Skin treatment equipment with power regulation function

Abstract

There is provided a skin treatment device comprising: an electrode configured to make conductive contact with the skin of a user; a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the electrode such that radio frequency electromagnetic energy is applied to the skin; a first temperature sensor and a second temperature sensor both configured to measure a temperature of the skin; and a processor in operative communication with the radio frequency electromagnetic signal generator, where the processor is configured to execute program instructions, where the program instructions are configured to cause the processor to control the radio frequency electromagnetic signal generator to generate a power-to-temperature relationship based on the power-to-temperature relationship. The power of radio frequency electromagnetic energy applied to the skin is varied based on the measured skin temperature in order to maintain a target temperature of the skin.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to a skin treatment device, and more particularly to a skin treatment device that controls parameters of radio frequency electromagnetic energy applied to the skin, such as power and / or voltage. BACKGROUND

[0002] One of the goals of various cosmetic treatments is to tighten the skin, thereby imparting a smooth, wrinkle-free appearance to the skin. Over the centuries, various treatments for tightening the skin have been developed and applied.

[0003] Massaging the skin is believed to cause the skin to tighten. Proponents claim that applying massage benefits the skin by stimulating the vascular system and promoting the drainage of lymphatic fluid from the skin tissue. In addition to manual massage, various mechanical devices have been developed to massage the skin in a consistent and repeatable manner.

[0004] Other skin treatments are based on the principle of selective electrothermolysis. In selective electrothermolysis, various layers of tissue of the skin are subjected to heating. In particular, the delivery of radio frequency (RF) electromagnetic energy to various layers of tissue of the skin has been popularized as an effective method of heating the skin in a controlled manner for therapeutic purposes. The application of radio frequency energy as a skin treatment is said to increase the metabolic rate of cells, increase blood flow to the skin, cause adipocyte necrosis (adipocyte atrophy), and stimulate collagen remodeling.

[0005] Certain treatments combine massage with the simultaneous application of radio frequency (RF) electromagnetic energy to the skin.

[0006] It is an object of the present disclosure to provide a device for improved skin treatment with higher safety.

[0007] Other objects and advantages of the present disclosure will become apparent on reading the description hereinafter and on examining the drawings that accompany it. SUMMARY

[0008] In one aspect, a skin treatment device is provided. The skin treatment device includes at least one electrode configured to make conductive contact with a user's skin. The skin treatment device includes a radio frequency electromagnetic signal generator configured to supply a radio frequency electromagnetic signal to the at least one electrode such that radio frequency electromagnetic energy is applied to the skin. The skin treatment device includes a first temperature sensor configured to measure a first temperature of the skin. The skin treatment device includes 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 location spaced apart from a location at which the second temperature of the skin is measured. The skin treatment device includes 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 in order to maintain a target temperature of the skin, and wherein the power-temperature relationship is defined using one or more temperature variation metrics as inputs, the temperature variation metrics being a function of the first temperature and the second temperature.

[0009] In embodiments, the one or more temperature variation metrics include a combined measured temperature, such as an average of the first temperature and the second temperature or any other combined function thereof, and the power-temperature relationship causes the radio frequency electromagnetic signal generator to gradually decrease the power as the combined measured temperature approaches the target temperature of the skin if the combined measured temperature is below the target temperature.

[0010] In embodiments, the power-temperature relationship causes the power to vary linearly or inversely with respect to a difference between the target temperature and the combined measured temperature if the combined measured temperature is below the target temperature.

[0011] In embodiments, the power-temperature relationship causes the power to be a non-zero value when the combined measured temperature is between the target temperature of the skin and a critical high temperature of the skin.

[0012] In embodiments, the power-temperature relationship causes the power to be a non-zero value when the combined measured temperature is equal to the target temperature.

[0013] In embodiments, the power-temperature relationship causes the power to decrease inversely with respect to a difference between the target temperature and the combined measured temperature if the combined measured temperature is above the target temperature and below a critical high temperature.

[0014] In embodiments, the power-temperature relationship is such that the radiofrequency electromagnetic energy applied to the skin is stopped if the first temperature, the second temperature, their average, or another combination function exceeds a critical high temperature of the skin.

[0015] In embodiments, the power-temperature relationship is such that the power of the radiofrequency electromagnetic energy applied to the skin is the maximum set power when the combined measured temperature is below a base low temperature.

[0016] In embodiments, the skin treatment device further comprises a user interface, and wherein the user interface is configured to enable a user to set the maximum set power through the user interface.

[0017] In embodiments, the power-temperature relationship is such that: (a) the power is the maximum set power when the combined measured temperature is below a base low temperature; (b) the power varies inversely with respect to a difference between a 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.

[0018] In embodiments, the one or more temperature variation metrics comprise a temperature difference between the first temperature and the second temperature or a function thereof, and the power-temperature relationship is such that the radiofrequency electromagnetic signal generator changes the power when the temperature difference exceeds a predetermined threshold.

[0019] In embodiments, the radiofrequency electromagnetic signal generator is configured such that the radiofrequency electromagnetic signal generator stops the power when the temperature difference exceeds the predetermined temperature threshold.

[0020] In embodiments, the radiofrequency electromagnetic signal generator is configured such that the radiofrequency electromagnetic energy applied to the skin is stopped if a time during which the temperature difference between the first temperature and the second temperature exceeds a predetermined temperature difference threshold exceeds a predetermined time threshold.

[0021] In embodiments, the first temperature sensor and the second temperature sensor are independent of each other.

[0022] In embodiments, the first temperature sensor and the second temperature sensor are connected to different microcontroller unit (MCU) channels.

[0023] In embodiments, the power-temperature relationship further depends on a change over time of the temperature difference between the first temperature and the second temperature.

[0024] In some embodiments, at least one of the electrodes and at least one of the first and second temperature sensors are incorporated in at least one distal extension arm of the device, the distal extension arm being configured to contact the skin of a user.

