one or more controls of user interface 14 by a user.

[0100] Controller 40 may be configured to operate one or more indicators 16. For example, an indicator 16 may be operated to indicate a current state or status of operation of controller 40 or a component of electrical system 20.

[0101] Controller 40 may communicate with components and circuitry for generating a radiofrequency electromagnetic signal. Specifically, the controller 40 may control radio frequency electromagnetic signal generator 44. The radio frequency electromagnetic signal generator 44 is configured to supply a radio frequency electromagnetic signal to the electrodes 45 such that a radio frequency electromagnetic energy is applied to the skin. Radio frequency electromagnetic signal generator 44 may represent one or more components or modules of controller 40, may include components that are separate from controller 40, or both. A radiofrequency electromagnetic signal that is generated by radio frequency electromagnetic signal generator 44 may be conducted to one or more massaging arms 12 and ultimately to the electrodes 45 on each of the massaging arms 12 so as to induce a radiofrequency electrical current to flow in skin that is in contact with electrodes 45.

[0102] Controller 40 and / or radio frequency electromagnetic signal generator 44 may be configured to measure the impedance between the electrodes 45, as would be understood by those skilled in the art. Accordingly, the electrodes 45 may be used, during operation, to measure the impedance of the skin between the electrodes 45. The impedance measurements may be used in real time to control the radio frequency electromagnetic signal generator 44 to select a particular radiofrequency electromagnetic signal (e.g. by altering the voltage of the signal).

[0103] In summary, controller 40 may control radio frequency electromagnetic signal generator 44 to select a radiofrequency electromagnetic signal on the basis of operation by a user of a user interface 14, measurements from the temperature sensor(s) 30, measurements of the impedance between electrodes 45, the program instructions stored on data storage 42 and any other measurements carried out by the skin treatment device 10.

[0104] Controller 40 may communicate with components and circuitry for controlling motion of moving components, such as massaging arms 12. Motion controller 48 may be configured to operate motor 22. For example, motion controller 48 may be configured to adjust an electrical current that is provided to drive motor 22 so as to operate drive motor 22 at a particular speed. Operation of drive motor 22 may cause massaging arms 12 to move in a predetermined manner.

[0105] Motion controller 48 may be configured to monitor an electrical current that is supplied to drive motor 22. For example, monitoring a current that is supplied to drive motor 22 may enable detecting a state where motion of a massaging arm 12 is impeded or obstructed.

[0106] Electrical system 20 may include a power supply 50. Power supply 50 may provide power for operation of controller 40 or for operation of another component of electrical system 20. Power supply 50 may include a replaceable or rechargeable power source, such as a replaceable or rechargeable battery or cell. Power supply 50 may connect to an external power source, such as an electric power grid, generator, or power supply device, via connector 18. Power supply 50 may include an appropriate converter or transformer for converting an input electrical current from connector 18 to a current that is usable in operating one or more components of the skin treatment device.

[0107] Electrical system 20 may connect to or communicate with the one or more temperature sensors 30. A temperature sensor 30 may be mounted on a massaging arm 12. Temperature sensor 30 may be embedded within, or may be in thermal contact with, a massaging arm 12. In some embodiments, a temperature sensor 30 may be provided in each of the massaging arms 12. Optionally, the temperature sensor is embedded, at least in part, in the RF electrode.

[0108] Each temperature sensor 30 may sense the temperature of the skin at the respective contact point of the corresponding massaging arm 12 with the skin. Thus, the temperature sensor 30 is configured to sense the temperature of the skin at the point of contact where the electromagnetic radio frequency signal is provided to the skin, thereby ensuring better accuracy in sensing temperature of the skin at the contact points receiving the electromagnetic radio frequency signal, and more efficient and effective operation of the device.

[0109] Fig. 3 shows a flow chart showing operation 100 of the skin treatment device 10 in accordance with an embodiment of the present disclosure.

[0110] At step 110 the skin treatment device 10 is turned on by a user. At this step, the user may use user interface 14 to set various user settings for the skin treatment device 10, as described above.

[0111] Once skin treatment device 10 is in operation, a measurement of the impedance between electrodes 45 is carried out. For example, if the electrodes 45 are in contact with skin, the impedance of the skin between the electrodes is measured. This step is optional and in alternative embodiments the method moves on to step 130 without an impedance measurement.

[0112] At step 130, the skin treatment device 10 uses temperature sensor(s) 30 to measure the temperature of the skin. For example, the skin treatment device may use at least two temperature sensors being spaced apart such that a first temperature of the skin is measured at a spaced apart location from a location at which a second temperature of the skin is measured. In the example in which each massaging arm includes a temperature sensor, the space between the temperature sensors corresponds to the space between the massaging arms. In some examples, such space can range between 14- 22 mm, 5-15 mm, 10-30 mm or intermediate, larger or smaller space.

[0113] At step 140, the controller 40 controls the radio frequency electromagnetic signal generator 44 to vary a power of the radio frequency electromagnetic energy applied to the skin based on the measured temperature(s) of the skin according to a power-temperature relationship so as to maintain a target temperature of the skin, as explained in detail below. As used herein, the power of the radio frequency electromagnetic energy applied to the skin may refer to a (desired) power received / absorbed by the skin (e.g. in the form of heat energy). The power intended to be absorbed by the skin can be varied by changing the form of the radio frequency electromagnetic signal applied between the electrodes 45. For example, the voltage, frequency and / or duty cycle of the radio frequency electromagnetic signal may be varied so as to vary the power of the radio frequency electromagnetic energy applied to the skin. As described in further detail below, in certain embodiments, the voltage of the radio frequency electromagnetic signal is varied in view of a measured impedance of the skin so as to vary the power of the radio frequency electromagnetic energy applied to the skin. In such embodiments, a more accurate application of the desired power levels may be achieved, irrespective of the skin composition.

[0114] At optional step 150, the user settings are checked again to see if any new settings have been selected by the user using user interface 14. If the user settings are such that treatment is to continue, the method moves to step 160 which is a pause. The pause may be any duration of time, for example, 0.1 seconds to 1 second. Thereafter, the method loops back to step 120. The pause 160 is optional and the method may instead immediately loop back to step 120.

[0115] If at step 150 the user settings have been selected to end the treatment, the method moves on to step 170 in which the controller 40 controls the radio frequency electromagnetic signal generator 44 to turn off the radio frequency electromagnetic energy applied to the skin. The method moves on to step 180 in which that particular treatment finishes. From this state, the user may select another treatment using the user interface 14 or power off the device entirely (e.g. by removing the mains power).

[0116] Further details of step 140 are now provided. Generally, the skin treatment device 10 is configured to vary the power of the radio frequency electromagnetic energy applied to the skin based on the measured temperature of the skin according to a power-temperature relationship, thereby maintaining a target temperature of the skin. This provides for accurate heating of the skin within strict limits and therefore improves the safety and efficacy of the treatment.

[0117] The power-temperature relationship may be predefined and stored on data storage 42 for the controller 40 to access. The power-temperature relationship may take the measured temperature(s) from temperature sensor(s) 30 as an input and provide a power as an output. The power-temperature relationship may additionally or alternatively take one or more temperature variation metric as input and provide a power as output. The one or more variation metric may include a combined measured temperature that may be defined as an average of the first and second temperatures and / or a difference between the first and second temperatures. The power provided by the power-temperature relationship may be the power that should be applied to the skin via the radio frequency electromagnetic energy. The power-temperature relationship may be defined in many different forms, for example, a mathematical equation (or a plurality of mathematical equations) and / or a table containing a plurality of linked powers and temperatures.

[0118] An exemplary power-temperature relationship is explained in relation to Fig. 4. The measured temperature T is provided as the independent variable and the power P is provided as the dependent variable of the graph. The power-temperature relationship is defined so as to maintain a target temperature TT of the skin.

[0119] As can be seen in Fig. 4, if the measured temperature T is less than or equal to a base low temperature TL, the power P is set to a maximum set power PM. The maximum set power PM may be set directly by the user using the user interface 14 or may be predetermined and fixed. In this manner, the skin treatment device 10 may quickly heat the skin to a temperature where treatment becomes effective. This may improve the efficiency of the treatment.

[0120] The maximum set power PM may be between approximately 2 W and approximately 8 W, optionally, between approximately 3 W and approximately 7 W, and further optionally, between approximately 4 W and approximately 6 W.