[0025] In some embodiments, the device includes 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.

[0026] In some embodiments, the arms are movable for massaging the skin.

[0027] In some embodiments, the arms are fixed.

[0028] In some embodiments, at least one arm is movable and at least one other arm is fixed.

[0029] In embodiments, the step of varying the power of the radio frequency electromagnetic energy applied to the skin includes: (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.

[0030] In embodiments, the voltage-impedance relationship is such that the voltage of the radio frequency electromagnetic signal applied to the skin increases as the determined impedance of the skin increases.

[0031] 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.

[0032] In embodiments, the radio frequency electromagnetic signal generator is configured such that the radio frequency electromagnetic energy is started to be applied to the skin if the measured impedance increases above a start threshold impedance.

[0033] 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.

[0034] In another aspect, a skin treatment device is provided. The skin treatment device includes at least one first electrode configured to make conductive contact with a user's skin. The skin treatment device includes at least one second electrode configured to make conductive contact with the user's skin. The skin treatment device includes 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 radio frequency electromagnetic energy is applied to the skin. The skin treatment device includes 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, where the impedance of the skin is measured between the at least one first electrode and the at least one second electrode.

[0035] In embodiments, the voltage-impedance relationship is such that the voltage of the radio frequency electromagnetic signal applied to the skin increases as the measured impedance of the skin increases.

[0036] In embodiments, the voltage-impedance relationship is such that the square of the voltage of the radio frequency electromagnetic signal applied to the skin varies in proportion to the measured impedance of the skin.

[0037] In embodiments, the skin treatment device includes at least one temperature sensor configured to measure a 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 in order to maintain a target temperature of the skin.

[0038] In embodiments, where 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 a voltage-impedance relationship, the power of the radio frequency electromagnetic energy applied to the skin is varied.

[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 is started to be applied to the skin if the measured impedance increases above a start 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 further depends on a change in the measured impedance over time. In embodiments, the voltage-impedance relationship further depends on a change in the measured impedance over time, including a change in impedance between two separate treatments.

[0043] In another aspect, a skin treatment device is provided. The skin treatment device includes at least one electrode configured to make conductive contact with a user's skin. The skin treatment device includes a radiofrequency electromagnetic signal generator configured to supply a radiofrequency electromagnetic signal to the at least one electrode such that radiofrequency electromagnetic energy is applied to the skin. The skin treatment device includes a first temperature sensor configured to measure a first temperature of the skin. The skin treatment device includes 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 location spaced apart from a location at which the second temperature of the skin is measured. The skin treatment device includes at least one processor in operable communication with the radiofrequency 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 radiofrequency electromagnetic signal generator such that radiofrequency 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 radiofrequency electromagnetic signal generator such that radiofrequency electromagnetic energy applied to the skin is stopped if both of the following two conditions are met: i) the temperature difference between the first temperature and the second temperature exceeds the predetermined temperature difference threshold; and ii) a time over which the temperature difference exceeds the predetermined temperature difference threshold exceeds a predetermined time threshold.

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

[0046] In embodiments, the first temperature sensor and the second temperature sensor are independent of 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, a method of controlling a skin treatment device is provided. The method includes supplying a radiofrequency electromagnetic signal to at least one electrode of the skin treatment device. The method includes receiving a temperature measurement. The method includes varying the power of the radiofrequency electromagnetic energy based on the measured temperature according to a power-temperature relationship.

[0049] In an embodiment, the method includes receiving an impedance measurement. The method includes varying the 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to better understand the subject matter disclosed herein and to illustrate how it may be implemented in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0051] Figure 1A A skin treatment device according to one embodiment of the present disclosure is shown;

[0052] Figure 1B yes Figure 1A A zoomed-in view of the device's massage arm, showing the temperature sensor;

[0053] Figure 2 yes Figure 1A A block diagram of the electrical system of the skin treatment device 10;

[0054] Figure 3 According to one embodiment of the present disclosure Figure 1A Operational flow chart of skin treatment equipment;

[0055] Figure 4 Shown in Figure 1A Exemplary power-temperature relationships used in the operation of skin treatment devices;

[0056] Figure 5 shows an exemplary voltage-impedance relationship used in the operation of the skin treatment device of FIG. 1 ; and

[0057] Figure 6 A skin treatment device having a fixed arm according to another embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0058] In the following detailed description, numerous specific details are set forth in order to provide a comprehensive understanding of the embodiments of the present disclosure. However, it will be understood by those skilled in the art that the present disclosure can be practiced without these specific details. In other cases, well-known methods, procedures, components, modules, units, and / or circuits have not been described in detail in order to avoid obscuring the present disclosure.

[0059] According to embodiments of the present disclosure, a skin treatment device includes two or more radio frequency (RF) electrodes. Each radio frequency electrode is incorporated in one massage arm. One or more of these massage arms are movable, e.g., to perform a reciprocating motion, a lateral motion, a circular motion, and / or a vibrating motion. Alternatively, in some embodiments, one or more arms of the device are stationary.

[0060] Although the drawings refer to a skin treatment device having one or more massage arms, any reference herein to a massage arm is purely optional. In other words, a skin treatment device can not include any massage functionality / massage arms.

[0061] The skin treatment device can include a mechanism for coordinating movement of two or more massage arms. For example, the coordinated movement can cause the distal ends of the two massage arms to alternately move closer to and further away from each other. The motion can be repetitive or periodic.

[0062] The frequency or speed of the massage arm motion can be adjustable. Similarly, the distance that the massage arms move during the motion (e.g., the amplitude of the motion) can be adjustable.

[0063] As an alternative to coordinated motion of two or more massage arms, one massage arm can move relative to one or more stationary adjacent massage arms. References herein to motion of a massage arm should be understood to refer to motion of the massage arm relative to the other massage arms, regardless of how many massage arms move relative to the rest of the skin treatment device.