[0121] If the measured temperature T is greater than the base low temperature TL and lower than the target temperature TT, then the power P is varied linearly with respect to the difference between the target temperature TT and the measured temperature T. In other words, if the measured temperature T is greater than the base low temperature TL and lower than the target temperature TT, then the power P = -kT + c (where k and c are positive constants). This may provide for greater control of the skin temperature and reduces the chances of the skin temperature overshooting the target temperature TT. By gradually reducing the power when the measured temperature T is within the range of TL and TT , the target temperature TT can be reached more precisely. Such control can be implemented at the initial obtaining of the target temperature as well as at any time in which the temperature drops, even if only by a small extent, from the target temperature.

[0122] If the measured temperature T is equal to the target temperature TT the power is set to a holding power PH. The holding power PH may be non-zero. The holding power PH may be sufficient to maintain a steady skin temperature of TT. In certain embodiments, the holding power PH may be between approximately 250 mW and approximately 350 mW, optionally, between approximately 275 mW and approximately 325 mW, and further optionally, approximately 300 mW.

[0123] If the measured temperature T is greater than the target temperature TT the power P decreases. As shown in Fig. 4, the power P is varied inversely proportionally with respect to the difference between the target temperature TT and the measured temperature T.

[0124] If the measured temperature T is greater than or equal to a critical high temperature Tc, the power P is zero (i.e. the radio frequency electromagnetic energy applied to the skin is stopped).

[0125] In certain embodiments, if the measured temperature T is greater than the target temperature TT but below the critical high temperature Tc, the power P is non-zero. This may prevent the skin from becoming too cold once the target temperature TT is achieved.

[0126] Fig. 4 is exemplary in nature and various alterations may be made. For example, in alternative embodiments, if the measured temperature T is greater than the base low temperature TL and lower than the target temperature TT, then the power P is varied inversely proportionally with respect to the difference between the target temperature TT and the measured temperature T.

[0127] In some embodiments, the power-temperature relationship may include a first variation portion where the measured temperature(s) (or a function indicative thereof, e.g. an average of the measured temperatures) is between the base low temperature and the target temperature and a second variation portion where the measured temperature(s) (or a function indicative thereof, e.g. an average of the measured temperatures) is between the target temperature and the critical high temperature, wherein the power varies with respect to the measured temperature(s) (or a function indicative thereof) in the first and second variation portions according to different power-temperature relationships. In the first portion, the variation of the power with respect to the measured temperature(s) (or a function indicative thereof) may be proportional (or in other embodiments, inversely proportional) to the difference between the measured temperature(s) (or a function thereof) and the base low temperature. In the second portion, the variation of the power with respect to the measured temperature(s) (or a function indicative thereof) may be inversely proportional (or in other embodiments inversely proportional) to the difference between the measured temperature(s) (or a function indicative thereof) and the target temperature. In step 140, once the desired power according to the output of the powertemperature relationship is determined, the controller 40 sets the voltage (i.e. amplitude) of the radio frequency electromagnetic signal applied by the radio frequency electromagnetic signal generator 44 so as to achieve this desired power level.

[0128] The impedance of the skin as measured in step 120 may be used to calculate the voltage required to achieve the desired power. For example, the voltage may be calculated according to the equation:

[0129] Vvrms = V vp i . i I where Vrms is the root mean square voltage, I is the impedance and P is the desired power. By using the measurement of the impedance of the skin, the correct power can be applied to the skin, regardless of skin composition, improving the safety and efficacy of the treatment.

[0130] An exemplary voltage-impedance relationship is explained in relation to Fig. 5. The measured impedance I is provided as the independent variable and the Vrms2is provided as the dependent variable of the graph. The voltage-impedance relationship is defined so as to maintain the desired power of radio frequency electromagnetic energy applied to the skin (as determined by the power-temperature relationship described above), irrespective skin composition / type.

[0131] As can be seen in Fig. 5, during operation of the skin treatment device 100, the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is below a critical low impedance II or above a critical high impedance IH. This is used as a safety feature to avoid applying radio frequency electromagnetic energy unless it is in contact with skin.

[0132] In certain embodiments, the critical low impedance II is between approximately 100 ohms to 150 ohms, optionally between approximately 110 ohms to 140 ohms, and further optionally, between approximately 120 ohms to 130 ohms.