[0064] The skin treatment device includes an electronic circuit for applying radio frequency electromagnetic signals to the radio frequency electrodes incorporated in each massage arm. For example, radio frequency electromagnetic signals of opposite polarity can be simultaneously applied to two (or more) massage arms. As described below, the frequency or amplitude (and thus power) of the radio frequency signals can be adjustable. Optionally, the frequency, amplitude, or other characteristic of the radio frequency signals can be generated so that they vary in a periodic manner. For example, the variation in the radio frequency signal characteristics applied to the massage arms can be coordinated with the motion of the massage arms.

[0065] In some embodiments, the user selects (such as via a device user interface) one or both of: the level of energy to be applied, the extent and / or speed of the massage arm movement.

[0066] A skin treatment device according to embodiments of the present disclosure can be portable. For example, the components of the skin treatment device can be housed within a single housing. The size of the housing can be designed to allow the skin treatment device to be held in a single hand. The shape of the skin treatment device can be designed to be safely and comfortably held in the hand. Optionally, the skin treatment device can be powered by a battery. Optionally, the skin treatment device is rechargeable.

[0067] A skin treatment device according to embodiments of the present disclosure can be operated while in contact with skin. For example, a user of the device can hold the skin treatment device so that the massage arms are in contact with the user's own skin, or with the skin of another person for whom the user is performing skin treatment. Operation of the skin treatment device can include moving the massage arms while applying a radio frequency electromagnetic signal to the massage arms.

[0068] Mechanical movement of the massage arms can massage the skin to which the skin treatment device is applied. For example, the massage arms can be moved in a periodic, reciprocating motion, moving closer together and further apart from each other. This periodic, reciprocating motion can in turn alternately compress (pinch) and stretch the skin located between the massage arms. The movement of the massage arms can be configured to ensure that the resulting massage is comfortable or tolerable, and does not cause any pain or discomfort (e.g., due to excessive force being applied to the skin). The user can manually adjust the force with which the skin treatment device presses against the treated skin.

[0069] Simultaneous application of the radio frequency electromagnetic signal to the skin can cause a radio frequency current to flow through the skin. The radio frequency current flowing through the skin can in turn heat the skin (electrothermal decomposition of the skin).

[0070] The depth at which the radio frequency current flows beneath the surface of the skin can be determined by one or more factors. These factors can include, for example, the frequency of the applied radio frequency electromagnetic signal, the temperature of the skin, the electrical conductivity of the skin, and the spacing between the electrodes (one at the distal end of each massage arm, or equivalently, the outer surface of the massage arms) through which the radio frequency electromagnetic signal is applied to the skin. Movement of the distal ends of the two massage arms alternately closer together and further apart from each other causes the spacing between the electrodes to increase and decrease during the movement. Thus, the increase and decrease in spacing can change the depth of the radio frequency current within the skin, and thus the depth of the heating (electrothermal decomposition). Thus, simultaneous application of the radio frequency electromagnetic signal to the skin while the electrodes are reciprocally moved, can enable repeated heating of various layers within the skin over a range of depths.

[0071] One or more of the massage arms can be provided with a temperature sensor. The temperature sensor can be in thermal contact with the skin when the skin treatment device or the massage arms of the skin treatment device are placed in contact with the skin. The temperature sensor can generate a voltage or other electrical signal indicative of the measured temperature of the skin. In some embodiments, a temperature sensor can be provided on each massage arm. Each temperature sensor can sense the temperature of the skin at the respective point of contact between the massage arm and the skin while the massage arm conducts the radio frequency electromagnetic signal to the point of contact.

[0072] Circuitry for controlling the generation of the radio frequency electromagnetic signal, or a controller, can be coupled with the temperature sensor. The circuitry can be configured to control the radio frequency electromagnetic signal based on the temperature measured by the temperature sensor.

[0073] A skin treatment device according to embodiments of the present disclosure can be configured for home use or for use by a non-professional user. In certain embodiments, a skin treatment device according to embodiments of the present disclosure can be configured for professional use by a professional user. For example, the skin treatment device can be small enough to be stored like other home-use cosmetic or skin care products and devices. In addition, the small size and ergonomic shape of the skin treatment device can enable it to be held and operated without the aid of any clamps or other support structures. The skin treatment device can include built-in safety features to enable safe operation by a non-professional user. According to some embodiments, the device includes a flexible boot to prevent skin exposure to the device's electrical circuitry. The flexible boot seals the space between the arms and the housing and accommodates pinched skin within its recesses to avoid contact of pinched skin with any internal components of the device while not interfering with the movement of the massage arms. Thus, the device is adapted for safe and reliable use by a non-professional user.

[0074] Skin treatment using a skin treatment device according to embodiments of the present disclosure can be beneficial. A skin treatment device as described herein can provide safe and effective skin heating.

[0075] Figure 1A A skin treatment device 10 according to one embodiment of the present disclosure is shown.

[0076] The skin treatment device 10 includes a housing 11. The housing 11 can be configured in an ergonomic shape to enable a user to hold the skin treatment device 10 in one hand. The shape of the housing 11 can be configured to enable the massage arms 12 to be held or pressed against the skin to be treated. The shape of the housing 11 can also enable convenient and effective operation of the skin treatment device 10. The housing 11 can be comprised of a rigid, electrically insulating material (e.g., plastic) to electrically and mechanically isolate a user of the skin treatment device 10 from any internal electrical or mechanical components of the skin treatment device 10. The housing 11 can be designed to isolate the internal components of the skin treatment device 10 from environmental factors (e.g., moisture or corrosive materials) that can adversely affect the operation of the internal components.