[0133] In certain embodiments, the critical high impedance IH is between approximately 250 ohms to 300 ohms, optionally between approximately 260 ohms to 290 ohms, and further optionally, between approximately 270 ohms to 280 ohms. In certain embodiments, the skin treatment device 10 may be configured to start applying radio frequency electromagnetic energy automatically upon detection of skin (e.g. when the measured impedance is between the critical low impedance II and the critical high impedance IH).

[0134] In some embodiments, the impedance of the skin is measured continuously, and the voltage is iteratively adjusted in response to the sensed impedance so as to reach a desired power level.

[0135] In certain implementations, two or more temperature sensors 30 may be used. For example, a temperature sensor may be provided on each massaging arm 12. In certain embodiments, the two or more temperature sensors are spaced apart such that the respective measurements of the temperature are at spaced apart locations of the skin. Use of two spaced-apart temperature sensors ensures that the temperature of the skin is monitored at distinct locations meaning that any hot spots are detected.

[0136] In such implementations, the method 100 may optionally be altered to include an override routine such that if a temperature difference between the two or more temperature sensors exceeds a predetermined temperature difference threshold, the radio frequency electromagnetic energy applied to the skin is stopped. A temperature difference exceeding a temperature difference threshold may imply that the skin is being heated unevenly (which may be a safety issue) and / or incorrect function of the skin treatment device 10. The predetermined temperature difference threshold may be approximately 1 to approximately

[0137] 5 degrees, optionally, approximately 2 to approximately 4 degrees, and further optionally approximately 3 degrees.

[0138] In certain embodiments, the radio frequency electromagnetic energy applied to the skin is stopped only if the temperature difference exceeds the temperature difference threshold for a certain predetermined time threshold. The predetermined time threshold is approximately 3 to approximately 7 seconds, optionally, approximately 4 to approximately

[0139] 6 seconds, and further optionally approximately 5 seconds.

[0140] Use of a minimum time threshold before stopping the radio frequency electromagnetic energy may mean that temporary fluctuations of skin temperatures are tolerated within certain predetermined limits. In certain embodiments, if any of the two or more temperature sensors 30 measure a temperature over the critical high temperature Tc, radio frequency electromagnetic energy applied to the skin is stopped immediately. This provides a safety mechanism for the skin treatment device 10.

[0141] Throughout this disclosure, if the skin treatment device 10 includes two or more temperature sensors 30, the term “measured temperature” referred to herein may be an average of the respective measured temperature of the two or more sensors, or any other combined function thereof (for example, a weighted average of the respective measured temperature of the two or more sensors). In some embodiments, a temperature of a single sensor which is used for the calculation of the average (or other combined function) of the multiple sensors is a temperature measured at a selected (e.g. predetermined) time point. Alternatively, the temperature of a sensor which is used of the calculation includes an average (or any other suitable function) of temperatures measured by the specific single sensor over time.

[0142] Whilst the exemplary embodiment has been presented with massaging arms, the massaging arms are optional and may be removed. In other words, the skin treatment device may comprise no massaging function / massaging arms. In such instances, the one or more electrodes may be placed on the body of the device so as to come into contact with the skin of a user. An example of a device having stationary arms which are shaped and configured to come into contact with the skin is shown in Fig. 6. Device 60 is, in some embodiments, a hand held device, having an elongated body 62 and a head 64 at a distal end of the body. A plurality of stationary arms 66, for example 4 arms as shown (other embodiments may include a different number of arms) extend distally from the head for contacting the skin of the user. An RF electrode can be incorporated in each of the arms. One or more temperature sensors can be incorporated in the arms, for example, one temperature sensor per each arm. In the example shown, the temperature sensors are not visible as they are embedded inside the arm itself, with the outer surface of the arm being thin enough, at least at a position of the temperature sensor, to enable the sensor to detect a temperature of the skin or at least a temperature which is indicative of the temperature of the skin. Further, in some embodiments the arm can be constructed of a heat-conductive material, e.g. metal, which effectively functions as a surface of the temperature sensor (which is embedded within the arm). In other examples, for example as of the device of FIG. 1A, the arm can be constructed of a plastic or other insulating material, in which case the temperature sensor should be located on an exposed, external surface of the arm.