[0077] The massage arms 12 extend from the end of the skin treatment device 10 that is configured to be placed against the skin to be treated. The massage arms 12 are configured to move in a coordinated manner, alternating between being close to and far from each other. Thus, when placed against the skin, the coordinated movement of the massage arms 12 can cause the area of skin between the massage arms 12 to be gently pinched and released. Thus, the skin can be massaged by the movement of the massage arms 12. It is contemplated that any other movement of the massage arms 12 (e.g., random relative movement) can be used by the present disclosure, as understood by one skilled in the art.

[0078] Each massage arm 12 can have a rounded profile (e.g., no sharp edges or corners) to prevent scratching or gliding smoothly over the skin. The surface of the massage arm 12 can be ribbed, embossed, dimpled, or otherwise patterned to facilitate grasping or gripping the skin.

[0079] A material can be selected for the outer surface of each massage arm 12 to avoid irritating or abrading the skin. A lubricating liquid, gel, or cream can be applied to each massage arm 12 and / or the user's skin before or during use. The lubricating liquid, gel, or cream can be electrically conductive.

[0080] The flexible sheath 13 of the device 10 can be made of a flexible material, such as a flexible plastic or rubber. The flexibility of the flexible sheath 13 can enable the housing 11 to remain sealed while still allowing the massage arms 12 to move.

[0081] In the illustrated embodiment, the skin treatment device 10 includes two massage arms 12. In other embodiments, more than two massage arms can be included. For example, multiple massage arms can be arranged in cooperating pairs. The massage arms of each cooperating pair can be movable in a coordinated manner. In other embodiments, three or more massage arms can be placed in a row and driven to move in a coordinated manner. For example, a massage arm positioned between two adjacent massage arms can move alternately toward one of the adjacent massage arms and then the other. The adjacent massage arms can be fixed or movable. In other embodiments, a single massage arm can be used, for example, having a rotational motion, a vibrational motion, or other suitable motion for massaging tissue.

[0082] A portion or all of the outer surface of each massage arm 12 can include or be made of an electrically conductive material. For example, the electrically conductive material can include a metal, an electrically conductive plastic, or another electrically conductive material suitable for inclusion in the outer surface of the massage arm 12. The electrically conductive material, acting as an electrode, can facilitate electrical coupling of the massage arm 12 to the skin to be treated.

[0083] The skin treatment device 10 can include a user interface 14. The user interface can include one or more controls. For example, the controls can include one or more buttons (as shown), switches, joysticks, dials, or knobs. The user can operate the controls in order to control the operation of the skin treatment device 10. For example, operating the controls can power the skin treatment device 10 on or off, set a treatment power, or enter a standby state. Operating the user interface 14 can indicate that a mode of operation of the skin treatment device 10 has been selected.

[0084] The operational user interface 14 can start or stop movement of the massage arm 12. The operational user interface 14 can change or select a speed, distance (e.g., amplitude), or other characteristic of the movement. For example, the operational user interface 14, in the form of a button, can change a state of movement of the massage arm 12 from one state to the next in accordance with a predetermined sequence of states. As another example, the operational user interface 14 can select a characteristic of the movement from a set of predetermined characteristics.

[0085] The operational user interface 14 can start or stop generation of the radio frequency electromagnetic signal conducted into the skin by the massage arm 12. The operational user interface 14 can resume generation of the radio frequency electromagnetic signal after an interruption (e.g., caused in response to detection of a high skin temperature, as described below). The operational user interface 14 can change a frequency, amplitude, or other characteristic of the radio frequency electromagnetic signal applied by the massage arm 12. For example, continuous operation of a control of the operational user interface 14 can cause a set power of the radio frequency electromagnetic signal to change in accordance with a predetermined sequence of signal characteristics.

[0086] The user interface 14 can include one or more indicators 16. For example, the indicators 16 can include lighted or other visible indications of a state of the skin treatment device 10. The indicators 16 can include light emitting diodes (LEDs), light bulbs, or other light emitting devices placed on or near a surface of the skin treatment device 10 or housing 11 (e.g., protected or encapsulated by a transparent or translucent window, dome, or enclosure). The indicators 16 can include light emitting devices (e.g., light bulbs or LEDs) located inside the skin treatment device 10 whose light is directed to an outer surface of the skin treatment device 10 or housing 11 (e.g., by a fiber optic or other light guiding device). For example, one or more of the indicators 16 can indicate a power state of the skin treatment device 10 (e.g., powered on, powered off, on standby).

[0087] One or more of the indicators 16 can indicate a current state of movement of the massage arm 12. The state of movement can include, for example, movement on or off, a speed, an amplitude, or other movement characteristic, or a current state of movement selected from a limited set of predetermined movement states.

[0088] One or more of the indicators 16 can indicate a current state of radio frequency electromagnetic signal movement currently applied by the massage arm 12. The state of the applied radio frequency electromagnetic signal can include, for example, whether signal generation is currently on or off, a frequency, amplitude, or other characteristic of the signal, or whether current generation has been interrupted (e.g., due to detection of a high skin temperature).

[0089] In addition to or instead of visible indications, the skin treatment device 10 can be configured to generate audible signals to indicate a current state of the skin treatment device 10 or a change in a current state.

[0090] The skin treatment device 10 can include one or more connectors 18. The connectors 18 can be configured to connect to connectors of respective appropriate cables.

[0091] For example, the connectors 18 can be configured to allow the skin treatment device 10 to be connected to an external power source (e.g., mains or grid electricity, or a power adapter, converter, or transformer) through appropriate power cables. According to some embodiments of the skin treatment device 10, the skin treatment device 10 can incorporate an internal power source. For example, the internal power source can include a replaceable or rechargeable battery or cell. The rechargeable battery can be charged by connecting an appropriate connector 18 to an external power source. In other embodiments, the power to operate the skin treatment device 10 is provided solely by an external power source connected to the connectors 18.

[0092] The connectors 18 can be configured to connect the built-in processor of the skin treatment device 10 to a data port of an external computer, controller, or other device. For example, such a data connection can enable configuration of the skin treatment device 10. In this case, the operating parameters of the skin treatment device 10 can be set or modified by a user or external device. In this way, the skin treatment device 10 can be configured according to, for example, the user's preferences, or according to the manufacturer's changing recommendations (e.g., a particular motion scheme for the motion of the massage arms 12, or a scheme for generating a particular radio frequency electromagnetic signal). Such a data connection can also facilitate diagnosis of operational problems with the skin treatment device 10.

[0093] Figure 1B is Figure 1A A close-up view of a device massage arm, with a temperature sensor visible. As shown, a temperature sensor 30 can be mounted on each massage arm 12 for sensing the temperature of the skin contacted by that arm. Some embodiments can include more than one sensor on each arm.

[0094] In some embodiments, during a massage motion, the arm moves over a relatively small surface area of the skin, in which case it is assumed that the skin is uniformly heated by the radio frequency energy. In addition, the measurement can take into account the thermal capacity of the arm itself, which can for example cause a certain time lag between the actual skin temperature and the measured skin temperature.

[0095] Figure 2 is a block diagram of an electrical system 20 for operating a skin treatment device 10 according to embodiments of the present disclosure.

[0096] The electrical system 20 may include a controller 40 for controlling the operation of the skin treatment device 10. The controller 40 may represent a single unit or multiple units in communication with each other that are configured to coordinate the various components of the electrical system 20. The controller 40 may include or be composed of one or more processors that are configured to operate according to programmed instructions. In another example, the controller 40 may include circuitry (e.g., in the form of an integrated control circuit) that is configured to operate the components of the skin treatment device 10.

[0097] Controller 40 can communicate with data storage unit 42. Data storage unit 42 can include one or more volatile or non-volatile data storage devices, or can represent data storage functionality of the device. For example, data storage unit 42 can include a non-volatile data storage device for storing programming instructions or data for operating skin treatment device 10 according to some embodiments of the present disclosure. Data storage unit 42 can be used to store data generated by controller 40, which is in the form of a processor, during operation of skin treatment device 10.

[0098] The controller 40 may be configured to detect operation of the user interface 14. The controller 40 may operate based on the detected user operation of one or more controls of the user interface 14.

[0099] The controller 40 may be configured to operate one or more indicators 16. For example, the indicator 16 may be operated to indicate the current state or operating status of the controller 40 or a component of the electrical system 20.

[0100] The controller 40 can communicate with components and circuitry for generating radio frequency electromagnetic signals. Specifically, the controller 40 can control a radio frequency electromagnetic signal generator 44. The radio frequency electromagnetic signal generator 44 is configured to supply radio frequency electromagnetic signals to the electrodes 45, thereby applying radio frequency electromagnetic energy to the skin. The radio frequency electromagnetic signal generator 44 can represent one or more components or modules of the controller 40, can include components independent of the controller 40, or can be a combination of both. The radio frequency electromagnetic signals generated by the radio frequency electromagnetic signal generator 44 can be transmitted to one or more massage arms 12, and ultimately to the electrodes 45 on each massage arm 12, thereby inducing radio frequency currents in the skin contacting the electrodes 45.

[0101] The controller 40 and / or the RF electromagnetic signal generator 44 can be configured to measure the impedance between the electrodes 45, as will be understood by those skilled in the art. Thus, during operation, the electrodes 45 can be used to measure the impedance of the skin between the electrodes 45. The impedance measurement can be used to control the RF electromagnetic signal generator 44 in real time to select a particular RF electromagnetic signal (e.g., by varying the voltage of the signal).

[0102] In summary, the controller 40 can control the radio frequency electromagnetic signal generator 44 to select a radio frequency electromagnetic signal based on user operations of the user interface 14, measurements from the temperature sensor 30, measurements of the impedance between the electrodes 45, program instructions stored on the data storage 42, and any other measurements performed by the skin treatment device 10.

[0103] The controller 40 can be in communication with components and circuitry for controlling the movement of a moving component, such as the massage arm 12. The movement controller 48 can be configured to operate the motor 22. For example, the movement controller 48 can be configured to adjust the current supplied to the drive motor 22 to cause the drive motor 22 to operate at a particular speed. Operation of the drive motor 22 can cause the massage arm 12 to move in a predetermined manner.

[0104] The movement controller 48 can be configured to monitor the current supplied to the drive motor 22. For example, monitoring the current supplied to the drive motor 22 can allow detection of a condition in which the movement of the massage arm 12 is obstructed or impeded.

[0105] The electrical system 20 can include a power source 50. The power source 50 can provide power for the operation of the controller 40 or the operation of another component of the electrical system 20. The power source 50 can include a replaceable or rechargeable power source, such as a replaceable or rechargeable battery or cell. The power source 50 can be connected to an external power source, such as a power grid, a generator, or a power source device, through the connector 18. The power source 50 can include appropriate converters or transformers for converting input current from the connector 18 to current that can be used to operate one or more components of the skin treatment device.

[0106] The electrical system 20 can be connected to or in communication with one or more temperature sensors 30. The temperature sensors 30 can be mounted on the massage arms 12. The temperature sensors 30 can be embedded within the massage arms 12 or can be in thermal contact therewith. In some embodiments, one temperature sensor 30 can be provided in each massage arm 12. Optionally, the temperature sensor is at least partially embedded in the radio frequency electrode.

[0107] Each temperature sensor 30 can sense the temperature of the skin at a respective contact point of the corresponding massage arm 12 in contact with the skin. Thus, the temperature sensor 30 is configured to sense the temperature of the skin at the contact point at which the electromagnetic radio frequency signal is provided to the skin, thereby ensuring a higher accuracy in sensing the temperature of the skin at the contact point receiving the electromagnetic radio frequency signal and making the operation of the device more efficient and effective.

[0108] Figure 3 An operational flowchart 100 of the skin treatment device 10 according to one embodiment of the present disclosure is shown.