[0143] In use, the user holds the device to bring the distal ends of the arms into contact with the skin, and may move the device over the skin to treat additional locations. Therefore, although the arms themselves are static, movement of the device as a whole moves the arms across a surface of the skin.

[0144] The circuitry, operation and control of the device of Fig. 6 may be for example as described above, whereby aspects related to the motion of the arms do not apply to Fig. 6.

[0145] While two exemplary embodiments have been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist.

[0146] For example, , in alternative embodiments, a single (e.g. rotating) massaging arm may be used. In such embodiments, the second electrode may be placed on the skin of a user at a fixed location (e.g. using an adhesive conducive pad).

[0147] It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.

Claims

CLAIMS:

1. A skin treatment device, comprising:(a) at least one electrode configured to come into electrically conductive contact with a skin of a user;(b) a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the at least one electrode such that a radio frequency electromagnetic energy is applied to the skin;(c) a first temperature sensor configured to measure a first temperature of the skin;(d) a second temperature sensor configured to measure a second temperature of the skin, the first temperature sensor and the second temperature sensor being spaced apart such that the first temperature of the skin is measured at a spaced apart location from a location at which the second temperature of the skin is measured; and(e) at least one processor in operable communication with the radio frequency electromagnetic signal generator, wherein the at least one processor is configured to execute program instructions, wherein the program instructions are configured to cause the at least one processor to control the radio frequency electromagnetic signal generator to vary a power of the radio frequency electromagnetic energy applied to the skin according to a power-temperature relationship so as to maintain a target temperature of the skin, and wherein the power-temperature relationship is defined to use as input one or more temperature variation metric, the temperature variation metric including a combined measured temperature which is a function of the first temperature and the second temperature; wherein if said combined measured temperature is above a base low temperature and below the target temperature, the powertemperature relationship is such that the radio frequency electromagnetic signal generator progressively decreases the power as the combined measured temperature gets closer to the target temperature of the skin.

2. The skin treatment device of Claim 1 , wherein the combined measured temperature is an average of the first temperature and the second temperature.

3. The skin treatment device of Claim 1 or Claim 2, wherein, if the combined measured temperature is below the target temperature, the power-temperature relationship is such that the power is varied linearly or inversely proportionally with respect to the difference between the target temperature and the combined measured temperature.

4. The skin treatment device of any one of the preceding claims, wherein the powertemperature relationship is such that the power is non-zero when the combined measured temperature is between a target temperature of the skin and a critical high temperature of the skin.

5. The skin treatment device of any one of the preceding claims, wherein the powertemperature relationship is such that the power is non-zero when the combined measured temperature is equal to the target temperature.

6. The skin treatment device of any one of the preceding claims, wherein, if the combined measured temperature is above the target temperature and below a critical high temperature, the power-temperature relationship is such that the power is decreased inversely proportionally with respect to the difference between the target temperature and the combined measured temperature.

7. The skin treatment device of any one of the preceding claims, wherein the powertemperature relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the first temperature, the second temperature, an average or some other combined function thereof exceeds a critical high temperature of the skin.

8. The skin treatment device of any one of the preceding claims, wherein the powertemperature relationship is such that the power of the radio frequency electromagneticenergy applied to the skin is a maximum set power when the combined measured temperature is below the base low temperature.

9. The skin treatment device of Claim 8, further comprising a user interface, and wherein the user interface is configured such that the maximum set power can be set by the user through the user interface.

10. The skin treatment device of any one of the preceding claims, wherein the powertemperature relationship is such that:(a) the power is a maximum set power when the combined measured temperature is below a base low temperature;(b) the power is varied inversely proportional to the difference between the target temperature and the combined measured temperature when the combined measured temperature is greater than the base low temperature and below the target temperature; and(c) the power is stopped if the combined measured temperature exceeds a critical high temperature.

11. The skin treatment device of any one of the preceding claims, wherein the one or more temperature variation metric includes a temperature difference between the first temperature and the second temperature and the power-temperature relationship is such that the radio frequency electromagnetic signal generator varies the power when said temperature difference exceeds a predetermined threshold.

12. The skin treatment device of claim 11, wherein the power-temperature relationship is such that the radio frequency electromagnetic signal generator stops the power when said temperature difference exceeds the predetermined temperature threshold.