[0109] At step 110, the user turns on the skin treatment device 10. At this step, the user can use the user interface 14 to set various user settings for the skin treatment device 10, as described above.

[0110] Once the skin treatment device 10 is in operation, a measurement of the impedance between the electrodes 45 is performed. For example, the skin impedance between the electrodes is measured when the electrodes 45 are in contact with the skin. This step is optional, and in alternative embodiments the method moves to step 130 without performing an impedance measurement.

[0111] At step 130, the skin treatment device 10 measures the skin temperature using the temperature sensor 30. For example, the skin treatment device can use at least two spaced apart temperature sensors such that a first temperature is measured at one location of the skin and a second temperature of the skin is measured at a location spaced apart therefrom. In examples where each massage arm includes one temperature sensor, the spacing between the temperature sensors corresponds to the spacing between the massage arms. In some examples, such spacing can be in the range of 14 mm to 22 mm, 5 mm to 15 mm, 10 mm to 30 mm, or intermediate, greater or smaller spacings.

[0112] At step 140, the controller 40 controls the radio frequency electromagnetic signal generator 44 to vary the power of the radio frequency electromagnetic energy applied to the skin based on the measured skin temperature according to a power-temperature relationship in order 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” can refer to the (desired) power (e.g., in the form of heat energy) received / absorbed by the skin. The power intended to be absorbed by the skin can be varied by varying 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 can be varied, thereby varying the power of the radio frequency electromagnetic energy applied to the skin. As described in more detail below, in certain embodiments, the voltage of the radio frequency electromagnetic signal is varied according to the measured skin impedance, thereby varying the power of the radio frequency electromagnetic energy applied to the skin. In such embodiments, the desired power level can be more accurately applied regardless of the composition of the skin.

[0113] At optional step 150, the user settings are again checked to see if the user has selected any new settings using the user interface 14. If the user settings indicate that the treatment should continue, the method moves to step 160, which is a pause. The pause can be any duration, for example 0.1 seconds to 1 second. Thereafter, the method loops back to step 120. The pause 160 is optional, and the method can also loop back to step 120 immediately.

[0114] If at step 150 the user sets the treatment to end, the method moves 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 to step 180 in which the particular treatment is completed. From this state, the user can select another treatment using the user interface 14, or turn off the power to the device entirely (e.g., by disconnecting the mains power).

[0115] Further details of step 140 will now be 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 skin temperature according to a power-temperature relationship, so as to maintain a target temperature of the skin. This enables precise heating of the skin within a strict limit, thereby improving the safety and effectiveness of the treatment.

[0116] The power-temperature relationship can be predefined and stored on the data storage 42 for access by the controller 40. The power-temperature relationship can take as input the measured temperature from the temperature sensor 30 and provide as output the power. The power-temperature relationship can additionally or alternatively take as input one or more temperature variation metrics and provide as output the power. The one or more variation metrics can include a combined measured temperature, which can be defined as an average of the first temperature and the second temperature and / or a difference between the first temperature and the second temperature. The power provided by the power-temperature relationship can be the power that should be applied to the skin by the radio frequency electromagnetic energy. The power-temperature relationship can be defined in a variety of different forms, such as a mathematical equation (or equations) and / or a table containing a plurality of associated powers and temperatures.

[0117] In conjunction with Figure 4 An exemplary power-temperature relationship is explained. The measured temperature T is set as the independent variable of the graph, while the power P is set as the dependent variable. The power-temperature relationship is defined so as to maintain a target temperature T T .

[0118] As can be seen from Figure 4 , if the measured temperature T is less than or equal to a base low temperature T L , the power P is set to a maximum set power P M . The maximum set power P M may be set directly by the user using the user interface 14, or can be predetermined and fixed. In this way, the skin treatment device 10 can quickly heat the skin to a temperature at which the treatment becomes effective. This can improve the efficiency of the treatment.

[0119] The maximum set power P MIt may be between about 2W and about 8W, optionally between about 3W and about 7W, and further optionally between about 4W and about 6W.

[0120] If the measured temperature T is greater than the basic low temperature T L and lower than the target temperature T T , then the power P is relative to the target temperature T T The difference between the measured temperature T and the measured temperature T changes linearly. In other words, if the measured temperature T is greater than the basic low temperature T L and lower than the target temperature T T , then power P = -kT + c (where k and c are positive constants). This can provide greater control over skin temperature and reduce skin temperature beyond the target temperature T T When the measured temperature T is T L and T T By gradually reducing the power, the target temperature T can be reached more accurately. T This type of control can be implemented when the target temperature is first reached, or any time the temperature drops from the target temperature, even if the drop is small.

[0121] If the measured temperature T is equal to the target temperature T T , then the power is set to maintain power P H Maintaining power P H Can be non-zero value. Maintain power P H May be sufficient to maintain a stable skin temperature T T In some embodiments, the maintenance power P H It may be between about 250 mW and about 350 mW, optionally between about 275 mW and about 325 mW, and further optionally about 300 mW.

[0122] If the measured temperature T is greater than the target temperature T T , then the power P decreases. Figure 4 As shown, the power P is relative to the target temperature T T Changes inversely proportional to the difference between the measured temperatures T.

[0123] If the measured temperature T is greater than or equal to the critical high temperature T C , then the power P is zero (ie, the radio frequency electromagnetic energy applied to the skin is stopped).

[0124] In certain embodiments, if the measured temperature T is greater than the target temperature T T But below the critical high temperature T C , then the power P is non-zero. This prevents the skin from reaching the target temperature T T Then it becomes too cold.

[0125] Figure 4 Various modifications can be made in nature that is exemplary. For example, in alternative embodiments, if the measured temperature T is greater than the base low temperature T L and less than the target temperature T T , the power P varies inversely with respect to the difference between the target temperature T T and the measured temperature T.

[0126] In some embodiments, the power-temperature relationship can include a first varying portion and a second varying portion: in the first varying portion, the measured temperature (or an indicative function thereof, such as an average of the measured temperature) is between the base low temperature and the target temperature, in the second varying portion, the measured temperature (or an indicative function thereof, such as an average of the measured temperature) is between the target temperature and the critical high temperature, wherein in the first and second varying portions, the power varies with respect to the measured temperature (or an indicative function thereof) according to different power-temperature relationships. In the first portion, the variation of the power with respect to the measured temperature (or an indicative function thereof) can be directly proportional (or inversely proportional in other embodiments) to the difference between the measured temperature (or a function thereof) and the base low temperature. In the second portion, the variation of the power with respect to the measured temperature (or an indicative function thereof) can be inversely proportional (or inversely proportional in other embodiments) to the difference between the measured temperature (or an indicative function thereof) and the target temperature.

[0127] In step 140, once the desired power is determined according to the output of the power-temperature relationship, the controller 40 sets the voltage (i.e. amplitude) of the radio frequency electromagnetic signal applied by the radio frequency electromagnetic signal generator 44 in order to achieve the desired power level.

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

[0129]

[0130] where V rms is the root mean square voltage, I is the impedance, and P is the desired power. By using the measured value of the skin impedance, the correct power can be applied to the skin regardless of the skin composition, thereby improving the safety and effectiveness of the treatment.

[0131] An exemplary voltage-impedance relationship is explained in connection with Figure 5 The measured impedance I is set as the independent variable of the graph, while V rms 2The dependent variable that is charted. The voltage-impedance relationship is defined in order to maintain the desired RF electromagnetic energy power applied to the skin (determined by the power-temperature relationship described above) regardless of the skin composition / type.

[0132] As can be seen from Figure 5 during operation of the skin treatment device 100, if the measured impedance is below the critical low impedance I L or above the critical high impedance I H , the RF electromagnetic energy applied to the skin is stopped. This is used as a safety feature to avoid applying RF electromagnetic energy when not in contact with the skin.

[0133] In certain embodiments, the critical low impedance I L is between about 100 ohm and 150 ohm, optionally between about 110 ohm and 140 ohm, and further optionally between about 120 ohm and 130 ohm.

[0134] In certain embodiments, the critical high impedance I H is between about 250 ohm and 300 ohm, optionally between about 260 ohm and 290 ohm, and further optionally between about 270 ohm and 280 ohm.

[0135] In certain embodiments, the skin treatment device 10 can be configured to automatically start applying RF electromagnetic energy upon detection of the skin (e.g., when the measured impedance is between the critical low impedance I L and the critical high impedance I H .

[0136] In some embodiments, the skin impedance is continuously measured and the voltage is iteratively adjusted in response to the sensed impedance in order to reach the desired power level.

[0137] In certain implementations, two or more temperature sensors 30 can be used. For example, one temperature sensor can be provided on each massage arm 12. In certain embodiments, the two or more temperature sensors are spaced apart such that their respective temperature measurements are taken at spaced apart locations on the skin. Using two spaced apart temperature sensors ensures that the skin temperature is monitored at different locations, which means that any hot spots can be detected.

[0138] In such implementations, the method 100 can optionally be modified to include an override routine such that if the temperature difference between two or more temperature sensors exceeds a predetermined temperature difference threshold, the application of radio frequency electromagnetic energy to the skin is stopped. The temperature difference exceeding the temperature difference threshold can imply that the skin is being unevenly heated (which can be a safety concern) and / or that the skin treatment device 10 is malfunctioning. The predetermined temperature difference threshold can be from about 1 degree to about 5 degrees, optionally from about 2 degrees to about 4 degrees, and further optionally about 3 degrees.

[0139] In certain embodiments, the application of radio frequency electromagnetic energy 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 from about 3 seconds to about 7 seconds, optionally from about 4 seconds to about 6 seconds, and further optionally about 5 seconds.

[0140] The use of a minimum time threshold before stopping the radio frequency electromagnetic energy can mean that temporary fluctuations in the skin temperature are tolerated up to a certain predetermined limit.

[0141] In certain embodiments, the application of radio frequency electromagnetic energy to the skin is stopped immediately if any of the two or more temperature sensors 30 measures a temperature that exceeds the critical high temperature Tc. This provides a safety mechanism for the skin treatment device 10.

[0142] Throughout this disclosure, if the skin treatment device 10 includes two or more temperature sensors 30, the term "measured temperature" as referred to herein can be an average of the temperatures measured by each of the two or more sensors, or any other combination function thereof (e.g., a weighted average of the temperatures measured by each of the two or more sensors). In some embodiments, the temperature of a single sensor used to calculate the multiple sensor average (or other combination function) is the temperature measured at a selected (e.g., predetermined) point in time. Alternatively, the sensor temperature used for the calculation includes an average (or any other suitable function) of the temperatures measured over time by that particular single sensor.

[0143] While the exemplary embodiments present a structure with massage arms, the massage arms are optional and can be removed. In other words, the skin treatment device can not include a massage function / massage arms. In such cases, one or more electrodes can be provided on the device body so as to come into contact with the skin of the user. Figure 6An example of a device with fixed arms, specially designed and configured for contact with the skin, is shown. Device 60 is a hand-held device in some embodiments, having an elongated body 62 and a head 64 at the distal end of the body. A plurality of fixed arms 66 (e.g., 4 arms as shown; other embodiments can include a different number of arms) extend distally from the head for contact with the user's skin. A radio frequency electrode can be incorporated in each arm. One or more temperature sensors can be incorporated in the arms, e.g., one temperature sensor per arm. In the example shown, the temperature sensors are not visible because they are embedded inside the arm body, and the outer surface of the arms is thin enough (at least at the location of the temperature sensors) to enable the sensors to detect the temperature of the skin or at least a temperature indicative of the temperature of the skin. Additionally, in some embodiments, the arms can be constructed of a thermally conductive material (e.g., metal) that essentially acts as the surface of the temperature sensor (embedded within the arm). In other examples, e.g., as shown by the device of Figure 1A

[0144] In use, the user holds the device with the distal ends of the arms in contact with the skin, and can move the device over the skin to treat additional sites. Thus, although the arms themselves are stationary, movement of the device as a whole causes the arms to move over the surface of the skin.