13. The skin treatment device of Claim 11, wherein the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic energy applied to the skin is stopped if the temperature difference betweenthe first temperature and the second temperature exceeds a predetermined temperature difference threshold for more than a predetermined time threshold.

14. The skin treatment device of any one of the preceding claims, wherein the first temperature sensor and the second temperature sensor are independent from each other, and, optionally, wherein the first temperature sensor and the second temperature sensor are connected to different microcontroller unit (MCU) channels.

15. The skin treatment device of any one of the preceding claims, wherein the at least one electrode constitutes at least one first electrode and at least one second electrode; wherein the processor is configured to control the radio frequency electromagnetic signal generator to vary a voltage of the radio frequency electromagnetic signal based on an impedance of the skin according to a voltage-impedance relationship, the impedance of the skin being measured between the at least one first electrode and the at least one second electrode.

16. The skin treatment device of Claim 15, wherein the processor is configured to set the power of the radio frequency electromagnetic energy according to the powertemperature relationship and then to set the voltage according to the voltage-impedance relationship.

17. The skin treatment device of Claim 15 or Claim 16, wherein the voltage- impedance relationship is such that the voltage of the radio frequency electromagnetic signal applied to the skin is higher with higher measured impedance of the skin.

18. The skin treatment device according to any of the preceding claims, wherein the at least one electrode and at least one of said first and second temperature sensors are incorporated in at least one distally extending arm of the device which is configured to contact the skin of the user.

19. The skin treatment device according to claim 18, wherein the device comprises at least two distally extending arms, and wherein the first temperature sensor is incorporated on one arm and the second temperature sensor is incorporated on the other arm.

20. The skin treatment device according to claim 19, wherein the arms are movable for massaging the skin.

21. The skin treatment device according to claim 19, wherein the arms are stationary.

22. A skin treatment device, comprising:(a) at least one first electrode configured to come into electrically conductive contact with a skin of a user;(b) at least one second electrode configured to come into electrically conductive contact with a skin of a user;(c) a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the at least one first electrode and the at least one second electrode such that a radio frequency electromagnetic energy is applied to the skin; and(d) at least one processor in operable communication with the radio frequency electromagnetic signal generator, wherein the at least one processor is configured to execute program instructions, and wherein the program instructions are configured to cause the at least one processor to control the radio frequency electromagnetic signal generator to vary a voltage of the radio frequency electromagnetic signal based on an impedance of the skin according to a voltage-impedance relationship, the impedance of the skin being measured between the at least one first electrode and the at least one second electrode.

23. The skin treatment device of Claim 22, wherein the voltage-impedance relationship is such that the voltage of the radio frequency electromagnetic signal applied to the skin is higher with higher measured impedance of the skin.

24. The skin treatment device of Claim 22 or 23, wherein the voltage-impedance relationship is such that the square of the voltage of the radio frequency electromagnetic signal applied to the skin is varied proportionally with the measured impedance of the skin.

25. The skin treatment device of any one of Claims 22 to 24, further comprising at least one temperature sensor configured to measure the temperature of the skin, and wherein the radio frequency electromagnetic signal generator is configured to vary a power of the radio frequency electromagnetic energy applied to the skin according to a power-temperature relationship so as to maintain a target temperature of the skin.

26. The skin treatment device of Claim 25, wherein the radio frequency electromagnetic signal generator is configured to vary the voltage of the radio frequency electromagnetic signal based on the measured impedance of the skin according to the voltage-impedance relationship thereby varying the power of the radio frequency electromagnetic energy applied to the skin.

27. The skin treatment device of any one of Claims 22 to 26, wherein the voltageimpedance relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is below a critical low impedance.

28. The skin treatment device of any one of Claims 22 to 27, wherein the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic energy applied to the skin is started if the measured impedance increases above a starting threshold impedance.

29. The skin treatment device of any one of Claims 22 to 28, wherein the voltageimpedance relationship is such that the radio frequency electromagnetic energy applied to the skin is stopped if the measured impedance is above a critical high impedance.

30. The skin treatment device of any one of Claims 22 to 29, wherein the first and second electrodes are incorporated in at least first and second distally extending arms of the device, respectively.

31. The skin treatment device of claim 30, wherein the at least first and second arms are movable for massaging the skin.

32. The skin treatment device according to claim 30, wherein the at least first and second arms are stationary.

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