[0145] Figure 6 The circuitry, operation, and control of the device can be as described above, e.g., so aspects related to arm movement are not applicable to Figure 6 .

[0146] While two example embodiments have been presented in the foregoing detailed description, it should be understood that there are numerous variations.

[0147] For example, in alternative embodiments, a single (e.g., rotating) massage arm can be used. In such embodiments, a second electrode can be placed at a fixed location on the user's skin (e.g., using an adhesive conductive pad).

[0148] It should also be understood that one or more example embodiments are merely 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 one or more example 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

1. A skin treatment device comprising: (a) at least one electrode configured to make conductive contact with the 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 so that 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 location spaced apart from a location at which the second temperature of the skin is measured; as well as (e) at least one processor in operable communication with the RF 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 RF electromagnetic signal generator to vary the power of the RF 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 using one or more temperature change metrics as input, the temperature change metrics comprising a combined measured temperature that is a function of the first temperature and the second temperature; and wherein if the combined measured temperature is above a basal low temperature and below the target temperature, the power-temperature relationship causes the RF electromagnetic signal generator to gradually decrease the power as the combined measured temperature approaches the target temperature of the skin. 2 . The skin treatment device according to claim 1 , wherein the combined measured temperature is an average of the first temperature and the second temperature.

3. The skin treatment device according to claim 1 or claim 2, wherein: If the combined measured temperature is lower than the target temperature, the power-temperature relationship is such that the power varies linearly or inversely with respect to the difference between the target temperature and the combined measured temperature.

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

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

6. A skin treatment device according to any one of the preceding claims, wherein If the combined measured temperature is higher than the target temperature and lower than a critical high temperature, the power-temperature relationship is such that the power is reduced in inverse proportion to the difference between the target temperature and the combined measured temperature.

7. A skin treatment device according to any of the preceding claims, wherein the power-temperature relationship is such that the radiofrequency electromagnetic energy applied to the skin is stopped if the first temperature, the second temperature, their average, or some other combined function exceeds a critical high temperature of the skin.

8. The skin treatment device of any one of the preceding claims, wherein the power-temperature relationship is such that when the combined measured temperature is below the fundamental low temperature, the power of the radiofrequency electromagnetic energy applied to the skin is at a maximum set power.

9. The skin treatment device according to claim 8, further comprising a user interface, and wherein the user interface is configured to enable the user to set the maximum setting power through the user interface.

10. A skin treatment device according to any one of the preceding claims, wherein the power-temperature relationship is such that: (a) when the combined measured temperature is lower than the basic low temperature, the power is the maximum set power; (b) when the combined measured temperature is greater than the basic low temperature and lower than the target temperature, the power varies in inverse proportion to the difference between the target temperature and the combined measured temperature; and (c) if the combined measured temperature exceeds a critical high temperature, stopping the power.

11. A skin treatment device according to any of the preceding claims, wherein the one or more temperature change metrics include 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 changes the power when the 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 the temperature difference exceeds the predetermined temperature threshold.

13. The skin treatment device according to claim 11, wherein the radiofrequency electromagnetic signal generator is configured to stop applying the radiofrequency electromagnetic energy to the skin if the temperature difference between the first temperature and the second temperature exceeds a predetermined temperature difference threshold for a time period exceeding a predetermined time threshold.

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

15. A skin treatment device according to 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 the voltage of the radio frequency electromagnetic signal based on the impedance of the skin according to a voltage-impedance relationship, wherein the impedance of the skin is 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 radiofrequency electromagnetic energy according to the power-temperature relationship and then set the voltage according to the voltage-impedance relationship.

17. A skin treatment device according to claim 15 or claim 16, wherein the voltage-impedance relationship is such that the voltage of the radiofrequency electromagnetic signal applied to the skin increases as the measured impedance of the skin increases.

18. A skin treatment device according to any of the preceding claims, wherein the at least one electrode and at least one of the first temperature sensor and the second temperature sensor are incorporated into at least one distal extension arm of the device, the distal extension arm being configured to contact the skin of the user.

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

20. The skin treatment device of claim 19, wherein the arm is movable for massaging the skin.

21. The skin treatment device of claim 19, wherein the arm is fixed.

22. A skin treatment device comprising: (a) at least one first electrode configured to make conductive contact with the skin of a user; (b) at least one second electrode configured to make conductive contact with the user's skin; (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, causing radiofrequency electromagnetic energy to be applied to the skin; as well as (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, wherein the impedance of the skin is 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 increases as the measured impedance of the skin increases.

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 radiofrequency electromagnetic signal applied to the skin varies proportionally to the measured impedance of the skin.

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

27. A skin treatment device according to any one of claims 22 to 26, wherein the voltage-impedance relationship is such that if the measured impedance is below a critical low impedance, application of the radiofrequency electromagnetic energy to the skin is stopped.

28. A skin treatment device according to any one of claims 22 to 27, wherein the radiofrequency electromagnetic signal generator is configured such that application of the radiofrequency electromagnetic energy to the skin is initiated if the measured impedance increases above a start threshold impedance.

29. A skin treatment device according to any one of claims 22 to 28, wherein the voltage-impedance relationship is such that if the measured impedance is above a critical high impedance, application of the radiofrequency electromagnetic energy to the skin is stopped.

30. A skin treatment device according to any one of claims 22 to 29, wherein the first electrode and the second electrode are incorporated into at least a first distally extending arm and a second distally extending arm, respectively, of the device.

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 of claim 30, wherein the at least first and second arms are fixed.

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